Improve Kiln-Dried Lumber Production with Proper Boiler Water Treatment

The lumber industry is challenged with meeting high demand while simultaneously controlling costs – especially when labor and parts/equipment are in short supply. This makes it extremely important that the production process is optimized to be fast and efficient with minimal downtime while creating quality lumber with little waste.

One of the most important aspects of kiln dried lumber production is controlling the moisture content in the wood. Drying the wood effectively until it reaches the proper moisture level is critical for producing quality lumber. Improper moisture content can affect the appearance, dimensions, and strength of the wood, and potentially yield lumber that cannot be used.

Kilns are often used to dry wood during the lumber production process. Since wood takes on the moisture content of its surroundings, it is imperative to precisely regulate the environment during kiln drying. Kilns use air flow, steam injections, and temperature to control the humidification of the wood and reach desired moisture levels.

Steam boilers are used to supply steam during this lumber kiln-drying process. High-quality, pure steam is essential for properly controlling the humidity in the kiln.

Issues from Steam Boiler Carryover
A common issue that can occur with steam boilers during lumber production is carryover. Carryover is a phenomenon where liquid water and impurities get carried out with the steam from the cycled-up boiler water due to poor steam-water separation. This means that the steam is no longer pure and can become very problematic for kiln drying operations.

If boiler water is carried into the steam line and injected into the kiln, it can cause damage to both the lumber and the kiln structure itself. Because carryover produces low-energy, low quality steam, the results are inconsistent drying and conditioning times which can cause variations in lumber quality, negatively affecting its value. Carryover also accelerates corrosion in kiln coils, steam lines, and equipment downstream of the boilers.

Additionally, carryover can cause a sharp drop in boiler efficiency, lead to water hammering and erratic boiler behavior, and make it difficult to manage any chemical program. In summary, carryover can seriously affect the operation and health of your entire steam system and greatly increase costs by increasing boiler fuel use. These semi-hidden costs must be eliminated in today’s business environment.

What Causes Carryover?
Carryover can occur in your steam system for a number of reasons. Fluctuating steam demand (often seen in kiln-drying yards), low operating pressure, poor water chemistry and control, and improper plant design can all promote boiler carryover.

Many kiln drying lumber producers may not be aware that issues with their equipment, delays in production, or damaged lumber are the direct result of boiler carryover. Once identified as a problem, the challenge becomes how to effectively correct it.

One common approach to curb carryover in systems that struggle to maintain good steam-water separation is to increase boiler blowdown. However, increasing the blowdown rate is a costly method and a waste of energy, water, and treatment chemicals.

Boiler water chemistry is another way companies attempt to thwart carryover. However, many of the conventional chemical treatment programs that are often used are problematic because they add more and more dissolved solids to the water. These solids, along with other impurities, contribute to the carryover-potential of the boiler water, which can only be removed via boiler blowdowns. Again, increasing blowdown results in greater utility and chemicals consumption and higher costs.

Corrosion from Standard Operation of Kilns
Even without boiler carryover, other aspects of standard kiln operation can lead to corrosion of the metal inside the kiln. Lumber yards rotate their kilns to keep an efficient production schedule. Kilns are often cycling between drying, conditioning, and remaining idle. The continual wet/dry operation of equipment causes metal surfaces to become susceptible to oxygen, carbonic acid attack and flash corrosion. Any leaks in coils and steam/condensate piping will draw in air (oxygen and CO2) whenever a vacuum is pulled and accelerate the corrosion process.

“Oxygen and carbon dioxide can also be drawn directly into the coil through leaks of various kinds. This commonly occurs after the steam supply valve closes and the residual steam condenses, drawing a slight vacuum”.1

Due to the nature of kiln operation, flash and oxygen corrosion is of particular concern for equipment and, when left unchecked, results in costly failures and untimely maintenance.

Clarity Has the Solution:
A water treatment program from Clarity Water Technologies featuring our proprietary technology, EcoSHIELD™, has proven to be extremely effective in preventing boiler carryover during lumber production. This state-of-the-art technology is more effective, economical and eco-friendly than traditional chemical solutions.

EcoSHIELD™ was designed to replace conventional water treatment methods and eliminate the use of chemicals that add dissolved solids to the boiler water. This greatly lowers the carryover potential of the water and significantly reduces blowdown, thus conserving energy, water, chemical, and sewage costs.

Additionally, EcoSHIELD™ is the perfect solution to combat the types of corrosion and scale deposition typically observed in kiln drying yards. It forms a molecular protective bond with the metal surfaces of the boiler and inside the kilns, extending the life of these assets while reducing the chances of unscheduled shutdowns due to corrosion-related issues. The film created by EcoSHIELD™ on metal surfaces lasts at least 2 weeks, which has been proven to greatly reduce/stop flash corrosion inside the steam supply and return piping (and heat exchangers) between run cycles.

Controlling Iron Levels Limits Corrosion:
The graph below displays dissolved iron trends for a current Clarity customer in the kiln drying lumber industry. Active corrosion rates correlate to the level of dissolved iron in the water. Before beginning the EcoSHIELD™ program, this customer was experiencing high rates of corrosion and dissolved iron in their feedwater supply to the boilers, as iron concentration was nearly 1 ppm in the boiler feed water prior to starting. Since moving to Clarity’s EcoSHIELD™, iron levels have dropped and remained consistently below ASME’s water chemistry guidelines for boiler feed water (<0.1 PPM for low pressure boiler systems).

Kiln dried lumber mill graph of feed water iron
Efficiency loss from scale deposits in steam boilers

There are additional benefits of achieving low feed water iron levels. There is less iron cycled up in the boiler, which greatly reduces the potential for boiler scale that contains this iron. Just 1/16th inch thick of scale in a steam boiler results in 12.4% increase in fuel use. Also, dirty boiler water polluted with insoluble iron further increases risk of boiler carryover. Boiler water, at full cycles, should be crystal clear.

How Clarity Can Help:
Clarity’s technical consultants have extensive expertise in a variety of water treatment applications, including kiln dried lumber production. A custom water treatment plan from Clarity that incorporates EcoSHIELD™ will help lumber mills prevent steam boiler carryover. Our proprietary technology will have your boilers running at peak performance while protecting your equipment from corrosion and reducing the need for blowdown. Clarity’s EcoSHIELD™ will limit production issues related to carryover, conserve energy and water, and lower your total cost of operation!

If you are experiencing symptoms of carryover or have issues with corrosion, give us a call. We’ll do a FREE evaluation of your entire system to assess your process and help customize a water treatment plan for your facility!

1 Carroll, Steven W, Western Dry Kiln Association, and Nev.) Western Dry Kiln Association. Meeting (48th : 1997 : Reno. Steam-side Coil Corrosion In Dry Kilns. : Corvallis, Or. : Western Dry Kiln Association, 1997.

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Ten Huge Mistakes Facilities Make in Boiler Operation and How to Avoid Them

Water Treatment Tips You Should Consider During Spring Boiler Maintenance

Steam boilers normally work their hardest during the cold winter months supplying comfort heat to buildings. As the snow melts away and the warmer weather approaches, the loads on steam boilers are often greatly reduced. Facilities that use boilers exclusively for heat begin to ramp down their boilers in the Springtime and, in some cases, shut them down until the Fall. This presents the ideal opportunity for facilities to start the yearly maintenance required to keep these vital systems operational and running efficiently.

