GB2296317A

GB2296317A - Liquid fuel burner apparatus

Info

Publication number: GB2296317A
Application number: GB9425535A
Authority: GB
Inventors: Terry Hibbard
Original assignee: HARWORTH HEATING Ltd
Current assignee: HARWORTH HEATING Ltd
Priority date: 1994-12-19
Filing date: 1994-12-19
Publication date: 1996-06-26
Also published as: GB9425535D0

Abstract

Burner apparatus (20) comprising a burner housing (4), a burner head (6), a motor (8), a fuel pump (10) and a fan (12), the burner apparatus (20) being such that the fan (12) and the motor (8) form a single integral unit, and the fuel pump (10) is separately driven from the fan (12) and the motor (8). <IMAGE>

Description

BURNER APPARATUS This invention relates to burner apparatus.

The burner apparatus may be of especial use in domestic, small industrial and small commercial markets.

Burner apparatus for use in heating and/or cooking is well known. The burner apparatus may operate with a liquid fuel such as fuel oil and such burner apparatus operates satisfactorily when it is constructed for dealing with large oil flows. Where the burner apparatus is constructed for small oil flows, then overheating of parts of the burner apparatus become a problem.

It is an aim of the present invention to obviate or reduce the above mentioned problem.

Accordingly, in one non-limiting embodiment of the present invention there is provided burner apparatus comprising a burner housing, a burner head, a motor, a fuel pump and a fan, the burner apparatus being such that the fan and the motor form a single integral unit, and the fuel pump is separately driven from the fan and the motor.

The burner apparatus of the present invention is advantageous in that the motor is able to be cooled by the fan. Thus the fan and motor single integral unit is a single integral self-cooling unit. Furthermore, because the pump is separately driven from the fan and the motor, further heat build up via the fuel pump can be avoided.

The burner apparatus may be one in which the fuel pump is positioned outside the burner housing and in such a position that it is in an air stream of air drawn in by the fan during operation of the burner apparatus, whereby the fuel pump is air cooled.

The burner apparatus may include valve means positioned between the fuel pump and a downstream end of the burner head.

In one embodiment of the invention, the valve means is positioned in a fuel supply line between the fuel pump and the burner head. In this case, the valve means is advantageously positioned in the fuel supply line and in the path of the air stream drawn in by the fan, whereby the valve means is cooled by the air stream.

In another embodiment of the invention, the valve means is connected to an upstream end of the burner head.

The valve means is preferably a solenoid valve. Other types of valve means may however be employed.

The burner apparatus may include a pressure switch which is located in the burner housing and which controls operation of the fuel pump such that the fuel pump only operates when appropriate air pressure is detected by the pressure switch.

The fuel pump will usually be a fuel pump for pumping a liquid fuel. The liquid fuel will usually be fuel oil. The burner apparatus may operate on any suitable and appropriate type of fuel.

Usually, the burner head will include a jet through which the liquid fuel is pumped under pressure.

An embodiment of the invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 shows a first type of known burner apparatus; Figure 2 shows a second known type of burner apparatus; and Figure 3 shows burner apparatus in accordance with the present invention.

Referring to Figure 1, there is shown burner apparatus 2 which operates on relatively small fuel oil flows and which comprises a burner housing 4, a burner head 6, a motor 8, a fuel pump 10, and a fan 12. The burner apparatus 2 also comprises valve means in the form of a solenoid valve 14.

During operation of the burner apparatus 2, the fan 12 sucks in air as shown by arrows 16.

The burner apparatus shown in Figure 2 was generally known and used since approximately 1960. It will be noted that the motor 8, the fan 12, and the fuel pump 10 are all in line as shown in Figure 1. This is because the motor 8 drives both the fuel pump 10 and the fan 12. The burner apparatus 2 shown in Figure 1 suffers from overheating problems.

Referring now to Figure 2, there is shown burner apparatus 18 in which similar parts as in Figure 1 have been given the same reference numerals for ease of comparison and understanding. The burner apparatus 18 was generally known and available since approximately 1980. Most manufacturers have adopted the burner apparatus 18 and the burner apparatus 2 has largely been superceded by the burner apparatus 18. In the burner apparatus 18, it will be noted that the motor 8, fuel pump 10 and fan 12 are again in line as in the burner apparatus 2. In Figure 1, the order of components was the motor 8, the fan 12 and the fuel pump 10. In Figure 2, the order of components is the fuel pump 10, the motor 8 and the fan 12.

The burner apparatus 18 also has many problems due to heat build up. These problems are mainly caused by heat build up in the fuel pump 10. This is because the fuel pump 10 has a solenoid valve 14 attached to it and this solenoid valve 14 acts as a heat generator.

Also, the pump is gear driven and it naturally builds up heat through friction. Further heat is built up from the motor 8.

In the burner apparatus 18, the fuel pump 10 and/or the motor 8 get hot and a closed thermal loop sets up. This results in lubrication inefficiencies in bearings of the motor 8. Also, the increased temperature may allow a front oil seal in the fuel pump 10 to leak, thereby allowing the fuel oil which is usually paraffin to leak into the motor 8. This leaking of the fuel oil into the motor 8 then creates even more problems.

The above described problems occur on burner apparatus 2 which is capable of dealing with large fuel oil flows. The problems are however especially pronounced on burner apparatus where a very low throughput of fuel oil is required, for example a through-put of less than 0.5 USA gallons per hour. This is because the pressurised fuel oil is operating at such a low through-put in the burner apparatus 2 and 18 that it is unable to act as a coolant and is thus unable to reduce the problems due to overheating mentioned above.

