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Publication numberUS3577988 A
Publication typeGrant
Publication dateMay 11, 1971
Filing dateFeb 3, 1969
Priority dateFeb 3, 1969
Publication numberUS 3577988 A, US 3577988A, US-A-3577988, US3577988 A, US3577988A
InventorsJones Richard F
Original AssigneeAgonic Engineering Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Dual canister recirculator
US 3577988 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

United States Patent [72] Inventor Richard F. Jones Santa Barbara, Calif. [21] Appl. No. 871,986 [22] Filed Feb. 3, 1969 [45] Patented May 11, 1971 [73] Assignee Agonic Engineering, Inc.

Santa Barbara, Calif.

[54] DUAL CANISTER RECIRCULATOR 5 Claims, 4 Drawing Figs.

[52]. US. Cl 128/142.7, 55/68,128/145.5,l28/191R [51] lnt.Cl A62b 7/00, A621) 18/04, B01d 27/00 [50] Field of Search 128/142.7, 202, 142.6, 191, 188, 142.5, 142.4,142.3, 146.2; A 55/68, 387, 388, (Gas Mask Digest), (lnquired) [56] References Cited UNITED STATES PATENTS 1,561,086 11/1925 Korjibski 128/142.7(X) 3,240,567 3/ 1966 Caparre1ietal.. 23/284 FOREIGN PATENTS 461,696 6/1928 Germany 128/191 461,873 6/1928 Germany 128/191 447,119 ll/1935 Great Britain 128/191 Primary Examiner-Richard A. Gaudet Assistant ExaminerJ. B. Mitchell Aztorneyl-larry W. B'relsford ABSTRACT: The gas mixture breathed by a diver is circulated through a carbon dioxide removing chemical to eliminate the build up of carbon dioxide in the life support atmosphere. The chemical is contained in two separate tanks or canisters carried by the diver, and a gas propulsion mechanism is disposed between the two canisters. This results in sucking atmosphere through one canister and pushing it through the other, which reduces the channelling of gas in the, carbon dioxide absorber chemical. Also it isolates the sound of the gas moving mechanism so that very little noise reaches the divers helmet, making it easier to use the divers microphone and earphones. The carbon dioxide absorber is prepackaged in removable cartridges to improve the quality of the packing of the absorbing chemical and to make removal and replacement of the chemical quicker and easier.


suwznra FIG. 2



SHEET 3 OF 3 I N VEN'TOR. RICHARD F. JONES SW/6w I ATTORNEY DUAL CANISTER RECIRCULATOR This invention relates to diving equipment wherein the diver is breathing an atmosphere that tends to accumulate carbon dioxide expelled from the divers lungs. More particularly it relates to an improved mechanism wherein this atmosphere is circulated through a chemical that removes carbon dioxide, and these mechanisms are referred to in the industry as recirculators." The recirculator of the present invention is of the type carried by the diver.

It is a general object of the invention to provide an improved recirculator for the gas mixture breathed by divers for the removal of undesired gas constituents, and the described embodiment relate to removal of carbon dioxide.

Other objects, advantages and features of the invention will be apparent in the following description and claims considered together with the accompanying drawings forming an integral part of the specification in which:

FIG. 1 is a schematic view partly in section of the apparatus as attached to the divers helmet and as carried on the back of a diver.

FIG. 2 is an isometric drawing with portions broken away to show the internal construction of the recirculator unit shown schematically in FIG. 1.

FIG. 3 is an elevation view in full section of the lower part of the apparatus of FIG. 2, showing the aspirator for moving the gases inside of the recirculator.

FIG. 4 is an exploded view in three dimensions of the valve block and the attachments thereto shown in FIG. 2.

Referring to FIG. 1 there is illustrated a diver having a complete diving enclosure including a suit 1 and a helmet 2 removably secured together by means of a suitable neck band 3 which forms a watertight joint between the helmet 2 and the suit 1. The diver carries on his back a recirculator unit 4 pro-.

vided particularly in accordance with the invention, and this may be supported on his back by means of shoulder straps 6. A source of air (not shown) or other suitable mixture may deliver gas through a hose 5 to a check valve 7 and thence to a conduit 8 leading 'to the diving helmet 2, and this may be conveniently attached to the helmet at 9. This gas mixture may be channeled inside the helmet 2 by a conduit 11 which leads to a manual control valve 12. If the diver wishes to receive direct gas flow from the source, he opens the manual valve 12, and air flows through the check valve 7 up the conduits 8 and 11 and into the interior of the helmet at valve 12.