So, where do you start? As a water treatment company that has treated and serviced thousands of steam boilers, we wanted to share some tips to help as you put together a Spring maintenance plan for your boiler.

IMPORTANT:  Never attempt to fix a mechanical or chemical issue unless you are trained and certified to do so. Safety should always come first. Consult a specialist before starting any mechanical or chemical related projects if you are not trained and certified to perform the work.

Shutting Down Your Boiler Before Performing Your Spring Boiler Maintenance

For some, taking the boiler offline for maintenance may only be for a few days. However, if your facility takes your steam boiler offline for the entire warm weather season, you’ll need to consider laying up the boiler. There are two primary methods of laying up a boiler: wet lay-up and dry lay-up.

We have informative articles that provide tips on both methods, including how to decide which one is appropriate for your facility:

Perform the Necessary Mechanical Steps Specific to Your Boiler and Location

Oftentimes, when facility engineers begin to think about their annual boiler maintenance and inspection, the mechanical operations of the boiler are top of mind. This is a great way to start. Along with standard maintenance and required inspections, there are a number of checks that should be done to identify potential issues and areas that require attention.

While boilers must be inspected each year, each state’s requirements vary so we will not cover that here.  Make sure you are familiar with your state’s boiler inspection requirements. 

When performing routine checks, cleanings, and repairs on your boiler, keep in mind that every boiler is different.  Refer to recommendations from the manufacturer of your specific boiler.  You should incorporate these recommendations into your Spring boiler maintenance plan so that you have your own specific checklist of mechanical tasks.  Here are some general steps to consider.  Keep in mind that this is NOT a comprehensive list. 

  • Perform routine checks, cleanings, and repairs:  Check safeties and general controls.  Check the refractory for any cracks.  Clean the internal fireside and water side tubes and shell (if your tubes don’t look this, THEN CALL US!).  Repair and replace seals, gaskets and valves. 

Include Water Treatment in Your Spring Plan

Spring is also an ideal time for you to investigate the performance of the chemical treatment program for your boiler. Some people defer to the approach of “if it aint broke, don’t fix it” with regards to their boiler chemistry. However, with rising utility costs and major advancements in the science of treating steam boilers, it would be wise to give some thought to your boiler water treatment. Plus, with steam loads and requirements at their lowest, it provides the opportunity to make the necessary improvements/enhancements without an interruption to your facility’s needs. If possible, involve your water treatment consultant in this assessment, as they will have the expertise to properly assess your program.

6 Areas to Address During Spring Boiler Maintenance

We highly recommend including a host of checks during your Spring boiler maintenance to determine if your steam system is running as efficiently as it can be. Since we are water treatment experts, we will focus on aspects of your steam system related to boiler water. So, what are some of these items that should be examined during this time? Let’s take a look at 6 areas you should address every Spring.

  1. Analyze the makeup water source for the boiler.  Has anything changed from last year (dissolved solids level, water quality, hardness, alkalinity)? Does the municipality utilize monochloromine as its disinfection technology?

  2. Investigate the performance of your pretreatment systems.  Has the throughput changed?  Has the hardness of your makeup source changed?  How old is the resin in your softener or dealkalizer vessels?  Is this the time to send your resin out for analysis to see how much life is left?  Are other pretreatment technologies now required due to changes in steam usage or makeup quality?  Do you have a water meter on your softener?

  3. Assess your feedwater tank or deaerator.  When was the last time you conducted a dissolved oxygen study on it? When was the last time it was opened for inspection? Is it operating at designed temperatures and pressures?

  4. Inspect the condensate system.  Do you have a steam trap maintenance program? Have you had to (or do you need to) replace return piping?  If so, why? Are you tabulating your condensate return percentage? Note: you should. Now is the time to examine and make repairs to return to optimal efficiency.

  5. Evaluate the boilers.  Are automated surface blowdown controls savings (water, fuel and chemistry) worth the investment?  What does the deposit look like on the boiler?  What is the site glass condition?  Have loads on the boiler gone up or down?  What was your fuel consumption this year compared to previous years

  6. Consider your overall water treatment process.  Are you still using day tanks (is it still 1973?)?  Are operators still hand mixing chemistry?  Are you feeding chemistry into the proper locations?  Are you still using 30-40 year-old technology?  What would the benefits be for new technology?

If you cannot safely and effectively perform the steps above, or you cannot answer the questions posed, you should contact a boiler and/or water treatment specialist.  They will be able to perform the required maintenance and help you determine if your boiler system may have issues that need to be addressed.

This is by no means a comprehensive list of all the checkpoints one should go through when maintaining their steam system and examining their boiler water treatment.  However, being able to positively determine the answers to these questions can help you make the proper adjustments to get your steam systems running at peak efficiency.  Rest assured that the money you can save will make it well worth it!

Download Our Handy Spring Boiler Treatment Checklist

To help you with your Spring maintenance, we’ve pulled information from this article into a printable Spring Boiler Treatment Checklist. The checklist focuses on the aspects of your steam system that are related to boiler water treatment. It does not include the required inspections and routine maintenance checks, cleanings, and repairs since those tasks will differ based on your specific boiler system and the state where you’re located.

You can fill out this handy checklist as you plan for and perform your Spring boiler tasks. Plus, you can record notes to help when you do it all again next Spring.

Click here to download the PDF.

How Clarity Can Help

Proper water treatment, along with regular inspections and maintenance, can ensure your entire steam system operates at peak efficiency. Additionally, it will reduce unplanned downtime and maintenance costs and will extend the life of your equipment.

Clarity’s water treatment experts have extensive experience with steam boilers. If you have any questions as you plan and perform your Springtime boiler maintenance, or if you need any help, please contact us! We’ll be happy to come out and conduct a free evaluation of your facility and look for ways to save you money!

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Ten Huge Mistakes Facilities Make in Boiler Operation and How to Avoid Them

How Canning Facilities Can Prevent Rusty Cans

When consumers pop open a can of their product of choice, it’s pretty simple. If they enjoy what’s inside, they’ll most likely stock their shelves with that product again. Their satisfaction with the product will drive that future decision. They’re certainly not saying “wow, that can looks great, so I’m going to buy more!” And, they’re most likely not thinking about what it takes to get that product into the cans so they can buy more from their favorite brick-and-mortar or online store.  But behind the scenes lies a very complex process to get high quality product into clean, rust-free cans.

A Major Challenge for Canning Facilities

The canning process is very involved. It requires precise engineering and careful execution to run a safe, efficient process that preserves the quality of the contents. With the rising costs of raw materials, energy and labor, it’s more challenging than ever to maintain an efficient process. There’s no room for waste.

A common issue for canning facilities that severely impacts efficiency is tainted cans from ineffective water treatment during the canning process. There aren’t many options once you have a batch of cans that are rusted and contaminated. Manually cleaning the cans is labor-intensive, time-consuming, and costly. When cans are beyond salvaging, it leads to a great deal of wasted material and product, and replacing the production means more energy use and labor hours. In the end, this inefficiency and loss of production hurts the bottom line.

Good News: There’s a Technology to Eliminate This

In the past, food companies just accepted that a certain percentage of cans will be lost in the process due to can quality. They’d have to account for it in their planning and budget. Clarity has seen companies with up to 22% can rejection rates, which is a significant hit to the bottom line. Luckily, things have changed for the better.

