Red circleroadsignmeaning

Temperature difference across the heat exchangers (heat balance) is used to ascertain if the heat exchangers are fouled. This will indicate problems with a cooling system.

The cooling water system is started up before the rest of the plant processes and is shut down after the main processes no longer require cooling.

Normally run at top speed to give the maximum amount of cooling. In winter, the fans can be slowed down or reversed to deice the cooling tower.

Red signwithwhitediagonal line

Ozone Treatment involves the use of an ozone generator. Ozone is injected into the cooling water and very quickly kills bacteria, slime and algae.

The pumps are normally centrifugal and are used to supply a large volume of water at a low pressure (300-500 kPa). The pumps can be electrically driven or turbine driven. When the main cooling water pumps are turbine driven, an electric driven pump is used for start up and pretreating the system, when steam is not available.

This means that little makeup or blowdown is required. The cost of the chemical treatment program is also low. The disadvantage of ambient air as the cooling medium is the temperature of the cooling water is restricted by the temperature of the air. With refrigeration systems, the initial cost and operating costs of the system are higher.

Red circlewithwhiteline roadsignmeaning

Operation of the cooling water systems depends upon the cooling water pumps to supply cooling water to the plants heat exchangers and back to the cooling tower. Cooling water pumps normally take suction from the cooling tower basin. There are screens between the basin and the pump suctions.

Streetsignwithred circleandwhite barNYT

Pumps take water from the cooling tower basin. Balancing the cooling water flows through the cooling water heat exchangers can reduce the pumping horsepower of the pumps.

Red signwithwhiteline meaning

Microbiological Fouling (Bacteria, Slime, and Algae)– Can be destroyed with biocides such as chlorine gas, sodium hypochlorite, and bromine.

In this system, the heat picked up in the various coolers and condenser is released in another type of cooler called a chiller. The cooling medium can be ambient air, or it can be a refrigerant. The purity of the cooling water is easier to control because the water is not exposed to the atmosphere. No cooling water is lost to evaporation.

Corrosion- Most common corrosion inhibitors are chromate-based inhibitors, polyphosphate-based inhibitors, and organic-based inhibitors.

Cooling water blowdown is et to control the concentration of the cooling water. Conductivity is often used to set the blowdown rate. If limit is exceeded, scales of calcium and magnesium start to deposit in the heat exchangers.