Written by webtechs

Common Cooling Tower Problems & Solutions

This article will help you understand Common Cooling Tower Problems & Solutions so you can better care for your commercial or industrial property. Good business starts with a good budget that includes keeping the overhead down. Part of every business is having a clean and comfortable place for customers and clients to do business in. Large commercial properties feature cooling towers and chillers that must work together to keep these spaces cool and comfortable during the hot parts of the year. It is important to know the common cooling tower problems & solutions to help keep your budget under control.

Cooling Tower Problems

Buildings that feature cooling towers must keep track of and control the four major types of water treatment issues. These are biological contamination, corrosion, fouling and scaling. All of these problems reduce the cooling tower’s ability to be as energy efficient as designed. This means they take more electricity to do the same job. This raises your overhead and makes the cost of doing business higher.

Biological Contamination – Cooling towers by nature are places that are hot and humid. Along with the common and plentiful nutrients that most water sources contain it is an ideal place for the growth of unwanted biological growth, such as bacteria. These contaminants aren’t good for people, and are worse for the efficiency of your cooling tower. This comes in the form of biofilm, which is a build up on the internal components of your cooling tower. Even very thin layers can reduce the thermal efficiency dramatically.

Corrosion – Cooling towers and chillers that leak can many times be attributed to cooling systems that are ignored. This can be especially prevalent in cooling towers that use closed loop systems. When the air, sodium, and other chemicals that are found in our water supplies are left unchecked to run through a cooling tower system they eat away at the metal and will lead to leaks.

Fouling – Fouling can occur at different areas of your cooling tower system. The fill is one of the prime locations for fouling to occur. Fouling is the clogging of cooling surfaces or pipes with debris, dirt, and dust. When water cannot make it into and pass through the fill as designed, the air is not cooled properly. This means that the system has to work longer to achieve the same results. Which means it is using more electricity.

Scaling – The primary role of cooling towers are to exchange heat from the chiller or industrial process. This means that build up of minerals in the water can create layers that rob efficiency. The different types of minerals, like calcium, that are part of the high heat system break down and are deposited on the cooling tower heat exchange surfaces. Scaling must be removed or operating costs will increase.

Cooling Tower Solutions

Every cooling tower’s set of problems will be different. The location’s water source, age of the cooling tower, and even the air being used to cool the water varies by location. This means cooling tower maintenance and water treatment is a progressive and customized undertaking. There is no “one size fits all” solution for cooling tower maintenance. Choosing a cooling tower maintenance company that helps control all 4 of the performance diminishing problems will help achieve lower operating costs.

Treating Biological Contamination

The first and last step after you have found that a cooling tower is contaminated with biological growth is to collect a water sample, and it is the last item of business too. Here we will look at  the overall order of how you should go about treating a cooling tower system of a biological contamination. The contamination is dangerous to the health of people in the building and near the site as the contaminants can cause respiratory infections. It is treated by shocking the system with chlorine over a series of 48 hours in various concentrations followed by a complete flush and refill with new water.

To prevent future contamination all leaks should be eliminated from the cooling water system. A sample is taken at the end of the cleaning procedure and sent for analysis.  If the test comes back positive for L. pneumohphila the chlorination of the water and sampling must be repeated. This is why companies should only hire experienced cooling tower maintenance companies so they avoid unnecessary downtime.

Preventing Corrosion

There are 3 ways that corrosion can be controlled, epoxy coatings, adding orthophosphate to the water treatment, or raising the pH of the water up close to 9.0.  A delicate balance of these approaches can help extend the life of your cooling tower and the individual components.  When the pH is too high cooling tower water cannot be treated as effectively with chlorine treatments that help control the biological contaminants. Orthophospahte does help prevent corrosion as well but it can act as a “fertilizer” for some types micrbiological species.  Quality chiller tube coatings and coatings for the cooling tower help protect the metal from carbon steel corrosion.

Treating Fouling

Fouling in cooling towers causes diminished cooling tower performance which leads to inflated energy consumption.  Fouling does this when debris or biological matter prevents the even distribution of water through the system in tubes, nozzles, fill, or other areas where water needs to have unimpeded movement. To treat fouling chlorine can be used, fill can be changed, and nozzles or other hardware can be swapped out for new parts to recover the performance the cooling tower was designed with.

Removing Scaling

Scaling is a thin coating of minerals or chemicals which insulates the tubes and prevents effective heat transfer, can increase back pressure, and also restric the unit’s generation. Calcium in the makeup water is the main issue that can lead to scaling and should be monitored and treated when necessary. Tube coatings which are made from polymers are one of the ways scaling is prevented. These coatings provide a surface which is conductive to heat to maintain performance but do not give calcium a place to stick to to build up. If there is significant scaling there are cleaning procedures which will remove the scaling, which is a perfect time to use chiller tube coatings to prevent scaling in the future.