The diving helmet may also be provided with an exhaust valve 13 which automatically bleeds gas to the exterior of the diver's enclosure, whether it be water or other fluid in which the diver is operating. The exhaust valve 13 is normally present to maintain a pressure inside of the diver's suit and helmet that is above the external environmental pressure by selected amount, for example, one-half a pound per square inch.

Divers working at the greater depths are now supplied with a mixture of oxygen with other rare and sometimes expensive gases, the most common of which is helium. In order to preserve the helium and keep it from being blown out to the environment through the exhaust valve 13, the gas inside the helmet 2 is recirculated to eliminate the carbon dioxide which has been expelled by the lungs of the diver. While such units could be placed inside of the helmet, the result would be an unusually large and bulky helmet, and accordingly it is more desirable to have an external unit to scrub the air or gas inside the helmet for the removal of carbon dioxide. For this purpose the helmet is provided with a recirculator outlet port 14 and a recirculator inlet port 16. Connected to both ports 14 and 16 are flexible hoses 17 leading respectively to a canister 18 and 19, both filled with a carbon dioxide absorbing material 21. The two canisters l8 and 19 are connected at their bottom ends by means of a cross conduit 22 which is provided with a partition 23 holding a venturi 24. Gas under pressure is squirted through a small nozzle 26 at the end of a curved pipe 27 which in turn is connected through a constant pressure regulating valve 28 and a manual control valve 29 to the source of gas supplied to the diver. This gas is received from the check valve 7 by means of a branch conduit 31 from the pipe 8.

The operation of the device of FIG. 1 is alternative: that is, the diver may operate by a direct supply through the conduit 8 and the manual valve 12, or he may operate by gas delivered to the nozzle 26 forming part of an aspirator. When the diver desires to operate directly on the gas supply line 8, the manual valve 29 to the recirculator 4 is closed, and the manual valve 12 on the helmet is opened. The gas mixture then flows directly into the helmet, and the surplus gas is blown off through the exhaust valve'13.

When it is desired to save part of the helium or other gas present in the gas mixture fed to the diver, the direct line is closed off and the recirculator operated so that carbon dioxide will be scrubbed out of the gas mixture. This is accomplished by manually closing the helmet valve 12 opening the manual valve 29 to the recirculator. Gas then flows through the branch conduit 31, through the valve 29, through the constant pressure valve 28, into the conduit 27 and thence out of the nozzle 26 which together with the venturi 24 forms an efficient aspirator. The gas surrounding the nozzle 26, accordingly, is driven through the venturi 24 by the aspirator action, and this causes a suction in the canister 18 indicated by the direction of the arrow 20. The aspirator also causes a pressure in the bottom of canister 19, causing an upward flow' of gas as indicated by the arrow 32. i

The gas fed in at the aspirator nozzle 26 is the desired mixture of oxygen with the other gas, and this may be of a relatively high pressure, for example, 50 or pounds per square inch above environmental pressure. The aspirator can recirculate the air in the divers helmet as many as 20 times per minute, resulting in very efficient scrubbing, so that the residual carbon dioxide is as low as one-half of one percent, even when the diver is working hard.

Reference is now made to FIGS. 2, 3 and 4 for the details of construction of a presently preferred form of a commercial unit. Referring first to FIG. 2, there it will be noted that the canisters 18 and 19 are joined together by the cylindrical connection 22 at the bottom, but there is also provided a top bridge member 32 which has a pin 33 around which may be wrapped the shoulder straps 6 shown in FIG. 1. The tops of canisters 18 and 19 have a threaded top cap 34 from which projects a nipple 36 to which is connected a hose nipple 37 by means of a ring nut 38. The flexible hoses 17 are connected to the hose nipples 37 in any suitable manner, as by hose clamps The top cap 34 is removed by first unscrewing the ring nut 38 and separating the hosefrom the canisters 18 and 19, and thereupon the tops 34 are manually unscrewed. This makes accessible a cartridge 41 in which is held the material 21 which absorbs carbon dioxide. The cartridges 41 are provided particularly in accordance with the invention, and presently it is preferred to form them entirely of plastic. Tubular plastic may form the sidewalls and specially molded plastic may form the top 42 and the bottom 43. The bottom 43 may be cemented in place and the top wall 42 may be threaded into engagement with the tubular sidewall. Both the bottom 43 and the top 42 have screens formed therein having a mesh opening that is smaller than the granule size of the carbon dioxide absorbent. For example, the carbon dioxide absorbent presently being used is in the form of kernels about the size of wheat, and the openings molded into the top and bottom 42 and 43 are about one-sixteenth of an inch square. The plastic cartridge makes a tight fit inside the canister 18 so that all gas flow is through the apertured ends 42 and 43. If desired, the canister top can press the cartridge against a low ring stop 45 to prevent bypassing of the granular material 21.

