Jun 9, 2017

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Cooling Tower Concrete Repair Phoenix

Categories:
09/06/2017

 

Even with the best mix and pour concrete deteriorates over time. Reinforced concrete structures require continual maintenance and inspection. This helps find and repair small issues before they compromise the entire structure. Structural elements of the cooling towers are many times made of concrete. Concrete can comprise the foundation, housing for mechanical elements, and even be the liquid containment area. Deterioration occurs in both mechanical draft and natural draft technologies. How quickly the deterioration occurs in these aggressive environments is dependent on regular maintenance. It is also affected by the consistency of the processes. If the processes shift drastically, it can also reduce cooling tower concrete life. This is based on the assumption that the cooling tower’s concrete elements were constructed using the best practices.

Unfortunately for the end user and responsible party for maintaining cooling towers the quality of initial construction plays a very large role in the lifespan of the cooling tower. In addition exposure to unusually harsh chemicals or environmental exposure can accelerate deterioration. Which can lead to structural failures and complete rebuilds or replacements. A quality assessment of the structure will help understand any deficiencies in the structure. Along with an understanding of the cooling tower’s individual environmental load from weather and chemical exposure can help develop deterioration trends. Knowing the current condition and the projected deterioration schedule helps owners project their maintenance costs and cooling tower costs over longer periods of time.

Adequate preparation for the future is the key to successful business. For private companies or public municipalities it is critical to have a plan in place to prepare for all costs. Proper evaluation, investigation, and planning will help understand and plan for the life-cycles of cooling towers. Many owners and civil divisions use an LQQ method for understanding and planning for their assets. This can simplify and make planning maintenance much easier and more effective. An LQQ system means Locating, Qualifying, and Quantifying the condition of the concrete structure. Once the root-cause issues are identified planning can be made to regularly maintain and extend the serviceable life of the concrete cooling tower. This makes the budgeting for these eventualities realistic and avoids surprise maintenance issues that can be fairly costly.

Original Cooling Tower Construction
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The costs of conducting effective quality control and quality assurance during the construction phase of concrete cooling tower elements is absolutely critical to the lifespan of the cooling tower. Documentation can be made during the construction phase, yet without visually inspecting during the actual construction there is little assurance that it is being done correctly. The ways that construction mistakes or failures can manifest are varied. Here’s a list of common issues during cooling tower construction.

  • Ignoring manufacturer recommendations with regard to construction and application methods.
  • Failure to accurately follow the original construction documents.
  • Substitution of inferior materials.
  • Inaccurate or inappropriate materials specified for construction.
  • Substandard construction documentation
  • Damage or abuse to the structure during the original construction process.
  • Inferior craftsmanship during construction.

Unfortunately many of the defects in the construction process manifest themselves in obvious visual failure until after negotiated warranty periods. This leaves owners or municipalities stuck having to maintain inferior concrete. Maintenance that is far more involved and costly that what is normal wear and tear on the concrete elements of cooling towers. Incorporating the walk through lists that are carefully followed by qualified construction professionals during the concrete construction phase is fundamental in catching and addressing original construction problems.

Simply seeing and fixing a problem area in the concrete isn’t a total repair solution. Owners need to ask for and get root-cause assessments that point to the root reason the concrete is failing or deteriorating more quickly. This will point out a potential quality and longer lasting repair solution. This avoids putting a series of “band aid” repairs on top of each other.

Planning Scheduled Cooling Tower Maintenance
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Even if the cooling tower’s concrete is built to specifications everything degrades over time. When a cooling tower in installed a plan should be put in place for the inspection and regular maintenance. This makes predicting expenses easier. It also ensures that the inspections, preventative maintenance and repairs are actually carried out. Many times downtime for the cooling tower is limited and maintenance must be done quickly. During these downtimes deterioration may be noted but not acted upon. These reports are critical in preparation for following scheduled maintenance. Extra time should be scheduled for the repair of any problem areas. The type of damage or issues that might be noted regarding the reinforced concrete structure might include;

  • Joint sealant failures
  • Wall or base slab cracks that leak water
  • Deterioration and/or leaking from expansion joints
  • Mechanical penetration leakage
  • Deficient foundation support for the cooling tower
  • Corrosion of the anchor bolts
  • Spalling or corrosion of embedded concrete rebar
  • Vegetation or algal growth in the cooling tower
  • Deterioration of surface paste or coatings

Each cooling tower structure poses unique obstacles for cooling tower repair contractors. An engineered solution is a must to address each of the issues fully. This is true for both minor and major structural issues. Whether the problem is a crack, foundational stabilization issue, deteriorated containment liner, or halting cooling tower water egress a proper repair strategy should include the following.

  1. Inspect and identify the root cause
  2. Use the right techniques and raw materials in repair
  3. Employ a quality control program for the repairs
  4. Hire only qualified and experienced cooling tower repair contractors

Assessing Concrete Deterioration
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During the regularly scheduled maintenance it is the responsibility of cooling tower crews to watch for, note, and report any deteriorated sections of the cooling tower. If issues are found a structured assessment should be done. The approach for that evaluation should follow this pattern.

  • Find the deteriorated area
  • Determine the root cause and affected elements
  • Determine what repairs are needed
  • Weigh repair vs. replacement for these repairs

One the damage or deterioration is accurately assessed, a detailed and through repair plan be developed. This plan will include variables relevant to each cooling tower’s particular operating environment. It will take into account all of the variables that affect the cooling tower and its concrete. The chemical, construction material, and thermodynamic variables that affect cooling towers should be addressed specifically. This approach should produce a longer lasting repair plan that will increase the serviceable lifespan of the cooling tower.


