The invention provides a device and a method for deoiling by entraining, refluxing and reusing multistage baffling microbubble flotation, and relates to the technical field of deoiling of oilfield
produced water. The multistage baffling microbubble flotation oil removal device for entrained air
backflow recycling comprises an air flotation tank, a dissolved
air pump and an
electric control system, and a vortex reactor, a T-shaped water passing opening and an adjustable oil collecting groove are arranged in the air flotation tank; a
nitrogen pressure automatic balancing pipeline
system, a
nitrogen entraining return pipeline, a dissolved
air water replenishing pipeline, a dissolved
air water return pipeline and an oil-containing
raw water extraction pipeline are arranged outside the air floatation tank; the air dissolving efficiency is improved and the particle size of
microbubbles is reduced by controlling the inlet and outlet pressure of an air dissolving pump; the vortex reactor slows down the bubble gathering and floating speed and prevents short flow; according to the
nitrogen pressure automatic balancing pipeline
system, a stable
gas phase space can be formed at the inner top of the air floatation tank, the liquid level is kept stable, separated nitrogen serves as a gas source of the gas dissolving pump to be recycled, and the consumption of the nitrogen is greatly reduced.