US 3564726 A
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3,564,726 VACUUM DRYER FOR BACTROL WEIGHT CONTROL SYSTEM 7 Feb. 23,1971 J. NQ|T| ET AL 2 Sheets-Sheet 1 Filed Dec.
Mm A OIT T W N Cw EOG V N W H m @A ATTORNEY-S United States Patent 3,564,726 VACUUM DRYER FOR BACTROL WEIGHT CONTROL SYSTEM John M. Nociti and Anthony Giotta, New York, N.Y., assignors to Fail-child Hiller Corporation, Hagerstown, Md., a corporation of Maryland Filed Dec. 26, 1967, Ser. No. 693,291 Int. Cl. F26b 2I/06 US. Cl. 34-51 11 Claims ABSTRACT OF THE DISCLOSURE Apparatus for dehydrating the contents of a bag, said apparatus having a heating chamber including a chamber having a pressure plate for bringing the bag into contact with a heating unit when the chamber is closed and a valve responsive to the differential pressure between the interior of the bag and the chamber for controlling the venting of the eflluent vapor to a low pressure area. The apparatus also includes a valve responsive to the condition of the seal of the apparatus to prevent the atmosphere outside of the apparatus from being evacuated through the chamber to the low pressure area.
This invention relates to drying apparatus and more particularly to apparatus for drying human waste products as well as other debris to remove their liquid content.
In many applications, it is desirable to dehydrate human waste products such as feces and urine to reduce the weight of the material and also, if desired, to permitretention of the solid constituents for later laboratory analysis. The problem of the limited space available in a space vehicle prohibits the retention of such waste material except in a dried form. Although a major application for waste dehydration is in connection with space flight, drying of waste material under conditions to keep the atmosphere free of contamination is also of use in hospitals or other analytical facilities.
The present invention is directed to use with the bag disclosed in the patent application entitled Waste Collection Bag described in and claimed in the co-pending application Ser. No. 613,031 filed Ian. 31, 1967 by Nociti and Riely and assigned to the same assignee. The apparatus of the present invention includes a chamber for re ceiving the bag containing waste material. The chamber has at least one surface capable of heating the bag and its contents to evaporate the liquid from the waste and is vented to vacuum so that etlluent vapor produced by the heating can be removed. A valve is also provided which is adapted to react to excess pressure across the bag to close the vent to vacuum and to permit pressure within the chamber to equalize with the pressure in the bag. Further the apparatus also includes, when used in a spacecraft, means to prevent the accidental opening of the chamber while the chamber is vented to vacuum and consequent loss of the cabin atmosphere.
The invention will be described in greater detail below and in the drawings in which:
FIG. 1 is a perspective view partially broken away of the drying apparatus of the present invention;
FIG. 2A is a partial cross-section along lines 22 of FIG. 1 showing the valve 46 vented to vacuum;
FIG. 2B is a partial cross-section along line 22 of FIG. 1 showing the valve 46 vented to the cabin;
FIG. 3 is a cross-sectional view of the drying apparatus of FIG. 1, showing one of the chambers in an open position ready to receive a bag and one in an operating position; and
FIG. 4 is a partial cross-section along line 4-4 of FIG. 3 showing plate 40 of valve 37.
3,564,726 Patented Feb. 23, 1971 r. CC
Referring to FIGS. 1 and 3, the drying apparatus illustrated includes four individual drying chambers 10-1, 102, 10-3 and 104, each of which is similar. Fewer or more chambers can be used as desired. Each of the chambers has exterior side walls 11a, b, c and d and a bottom wall 112 which may be welded along any seam therein so as to be impervious to the passage of gases and also structurally capable of withstanding the differential pressure created by vacuum within the chamber and cabin pressure without. As shown, two chambers may have a common wall 11d. The chambers may be cast as well as stamped from sheet material in any conventional manner.
The top of each chamber is provided with a door 12 which is affixed by means of hinges 13 to side wall 11a of the chamber. Located at the top of the chamber and extending inwardly from the side walls 11a, b, c, d, is a flange 14. Flange 14 is sealed to the side Walls with an impervious seam and is provided with a flat surface on its top side for receiving a gasket 16 which is afiixed to the underside of door 12. When door 12 is in its closed position, gasket 16 rests on flange 14 and forms a seal to prevent gases from entering or leaving the chamber.
