US3538892A - Hot water system - Google Patents

Description

United States Patent 2,923,480 2/1960 Christian 122/17X 3,140,740 7/1964 LaGreid et al. l26/93X 3,437,086 4/1969 Phillip 126/85 FOREIGN PATENTS 5,882 1909 Great Britain 122/177 Primary Examiner Kenneth W. Sprague Attorney-Delio and Montgomery ABSTRACT: This disclosure relates to a hand portable pres surized hot water system including self-contained heat and pressure sources. The apparatus generally comprises a housing defining a liquid reservoir and a substantially central flue vertically therethrough. A plurality of lateral tubes extend substantially diametrically across the flue in liquid communication with the reservoir. A heat source is positioned below the flue and heat energy emanating therefrom travels up the flue impinging on the lateral tubes heating the liquid therein and producing resulting convection flow of liquid through the reservoir.

nor WATER SYSTEM SPECIFICATION This invention relates to an improved portable hot water source, and more particularly relates to a new and improved portable shower system.

This invention provides a new and improved portable hot water system which includes self-contained heating and pressure sources to heat a volume of water to a predetmined temperature, and then provide pressure on such volume of water so that the water may be utilized in a shower or other type of spray or stream. A unit embodying the invention has great facility and may be easily stored, hand transported and rapidly set up for use merely by filling the reservoir with water, heating the water to a predetermined temperature, and applying pressure to the water in the reservoir.

Apparatus embodying the invention provides a truly hand portable pressurized hot water system and may be utilized by campers, sportsmen, boating enthusiasts, hunters and, also, for washing domestic pets and in other applications-where a heated and pressurized source of water is desired and no heated and pressurized water is available.

It is believed that the absence of the availability of anysuch device at the present time is primarily due to a lack of efficiency in heating at least a minimum quantity of water. Such lack of efficiency is believed due to any one of several factors including the time element involved in such heating and the amount of fuel required in heretofore proposed systems. Additionally, a limitation on such heretofore proposed systems is the lack of efficient pressure regulation of an unregulated pressurized source.

Accordingly, the present invention provides a new and improved hot water system which includes a reservoir for water, a source of heat disposed beneath said reservoir and a new and improved heat exchanger integral with said reservoir. Apparatus embodying the invention is further arranged to include a containerized source of fuel adapted to be connected to a burner, and a containerized source of pressure. The invention further includes new and improved means for regulating or reducing the pressure of an unregulated pressure source to apply and maintain a predetermined pressure on the water in the reservoir. The invention further provides a new and improved means for igniting a gas burner which is located within the confines of the unit.

Accordingly, an object of this invention is to provide a new and improved portable hot water system.

A further object of this invention is to provide a new and improved heat exchanger for heating a contained volume of liquid.

Another object of this invention is to provide a new and improved pressure reducing or regulating valve for a device of the type described.

A further object of this invention is to provide a new and improved apparatus for igniting a gas burner which is located within the confines ofa unit of the type described.

Briefly stated, the invention in one form thereof comprises a housing defining a liquid reservoir and further defining a vertically extending flue through said housing. A plurality oflateral tubes extend across said flue and communicate on opposite sides of said flue with the reservoir. A heating source is disposed beneath the flue with the laterals so positioned across the flue that they efficiently intercept the heat moving upwardly through said flue. The apparatus further includes mounting means for a containerized source of combustible gas and means for connecting such container to the burner, mounting means for a containerized source of pressure which is adapted to pressurize water in the reservoir and a new and improved lighting means for igniting gas supplied to said burner, and further includes a new and improved pressure regulating valve.

The features of the invention which are believed to be novel are particularly set forth and definitely claimed in the conobjects and advantages thereof, may best be appreciated by reference to the following detailed description taken in conjunction with the drawings, in which:

FIG. 1 is a front elevation of apparatus embodying the invention;

FIG. 2 is a top plan view of the apparatus of FIG. 1;

FIG. 3 is a vertical cross-sectional view of the apparatus of FIG. I seen in the plane oflines 3-3 of FIG. 1;

FIG. 4 is a sectional view seen in the plane of lines 4-4 of FIG. 3;

FIG. 5 is an enlarged sectional view, partially cut away, seen in the plane of lines 5-5 of FIG. 3;

FIG. 6 is a cross-sectional view of the valve shown in FIGS. 1 and 2; and

FIG. 7 is a diagrammatic view illustrating the angular relationship of heat exchanger tubes in the flue of the device shown in FIGS. 1-3.

