GB2119075A

GB2119075A - Space heating apparatus and duct

Info

Publication number: GB2119075A
Application number: GB08311522A
Authority: GB
Inventors: Raymond Bradley; Charles Henry Eustace
Original assignee: SONNING HEATING Co LIMITE
Current assignee: SONNING HEATING Co LIMITE
Priority date: 1982-04-28
Filing date: 1983-04-27
Publication date: 1983-11-09
Also published as: GB8311522D0; GB2119075B

Abstract

A duct (1) for space heating apparatus of the kind comprising a closed loop of ducting suspended below the ceiling or roof of a building and in which a gaseous fluid is circulated as a heating medium. The duct (1) comprises an outer casing and means (11, 51) dividing the interior of the casing into parallel longitudinally extending portions (12, 13). Carried on a mounting pipe 22 are a fan or blower means (24, 62) for circulating heating medium through said closed loop and a burner (23) mounted externally of the ducting (1) upstream of the fan or blower means (24, 62) and firing directly into the ducting (1) towards the lower pressure side of the fan or blower means. <IMAGE>

Description

SPECIFICATION Space heating apparatus and duct This invention relates to space heating apparatus and to ducts for use therein.

Space heating apparatus is known which comprises a closed loop of ducting which is adapted to be suspended below the roof or ceiling of a building and in which air is circulated as a heating fluid, the heating effect being provided by radiation from the surface of the ducting. Generally convection suppressor plates or shields are provided along the two sides of the ducting to minimise convection flow of ambient atmosphere about the ducting and heat insulation is provided above the ducting to prevent radiant heat loss upwardly of the ducting.Usually the ducting is so arranged that the loop has parallel portions in which the heating fluid travels in opposite directions and, in use, the ducting is located at such a height above ground level and at such spacing relative to the dimensions of the area to be heated that the beams of radiant heat overlap above ground level to provide a substantially uniform heating effect. Most commonly the said parallel portions of ducting are spaced apart although it has also been proposed to provide ducting comprising a plurality of circular section tubes which are arranged side by side in close juxtaposition and in which the heating fluid travels in opposite directions.Suitable fan means is usually provided for circulating the heating fluid through said closed loop and the heating fluid is usually heated by means of a heat exchanger located within the ducting or by mounting a suitable gas or other burner within the ducting so that the gaseous products of combustion are circulated through said closed loop.

The present invention has as its object to provide a duct for space heating apparatus of the kind referred to above which is of simple and robust construction and which is efficient in use, as well as space heating apparatus incorporating such a duct.

The present invention provides a duct for space heating apparatus of the kind comprising a closed loop of ducting adapted to be suspended below the ceiling or roof of a building and in which a gaseous fluid is circulated as a heating medium, the duct comprising an outer casing and means dividing the interior of the casing into parallel longitudinally extending portions.

According to a first embodiment the casing of the duct is of sheet metal construction and comprises in its position of use, a top wall, a bottom wall and side walls connecting the top and bottom walls. Said dividing means comprises at least one partition member, e.g., a vertical partition member which divides the interior of the duct into two equal portions and said side walls or a part thereof are so arranged that the external surfaces thereof are directed outwardly and downwardly with respect to said partition member. Said top wall may be of greater lateral extent than said bottom wall and each of said side walls may, at least for the most part, extend downwardly and inwardly from the top wall to the bottom wall.Thus said side walls may comprise a relatively narrow vertical section extending downwardly from the top wall and a wider section which connects said vertical section to the bottom wall and which is inclined with respect to the vertical so that the external surface thereof is directed outwardly and downwardly with respect to said partition member.

Convection suppressor plates or shields may be provided on either side of the duct in conventional manner, e.g., so as to extend outwardly and downwardly from adjacent the lower edges of said vertical side wall sections. Likewise, in conventional manner, suitable heat insulation may be provided over the top wall of the duct. Said convection suppressor plates or shields may be formed from sheet metal and each may comprise a convection suppressor portion which extends outwardly and downwardly from adjacent the lower edge of a said vertical side wall section, an intermediate portion which is secured, e.g., welded to the vertical side wall section and which extends upwardly beyond the upper surface of the top wall and an inturned flange portion which with the top wall defines a channel for receiving and locating suitable heat insulating material.

