Canadian Food Approvals on Water Treatment Chemicals supplied by our supplier Jacklyn Industries are available. Link for products approved in left column.
COOLING TOWER CHEMICALS
Evaporative cooling systems are used in comfort air conditioning and in Industrial applications to remove heat from the circulating water. These systems need Cooling Tower Chemical Treatment.
Circulating water is distributed over an effective dispersing media in the Tower. Forced air is pushed against this flow causing intimate contact with air and water resulting in rapid evaporation. Heat is released from the bulk circulating water and the water is effectively cooled. In the process of evaporation the original dissolved solids in the water are concentrated. In most installations this concentration process will proceed to a level where some of these dissolved solids will exceed their solubility level and precipitate. These precipitates will form deposits on heat exchange and distribution surfaces. The result is reduced flow, poor heat transfer and corrosion, ultimately resulting in system shut-down or failure. As the Chiller Condenser tubes develop deposits the electrical energy costs to operate the compressor will increase.
The expected average Extra Energy cost at today's prices would be
Cooling Tower Scale Deposit Extra Electrical Cost / year due to Efficiency Loss
1/32 " $8000 Canadian / 1000 TONS of Cooling
1/16" $20,000 Canadian / 1000 TONS of Cooling
5/64" $26,000 Canadian / 1000 TONS of Cooling
CORROSION IN CLOSED LOOPS
Another serious problem inherent in this system design is corrosion. With the circulating water continuously exposed to air, it will become saturated with oxygen and other corrosive gases. Without some form of chemical protection, the result will always be pitting and or general corrosion with metal loss and eventual system failure.
BACTERIA IN COOLING TOWERS
A third problem that develops in all exposed evaporative systems is the evolution of aquatic growth. Many forms of algae, bacteria, molds and fungi thrive in this environment. This condition is exacerbated by the action of the cooling tower where the system functions as a giant scrubber removing particulates from the air. These particulates in themselves cause problems by contributing directly to deposit formation. In many cases they can also become a food source for bacteria. Heavy infestations of bacteria will result in slime and biofilm development. Biofilms as with other forms of deposition will result in reduced operating efficiency and corrosion.
The presence of many bacterial strains such as Legionella Pneumophila represents serious hazards to human health. (ie Legionaires Disease) This type of bacteria is normally carried in airborne water droplets. The water droplets can be passed into the heating and cooling ducts and end up where people live and work.
It is extremely important for many reasons that Cooling systems are maintained as clean and corrosion free as possible. Bacteria and other forms of aquatic growth must also be controlled within acceptable limits.
SAND FILTERS
The use of Sand Filters on Cooling systems that have a lot of air contamination is a good idea. It can help reduce biocide requirements, prevent plugging of the spray nozzles and reduce in the maintenance and cleaning of the Tower.
S.P. Thermal Systems Inc. offer a broad range of chemistries for use in evaporative water systems from which we can design a program well suited to your application. We provide an excellent selection of chemical feed, filtration, ion exchange, bleed control and fully automated control, monitoring and reporting equipment. We have something to satisfy every need, and every budget. We support our sales with regular scheduled service visits and customized operator training programs.
Please call us to arrange a full systems evaluation, without obligation.
Water Treatment Chemicals for Closed Loop Systems.
All Closed Systems require treatment to control problems which will occur over a
period of time. A Radiator system in a car is a closed loop system. If this was not
treated sooner, or later the radiator and pump would fail. The same concept
applies to closed systems such as Hot Water and Chilled Water Loops.
Water which is used to fill Cooling or Heating Loops is normally corrosive and contains
dissolved oxygen. The metal piping material found in Closed Loops is normally mild steel.
With out treatment corrosion occurs under these conditions releasing flakes of rust into the
circulating system. These particles cause serious damage and abrasion to pump seals
and shafts. Over time the system will fail due to metal loss
Most closed loops have equipment such as expansion tanks and relief valves
to compensate for pressure changes or water losses. Expansion tanks usually have a
volume of air trapped above the water in the tank. The dissolved oxygen in the water is
released throughout the closed system. As make up water enters the system from bleeding
air or because of water leaks, more fresh water loaded with oxygen enters the closed
loop. As leaks and losses are normally undetected for long periods of time the
oxygen contaminates the closed loop by attacking the metal piping, resulting in corrosion
cells forming as a pit. When this occurs equipment failure normally results.
How to check Closed Loops to determine if corrosion is happening.
The following simple test of the water will determine the answer.
Check for color and clarity. It should be clear
Check if the water has more than 1 ppm of iron using an iron test
Check the ph of the water. It should be above 8
If any of the above is happening corrosion is occurring.
Restoring Control using Chemicals
A blend of either Molybdate treatment or Sodium Nitrite with an azole to protect yellow metals
such as copper or brass is used to combat corrosion in closed loops. These products
form a protective monomolecular film which prevents the oxygen from attacking the
metal surfaces.
The results of a good chemical treatment program will provide higher heat transfer
and will save on expensive repairs.
Closed Loop Deposits can be removed by the use of bypass filters to keep the system free of deposits.
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