Quality Cooling Tower Concrete Inspection & Repair
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If your cooling tower concrete is showing signs of failure, or if you want to develop a quality maintenance plan All Kote can help. Having a accurate idea of the condition of your cooling tower concrete elements helps with budgeting and avoids unnecessary surprise costs. Call All Kote today to get your appointment scheduled at 480-966-4446.

Freezing Weather Cooling Tower Maintenance

Categories:
09/06/2017
Freezing-Weather-Cooling-Tower-Maintenance-Arizona

 

With the cooler months on the way the potential for freezing temperatures looms. While it isn’t very many days a year that Phoenix gets freezing temperatures it is important to know how to cope with it. This guide helps understand freezing weather cooling tower maintenance. Particular attention should be given to counterflow towers because it takes unique procedures to cut down the ice formation when it is running in below freezing temperatures.

Basics Of Freezing Conditions

The first and most important step is to understand each cooling tower’s needs in a given location and under various levels of use. The absolute best method is frequent visual inspections to get a baseline for each of the different operating conditions. Then you can predict the procedures that work for your given circumstances and your cooling tower.

Preheating the water in the basin is the key to successful winter start up and should be done before the water is directed up and over the tower. The industrial heat load must be applied to the tower with all of the return water being bypassed into the basin. After the water has reached about 80°F you can then stop the bypass and run the water through the cooling tower itself. Then the quantity of fans and their speed can be used to regulate the temperature of the water in the basin. If the temperature is low enough the fans might well all be turned off to maintain the temperature of the water in the basin.

During these colder operating conditions the thermal draft upward can be sufficient flow to keep the fans off or even at very low speeds. This system may well become an alternative to cold weather operation given the colder operating conditions.

Controlling Ice Buildup

Ice buildup can add weight and damage the cooling tower, concrete, and the fill. Ice that builds up on the lateral supports and columns should not be manually broken off as it is possible to damage the structure. The best method to removing the ice in these conditions is to utilize the heat from the industrial process to melt the ice. Fans should be slowed or even turned off to clear the supports of ice.

Extreme Weather Procedures

For some parts of Arizona below zero conditions do occur. In this conditions the standard procedure is to operate each of the individual fans in reverse every two to three hours. The period of time they are ran in reverse should not exceed 20 minutes.

Deicing control systems should be simple and follow a logical progression of events. It should look something like the following: The primary deicing switch would switch a group of fans to start slowing down, come to a stop, and shift into reverse. Having the ability to control individual groups of fans gives the flexibility to run extra deicing procedures on areas that are more prone to icing from direct wind or snow drift. The fans deicing cycle should not run longer than 30 minutes to prevent ice forming on fan stacks, fan blades, or drift eliminators.

Cooling tower operators should keep log books that record all of the data needed to develop an effective deicing strategy for your cooling tower. This log should include weather conditions, how many pumps are operating, individual fan speeds, and number of fans operating.


Regular Cooling Tower Inspection & Maintenance

The key to knowing what your cooling tower’s condition is, and what steps to take to fix it relies completely on regular inspection, repair and maintenance. This not only helps keep your cooling tower energy efficient but it ensures that all of the parts are ready for more extreme changes in weather conditions and either hotter or colder weather conditions. Don’t let them fall into neglect and end up failing you when you have work to do. Get your cooling towers maintained, repaired, or refurbished by All Kote Inc.

How A Chiller Works

Categories:
09/06/2017
How-A-Chiller-Works-Phoenix-AZ

 

Industrial chillers are used in large commercial or industrial buildings. They are much more efficient at cooling these large spaces and work by using a de-humidification or vapor compression technology. How a chiller works is fairly complicated but we will examine is a bit more closely in this post.

How Industrial Chillers Keep It Cool

Vapor back to liquid

When operating correctly the condenser has a twofold role in the industrial chiller. The first step in a chiller is taking superheated vapor and reducing it back to liquid coolant. This process mush transfer enough head from the refrigerant to lower its temperature to convert it back into a liquid form. Once this is done the condensation may begin. The quality of the refrigerant continues to improve as the heat is transferred out of the water, or refrigerant. This process continues until the air has been completely transferred back into liquid. In a perfect world this process is complete by the time the coolant reaches the outlet of the condenser. However to prevent pressure losses and liquid flashing subcooling helps prevent issues with introducing vapor back into the system.

Cooling the hot liquid refrigerant

Even after the condensation process the refrigerant is still at a high temperature and needs to be cooled before it can be reused as a heat transfer medium. In chillers this is done by decreasing the pressure. Physics dictate that if the pressure is reduced in a space that the temperature will follow. So you can count on the temperature to follow if you reduce the pressure.

Temperature Reduction Through Lowering Pressure

To do this in the chiller restriction is a necessary part of reducing the pressure. System loads vary based on a few different elements so the system cannot regulate this depressurization process. The thermostatic expansion valve is responsible for lowering the pressure in the tanks holding the refrigerant that needs to be cooled. This is an adjustable pressure regulator that can adjust for the load of the chiller. The thermostatic expansion valve will not maintain the constant vapor pressure and is only a superheat controller. It simply provides the reduction in pressure necessary to a designated level which is determined by size load, system conditions, load demand, the compressor size, and the thermostatic expansion valve. Some systems require constant evaporator temperature. In these cases a pressure regulating valve should be added to the system. This will help maintain the pressure corresponding the saturation level.

Pressure Regulation

Pressure loss in the thermostatic value can be explained by the mixture of both states of refrigerant. Meaning that when both the liquid and vapor exist in a section of the cooling system superheating or subcooling cannot be achieved. The saturation temperature will always be directly linked to the pressure.

To remove the necessary heat some of the liquid refrigerant must be boiled. This is another process that results in lower liquid temperatures. When the chiller is working properly and subcooling is achieved the difference between the cooled refrigerant introduced into the system will increase the efficiency due to the energy decreased by the boiling of the refrigerant.