According to another embodiment of the present invention the outer casing of the duct is substantially D-shaped in cross-section with a substantially planar top wall and a substantially semi-cylindrical wall around the sides and bottom of the duct in the position of use of the duct and the dividing means comprises a vertical partition member extending longitudinally of the casing and dividing the interior thereof into two equal portions. Again convection suppressor plates or shields may be provided along either side of the duct, e.g., so as to extend outwardly and downwardly from the longitudinal side edges of said top wall and suitable heat insulation may be provided over said top wall.

According to a further embodiment of the present invention the outer casing of the duct is of tubular construction and said dividing means is also of tubular construction and is mounted within the outer casing to provide a first fluid passage, e.g., of annular or part annular form, between the outer casing and the dividing means and a second fluid passage within the tubular dividing means. The tubular dividing means may be mounted concentrically within the tubular outer casing but preferably the tubular dividing means is mounted eccentrically within but out of contact with the tubular outer casing so that the longitudinal axis of the tubular dividing means is substantially vertically above and parallel to the longitudinal axis of the tubular casing in the position of use of the duct.Preferably suitable heat insulating material, such as vermiculite, is provided between the tubular outer casing and the tubular dividing means so as to extend around the upper part of the tubular dividing means. To this end the dividing means may comprise partition walls which extend substantially horizontally on either side of the tubular portion of the dividing means, e.g., so that said partition walls extend radially of the tubular casing, said partition walls dividing said first passage into an upper part containing said heat insulating material and a lower part which forms a passage for heating fluid. Again suitable convection suppressor plates or shields may be provided along either side of the duct, e.g., so as to extend downwardly and outwardly of the outer casing from about the level of said partition walls.The said tubular outer casing and/or said tubular dividing means may be of spirally wound hollow cylindrical or other suitable construction.

According to a yet further embodiment of the present invention the casing of the duct is of sheet metal construction and comprises, in its position of use, a top wall a bottom wall which is arcuate laterally of the duct so as to be higher at the sides than in the centre, side walls connecting the top and bottom walls and a, preferably vertical, position member dividing the interior of the duct into two, preferably equal, portions. Preferably the top and bottom walls are substantially parallel and are both arcuate laterally of the duct. As in the previous embodiments, connection suppressor plates or shields may be provided on either side of the duct, e.g., so as to extend outwardly and downwardly from the lower edges of said side walls and which may be formed integrally with the side walls and/or suitable heat invention may be provided and said top wall.

The duct may be formed in sections of predetermined length and each section may have at each end thereof outwardly directed flanges whereby it can be connected to another similar section orto other portions of space heating apparatus.

The present invention also provides space heating apparatus comprising a closed loop of ducting adapted to be suspended below the ceiling or roof of a building and means for circulating a gaseous heating medium through said closed loop, the closed loop comprising a duct according to the present invention the interior of which is divided by dividing means into parallel longitudinally extending portions through at least one of which said heating fluid is passed in one direction and through at least another of which the heating fluid is passed in the opposite direction.

Preferably the space heating apparatus of the present invention includes fan or blower means for circulating gaseous heating medium through said closed loop and a gas or other suitable burner which is mounted externally of the ducting but which fires directly into the ducting. Preferably the burner is so mounted that the flame therefrom will be directed inwardly and longitudinally of the ducting in the direction of flow of heating medium therethrough.

The burner may be a blown gas burner of the kind wherein combustion air is supplied to the burner under pressure and the burner may be located upstream of the fan or blower means so that the flame from the the burner is directed towards the low pressure side of the fan or blower means.