There is now advanced water treatment technology that will properly treat the water used in the canning process and will eliminate the issue of tainted cans altogether. No more loss in production due to this issue. No more wasted time, energy, and money to compensate for the lost cans. In addition, this technology will prevent your retorts from corroding, so no more production issues from corrosion.

Clarity Has the Solution

The solution is a retort treatment program from Clarity Water Technologies featuring our proprietary EcoSHIELD™, a state-of-the-art technology that has proven to be extremely effective in the metallurgical protection of cans and retorts from the heating process. EcoSHIELD™ is a more economical and eco-friendly way to protect your cans and reduce the number that deteriorate. This technology is changing the entire industry.

EcoSHIELD™ forms a molecular protective bond barrier to the can’s surface that protects it from corrosive properties of the heated washwater. Unlike conventional treatment programs, it yields wastewater that is both eco-friendly and free from metals. And, it provides food-grade protection, so it’s safe for your canning process.

This technology also prevents stainless steel and mild steel retorts from corroding thanks to this molecular bond. It extends the life of these assets while reducing the chances of unscheduled shutdowns due to corrosion related issues.

The Proof is in the Pictures

Ugly, rusty cans may be an unwelcome but familiar sight at canning facilities. Unfortunately, cans like the ones below are all too common. These come from one of Clarity’s customers BEFORE their canning system was treated with EcoSHIELD™.

Tainted, rusty can from improper water treatment
Tainted, rusty cans from improper water treatment
Rusty can basket from improper water treatment

Once Clarity implemented a water treatment plan using EcoSHIELD™, that same facility saw drastic improvements almost immediately. The batch of immaculate cans below was treated with EcoSHIELD™. Any canning facility can achieve these results with a plan from Clarity.

EcoSHIELD™ Can Also Protect the Steam Boilers at Canning Facilities

The same benefits described above for retorts also apply to the steam boilers at canning facilities. A customized water treatment plan from Clarity implementing EcoSHIELD™ technology will improve steam boiler efficiency, extend the life of the system, reduce fuel and water consumption, and lower the cost of operating your steam system.

EcoSHIELD™ is different from traditional chemical treatments because it protects the metal surfaces of the entire steam system. It creates a tenacious barrier between water and metal that inhibits scale formation and corrosion, ultimately improving heat transfer and boiler efficiency.

It facilitates the reduction of feedwater conductivity, which enables your boiler to run at higher cycles of concentration. This yields an increase in efficiency by reducing boiler blowdowns, thus decreasing both the amount of makeup water taken on, salt used to soften the makeup water, and the fuel used to heat the makeup water. Not only are blowdowns decreased, but EcoSHIELD™ is also a much more environmentally friendly product to send down the drain than the traditional boiler treatments that contain heavy metals, phosphates, and sulfites.

EcoSHIELD™ works with a feedwater tank and does not require a functioning deaerator. Broken or poor-performing deaerators don’t need to be fixed to use this chemistry.

How Clarity Can Help

Tainted cans can be a huge problem at canning facilities. However, a water treatment plan from Clarity that incorporates EcoSHIELD™ can eliminate rusty, contaminated cans while simultaneously protecting your retorts. Our expertise with the technology will help you protect your steam boilers so they are running at peak performance and saving you money.

Clarity’s technical consultants have extensive expertise in a variety of water treatment applications, including the canning process. We will do a FREE evaluation of your entire system to assess your process and help customize a water treatment plan for your facility.  To schedule an evaluation, or if you are experiencing any problems or have questions, please contact Clarity Water Technologies today!

How Breweries Can Save Energy and Money with Proper Water Treatment

One of the most important issues craft brewers are trying to resolve is how to become more sustainable.  While things like packaging and shipping pose environmental challenges, the brewing process itself generally consumes a great deal of energy and water.  One of the main culprits is an inefficient steam boiler. 

Ready for the good news?  There is a quick and easy way to improve the efficiency of your steam boiler operation.  A proper water treatment program can make huge gains in energy and water conservation during the brewing process.  Not only does this help you become greener, it will also greatly reduce your operating costs! 

An Eco-Friendly Solution for Steam Boilers

When it comes to running an efficient steam system, EcoSHIELD™ is the perfect fit for breweries. This is because most breweries use steam to heat brewing vessels with steam jackets, and thus, return most of their condensate, which we call ‘liquid gold’ in the water treatment industry. The ability to return condensate is the most significant factor affecting steam boiler efficiency for several reasons.

  1. Returning condensate means you have to take on less water from the city tap, saving on your water bill.
  2. Any city water taken on must first be softened. Taking on less water means you’ll use softener salt at a lower rate.
  3. Significant fuel savings occur as most returned condensate is relatively hot (130°F to 225°F) reducing the amount of cold makeup water (50°F to 60°F) that must be heated. Energy in condensate can be more than 10% of the total steam energy content of a typical system.
  4. Condensate is as pure as the water gets, essentially distilled water containing low levels of dissolved solids. The fewer solids you add to your boiler, the less often you have to blow it down, saving water and sewer costs.

Why EcoSHIELD™?

EcoSHIELD™ is an example of Clarity’s ability to develop unique blends tailored to a customer’s specific water treatment needs.  It is an enhanced chemistry that protects the metallurgy of the entire steam system and allows greater conservation of water and fuel than traditional chemical programs. It is one of the most effective, state-of-the-art, and environmentally-advanced water treatments on the market.

Why is EcoSHIELD™ an ideal fit to use in systems that return the majority of its condensate like Craft Breweries?

  1. EcoSHIELD™ can be recycled through the condensate return, requiring you to feed less chemical into the feedwater tank.
  2. EcoSHIELD™ keeps heat transfer surfaces (inside the kettle and hot liquor tank steam jackets) clean and has even been shown to assist heat transfer better than a bare metallic surface.
  3. EcoSHIELD™ doesn’t contain any solids, further reducing boiler blowdown frequency.

Protecting Your Equipment from Corrosion and Scale

In addition to what EcoSHIELD™ does differently to boost boiler efficiency, all boiler treatments aim to limit the corrosion of the system and prevent scale from forming on the boiler tubes. There not a more effective way to treat a steam system than with EcoSHIELD™ due to the protective passivation formed on all metallic surfaces it touches. Lengthening the lifespan of your steam system and the steam side of brewing equipment saves lots of money in the long run. Preventing scale formation on boiler tubes is manageable with a water softener and an effective boiler treatment like EcoSHIELD™, but it can become very costly if left unchecked. By insulating the boiler tubes, scaled boilers have to use more fuel to achieve the same level of heat transfer. A mere 1/8th inch of scale requires a fuel increase of 25%!

See the Results:  A Brewery Case Study

A great example of a brewery taking advantage of the efficiency gains afforded by using EcoSHIELD™ is Rhinegeist Brewery in Cincinnati, Ohio.

Clarity has been a fantastic partner in maintaining our boiler chemistry and I recommend Clarity to everyone I know installing a steam system.

Cole Hackbarth, Rhinegeist Brewery

An analysis of the water testing data gathered at Rhinegeist demonstrates just how efficiently their boiler operates. Below is a chart showing the conductivity of water collected at different points of interest in their system. Conductivity is a measure of how easily the water can carry an electrical current and is a good measure of the number of solids present in the water sample.

As mentioned previously, the condensate is the purest water in the system. The feedwater is a blend of condensate return and city water, but it is still very pure since Rhinegeist consistently returns over 90% of their condensate. The day this data was gathered, their feedwater consisted of 92.02% condensate and 7.98% city water.