The use of cartridges has several advantages. In the first place they are loaded when they are outside of the canisters 18 and 19, and hence may be carefully packed so that they are completely full. Thereafter when the diver works in various positions, sometimes in an upside down position, the absorbent material 21 will not shift, and accordingly does not open up air passages that allow free gas flow out of contact with the absorber. Another advantage is the ease of removal of spent absorber and the replacement of fresh absorber, preferably in spare cartridges that have been previously filled. A definite time saving results from the use of cartridges as heretofore it has been necessary to turn the entire recirculator upside down, tap and shake it to remove spent absorber from the canisters, and frequently flushing with water has been used. Such steps are unnecessary with my cartridge operations.

The forming of cartridges of plastic gives the absorber thermal insulation from the canisters 18 and 19 which are preferably formed of metal. The water in which divers operate is usually quite cold, and this chills the absorber, reducing its chemical efficiency. The plastic sidewall provides effective thermal insulation against such cooling.

The cartridges permit careful packing of the carbon dioxide removing chemical. In order to avoid channelling, it is desirable to vibrate the canister or cartridge while it is being filled with the chemical which is usually in grandular form. It is difficult to vibrate an entire recirculator pack, but much easier to vibrate a removable cartridge. It is easier to see when the material has completely filled the container which retains it, and this tight packing of the material is necessary to prevent shifting during working by the diver.

The construction of the aspirator which moves the carbon dioxide laden gas through the extracting chemical is best illus trated in FIGS. 2 and 3. There it will be noted that the parts previously identified in FIG. 1 are indicated by the same reference numerals. The tube 22 connecting the bottoms of the two canisters 18 and 19 is shown, together with the partition 23 secured therein as by welding or soldering. The venturi 24 butts against one end of the partition 23 and a nozzle support 44 is threaded on to the venturi 24 to hold it in position. The left end of the nonle support 44 as viewed in FIGS. 2 and 3 is drilled to receive a nozzle bushing 46 into which the nozzle member 26 is threaded, and a coupling nut 47 secures the inlet conduit 27 to the nozzle member 26.

The noule support 44 is apertured on each side of the nozzle 26 to permit free entry of gas from the bottom of canister 18 to the interior of the venturi 24. The inlet conduit 27 has an airtight joint with the canister 28 by any suitable means, such as a gland 48 though which the conduit 27 passes and which is engaged by a tubular nut 49 which holds a conduit 51 leading to the pressure regulator valve 28.

Referring to FIGS. 2 and 4, there is illustrated a valve block 52 to which are attached several conduits and valves. This block is preferably formed of metal and soldered to the canister 19 or to the transverse tube 22 or to both. This is a mechanically strong connection so that considerable force can be exerted on the valve block 52 if this is required. The valve block 52 has an inlet bore 53 which branches in the interior of the block into the recirculator conduit 31 identified in FIG. 1 and to the direct air supply branch 8a identified in FIG. I as conduit 8. Check valve 7 is threaded into the inlet bore 53 and a coupling 54 is connected thereto for suitably holding the inlet hose 5. The branch passage 8a inside of the block terminates in a vertical bore 56 into which is threaded a fitting 57 to which is secured the hose 8. Thus free uninterrupted flow is established from the hose through the check valve 7 to the hose 8 connected to the top of the block 52.

The branch passageway 31 ends at a counter bore 58, the bottom of which forms a valve seat which may be closed off by threading a suitable valve face against the bottom of the counterbore 58. Accordingly, the valve body 29 is threaded into the counterbore 58, and a manually rotatable handle 29a actuates the valve.

Leading from the bottom of the counterbore 58 is a diagonal passage 59 leading to a vertical bore 61 which is internally threaded so that the pressure regulating valve 28 may be threaded into it. A suitable tube fitting 62 is threaded to the outlet of the pressure regulating valve 28 to connect to one end of the tube 51 which delivers gas mixture to the aspirator as previously described.

