# US 4,398,930 A · Fluid deaeration apparatus

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- Number: US 4,398,930 A
- Document ID: US4398930A
- Status: Granted
- Kind: A
- Application number: 06/297,529
- Filed: 1981-08-07
- Granted: 1983-08-16
- Earliest claimed: 1981-08-07
- Assignees: Caterpillar Tractor Co.
- Inventors: Larry A. Larson; Brian J. Murphy
- Web page: https://patentgrep.com/patent/US4398930A

## CPC

- F02M 37/0047: {Layout or arrangement of systems for feeding fuel (fuel injection apparatus characterised by their conduits and venting means F02M55/00; fuel injection apparatus having a common rail F02M63/0225; arrangement of fuel conduits of low pressure fuel injection apparatus F02M69/462)}
- B01D 19/0042: {modifying the liquid flow (B01D19/0021 takes precedence)}
- B01D 19/0063: {Regulation, control including valves and floats (for construction and details of valves F16K)}
- B01D 19/0078: {by vibration}
- F02M 37/20: characterised by means for preventing vapour lock
- F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)

## Abstract

A fluid deaeration apparatus (10) for removing gas from a circulating fluid having a closed, fluid filled tank (12) for receiving and slowing the fluid. A pressure regulating valve (52) is provided for inducing negative pressure waves in the fluid entering the tank (12) for conditioning the gas in the fluid for removal from the fluid in the tank and for collection and venting of the gas from the tank (12).

## Claims

### Claim 1

In a deaeration apparatus (10) for removing bubbles of gas from a fluid being circulated in a closed system, the improvement comprising:
a circulating pump (11);
closed tank means (12) for receiving and slowing the fluid containing gas, said tank means (12) having a fluid inlet (26) and a fluid outlet (42), said tank means (12) being filled with fluid to a level that covers said fluid inlet (26);
means (46) for positively venting gas from a gas space above said fluid in said tank means (12);
an injector pump (13) extracting a fluctuating amount of deaerated fluid from the closed system; and
pressure regulating valve means (52) for continuously inducing negative pressure waves in said fluid, said pressure regulating valve means (52) being interposed between said circulating pump (11) and said tank fluid inlet (26) and being disposed adjacent to said fluid inlet in said tank means (12), said pressure regulating valve means (52) being subjected to fluctuating pressure output from said circulating pump (11) and from said injector pump (13) causing said valve means to throttle in attempting to maintain a constant pressure, said throttling of the valve means (52) inducing said negative pressure waves in said fluid, said negative pressure waves causing dissolved gas in the fluid passing through said pressure regulating valve means (52) to oversaturate to form bubbles of entrained gas, said bubbles of entrained gas being collected and positively vented from said tank means (12) through said vent means (46).

### Claim 2 (depends on 1)

The deareation apparatus (10) of claim 1 wherein said venting means is a gas vent (46) communicating with the interior (C) of the tank means (12).

### Claim 3 (depends on 1)

In the deaeration apparatus (10) of claim 1 wherein the improvement further comprises means (28,30) for splitting the flow of fluid entering said tank means (12) to further slow said fluid.

### Claim 4

In a deaeration apparatus (10) for removing bubbles of gas from a fluid being circulated in a closed circuit, the improvement comprising:
a circulating pump (11) in the circuit discharging fluid with a fluctuating pressure output;
a closed tank (12) in the circuit having a fluid inlet (26) submerged below the surface of the fluid, and a fluid outlet (42), said tank (12) being substantially filled with fluid and receiving and slowing the flow of fluid containing said gas;
means (46) for positively venting gas from above the surface of the fluid in said tank (12); and
pressure regulating valve means (52) for receiving said fluctuating pressure output of said circulating pump (11) and continuously inducing negative pressure waves in said fluid, said pressure regulating valve means (52) being interposed between said circulating pump (11) and said tank fluid inlet (26), said negative pressure waves causing dissolved gas in the fluid passing through said pressure regulating valve means (52) to oversaturate to form bubbles of entrained gas, said fluid with the bubbles of entrained gas being slowed as it enters the tank (12) whereupon the bubbles of entrained gas are released into the space above the surface of the fluid, said bubbles of entrained gas being collected and positively vented from the space above the surface of the fluid in said tank (12) through said vent means (46).

### Claim 5 (depends on 4)

The deaeration apparatus (10) of claim 4 wherein said valve means (52) is placed adjacent to said tank (12).

### Claim 6 (depends on 4)

A deaeration apparatus (10) as claimed in claim 4 wherein said tank (12) has a dome-shaped top (14) and wherein said vent means (46) communicates with the high point of said top (14) for venting gas from said tank (12).

### Claim 7

In a deaeration apparatus (10) to remove entrained gas from a fluid circulated by a pump (11), a closed pressurized tank (12) substantially filled with fluid and having disposed therein at least one baffle (32) to slow the fluid velocity, said tank (12) having an inlet side (18) with an inlet tubing (26) passing into the tank (12) through the upper portion of the inlet side (18), at least one nozzle (30) on said inlet tubing (26), which nozzle is submerged below the surface of the fluid for directing the flow of fluid entering the tank (12), said tank (12) having an outlet side (20) with an outlet tube (40) near the bottom thereof, and said tank (12) having a top (14) with a vent (46) extending therethrough and communicating with a gas space above the surface of the fluid to remove gas from said gas space, the improvement comprising:
a pressure relief valve (52) interposed between said circulating pump (11) and said tank inlet tubing (26) and positioned adjacent to said tank (12), said pressure relief valve (52) continuously opening and closing in response to pressure variations emanating from the circulating pump (11) to create negative pressure waves in the fluid for transforming the dissolved gas in the fluid into bubbles of entrained gas, the tank (12) slowing the fluid and entrained gas to remove the bubbles of entrained gas from the fluid, said bubbles of entrained gas being collected in the gas space above the surface of the fluid in said tank (12) and being positively vented through said vent (46).