Cycles of Concentration (COC) is another good way to gauge boiler efficiency. It is calculated by dividing the conductivity of the boiler water by the conductivity of the feedwater. This essentially tells you how many cycles the feedwater can be reused before the boiler needs to be blown down to remove solids that have accumulated as steam is driven off. By calculating COC, you can also do a quick calculation for blowdown percentage.

We aim for 50 COC in the boiler because there are diminishing returns on efficiency once you start getting higher than 50 COC, making running higher cycles not worth it unless local sewer costs are expensive.

In addition to the energy savings Rhinegeist has made, their steam system and brewing vessels are being protected against corrosion exceptionally effectively. Iron oxide corrosion can never be completely stopped, only slowed; thus, the American Society of Mechanical Engineers (ASME) sets the guideline for effective corrosion control at an iron concentration of 0.10 ppm in the boiler feedwater. Our goal is to be below this number, and with EcoSHIELD™ and proper boiler operation, that is the norm. The feedwater iron level upon the most recent data at Rhinegeist was 0.02 ppm, which is the lowest the iron measuring device can read before hitting zero. Iron was also tested in the condensate, which is the most corrosive water in the steam system (because it’s so pure and wants to dissolve anything it touches), and the result was also 0.02 ppm iron.

How Clarity Can Help

In addition to the advantages EcoSHIELD™ affords in returning condensate and protecting against corrosion, it is unmatched in its ability to increase energy efficiency and save money. For an industry that cares deeply about green initiatives, EcoSHIELD™ is a straightforward way to reduce water, fuel, and effluent loading costs.

Clarity has extensive experience with boiler operation in brewing applications.  We will do a FREE evaluation of your entire system to ensure your water is properly treated and you are operating at peak efficiency.  To schedule an evaluation, or if you are experiencing any problems or have questions, please contact Clarity Water Technologies today!

Why Craft Breweries Need to Avoid Steam Boiler Carryover

Steam Boilers an Important Factor in Successful Brewing

As the craft brewing industry continues to boom, Brewmasters across America are continually refining their skills to create exceptional beers to please the palates of every beer drinker.  While finding just the right mix of the perfect ingredients is key to a flavorful beer, brewers are also finding that their system and operations plays a huge role in the quality of the beer they produce.

Heating is an integral part of the brewing process, and steam boilers provide the best option for heating kettles and hot liquor tanks.  However, for most people, operating a steam boiler is a foreign venture.  But, with some basic knowledge of proper boiler operation, you can ensure that your equipment is receiving high-quality steam so that you can brew a consistent product.  On the flipside, improper boiler operation and care can lead to problems with your batches and equipment, proving to be very costly.

What is Boiler Carryover?

One of the most common operational issues that boiler novices encounter is known as boiler carryover. Boiler carryover is the term used when boiler water, as opposed to pure steam, gets pulled into the steam lines. Strictly speaking, in terms of personal safety, boiler carryover isn’t usually dangerous unless allowed to persist for weeks or months, corroding your steam lines. In the short term, however, it can affect heat transfer and create inconsistencies that impact your brewing.

The Impact of Carryover on Your Brewing

Boiler carryover can affect heat transfer in your equipment, which is critical since consistency is king when it comes to the kettle boil cycle. It can also cause excessive water hammering in your steam lines and heat exchange equipment.  The violent rattling of the piping can cause secondary issues in the short term.

Because the kettle boil cycle for wort evaporation process is so time-sensitive, it’s important that the kettle is receiving heat at the consistent rate you expect it to. Time and heat-sensitive variables during the wort evaporation include:

  • Reaching a desired wort evaporation percentage
  • Maintaining a vigorous boil
  • Driving off dimethyl sulfides (DMS) that have an undesirable vegetal flavor
  • Protein coagulation and removal
  • Aromatic flavor profile of the hops
  • Sugar profile

Should the heating of the kettle be interrupted by a carryover event, it is extremely difficult to recover that batch when you have this many time-sensitive processes occurring simultaneously. For example, if you lose some heat due to carryover, you have to extend the boil-off time to achieve the same wort evaporation percentage. By doing so, you’re going to also end up driving off more of the desired aromatic flavors from the hops. Brewing is a science, and it’s impossible to do good science when you have multiple related variables being disturbed at the same time.

How to Avoid Boiler Carryover

Now that you know why avoiding carryover is so important, let’s discuss why it happens and how it can be avoided. When analyzing boiler treatment, it’s important to break it down into three aspects of mechanical, operational, and chemical solutions.

  1. Mechanical: First of all, it’s important that the mechanics of your system are plumbed correctly. For example, the steam header coming out of the top of your boiler should extend several feet up (at least 8’ recommended) before leveling off in the rafters. This is simply because the higher the steam header extends, the larger the pressure differential holding the water in the boiler is, thus making it far more difficult for boiler water to make it all the way up to where the piping levels off. The steam lines should never dip below the water level in the boiler, or a carryover event will lead to water being continuously siphoned out of the boiler. As ridiculous as that sounds, we’ve seen it. Also, the further away the equipment that uses steam is away from the boiler, the better.
  1. Operational: Operationally, there are a few ways to fight carryover. For one, the higher pressure you can run your boiler at, the better. Higher pressure in the vapor space of the boiler helps hold the water in the boiler. Because so many craft breweries have small (~25 HP) boilers that operate at a maximum of 15 psi, this is a weak spot they face in fighting carryover. How you operate your steam valves also plays a role. Opening steam valves is similar to opening a carbonated beverage. If you open your soda very aggressively, the quick pressure differential will cause it to bubble over. Opening steam valves slowly is the best practice to avoid carryover, just like opening a soda can.
  1. Chemical: From the chemical aspect, avoiding carryover is simple as long as you’re performing regular blowdowns. The largest cause of boiler carryover is from too high of alkalinity levels in the boiler. Some alkalinity (100ppm+) is necessary to provide a pH buffering capacity, but too much (700ppm+ in small boiler, 900ppm+ in large boiler) will start to form suds on the surface of the boiler water and increase the risk of carryover. To avoid this, you need to perform surface blowdowns, since alkalinity likes to hang out in the top 8” of boiler water. A less common cause of boiler carryover is from suspended solids in the boiler water. Boiler water should be crystal clear, or close to it, but corrosion issues in your steam system can result in rusty colored water. Suspended solids, like iron, in boiler water contribute to carryover by lowering the surface tension of the water.

One of the reasons why our EcoSHIELD boiler treatment is so effective is because, unlike traditional boiler treatment chemicals, EcoSHIELD doesn’t add solids like sulfites or phosphates to your boiler, allowing you to blow down less often. EcoSHIELD consists of volatile organic molecules that travel anywhere steam or water reaches in your system to provide a protective passivation layer without contributing to the number of total solids. Solids are most effectively removed by performing a bottom blow down. Generally speaking, it’s recommended to perform a bottom blowdown once a day to get out solids, and surface blowdowns any other time necessary to get out alkalinity.

How to Check for Carryover

You may be wondering how to know if your boiler is carrying over, and there’s a very easy way to check. Because steam is practically pure H2O, your condensate return water should be extremely low in conductivity, somewhere in between 5-20uS. Boiler water has the highest conductivity of any water in the system, usually around 2500-3500uS. If the conductivity of your condensate return water exceeds 50uS, that is a clear indication that boiler water is being pulled into your steam lines.