The operation of the mechanism of FIGS. 2, 3 and 4 is similar to that of FIG. 1 but will be described with reference to the specific mechanisms of these FIGS. 2, 3 and 4. A gas mixture under pressure enters the tube 5 and passes through the check valve 7 to the interior of the valve block 52. The branch passageway 8a delivers this gas under pressure to the fitting 57 which is connected to the hose 8, which in turn is connected directly to the divers helmet at 9 as shown in FIG. 1. The diver can stop the flow of gas through this passageway 8a and the tube 8 by closing the manual valve 12 on his helmet, as explained with reference to FIG. 1.

The other branch 31 is controlled by the manual valve 29,

and when this valve is opened gas flows through the passage 31 into the passage 59, and thence through the vertical bore 61 to the pressure regulator valve 28. Its output is delivered through the fitting 62 to the pipe or conduit 51 to the aspirator conduit 27 where it emerges from the aspirator nozzle 26 to blow into the venturi 24. This gas flow causes a pumping or aspirator action to move gas from the interior of the bottom end of the canister 18 to the interior of the bottom end of canister 19.

A suitable fairing 65 is removably fastened over the valve block 52, and the piping between canisters l8 and 19 to avoid snagging any of this mechanism while the diver works. This fairing 65 may be secured in any desired fashion, as to flanges 66 on the canisters.

The aspirator causes a suction to occur at the bottom end of 43 of the cartridge 41 containing the carbon dioxide absorbing chemical, thus drawing air through this chemical from the helmet via the flexible tube 17 as described in connection with FIG. 1. The positive pressure of the gas at the bottom of the canister 19 causes the gas to flow upwardly through the screened bottom 43 of the cartridge 41 and hence back to the divers helmet through the flexible tube 17 as described in connection with FIG. 1.

Placing the aspirator between the two canisters results in sucking atmosphere through one canister and pushing it through the other, which reduces the channeling of gas in the carbon dioxide absorber chemical. Also, it isolates the sound of the gas-moving mechanism so that very little noise reaches the divers helmet, making it easier to use the divers microphone and earphones.

When both valve 29 on the valve block 52 and valve 12 on the divers helmet 2 are closed, no air or gas arrives at all to the diver. The diver can, however, breathe the atmosphere with his helmet and within his inflated suit for a matter of many minutes, thus acting as a safety in the event that the hose 5 supplying gas mixture is cut or otherwise closed off. The diver, accordingly, can block the entrance of sea water to his helmet and the diving suit by closing valve 29 and valve 12.

In the event of a leak in the hoses 17 connecting the helmet 2 to the canisters l8 and 19 (FIG. 1) water will collect in the canister and may be blown by the aspirator to the interior of the helmet. In this event manual valve 29 in the valve block 52 is closed, thus stopping the aspirator and keeping the liquid inside of the canisters l8 and 19. The diver thereupon opens manual valve 12, so that he is on a direct line with the incoming gas. The action of some carbon dioxide absorbing chemicals also creates water, and this may be an additional reason for closing valve 29. The valve 29 is conveniently located where the diver can reach around to his back and manually operate this valve. The strong connection of the hose 8 to the valve block 52 and to the helmet 2 is provided particularly in accordance with the invention. This permits the diver to pick up the helmet 2 in his hands and have the recirculator 4 stay connected to it so that the recirculator 4 is in position on his back. when his helmet is in place on the diving suit. The large diameter flexible conduit 17 connecting the recirculator to the helmet are usually not strong enough to hold the weight of the recirculator and assure freedom from leakage. The hose 8, accordingly, serves a double purpose of a direct supply of gas to the diver and as a mechanical connector between the helmet and the recirculator. In this fashion the diver can completely dress or undress himself with this recirculator connected, there being no need to disconnect therecirculator from the helmet in order for the diver to place the helmet over his head or remove the helmet from his head.

The use of recirculators is an'important economy in deep water diving inasmuch as helium is the presently used mixture gas with the oxygen and is quite expensive. Up to 7 times as much gas may be needed for a working diver without recirculator as one with a recirculator. The fact that any gas must be added at all when a recirculator is used, is the current practice of bleeding gas from the helmet at all times. The aspirator spaced between the canisters also adds a mixing function in the event that there is any channelizing in the first canister. This untreated gas is mixed at the aspirator with treated gas as well as fresh gas due to the turbulence created at the exit end of the aspirator. This is enhanced by the right angle turn that the gas must make leaving the aspirator.