4 Keys To Water Treatment

  • Make sure your system is consistently controlled for biofilms. It is easier and less expensive to keep it clean, than getting it cleaned.
  • Get your bleach fresh, keep it in the shade, and make sure you test it at every delivery.
  • Use tests which challenge your assumptions about the variables in your cooling tower with labs for verification and adjust accordingly
  • Constant monitoring is the only way to keep on top of your cooling tower scaling, corrosion, and biological growth. Monitor regularly!

Water treatment along with chiller & cooling tower maintenance that involves cleaning all of the heat exchange surfaces is the way to keep your commercial HVAC system operating properly.

Cooling Tower Maintenance & Repair

If you have a business or property that has cooling towers in the Phoenix metro area All Kote Lining, Inc. has the training, tools, and team you.  We understand how cooling towers function in the arid Arizona desert and how the makeup water affects the cooling towers and chillers. When you need cooling tower repair, maintenance, or chiller work All Kote can save you money and get the job done quickly. Give us a call today! 480-966-4446.

Written by webtechs

Chiller Maintenance

Centrifugal chillers of today offer some of the highest efficiencies ever. The technology may be more advanced, and the refrigerants are newer, but some things remain the same: the systems’ need for regular maintenance.

To help today’s high-efficiency chillers maintain those efficiencies in the field, their major components — tubes, oil, compressor, condenser, refrigerant, and starting equipment, to name a few — need to be inspected and maintained regularly.

Jeff Carpenter, marketing manager, Carrier Commercial Service (Syracuse, NY), said that the top areas that affect chiller efficiency are:

  • Tubes (“Make sure they are cleaned and maintained”);
  • Controls, which need regular inspection and calibration;
  • Refrigerant charge optimization; and
  • Regular oil changes and yearly oil analysis.

The most overlooked work, he said, is “taking normal, everyday and weekly readings.” If there are no operating problems, staff might ignore this simple task. Taking regular readings, however, allows them to watch for trends, possibly catching problems before they result in equipment damage and unexpected downtime.

This article provides an overview of regular chiller maintenance pointers provided by Carpenter and Carrier technical literature.

TUBE CLEANING, WATER CIRCUITS

The condition of local water will have a lot to do with the frequency required for tube cleaning and inspection, Carpenter said. Know your water quality. The frequency with which tube cleaning winds up being performed is determined mainly due to water conditions; it may also make you decide to upgrade your chiller’s water treatment system.

“Higher-than-normal condenser pressures, together with the inability to reach full refrigeration load, usually indicate dirty tubes or air in the chiller,” states Carrier. This is where taking daily measurements and tracking them over time really pays off. “If the refrigeration log indicates a rise above normal condenser pressures, check the condenser refrigerant temperature against the leaving condenser water temperature.”

If the reading is higher than design, the condenser tubes may be dirty, or water flow rates may be incorrect.

The first step is to inspect the heat exchanger tubes and flow devices. “Inspect and clean the cooler tubes at the end of the first operating season,” the company advises. “Because these tubes have internal ridges, a rotary-type tube-cleaning system is needed to fully clean the tubes.”

An inspection of the tubes’ condition will help you determine how often future cleaning will need to be done, and whether the system needs improved water treatment in the chilled-water/brine circuit. Look for signs of corrosion and scale. The chilled-water cooler tubes are usually part of a closed circuit and less susceptible to “dirty water.” Nevertheless, they should be inspected after the first season of operation.

While you’re there, inspect the entering and leaving chilled-water temperature sensors and flow devices for corrosion or scale. Remove scale if possible, but replace the sensor or Schrader fittings if they’re corroded.

“Keeping the condenser tubes clean is essential in maintaining peak performance,” Carpenter said. “On the condenser side, at a minimum we recommend yearly tube inspections.”

Cleaning can be done as required depending on the results of the inspections. The presence of scale or other corrosion may require chemical treatment or cleaning beyond just brushing the tubes. Inspect the entering and leaving condenser water sensors and flow devices for signs of corrosion or scale. Again, replace the sensor or Schrader fitting if corroded; remove any scale.

REFRIGERANT CHARGE

Proper refrigerant charge in the chiller is essential for optimal performance and energy efficiency, noted Carpenter. Too much refrigerant in the unit can cause refrigerant carryover, a condition where liquid refrigerant enters the compressor and evaporates. This could lead to reduced capacity, an overloaded motor condition, excess power consumption, and possible damage to the compressor impeller.

