STORAGE HEATERS

Abstract: A storage heater brick of an interlocking form, having projections and recesses on opposite faces. The projections are deeper than the recesses so that a stack of such bricks has air gaps between adjacent bricks. The projections are an easy fit in the recesses so that each brick beds down completely into its neighbour but the fit is sufficient to limit lateral movement. A free standing secure stack is thus provided with provision for efficient circulation of air and heat transference. Such a storage heater may then serve to heat water by way of a heat exchanger in the air flow path.

Description: Storage Reaters & Bricks Therefor This invention relates to bricks, particularly for use in an electric storage heater. Storage brick materials have a relatively low thermal conductivity and thus there is a well known problem of first getting heat into the bricks from heating elements and then getting it out to the cooling medium, which is usually air. One object of the invention is to produce a storage heater brick which can be built up in a variety of the simple bonding patterns traditional in wall building, whilst maintaining a spacing from adjacent bricks on at least two sides to allow greater heat transfer to the surrounding air. According to the present invention a storage heater brick has on opposite faces thereof projection and recess configurations whereby a plurality of such bricks can be located in predetermined relative dispositions by cooperation of said configurations of adjacent bricks, said configurations comprising projections and recesses of such extent and depth respectively that the confronting faces of two bricks so located are separated by a space, said configurations also being such that said confronting faces are maintained apart by abutment between surfaces being substantially parallel to said confronting faces. Preferably the configurations are frustoconical projections and recesses respectively, each frusto-conical projection being an easy fit inside a frusto-conical recess. The angles of the sides of the frusto-conical projections and recesses are preferably the same. Preferably the projection configuration is located on a first face of the brick and the recess configuration is located on an opposite face of the brick. In an alternative embodiment a brick comprises at least one recess and a group of projections arranged to cooperate with the corresponding recess of an adjacent brick, the sides of the projections being arranged to locate against the side of such a cooperating recess. According to another aspect of the invention, a storage heater incorporates an assembly of interlocking bricks as aforesaid, and heating means arranged to heat said bricks. Such a storage heater-may include means for drawing heated air from a space above the bricks through an air/liquid heat exchanger so providing a heat source for the liquid, which may be central heating water. A storage heater brick and a storage heater in accordance with the invention will now be described, by way of example, with reference to the accompanying drawings of which: Figure 1 shows a pictorial view of a brick; Figure 2 shows a cross-sectional view of the brick of Figure 1; Figure 3 shows a cross-sectional view of an alternative form of brick; and Figure 4 shows a schematic diagram of a storage heater. As shown in Figures 1 and 2 a brick 1 is illustratedhaving on one face two frusto-conical projections 3 and on the opposing face a recess configuration comprising corresponding recesses 5. The height of the projections is greater than the depth of the recesses and the recess diameter is such as to locate a projection without close engagement, i.e., as an easy or clearance fit between the conical walls. The bottom of each recess, face 9, and the top of each projection, face 11, provide abutment surfaces the size and position of which are such that a substantial part thereof iF close to the edges of the bricks. A wide base of support is thus provided, allowing bricks to be piled stably one above the other, in a conventional wall formation, such that there is a clearance between the confronting faces of adjacent bricks. when stacked, face 9 of the recess rests on face 11 of a projection of another brick, and, as mentioned above, there is a clearance between the sides of the projection and the sides of the recess. The position of the projections 3 and recesses 5 on each brick is such that when the bricks are stacked in a wall formation there is a gap between two adjacent bricks on the same layer. The bricks have through holes 7 between the recess 5 and the opposite projection 3 to increase the convection paths and provide ducts for housing electric elements. Figure 3 shows an alternative projection configuration to that of Figure 1. This configuration has a group of four projections 13 to each recess 15. The projections 13 and recesses 15, are shaped and disposed on each brick in a form such that a traditional "nine-inch" wall formation can be bonded with headers and stretchers. Depending upon the shape of recess 15 the projections 13 may be square or round or of other shape suitable for locating a brick and providing a stable base for subsequent layers of bricks. Figure 4 shows a storage heater 21 which incorporates the aforementioned bricks 1 of the kind shown in Figures 1 and 2. The bricks are stacked in a chamber 31 bounded by insulation 23 on the sides and top. The bricks are stacked in staggered formation so that their holes 7 are vertically aligned below access holes 25 in the insulation, the holes 25 passing from the chamber 31 through the insulation 23 to allow an electric heating element 27 to be located in selected ones of the holes 7. A vertical metal duct 33 is located inside the brickwork assembly, opening at the upper end into a space 35 above the brick core. An air/liquid heat exchanger 29 and a fan 30 are connected to the lower end of the duct 33 so that in the process of extracting heat from the heater warm air is drawn from the space 35 over the heat exchanger 29 by the fan 30. The heat thus taken from the air is used for purposes such as heating central heating water. When the electric elements are energised, air flows up through the holes 7 by natural convection and also between the bricks so assisting the distribution of heat to them which heat must otherwise pass from the elements to the bricks largely by radiation and then through the bricks by conduction. During heating the fan 30 is off and the bricks are heated by natural convection. During cooling the fan 39 is on, extracting air from the duct 33, the space 35 and thus drawing air upward through the holes 7 and between the bricks. Air is drawn into the heater through a grid on which the brick core stands, and is vented from a grille fed by the fan 30. The heat exchanger provides an optional heat sink for the heated air, it being controllable by control of the water flow. The brick core may consist of layers of, say, twelve bricks in each layer arranged in different patterns from layer to layer so as to provide a secure, interlocking, core assembly. The duct 33 is conveniently square and of side equal to the width of one brick so that a pattern can be completed in each layer. The interlocking construction of the bricks 1 provides a mutual bond and when stacked in free standing blocks as in chamber 31 to a large extent the supporting metalwork currently used in storage heaters is obviated. The free standing brick cores are able to expand and contract without developing internal stresses, brick to brick, and they are not constrained in this storage heater 21 by supporting means having different expansion coefficients. The bricks may be formed from any convenient storage brick material. The difficulty of holding to close dimensional tolerances articles manufactured by firing processes in the industrial ceramics industry is weli known. The brick of the invention-need be accurate only over the interlocking areas and thus the problem of dimensional accuracy is much reduced. When fired at high temperature storage brick materials commonly form small blisters and glassy excrescences on the surface which normally have to be removed by individual hand labour before delivery. The type of brick illustrated virtually eliminates this work as the probability of a blister forming on the small amount of interlocking surface is low.

