Liquid pumping system
AssigneeThe Provost, Fellows and Scholars of the College of the Holy and Undivided Trinity of Queen Elizabeth Near Dublin
InventorsIgor Shvets, Dmitri Kashanin, Vivienne Williams
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Abstract
A liquid outlet link assembly is provided for liquid delivery output rates below 10 μl per minute so as to smooth out the flow from a positive displacement pump which has an immediate step pumping rate which is relatively substantially larger than the delivery rate required through the liquid outlet means. Essentially, this liquid link assembly has a bubble of air or some other pressure activated expansion means which initially contracts on the step pump such as a syringe pump operation and then gradually expands over time, allowing a steady output rate through the link assembly.
Claims54
A liquid outlet link assembly to provide a steady liquid delivery output rate below 10 μl/minute through a liquid outlet means from a positive displacement pump having an immediate step pumping rate which is relatively substantially larger than the delivery rate through the liquid outlet means comprising:
- a body having a hollow interior;
- a liquid inlet in the body of the link assembly for connection to the pump;
- a liquid outlet in the body for connection to the liquid outlet means, said outlet means comprising a microchannel whereby a resistance to flow to the liquid outlet means is substantially greater than through the hollow interior of the body;
- and
- pressure compressible means which contracts to reduce the pressure surge of a liquid within the body when the liquid is delivered by the pump at an increased pressure through the liquid inlet, and then gradually expands to decrease the pressure drop of the liquid within the body as it is delivered through the liquid outlet, so as to maintain a substantially steady liquid pressure at the liquid outlet.
A liquid outlet link assembly to provide a steady liquid delivery output rate below 10 μl/minute through a liquid outlet means from a positive displacement pump having an immediate step pumping rate which is relatively substantially larger than the delivery rate through the liquid outlet means comprising:
- a body having a hollow interior;
- a liquid inlet in the body of the link assembly for connection to the pump;
- a liquid outlet in the body for connection to the liquid outlet means, said outlet means comprising a microchannel whereby a resistance to flow to the liquid outlet means is substantially greater than through the hollow interior of the body;
- and
- a gas bubble in the body to create a liquid pressure at the liquid outlet o provide the desired liquid delivery flow rate through the liquid outlet means.
A pump assembly to provide a steady liquid delivery output rate below 10 μl/minute comprising:
- a positive displacement pump;
- a motor to operate the pump in a stepped manner such that the pump has an immediate step pumping rate which is relatively substantially larger than the liquid delivery output rate;
- a liquid outlet means for the pump assembly;
- a liquid outlet link assembly comprising:
- a body having a hollow interior;
- a liquid inlet in the body of the link assembly for connection to the pump;
- pressure activated expansion means in the body to create a liquid pressure at the liquid outlet to provide the desired liquid delivery flow rate through the liquid outlet means.
A microchannel structure assembly for the controlled flow of small volumes of liquids comprising:
- an elongate enclosed microchannel structure having an internal bore less than 1000 μm2 cross-sectional area;
- a positive displacement pump operating in a series of steps, each step operation of the pump dispensing a volume of the order of 0.01 μl;
- a liquid outlet link assembly comprising a body having a hollow interior with a bore considerably larger than the microchannel structure bore and thus preventing a resistance to flow therethrough substantially less than through the microchannel structure;
- a liquid inlet in the body of the link assembly for connection to the pump;
- a liquid outlet in the body of the link assembly for connection to the microchannel structure;
- and
- pressure activated expansion means in the body of the link assembly to create a liquid pressure at the liquid outlet to provide the desired liquid delivery output rate from the liquid outlet means.
Dependencies are inferred from the claim text.