IES20040806A2 - Indoor heater - Google Patents

Abstract

A gas powered indoor heater is provided. The heater includes a multi-part coal bed that provides for an efficient burning of the gas. The parts are dimensioned to fit together to ensure that they do not come apart during movement of the heater. <Figure 1>

Description

The present invention relates to indoor heaters and more particularly to 5 gas powered indoor heaters. The invention particularly relates to portable indoor heaters which may be provided with their own gas supply and are dimensioned to appear as a pot belly stove.

Background Of The Invention Indoor gas heaters are well known. They vary from those heaters that are powered off a mains or central gas supply such as a gas space heaters which operate like a central heating system or coal effect gas heaters which fit into a traditional fireplace and are becoming more and more common as replacements for the real coal fire.

In the portable variety of has heaters a brand of heater such as the SuperSer™ brand of heaters that are portable heaters utilising a Calor™ brand of gas bottle. The gas from the bottle is fed to a grill type effect where it is distributed across a grid where it is ignited and generates heat. Although these are particularly effective in heating small areas, they are aesthetically not very pleasing and there is a desire to provide alternative types of portable gas heaters. One example of a recent addition to the gas powered portable heater is the pot boiler type of flueless heater which incorporates a coal or log effect arrangement to give the appearance of a traditional type fire or stove. The stove is mounted on four legs, and they are typically provided with a set of wheels at the rear legs to enable them to be tipped and moved around the room to a desired location.

These types of heaters operate by passing the gas from a storage unit, typically butane, to a gas burner box, which is located under the coals. The £04 08 Οβ burner box provides a mixing of air and gas to form a combustible combination which, when lit, is distributed over the coals above. As it is necessary to ensure that an even distribution is provided, and therefore that the coal bed is not disturbed when the stove is moved, the coal bed is provided in a single moulded unit. The shapes and configurations of the coals in this single moulded unit are known to be different in appearance but due to the requirement to maintain a stable unit in the portable arena, have always been provided as single integer.

The present invention is directed towards these types of heaters and provides an improved portable gas stove that generates more heat than that heretofore provided.

Summary Of The Invention Accordingly, a first embodiment of the invention provides a portable flueless gas heater dimensioned to receive a bottle gas supply, the heater having a fluid conduit that may be coupled to a received bottle gas supply, the fluid conduit providing a gas supply to a burner unit located in a lower region of the heater, the burner unit adapted to effect a mixing of the gas with air to provide a combustible mixture which, on ignition provides a flame which is distributed over a coal bed located above so as to heat the coals, and wherein the coal bed is provided of a multi-part construction, a first part forming a base portion of the coal bed and being dimensioned to receive one or more distinct parts, the one or more distinct parts forming upper portions of the coal bed, the upper portions being co-operable with the base portion to provide, in use, an integrated coal bed over which the flame is distributed.

By providing a multi-part construction, the coal bed of the present invention has a greater surface area than heretofore provided in portable gas heaters. As there is proportionality between the surface area of the coal bed and the amount of heat that is transferred from the flame to the coal bed, it is desirable to increase the surface area. £04 08 06 The cooperation between the base portion and the one or more upper portions is desirably achieved by an inter-engagement of the parts. This is desirably achieved by providing seats or valleys in an upper surface of the lower portion within which the upper portions are seatable. The seating of the upper portions within the lower portion provides a secure inter-engagement with minimises the possibility of the individual parts of the multi-parts becoming separated during movement of the heater.

The lower portion is desirably of larger dimensions than the individual upper portions. Desirably three upper portions are provided, two of substantially the same dimensions adapted to be located at either end of the lower portion thereby providing outer portions, and a third portion of larger dimension than the outer portions providing a mid-portion.

The coal bed is desirably seated so as to be angularly orientated towards the front of the heater. This angular orientation serves to ensure that if the heater is tipped rearwardly, as will happen during the movement of the heater, that the angle of the coal bed will change in orientation till it is approximately parallel with the ground. As it is normal for the tipping of the heater to be of the order of about 15-30 degrees, such angular orientation of the coal bed is desirably effected. This is typically achieved by providing a coal bed receiving portion within the heater, the receiving portion being adapted to receive and support a coal bed thereon, the receiving portion being provided at an angle of about 15-30 degrees relative to the ground on which the heater is located.

In use, the heat generated by the interaction between the coal bed and the flame desirably is radiated outwardly from the coal bed. In addition convective air currents pass upwardly from the coal bed where they pass through an outlet provided in an upper region of the heater. In certain embodiments a catalytic converter CAT may be provided before the convective air currents pass out of ¢040806 the heater, the CAT adapted to ensure that the exhaust gases do not include levels of dangerous gases beyond what is permissible.

The burner unit typically includes a oxygen depletion sensor (ODS) which is configured to effect an extinguishing of the flame on detection of impermissible levels of defined gases in the environment where the heater is being used. The ODS is typically configured to sense for high levels of carbon dioxide and to effect a shut down of the unit when high levels are detected.

The ignition of the burner unit is desirably effected by a piezo-electric mechanism.