Complete Vaporization

The evaporator tubing is the final leg of the refrigerants journey through the cooling system. At this point it is a mixture of both vapor and liquid. Heat is applied to the tubing by having warm air blown over it. This process boils off the last of the liquid leaving only vapor. The last molecule of liquid should be converted to vapor at the evaporator outlet. This means that the vapor at the inlet of the compressor is sufficiently saturated.

This process continues until the space that needs cooling is at the desired temperature. Then the equipment cycles off and waits for a need for it to come back on.

 


Chiller Maintenance & Repair Phoenix AZ

If you have a commercial property that uses a chiller to keep the building cool you need to make sure that you are getting regular maintenance. This will help prevent repairs and promote better energy efficiency. If there are already problems we repair chillers and can provide coatings to help prevent corrosion of chiller tubes. Give us a call and find out what we can do for your chiller in the Phoenix areas. Call today at 480-966-4446.

How FRP Linings Are Applied To Steel Tanks

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09/06/2017
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There are two methods by which FRP tank lining systems can be applied. There is hand lay-up and spray-up methods to install the FRP lining. Before either type of coating can be applied sand blasting has to be done to remove any debris or corrosion. This provides a clean and rough surface for the primer to be applied on. Adhesion of either system is dependent upon having that rough and primed surface.

Spray-Up Method

Glass-chopper guns are used to apply the spray-up FRP linings. The glass-chopper gun mixes to glass roving and resin components at the time of being sprayed. Dual head glass-chopper guns allow very rapid rates of depositing the coating. The average thickness of the resin at the tank bottoms are typically a quarter inch when the spray-up method is used.

Hand Lay-Up Method

While the spray-up method is quicker the hand lay-up method is the preferred method of consistency. This method produces a more consistent, and uniform layer of coating. The quality of the hand lay-up method does take more time, requires more labor, and longer time for the resin gel to dry.  While being more labor intensive this method does take less skill to apply.

To apply the lining using the hand lay-up method a heavy layer of resin is applied with brushes, rollers, or it is sprayed on. The next step is applying the glass mat to the wet resin and ensuring it is fully saturated with the resin to make sure adhesion is strong. Lastly a seal coat is applied on top of the resin and glass mat. This is only done after the resin saturated material has gelled.

FRP Lining Application Approach

Quality FRP tank coatings rely on how the lining is applied. The standardized approach for applying an FRP hand lay-up tank coating has 5 distinct phases that must be followed.

Prepare The Surface

Organic contaminants build up in steel storage tanks and must be removed. Following this the internal surfaces must be blasted with abrasive materials to prepare the inside of the tank for the primer and resin.

Applying The Primer

Immediately after the blasting is complete the dry film polyamide-cured epoxy primer is applied at a thickness of 1 to 3 mils. It is applied to prevent any contamination of the bare metal surface and to “hold” the tank in condition for the resin phase. Sharp angles in the tank, especially those at the bottom are filled in with a putty type material which includes the fibers and fillers. This putty material should of the same compound as the resin you will use for the tank to ensure proper adhesion. Any deeply pitted tanks should be resurfaced with the same fill material to create a smooth bottom.

Resin Application & Fiberglass Reinforcement

Resin is applied in a heavy layer by brush, sprayer, or roller. While the resin is still wet the fiberglass mat is laid into it and full saturation should be ensured.

The dry film thickness is decided by the full extent of the carrions on the bottom of the tank, and the source of the corrosion. Internal corrosion is controlled by a film thickness of 60 to 80 mils to help protect the bottom of the tank from internal corrosion. The exterior of the tank requires a thicker coating and will end up needing a film layer starting at 80 miles and going up to 120 mils. This helps protect the tank from the external corrosive forces.

Final Coating

A finish coat that is a resin rich layer of polyester resin is applied as the seal coat. This process helps prevent capillary action which causes wicking along the partially exposed glass fibers that stick out of the resin. Paraffin wax aids in the curing process and is added to the base resin that helps produce this seal coat.

Final Inspection

Before the tank is passed for use again an inspection should be carried out to ensure that the FRP lining has been successfully installed. A magnetic dry film tester is used to check the thickness of the dry film. Before the seal coat is applied the thickness of the bottom of the tank should be inspected with a high voltage holiday detector.


Steel Tank FRP Linings In Phoenix

If you have steel storage tanks in the Phoenix area that need to have new fiberglass tank coatings installed All Kote Lining is highly skilled, has the right techniques and is dedicated to getting the job done right quickly and the first time. Give us a call at 480-966-4446 and we can help you will your tank coating needs.

Cooling Tower Water Treatment

Categories:
09/06/2017

 

HVAC systems that keep commercial locations cool create a tremendous amount of heat in doing their job. Cooling towers used in these applications do the job of removing the heat from these systems and keep everything cool and efficient. Vaporization of the latent heat is what helps accomplish this cooling effect. For every pound of water that evaporates in a cooling tower approximately 1,000 BTU’s of heat are removed from the liquid that remains in the cooling tower. The more water that is evaporated, the more cooling power the tower exerts.

All water sources have minerals and solids that are carried in the water that is used in cooling towers. During evaporation the water is removed but the solids remain. They circulate through the cooling tower system and become increasingly concentrated in the water passing through the system. In addition to the salts and solids contained in the water the air used to cool it contain nutrients, dust, gases and microorganisms that are scrubbed out of the air and end up deposited in the cooling tower’s re-circulating water.

Cycles of Concentration

This is a comparison between makeup water and the condition of the water that has been cycled through the cooling tower. The solids carried in the water due to the evaporative nature of the cooling tower and the particulates being scrubbed out of the air contribute to the condition of the water. The industry standard for comparing the source water to the re-circulating water is by measuring the chloride content in both.