. It will be appreciated by those skilled in the art that the present invention may be used with a diving helmet only, sealed at the neck or shoulders. More conventionally it will be used with a watertight suit to which the helmet is connected with a watertight joint. In this latter case it is obvious that the output of the recirculator could discharge directly into the suit below the helmet or the suction could be in the suit, as long as there is gas circulation past or near the face of the diver. There is no term used in the industry to describe this watertight envelope or enclosure of suit and helmet, and accordingly, it is referred to in the description and claims as a diver's enclosure.

The invention has been described with reference to a presently preferred embodiment as required by the rules. It is not limited to this embodiment and various modifications and variations are included within the scope of the following claims.


1. In a diving system including a diver's enclosure having a pair of spaced recirculating openings, the combination with said enclosure of a recirculator for the removal of undesired constituents in the breathing atmosphere inside the enclosure comprising:

a. a pair of canisters for the retention of absorbing material for a selected gas;

b. an inlet on one canister connected to one enclosure openc. an outlet on the other canister connected to the other enclosure opening;

d. a rigid connection between the canisters to place them in series; Y

e. and pump means disposed in the connection for moving gas in one direction, whereby the atmosphere inside the enclosure may be drawn through one canister, and the drawn gas blown through the other canister to thereby remove unwanted gas constituents.

2. The combination of claim 1 wherein the pump means for moving the gas is an aspirator.

3. The device of claim 1 wherein the canisters hold a removable cartridge of gas absorbing material and the cartridges have an airtight fit in the canisters, and the sidewalls are formed of insulating material.

4. The combination of:

a. a diver's helmet having two recirculating openings, a

direct line inlet, and a valve to control direct line flow;

b. a body pack comprising a pair of canisters each having an opening, a connection placing them in series with respect to the canister openings, an aspirator in the connection to move gas in one direction through the canisters; and a valve assembly mechanically connected to the canisters having an inlet for fresh gas, a branch having free flow for the helmet and a branch having controlled flow to the body pack aspirator;

c. conduits connected one to each helmet recirculator opening and to the respective canister openings to complete a recirculation circuit, and one connected to the valve free flow branch to the helmet direct line inlet;

d. and a mechanically strong connection from the pack to the helmet whereby the body pack may be mechanically lifted by the strong connection so that the helmet may at all times remain connected to the pack for quick removal of the helmet or replacement of the helmet on the diver's head.

5. The combination of claim 4 wherein the mechanically strong connection is the conduit connecting the free flow valve branch to the helmet.

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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3707965 *Oct 22, 1970Jan 2, 1973Guzay CCarbon dioxide absorber apparatus
US3710553 *Jan 28, 1970Jan 16, 1973Biomarine IndustriesCarbon dioxide scrubber and breathing diaphragm assembly for diving apparatus
US3867936 *Jan 11, 1974Feb 25, 1975Shirley Aldred & Co LtdAnaesthetic gas safety equipment
US3973562 *Jul 29, 1974Aug 10, 1976David Guild JanssonMulti-user extended operation respirator
US3976063 *Sep 16, 1974Aug 24, 1976The Bendix CorporationEscape breathing apparatus
US4064875 *Jul 2, 1976Dec 27, 1977The Bendix CorporationAnti-suffocation means for aircraft breathing mask
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US5113854 *Jan 25, 1990May 19, 1992Figgie International, Inc.Quick-donning protective hood assembly
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US5964221 *Oct 23, 1996Oct 12, 1999Gore Enterprise Holdings, Inc.Rebreather adsorbent system
US6797043Oct 3, 2002Sep 28, 2004Hamilton SundstrandEncapsulated CO2 H2O sorbent
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US7815721 *Dec 26, 2007Oct 19, 2010Nuctech Company LimitedGas filtering-buffering device
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US20080155946 *Dec 26, 2007Jul 3, 2008Nuctech Company LimitedGas Filtering-Buffering Device
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US20140358080 *Dec 14, 2012Dec 4, 2014Cork Institute Of TechnologyBubble entrapment device with variable volume
US20150202472 *Jan 12, 2015Jul 23, 2015Bertil R.L. WerjefeltOxygen supply with carbon dioxide scrubber for emergency use
EP1407817A1 *Oct 2, 2003Apr 14, 2004Hamilton Sundstrand CorporationEncapsulated CO2 H2O sorbent
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U.S. Classification128/201.25, 128/201.27, 96/131
International ClassificationB63C11/24
Cooperative ClassificationB63C11/24
European ClassificationB63C11/24