GB2450074A

GB2450074A - Support for a Gel Burner

Info

Publication number: GB2450074A
Application number: GB0704219A
Authority: GB
Inventors: Ian Joseph
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-03-05
Filing date: 2007-03-05
Publication date: 2008-12-17
Anticipated expiration: 2027-03-05
Also published as: GB0704219D0; GB2450074B

Abstract

A support for a heat-generating element, e.g. a gel burner, has a main body, at least one first support element extending from the body in a first direction, and at least one second support element extending from the body in a second direction. The first support element allows the support to rest on a surface so that the main body is spaced apart from the surface, and the second support element allows the heat generating element to rest in a spaced apart arrangement from the main body. The first and second elements are made from materials which have different thermal conductivity values, of which the second material has the higher value. The first support element may be fixed to the main body by screw threads, and the second support element may be fixed to the main body by welding. The support improves cooling of the heat-generating element, and the main body may include one or more holes which aid convection.

Description

Patent application Title: Improved Alcohol Burner Unit

Background

Alcohol based gel fire is increasingly becoming a popular product for those who want Instant heat without all the bother of flues and ventilations. Central heating means that many households Just want looks rather than hear from their fire. Small gel fires which can be positioned in virtually any situation provide just that. Alcohol gel is not new on the market -designs, such as small bowls or dishes, have been on the market since the late 1970's but modern designs, primarily from the U and Canada, had not had widespread popularity in the United Kingdom until around 2002 when primarily garden centres began to stock them.

DesIgns are normally simple "boxes" that hold a gel bowl, others include ceramic logs or pebbles. What most people just call alcohol, ethanol is the alcohol with which most people are most familiar. It is a renewable fuel produced from plants, It bums because plants absorb carbon dioxide during growth, "recycling" the carbon released during fuel combustion. It is therefore non-toxic, water soluble and quickly biodegradable.

Ethanol has a high calorific value compared to other sohd and liquid fuels (see Appendix for a comparison of the values of popular heating types). As a result, the actual energy and heat produced means that formally burners and the reservoirs holding the fuel were small to limit the build up of heat Consequently, a gel reservoir when filled could last for only about an hour.

The use of better, more appropriate materials for the construction of the burner and a design that improves convectIon cooling allows this invention safely to use a large reservoir that can bum hotter for longer. In addition, the design of this new burner means that it does not have to be kept in a purpose made bowl or dish but instead it can be placed and made safe In virtually any suitable space.

Introduction to drawings

Figure 1 is a perspective view of a support embodying the present Invention; FIgure 2 shows plan and elevation views of the support of figure 1; Figure 3 shows the support of figure 1 In combination with a heat-generating element; and Figure 4 shows plan and elevation views of the heat generating element shown in figure 3.

I

The real flame in this invention is preferably produced by an ethanol, isopropyl alcohol based gel that burns in a specially designed pot or reservoir. A match or other flame is used to ignite the gel's alcohol vapour that at Its hottest produces somewhere In the region of 2 kW of heat. The burner uses natural air convection to prevent a dangerous build up of heat, even after prolonged use. The burner assembly that achieves this comprises of separate parts that fit together as a single unit.

1. The burner assembly.

The burner plays a key part in how overheating is prevented and comprises of four separate parts, two of which, a convection ring and gel reservoir, have a direct role in how the cooling takes place. Limiting the direct contact between the burner assembly and its housing is key to controlling the build up of heat. This cooling Is achieved through building a two-level recess into the housing into which Is inserted a newly designed part that limits contact between the reservoir and the burner housing (see Figure 1). LimitIng contact and assisting airflow around the reservoir dissipates any heat created in the reservoir more quickly. The reservoir and device for limiting contact with the burner housing are made at least partially from metals with a low specific heat capacity that cools quickly.

A main body of the device comprises a substantially planar ring having convection holes formed therethrough to allow air to flow through the ring, thus aiding In heat dissipation It is metal pins manufactured into the device that limits direct contact between the reselvoir and the burner housing and creates an all-important dearance space for airflow.