Apparatus embodying the invention is generally indicated by the reference numeral 10 and comprises a housing member 11 having front, back, and side walls at 12, 13 and 14, respectively. The vertical walls may be extended, or be mounted ona stand below a bottom wall 15, to provide a base 16 to elevate housing 11. The base 16 in the form shown is provided with a plurality of apertures 17 to provide circulation of air beneath housing 11. The housing is closedby a top wall 18. A carrying handle 11a is pivotally mounted to the top wall 18.

In a preferred form of the invention, the front vertical side edges of housing 11 are formed concave as shown most clearly in FIG. 2 to provide recesses generally indicated at 19 and 20. Mounted to housing 11 in recess 19 is a bracket 21 which holds a pressure reducing or regulating valve 22. Mounted to housing 11 in recess 20 is a bracket 23 having an upright portion 24 which receives in a slot therein (not shown) an extension 25 in the form of a headed stud from cap 26 of a valve 27. Valve 27 is of the hand-operated type and receives therein a container 28 of combustible gas. Valve 27 is preferably provided with a stop in the ON position to allow a predetermined flow of gas from container. 28. A suitable cylinder is a readily available propane fuel cylinder, Model No. TX9 marketed by the Bernzomatic Corporation of Rochester, NY. The valve 27 in the head thereof may be tapped and drilled to receive headed stud 25 which is received in bracket 23. A flexible hose 29 leads from valve 27 and has a bayonnet type coupling 30 thereon which is received in a female receptacle 31 therefor carried by the backwall of base 16. Receptacle 31 couples to a tube 32 which leads to a burner assembly 33 hereinafter described.

The container 28 may further be secured to the housing by means of a spring 34. attached at either end thereof to a bracket 35 carried on the housing. Bracket 23 is provided with a portion defining a recess 23a for purposes hereinafter described.

A conduit 36 including a manually operated valve 37 leads to valve 22. Conduit 37 attaches to a container 38 of a source of pressure. A suitable pressure source has been found to be a IS-ounce can of dichlorodifluoromethane marketed under the trademark Falcon by the Danforth/White Division of the Eastern Company, Portland, Maine. As will hereinafter be more fully described, the above-designated propane gas cartridge and pressure source will furnish approximately a 5-minute shower utilizing more than 2 gallons of water, 18 to 20 times.

The outlet port of valve 22 is connected by a conduit 39 to an inlet 40 atop housing 11. When pressure is to be applied to the water in housing 11, valve 37 is opened and the unregulated pressure in container 38 is reduced and regulated by valve 22 and applied to the interior of housing 11 at a pressure of approximately 4% pounds per square inch above atmospheric. A water temperature sensing device 40a is providedwhich may be of the bimetallic battery-operated type. This temperature sensing unit is preferably of the type designed to emit an audible signal when the water reaches a predetermined temperature. Basically, such temperature sensor comprises a bimetallic element responsive to the temperature of the water which closes a battery-operated circuit when the desired temperature is reached. However, any audible or visual temperature sensing device may be utilized. A tube 41, preferably of transparent plastic, is connected to an outlet 42 adjacent the bottom of housing 11 and has connected to the other end thereof a shower head 43 which may have attached thereto a small hook 43a. Tube 41 is preferably of clear material in order that it can be used as a sight gage when filling the reservoir defined by housing 11. For this purpose tube 41' is inserted in recess 23a in bracket 23. Tube 41 has a sliding fit on a sleeve extending from outlet 42 and this connection serves as a pressure relief valve.

A port 44 is defined in the top of top wall 14 of housing 11 to allow the reservoir therein to be filled with water. The port 44 receives an air tight closure plug which is illustrated as a plug 45 having a fine thread.

A heat exchange is formed integral with housing 11.

A column or flue 46 extends vertically through housing 11. A plurality of lateral or heat exchange tubes 46 a are disposed essentially diametrically across flue or column 46 in an arrangement to most efficiently intercept the heat from burner 33 traveling upwardly through flue 46, as will hereinafter be more fully described.

The burner 33 (FIG. 4) may be of a commercially available type which includes a perforate cylindrical side wall 48 joined by an imperforate top and bottom wall 49 and 50, respectively. The lead-in tube 32 extends upwardly through bottom wall 50 and is held in fixed relation to the burner assembly by means ofsupport member 51 and nuts 52 and 53.