Located in communication with adjacent side walls 11c of a pair of dehydrating chambers 10 is a heat exchanger 17. The heat exchanger is substantially the same size as wall of each chamber and includes a baflle arrange ment 17a which extends the length of wall 11a and which in the embodiment shown may extend the entire length of two chambers to permit one heat exchanger to heat all four chambers. Bafiles 17a are corrugated to provide even distribution of the heating fluid. An intake line 18 (FIG. 3) located at one end of baflies 17a permits hot Water or heated vapor or gas from some portion of an external system (not shown) to enter the heat exchanger. The fluid heating medium passes upwardly along a space provided at the edge of the heat exchanger from line 18 and then passes through the baffles 17a. The cool liquid or vapor is vented through outlet 19 at the lower opposite end of the exchanger. The end of heat exchanger 17 near outlet 19 is provided with a space between the bafiies 17a and the end wall to permit complete draining of the cooled fluid.
Located interior to each of the chambers and parallel to wall 11a is a pressure plate 20 (FIG. 3) which engages a waste collection bag 21, when in place in the unit, and forces it against the heat exchanger. One form of bag 21 that may be used in connection with the apparatus of this invention is shown in FIG. 3. The bag has an impermeable outer wall 58 containing an opening 57 located on one side. A filter 56 is mounted interior to the bag and covers opening 57 to prevent loss of the solid constituent of the waste material during evaporation. Other forms of bags may be used with this apparatus having filters located in other portions of their surfaces or no filter at all. The plate 20 is biased toward the exchanger 17 by two springs 22. Each spring 22 has the end of one arm 22a fixed to the interior of Wall 11a and the end of the other arm 23 to the back of the pressure plate.
Aflixed to the side of each door 12 on the side interior of the chamber near its edge is a pair of parallel plates 24 which extend generally perpendicularly to each door and which are also generally perpendicular to heat exchanger 17. Each of the plates 24 contains a slot 25 substantially parallel to the door 12. A pin 26 aflixed to the end of each of a pair of pressure plate retractors 27in the chamber rides in the slot. Pressure plate retractors 27 which may be flat bars of a length slightly smaller than the height of a chamber are mounted on a pair of parallel arms 28 and 29 which are pivotally mounted at one of their ends 30', 31 to wall 11a of the chamber. Pressure plate retractors 27 are located so that they are between the edges of plate 20 and the end wall. Parallel arm 28 is pivotally mounted at its other end to pin 26 and arm 29 is pivotally mounted at end 32 to the retractor. When door 12 is closed arms 28 and 29 and, in turn, plate retractors 27 are cammed by pin 26 forward toward the heat exchanger 17. Upon opening of door 12 a reverse camming OCCUIS.
A pair of pins 34 permanently aflixed to the rear outside, opposite edges of pressure plate 20 engages a pair of horizontal guides 33 aifixed to opposite end walls 11b and 11d of a chamber. Guides 33 and pins 34 prevent the pressure plate from moving vertically while permitting it to move freely toward and away from the wall 11c of the chamber common to the heat exchanger 17.
When door 12 is opened the pressure plate retractors 27 are cammed toward wall 11a by arms 28 and 29 and in turn retractors 27 engage pins 34 outside of plate 20 between the plate and the side walls, drawing the pressure plate into an open position away from the heat exchanger. When door 12 is closed the retractors 27 are urged toward the heat exchanger 17 disengaging from pins 34 and permitting springs 22 to bias the pressure plate against a collection bag 21.
Affixed to the interior of wall 11a of the chamber on the side opposite heat exchanger 17 is a valve housing 35. Housing 35 is generally of tubular shape and is provided with an inwardly extending flange 36 at its end interior to the chamber. The housing is mounted in a hole 35a located in the wall of the chamber and is also provided with an exterior flange 35b which seals the hole. A valve 37 is mounted in housing 35. Valve 37 is provided with a tubular body 38 and contains a plate 40 which closes the interior end of the valve. A series of apertures 39 are circumferentially located near the closed end of tubular body 38 adjacent plate 40 (see FIG. 4). Plate 40 is also provided with a series of apertures 41 which are aligned with a similar pattern of apertures 42 in the pressure plate 20. A spring 44 biases valve 37 toward the pressure plate. The opposite end of spring 44 abuts against a plug 45 which is mounted in the end of housing 35 opposite valve 37. The inner end of valve 37 located within housing 35 contains an outwardly extending flange 43 which engages flange 36 to limit the travel of the valve toward the pressure plate 20.
