The images to the left are of a DESOZONE dual stage odor control system. Dual stage refers to the two integrated scrubbers that are oriented in series. In this particular system the first stage is alkaline and the second stage is acid, but they could both be alkaline depending on the application for the system. In this case the first stage has been selected for removal of hydrogen sulfide while the second stage is designed to remove ammonia. The first photo shows the DESOZONE system under test from the alkaline scrubber side. You can follow the overall process by referring to the DESOZONE process diagram.
The second image down shows the two scrubber stages. The grey PVC pipes are the spray bars. The bottom bars sprays a dilute solution of sodium hydroxide over the scrubber packing in the first stage. The top PVC pipe sprays a dilute solution of sulfuric acid. The spray bars are driven by pumps on each side of the unit. In the top image you can see a blue centrifugal at the bottom left hand side of the system. This is the sodium hydroxide pump. It is located next to a small rectangular tank that holds the concentrated sodium hydroxide solution. A pH controller/metering pump adds sodium hydroxide to maintain the pH of the scrubbing solution being sprayed over the packing. A similar system for the acidic stage is employed on the opposite side of the unit.
The blue motor on the top left hand side of the third image drives the blower. The contaminated air first passes along the length of the alkaline scrubber on the left hand side of the DESOZONE unit. When the air reaches the end of the scrubber it passes through a demister and then is directed back through the acidic stage of the unit. The air passes through another demister and the exits through the opening shown in the picture near the center of the right hand side of the DESOZONE system. The air is now free of odor and can be vented to the atmosphere.
The fourth picture shows the inside of the control cabinet. In addition to the power supply unit and controls, this cabinet also contains the ozone generator. The ozone is mixed with the sodium hydroxide the oxidize the hydrogen sulfide and other species (such as mercaptans). The blue canisters are air filters for removing oil and particles from a compressed air stream. The metallic cylinder is an water cooled ozone generator which converts a portion of the oxygen in air to ozone. In between the filters and the ozone generating cell are pressure regulating valves and a membrane type high pressure air dryer.