Normally, when a gas burner is utilized in an open environment, flame may be produced merely by opening the valve 27 of the propane cylinder and holding a match to the side walls 48. However, in this environment the burner will not normally ignite when positioned beneath flue 46. This is due to the fact that when the reservoir defined by housing 11 is filled with water, such water is almost always cold, on the order of 45 if taken from a well. The cold water produces a down draft through flue 46 and prevents ignition of the gas. I have found that this problem may be overcome by inserting a tube 54 (FIG. 3) through the front wall of base member 16 and extending into gas outlet 55. Tube 54 at the inner end thereof is provided with an opening 56 which is offset with respect to the axis of tube 32 so that the gas traveling through tube 32 will enter tube 54 substantially tangentially and spiral out along the length thereof at high velocity toward openings 58 and 59 disposed adjacent perforate side wall 48. Openings 58 and 59 are upwardly disposed and substantially 90 apart. As the gas moves through tube 54 at high velocity, some gas escapes through openings 58 and 59 at the side wall of burner 33.

When a flame is applied to the open end of tube 57 under such conditions, the gas will ignite and back burn to openings 58 and 59 and a pilot flame will appear at either or both of openings 58 and 59. The flame at openings 58 and 59 will ignite the gas through the perforations in side wall 48 and provide a circular flame around side wall 48. The heat from burner 33 will then travel in a spiral path up flue 46 and impinge on and flow around laterals or heat exchanger tubes 46a, and also transfer heat through the side walls defining flue 46.

To operate the disclosed shower system, the tube 29 from valve 27 is connected to tube 32 leading to burner 33. The valve 27 is opened and flame is applied to the end 57 of tube 54, and the gas passing through perforate wall 48 is ignited. This produces an updraft of the heat from burner 33 through flue 46 which rises in a spiral. The water in the tubes 46a are therefore heated by the gases and heat traveling up the flue and by convection the water in the reservoir defined by housing 11 will pass through the various tubes 46a and heat the water in housing 11.

When the water has been heated to the desired temperature, valve 27 is closed extinguishing the flame from burner 33, the shower head 43 is positioned and manual valve 37 is opened to place pressure on the water in the tank. During the heating of the water, the hotter water will move to the top of the tank and there will be a several degree differential in the temperature of the water along the top of the tank. The sensor 40a is positioned towards the lower part of housing 11 and is preferably set for about At this time, it is found that the temperature at the top of a tank of approximately l2-inch height will be approximately As the water is drawn off from the bottom of the tank under pressure this difference in temperature between the higher and lower levels of water will compensate for any heat loss after the heat is removed.

It has been found that the apparatus functions satisfactorily with as little as 4 and V2 pounds per square inch of pressure above atmospheric within housing 11. To maintain this or any other predetermined pressure within housing 11 a pressure reducing and regulating valve 22 is provided.

Valve 22 comprises a generally cylindrical housing 62 having top and bottom closure members 63 and 64, respectively. An inlet port 65 is defined in the bottom thereof which is in communication with line 66 on the downstream side of valve 37. The conduit 66 is preferably threadably received into bottom wall member 64. Housing 62 and a valve closure portion 67 define an annular chamber 68 about a valve seat 69, and in communication with a central chamber 70 which leads to an outlet port 71, Outlet port 71 receives an adaptor 72 therein for connection to line 39. Outlet port 71 is in continuous communication with the lower portion 73 of an upper chamber 74 by means of a sensing passage 75. A valve stem 76 extends from chamber 68 through chamber 70 and into chamber 74. At the lower portion of valve stem 76 closure portion 67 carries a resilient disc 77 thereon adapted to contact valve seat 69 and block communication between chambers 68 and 70. Valve stem 76 is biased upwardly by a spring 78 seated in socket 79. Disposed between housing member 62 and an end wall 63, and dividing chamber 74 into two parts is a diaphragm 80. Seated on the upper end of valve stem 76 through diaphragm 80, and acting against end wall 63 is a spring 81 which is seated at the lower end thereof in a washer 82. Spring 81 bears against an integral flange on an adjustment screw 83 at the upper end thereof. Spring 81 is selected to have a spring constant such that it will hold the valve closure member 67 open against high pressure input from conduit 66. The upper portion of chamber 74 is ported to the atmosphere at 84. Only sliding clearance is required between the valve stem 76 and the valve body.

in operation, under normal conditions, spring 81 will depress valve stem 76 from the position illustrated and allow communication from chamber 68 to chamber 70 and outlet port 71. The pressure in outlet port 71 is communicated to the lower portion 73 of chamber 74 through passage 75 and when this pressure exceeds a predetermined value it will overcome, together with the bias of spring 78, the bias of spring 81 and close the valve. Thereafter, as the pressure in port 71 falls below said predetermined value, the bias of spring 81 will open the valve and allow the pressure to build up until said predetermined pressure is again reached. In this way, the valve opens and closes to regulate the pressure in port 71 and, hence, the pressure on the water in the reservoir defined by housing 11, to a constant value. In practice, it is desired to maintain the pressure at essentially 4 to 4 V2 pounds.