The present invention will be more particuiarly described with reference to the accompanying drawings, in which: Figure 1 is a plan view of one embodiment of space heating apparatus according to the present invention, Figure 2 is a side elevation of the apparatus of Figure 1, Figure 3 is a plan view on a larger scale of the burner and fan portion of the apparatus of Figures 1 and 2, Figure 4 is a side elevation of the portion shown in Figure 3, Figure 5 is a perspective view on a yet further enlarged scale of a control baffle section of the portion of the apparatus shown in Figures 3 and 4, Figure 6 is a perspective view of a burner section of the portion of the apparatus shown in Figures 3 and4, Figure 7 is a perspective view on the same scale as Figures 5 and 6 of a section for joining the section of Figure 6 to a fan casing, Figure 8 is a perspective view of a joining section for joining the sections shown in Figures 5 and 6 with a duct according to a first embodiment of the present invention, Figure 9 is a fragmentary perspective view of a duct according to a first embodiment of the present invention, Figures 10 and 11 are elevation and plan views respectively, of space heating apparatus according to another embodiment of the present invention, Figure 12 is an end elevation of a duct section used in the apparatus of Figures 10 and 11, Figure 13 is a plan view of space heating apparatus according to a further embodiment of the present invention.

Figure 14 is a side elevation of the apparatus of Figure 13, and Figure 15 is an end view of a duct section used in the apparatus of Figures 13 and 14.

Referring to Figures 1 to 9 of the drawings, and in particularto Figures 1 to 4, itwill be seen that a space heating apparatus of a first embodiment of the present invention comprises a closed loop of ducting 1 connected by a substantially Y-shaped joining section 2 to a burner section 3 and a baffle section 4 which are arranged in parallel, the other ends of the burner section and baffle section being connected through a fan casing 5 housing a fan (not shown) driven buy a motor 6.

The closed loop of ducting 1 comprises a plurality of duct sections 7 of the kind shown in figure 9. As will be seen from Figure 9 the duct comprises, in its position of use, an outer casing comprising a top wall 8, a bottom wall 9 and side walls 10 connecting the top wall 8 and the bottom wall 9. Each of the side walls 10 comprises a narrow vertical section 10 extending downwardly from the top wall 8 and a very much wider section lOb connecting the wall section 10a to the bottom wall 9. Avertical partition member 11 extends longitudinally of the duct and divides the interior of the duct into two equal portions 12 and 13. Outwardly directed flanges 14 are provided at the end of each duct section to facilitate the connection of the duct sections, as by means of bolts or the like, to one another orto other sections of the heating apparatus. Convection suppressor plates or shields 15 extend outwardly and downwardly on either side of the duct from adjacent the lower edge of the side wall sections 10a and have vertical extension portions 1 5a whereby they are secured, e.g., welded, to the side wall sections 10a and which extend upwardly above the top surface of the top wall 8 and are provided with inturned flange 16 for locating suitable heat insulating material (not shown) above the top wall 8. The duct is of sheet metal construction and is formed in two equal parts which are connected together along the vertical centre line of the duct as by means of seams 17.

Brackets 18 attached to the seam 17 are provided for use in suspending the duct, e.g., through the intermediary of suitable stays or supports, from a ceiling or roof.

The joining section 2 is formed at one end to the the same cross sectional shape as the duct sections 7 and the interior thereof, like the duct sections 7, is divided by an internal partition member (not shown).

At its other end the joining section 2 divides into two substantially square section duct portions 19 and 20.

