The invention discloses an ultrasonic-assisted automatic
backwashing filter device which comprises two filter cartridges, a water outlet
pipe, a water inlet
pipe, a drain
pipe, a bypass pipeline and valve groups arranged on the pipelines, the water outlet pipe is mounted at the top ends of the two filter cartridges, and the water inlet pipe is mounted at the positions, close to the bottom ends, of the two filter cartridges; the drain pipe is mounted on the bottom surfaces of the two filter cartridges, the bypass pipeline is mounted between the
tail end of the water outlet pipe and the
tail end of the water inlet pipe, and filter structures are arranged in the filter cartridges; when one filter
cartridge is allowed to be backwashed, the other filter
cartridge is allowed to continue filtering, the continuity of the production process is ensured, primary liquid
backwashing is firstly carried out, and impurities on the surface of the filter tube are taken away by utilizing the liquidity of liquid; then back flushing is carried out, and impurities embedded in pores of the filter tube are stripped by using the high-pressure characteristic of
compressed air; and finally, secondary liquid
backwashing is carried out, and impurities which are reversely blown out are flushed to a water outlet, so that the backwashing capability can be improved.