Water/Waste Water Treatment
This market covers the drying of air or oxygen to make ozone in sewage treatment plants. Ozone, a strong smelling gas, exists in greatest quantities in the upper layers of the earth’s atmosphere. To exist, it requires a substantial amount of energy, which it gets from the sun.
At normal temperatures and pressure found on the earth’s surface, ozone (O3) is unstable. It decomposes into molecular oxygen (O2) and atomic oxygen (O). Since ozone and atomic oxygen have considerable oxidizing power, this gas becomes a prime choice for eliminating color, taste, odor, bacteria, and viruses from water.
In addition, ozone has numerous advantages over other disinfectants: it leaves no traces; its reactions do not produce toxic halogenated compounds; it acts more rapidly and more completely than other common disinfecting agents; it is the most active, readily available oxidizing agent; and it has the ability to react swiftly and effectively on many strains of viruses.
Ozone can be produced from oxygen in the air or from pure oxygen. For the continuous production of ozone, feed gas is circulated between two electrodes separated by a narrow gap. The application of a high voltage alternating current creates an electric field throughout the gap which acts on the oxygen to form ozone. Before the gas enters the ozonator it must be dried. This is done by using a refrigeration unit followed by a desiccant dryer. Exit dewpoints out of this system are usually around -76°F.
Digester gas or land fill gas is recovered and utilized to fuel the motors of generators which produce electric power. Moisture in this gas can greatly reduce the life of the generator motors when it forms acids with the impurities typical of this type of gas. Other applications include tank vent breathers for sulfuric acid storage tanks and air dryers used in chlorine padding applications.