GB2243205A

GB2243205A - Boiler

Info

Publication number: GB2243205A
Application number: GB9106812A
Authority: GB
Inventors: Hedley Roland Mickleburgh
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-04-04
Filing date: 1991-04-02
Publication date: 1991-10-23
Anticipated expiration: 2011-04-02
Also published as: GB2243205B; GB9007621D0; GB9106812D0

Abstract

A boiler comprises a casing having an inner wall 10 defining a combustion chamber and an outer wall 11 coextensive therewith, with an enclosed water-flow chamber 9 between the walls, a water inlet and a water outlet for the water-flow chamber, a burner 4, 5 extending into the combustion chamber for introducing burning fuel thereinto, an outlet 3 around the burner for escape of the combustion products from the combustion chamber, and a duct 6 for passing the combustion products from the outlet 3 over the outer wall 11. <IMAGE>

Description

BOILER Field of the Invention This invention relates to a boiler, for example a domestic water-heating boiler for central heating and the like.

Domestic water-heating boilers, particularly oilfired boilers, are typically formed as a double-skinned tube of circular or rectangular cross-section, open at the top and bottom. The bottom end is closed off and the top is divided into two, one half for a flue off-take and the other half for an inspection/cleaning door. As a result of this, heat exchange takes place only through the sides of the tube. The present invention seeks to improve the efficiency of heat transfer.

Summary of the Invention Accordingly, the present invention provides a boiler comprising a casing having an inner wall defining a combustion chamber and an outer wall coextensive therewith, with an enclosed water-flow chamber between the walls, a water inlet and a water outlet for the water flow chamber, a burner extending into the combustion chamber for introducing burning fuel thereinto, and an outlet from the combustion chamber for escape of the combustion gases.

Preferably, there is a single opening through the casing into the combustion chamber, the burner extending through the opening and the combustion gases escaping through the opening around the burner. The burner and gas outlet are preferably coaxial. Means may be provided outside the combustion chamber for causing the escaping combustion gases to pass over a portion of the outer wall of the casing. In one embodiment, the gases are guided over two sides of the outer wall before discharge to a flue. The boiler is preferably a domestic water-heating oil-fired boiler.

The casing is suitably cuboid, with a water inlet at one end thereof and a water outlet at the opposite end thereof.

The boiler of the invention presents a much greater area for heat exchange for a given size of combustion chamber than a conventional boiler, thus permitting greater thermal efficiency to be achieved. The boiler thus can be made smaller than a conventional boiler. Manufacture is also simplified and both factors can lead to a reduction in manufacturing costs.

Brief Description of the Drawings Reference is made to the drawings, which illustrate schematically preferred embodiments of the invention, and in which: Figure 1 is a sectional elevation on line A-A in Figure 2 of a boiler according to one embodiment; Figure 2 is a sectional rear view on line B-B in Figure 1; Figure 3 is a view corresponding to that of Figure 1 showing an alternative embodiment.

Figure 4 is a view corresponding to that of Figure 1 showing an alternative embodiment.

Description of the Preferred Embodiments The boiler illustrated in Figures 1 and 2 has a double-skinned casing 1 defining a combustion chamber 2 having a single opening 3 therefrom through which a burner tube 4 projects. The burner tube 4 extends from a fan-assisted burner 5 of conventional design, mounted on an extension wall portion 6 which encloses the greater part of the front external surface 7 of the casing 1, and which communicates with a horizontal flue pipe 8, for example to permit discharge of the combustion gases through a wall to the exterior of a building in which the boiler is sited. This may be particularly convenient when the boiler is wall-mounted, rather than free-standing.

The casing 1 has a water flow chamber 9 enclosed between its inner and outer walls 10 and 11 respectively.

Water flows into the water flow chamber 9 through an inlet 12 and is led via a channel section 9a, inserted into the chamber 9 during manufacture, to a low point therein. The heated water leaves through an outlet 13 at the opposite end of the chamber. It will be appreciated that the actual positions of the inlet and outlet will be determined according to convenience of access, with the proviso that the outlet should be located near to the top of the chamber 9.

Within the combustion chamber 2, the burner tube 4 is surrounded by a flat baffle plate 14 which serves to deflect the escaping combustion gas flow away from the burner and into contact with the internal surface of the casing 1.

The gases leave the combustion chamber 2 through the annular space surrounding the burner tube 4 in the opening 3.

In the alternative embodiment shown in Figure 3, the extension wall portion 6 is extended to meet a second extension wall 15 which encloses the external surface of the top wall 16 of the casing 1. The horizontal flue is replaced by a vertical flue 17 connected to the wall 15.

The inlet water pipe 12 is shown in an alternative lower position on the casing, while the outlet water pipe 13 is located higher up on the casing, also as a side entry. In this embodiment, an even greater heat transfer area is presented, giving higher thermal efficiency for the boiler.

In the alternative embodiment shown in Figure 4, like parts have the same reference numuers as the previous drawings. The drawing shows our heat exchanger with a flue-way inserted. This enables a conventional vertical flue to be fitted in situations where the boiler is wall mounted with the burner in an opening in a wall.

A degree of draught control is achieved by providing an opening in the extension wall which allows air to be drawn into the flue-way in a similar manner to an "open flue" boiler.

In all three embodiments, access to the interior of the combustion chamber may be gained by removing the wall portion 6, and with it the burner 5, leaving the opening 3 clear. The baffle plate 14 may be fixed permanently to the interior wall of the combustion chamber, or removably mounted, preferably in segments which can be withdrawn from the chamber 2 through the opening 3.

Claims

CLAIMS:

1. A boiler comprising a casing having an inner wall defining a combustion chamber and an outer wall coextensive therewith, with an enclosed water-flow chamber between the walls, a water inlet and a water outlet for the water-flow chamber, a burner extending into the combustion chamber for introducing burning fuel thereinto, and an outlet from the combustion chamber for escape of the combustion gases.

2. A boiler according to Claim 1 and in which there is a single opening through the casing into the combustion chamber, the burner extending through the opening and the combustion gases escaping through the opening around the burner.

3. A boiler according to Claim 2 in which means are provided outside the combustion chamber for causing the escaping combustion gases to pass over a portion of the outer wall of the casing.

4. A boiler according to Claims 1 to 3 in which the burner and gas outlet are coaxial.

5. A boiler substantially as described herein with reference to and as illustrated in Figures 1 and 2, Figure 3 or in Figure 4 of the accompanying drawings.