Treatment Of Cooling Tower Water

The most sensitive area for water treatment is when contaminated water is re-circulated through the chiller tubes. Certain inorganic substances and biological contaminates are attracted to the heat transfer elements. If these effects are not mitigated by treating the cooling tower water these contaminates collect and coat in the inside of these heat transfer elements. This insulates them and can dramatically reduce the thermal performance of chiller tubes. They can also corrode chiller surfaces and reduce the flow through the chiller overall. Bacteria, scale, biofilm, and corrosion are the four most common issues in the operation of evaporative cooling technologies.

Bacteria Control

For decades the deadly Legionella bacteria has been a recurring problem is cooling towers. The naturally warm environment found in cooling towers along with other biological matter and organic debris help promote the development of the Legionella bacteria. Biocides are used to control the growth of legionella and cooling tower maintenance involves using alternating types of biocides. This alternation of chemicals helps prevent the bacteria from becoming resistant to any one compound. Legionella is relatively difficult to kill because of its resistance to two of the most common water treatment chemicals, bromine and chlorine. Chlorine dioxide and ozone gasses are regarded as highly effective treatments for legionella.

Despite the effectiveness of chlorine dioxide and ozone gasses they are not widely used due to the cost and expertise necessary to administer the program and maintain the equipment that must be used to produce the gasses on site.

Controlling Scaling

Makeup water that is heavy in inorganic salts cooling towers can suffer from scaling on heat exchange equipment. Scaling can prevent the heat transfer surfaces from efficient thermal performance. This will lead to a higher condensing temperature and lower the capacity of refrigerant. In turn the cooling system will require more energy to do its job and will raise the costs. The build up and scaling of calcium is one of the most problematic issues. It precipitates from the solutions at warmer temperatures when in the presence of carbonate alkalinity. Organic polymers and acids are frequently used to prevent and remove these scaling problems. Acids levels must be managed carefully as improper levels of acidity will cause corrosion and premature mechanical failure.

Controlling Biofilm

The systems used in cooling tower systems create an environment for a number of microorganisms. These organisms end up deposited on the metal surfaces in your system and can dramatically reduce your cooling tower’s energy efficiency. These deposits limit the thermal transfer 6 times more so than scaling, due to their higher level of insulation.  To treat the biofilm issues Chlorine Dioxide Gas and ozone are two of the most effective processes. This is due to the fact that these microorganisms are resistant to bromine and chlorine.

Controlling Corrosion

Corrosion is the degradation of metal parts in your cooling tower. This is caused primarily due to the corrosive acidic chemical additives used in cooling towers. There are some microorganisms that also produce acid that has a corrosive effect on the cooling tower. When some chemicals are used to control scaling, bacteria, biofilm and white rust corrosion is a possibility. When corrosion is the result of the chemicals used to control microorganisms it is the fault of the water treatment program. The program should not allow Microbiologically Influenced Corrosion (MIC) but should also not promote excessively high acidic conditions. Once a MIC has been allowed to develop in your system it is hard to eliminate. Prevention is the key to avoid the highly levels of hydrogen sulfide, sulfuric acid, and other corrosive elements.

Controlling White Rust

White rust is possible in new cooling tower systems. It is a serious condition found in new galvanized steel components and cooling towers. They stem from substandard start-up procedures, or the failure to passivate the new cooling tower properly. This condition is made worse by high alkalinity in softened water. Cooling tower manufacturers have guidelines for proper passivation protocols and should be followed when a new cooling tower is installed. While they vary to some degree the use of inorganic phosphates is common. The initial alkalinity should be between 6.5 and 8.0. The heat load should also be controlled during the phase of passivation.


Cooling Tower Water Treatment in Phoenix AZ

If you have a cooling tower in the Phoenix area All Kote’s technicians are highly trained and skilled at chiller and cooling tower maintenance and repair. We can help treat the water, clean the equipment, and apply coatings to help minimize the loss of thermal performance of your HVAC chillers and cooling towers. Give us a call to discuss your industrial cooling towers and what your needs will be in getting the best performance out of your equipment.

Understanding Chiller Tube Cleaning

Categories:
09/06/2017
Chiller-Tube-Cleaning-Phoenix-AZ

 

Taking things for granted is part of human nature. We rarely consider the way everything works and stays working each day when we go about our routines. The ignition fires up our cars, the coffee pot brews up some motivation every morning and we rarely give the things that make our lives comfortable much thought until they aren’t working. This is no different than HVAC systems. A big part of the HVAC system is the chiller, and the tubes that make it work. Understanding chiller tube cleaning helps us keep our chillers working and our buildings cool during the warmer weather in Arizona.

To keep chillers and HVAC systems efficient they need to have regular maintenance and coatings. It is no small task to care for these critical components of the cooling system for large commercial spaces. Coatings help prevent buildup and cleanings kick out deposits that reduce thermal transfer.

Large commercial spaces use a lot of energy and the chiller can be one of the largest consumer of energy. As the price of energy increases, the savings of regular cleaning and chiller coatings increases. Keeping daily logs, making preventative maintenance a priority, and scheduling regular chiller maintenance will keep your overhead costs down.

Key Chiller Tube Cleaning Considerations

Tube Cleaning

The efficiency of the chiller tubes is completely dependent upon heat transfer. Thermal efficiency is limited by buildup on the inside of the chiller tubes. Most large chillers are comprised of literally miles of tubing which helps achieve the heat transfer in the evaporator and condenser. Keeping the tubing clean therefore is the way these critical HVAC components do their job and use less energy. The best way to keep tubes clean is to have planned outages for cleaning, keeping up with water treatment, and having chiller tube coatings which help control buildup.