On the other hand, Carpenter pointed out, insufficient refrigerant charge can result in the top or uppermost layers of the cooler tube bundle not being submerged in liquid refrigerant. In this situation, the “lift” on the compressor increases, resulting in higher-than-normal power consumption. In undercharged units, add refrigerant to minimize power consumption.

Carrier recommends that service contractors trim the refrigerant charge to obtain optimal chiller performance. If it becomes necessary to adjust the refrigerant charge, the company says, “Operate the chiller at design load and then add or remove refrigerant slowly, until the difference between the leaving chilled-water temperature and the cooler refrigerant temperature reaches design conditions or becomes a minimum. Do not overcharge.”

The company says that refrigerant can be added through the storage tank or directly into the chiller, per the manufacturer’s procedures. Excess refrigerant should be removed by following the manufacturer’s recommended procedures.

STARTING EQUIPMENT

Often overlooked, but critical to precise operation, are control devices and the control system.

“While less obvious than the need for mechanical maintenance,” explains Carpenter, “servicing controls is just as important to the overall operation and efficiency of the chiller or chiller plant. And because the mechanical and electrical components were designed to work together, servicing your system in its entirety is the only way to ensure optimal performance and prevent serious problems.”

If the chiller is part of a central plant control or integrated into a building energy management system, Carpenter states, “It is good practice to perform regular system evaluations to ensure that performance is optimized. Trend reports can give you a complete picture of your chiller plant or entire building HVAC system. Armed with reliable information, specialists can suggest and make improvements that will enhance system operation and reduce operating costs.”

A chiller controls test is part of this regular evaluation. It “facilitates the proper operation and test of temperature sensors, pressure transducers, compressor guide vane operation, oil pump, water pumps, cooling tower control, and other on/off outputs,” says Carpenter. “Individual sensors can be calibrated on an as-needed basis or in regular intervals.”

Cleaning and examining the control contacts is another aspect of regular control service. During this part, it is less critical that proper safety procedures be followed. “Before working on any starter, shut off the chiller, open and tag all disconnects supplying power to the starter,” the company warns.

The company also warns that “The disconnect on the starter front panel does not de-energize all internal circuits. Open all internal and remote disconnects before servicing the starter. Never open isolating knife switches while equipment is operating. Electrical arcing can cause serious injury.”

First, inspect starter contact surfaces. Look for wear or pitting on mechanical-type starters. “Do not sandpaper or file silver-plated contacts,” the company states. Follow the starter manufacturer’s instructions.

Vacuum or blow off accumulated debris on the internal parts periodically with a high-velocity, low-pressure blower.

The company also notes, “Power connections on newly installed starters may relax and loosen after a month of operation. Turn the power off and retighten them.” Recheck them once a year; loose power connections can cause voltage spikes, overheating, malfunctioning, or failures, the company warns.

OIL, LUBRICATION SYSTEM

Changing the oil, of course, is critical to operation, perhaps more so than it is to efficiency; analyzing it once a year is equally important, said Carpenter. That determines the frequency of future oil changes, and may alert you to other problems in the system that can be addressed during planned maintenance rather than emergency downtime.

“Do an oil and filter change after the first year of operation,” Carpenter said, “then do a yearly oil analysis. If that’s clear, you can go do an oil change, in some cases, up to every five years.” If the oil is dirty, of course, it needs to be changed more often. Particle size can indicate if it’s from a compressor wear problem or normal wear and tear. Regardless, “Change the oil filter on a yearly basis,” the company states, “or when the chiller is opened for repairs.” The refrigerant filter-drier should be changed “once a year or more often if its condition indicates a need for more frequent replacement,” the company says.

The lubrication system should be checked every week, the company says. “Mark the oil level on the reservoir sight glass; observe the level each week while the chiller is shut down.”

If the level goes below the lower sight glass, make sure the oil reclaim system is operating properly. If more oil is required, add it through the oil drain charging valve. “A pump is required when adding oil against refrigerant pressure.” Note the amount and date that any oil is added.

Note: “Any oil that is added due to oil loss that is not related to service will eventually return to the sump,” the company points out. The oil must be removed from the sump when it reaches a high enough level.

STILL MORE TO IT

Chiller maintenance includes many other areas, such as checking for refrigerant leaks and inspecting power transducers. The point is to be regular, and to check the system’s vital signs (temperatures and pressures) daily.

Maintaining the compressor, Carpenter says, is critical to proper operation and overall equipment reliability, minimizing downtime and maximizing uptime; however, it may not be directly related to the big efficiency picture.