The valve as described above may be as small as three'quarters of an inch in length and a half inch in diameter and has operated very well with pounds input adjusted to four pounds output. Screw 83 allows the bias of spring 71 to adjust the output pressure and to compensate for any wear, age of the parts, etc.

I have found that certain considerations in the design of the heat exchanger provide more efficient utilization of heat and resultant heating of water in the housing 11.

The diameter of burner 33 is selected to be slightly less than the diameter of flue 46. Then essentially all heat energy generated by the combustion of gases at burner 33 travels upwardly, and little if any energy is wasted or inefficiently used in heating the bottom of the housing.

A further consideration is that the heated air traveling up flue 46 defines a generally spiral path which is in the form of a cylinder. This spiral path has a vertical dimension through 360 of the spiral. This vertical dimension H is primarily a function of the rate of fuel consumption at burner 33 and, hence, a function of the heat energy released at burner 33. The dimension H will further beinfluenced by the diameter of burner 33 and the diameter and height of flue 46.

An increment of distance dH will decrease with an increment of spiral angle d5 as the heat moves up the flue. However, for purposes of explanation, the heat spiral may be stated to have a pitch P of 0 H degrees/inch of rise It is apparent that the dimension H can accommodate a maximum number N of laterals of outside diameter L, the

number being Where D is the inside diameter of the flue, and

L is the outside diameter of the laterals.

Assume for example that the following dimensions are chosen The circumference of the flue is lf ten laterals ofL 0.5 inches are used, this will provide ten inches of utilization of the circumference and H/L I.

This will leave 0.5 inches for spacing between ten laterals or approximately 0.05 inches. This gives a center-to-center dimension C of 0.55 inches between laterals.

Since the pitch P of the spiral the angular displacement A between successive laterals, if the laterals are to follow the heat spiral will be However, if the angular array of laterals exactly follows the spiral of heat, there may be loss ofheat up the flue.

Accordingly, for efficient interception of the heat by the laterals, I arrange the laterals in the given numerical example in successive pairs with each lateral of a pair displaced by 90- A" or 54 apart, as shown in FIG. 7 where the angle A between laterals 101 and 102 is 54. The third lowest lateral 103 is then disposed at 90 with respect to lateral 102, and lateral 104 is disposed at the angle A with respect to lateral 103.

Successive pairs of laterals 105, 106; 107, 108; and 109, 110 are similarly arranged. The direction of the'displacement angle A is continuous and depends on the geographical area of usage. In the Northern Hemisphere, the direction is counterclockwise, while in the Southern Hemisphere, the direction is clockwise due to the polarities of the earth.

The numerical example set forth above is given solely for exemplary purposes. It may occur that the spiral height and number of laterals do not terminate evenly as set forth in the example. lfin the example the flue height were 1 1 inches, two complete sets of laterals 101-110 would be utilized. Where possible and practical, two or more complete sets of laterals per spiral dimension H would be quite efficient.

Accordingly, the many factors which enter into design of the heat exchanger may demand compromise in certain instances to achieve most efficient heat transfer consistent with allowable dimensions. A presently preferred embodiment of the invention has been set forth for purposes of disclosure which includes many features capable of modification and different embodiment in equivalent structures.

From the foregoing it may be seen that the objects of the invention set forth as well as those made apparent are efficiently attained. While preferred embodiments of the invention have been set forth for purposes of disclosure other embodiments of the invention as well as modifications to the disclosed embodiment which do not depart from the scope of the invention may occur to others skilled in the art. Accordingly, the appended claims are intended to cover all embodiments and modifications of the invention which do not depart from the spirit and scope thereof.

lclaim:

1. A hot water system comprising a housing having wall means defining a liquid reservoir adapted to contain a predetermined volume of water to be heated, means defining an open passage extending vertically through said housing, a plurality of tubes extending across said passage and providing liquid communication therethrough to the reservoir, and a heater positioned below said passage so that essentially all heat emanating from said heater travels up said passage, said tubes being arranged in said passage in successive pairs, the tubes of a pair being angularly disposed to each other at a predetermined angle selected as a function of the spiral of heat rising in said passage from said heater, the lowermost tube of a pair being disposed essentially from the uppermost tube of the next lower pair.