The efficiency of chillers drop steeply as buildup develops inside the chiller. It is deposited by contaminants in your water that is recycling through your system and by contaminants being brought in from the air cycling through your cooling tower. The contaminants found in your chiller can range from algae, mud, sand and even minerals that develop into scales that all sap the heat transfer.

The percentages of decreased thermal transfer drop quickly even with what seems like thin layers of contaminants. Even a coating as thin as .0045 can drop chiller tube efficiency by as much as 44%.

Water Treatments

Water used in cooling towers and chillers usually comes from local water supplies. This means there can be additives, sand, minerals, and other elements that cause fouling and deposits in chiller tubes. Even the atmospheric conditions around the cooling tower have a significant effect on the quality and contents of the water used in HVAC systems.

This means that there needs to be water treatment in the system to help fight biological growth, scaling, and other deposits. The most contaminated the water the greater need for water treatment and a more frequent and robust water treatment plan.

Chiller Motors & Electrical Components

The chiller motor in your HVAC system is potentially the greatest user of electricity in your entire building. We might obsess about shutting off lights in our homes and offices, but the chiller is responsible for using an enormous amount of electricity to keep our commercial properties cool and comfortable.

Chiller motor maintenance is a critical part of keeping your system efficient and your energy bills as low as possible. The shaft seals, and air vents should be checked and kept clean.  All of the insulation, wiring, and connections should be maintained to keep the system running properly and avoid unscheduled downtime.

Methods Of Tube Cleaning

For the best thermal performance it is clear that regular cleaning and maintenance of the chiller tubes is not optional. It is mission critical and should be carried out on a regular schedule by properly trained and equipped chiller maintenance technicians. There are different methods that these technicians use to get your tubes clean and maintain the thermal efficiency of your chillers.

Chemical Cleaning

One of the older methods of tube cleaning, is has seen a decrease in use in the last decade. Acid solutions are used in chemical cleaning that soften and break down the scale and deposits in the tubes. The acidic solutions are circulated through the tube bundles and help remove the layers of energy robbing debris.

Chemical cleaning does have the advantages of breaking down mineral scale so brushes can effectively remove them, and it can take tubes back to bare metal. It has lost some of its former popularity because it is time consuming, the chemicals are costly, requires increased training, and the chemicals are dangerous and difficult to dispose of.

Rod & Brush Cleaning

The rod & brush method is very similar to the cleaning of a gun barrel. It is probably the oldest type of chiller cleaning. A rod of metal is tipped with a wire or nylon brush that is larger than the tube. The process generally involves flushing the tubes with water, and then forcing the rod and brush through the tubes. After the rod has been pushed through water is sprayed again to remove any debris.

This is a popular method because it is inexpensive, but it does have some disadvantages. It is labor and time intensive. The chiller might be in an area that prevents the longer rods being used. Smaller sections might have to be assembled as the brush is inserted into the tube, adding to the time of the job. Also the bristles on the brush tend to fold down and end up swabbing instead of brushing. Another limitation of this process can be if the tubes brushed first dry and the debris reattaches before the final rinse is completed.

Rotary Tube Cleaners

Using either an air or electric motor these chiller tube cleaning machines include a cleaning tool that uses water and circular motion to help remove debris. A flexible shaft is set inside a plastic casing which directs water directly to the cleaning head. The tools used with these machines include scrapers, hones, brushes, and buffing tools. This combination of tools is what makes the rotary tube cleaners some of the best at removing deposits, including hard scale. The job is done by one operator feeding the shaft through each of the tubes. Best of all it only takes one pass for each tube.

This is one of the most used, and popular chiller tube cleaning types. It is due to the fact that is it one of the most effective cleaning methods paired with the low cost. The process takes little time and uses less consumables that other cleaning methods. It also only requires one technician, only opening one side of the chiller, and is the best type of cleaning for internally enhanced chiller tubes.

Tube Cleaning Guns

As the name suggests this method of tube cleaning features a gun that uses air or water to shoot a projectile through the tubes. These projectiles vary from metal or plastic scrapes to brushes and even rubber bullets.

This is a popular type of cleaning for light deposits and is very fast. With the right conditions tubes can be cleaned quickly, even in a matter of seconds per tube. It does have the limitation when it comes to the type of deposits it can remove. Harder scaling or stubborn deposits are more difficult or impossible to remove with this method. It also requires the opening of the chiller on both ends to allow the transfer of air as the projectile goes through the tube.

The equipment can be costly to buy and maintain along with some units being somewhat dangerous to operate. The pressure released into the tube might not make it through and be rejected at the operator when the gun is removed. Some units include pressure relief valves that prevent this danger to operators.

On Line Cleaning Systems

Cleaning systems are available for use while the system is active. This means that they help reduce the frequency of downtime. There are two on line tube cleaning types available today. One uses foam balls that circulate through the tubes in the chiller and the other includes the use of plastic brushes that are installed into each of the tubes. The idea behind the foam balls is that they should work through each and every tube in the bundle often enough that they will clean the tubes from becoming dirty. The plastic brush system features plastic baskets which are permanently attached to both sides of the chiller. Periodically the direction of the flow of water is reversed to cause the baskets and brushes to travel the length of each tube, removing debris.

With proper water treatment these systems can reduce or even eliminate the needs for tube cleaning. However these systems are costly to purchase and install. They also are not suitable for chillers that use hard water that promotes hard scaling.

Internally Enhanced Tubes

The only cleaning method for this type of chiller tube is rotary tube cleaning. These chiller tubes are making advancements with thermal efficiency and are becoming more and more common. Internally enhanced chiller tubes are those that include rifling on the inside. Rifling is when spiral groves run the length of a tube. They cause the water to circulate more evenly and provide increased surface area. Both of these elements increase the chiller’s thermal efficiency.