If the carryover gets bad enough, you can get caught in a pretty vicious carryover cycle. The way to fight carryover is by blowing down the highly concentrated boiler water and replacing it with fresh feed water. However, if your boiler is carrying over so badly that boiler water is traveling back to your feedwater tank via the condensate return system, then the water you’re blowing down is being replaced by feed water that is equally contaminated. At this point, the best practice is to completely drain your condensate and feed water tanks to rid them of boiler water, and then look to start blowing down your boiler once your feed water is back in shape.

How Clarity Can Help

Boiler carryover can be quite a nuisance, but with the proper blowdown procedure and effective chemical treatment, it can be easily avoided. The steam boiler is the heartbeat of your operation, and issues with carryover can cost you heavily in terms of inconsistent products and lost production time. By taking the time to learn proper steam boiler treatment and operating it with care, carryover can be a thing of the past.

Clarity has extensive experience with boiler operation in brewing applications.  We will do a FREE evaluation of your entire system to ensure your water is properly treated and you are operating at peak efficiency.  To schedule an evaluation, or if you are experiencing any problems or have questions, please contact Clarity Water Technologies today!

Avoiding Legionella in Hotels in the Times of COVID-19

The travel and hospitality industries have been among the hardest hit during the COVID-19 pandemic. Both personal and business-related travel took a drastic dip for a number of reasons. Many events and venues that would normally draw crowds from afar have had to operate at limited capacity or even shut down completely during the pandemic. Businesses have turned to Zoom calls and virtual events instead of in-person interactions. And, of course, many people just simply haven’t been comfortable with traveling, vacationing, and attending events due to safety concerns.

All of this has resulted in fewer people staying in hotels during the pandemic. It is magnified by the drop-off in events like weddings, banquets, and business meetings, which are often held at hotels and directly lead to attendees booking rooms for overnight stay. You also have hotel restaurants and bars operating at limited capacity or moving strictly to takeout models.

Reduced Water Usage at Hotels

The decline in hotel guests, events, and food services means there’s less use of things like sinks and showers in the guest rooms, as well as the hotel pools, spas, restrooms, kitchens, and bars. This often results in hotels experiencing a drastic reduction in overall water usage.

Are you managing a hotel or extended stay facility during this global pandemic? Have you experienced limited occupancy, turned off water features, and even had to close pools and spas? If so, it is extremely important that you’re not overlooking necessary and routine water maintenance in your facility. While you have surely adopted COVID-19 protocols to provide guests with a clean, safe, and comfortable environment, don’t let your water system lead to other dangerous problems.

Dirty Water and Potential Dangers Lurking

As a leader in the water treatment industry, we at Clarity Water Technologies have noticed that hotel facilities are experiencing an uptick in customer complaints about dirty water. This, if left unchecked, could lead to a rise in detectible cases of Legionella pneuemopila in system building water. Clarity can help make sure you’re not inadvertently enabling the growth of a dormant waterborne bacteria.

How Limited Water Usage Can Lead to Problems in a Hotel

Continuous water movement in a facility protects and maintains high quality potable water. Hotel guests’ use of sinks, showers, and tubs, as well the hotel’s operation of areas like pools, spas, and kitchens, draw fresh water into the system. When water usage drops, cold water from an incoming main will sit in your plumbing and adjust to the ambient temperature. These tepid water temperatures are a breeding condition for bacteria, many of which exist naturally in water. One such bacterium is, Legionella pneumophila. Legionella bacteria is responsible for Legionnaires’ disease, which is a form of pneumonia that includes cough, shortness of breath, fever, muscle pain, and headaches. This bacterial infection, when introduced into a healthy person, can be fought off; however, those who are immunocompromised can develop severe, and even fatal, cases.

Bacteria Growth in Hot Water Systems

While Legionella exists in cold water, we see it proliferate in a facility’s hot-water system. It is here where incoming water mixes with the hot-water return and feeds into a hot water heater. Some facilities use instantaneous hot-water heaters, while other facilities prefer upright hot-water tank heating systems. Upright hot-water tank heating systems will typically heat water in a profile like manner. That means there is the unequal heating within the tank that forces convective motion, much like boiling pasta on the stove. This convective process in a large vessel can encourage dissolved solids to precipitate or fall out of the heated water. These sediments can build on heating elements and also begin to fill the basin of hot-water tanks.

To prevent sediment buildup as well as a decrease in heating efficiency, hot-water tanks must be addressed regularly. When sediments adhere to heating elements, heat-transfer decreases and the water will not become as hot as thermally designed. This can and will limit the “thermal killing effect” a hot-water heater may provide on living bacteria. If bacterium is not eliminated due to lower-than-specified high temperatures, that bacteria will most likely continue to grow both within the tank as well as the distribution system. Essentially, you supercharge the growth of the bacteria and continue to cycle that unused water within the system. Fresh cold water, from the incoming water main will bring nutrients for the bacteria to feed on and now you have created a vicious cycle. Again, if you experience these or similar issues, we can address these problems with effective interventions.

How Clarity Can Help

The COVID-19 pandemic has been difficult for everyone. Clarity has seen first-hand the toll it has taken on the hospitality industry. As water usage remains low, natural waterborne bacteria continues to build in facility plumbing. Clarity has the experience, technology and infrastructure to provide building remediation services. With a facility-wide approach, we can disinfect and flush currently-stagnated plumbing systems and provide ongoing integrated water maintenance plans. In situations where waterborne bacteria continue to exist, we can also accommodate those facilities with state-of-the-art online disinfection systems that will provide your building with a secondary form of potable water disinfection.

If you are experiencing these problems or you are looking for help in better understanding your building water, please feel free to reach out to Clarity Water Technologies with any questions or comments.

Avoiding Legionella in Nursing Homes in the Time of COVID-19

Nursing homes have instituted a number of safety protocols during the COVID-19 pandemic, changing many aspects of their daily operations in order to protect the health and wellbeing of residents and employees.  These measures, along with reduced occupancy, have often limited overall foot traffic throughout a facility and have led to reduced usage of some sinks, showers, bath tubs, and even entire wings.

Are you managing a healthcare facility during this global pandemic?  If so, this may sound familiar.  With so much focus rightly being placed on COVID-19 protocols, it is important to make sure you are not overlooking necessary and routine water maintenance in your facility.  Proper water treatment is especially critical as nursing homes and other healthcare facilities experience reduced water usage.

A Rise in Legionella Cases

As a leader in the water treatment industry, we at Clarity Water Technologies are seeing this limited water usage lead to a rise in detectible cases of Legionella pneuemopila in system building water.  Of course, we understand the necessary protocols and standards for maintaining a healthy and safe patient population during these terrible times of COVID-19.  However, in trying to fend off one virus you may be enabling the growth of a dormant bacteria.  Clarity can help you with this delicate balancing act.

Limited Water Usage Can Lead to Problems in a Facility 

Continuous water movement in a facility is paramount in protecting and maintaining high quality potable water.  That being said, when facilities limit the use of sinks, showers, and tubs, these outlets no longer draw fresh water into the system.  When water usage drops, cold water from an incoming main will sit in your plumbing and adjust to the ambient temperature of a given facility.  These tepid temperatures are usually around 50F to 70F, which is a prime temperature to grow a common bacteria found in all natural waters, Legionella pneumophila.  This bacteria is responsible for Legionnaires disease which is a form of pneumonia that includes cough, shortness for breath, fever, muscle pain, and headaches.  This bacterial infection, when introduced into a healthy person, can be fought off; however, those who are immunocompromised can develop severe and even fatal cases.

