Venous reservoir bag with integral high-efficiency bubble removal system

A liquid-gas bubble separator comprising:

• a container having an inlet for a fluid which includes liquid and gas bubbles, an outlet and a flow channel extending between said inlet and said outlet;
• a filter element in said container positioned in said flow channel between said inlet and said outlet and dividing said flow channel into an upstream portion and a downstream portion, said upstream portion being located between said inlet and said filter element and said downstream portion being located between said filter element and said outlet, said filter element permitting the passage of liquid and inhibiting the passage of gas bubbles;
• an upstream vent located in said upstream portion and a downstream vent located in said downstream portion;
• said filter element being between the upstream vent and the downstream vent whereby gas bubbles that do not pass through said filter element can be vented through the upstream vent and any gas bubbles downstream of the filter element can be vented through the downstream vent;
• said filter element being positioned and arranged in said container so as to define a bypass passage around said filter element leading from the upstream portion to the downstream portion, said bypass passage being open to fluid flow in both directions;
• and
• said filter element being constructed and arranged so as to provide a slight negative pressure in said bypass passage and a vortex-like flow within said filter element when liquid flows therethrough so as to recirculate some of a liquid which has passed through said filter element back to said upstream portion of said flow channel when the filter element is substantially clean to essentially close the bypass passage to flow therethrough directly from said upstream portion to said downstream portion.

A liquid-gas bubble separator comprising:

• a container having an inlet for a fluid which includes liquid and a gas, an outlet and upstream and downstream vents;
• a filter element in said container between the inlet and the outlet, said filter element having upstream and downstream sides and permitting the passage of the liquid and inhibiting the passage of the gas bubbles;
• said filter element being between the upstream vent and the downstream vent whereby gas bubbles that do not pass through said filter element can be vented through the upstream vent and any gas bubbles downstream of the filter element can be vented through the downstream vent;
• a bypass passage around said filter element leading from the upstream side of the filter element to the downstream side thereof, said bypass passage being open to fluid flow in both directions when liquid is not flowing through the container;
• and
• first means for controlling the direction of passage of liquid through the bypass passage, said first means including means for directing some of the liquid which passes through the filter element through said bypass passage from the downstream side of the filter element to the upstream side of the filter element at least when the filter element is clean to essentially close the bypass passage to flow therethrough from the upstream side of the filter element to the downstream side of the filter element.

A liquid-gas bubble separator comprising:

• a container having an inlet, an outlet, and a flow channel extending between the inlet and the outlet;
• a filter element extending from one side of the flow channel only part way across the flow channel to define a bypass passage in the flow channel which bypasses the filter element, said filter element permitting the passage of liquid and inhibiting the passage of gas bubbles;
• recirculating means responsive to flow through the container when the filter element is clean for recirculating a portion of the fluid that passes through said filter element through the bypass passage in one direction so that said portion of the fluid can pass through the filter element again and the bypass passage is essentially closed by said portion of fluid to flow therethrough in a direction opposite to said one direction;
• and
• a first vent leading from the flow channel to the exterior of the container and being positioned and arranged to vent gas bubbles which do not pass through said filter element.

A liquid-gas bubble separator comprising:

• a reservoir bag having an inlet, an outlet, and a flow channel extending between the inlet and the outlet;
• a filter element extending from one side of the flow channel only part way across the flow channel to define a bypass passage in the flow channel which bypasses the filter element, said filter element permitting the passage of the liquid and inhibiting the passage of the gas bubbles;
• said inlet directing incoming fluid into the flow channel on the upstream side of the filter element;
• a first vent leading from the flow channel to the exterior of the reservoir bag and being positioned and arranged to vent gas bubbles which do not pass through the filter element;
• and
• said bypass passage being open to flow in both directions when liquid is not flowing through the reservoir bag.