To inspect the bearings, the company says, a complete compressor teardown is required. Only a trained service tech should remove and examine the bearings.

Bearings and gears should be examined on a regular, scheduled basis for signs of wear. Gear inspections require a complete compressor teardown. They, too, should only be done by trained technicians. How often? That is determined by the hours of chiller operation, load conditions during operation, and the condition of the oil and lubrication system.

Excessive bearing wear can sometimes be detected through increased vibration or increased bearing temperature.

One problem is, many companies don’t have enough staff available to take daily readings. Carpenter says that’s where a service like Carrier’s National Monitoring Center can help, by monitoring remotely and alerting onsite staff to potential problems. “It speeds up the whole service process,” he says.

Companies that invest in a new, high-efficiency chiller deserve to get their money’s worth. By performing regular maintenance and taking daily readings, you can help ensure that the chiller fulfills its promise.

Phoenix Chiller Maintenance

There is a lot of work that goes into maintaining chillers and it takes training, the right tools and time to get it done right. All Kote Lining, Inc. specializes in chiller maintenance, cooling tower maintenance, and epoxy coatings that preserve metal, fiberglass, concrete, and more.  Chillers need regular maintenance to get the most cooling with the least electricity.  Let us help you keep your chillers running efficiently and make them last longer. Call All Kote at 480-966-4446.

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Written by webtechs

Cooling Tower Corrosion Protection

 

If you are searching for “Cooling Tower Corrosion Protection” you are probably trying to understand the ways you can make your cooling tower system last longer for your commercial or industrial property.  This article is designed to help you understand why cooling towers are especially prone to corrosion, and what you can do to about it.

Cooling towers are a vital part of a lot of businesses and industrial processes. They provide cooling for chiller systems and help remove heat from fabrication processes.  Coolant in many applications comes in the form of water, and when combined with extreme heat it creates an environment that is prone to corroding metal.  To extend the life of cooling towers, and their components, coatings are applied to various elements as a barrier between water and chemicals and bare metal.

What is corrosion?

Corrosion is a set of forces which have a natural tendency to electrolytically or chemically react with metals, when given the proper circumstances and opportunity. The most prevalent and common of these forces is Oxygen. With oxygen being the most common element on the planet oxidation is a serious concern for metal.  Oxidation is a reference to the way oxygen interacts with various compounds or elements and the term rust describes the way that oxygen interacts with iron. Iron is the basic ingredient used in the production of carbon steel which is very common in cooling tower components.

Regional Effects on Corrosion

The degree of oxidation and corrosion on carbon steel varies by degree based on the heat and humidity of a given geographical region. Places which are cool and dry haven’t the same predisposition for corrosion as somewhere that is humid and hot. It is in these hot or humid areas which corrosion must be prepared for prevented.

Atmospheric Effects on Corrosion

Today’s air conditions include an ever increasing corrosion atmosphere which is caused by considerable increases in industrialization.  The coatings that we used years ago which would be considered rudimentary by today’s standards functioned adequately with air that was more “fresh”.  With air quality changing and usually towards a higher content of gaseous byproducts ongoing research and development is necessary to keep the coatings used to prevent corrosion effective.

Cooling Tower Conditions and Corrosion

The purpose of a cooling tower is to take hot water from industrial or HVAC processes which produce hot water and cool it back down to be used again to sustain the process. As we know the combination of heat and humidity is the perfect conditions for corrosion to occur. In addition to heat and humidity cooling towers also include evaporation which causes an relentless flow of flow against the metal components in the cooling tower. When water stagnates around steel it actually develops a protective layer of oxidation which prevents aggressive corrosion. In the case of cooling towers the constant flow of air, water, and evaporation continually dissolves this film and perpetually eats away at new metal material.

Quality Cooling Tower Coatings

To help prevent corrosion and the need to replace components or entire cooling towers which are susceptible to corrosion coatings such as Belzona 1321 are used to centrifugal pumps, vacuum pumps, valves, heat exchangers, impellers, pipes, nozzles, water boxes, and much more. Benefits of using a coating like Belzona is that it makes maintenance more simple, cuts down on the need for spare parts, helps protect against corrosion, and therefore extends the life of cooling towers and chillers. Let All Kote Lining take care of your cooling towers the right way.  We specialize in maintaining the equipment you have to make it operate more efficiently and last longer.

It can be applied to various elements in the cooling tower system by using shimming, bonding, injecting and more application methods. It bonds aggressively to a wide range of substrates and as a multipurpose polymeric coating it does not corrode and provides exceptional resistance against a wide range of chemicals. If you have questions about how to prevent corrosion in cooling towers or would like to schedule cooling tower corrosion protection please call 480-966-4446.