Bacteria Growth in Hot Water Systems

While Legionella exists in cold water, we see it proliferate in a facility’s hot-water system.  It is here where incoming water mixes with the hot-water return and feeds into a hot water heater.  Some facilities use instantaneous hot-water heaters while other facilities prefer upright hot-water tank heating systems.  Upright hot-water tank heating systems will typically heat water in a profile like manner.  That means there is the unequal heating within the tank that forces convective motion, much like boiling pasta on the stove.  This convective process in a large vessel can encourage dissolved solids to precipitate or fall out of the heated water.  These sediments can build on heating elements and also begin to fill the basin of hot-water tanks. 

To prevent sediment buildup as well as a decrease in heating efficiency, hot-water tanks must be addressed regularly.  When sediments adhere to heating elements, heat-transfer decreases and the water will not become as hot as thermally designed.  This can and will limit the “thermal killing effect” a hot-water heater may provide on living bacteria.  If bacterium is not eliminated due to lower-than-specified high temperatures, that bacteria will most likely continue to grow both within the tank as well as the distribution system.  Essentially, you supercharge the growth of the bacteria and continue to cycle that unused water within the system.  Fresh cold water, from the incoming water main will bring nutrients for the bacteria to feed on and now you have created a vicious cycle.  Again, if you are experience these or similar issues, we can address these problems with effective interventions.

How Clarity Can Help

2020 has been a tough time for us all.  Clarity has seen first-hand the toll this pandemic has taken on nursing home residents, facility managers, and staff, and how it has impacted occupancy and daily operations.  As water usage remains low, natural waterborne bacteria continues to build in facility plumbing.  Clarity has the experience, technology and infrastructure to provide building remediation services.  With a facility-wide approach, we can disinfect and flush currently stagnated plumbing systems and provide ongoing integrated water maintenance plans.  In situations where waterborne bacteria continue to exist, we can also accommodate those facilities with state-of-the-art online disinfection systems that will provide your building with a secondary form of potable water disinfection. 

If you are experiencing these problems or you are looking for help in better understanding your building water, please feel free to reach out to Clarity Water Technologies with any questions or comments.

Springtime Boiler Maintenance: Dry Boiler Lay Up

In the springtime, facility management teams start to prepare their cooling systems to come back online; you operate a facility with a commercial steam boiler that runs for 6 months out of the year and then sits idle for 6 months. When a boiler is not required to produce heat for those extended periods of time, most facilities will take that boiler “offline” and prepare it for a time of “safe inactivity.” The process is known as “laying up the boiler,” and it is performed to not only extend the overall life of the boiler, but also to reduce downtime and maintenance costs. In some cases, proper seasonal lay-up of your boiler can mean the difference between a boiler lasting for only 10 years or lasting for more than 30. This post will cover the features and benefits of performing a DRY lay-up.

We recently covered this same topic with regard to the reasons and best ways to perform a WET boiler lay-up here in a previous post.

As we did in that post, we will again assume that you have the best water treatment company in the area and, during heating season, your water treatment company maintains your boiler water treatment levels within optimal operating ranges to effectively inhibit corrosion and prevent scale within the boiler. For seasonal boilers even the best boiler water treatment program must be supplemented to prevent corrosion during the boiler’s non-operating months.

Why do I need to lay-up my boiler anyway?

Having the best boiler water treatment program on the planet may keep dissolved oxygen out of your boiler during normal operation, but it will not do you any good when your boiler is sitting idle offline. When a boiler is taken offline and allowed to cool down for extended periods of time, a boiler lay-up program is highly recommended to offset the increased levels of oxygen in the boiler. Oxygen can quickly produce pitting in steel tube sheets and boiler tubes. Once oxygen pitting starts, it can easily corrode through a boiler tube in a very short period of time. When it is time to start your boiler back up in the fall, you could first have to make a call to a mechanical contractor to plug or replace the corroded tubes. This is often a very expensive endeavor.

What do I need to do when my boiler is taken offline?

When a boiler is taken out of service, the boiler should be cooled until the water is below the atmospheric boiling point, but not below 180°F, and then the boiler should be emptied and flushed out. An inspection should be made to determine what repair work is necessary and what cleaning should be done. A decision should then be made on whether to employ dry or wet storage techniques.

Should I perform a wet lay-up or a dry lay-up?

There are two primary methods of laying up a boiler –  wet lay-up and dry lay-up. As you can imagine there are advantages and disadvantages to each. Aspects that you will need to consider in the selecting your choice of lay-up procedure are as follows:

  1. the size of the boiler
  2. the type of boiler
  3. the length of time the boiler will be offline
  4. the temperatures that the boiler will be subjected to while offline
  5. the resources that will be required to refill the boiler with treated water
  6. the resources that will be required to monitor the boiler while offline

Choosing the best lay-up method for your boiler is not always so apparent and it sometimes makes sense for you to consult with an experienced water treatment service provider.

A dry boiler lay-up protocol should be used if boiler will be shut down for an extended period or when there will be no foreseeable urgency to restart the boiler. This method is also preferable where the idle boiler may be exposed to subfreezing temperatures. Unlike a wet lay-up method, the dry lay-up also has a “set and forget it” component; it does not require constant monitoring, testing or circulation of the water.

DRY LAY UP PROCEDURES

This procedure is preferable for boilers out of service for extended periods of time or in locations where freezing temperatures may be expected during standby. It is generally preferable for reheaters.

  1. The cleaned boiler should be thoroughly dried, since any moisture left on the metal surface would cause corrosion. Precautions should be taken to preclude entry of moisture in any form from steam lines, feed lines or air.
  2. A moisture absorbing material, such as quicklime (2 lb. per 30 cu. ft.) or silica gel (5 lb. per 30 cu. ft. of boiler volume) may be placed on trays inside the drums to absorb moisture from the air. The manhole should be then closed and all connections on the boiler should be tightly blanked. The effectiveness of the materials for such purposes and the need for their renewal may be determined through regular boiler inspections. This should be done every three months. If there is high humidity, this should be done more frequently. If quick lime or a non-indicating silica gel is used, desiccant plates with indicating dye should be placed on each tray with the absorbing material as a quick indicator. These plates will change from cobalt blue color to pale pink if the absorbing material is exhausted and loses its effectiveness.
  3. Alternatively, air dried externally to the boiler may be circulated through it. The distribution should be carefully checked to be sure the air flows over all surfaces.
  4. In the case of a high humidity area or a boiler that has been prone to off season corrosion in the past, there is another method of dry lay-up that utilizes an oil-based boiler treatment product to coat the inside surfaces of the boiler. This dry lay-up method is a little more substantial and it does add some extra steps, however the results are usually worth it. If this method is used the oil-based corrosion inhibitor must be removed before the boiler is brought back online. This is accomplished by filling the boiler, adding caustic and performing a high alkalinity boil out to remove the oil-based lay-up product.

Once the boiler is flushed out and refilled with properly treated make-up water it can be slowly brought back up to working temperature and operated as normal.

When is appropriate to use a WET lay-up procedure?