The duct portion 19 has a sidewall 21 which is angled with respect to the vertical centre line of the joining section 2 and which has a flanged mounting pipe 22 extending therefrom for mounting a blown gas burner 23 (Figure 3) the actual burner of which is received within the pipe 22 so that the flame from the burner will be directed inwardly and longitudinally of the burner section 3 substantially along the longitudinal axis thereof in the direction of flow of heating medium therethrough. The blown gas burner 23 comprises a fan 24 driven by an electric motor 25 for the supply of combustion air and suitable gas conduits and governors 26 for the supply of gas to the burner. The burner section 3 connects to the low pressure side of the fan casing 5 whilst the baffle section 4 is connected to the high pressure side of the fan casing 5.Thus the gas burner 23 is located upstream of the fan and is in a low pressure part of the system. Referring now to Figure 5 it will be seen that the baffle section 4 comprises a main duct portion 27 and vent portions 28 and 29 which extend upwardly and downwardly respectively from the main duct portion 27. The vent portions 28 and 29 both discharge to atmosphere. Mounted within the baffle section 4 are a series of baffles 30,31 and 32 which are movabie between open and closed positions by a system of levers 33. The upper vent portion 28 has an aperture 34 in an end wall thereof above the baffle 30 and a bleed conduit 35 from the burner section 3 is connected to the said end wall of the vent portion 28 around the aperture 34 so as to connect the interior of the burner section 3 with the interior of the vent portion 28.A bleed control 36 is provided for controlling the amount of heating fluid hled from the apparatus when the apparatus is in use, the bleed control being suitably set so as to compensate for the fresh heating fluid which is being introduced into the apparatus so as to prevent a build up of pressure within the apparatus. In the normal heating mode of the heating apparatus the baffles 30,31 and 32 are in the positions shown in Figure 5 with the baffles 30 and 32 in their closed positions so as to close the vent portions 28 and 29 and with the baffle 31 in its open position so that heating fluid can circulate around the closed loop 1.

On start-up of the heating apparatus it is necessary to first purge the apparatus to ensure that there in no accumulation of gas therein. Accordingly at start-up the baffles 30,31 and 32 are repositioned so that the vent portions 28 and 29 are open whilst the main duct 27 is closed downstream of the vent portions 28 and 29 by the baffle 31. The fan is then operated for a short period to purge any gas from the apparatus.

The burner section 3 is connected to the fan casing 5 by the section shown in Figure 7 which comprises a main portion 37 which connects to the burner section 3 and a tubular extension portion 38 which connects to the inlet of the fan casing 5. At its end opposite the burner and fan assemblies the closed loop 1 is completed by a return section 39 providing a curved end wall 40 around which the heating fluid flows from the duct portion 12 into the return duct portion 13.

It will be understood that whilst the space heating apparatus illustrated in Figures 1 and 2 comprises only a single closed loop 1 connected to the burner section 3 and baffle section 4 by a joining section 2, the apparatus could, if desired, comprise a plurality of such closed loops 1 which were connected to the burner section 3 and baffle section 4 by suitable headers. Likewise, the closed loop 1 need not extend simply linearly as shown but can by the use of suitable bend sections, e.g., suitable right-angle bend sections, include portions which extend at an angle to one another, e.g., so that the closed loop 1 is in the form of an L-shape or a U-shape when viewed in plan.

Because the major part of the external surface area of the side walls 10 is provided by the side wall portions lOb and the external surfaces of these side wall portions 10b are directed outwardly and downardly with respect to the vertical partition member 11, the heating apparatus and duct of the present invention provides a high degree of heat efficiency.

Moreover, the construction of the duct provides a robust and rigid structure which is simple to manufacture in sheet metal. The mounting of the burner 23 externally of the apparatus and so that the flame therefrom is directed inwardly and longitudinally of the burner section 3 substantially along the longitudinal axis thereof provides ready access to the burner for servicing and contributes to the heating efficiency of the apparatus.

The apparatus illustrated in Figures 10 to 12 is similar to that illustrated in Figures 1 to 9 except for the construction of the ducting 1 and accordingly like reference numerals have been used to indicate like parts.