Written by webtechs

Chiller Maintenance: Common Problems & Repairs

 

Chillers are usually the largest energy consuming element in most office building and industrial facilities. In fact in a lot of situations the chiller is responsible for over 50% of the electricity consumption. Being the largest energy user in your operation addressing and repairing common problems can mean big savings in utility costs.

In our homes we rarely look at our heating or air conditioning units until the simply are not working, and it seems a lot of commercial and industrial properties wait for something to fail as well. Chillers that are either maintained inefficiently or not correctly mean higher energy use, higher bills, and reduced equipment life.

5 Common Chiller Efficiency Killers

While there are more than just 5 reasons chillers could be having efficiency issues there are 5 that come up more often than others. These efficiency killers are: deficient operating practices, deferred or ignored maintenance, oversizing, ignoring cooling tower maintenance, and ignoring alternative-fuel chillers. Each of these different issues can mean very real and significant diminished chiller performance yet can be prevented and corrected with proper maintenance and repairs.

Deficient Operating Practices

When chillers operating practices are not up to par it means reduced efficiency, greater energy use, and ultimately reduced chiller life. This occurs in two basic scenarios, when a chiller is forced to go beyond its design specifications, or through the actions of untrained operators.

A very common situation in chillers is when more coolant is needed and the flow rate is simply increased past the manufacturers specifications.  While the belief is that if more water is going through the chiller more cold water will come out. This is actually the opposite of how chillers function and will limit the efficiency of the chiller. In fact running a higher flow rate than designed causes erosion in tubes and leads to them failing earlier.

Deferred or Ignored Maintenance

Everything in your building needs to be maintained properly to keep your business running properly and keep operating costs down, yet there are few systems that need more attention than your chillers.

When maintenance is deferred to avoid regular system shutdowns or isn’t even thought of chillers require more and more energy to do their jobs, costing operators more and more on utility bills. Poorly maintained chillers use as much as 20-25% more energy to do the same job. This means literally thousands of dollars difference which is much higher cost than simply maintaining your equipment.

Chiller Corrosion & Solutions

The majority of chiller tubes are made from copper and are prone to galvanic corrosion. The loss of carbon steel and corrosion can significantly affect the performance of you chiller caused by poor water flow problems and sediment buildup. Left to fester these issues means coolant loss from tube perforation. To resolve and prevent corrosion in chiller tubes chiller maintenance companies remove debris, sediment, and corrosion. Then the tubes are coated with high quality chemically resistant epoxy coatings. These coatings help prevent sediment from sticking and cover the copper and steel to keep corrosion from forming. Regular coating is critical over the course of your chiller’s lifespan and will not only extend the life of your unit, but it will run more efficiently and save a tremendous amount of energy.

Written by webtechs

The Importance of Drift Eliminators

 

This article covers “The Importance of Drift Eliminators“.  Understanding the components that make your cooling tower work helps understand the required maintenance. Regular cooling tower maintenance cuts down on wasted water, energy usage, and extends the life of your equipment.  Cooling Towers are complex devices that utilize many various components to achieve their cooling functionality. From Fills and nozzles there is a symphony of parts being played out as the natural process of evaporation is synthesized. The process of evaporation synthesis takes a ‘team effort’ so making sure all of your components work in concert is key to getting the most out of you towers. One of the vital components of cooling towers is the drift eliminator. This entry is going to briefly profile the drift eliminator in order to give more clarity to the picture of cooling tower functionality.

What Are Drift Eliminators?

Drift eliminators greatly reduce water loss in cooling towers by minimizing the ability for water droplets to get caught up in the air being discharged from the cooling tower. They achieve this reduction in water loss by producing directional change to the air flow throughout the tower to interrupt the upward motion of the water droplets. Water is fundamental to the functioning of a cooling tower reducing water loss can turn into great savings. Making sure you have high quality drift eliminators installed will set your cooling tower up for long lasting and efficient service and set you up for major savings over an extended period of time.

Every cooling tower loses a portion of water through evaporation into the environment during operation. Generally when cooling towers are working properly this loss is in the form of water vapor which is pure and poses no harm to the environment. In contrast loss that has mineral and chemicals from the cooling tower is drift. This undesirable loss of water is sometimes caused by the fast moving air carrying it out of the cooling tower. Treated water which is common in cooling towers can in fact pose a negative impact on the surrounding environment.

