IE55529B1

IE55529B1 - Domestic back boiler

Info

Publication number: IE55529B1
Application number: IE233684A
Authority: IE
Original assignee: Sullivan Richard J
Priority date: 1984-09-13
Filing date: 1984-09-13
Publication date: 1990-10-10
Also published as: IE842336L; GB8522616D0; GB2165351B; GB2165351A

Description

This invention relates to a domestic back boiler adapted to fit within a fireplace. A prior boiler of this kind is described in published OK Patent Application 2 109 537A.

It is an object of the present invention to provide an improved heat-exchanging arrangement for such a boiler.

Accordingly, the present invention provides a domestic back boiler adapted to fit within a fireplace, the boiler having a hollow back portion, a plurality of upright hollow fins projecting forwardly of the back portion and communicating with the interior of the hollow back portion, the fins being widest at the rear and tapering towards their front edges and being sloped forwardly in the upward direction to define therebetween a plurality of forwardly sloped flues, the flues having a substantially constant cross-section along their length. 3 3 Preferably, the fins have a generally triangular cross-section, whereby the flues also have a generally triangular cross-section being narrowest at their rear. 5 10 The advantage of the invention is that as flames and hot gases tend to rise vertically, when they enter the sloped flues they are forced or wedged against the sides of the flues which converge towards the rear. This gives improved heat transfer to water contained within the fins. Furthermore, as the cross-section area of the flues does not substantially alter from bottom to top, the flues do not narrow in the upward direction thereby minimising any "venturi" effect.

Preferably a removable cover is provided against the front edges of the fins which closes off the front of the flues. An adjustable damper may also be provided at the top of the flues to open or close the latter to a desired 15 4 extent, thereby varying the heat output to the water contained in the boiler.

The back boiler may be of “wrap-around" construction with hollow side cheeks as in GB 2,109,573A, in which case the hollow back portion communicates at each side with a respective cheek, the hollow back portion, side cheeks and fins all containing water in use. Alternatively, the hollow side cheeks may be omitted to facilitate installation in cases where the existing fireplace cannot be removed or where the fireplace opening is small. In either case* suitable internal baffles are provided to promote efficient circulation of water within the boiler, and water inlet and outlet tappings are provided for connection to the pipes of a water heating system.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a partly cut away perspective view of a back boiler according to the invention, Figure 2 is a plan view of the boiler of Figure 1, Figure 3 is a vertical section of the boiler taken on line 3-3 of Figure 2, and Figure 4 is a vertical section of the boiler taken on line 4-4 of Figure 2.

Referring to the drawings, a wrap-around boiler has a pair of hollow side cheeks 10 interconnected by and in communication with a hollow back portion 11. The hollow back portion is provided with a plurality of forwardly projecting hollow parallel fins 12 which extend upwardly from the grate region 13 of the boiler. The fins 12 are open at the rear to communicate with the back portion 11, see figure 3. In use the hollow back portion 11, the side cheeks 10 and the fins 12 are all filled with water, and as mentioned hereinbefore suitable internal baffles are provided in the hollow regions to promote the efficient circulation of the water in the boiler. Water inlet and outlet tappings are also provided in conventional manner for connection to the pipes of a water heating system. The baffles and tappings are not shown in the drawings.

It is to be understood that in Figure 1 the left hand cheek 10 is not shown in order that details of the fins 12 are not obscured.

The fins 12 are of generally triangular cross-section, being widest at the rear where they communicate with the back portion 11 and tapering towards their front edges 14. The fins 12 are of substantially constant cross-section along their length from bottom to top, and slope forwardly in the upward direction, see Figure 4.

By this means there are defined between the fins 12 a plurality of flues 15 which also slope forwardly in the upward direction, and have a constant generally triangular cross-section along their length from bottom to top. The flues are widest at the front and narrowest at their rear 16. β As mentioned above, the advantage of the forward sloping flues is the more efficient heat transfer to the water contained therein by the "wedging" action on the rising flames and hot gases, and their 5 substantially constant cross-section substantially avoids a venturi effect. The angle, number and dimensions of the fins 12 may be selected as desired.

A multi-hole firebrick 17 may be positioned as shown in Figure 1 under the bottom of the fins 12, thus 10 permitting fresh air to enter the flues 15 via the space under the grate region 13. Air heated by the hot airbrick 17 as it passes through the holes 18 helps burning of volatiles and secondary combustion within the flues. Also, firebricks 19 may be positioned 15 adjacent each side cheek 10, the firebricks 19 being hollow as shown at 20 to allow air to pass from the front of the grate region 13 to the firebrick 17, the latter having apertures (not shown) which communicate with the hollows 20 to permit air from the 7 firebricks 19 to pass out from the holes 1Θ. The firebricks 17 and 19 are not shown in figures 2 to 4. Suitably shaped cast iron sections may be used instead of the firebricks 17 and 19.

A removable cover 21 (shown in figure 4 only) is positioned against the front edges 14 of the fins 12 to close off the front of the flues 15. The cover 21 extends substantially fully between the side cheeks 10 and for substantially the full height of the flues 15. The cover 21 10 is retained in position by a bent-over top portion 22 which hangs on projections 23 extending inwardly from each side cheek 10.

A sliding damper 24 is also provided which extends substantially fully between the side cheeks 10. The damper 15 rests upon a further pair of projections 25 extending inwardly from each side cheek 10 and also upon the top portion 22 of the cover 21. By sliding the damper 24 forwardly or rearwardly as desired the top of the flues 15 may be opened or closed to a desired extent.

The invention is not limited to the embodiment described herein which may be modified or varied without departing from the scope of the invention.

Claims

1. A domestic back boiler adapted to fit within a fireplace, the boiler having a hollow back portion, a plurality of upright hollow fins projecting forwardly of the back portion and communicating with the interior of the hollow back portion, the fins being widest at the rear and tapering towards their front edges and being sloped forwardly in the upward direction to define therebetween a plurality of forwardly sloped flues, the flues having a substantially constant cross-section along their length.

2. A back boiler as claimed in claim 1, wherein the fins have a generally triangular cross-section, whereby the flues also have a generally triangular cross-section being narrowest at their rear.

3. A back boiler as claimed in claim 1 or 2, wherein a removable cover is provided against the front edges of the fins which closes off the front of the flues. 9

4. A back boiler as claimed in claim 1, 2 or 3, further including an adjustable damper at the top of the flues to open or close the latter to a desired extent.

5. 5. A back boiler as claimed in any preceding claim, further including a pair of hollow side cheeks which communicate with the hollow back portion.

6. A domestic back boiler according to any preceding claim, which includes means for introducing a supply of 10 air below the bottom of the fins, thereby permitting heated fresh air, in use, to enter the flues via -a space under the grate region.

7. A domestic back boiler according to claim 6 wherein said means comprises a firebrick or cast Iron section 15 having a plurality of holes extending therethrough, positioned below the bottom of the fins.

8. A domestic back boiler according to claim 1, substantially as described herein with reference to the accompanying drawings. F.R. KELLY & CO., AGENTS FOR THE APPLICANTS.