Claims: CLAIMS 1. A storage heater brick having on opposite faces thereof projection and recess configurations whereby a plurality of such bricks can be located in predetermined relative dispositions by cooperation of said configurations of adjacent bricks, said configurations comprising projections and recesses of such extent and depth respectively that the confronting faces of two bricks so located are separated by a space, said configurations also being such that said confronting faces are maintained apart by abutment between surfaces of the cooperating configurations at positions close to the edges of the bricks, the abutment surfaces being substantially parallel to said confronting faces. 2. A brick according to claim 1 wherein said configurations are frusto-conical projections and recesses respectively, each frusto-conical projection being an easy fit inside a said frusto-conical recess. 3. A brick according to claim 1 or claim 2 wherein the projection configuration is located on a first face of the brick and the recess configuration is located on an opposite face of the brick. 4. A brick according to claim 2 wherein said projection and said recess configurations have centres in alignment. 5. A brick according to claim 1 or claim 2 wherein said projection configurations are two in number and said recess configurations are two in number, each recess having its centre aligned with the centre of a projection. 6. A brick according to claim 1, comprising at least one recess and a group of projections arranged to cooperate with the corresponding said recess of an adjacent brick, the sides of said projections being arranged to locate against the side of such a cooperating recess. 7. A brick according to claim 6 wherein said recess is square and said group consists of four individual projections each one being located to fit at the corner of a said recess. 8. A brick according to any preceding claim, having a through-hole extending between said abutment surfaces. 9. A storage heater incorporating an assembly of interlocking bricks, each according to any preceding claim, and heating means arranged to heat said bricks. 10. A storage heater according to claim 9 as appendent to claim 8, wherein the bricks are stacked so that said through holes are in vertical alignment, electric heating elements being mounted in said through holes. 11. A storage heater according to claim 10 including a space above the bricks into which heated air rises, and a vertical duct opening into said space, said duct being connected to a fan arranged to vent air drawn from said duct to the exterior of the storage heater. 12. A storage heater according to claim 10 or or claim 11, including means for drawing heated air from a space above the bricks through an air/liquid heat exchanger so providing a heat source for said liquid. 13. A storage heater brick substantially as hereinbefore described with reference to Figures 1 and 2, or to Figure 3 of the accompanying drawings. 14. A storage heater substantially as hereinbefore described with reference to the accompanying drawings.

Inventors: RODWELL, CHRISTOPHER, WILLIAMS, GEOFFREY JOHN
Applicants: THE ENGLISH ELECTRIC COMPANY LIMITED
Application year: 1982
Main classification: F24J3
IPC codes: F28D20