Mounted on plug 45 exterior of the chamber is a control valve 46 (see FIGS. 2A and 2B). Control valve 46 contains an outer chamber 47 having a hollow space therein which is in communication with aperture 48 in plug 45. Located in the hollow space is a ball 48a which contains a passage 49 having a 90 bend in one plane. A pair of openings 50 and 51 in housing 47 are located opposite each other and 90 from aperture 48 in the same plane so that when ball '48 is in one position as shown in FIG. 2A aperture 48 is in communication with opening 51 and when the ball is rotated 90 as shown in FIG. 2B aperture 48 is in communication with opening 50. Opening 50 is vented to atmospheric pressure which in the case of a spacecraft is cabin pressure while opening 51 is vented to line 51a shown in FIG. 2 which leads to a manifold 51b and a vent line 510 to vacuum which in the case of a spacecraft will be the exterior of the vehicle.
Affixed to ball 48a is a rod 52 (see FIGS. 1 and 3) which is rotatably mounted in bracket 53 affixed to the exterior of wall 11a. Aflixed to the top end of rod 52 is a closure bar 54 which contains a handle 55 at the opposite end from rod 52. Ball 48a and closure handle 54 are arranged so that when bar 54 is generally parallel to wall 11a of the chamber permitting door 12 to open, valve 46 will be vented to the cabin as shown in FIG. 213 to permit equalization of the pressure inside and outside of the chamber to permit the chamber to be open. Valve 46 can only be vented to vacuum when closure bar '54 is located in a position over door 12 preventing the door from opening. This prevents accidental loss of 4 pressurization in the cabin of a spacecraft through vent ing of the cabin air to space through valve 46.
In operation closure bar 54 is rotated to its open position to permit valve 46 to vent the chamber to the cabin (see FIG. 3 left-hand compartment) and a bag 21 containing waste materials which are required to be dehydrated is inserted in one of the chambers between wall 110 and pressure plate 20. Opening 57 which is covered by filter 56 is aligned with pressure plate 20 so that the opening is over holes 42 as shown in FIG. 4. At this point in the sequence of operations, the pressure plate will be retracted by the pressure plate retractors 27 thereby permitting entry of the bag.
After the bag is in place door 12 is closed, thereby camming the pressure plate retractors 27 toward the heat exchanger releasing pressure plate 20' and allowing it to move against the collection bag stabilizing the bag in a vertical position and insuring positive contact between the bag and the wall 110 in contact with the heat exchanger. As the pressure plate 20 moves away from wall 11a valve 37 moves under the influence of spring 44 inwardly into the chamber exposing the circumferential valve openings 39 to the interior of the chamber. At this point in the operation with door 12 closed and the bar 54 in the position shown in the left-hand chamber in FIG. 1, valve 46 is still vented to cabin pressure so that no change in the pressurization of the chamber occurs. Closure bar 54 is then rotated into a locking position over door 12 preventing door 12 from opening. At the same time as door 12 is locked valve 46 is opened to vacuum causing a decrease in pressure within the chamber. Heated fluid or vapor is then caused to pass through heat exchanger 17 heating the contents of bag 21. Means (not shown) may be provided to automatically start the heating cycle or a valve in the inlet line 18 may be opened. As the heat is applied gases and vapors evolved by the heating process pass outwardly through bag filter 56, opening 57 and holes 41 and 42 into the chamber. Such gases will then pass through openings 39 in valve 37 and then into space through aperture 48 and lines 51a, 51b and 510.
During the course of the drying of the material which may take several hours the pressure differential between the interior and exterior of the bag may increase within bag 21 to the point where it will cause rupture of filter 56 and loss of the contents of the bag into the chamber. As pressure increases, however, bag 21 swells and forces the pressure plate 20 further away from the heat exchanger 17. At the same time plate 40 of valve 37 will also be forced within body 35 until apertures 39' are closed by flange 36. When this occurs the venting to vacuum ceases and pressure from the gases within bag 21 will fill the space of chamber 10 until the pressures inside and outside of the bag are equalized. When this occurs the springs 22 will move pressure plate 20 to once again force bag 21 against the heat exchanger permitting apertures 39 to open and the dehydrating process to resume with the vapors venting to the exterior of the chamber.
When the process of dehydration has been completed as may be indicated by a timer 15 affixed to the unit the heat flow through the heat exchanger is stopped by closure of a valve (not shown) and the gases in the unit are permitted to continue their evacuation to space. After a suitable period handle 55 is grasped and rod 52 is turned shutting the vent 46 to space and opening the chamber to the cabin atmosphere causing the pressure within the chamber to be equalized with the cabin pressure. Door 12 may then be opened and bag 21 removed and a new bag inserted. When the pressure plate is in its retracted position it will cause apertures 39 of valve 37 to be closed by flange 36 of housing 35 providing an additional safety feature to prevent loss of cabin pressure to space.