The burner unit also includes a pilot light which may be provided as part of the ODS system.

These and other features of the present invention will be better understood with reference to the following drawings.

Brief Description Of The Drawings Figure 1 is a perspective view from the front of a portable gas heater according to the present invention.

Figure 2 is a cross section through the heater of Figure 1 showing the air flow.

Figure 3 is a detail of a coal bed in accordance with the invention.

Figure 4 is an exploded detail of the coal bed of Figure 3.

Detailed Description Of The Drawings The present invention will now be described with reference to the following figures. £040806 Figure 1 shows a perspective view of a portable heater 100 in accordance with the present invention, and Figure 2 shows a cross section through this heater. In this embodiment, the heater 100 is a portable flueless gas heater dimensioned to receive a bottle gas supply and dimensioned to be similar to a traditional potbelly stove. The heater 100 includes a door 105 provided in a front portion 110 of the heater, the door including a glass window pane 115 (of a heat resistant variety). The door 105 is hinged so as to enable it to be opened to give access to an interior portion 120 of the heater. Provided within the interior portion of the heater is a coal bed 125, which when the heater is lit will give a coal fire effect visible through the glass window. The heater incorporates a number of aesthetic features such as an ash plate 130 provided in a lower region 150 of the heater but also functional features such a grills 135, 140 provided in an upper region 145 of the heater and configured to let air pass from the interior portion 120 of the heater upwardly and outwardly from the heater. The heater stands on a plurality, desirably four, legs 155 but only the front two legs are visible in the view of Figure 1.

As seen in the cross section of Figure 2, the heater 100 includes a fluid conduit 200 that may be coupled to a received bottle gas supply (not shown but of the type known to the person skilled in the art such as those provided by Calor™. The fluid conduit 200 provides a gas supply to a burner unit 205 located in the lower region 150 of the heater 100. The burner unit is of a conventional manufacture and is adapted to effect a mixing of the gas with air to provide a combustible mixture which, on ignition provides a flame which is distributed over the coal bed 125 located above. This distribution or interaction between the flame and the coal bed serves to heat the coals. The artificial coals are manufactured from a chopped ceramic fibre that is moulded to shape and coated black. The manufacture of such coals will be well known to those skilled in the art. ¢040806 In use, the heat generated by the interaction between the coal bed and the flame desirably is radiated outwardly from the coal bed and passes through the window 115. In addition, convective air currents 210 pass upwardly from the coal bed where they pass through the grill outlet 135 provided in the upper region 145 of the heater. In certain embodiments such as this shown in Figure 2, a catalytic converter (CAT) 220 may be provided to ensure that before the convective air currents pass out of the heater, that the exhaust gases do not include levels of dangerous gases beyond what is permissible by safety standards.

Additional air currents 215 may pass up the back of the heater where they are heated by contact with a metal plate 225 at the back of the coal bed and pass upwardly and outwardly through the second set of vents 140.

The burner unit 205 typically includes a oxygen depletion sensor (ODS) which is configured to effect an extinguishing of the flame on detection of impermissible levels of defined gases in the environment where the heater is being used. The ODS is typically configured to sense for high levels of carbon dioxide and to effect a shut down of the unit when high levels are detected. The ODS is internal to the burner unit and is of a known construction. Similarly, the burner unit incorporates a pilot light and ignition is effected using a piezoelectric mechanism.

As shown in Figures 3 and 4, the coal bed 125 is provided of a multi-part construction. Such a construction includes a first part 300 forming a base portion of the coal bed and being dimensioned to receive one or more distinct parts 310, the one or more distinct parts forming upper portions of the coal bed The upper portions are co-operable with the base portion to provide, in use, an integrated coal bed over which the flame is distributed. £040806 By providing a multi-part construction, the coal bed of the present invention has a greater surface area than heretofore provided in portable gas heaters. As there is proportionality between the surface area of the coal bed and the amount of heat that is transferred from the flame to the coal bed, it is desirable to increase the surface area. Such an increment in surface area is provided as the individual distinct parts 310 form three dimensional configurations which have outer surfaces with which the flame can interact. This differs from the traditional single piece moulded coal bed where upper “coals” had no lower surfaces thereto so in effect all that was achieved was not a stacking of coals but rather a raising of the overall height of the coal bed.

The burner box 205 is suitably dimensioned to extend substantially the length of the coal bed above and serves to mix the gas from the storage bottle with air, which when ignited will form a flame. The flame is the distributed over the entire length of the coal bed. The matrix arrangement of the multi-part construction of coal bed forms an efficient path for the flames to travel through the coal bed imparting heat to the individual coals. This heat is then radiated outwardly from the heater. At the same time hot air that passes through the coal bed and upwardly through a grate provided at the top of the stove. This convection current also serves to heat the environment. The heat generated is purely from combusted air and converted in to convected and radiated heat.

The multilayer coals increase the radiated effect over single layer.

The lower portion 300 is desirably of larger dimensions than the individual upper portions 310. Desirably three upper portions 315, 320, 325 are provided, two 315, 325 of substantially the same dimensions as each other and adapted to be located at either end of the lower portion thereby providing outer portions, and a third portion of larger dimension 320 than the outer portions providing a mid-portion.

