Portable L. P. Gas Space Heater

Abstract

An attractive lightweight portable L. P. gas space heater comprises a boxlike rectangular housing having space for two disposable L. P. gas cartridges. A circular catalytic heating element is mounted on the front of the heater. The catalytic unit is a porous pad which allows the gas to seep through and upon contact with the air burns the same on its outside surface. Since no premixing with air is required the back space behind the catalytic pad in the heating element is directly connected to one of the two L. P. cartridges in the housing or the carrying case. To permit compact construction, a flexible gas line is used so that the L. P. cylinder can be connected thereto external of the housing. The gas line attaches to the cylinder with a finger adjustable regulator valve which valve, when mounted on the cartridge, is designed to have its control knob extend through the housing on the top portion so that it is readably accessible. The rear wall of the carrying case is hinged to open so that the gas cartridges, one of which is a spare, are accessible and can be readily exchanged.

Description

DESCRIPTION

There are many instances where a small portable radiant heater is useful such as for camping, hunting as in duck blinds, construction work, spectator sports such as football, in ice fishing shacks and in many such other applications. It is of course desirable that such a heater be simple to operate, safe adjustable and have a relatively long operating time.

The present invention meets these objectives. The propane heater of this invention employs a planer catalytic radiant heating pad that effects relatively slow catalytic combustion of the propane gas on the surface of the pad. It can be considered in a sense flameless and is quite easy to operate. The flow of gas need only be started through the pad and the lower portion of it heated slightly, as with a match, to start the catalytic reaction.

The overall design of the present heater is quire simple and attractive. The housing is designed to contain two standard disposable L. P. gas cartridges, one of which is connected to the backside of the catalytic heating element through a control valve-regulator and a flexible connecting line. The control knob of the regulator extends through the housing and is readily accessible to finger tip control.

The regulator valve is a subject matter of a copending application entitled "Pressure Regulator Valve for L. P. Cartridges" in the name of Irving H. Stenner, filed simultaneously herewith and assigned to a common assignee.

DRAWINGS

FIG. 1 is a perspective view of the heater from the front;

FIG. 2 is a top plan view of the heater;

FIG. 3 is a perspective view of the heater from the backside showing the access door partly open, and

FIG. 4 is a cross-sectional view of the means to attach the L. P. gasline to the catalytic unit.

DESCRIPTION

The heater comprises a carrying case 10 or housing that has an adjustable handle 11 attached to the sides of the housing. Tightening knobs 12 permit the handle to be placed in the position shown in FIG. 1 for carrying, or in the position shown in FIG. 3 to stabilize the heater when it is resting on a surface.

A circular heating element, generally indicated at 15, is affixed to the front of the carrying case by means of bracket 16. The heating element comprises an enclosed pan 17 that makes a gastight seal about and retains catalytic pad 19. The catalytic element or pad 19 is porous and comprises an aluminum silicate impregnated with a platinum catalyst, usually by spraying the catalytic solution thereon. A preferred catalytic pad is sold by Bruest Inc., Independence, Kansas. A guard 20 clips over the heating element 15 to prevent body contact therewith or the accidental contacting of flammable material.

The underside of the heating element 15, i.e., pan 17 is connected to the propane gas supply by a conduit 25 which is attached to pan 17 by nut 26 and extends through to the inside of housing 10. A collar 24 holds an orifice 27 at the outlet, which orifice helps to control the gas flow. Conduit 25 is attached to a flexible hose 28 which ends in a regulator valve 29 having a control knob 30. The length of flexible line 28 is sufficient to permit regulator 29 to be attached to the neck of a disposable L. P. gas cartridge by screwing the two together outside of the carrying case. The cartridge with the regulator attached is held within the cabinet by clip 31 with the control knob 30 of the regulator extending through the housing as shown in FIGS. 1 and 2. A reserve cartridge 33, shown in outline, is retained within the housing by clip 32.

The backwall 14 of the housing is hinged so that it can be opened to permit access to the L. P. gas cartridges and the regulator valve 29. This valve has an activation rod or plunger so that when it is connected to the cartridge it will open the valve therein and draw gas.

To operate the device, the gas cartridge is connected to regulator valve 29, the knob of the valve is inserted through hole 34 in the housing and the cartridge is clipped in place within retaining clip 31. A metal finger 18 engages the body of valve 29 to prevent rotation thereof. Knob 30 is then rotated to the on position. The type of valve shown has a control button 30a in the knob which when depressed overrides the regulator valve and holds it in the full open position so that it is possible to flood pan 17 with propane gas. After this flooding, a match or the like is held to the lower portion of the catalytic pad to initiate the catalytic combustion which then spreads upwardly and over the whole pad. The rate of gas consumption and heating is then adjusted to the desired level by rotation of control valve 30.

With the type of catalytic heating pad used, a temperature of about 235.degree. F. is necessary in order to initiate the catalytic combustion. This type of pad tends to absorb moisture in storage and it is for this reason that the override control button 30a was found to be necessary. This feature permits ready ignition of the heater even under quite adverse conditions.

Claims

I claim:

1. A portable L.P. gas radiant heater comprising:

a. a rectilinear housing having a carrying handle and a hole adapted to receive the control knob of a valve and adapted to detachably retain inside thereof two upright L. P. gas cartridges side-by-side;

b. a pressure-regulator and control valve means within said housing and adapted to be directly mounted to the neck of an L.P. gas cartridge and to draw gas therefrom, said control valve having a finger-adjustable control knob adapted to extend through the hole in said housing when mounted on an L.P. gas cartridge therein;

c. a generally planer radiant heating element having a guard thereover to prevent body contact therewith and mounted externally on said housing with the plane thereof being parallel to the plane defined by the longitudinal axis of said two L.P. gas cartridges, said heating element comprising a porous catalytic radiant heating pad and being adapted to pass gas therethrough without premixing with air; and

d. a flexible gasline connecting said control valve to said heating element, said gas line passing through and being mounted on said housing beneath said heating element and having a length and flexibility sufficient to permit removal of said control valve from said housing and the mounting of the same on one of said two L. P. gas cartridges:

e. the rear wall of said housing opposite from the wall mounting said heating element being detachably mounted to permit access to the interior of said housing.

2. The heater of claim 1 wherein said rear wall is hinged to said housing along one edge thereof.

3. The heater of claim 1 wherein said heating element is circular and comprises a platinum impregnated aluminum silicate, and wherein said guard makes a snap fit therewith.

4. The heater of claim 1 wherein said pressure-regulator control valve has associated therewith a manually operated control for positioning said valve at the full open position to permit flooding of said heating element with gas.

5. The heater of claim 1 wherein the hole in said housing has associated therewith means to prevent said control valve means from rotating.