Referring now to Figure 3, there is shown burner apparatus 20 in which similar parts as in Figures 1 and 2 have again been given the same reference numerals for ease of comparison and understanding. In Figure 3, it will be seen that the fan 12 and the motor 8 form a single integral unit. It will also be seen that the fuel pump 10 is separately driven from the fan 12 and the motor 8.

The fuel pump 10 is positioned outside the burner housing and in such a position that it is in an air stream of air drawn in by the fan 12 during operation of the burner apparatus 2. The air stream is indicated by the arrows 16. The fuel pump 10 is thus able to be air cooled.

The valve means in the form of a solenoid valve 14 is positioned between the fuel pump 10 and a downstream end 22 of the burner head 6. More specifically, the solenoid valve 14 is in a fuel supply line 24 extending between the fuel pump 10 and the burner head 6. As can be seen from Figure 3, the solenoid valve 14 is positioned in the fuel supply line 24 such that it is also in the path of the air stream which is denoted by the arrows 16 and which is drawn in by the fan 12. Thus the solenoid valve 14 is cooled by the air stream.

The burner apparatus 20 includes a pressure switch 26. The pressure switch 26 is located as shown in the burner housing 4 in the vicinity of the burner head 6. The pressure switch 26 controls operation of the fuel pump 10 and the pressure switch 26 is electrically wired by wiring (not shown) to the fuel pump 10 in order to afford this control over the fuel pump 10. The pressure switch 26 is thus able to ensure that the fuel pump 10 only operates when appropriate air pressure in the vicinity of the burner head 6 is detected by the pressure switch 26.

The fuel pump 10 is mounted on a mounting bracket 28. The burner head 6 includes a jet 30 through which the liquid fuel is pumped under pressure by the fuel pump 10. The fuel pump 10 is self driven. The fuel pump 10 has a piston (not shown) in it. This piston is made to reciprocate via the effect of electrical current supplied through a wound copper coil (not shown). Thus the fuel pump 10 is a solenoid-type reciprocating pump 10. The return stroke of the piston in the fuel pump 10 is effected via a spring (not shown).

The burner apparatus of the present invention is advantageous in that the closed loop effect of fuel pump 10 and motor 18 in the known burner apparatus is removed. Also, in the burner apparatus 20, the single unit of the motor 18 and the fan 12 is self cooling because the motor is actually the centre of the fan.

The burner apparatus 20 is further advantageous in that the fuel pump 10 is separated from the solenoid valve 14, thus reducing the heat build up effect. The fuel pump 10 is additionally air cooled as it is positioned directly in the air path drawn into the fan 12. The solenoid valve 14 is also air cooled because it is again positioned directly in the air stream drawn into the fan 12.

The burner apparatus 20 is still further advantageous in that it is extremely compact. This is advantageous in enabling the burner apparatus easily to be installed, especially in locations where space is restricted. The fan 12 is able to cool the motor 8, the fuel pump 10 and the solenoid valve 12, all in a compact unit. The cooling ensures that the burner head 6 can operate almost at ambient temperatures and does not suffer from heat build up and associated problems.

It is to be appreciated that the embodiments of the invention described above with reference to the accompanying drawings have been given by way of example only and that modifications may be effected. Thus, for example, the burner apparatus 20 shown in Figure 3 uses small oil flows and the burner apparatus 20 thus is especially useful for the domestic market, the small industrial market and the small commercial market.

However, the burner apparatus 20 may be produced to deal with larger oil flow through-puts and it may be sold in other markets. If desired, the solenoid valve 14 can be placed at an upstream end 32 of the burner head 6. The burner apparatus 20 can be produced to be wall mounted or floor standing. The burner apparatus 2 can be used for providing central heating and/or hot water in homes, offices and other environments. The burner apparatus 2 can generally be used in any situation where known burner apparatus is currently being used, including providing cooking facilities, for example via hotplates.

Claims

1. Burner apparatus comprising a burner housing, a burner head, a motor, a fuel pump and a fan, the burner apparatus being such that the fan and the motor form a single integral unit, and the fuel pump is separately driven from the fan and the motor.

2. Burner apparatus according to claim 1 in which the fuel pump is positioned outside the burner housing and in such a position that it is in an air stream of air drawn in by the fan during operation of the burner apparatus, whereby the fuel pump is air cooled.

3. Burner apparatus according to claim 1 or claim 2 in which the valve means is positioned between the fuel pump and a downstream end of the burner head.

4. Burner apparatus according to claim 3 in which the valve means is positioned in a fuel supply line between the fuel pump and the burner head.

5. Burner apparatus according to claim 4 in which the valve means is positioned in the fuel supply line and in the path of the air stream drawn in by the fan, whereby the valve means is cooled by the air stream.

6. Burner apparatus according to claim 3 in which the valve means is connected to an upstream end of the burner head.

7. Burner apparatus according to any one of claims 3 6 in which the valve means is a solenoid valve.

8. Burner apparatus according to any one of the preceding claims and including a pressure switch which is located in the burner housing and which controls operation of the fuel pump such that the fuel pump only operates when appropriate air pressure is detected by the pressure switch.

9. Burner apparatus according to any one of the preceding claims in which the burner head includes a jet through which a liquid fuel is pumped under pressure.

10. Burner apparatus substantially as herein described with reference to Figure 3 of the accompanying drawings.