A pump, a homogenizer comprising said pump and a method for pumping a liquid product
AssigneeTetra Laval Holdings & Finance S.A.
InventorsJohan STENBECK, Isac SALMAN
Life of this patent
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Abstract
The present invention relates to a membrane-based piston pump (400) for pumping a liquid product. The pump is provided with a device (426) for maintaining a pre-defined hydraulic fluid volume in the pump. The device comprises an axle element (440) and a bushing element (432). The invention further relates to a method for pumping a liquid product in a pump. Furthermore, the invention relates to a homogenizer provided with a membrane-based piston pump.
Claims22
A membrane-based piston pump for pumping a liquid product, wherein said pump is provided with a device for maintaining a pre-defined hydraulic fluid volume in the pump, said device comprises:
- a hydraulic fluid reservoir,
- a bushing element attached in a passage between a piston cavity and a membrane cavity, said bushing element having a radial opening in fluid connection with the hydraulic fluid reservoir,
- an axle element arranged such that a first axial end thereof is attached to a first membrane provided in the membrane cavity, and such that at least a portion of said axle element is journalled, and adapted for axial movement, in the bushing element,
- said axle element being provided with a first recess, wherein
- if the first membrane is displaced beyond a first operational turning point, to a point at, or in close vicinity of, a first extreme point, the first recess of the axle element is adapted to come into fluid connection with the radial opening of the bushing element, and
- if the first membrane is displaced beyond a second operational turning point, to a point between the second turning point and the second extreme point, the radial opening of the bushing element is adapted to come into fluid connection with the piston cavity or to come into fluid connection with a second recess provided in the axle element,
- thereby creating a fluid connection between the hydraulic fluid reservoir and the hydraulic fluid volume of the pump.
A method for pumping a liquid product in a pump, said pump comprising
- a hydraulic fluid reservoir,
- a bushing element attached in a passage between a piston cavity and a membrane cavity, said bushing element having a radial opening in fluid connection with the hydraulic fluid reservoir,
- an axle element arranged such that a first axial end thereof is attached to a first membrane provided in the membrane cavity, and such that at least a portion of said axle element is journalled, and adapted for axial movement, in the bushing element,
- said axle element being further provided with a first recess, wherein the method comprises the steps of
- filling a second membrane cavity portion, of the membrane cavity, with the liquid product by moving the first membrane to a first operational turning point,
- emptying the liquid product from the second membrane cavity portion by moving the first membrane to a second operational turning point,
- wherein the method further comprises the step of,
- if the first membrane is displaced beyond the first operational turning point, to a point at, or in close vicinity of, a first extreme point, creating a fluid connection between the hydraulic fluid reservoir and a hydraulic fluid volume of the pump for introducing hydraulic fluid into the pump by letting the first recess of the axle element come into fluid connection with the radial opening of the bushing element, and
- if the first membrane is displaced beyond a second operational turning point, to a point between the second operational turning point and a second extreme point, creating a fluid connection between the hydraulic fluid reservoir and the hydraulic fluid volume of the pump for discharging hydraulic fluid from the pump by providing fluid connection between the radial opening of the bushing element and the piston cavity or by providing fluid connection between the radial opening of the bushing element and a second recess provided in the axle element.
22-23. (canceled)
Dependencies are inferred from the claim text.