The rifling does mean there are areas that are below the surface of the metal. This means that many cleaning methods are simply not suited for getting into these crevices that increase efficiency. The best type of rotary tube cleaners to use in these applications are bi-directional units. This means that on the way in, and the way out, the brushes can be moving in the same direction as the spiral inside the tube. Specialized heads have also been developed to get into these grooves.

Chiller Maintenance in Arizona

If you have a chiller in or near the Phoenix valley All Kote Inc. can help you extend the life of your chiller and your cooling towers. Regular maintenance and repair keeps the system energy efficient and can save users huge amounts of energy and that means real savings on electricity bills. If you have a commercial space that uses and chiller or cooling tower make sure that you have a plan for maintenance and have All Kote help you with your chiller and cooling tower needs.

Keeping Cooling Towers Clean

Categories:
09/06/2017

 

Keeping cooling towers clean does more than just improve efficiency, it helps keep occupants healthy. Dirty cooling towers use more energy to do the same job. Also towers that are not kept clean can be breeding grounds for germs and bacteria.

While just about everyone has heard of pneumonia most people aren’t aware that it can be caused by dirty cooling towers. Legionnaries’ disease in cooling towers can spread bacteria and germs. One of those bacteria is the Legionella Pneumophila. The CDC states that “Water within cooling towers is heated via heat exchange, which is an ideal environment for Legionella heat-loving bacteria to grow. “

Regular Cleaning & Disinfection

The way to having clean towers and healthy occupants is regular cooling tower cleaning. OSHA recommends opening up your cooling towers for visual inspection and cleaning on a quarterly basis, or at least twice a year if the cooling tower is not used year round. Addition cleaning and maintenance tips include:

Using Biocides – Control your cooling tower’s bacteria with biocides. This will help keep the water inside your system from becoming overrun with bacteria. It is however limited if there is high levels of dissolved solids or organic matter in your water.

Keep Water Under 68°F – The sump water in your cooling tower should not exceed 68°F, or 20°C. This helps control the development of bacteria. The exact temperature of the sump water varies based on design, flow rate, heat load, and your wet and dry bulb temperatures.

Cleaning Frequency – If the cooling tower isn’t running during the winter time it should be cleaned before use, and at shut down at the end of use in the fall. Cooling towers that run all year long should be cleaned at least once every 3 months.  If the system experiences high bio-fouling due to water conditions the cleaning should be more frequent. New systems and systems that have not been in use for extended period of time should always be cleaned before use.

Monthly Inspections & Online Maintenance

In addition to the semiannual or quarterly cleaning a monthly inspection of equipment should be performed. This helps catch problems while they are small and cost less to address. It also avoids the development and spread of bacteria. To see where you cooling tower bacteria levels are there should be a monthly analysis of the microbiological condition of the cooling tower. Online maintenance includes using biocides and rust inhibitors that are fed continuously during the operation of your cooling tower.

Required Recordkeeping

All operation and maintenance should be logged in a book. This should include all of the activity associated with the cleaning of the cooling tower. That includes the inspections, cleanings, water quality results, bacteria outbreak investigations, and any maintenance done to the tower. Up to date records should be kept that describe the design, components, and make-up water of the cooling tower system.

Additional materials should be made available that detail the proper operation and maintenance of the cooling tower system. This should include the use of corrosion, scale, and antifoaming products used in the cooling tower. Any chemicals added to the system should be recorded to accurately track changes to the development of bacteria in the cooling tower.

Phoenix Cooling Tower Cleaning

If you have a commercial property it is important to keep the cooling tower disinfected and clean. The spread of bacteria from the cooling tower poses and health concern for your visitors and costs you money in energy costs. Before you fire up a cooling tower that has been shut down for the season, or for a longer period of time, it must be inspected, cleaned, and disinfected. This helps fight the spread of disease and cuts down on your overhead. To get your cooling tower cleaned call All Kote Lining at 480-966-4446.

What Are Industrial Chillers?

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09/06/2017
What-Are-Industrial-Chillers

 

Are you searching for “What Are Industrial Chillers?” If so All Kote Lining Inc. has you covered with both information about what they are and can handle any of your chiller repair needs in the Phoenix metro area. Industrial chillers are designated for use as refrigeration systems which cool process fluids. They are also used to dehumidify air in industrial or commercial facilities. Chillers will use either absorption cycles or vapor compression to cool. The water that is chilled by these machines are used for various applications including cooling industrial fabrication processes and to cool large commercial spaces.

Industrial Chiller Types

Each chiller has a rating of between 1 and 1000 tons of cooling energy. There are three main categories or types of chillers, evaporative condensed, water, and air chillers. Each of these types also have 4 different technologies for getting the job done, absorption, screw driven, reciprocating, and centrifugal chillers. Screws driven, reciprocating, and centrifugal are all mechanically driven systems, absorption chillers differ in the fact that it operations via a heat source and has no moving parts.

Industrial Chiller Components

Mechanical compressor type chillers have four basic components stages that the refrigerant must pass through. These are going through the evaporator, then compressor, condenser, and lastly the expansion valve. Evaporators operate at lower pressure and temperatures than chiller condensers.

How Industrial Chillers Work

Chillers work by passing refrigerant, typically water or air, through a series of components to change the condition of the refrigerant to expand and contract. This process results in heat transfer and cooling for the purpose of cooling industrial fabrication processes, or air for HVAC systems in large commercial buildings.

