Liquid ring pump employing discharged pumping liquid for discharge port control

Claim 1

In a liquid ring pump having a bladed rotor eccentrically mounted for rotation in an annular housing supplied with a quantity of pumping liquid, the rotor producing an annular ring of circulating pumping liquid in the housing when rotated and cooperating with the ring of pumping liquid to convey gas from an intake zone to a compression zone having a higher pressure than the intake zone, the improvement comprising: a first discharge port portion in the housing communicating with a first relatively low pressure portion of the compression zone; a second discharge port portion in the housing communicating with a second relatively high pressure portion of the compression zone; a discharge chamber communicating with the first and second discharge port portions for directing a flow of pumping liquid discharged from the second discharge port portion transversely over the first discharge port portion to substantially prevent gas from entering the compression zone via the first discharge port portion when the pressure in the first portion of the compression zone is less than the gas pressure in the discharge chamber, the discharge chamber being shaped to make use of the kinetic energy of the pumping liquid discharged from the second discharge port portion to induce a substantially continuous recirculation of pumping liquid in the discharge chamber, the path of recirculation being (1) circumferentially away from the second discharge port portion in the direction of rotor rotation, (2) radially outward from the second discharge port portion and circumferentially in the direction opposite the direction of rotor rotation, (3) radially inward after passing both the second and first discharge port portions, and (4) circumferentially over the first discharge port portion in the direction of rotor rotation; baffle means disposed in the discharge chamber for promoting recirculation of the pumping liquid in the discharge chamber; and a gas discharge outlet communicating with a portion of the discharge chamber bounded by the recirculating pumping liquid for allowing gas to exit from the discharge chamber without interfering with the recirculation of pumping liquid in the discharge chamber.