GB2275998A

GB2275998A - Radiant heat retainer

Info

Publication number: GB2275998A
Application number: GB9319677A
Authority: GB
Inventors: Brian Paul Foster; Richard Keates
Original assignee: Hamworthy Heating Ltd
Current assignee: Hamworthy Heating Ltd
Priority date: 1993-03-12
Filing date: 1993-09-23
Publication date: 1994-09-14
Anticipated expiration: 2013-09-23
Also published as: GB9319677D0; GB9305134D0; GB2275998B

Abstract

A device for retaining radiant heat from burners 10 comprises a plurality of elongate Z-or S-shaped baffles 4. The baffles 4 may be shiny or dark in colour. The device can be used to reflect radiant heat back into a combustion chamber and to pre-heat secondary combustion air as the air passes through the device to enter the combustion chamber. <IMAGE>

Description

RADIANT HEAT REFLECTOR This invention relates to a radiant heat reflector for use in a location where radiant heat waves cause a direct loss of heat into an ambient environment.

Particularly, but not exclusively, the invention relates to a radiant heat reflector suitable for use with an atmospheric gas burner assembly.

Conventionally, it is known to provide a protective mat below the boiler of an atmospheric gas burner or the like, so as to protect the floor. However, with such an arrangement heat is lost because the mat simply absorbs the radiant heat.

The present invention sets out to provide a means for substantially reducing the loss of heat in this and other applications.

According to the present invention there is provided a reflector for reflecting radiant heat which comprises a plurality of baffles.

Preferably, the baffles are arranged also to pre-heat combustion air moving towards the source of the radiant heat.

In a preferred embodiment, the baffles are elongate and aligned in parallel and each has a generally zig-zagged cross-section, so as to be suitable for presenting a series of inclined faces and labyrinthine flow paths to radient heat.

The baffles can each be connected to and extend between a pair of common side plates. The baffles and side plates can be arranged in such a manner that only a portion of the cross-section of each baffle is attached to the side plates, with the remainder of the cross-section of the side plates depending or projecting outwardly from the assembly.

The baffles can, alternatively, be formed with a cross-section which is generally more "rounded", so that the cross-section of each baffle defines one or more "S"-shapes.

The baffles can be a dark colour, to improve the absorption of radiant heat, or can be provided with shiny surfaces in order to improve the reflection of radiant heat.

An embodiment of the invention, therefore enables the efficiency of, for example, a boiler to be improved in two ways: (i) by re-radiating heat back into the combustion chamber which is normally lost through the base of the boiler; (ii) by pre-heating combustion secondary air by virtue of conduction as the air has to pass through the device to enter the combustion chamber.

According to a second aspect of the invention there is provided a gas burner assembly with a radiant heat reflector assembly situated beneath at least one burner, the reflector being adapted to reflect heat radiated from the burner back towards the burner and also to allow secondary combustion air to pass therethrough towards the burner.

The radiant heat reflector provided in the assembly of the second aspect of the invention may be particularly configured to pre-heat the combustion air as it flows therethrough. Preferably, the radiant heat reflector will accord with the above described first aspect of the invention.

Embodiments of the invention will now be described, by way of example, and with reference to the accompanying drawings, in which Figure 1 is a partially cut-away side elevation of first embodiment of a radiant heat reflector according to a first aspect of the invention; Figure 2 is a plan view of the radiant heat reflector shown in Figure 1; Figure 3 is a schematic illustration of an atmospheric gas burner assembly incorporating a radiant heat reflector in accordance with the second aspect of the invention; and Figure 4 is a partial view of second embodiment of a radiant heat reflector according to the first aspect of the invention.

The reflector shown in Figure 1 comprises a pair of mutually spaced side panels 2 separated by an interposing series of baffle elements 4. Each side panel 2 is elongate and generally "C"-shaped in cross-section. Each baffle element 4 is elongate and extends between the two side panels 2 and is somewhat "Z"-shaped or zig-zagged in cross-section.

At each end, each baffle element 4 is connected to an adjacent one of the side panels 2 by means of a pair of lugs 6a, 6b. Each one of each pair of lugs 6a, 6b is inserted into a respective slot 8a, 8b provided in the adjacent side panel 2. During assembly, the lugs 6a, 6b, are caused to project through the slots 8a, 8b, and are subsequently bent over through about 90., so as to secure them in place and prevent their extraction from the slots.

Each pair of lugs is provided on a pair of end edges situated at a respective end of a respective baffle member and are directed 90 apart when folded over.

This provides a secure fixing, which cannot normally be released by simply levering the baffle element with respect to the side wall.

