U.S. patent number 3,577,988 [Application Number 04/871,986] was granted by the patent office on 1971-05-11 for dual canister recirculator.
This patent grant is currently assigned to Agonic Engineering, Inc.. Invention is credited to Richard F. Jones.
United States Patent |
3,577,988 |
Jones |
May 11, 1971 |
DUAL CANISTER RECIRCULATOR
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 diver's helmet, making it easier to use the diver's 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.
Inventors: |
Jones; Richard F. (Santa
Barbara, CA) |
Assignee: |
Agonic Engineering, Inc. (Santa
Barbara, CA)
|
Family
ID: |
25358587 |
Appl.
No.: |
04/871,986 |
Filed: |
February 3, 1969 |
Current U.S.
Class: |
128/201.25;
128/201.27; 96/131 |
Current CPC
Class: |
B63C
11/24 (20130101) |
Current International
Class: |
B63C
11/24 (20060101); B63C 11/02 (20060101); A62b
007/00 (); A62b 018/04 (); B01d 027/00 () |
Field of
Search: |
;128/142.7,202,142.6,191,188,142.5,142.4,142.3,146.2
;55/68,387,388,(Gas Mask/ Digest)/ ;55/(Inquired) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
461,696 |
|
Jun 1928 |
|
DT |
|
461,873 |
|
Jun 1928 |
|
DT |
|
447,119 |
|
Nov 1935 |
|
GB |
|
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: Mitchell; J. B.
Claims
I claim:
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 opening;
c. an outlet on the other canister connected to the other enclosure
opening;
d. a rigid connection between the canisters to place them in
series;
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.
Description
This invention relates to diving equipment wherein the diver is
breathing an atmosphere that tends to accumulate carbon dioxide
expelled from the diver's 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 diver's 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 provided 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 gas 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 18 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.
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 100 pounds per square inch above
environmental pressure. The aspirator can recirculate the air in
the diver's 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 39.
The top cap 34 is removed by first unscrewing the ring nut 38 and
separating the hose from 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 illustrated 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 nozzle 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 nozzle 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. 1 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 5 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 diver's 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 18 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 diver's 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 diver's helmet, making it
easier to use the diver's microphone and earphones.
When both valve 29 on the valve block 52 and valve 12 on the
diver's 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 18 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 18 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 the recirculator 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.
* * * * *