The importance of water in the cooling tower industry – Water (part 2)
Water as a means of energy-heat transportation
Excessive heat not used by machines must be removed. This is important to avoid accumulated heat and, hence, compromise the functioning of the machines.
One would think that a quick remedy for this type of problem is to use as an element such as a current of cool air that can transports the heat away from the machine and, hence, cooling it down.
But, on the other hand, if you think about it, this would require huge amounts of air because we are we talking about cooling industrial machines such as welding machines, chemical reactors, machinery for molding plastics, etc.
There is another element that is available in nature and is much more effective than air for heat transfer and, thus, cooling the machine: it’s water.
The temperature of water changes slower than the temperature of the air because water has a higher heat capacity. Hence, the water is more convenient for the purpose of cooling machines.
Amount of water needed in manufacturing plants
Let’s try to calculate how much water is needed for a small plastic molding plant to cool its machines.
Such a plant, with a work force of 20-30 people working 8 hours a day, would require 40 cubic meters of water/hour to cool its machines, or better 40,000 liters/hour which corresponds to 320,000 liters/day. This amount of water is only for a single small plant.
The higher the installed power (the sum of the nominal powers of all power consuming devices in the installation), the more the heat to be disposed of (the yield is proportional to the installed power), hence, the greater the amount of water is required.
Other examples can be carried out with data from steel factories, oil refineries, food industries, cold stores, and any other manufacturing plant.
The need to recycle water
As we mentioned in part 1 of our article, water is a precious resource and is precious to life. Wasting water, besides being a waste economically, precludes resources that can be used to the benefits of all.
Water is plentiful for civil, industrial and agricultural use but, unless it is saved and wisely use, it will be compromised.
In the calculation of the previous paragraph, we found that a small plant would need a capacity of water flow of 320,000 liters/day. This daily consumption of water corresponds to daily water consumption of a country of 1,280 people for civil use. In the western world, we have an average consumption of 250 liters of water per person.
Therefore, since it’s very inconvenient and difficult, if not impossible, to have a cooling system with “water to waste”, we can reuse (recycle) the same water by putting it back into circulation.
But be careful! The same already hot water, at the end of the second cycle, will be much hotter.
This is why after a period of time more or less long, the water and the machine will have the same temperature. As a consequence, the yield will drop dramatically until total block of plant production for which the machine itself was accounted for.
Hence, the need to cool water full of heat coming from the manufacturing machines with a cooling tower.