Before any further processing can take place, fish and molluscs must be gutted and cleaned. Worktables are outfitted with suitable vacuum nozzles that extract the entrails from the fish. A central vacuum system then pipes the combination of liquid and coarse particles through a filter where they are separated for proper disposal.
The fish food distribution is arranged through pressure pneumatic systems from barges or ships to the fishes in open water (aquaculture cages).
Vacuum is used to suck live fish mixed with sea water from fishing boats, farming basins or buffering pools to processing plant, and from feeding cages to grading machines. Vacuum pumps are also used in pressure mode to displace live fish from the storage vessels to the slaughter point.
The water's oxygen content can be substantially increased using rotary lobe blowers, which increases the volumes of fish that can be kept in a pond. In this process, air is drawn from the atmosphere and forced through an inlet into the tube aerator. It is then diffused into the water through tiny openings and rises in fine bubbles. The oxygen in the water causes the fish to grow and multiply more rapidly, significantly increasing the yield.
Air and the oxygen that it contains have harmful effects on the quality and durability of fresh food. For this reason, many processes need evacuation. The classic vacuum application in this field is vacuum packaging. Before sealing, a centralized vacuum system evacuates the air out of the packet. Suction groups are used in numerous packaging machines for industrial use.
The aeration tanks in wastewater treatment plants are activated with oxygen by using compressed air. A thorough mixing of the sludge with oxygen increases the gas yield and reduces its retention time in the tank. Blower or low pressure screw compressor technologies can be found in fish process wastewater treatment plants.