As will be seen from Figures 10 to 12 the ducting 1 comprises a tubular outer casing 50 within which is mounted dividing means comprising an eccentric tubular dividing member 51 the longitudinal axis of which is substantially vertically above and parallel to the axis of the outer casing 50 in the position of use of the ducting. The dividing means further comprises partition walls 52 which extend substantially horizontally between the outer surface of the tubular dividing member 51 and the inner surface of the tubular outer casing 50 and divide the annular space between the outer casing 50 and tubular dividing member 51 into an upper part 53 which is filled with a suitable heat insulating material 54 and a lower part which forms a fluid passage 55. Thus the heat insulating material 54 extends around the upper part of the tubular dividing member 51.

The interior of the tubular dividing member 51 forms a passage for return fluid and is connected to the inlet end of the burner section 3 whilst the fluid passage 55 is connected to the outlet end of the baffle section 4 by an elbow section 56 and annular or part-annular chamber 57.

Both the burner section 3 and baffle section 4 are of double-skin tubular construction comprising an outer skin 58 and an inner skin 59 with suitable heat insulating material 60 interposed therebetween.

The burner section 3 and baffle section 4 are connected through an end housing 61 on which is mounted the fan motor 6. The fan 62 is mounted in the inlet end of the baffle section 4 and is driven by the motor 6 by way of a belt and pulley transmission 63 and a shaft 64.

The apparatus of Figures 13 to 15 is similar to that illustrated in Figures 1 to 9 except for the construction of the ducting 1 and accordingly like reference numerals have been used to indicate like parts.

As will be seen from Figures 13 to 15, the ducting 1 is of sheet metal construction and comprises, in its position of use, top and bottom walls 65, 66 respectively which are substantially parallel and which are arcuate laterally of the duct 1 so as to be higher at the sides than in the centre, side walls 67 connecting the top and bottom walls 65,66 and a vertical partition member 11 which extends longitudinally of the duct and divides the interior of the duct into two equal portions 12 and 13. The connection suppressor plates of shields 15 are, as in the Figure 1 embodiment, extended upwards and provided with inturned flanges 16 for locating suitable heat insulating material 68 which extends overthe upper surface of the top wall 65.The convection suppressor plates or shields 15 are inturned flanges 16 may be formed integrally with the side walls 67 or may be formed separately and secured, e.g. welded, to the side walls 67.

The joining section 2 of the embodiment of Figures 13 to 15 is substantially box-shaped and has an arcuate opening in one end wall 69 thereof which corresponds to the cross-sectional shape of the interior of the duct 1 and around which the adjacent duct section is secured by means of the flange 14 at that end of the duct section. The other end wall 70 of the joining section 2 has the burner section 3 and baffle section 4 connected thereto, rectangular apertures (not shown) being provided in the end wall 70 to communicate the joining section 2 with the burner section 3 and baffle section 4. The interior of the joining section 2 is, like the duct 1, divided into two portions by a vertical partition member 71 which is aligned with and forms an extension of the vertical partition member 11 of the duct 1.

The duct 1 of the embodiment of Figures 13 to 15 has advantages in that it is relatively simple and cheap to facilitate from sheet metal and is efficient in use.

The burner has not been shown in Figures 10 and 11 and Figures 13 to 15 but is of the same kind and is mounted on the flanged mounting pipe 22 in the same manner as in the previous embodiment.

Claims

1. A duct for space heating apparatus of the kind comprising a closed loop of ducting adapted to be suspended below the ceiling or roof of a building and in which a gaseous fluid is circulated as a heating medium, the duct comprising an outer casing and means dividing the interior of the casing into parallel longitudinally extending portions.

2. A duct according to claim 1, wherein the duct is of sheet metal construction and comprises, in its position of use, a top wall, a bottom wall and side walls connecting the top and bottom walls.

3. A duct according to claim 2, wherein said dividing means comprises a partition member which divides the interior of the duct into two substantially equal parts.

4. A duct according to claim 3, wherein said partition member is a vertical partition member.

5. A duct according to claim 4, wherein said side walls are so arranged that the external surfaces thereof are directed outwardly and downwardly with respect to said partition member.

6. A duct according to claim 5, wherein said top wall is of greater lateral extent than said bottom wall and each of said side walls, at least for the most part, extend downwardly and inwardly from the top wall to the bottom wall.