How Drift Eliminators Work

Drift eliminators are designed to prevent large water droplets from escaping via the cooling tower air stream.  They do this by forcing the droplets caught in the stream of air to causing a change in direction which reduces their velocity. They are directed into the blade walls and run back down into the tower.  When drift eliminators are properly installed and maintained they prevent the treated water from escaping the cooling tower. This saves operators money on treating additional water and helps mitigate damage to the environment. The best drive eliminators keep drive losses under .001%.

Professional Drift Eliminator Maintenance

Cooling Towers can be massive and keeping them running at a high level of efficiency takes a lot of work and maintenance. That amount of maintenance that is needed can actually be quite intimidating if you aren’t approaching it from a place of knowledge and understanding of your tower’s maintenance needs and how it is supposed to work. Having all of your components well maintained and in like new condition will allow you and your facility to enjoy the effects of a properly functioning cooling tower for years and possibly decades to come. If you have a cooling tower in Arizona and you have experienced excessive loss through drift, or you just want to have your cooling tower tuned up, please call All Kote Lining, Inc. at 480-966-4446.

Written by webtechs

Managing Concrete Cooling Tower Basin Leaks

 

Cooling towers function by utilizing coolant fluids which must be retained and recycled through the system. This is true for both mechanical and natural draft cooling tower technologies. A lot of people think of concrete as the superman of building materials which is just impervious, which is not true.  Concrete is chemically more similar to ceramic materials in terms of chemistry.  Ceramic products such as fired pottery or dishware are considered “vitreous” materials. Whereas concrete is a sub-vitreous construction material which is more porous which allows a degree of water permeability. Being a bit like a hard sponge the dried capillaries of concrete contribute to concrete’s permeability. Concrete cooling tower basin repair extends the life of the cooling tower and keeps operating costs more affordable.

Water Retention in Reinforced Concrete

When concrete elements are initially installed the design and concrete consistency play a major role in the long term durability of your concrete cooling tower water basin. When leaks are found or concrete is experiencing degradation concrete epoxy coatings can be applied to cooling tower water basins to help protect the concrete and extend the life of the cooling tower.

  • The concrete basins in cooling towers should include the following details which will help manage issues with water retention and durability.
  • Cement should be ordered with low water-to-cement ratios. This means that as the concrete dries there will be less shrinkage due to water evaporation.
  • Conform to ACI-350 standards for embedded reinforced steel which will help restrain cracking from material volume shrinkage.
  • Utilize formwork systems which do not include full wall section thicknesses.
  • Minimize the quantity of construction joints or proposed joins involved in the formed edges of the basin.
  • Institute a quality assurance and quality control phase in your concrete construction project.

Concrete Cooling Tower Water Basin Defects

Significant factors that lead leaks in concrete water basins in cooling towers are:

  • Misplaced steel bars inside the concrete mass which fail to control volume shrinkage.
  • Unconsolidated concrete which was not poured right and provides a direct conduit through the concrete.
  • Inadequately sealed concrete which leads to the corrosion or the embedded steel.
  • Absences or misplacement of water stop glands which prevent water from passing through expansion joints.

Leak Mitigation in Cooling Tower Basins

A lot of times cooling tower owners think that waterproofing is a one and done deal when the cooling tower is first constructed. There are both positive and negative side waterproofing measures which help prevent leaks and protect concrete. Positive side generally includes the waterproofing measures which are done before the cooling tower has been placed in service. Negative side waterproofing usually refers to coatings and repairs which are done after the cooling tower is in use or even when it is on-line.

Concrete Cooling Tower Basin Repair

There are different approaches for the repair of concrete cooling tower water basins. The appropriate repair will depend on the size of the leak and the amount of water leaking from your cooling tower. These repair approaches include:

  • Coatings
  • Grouting
  • Flow rerouting
  • Surface & Joint Seals
  • Membranes

Coatings

Epoxy coatings are a common and effective method for repairing concrete in cooling towers. The application involves the epoxy coating being bonded to the concrete surfaces of the cooling tower after proper cleaning and preparation. Specially designed epoxy coatings are used for these environment which are designed to cope with the constant presence of the chemicals used in cooling tower water programs.

Grouting

Grouting, much like we imagine in tile installation, involves injecting water-stopping materials around or behind structures which forms a barrier for process fluids and water. Generally these materials solidify to be anywhere from completely rigid to semi-gelatinous. This means that depending on the size of the gap or crack grouting can be flexible to follow expansion or rock solid to provide added structural rigidity.

Flow Rerouting

In emergency situations when there is heavy flow using re-circulating pumps or sand-bags.  This is due during monsoon conditions or when process fluid surges crest. In a lot of cases the leakage cannot be stopped until the pressures are lowered after bypass piping is installed into the joints or cracks in concrete members.

