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US 2010/0301069 A1Published application
Pump with wash flow path for washing displacement piston and seal
AssigneeIvek Corporation
InventorDouglas S. Bensley
Life of this patent
Estimating the term…
Abstract
In general, a piston-type pump includes a wash flow path that allows a wash liquid such as water to pass through to provide washing and cleaning as the pump operates. The pump may be used in precision liquid dispensing systems and particularly with liquid solutions that have a tendency to precipitate solid particulate. By washing a portion of the pump piston, the liquid solution being dispensed and any solid particulates may be carried away and removed from the pump.
Claims15
A pump for pumping a liquid, the pump comprising:
- a pump cylinder defining a passageway including a pump chamber section and a piston wash section, the pump cylinder including at least one liquid inlet and at least one liquid outlet communicating with the pump chamber section proximate a first end of the pump cylinder and a wash inlet and a wash outlet communicating with the piston wash section proximate a second end of the pump cylinder, the pump cylinder further defining a counterbore at the second end of the passageway and first and second axial wash channels extending from the wash inlet and the wash outlet, respectively, along the piston wash section to the counterbore;
- a displacement piston slidably received in the passageway at the second end of the pump cylinder, the displacement piston being slidable between the liquid inlet and outlet and the wash inlet and outlet to draw liquid into and to push liquid out of the pump chamber section;
- and
- a lip seal located at the second end of the pump cylinder for sealing against the displacement piston, wherein the wash inlet, the wash outlet, the first and second axial wash channels, and the counterbore form a wash flow path through the piston wash section that allows a wash liquid to wash the displacement piston.
1 more element
A method for pumping a liquid solution having a tendency to precipitate solid particulate, the method comprising:
- moving a valve piston in a pump cylinder between a first position allowing the liquid solution to pass in to a pump chamber section through a liquid inlet and a second position allowing the liquid solution to pass out of the pump chamber section through a liquid outlet;
- reciprocating a displacement piston in the pump cylinder to draw the liquid solution through the liquid inlet and into the pump chamber section when the valve piston is located in the first position and to expel the liquid solution through the liquid outlet when the valve piston is located in the second position;
- and
- while the displacement piston is reciprocating, passing a wash liquid into a wash inlet, through a wash flow path around a circumference of the displacement piston, and out of a wash outlet.
1 more element
Dependencies are inferred from the claim text.