7. A duct according to claim 6, wherein said side walls comprise a relatively narrow vertical section extending downwardly from the top wall and a wider section which connects said vertical section to the bottom wall and which is inclined with respect to the vertical so that the external surface thereof is directed outwardly and downwardly with respect to said partition member.

8. A duct according to claim 2,3 or 4, wherein said bottom wall is arcuate laterally of the duct so as to be higher at the sides than in the centre.

9. A duct according to claim 8, wherein the top and bottom walls are substantially parallel and are both arcuate laterally of the duct.

10. A duct according to claim 1, wherein the outer casing of the duct is substantialy D-shaped in cross-section with, in its position of use, a substantially planar top wall and a substantially semicylindrical wall around the sides and bottom of the duct and wherein the dividing means comprises a vertical partition member extending longitudinally of the casing and dividing the interior of the casing into two substantially equal portions.

11. A duct according to any one of the preceding claims, wherein convection suppressor plates or shields are provided which extend, in the position of use of the duct, outwardly and downwardly on either side of the duct.

12. A duct according to any one of the preceding claims 2 to 11,wherein heat insulating material is provided over the top wall of the duct.

13. A duct according to claims 11 and 12, wherein said convection suppressor plates or shields are extended upwardly beyond the upper surface of the top wall and are provided with inturned flange portions which with the top wall defines a channel for receiving and locating said heat insulating material.

14. Aduct according to claim 1,wherein the outer casing of the duct is of tubular construction and said dividing means is also of tubular construction and is mounted within the outer casing to provide a first fluid passage between the outer casing and the dividing means and a second fluid passage within the tubular dividing means.

15. A duct according to claim 14, wherein the tubular dividing means is mounted eccentrically within but out of contact with the outer casing so that the longitudinal axis of the tubular dividing means is substantially vertically above and parallel to the longitudinal axis of the tubular casing in the position of use of the duct.

16. A duct according to claim 14 or 15, wherein heat insulating material is provided between the tubular outer casing and the tubular dividing means so as to extend around the upper part of the tubular dividing means.

17. A duct according to claim 16, wherein the dividing means comprises partition walls which, in the position of use of the duct, extend substantially horizontally on either side of the tubular portion of the dividing means so as to divide said first passage into an upper part containing said heat insulating material and a lower part which forms a passage for heating fluid.

18. A duct according to any one of claims 14 to 17, wherein convection suppressor plates or shields are provided which extend outwardly and downwardly on either side of the duct.

19. Space heating apparatus comprising a closed loop of ducting adapted to be suspended below the ceiling or roof of a building and means for circulating a gaseous heating medium through said closed loop, the closed loop comprising a duct according to any one of the preceding claims the interior of which is divided into parallel longitudinally extending portions through at least one of which the heating fluid is passed in one direction and through at least another of which the heating fluid is passed in the opposite direction.

20. Space heating apparatus according to claim 19, comprising fan or blower means for circulating gaseous heating medium through said closed loop and a burner mounted externally of the ducting and firing directly into the ducting.

21. Space heating apparatus according to claim 20, wherein said burner is so mounted that the flame therefrom is directed inwardly and longitudinally of the ducting in the direction of flow of heating medium therethrough.

22. Space heating apparatus according to claim 20 or 21, wherein said burner is a blown gas burner of the kind wherein combustion air is supplied to the burner under pressure.

23. Space heating apparatus according to claim 20, 21 or 22, wherein the burner is located upstream of the fan or blower means so that the flame from the burner is directed towards the low pressure side of the fan or blower means.

24. A duct for space heating apparatus substantially as herein described with reference to Figures 1 to 9, Figures lotto 12 or Figures 13to 15 ofthe accompanying drawings.

25. Space heating apparatus substantially as herein described with reference to Figures 1 to 9, Figures 10 to 12 or Figures 13 to 15 of the accompanying drawings.