The lengths of the lower pins are carefully calculated and are made from metals with a high specific heat capacity and low thermal conductivity. The lower pins are preferably screwed into the main body by means of co-operating screw threads formed on the pins and on inner surfaces of recesses or bones fonned In the main body, or may be Joined to the main body by any other similar type of engagement mechanism. ThIs Is advantageous since a welded or soldered joint may fall as a result of the high temperatures that will be experienced at these points. The arrangements of the pins on the ring are different on both sides. On the lower side the pins fit the diameter of the recessed hole in the burner housing.

from a material with a relatively low specific heat capacity and high thermal conductivity, such as aluminium, to remove thermal energy from the reservoir and transmit the energy swiftly to the main body. This design can be seen in Figure 2.

The reservoir's dimensions and material it is made from are central to the rate at which it cools, and especially important is the relationship between its diameter and total surface area. The diameter dictates the gel's surface area, the size of flame and heat produced.

The reservoir's total surface area directly affects contact with air and the rate at which it cools. The reservoir has one further important design feature. The manufacturing process used and its shape means that the reservoir is without Joints or seams, which may become weak over time and create a safety hazard. The reservoir's size corresponds to the cooling capacity of the other components of the burner.

A ring that can be placed into a collar in the reservoir acts to decreases or increases the size of the flame. The reservoir's design and position of the collar are found In FIgure 4 The remaining two parts of the burner assembly are the lid and a removable ring (not shown) that reduces or Increases the size of the flame. The lid's purpose Is to cut off air from reaching the surface of the burning gel and extinguish the flame. The burner housing is recessed so that the lid completely covers the gel reservoir. The flame reduction ring reduced how much burning gel is exposed and therefore decreases the flame's size and amount of heat generated. The ring's size corresponds to the cooling capacity of the other components of the burner and chimney. The reduction ring is removable and fits into a collar in the reservoir.

Appendix A Calorific values of s&ected popular household 1a&s Solid and Ikiuidfiiefs Gmgs* calodfic value/NJ kg 1 Ethanol 30 General purpose coal (5-10% water) 32-42 Peat (20% water) 16 Keroslne 47 Medium fuel oil 43 Wood (15% water) 16 North sea gas natural * 39 *Gross signifies that the water formed and liberated during combustion is in the liquid phase.

Source: Kaye and Laby table of physical constants.

Claims

claims 1. A support for a heat-generating element, comprising: a main

body; at least one first support element extending from the body in a first direction, the at least one first support element allowing the support to rest on a surface so that the main body Is spaced apart from the surface; and at least one second support element extending from the body In a second direction, the at least one second support element being adapted to allow a heat-generating element to rest thereon so that the heat-generating element is spaced apart from the main body, wherein the at least one first support element Is at least partially formed from a material having a first, lower thermal conductMty and the least one second support element Is at least partially formed from a material having a second, higher thermal conductivity.
2. A support according to ClaIm 1, whereIn the at least one first support element Is fixed to the main body by means of co-operating saew threads.
3. A support according to Claim 1 or 2, wherein the at least one first support element comprises a plurality of elongate first pins.
4. A support according to any preceding claim, wherein the second direction Is substantially opposite to the first direction.
5. A support according to any preceding claim, wherein the at least one second support element Is fixed to the main body by welding.
6. A support according to any preceding daim, wherein the at least one second support element comprises a plurality of elongate second pins.
7. A support according to any preceding daim, wherein the main body Is formed in a substantially ring-like shape having an Inner circumference and an outer circumference.
8. A support according to Claim 7, wherein the at least one first support element Is attached to the main body nearer the outer circumference and the at least one second support element is attached to the main body nearer the inner circumference.
9. A support according to Claim 7 or 8, wherein the main body is substantially planar, and the first and second directions are opposite and each substantially perpendicular to the plane of the main body.
10. A support according to any preceding daim, wherein the main body has one or more convection holes formed therein.
11. A support according to any preceding claim, wherein the main body is at least partially formed from a material having a thermal conductivity which is higher thermal conductMty than the first thermal conductivity.
12. A support according to ClaIm 11, wherein the main body is at least partially formed from the same material as the at least one second support element.
13. A support according to any preceding claim in combination with a heat-generating element in the form of a container for a combustible material, wherein the support may rest on a surface having an aperture therethrough and support the heat-generating element so that at least a part of the heat generating element passes through the aperture.
14. A support substantially as hereinbefore described, with reference to the accompanying drawings.
15. Any novel feature or combination of features disclosed herein.