So glad you asked! You can read all about that in the first part of this two-part series: Boiler 101: Why a Wet Seasonal Boiler Lay-Up May Be Right for You

I want to learn more about other important boiler water treatment services. What can I do?

Kudos to you! Learning more about what potential issues your steam boilers could face is always a good idea. There is a abundance of informational resources regarding steam boiler operation and boiler water treatment available all over the internet. A great place to start is our free boiler operation eBook that is available for instant download: “10 HUGE Mistakes Facilities Make in Boiler Operation and How to Avoid Them!” which you can download for free at the link below.

Lastly, if you have any specific questions or concerns regarding your facilities water treatment program, or if you have an emergency situation that needs attention right away, please feel free to contact one of our water treatment experts.

Thanks for reading!

Springtime Boiler Maintenance: Wet Boiler Lay Up

When Spring arrives, it is time to consider how your boiler system will spend the next few months while it sits dormant offline. If you own and/or operate a facility with a commercial steam boiler that only gets seasonal use, then this topic is for you.

When a boiler is not required to produce heat for extended periods of time, it often makes sense to take that boiler “offline” and prepare for a time of “safe inactivity.” The process is known as “laying up the boiler.”  The main reason for doing this is to extend the overall life of the boiler and reduce maintenance costs and downtime. In some cases, proper end of season lay-up can mean the difference between a boiler lasting 10 years or lasting for more than 30. This post covers the features and benefits of performing a WET lay-up. (The next post in this series will cover a DRY boiler lay-up procedure.) The wet lay-up protocol is the one that you want to use if you have a boiler that is sitting idle, but that may need to be ready to go online in a hurry. This is also known as a standby boiler.

For the purposes of this post we will assume that you have the best water treatment company in your area and, during heating season, your boiler water treatment levels are maintained within specific optimal operating ranges to effectively inhibit corrosion and prevent scale. However, for seasonal boilers, during the non-operating months, even the best boiler water treatment program must be supplemented to prevent corrosion.

There are two primary methods of laying up a boiler –  wet lay-up and dry lay-up. As you can guess there are benefits and potential downfalls to each. Choosing the correct method is not always obvious and so it may make sense for you to get some guidance from an experience water treatment service provider. Some factors in the selection of lay-up include the size and type of boiler, the length of time the boiler will be offline, the temperatures that the boiler will be subjected to while offline and the resources needed to refill and monitor the boiler with treated water.

Why do I need to lay-up my boiler anyway?

When a boiler is taken off-line and allowed to cool down for extended periods of time, a boiler lay-up program is highly recommended, to offset the increased levels of oxygen in the boiler. Oxygen can quickly produce pits in tube sheets and boiler tubes. Once oxygen pitting starts, it can easily corrode through a boiler tube in a very short period of time. When it is time to start your boiler back up in the fall, you first have to make a call to a mechanical contractor to plug or replace tubes. Not good for your boiler and very expensive.

What do I need to do when my boiler is taken offline?

When a boiler is taken out of service, the boiler should be cooled until the water is below the atmospheric boiling point, but not below 180°F, and then the boiler should be emptied and flushed out. An inspection should be made to determine what repair work is necessary and what cleaning should be done. A decision should then be made on whether to employ dry or wet storage techniques.

WET LAY UP PROCEDURES

A wet procedure may be used for a boiler that is taken offline completely or for one that has been placed in a “standby” condition. Wet storage is particularly useful if the standby boiler may be required to go back online at short notice or if it is impractical to employ a dry storage procedure. The method is not generally employed for reheaters or for boilers which may be subjected to freezing or sub-freezing temperatures.

There are a few alternative procedures that may be employed in a wet lay-up. The following is the most typical:

The clean empty boiler should be closed and filled to the top with water that has been conditioned chemically to minimize corrosion during standby. It is important that water pressure greater than atmospheric pressure should be maintained within the boiler during the storage period. A head tank may be connected to the highest vent of the boiler to help maintain pressure above that of the atmosphere.

  1. For short storage periods, caustic soda and sulfite should be added until their levels in the boiler water reach 450 ppm total alkalinity and 200 ppm sulfite. If the superheater is of the drainable type, it can also be filled with the same treated water by over flowing from the boiler.
  2. If the superheater is non-drainable, it should be filled only with condensate or demineralized water containing a minimum of dissolved solids, not more than 1 ppm. Before introducing the water into the superheater, mix in uniformly about 200 ppm of hydrazine and sufficient volatile alkali, such as ammonia, cyclohexylamine or morpholine to produce a pH of 10. The treated water may be introduced into the superheater through an outlet headed drain until the water over-flows into the boiler. When the superheater is filled, close the drains and vents. The boiler can now be filled through the feedwater or other filling line with condensate, feedwater or clean service water treated as described, with hydrazine and additional volatile alkali. If the storage period is expected to exceed three months, the concentration of hydrazine should be doubled.
  3. If preferred, the boiler may be filled using feedwater or condensate treated with caustic soda and sodium sulfite after first filling the superheater with condensate treated with hydrazine and additional volatile alkali.

During the Time That Boiler is Offline

The boiler water should be circulated periodically to prevent the chemicals from stratifying or falling out of solution. The burner may be used to warm the water in the pressure vessel to stimulate natural circulation.

It is important to routinely test the water while the boiler offline to monitor the chemical concentrations. If there are any leaks in the system it can cause make-up water to be introduced to the boiler. Untreated make up water will be high in oxygen and carbon dioxide and will aid in corrosion.

Before Boiler Comes Back Online

Before starting a steam boiler that has been in wet lay-up, perform a bottom blow off to reduce the alkalinity. This reduces the chance of carryover. Confirm that all tags and locks are removed, and closely monitor the system cycles for a minimum of three to five cycles to ensure proper functioning of the boiler before allowing it to run automatically.

When is appropriate to use a dry lay-up procedure?

Great question! You can read all about that in the second part of this series: Springtime Boiler Maintenance: Dry Boiler Lay Up.

I want to learn more about other important boiler water treatment services. What can I do?

Well you’re in luck! The first step in efficient and safe boiler operation is knowledge. Learning more about what potential issues your steam boilers could face is always a good idea. There is a treasure-trove of informational resources regarding steam boiler operation and water treatment available online. Another great resource is our free boiler operation eBook that is available for instant download: “10 HUGE Mistakes Facilities Make in Boiler Operation and How to Avoid Them!” which you can download for free at the link below.

As always, if you have any specific questions or concerns regarding your facilities water treatment program, please feel free to contact one of our water treatment experts.

Thanks for reading and please check out our free eBook!

How to Avoid Boiler Failure During Cold Weather

The coldest months of the year arrive during the winter months. If you operate a commercial property, especially in the Northeast or Midwest, winter is not a good time to have a boiler failure. If you operate an industrial or manufacturing facility, there is NEVER a good time to lose a boiler! Unfortunately, this a common occurrence throughout the winter months and the culprit is very often cold feed water. Monitoring your boiler feed water temperature should be an important part of your daily boiler inspection and should be worked into your overall boiler maintenance program.

As you probably learned in high school science class, metal expands when it is hot and contract when it is cooled. Remember when the teacher filled the metal gas can with hot water, put the cap back on, and then ran the can under cold water? What happened? That’s right; the can “crushed itself” almost as if by magic. This same principle can be catastrophic to a boiler. Although modern boilers are manufactured to withstand some temperature fluctuation, they are not designed to withstand severe fluctuations or even constant “mildly” severe fluctuations. In a boiler system is manufactured to precise specifications and running at them at their intended optimal operating temperatures are vital for overall system longevity. A common and underestimated issue that plague many systems during this time of year are the effects of allowing cold feed water into a hot boiler system.

