Dissolved oxygen(DO) levels were regulated by a gas/water mixing machine in closed recirculating system for the culture of juvenile rainbow trout Oncorhynchus mykiss.

For the demand of the cigarette process revamping the Automatic Controller,the spraying humidifier system by gas-water mixing reminds constant pneumatic and hydraulic pressure,achieves no piecewise linear adjustment.

According to comprehension experiment, show the change low of drain height with the gas quality supplied after drain line of the raker injected compressed air, compare the effects of three types of gas-water mixers to drain height, expand the range of pump application, provide technical basis for manufacturing and using gas-water mixers.