As is apparent a novel dehydration device has been disclosed particularly adapted to the dehydration of Waste materials where contamination of the area surrounding the chamber must be prevented. The device, being particularly adapted to use in spacecraft, prevents the inadvertent loss of cabin atmosphere while providing a relatively simple operational cycle.
While a preferred embodiment of the invention has been disclosed above, it will be understood that this is illustrative only, and the invention is limited solely by the appended claims.
What is claimed is:
1. A dehydrating unit for use in dehydrating the contents of a flexible bag, comprising in combination a housing having a receiving chamber for said bag, means for sealing said chamber, means for heating the contents of said bag, means for positioning said bag within said chamber with respect to said heating means, means for venting the vapor within said chamber evolved by said heating to an area of lower pressure than said chamber, means responsive to the pressure differential between the interior and exterior of said bag to control the means for venting said chamber and means responsive to the sealing of said chamber to prevent the loss of atmosphere outside of said chamber to the source of lower pressure.
2. A dehydrating unit according to claim 1 wherein the means to prevent the loss of atmosphere outside of said chamber to the source of lower pressure comprises a valve controlling the means for venting the chamber to the low pressure source, means for controlling the position of said valve, operating means for controlling the position of the valve when the chamber is sealed whereby the air outside of said chamber is prevented from venting to said low pressure source when said chamber is sealed.
3. A dehydrating unit according to claim 2 wherein said means to prevent chamber venting further includes means to equalize the pressure between the low pressure exterior to said chamber and the pressure interior of the chamber.
4. A dehydrating unit for use in dehydrating the contents of a container, comprising in combination a housing defining a chamber for receiving said container, means for sealing said chamber, means for heating the contents of said container, means for venting the gas within said chamber evolved by said heating to a source of lower pressure than said chamber, and means responsive to the pressure differential between the interior of said container and said chamber to control the means for venting the chamber.
5. A dehydrating unit as in claim 4 wherein said con- 50 tainer has an exit port and said means for venting the gas evolved comprises means in communication with the container exit port.
6. A dehydrating unit as in claim 4 wherein the container is of a construction so as to change its size in response to the said pressure differential as moisture is removed therefrom, and said means responsive to said pressure differential comprises valve means which is operated by the change in size of said container.
7. A dehydrating unit according to claim 6 wherein said valve includes a valve housing afiixed to the interior of a wall of the housing defining said chamber, a valve body having a sealed end and a plurality of apertures adjacent 5 said sealed end, said body and housing being slidably mounted with respect to each other with said sealed end toward the interior of the chamber, means for connecting said valve to said source of low pressure, and means for biasing said valve body outwardly from said valve housing to clear the apertures of said valve body 'whereby when a container is positioned with a portion thereof in contact with said valve body an increase in the differential pressure between said container and said chamber causing the container to expand in size will move the valve body to close said valve.
8. A dehydrating unit as in claim 6 wherein said container has an exit port and said means for venting the gas evolved comprises said valve means which includes means for receiving the gas evolved through the container exit port.
9. A dehydrating unit for use in dehydrating the contents of a flexible, variable size container comprising in combination a housing defining a chamber for receiving said container, means for sealing said chamber, means for heating the contents of said container, means for venting the gas within said chamber evolved by said heating to a source of lower pressure than said chamber, and means for maintaining contact between the heating means and the container when the unit is unsealed.
10. A dehydrating unit according to claim 9 further including means for disengaging said means for maintaining contact between the container and the means for heating the contents of said container when said unit is unsealed.
11. A dehydrating unit according to claim 10 wherein said means for maintaining contact and for disengaging comprises a movable pressure plate substantially parallel to the means for heating said container, means for urging said plate toward said heating means, and means responsive to the position of the chamber sealing means for urging said plate away from said heating means when said chamber is unsealed.
References Cited UNITED STATES PATENTS 906,459 12/1908 Ortiz 34-92 3,118,742 1/ 1964 Dalgleish et al 34-143XY FOREIGN PATENTS 1,091,958 11/1954 France 34-92 202,586 8/ 1923 Great Britain 34-51 FREDERICK -L. MATTESON, JR., Primary Examiner H. B. RAMEY, Assistant Examiner US. Cl. X.R. 34-242