Condenser Stage

Condensers are the start and end of the cycle for chillers. As the refrigerant passes through the expansion valve it returns to the condenser as a super heated gas. It must be brought back down to the level where the gas is at the saturation temperature. This is the point where the condenser can start condensing the refrigerant back into a liquid. This is done by continuing to transfer heat from the refrigerant to the air. The system will continue until the refrigerant is completely condensed back down. In theory this process happens at the outlet of the condenser. In application a degree of subcooling is expected at the condenser outlet. To prevent liquid flashing subcooled liquid helps avoid pressure losses in the components and tubing.

Lowering Refrigerant Temperature

When the liquid leaves the condenser it is under high pressure and is at a high temperature. Before it can be used as a refrigerant again it must be cooled. This is accomplished by reducing the pressure the refrigerant is under. The relation between the pressure and temperature is a law of physics and you can count on the refrigerant cooling if the pressure is lowered.

To reduce the temperature pressure is reduced by first having a system of pressure restriction. This is accomplished with a thermostatic expansion valve. This is useful as the pressure varies based on the load on the system. A thermostatic expansion valve can adjust for load, pressure, and temperature variations as the system has lower and greater loads applied. This valve will act to lower the pressure, and by affect the temperature of the refrigerant. The valve is limited to only produce a predetermined pressure change that fits with system design and load conditions.

The cycle has dropped in the thermostatic expansion valve. When there is a mixture of both liquid and vapor states of refrigerant Subcooling or superheating is not possible. For this reason any place in the system where both states of refrigerant exist, the pressure and saturation temperature will match.

A portion of the liquid refrigerant must boil to help exchange sufficient heat to lower the temperature of the system. This is another process that results in heat transfer and lower liquid temperature. When there is a large difference in temperature between the liquid and vapor states more refrigerant will need to be boiled off to achieve saturation temperature. This process improves greater refrigerant quality.

The last stage of the refrigerants journey is a mix of vapor and liquid. It passes through the evaporator tubing and warm air is blown over the evaporator. This is where the heat is transferred to the boiling refrigerant. The latent heat gain experience by the refrigerant causes to temperature increase, yet it does experience a change of state. In the best case scenario the last molecule of liquid refrigerant boils off by the evaporator outlet. This is then passed through the to the compressor inlet. This is how the refrigerant is passed back to the start at the condenser.

Phoenix Chiller Maintenance & Repair

If you have a Chiller in the Phoenix valley it needs regular maintenance to work without using too much energy. The tubes need regular cleaning and coatings can be applied to help reduce scaling and build up that rob you of energy. If you need chiller repair we can also help you get your system back up and running. We also work on cooling towers that are commonly associated with chiller systems. We offer a complete maintenance and repair service for all industrial and commercial chillers in the Phoenix valley. Call us today for service at 480-966-4446

Cooling Tower Maintenance Tips for Good IAQ

Categories:
09/06/2017

 

Comprehensive and regular cooling tower maintenance saves time, energy, and money. It also extends the life space of the equipment at your facility.  IAQ, or indoor air quality is a matter of health and comfort in our large industrial and commercial buildings.

The EPA is sighting a number of factors that contribute to diminished air quality in our buildings. Some of these factors are pressure to defer maintenance and building services to reduce costs, reduce ventilation to reduce energy use, the use of tighter construction envelops, and an increase in chemical pollutants in commercial and consumer products. These factors contribute building occupants noticing and complaining about stuffy air, odors, and symptoms of discomfort of illness.

Inadequate Maintenance

Poorly maintained HVAC systems often are the problem when buildings have poor IAQ. The HVAC system can be the ideal breeding ground for the buildup of bacteria. Areas that are common to develop these problems are duct surfaces, cooling coils, and drain pans. When contractors are trying to track down the source of odors the building’s central air conditioning system should be the first place to check. This is especially true in hospitals as they are areas where a greater number of antibiotic resistant superbugs are on the rise. It is a priority to prevent these bacteria and viruses from ever taking root in centralized air management systems.

The use of ultraviolet lights can help control airborne pathogens. In this case the ultraviolet lights need to be the ultraviolet-C type. These lights utilize pathogen killing UV-C energy to inactivate the illness causing airborne pathogens. These systems can be applied to the coil systems in new systems. They can also be retrofitted to work with older technology. Not only does adding UV-C lights help cut down on germs but it also helps address diminished heat transfer or pressure drops due to coils that are fouled. Keeping the coils clean in HVAC systems makes the system run more efficiently and use less energy all year long.

While managers and building owners are aware of IAQ issues, they are also worried about the costs involved in installing and maintaining IAQ products. Some building owner are also skeptical about the claims by IAQ product manufacturers. What needs to be realized is that installing IAQ products does more than help keep air cleaner, but also helps protect air handler coils from bacteria and mold. The cost of installing UV is typically less than 15 cents per cfm. This investment cost is far less than the potential savings achieved through UV system integration. This can be as high as 10-25% in maintenance and energy savings.

Regular HVAC Cleaning

A regular maintenance program is critical to all buildings, but more so of those that use cooling towers. Cooling towers can be a breeding ground for Legionella, which causes Legionnaries’ disease. There is a high demand not only from city, but OSHA, to keep these facilties free of Legionella. The prevention of an outbreak is high priority not only to mitigate risk, but also to improve the health and well-being of building occupants.

The regular HVAC and cooling tower maintenance should include the cleaning of cooling tower basins. The basins are a prime area for the growth of legionella. This is due to the buildup of mud, dirt, and stagnation of water. This tends to develop a biofilm that supports the development of the dangerous bacteria. Cooling tower vacuums can help break up and remove d the silt and mud. This leaves cooling tower basins safer, cleaner, and simply operating more efficiently.

The fill material in cooling towers is also an area in which biofilm occurs. The regular cleaning efforts should include the removal and debris, lime scale, and other biological matter. Fill can be cleaned with pumps to improve water flow, remove scale, and slow the development of bacteria. The fill material can also be removed and upgraded. Newer designs of film help increase water to air contact time, which boosts performance.