Surface & Joint Seals

Surfaces that experience cracking or joints that aren’t holding water can be repaired by installing materials over or in these areas. The materials used are highly specific to this application and must abe able to transmit and absorb loads and energy. This includes any flow or movement during the operation of the cooling tower.

Membranes

Membranes are typically part of positive side concrete cooling tower basin waterproofing as they require a very high level of quality assurance. These systems can be both unbounded and bonded sheet systems that feature welded seams designed to contain the process water.

Concrete Cooling Tower Basin Repair

All Kote Lining Inc. offers service valleywide in Phoenix, AZ. We specialize in the evaluation of cooling tower maintenance including the repair of concrete cooling tower basins. From the nozzles, through the system, and back to the basin we can maintain, repair, and replace any element on your cooling tower to refurbish your cooling tower and extend its working lifespan.  Properly servicing and repairing your cooling tower will save companies from inflated operating costs from having to prematurely replace cooling tower systems.

For more information about how we can help repair and extend the life of your cooling towers:
Call All Kote Lining, Inc at 480-966-4446.

Written by webtechs

How Do Chillers work?

 

When you are searching “How Do Chillers Work?“you are likely learning how vapor-compression chiller’s work. How cooling towers work, or what a refrigerant cycle is? Keep reading to find out how these systems work.

Chillers use one of two methods, an absorption refrigerant cycle or a vapor-compression for cooling fluids for the heat transfer. Each type depends on three basic principles to work.

  1. Liquid gets heated and vaporized, creating a gas. As gas is cooled, it is condensed to a liquid.
  2. By decreasing pressure of a liquid lowers the boiling point, while increasing the pressure raises the boiling point.
  3. Heat will flow hot to cold, always.

Basic Cooling Cycle

Both absorption chillers and vapor-compression have the same basic cooling cycle’s. They use liquid refrigerant which changes stages to gas inside an evaporator that absorbs the heat from water, which then gets cooled.

Refrigerant gas gets compressed with higher amounts of pressure by a generator or compressor, then converts back to its liquid state as heat is rejected through the condenser, expanding a lower pressure combination of liquid and vapors which then ends up back in an evaporator section. This starts the cycles over.

Vapor Compressor Chiller

Consisting of four main components, a vapor compression chiller uses a vapor compression refrigeration cycle. These components include the evaporator, compressor, metering device, and condenser.

Usually, vapor compression chillers will use either CFC or HCFC refrigerants to get the refrigeration effect. The force that drives a vapor compression chiller is the compressors, which acts like a refrigerant pump.

The compressor sends compressed refrigerant gases to the condenser which then rejects any heat energy to the air outside or cooling water of the system.

The heat transfer provides the needed refrigerant gas for condensing a liquid that gets sent to the metering device.

The liquid refrigerant flow is restricted by the metering device, which results in a pressure drop. This drop causes a change in warm refrigerant liquid so that it creates a gas which absorbs heat out of the water that is then cooled because of adiabatic flash evaporation.

Metering devices are placed so expanding refrigerant gases are contained inside the evaporator, which transfers heat energy between the water that needs to be cooled and into a refrigerant gas. The warmed refrigerant gas then goes back into the compressor to begin the whole cycle over, with the recently chilled water being in a separate loop and used for the cooling process.

Absorption Chiller

A heat source is used by an absorption chiller to drive refrigeration cycles in the place of mechanical compressors. Two fluids are used for the absorption chillers, including a refrigerant that is often water, and an absorbent which is often ammonia or a lithium bromide mixture.

The absorption cycle separates and recombines these liquids, where the lower pressures allow the water to change phases easier than usual, with a high affinity of the liquids promoting easier absorption.

This cycle starts with a combination of liquid absorbent and refrigerant water which gets heated at higher pressures, boiling water from the solution. Then, the vapor from the refrigerant water gets sent to the condenser coil, heat is rejected and condensed to a high pressure liquid. This liquid then gets put through the lower pressure evaporator using the method of adiabatic flash evaporation to convert it back into a gas, which absorbs heat from the water which is to be cooled. The liquid absorbent is now concentrated in the generator, and gets recombined with a lower pressure refrigerant vapor that is returned by the evaporator, and the cycle starts over.

Cooling Towers

Heat energy which was absorbed by the chiller process then needs to be rejected from the system, back into the atmosphere. Usually, cooling towers are used for lowering water temperatures within a larger chiller system, also known as evaporative heat rejection devices.

