The utility model discloses a multilayer pump for
coal bed gas drainage, which comprises a working
barrel, one end of the working
barrel is provided with a sealing seat, the top end of the sealing seat is provided with a
tail end main body, a flow suction cavity is arranged between the sealing seat and the
tail end main body, and the top end of the
tail end main body is connected with a first series main body; according to the multi-layer pump for discharging and adopting the
coal bed gas, the multi-layer pump adopts multi-stage
jet injection, consists of a multi-stage
nozzle, a suction chamber, a
mixing chamber, a
diffusion part and the like, and is free of
moving parts and shaft seals, so that the multi-layer pump is more convenient to repair and maintain, the operation cost is reduced, the multi-layer pump can smoothly pass through inflection points, and the service life of the multi-layer pump is prolonged. The device has the advantages that the device can carry pulverized
coal and tiny particles well, pump clamping is avoided, eccentric wear is avoided, the pump inspection period is long, maintenance is simple, stability is good, the pump inspection and well repair period and production and
recovery benefits can be improved, multiple sections of serially-connected main bodies can be added according to working condition requirements, and the working efficiency is optimal.