Regular maintenance is important in prevention of legionella and bad IAQ. It also helps reduce energy costs, avoids downtime, and helps prevent equipment breakdown.  Regular maintenance is much quicker and less costly than more involved repairs. When systems fail and shut down because of problems the downtime is longer, the repairs more involved, and the cost much higher. This means proactive maintenance programs are much less expensive than waiting for something to go wrong, or people to get sick.

Schedule Your Cooling Tower Cleaning

If you have a HVAC system that is paired with a cooling tower system in the Phoenix area, All Kote is here to help. We want to help you realize the savings in regular maintenance in terms of life span of your equipment, reduce downtime due to larger scale repairs, and generally better air quality in your buildings. Regular cleaning will save you money, keep your employees and customers healthier, and it will help prevent the development of dangerous bacteria like Legionella. Give us a call today to find out how we can help you at 480-966-4446.

Water Cooling Tower Inspections

Categories:
09/06/2017
Water-Cooling-Tower-Inspections-Phoenix-AZ

 

If you are searching for “Water Cooling Tower Inspections” you are either looking for a guide to help you understand the process, or you are looking for a company to handle the job for you. Cooling tower maintenance helps save energy, and extends the life of equipment. The type of cooling tower has a huge effect on how inspections are conducted. Large multi-cell industrial cooling tower systems are naturally more involved than small packaged units. This article will help explore elementary considerations in conducting cooling tower inspections that are relevant to the majority of units.  As with most things there are different methods for accomplishing this task, this article covers just one way to conduct a cooling tower inspection.

General Site Conditions

A great practice in cooling tower inspection is to start with a site evaluation. The first thing to look for is if the cooling tower is clutter free. It’s also important to note if there is discharge flume returning to the inlet which is also known as re-circulation. It is also important to note if the discharge from the cooling tower is being evacuated properly not to interfere with the fresh air intakes. The last item to note is if the physical access to the cooling tower is controlled with locked doors, gates, or other personnel controls.

Site & Unit Identification

Knowing which equipment you are inspecting is one of the most critical steps. Different systems have various operating parameters and operation manuals. For thorough inspection to be conducted you should identify the serial number, model number, and manufacturer. If this information is unavailable or there isn’t a nameplate you should take detailed notes for future reference.

Site Environment

Cooling towers operate in various areas and geography. In heavily wooded areas cooling towers can become fouled or contaminated by sources of debris. These include trees that release pollen, have falling leaves, or other similar debris that can cause diminished cooling tower efficiency. In other arid areas there is a danger of the cooling tower being affected by dust, soil, sand and other materials that can get blown into the air and sucked into the cooling tower system. You should also note if there are an industrial processes that might be exhausting chemicals that could be sucked into your cooling tower.

Many times cooling towers capture a significant quantity of sand and dirt from the air. When this happens it can clog nozzles, get trapped in fill material, and coat heat exchange equipment. Each of these conditions diminishes cooling tower efficiency.

Check Process Water

The water that is used as the coolant in the heat exchange system and cooling tower can become contaminated by the various sources of debris. Visually checking the water quality in the cooling tower can be an important step in checking the condition of the system. Check the water temperature at the inlet for its quality. Pay attention to any solids that are either dissolved or in suspension in the water. Generally just ensure that the water is clean. If it isn’t the cooling tower might experience temperature peaks when in use as the water contaminants will cause higher run temperatures.

Unit Inspection List

These are the following areas that need to be inspected cell by cell. As each component is inspected adequate photos should be taken to catalog the condition of the cooling tower for future reference.

Frame Inspection – The frame is the structure the entire unit operates in. You should inspect the frame to check for areas that might compromise the structural integrity of the cooling tower.  Also look for missing or loose cooling tower components.

Pipe Inspection – There are two main pipes that need to be inspected, the pipe that is part of the cooling tower and the pipe that runs beyond the perimeter of the cooling tower. Things to look for are that the pipe is installed correctly and ensure that the pipes are in good condition.

Fill Inspection – The fill needs to be inspected to see if there is any fouling or deposits that would interfere with air or water circulation. If there is physical damage to the fill, fouling, clogging, or uneven water distribution the fill isn’t working up to its design specifications.

Drift Inspection – Drift eliminators are designed to prevent the loss of water during cooling tower operation. During operation air is circulated through the system inspection should note if there is an excessive amount of water exiting the system through the drift eliminators.

Louver Inspection – If equipped the louvers should be inspected to ensure proper installation, condition, and that they are not caked with debris.

Inspecting The Cold Water Basin – The structural integrity of the basin should be inspected much like the frame.  In addition the basin should be inspected for corrosion, leaks, debris, algae growth, even water distribution, particle deposits, anti-vortex devices, and uneven temperature.

Inspecting Hot Water Basins – If the system includes a hot water basin it should also be inspected like the cold water basin. There should be no dry spots, no overflow or signs of overflow, and it should have adequate water distribution.

Mechanical Equipment Inspection – Review the overall condition of mechanical equipment for abnormal vibration, unexpected noises, overall structural integrity, and watch for leaks from any of these cooling tower components. If you are able to check the RPMs, airflow, and amperage of the equipment used in the tower it will help identify faulty mechanical equipment.

 Phoenix Cooling Tower Maintenance

Keeping your energy costs down is a big priority of every commercial and industrial facility in Arizona. HVAC systems are one of the largest draws of electricity for commercial and industrial buildings. Cooling tower inspection and maintenance helps ensure that all of the components are working properly and operating at their highest design capacity. When these components are working properly the cooling tower will run with less energy and will cost your business less. For Phoenix valley cooling tower maintenance call All Kote Inc. at 480-966-4446.