The baffles and side panels are preferably formed with a highly thermally reflective surface and are made from a material which will not degrade with repeated subjection to high temperatures. Metal is an ideal material for these purposes.

Figure 3 is a schematic view, which shows a heat reflector of the type described above situated for use in an atmospheric gas burner assembly.

In the arrangement shown, two burners 10 are provided for generating heat. Some of the heat radiated from the burners (A) is directed downwardly. The downwardly-radiated heat moves between the baffles 4 of the reflector. The baffles deflect the heat by virtue of the zig-zagged shape of the cross-section of the baffles, which presents a series of inclined surfaces to the incident radiation. The angle of the baffles and the pitch of the baffles cause most of the radiant heat to be reflected as shown by the broken lines (B).

Some of the radiated heat (C) will travel through the reflector, but in doing so will bounce off the baffles several times, thereby imparting heat to the structure of the baffles. As all secondary combustion air (D) has to pass through the reflector to pass into the combustion chamber, heat is picked up from the baffle assembly and therefore pre-heats the combustion air, which increases efficiency.

It has been found that, by utilising an arrangement such as shown in Figure 3, heat to water efficiency can be increased by up to 1%.

The reflector assembly could be modified by varying the cross-section of the baffle elements 4. For example, the cross-section of each baffle element can be curved to give a somewhat "S"-shape. This cross-section for the baffle elements is shown in Figure 4.

By increasing the number of baffle elements per unit length of the side panels 2, the effectiveness of the device can be increased.

The qualities of the surfaces of the baffle elements 4 will define the properties of the reflector as a whole.

For instance, a dark colour will increase absorption of radiant heat, whilst providing a shiny surface on the baffle elements will increase radiant reflectiveness.

Many further modifications and variations will suggest themselves to those versed in the art upon making reference to the foregoing, which is given by way of example only, and which is not intended to limit the scope of the invention.

Claims

1. A reflector for reflecting radient heat, comprising a plurality of baffles.

2. A reflector according to Claim 1 in which the baffles are arranged with space therebetween, so as to enable them to pre-heat combustion air moving towards a source of radient heat.

3. A reflector according to Claim 1 or 2, wherein the baffles are elongate and aligned in parallel.

4. A reflector according to any preceding claim, wherein at least some of the baffles are generally zig-zagged in cross-section, so that the baffles together present a series of inclined faces and labyrinthine flow paths to radient heat.

5. A reflector according to any preceding claim, wherein at least some of the baffles are generally 'St-shaped in cross-section, so that the baffles together present a series of inclined faces and labyrinthine flow paths to radient heat.

6. A reflector according to Claim 3 or any claim dependent on Claim 3 comprising a pair of side plates, each baffle being attached to a respective part of each side plate at respective end portions of the baffle.

7. A reflector according to Claim 6, wherein each baffle is connected to the side plates over only a portion of its cross-section, the remainder of the cross-section of each baffle depending or projecting outwardly from the assembly.

8. A reflector according to any preceding claim, wherein at least some of the baffles are provided with a surface which is dark in colour.

9. A reflector substantially as herein described with reference to Figures 1 to 3 of the accompanying drawings.

9. A reflector according to any preceding claim, wherein at least some of the baffles are provided with a shiny surface.

10. A reflector substantially as herein described with reference to Figures 1 to 3 of the accompanying drawings.

Amendments to the claims have been filed as follows 1. A reflector for reflecting radient heat, comprising a plurality of baffles, wherein the baffles are arranged with space therebetween, the arrangement being such, that in use, the baffles can allow a throughput of combustion air towards a source of radient heat and pre-heat the said combustion air as it moves.

2. A reflector according to Claim 1, wherein the baffles are elongate and aligned in parallel.

3. A reflector according to any preceding claim, wherein at least some of the baffles are generally zig-zagged in cross-section, so that the baffles together present a series of inclined faces and labyrinthine flow paths to radient heat.

4. A reflector according to any preceding claim, wherein at least some of the baffles are generally S' -shaped in cross-section, so that the baffles together present a series of inclined faces and labyrinthine flow paths to radient heat.

5. A reflector according to Claim 2 or any claim dependent on Claim 2 comprising a pair of side plates, each baffle being attached to a respective part of each side plate at respective end portions of the baffle.

6. A reflector according to Claim 5, wherein each baffle is connected to the side plates over only a portion of its cross-section, the remainder of the cross-section of each baffle depending or projecting outwardly from the assembly.

7. A reflector according to any preceding claim, wherein at least some of the baffles are provided with a surface which is dark in colour.

8. A reflector according to any preceding claim, wherein at least some of the baffles are provided with a shiny surface.