Phoenix Valley Chiller Maintenance

Chiller Maintenance keeps equipment in good condition, operating more efficiently, and saves money by using less energy. All Kote Lining, Inc. offers chiller maintenance and repair to the Phoenix Valley. We keep chillers and cooling towers operating at their highest possible performance. Refurbishment is one of our services which saves companies and municipalities significant operating costs in comparison to needing cooling tower or chiller replacement. Get in touch with All Kote Lining, Inc. to learn more about what we can do for your chillers and cooling towers.

Call 480-966-4446 Today!

Written by webtechs

Waterproofing Concrete Water Tanks

 

Water reservoirs, damns, wastewater treatment plants, and drinking water facilities are vital to the public works of communities. When the concrete is in bad condition and water leaks it can mean that the structure allows contaminants out of or into the storage.  The contaminants can ruin water supplies and significantly impact communities.

Leaks & Contamination

Municipal or private water supplies can be contaminated through the migration of waterborne chemicals. When wastewater structures leak it can impact the environment and are especially hard to find if they are in the base of the concrete structure. With drought being a reality in so many areas of the world even small losses of drinking or agricultural water have a meaningful impact.  When any kind of water storage container needs extensive repair it means disruption to the community through downtime and expense.

Cracks & Service Interruption

Just about every concrete structure cracks due to settling, curing, seismic activity, shrinkage, or a number of other factors.  When it comes to concrete water tanks any cracking can lead to leaks and contamination.  These are the two most common factors of having downtime in operations that rely on concrete water holding structures, like wastewater or cooling towers.

Crack Prevention

Preventing cracks is clearly a priority for all operations that include water storage.  Preventing cracks and leaks comes in various waterproofing forms.  Here are few of the options on the market today:

  • Installing a coating of liquid membrane by spraying or rolling which leaves a dry yet rubberized waterproof layer. The rubberized nature of these coatings helps the layer be flexible and compensate for cracks.
  • Layered felt and asphalt which are built up into layers which creates a physical waterproof barrier.
  • Membranes of self-adhering rubberized asphalt that make a barrier.
  • Integral crystalline waterproofing can also be used to fill the spaces between parties of concrete.
  • Cementitious waterproofing products brush applied to the concrete and can be mixed with optional additives which increase durability.
  • Installing a sodium bentonite layer on the outside of the tank will absorb water and expanding to fill in the voids and cracks. When it fully expands it remains in the cracks to avoid additional water intrusion.

Choosing a Tank Waterproofing Option

There are a lot of products and companies offering water tank coating, how do you choose the best option for your system?  These are some of the factors that you should consider as you make decisions for your property and water storage or containment.

System Safety

Choose waterproofing coatings which are safe for the environment and are non-toxic.  When the project involves storing drinking water is especially important to choose a system which will not deposit chemicals or debris into the water.

Cost Of The System

How much the system will cost in terms of raw materials and labor hours should be weighed against the lifespan expected from each product.  Waterproofing coatings which take longer to apply will generally be more costly.

Time To Install

When you are dealing with a complex construction project or you are planning downtime for a system that a building or community relies on you need to know how long it will take to install.  Physical barriers like rubber and felt are time intensive and will require longer install times that could mean increased interruption in service.

Waterproofing Life Span

Knowing the expected life span of the waterproofing solution should play into your decision making.  Some products are designed to be permanent solutions while others have a finite life span.  Other systems eventually dry out, crack, are easily damaged, and will eventually leak and cause contamination.  Weight out how long the solution will last against the cost and service interruption.

System Flexibility

Does the system have a required installation time?  Some systems must be installed either before, during, or after the concrete is poured to create the structure.  Some systems mean having to keep the area around the water tank clear so maintenance can be done on the exterior of the water storage tank.

Heat Compatibility

Some water containment systems require the ability to withstand heated water such as in cooling tower water basins.  The heat involved in cooling tower applications must considered when choosing an option for concrete waterproofing.

Chemical Resistance

Many water storage systems like wastewater, drinking water, or the water used in cooling towers carries with it chemicals that can deteriorate concrete.  Coatings must be used which can cope with the chemicals used to treat these different types of water.

Warranty or Guarantee

When you are weighing your options for which concrete water tank waterproofing contractor or product to use you should weight the warranties or guarantee. It’s important to choose tank maintenance companies and products that warranty their work and products.

Conclusion

Ultimately each installation is different as the operations, environment, age, and condition of every tank is different. Take the time to discuss your options for your local contractor for waterproofing concrete water tanks.  Have representatives come and assess the condition of the your water tank, recommend the best solution or solutions, and then choose the one that fits your needs best.  What is best will depend on how long the system should last, if and how disruptive downtime is to the community.

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