Most boiler systems are designed and installed to address this issue, however, sometime hasty planning or improper operation can cause cold water related issues to pop up. Low feedwater temperatures during boiler operation have three major negative impacts:

  1. Greatly increased fuel costs due to loss in efficiency. (No surprise here – it costs more money to heat cold water.)
  2. Increased occurrences of corrosion due to increased dissolved gases in feedwater. Oxygen pitting is common in systems with low temperature feed water. This quickly lead to premature system failure.
  3. Increased boiler water treatment Boiler chemicals are used to remove excess oxygen from feed water. The colder the feed water, the more dissolved oxygen it can hold. The more dissolved oxygen in the feed water, the more boiler chemicals needed to remove it.
  4. Increased chance of thermal shock (also known as boiler shock) which could lead to sudden pressure vessel failure, a potentially dangerous and catastrophic event. (Remember the high school professor’s gas can “crushing” demonstration?)

Cold feedwater is usually less of an issue in system that return a healthy amount of condensate (75% or more); unless that condensate travels over a very long distance. In steam systems that return very little condensate, it is necessary to make up the lost water with fresh incoming water. This “make up” water is much cooler than the steam system needs to perform at optimal levels, and therefore needs to be pre-heated before entering the boiler. The best practices for accepting this makeup water in a steam boiler is usually outlined in the boiler manufacturer guidelines and often includes some type of pre-treatment regimen. ASME guidelines often calls for water to be introduced into a steam boiler at no less than 200 degrees Fahrenheit . Pretreatment of boiler makeup water often includes, but is not limited to, chemical treatment, softening and heating of the makeup water through a deaerator tank.

What is Boiler Shock?

A hot boiler can undergo significant damage if cold water is introduced without first being tempered. This phenomenon is commonly referred to as thermal shock or boiler shock. In extreme situations of an extremely hot boiler system and extremely cold feed water, catastrophic failure can happen almost immediately, however this is typically not the case. Even though the term boiler “shock” suggests that a boiler could be effected instantaneously or suddenly, the reality is that most failures happen over time. The more typical problem is stress cycling caused by the continuous heating and cooling of the internal metal components of the boiler. Thermally induced stress cycling could be causing significant damage to a boiler system over the course of a few weeks, but could happen over months or years; and is particularly common in boilers installed in hot-water heating systems. When failures eventually do occur, they are typically due to metal fatigue. Eventually the metal breaks down due to the consistent and extreme expansion and contraction.

Failures caused by boiler shock are usually not an indication of poor boiler design or manufacturing deficiencies, but instead are due to overall plant design (cutting corners) or the manner in which the heating system is being operated or maintained.

In the following video, you can see the effect of thermal boiler shock on a boiler. In this case, cold water introduced into the boiler cause micro fissures in the tube sheet and unseated many of the boiler tubes. Depending on the size and type of boiler, this type of failure could cost tens of thousands of dollars to repair.

 

The Use of a Steam Sparger

Avoiding boiler shock is a mechanical operation. A boiler system’s own steam is sometimes used for preheating its own feedwater. The direct steam injection into the feedwater tank referred to as steam sparging. A steam sparger is often engineered into the condensate return tank of a fire tube boiler system to maximize efficiency by making sure that the boiler does not have to work harder to transform cold makeup water into steam. Sometimes a condensate return tank may be retrofitted with a steam sparger to fix a newly developed issue with low temperature condensate; however, this must be done by an experienced engineer. Some tanks were not designed to handle the increased heat that a steam sparger will cause in the feedwater. Also, the sparge design and location affect the efficiency of the process.

Sparge Pipe vs Direct Steam Injection

While installing a sparge pipe into a condensate return take is a relatively low cost and easy installation to have performed, it could have some drawbacks depending the size and overall design of your system. While a job of steam sparger in a condensate return tank is to simply maintain a feed water temperature of 200 degrees or better, the steam sparge pipe design is not always the most efficient way to do it. Sparge pipes (simple pipes with drilled steam distribution holes) tend to produce uneven water temperature control; they can also cause water hammer and heavy vibration due to collapsing steam bubbles.

Another method of heating the water in a holding tank is through a direct steam injector or steam injection heater. This type of direct steam contact offers greater control and has the capability of addressing some of the potential downfalls and inefficiencies of the sparge pipe method.

Water Treatment Alone Cannot Do The Job of Removing Dissolved Oxygen from Feedwater

Proper boiler maintenance and operation require multiple fields of expertise. While boiler water treatment is an important part of a sound boiler maintenance program, it is equally important to have system that is mechanically and operationally running at peak efficiency.

Oxygen is present in all make up water. Oxygen causes red iron oxide to form on a mild steel surfaces immersed in water. This rust is active corrosion and it will continue until the metal is completely corroded away. If the amount of oxygen in the water is limited, the iron oxide film cannot form as easily; instead, the surface of the steel tarnishes with a very thin film of iron oxide which is not so fully oxidized as the red iron oxide caused by full oxygen exposure. This thinner film is also more dense and it tends to resist further corrosive attack. In water of with higher alkalinity, this oxide film becomes more stable and gives more protection to the steel. This is why your water treatment professional may have said to you that a little bit of rust color in your opened boiler is not necessarily a bad thing.

Maintaining a higher temperature feedwater supply also reduces the work the boiler has to do to produce steam. Increasing the feedwater temperature to 200 degrees or greater will save money in fuel costs and reducing the chances of oxygen pitting in the boiler. It will also help reduce the costs of boiler water treatment chemicals. To better understand your boiler system’s chemical requirements, it is best to consult your water treatment company.

An New Advancement in Boiler Water Treatment Has Become an Industry Game Changer

Until recently, providing a high pressure boiler with softened, nearly oxygen-free water was the benchmark and cornerstone of any comprehensive boiler water treatment program. However, new technologies in water treatment has reduced many of the complications associated with maintaining those standards. For instance, today many boiler systems can be treated with EcoSHIELD, a film-forming chemistry that virtually eliminated the need to remove oxygen or even soften the water. EcoSHIELD chemistry treats the metal surfaces of the boiler, NOT the boiler water. It bonds to steel surfaces at the molecular level and creates an impermeable protective layer between the boiler water and the metal. EcoSHIELD is so effective that it actually increases the heat transfer ratio in most boilers, which increases efficiency and reduces fuel costs, as well as decreases the instances of breakdowns and tube failures. A typical “side effect” of a boiler that is treated with EcoSHIELD is crystal clear boiler water.

Please note: The decision to use EcoSHIELD in a boiler should be made by an experienced water treatment professional. Every boiler is different, and there are many considerations that need to be assessed to determine the correct chemical program for each system. Regardless of the chemistry used, most steam boilers will benefit from the practice of operating with feed water that is at 200 degrees Fahrenheit or above.

If you would like most information regarding Clarity’s EcoSHIELD, please do not hesitate to call us.

If you would like to know more about the common issues and pitfalls associated with boiler maintenance, please download our free eBook: Ten Huge Mistakes Facilities Make in Boiler Operation and How to Avoid Them below.

As always, thanks for reading!

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