2. The system of claim 1 wherein said passage is cylindrical, said heater is a circular gas burner and the diameter of said burner is no greater than said passage.

3. The system of claim 1, wherein the heat emanating from said heater travels up said passage in a spiral path, the angle between the tubes of a pair being chosen to be the complement of the angle of spiral between the center lines of successive tubes.

4. The system of claim 1 wherein the number of tubes is at least equal to the circumference of said passage divided by twice the outside diameter of one of said tubes.

5. The system of claim 1 wherein the tubes are angularly disposed in said passage in horizontal planes to provide full coverage of the cross-sectional area of said passage as viewed along said passage.

6. A hot water system comprising a housing having wall means defining a liquid reservoir adapted to hold a predetermined volume of liquid, a filling opening defined in said housing, a fluid tight sealing means for closing said opening, means defining an open passage extending vertically through said housing, a plurality of tubes extending across said passage and providing communication therethrough to the reservoir, a hollow base member supporting said housing, a burner positioned below said passage within said base member so that essentially all heat emanating from said heater travels up said passage, a containerized source of fuel adapted to be carried by said housing and supply fuel to said burner, a containerized source of fluid pressure carried by said housing, a valve connected between said source of pressure and the interior of said housing and adapted to maintain a substantially constant fluid pressure on liquid in said reservoir, and a conduit leading from said housing adjacent the lower portion thereof.

7 The system of claim 8 wherein said burner is of the type emitting a circular flow of gas around the periphery thereof and comprises a gas housing having upper and lower imperforate wall means, a gas supply line extending substantially into said housing adapted to receive gas under pressure from said source, a tube extending between the exterior of said base member into said gas housing and being closed at the inner end thereof, said tube having a side opening therein positioned adjacent the end of said line so that gas emanating therefrom flows into said opening substantially tangentially, and a pair of substantially upwardly directed apertures defined in said tube at the periphery ot'said burner.

ii. The system oi'elaim l further including means for sensing when liquid in said housing reaches a predetermined temperature.

9. A hot water system comprising a housing having wall means defining a liquid reservoir adapted to hold a predetermined volume of liquid, a filling opening defined in said housing, a fluid tight sealing means for closing said opening, means defining an open passage extending vertically through said housing, a plurality of heat exchange means extending from the walls defining said passage and adapted to transfer heat intercepted thereby to liquid in said reservoir, a hollow base member supporting said housing, a burner positioned below said passage within said base member so that essentially all Oil heat emanating from said heater travels up said passage and the heat is intercepted by said heat exchange means, a containerized source of fuel adapted to be carried by said housing and supply fuel to said burner, a containerized source of fluid pressure carried by said housing, a valve connected between said source of pressure and the interior of saidhousing and adapted to maintain a substantially constant fluid pressure on liquid in said reservoir, and a conduit leading from said housing adjacent the lower portion thereof,

10. A hot water system comprising a housing having wall means defining a liquid reservoir adapted to hold a predetermined volume of liquid, a filling opening defined in said housing, a fluid tight sealing means for closing said opening, means defining an open passage extending vertically through said housing, a plurality of heat exchange means extending from the walls defining said passage and adapted to transfer heat intercepted thereby to liquid in said reservoir, a burner positioned below said passage so that essentially all heat emanating from said heater travels up said passage and the heat is intercepted by said heat exchange means, a containerized source of fuel adapted to be carried by said housing and supply fuel to said burner, a containerized source of fluid pressure carried by said housing, a valve connected between said source of pressure and the interior of said housing and adapted to maintain a substantially constant fluid pressure on liquid in said reservoir, and a conduit leading from said housing adjacent the lower portion thereof.

2 3 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,538,892 Dated November 10, 1970 Invefitofla) Richard H. Salews It is certified that error appears in the above-identified patent: and that said Letters Patent are hereby corrected as shown below:

Column 1, line 11, "predetmined" should read "predeterminedcolumn 7, claim 7, line 1, "claim 8 should read --claim 6--.

SIGNED AND SEALED FEB 2M (SEAL) Am mm! E. saHun-m, JR Commissioner of Patent! EdmdMFlemher, Ir.

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