IE04 08 06 The cooperation between the base portion and the one or more upper portions is desirably achieved by an inter-engagement of the parts. This is desirably achieved by providing seats or valleys 400 in an upper surface 405 of the lower portion within which the upper portions are seatable. The valleys are desirably provided along both the major 410 and minor axis 415 of the lower portion so as to provide a criss-cross arrangement on the upper surface of the lower portions. The individual upper portions 315, 320, 325 are received within the valleys 400. The seating of the upper portions within the lower portion provides a secure inter-engagement with minimises the possibility of the individual parts of the multi-parts becoming separated during movement of the heater.

As shown in Figure 2, the coal bed is desirably seated so as to be angularly orientated towards the front of the heater. This angular orientation preferably at an angle Θ of the order of 10-30 degrees serves to ensure that if the heater is tipped rearwardly, as will happen during the movement of the heater, that the angle of the coal bed will change in orientation till it is approximately parallel with the ground. As it is normal for the tipping of the heater to be of the order of about 15 degrees, such angular orientation of the coal bed is desirably effected. This is typically achieved by providing a coal bed receiving portion 230 within the heater, the receiving portion being adapted to receive and support a coal bed thereon, the receiving portion being provided at an angle of about 15-30 degrees relative to the ground on which the heater is located.

It will be understood that the present invention provides a flueless gas fuelled heater for use in an indoor environment. Arising from strict regulations on the permissible levels of carbon monoxide (CO) output from the heater, traditionally units have incorporated CATS to ensure clean burning. CE regulations specify that the unit burns the gas cleanly with or without the CAT and heaters are required to pass certain tests before they are allowed on the ΙΕΟ 4 08 Οβ market. In addition the ODS (oxygen depletion sensor), that must be fitted, will cut the unit out upon reaching a certain build up of CO2 in the room (therefore a deduction of 02 as these two are related). Because the unit has to burn the gas correctly the rate of production of CO in the exhaust is low and by the time the required amount of CO2 is produced (therefore cutting the heater out) the CO concentration in the room is within safe limits. This has to be the case without a CAT for approval purpose. Because the CAT reduces further the amount of CO being exhausted by converting it into CO2 (the rate of CO2 production against CO production is higher with a CAT) then it is possible to state a smaller and obviously more practical room size for the same heater. The important aspect to remember is that for non-flued heaters the limits, under the standard, for CO and CO2 production are a lot stricter than for flued heaters. The burn quality within the heater is related to the passage of the flame through the coal bed and it is important that this is properly arranged, as changes in the coal arrangement can have an incredible effect on the combustion. Heretofore it was not possible to ensure that the designed arrangement was constant during the life of the heater, and this is why a mobile heaters have a one piece ceramic coal matrix. The mating arrangement provided by the present invention enables a multi-part coal bed construction to be used in a mobile gas fuelled heater, which will maintain the set configuration of the multi-parts relative to one another during transport and use of the heater. This therefore ensures that a better flame path through the coal bed can be provided- larger surface area of coals with which the flame can be in contact- while at the same time ensuring that the coal bed will not come apart resulting in higher emissions than are safe and allowable.

The present invention has been described with reference to a preferred embodiment and will be understood that medications may be made without departing from the scope of the invention. The words upper, lower, inner and outer have been used for ease of explanation and again it is not intended to limit the invention in any way by the use of these positional adjectives. Similarly, the words comprises/comprising when used in this specification are to specify ¢040806 the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers , steps, components or groups thereof.

Claims (5)

Claims

1. A portable flueless gas heater dimensioned to receive a bottle gas supply, the heater having a fluid conduit that may be coupled to a received bottle gas supply, the fluid conduit providing a gas supply to a burner unit located in a lower region of the heater, the burner unit adapted to effect a mixing of the gas with air to provide a combustible mixture which, on ignition provides a flame which is distributed over a coal bed located above so as to heat the coals, and wherein the coal bed is provided of a multi-part construction, a first part forming a base portion of the coal bed and being dimensioned to receive one or more distinct parts, the one or more distinct parts forming upper portions of the coal bed, the upper portions being co-operable with the base portion to provide, in use, an integrated coal bed over which the flame is distributed.

2. The heater as claimed in claim 1 wherein the cooperation between the base portion and the one or more upper portions is achieved by an interengagement of the parts, the inter-engagement being achieved by providing seats or valleys in an upper surface of the lower portion within which the upper portions are seatable.

3. The heater as claimed in any preceding claim wherein the lower portion is of larger dimensions than the individual upper portions, three upper portions being provided, two of substantially the same dimensions and adapted to be located at either end of the lower portion thereby providing outer portions, and a third portion of larger dimension than the outer portions providing a mid-portion.

4. The heater as claimed in any preceding claim wherein the coal bed is seated so as to be angularly orientated towards the front of the heater. ΙΕΟ 4 OS Οβ

5. A heater substantially as hereinbefore described with reference to and or as described in any one of Figures 1 to 4.