AN AIR HEATING APPARATUS

Abstract: An apparatus for heating air, comprising a substantially cylindrical housing, including means for conducting the air to be heated therethrough and means for heating said air, the latter means including at least one hot-water reservoir arranged throughout the major part of the length of said housing. Said reservoir includes a supply and a discharge pipe and means for heating the water in the at least one reservoir. The ratio of the outside diameter to the length of the reservoir ranges between 1:3 and 1:30.

Description: The present invention relates to an apparatus for heating air, comprising a substantially cylindrical housing, means for conducting air to be heated through the housing and means for heating such air, said latter means comprising a hot-water reservoir arranged through the major part of the length of the housing, said reservoir including a supply and a discharge pipe, and a gas burner for heating the water in said reservoir, the outer wall of the hot-water reservoir being formed by a cylinder, said cylinder and the inner wall of the substantially cylindrical housing defining between them an annular space through which the air to be heated can be conducted, in the hot-water reservoir being comprised a central cylinder, concentric with the cylindrical outer wall, the gas burner being located at the bottom of said central cylinder, so that combustion gases may be discharged through said central cylinder. An apparatus of this type is disclosed in DE-A 2 550 014. The known apparatus comprises a hot-water reservoir of the boiler type, that is a reservoir that has a rather large water storage capacity. It is an object of the present invention to provide an economically constructed apparatus which is adapted to effect a uniform supply for heated air to the surroundings. The object set is achieved according to the present invention with an apparatus in which the ratio of the outside diameter of the hot-water reservoir to its length is between 1:3 to 1:30, the heat supply and construction being such that when water is being drained off from the reservoir, even during a prolonged period of time, the heating of freshly supplied water keeps pace therewith. In the apparatus according to the present invention, a hot-water supply is integrated in the hot-air heating system. The air is heated via the hot-water reservoir, which as it were serves as a thermal storage. This makes for a quiet control behaviour and realizes highly uniform heating. The hot-water reservoir in the apparatus according to the present invention should have a slender form in order to ensure optimum heating of the air at a low water capacity. A diameter-to-length ratio of 1:3 is a minimum condition therefor. A low water capacity is required to avoid, as is the case sometimes with conventional storage vessels, boilers and the like, that a large water supply is kept unnecessarily at the required temperature. A small reservoir with a heat supply, by means of a gas burner, such that when water is being drained off from the reservoir, even during a prolonged period, e.g. for filling a bath, the heating of freshly supplied water, keeps pace therewith, results in a highly economical construction. In the apparatus according to the invention the annular, cylindrical water reservoir forms a buffer between the combustion space and the space through which the air to be heated is passed. An embodiment of the apparatus according to the present invention will now be described, by way of example, with reference to the accompanying drawing in which such embodiment is illustrated in cross-sectional view. The embodiment of the apparatus according to the present invention shown in the drawing comprises a substantially cylindrical housing 1. The wall of the housing 1 consists of a thermally insulating material or of two thin cylinders of sheet metal between which there is sandwiched a thermally insulating material, such as glass wool or the like. Housing 1 is covered at its top by a cover 2, consisting e.g. of the same material, or built up similarly to the cylindrical housing 1. Housing 1 accommodates an annular, cylindrical hot-water reservoir 3 extending throughout the major part of the length of housing 1, e.g. from cover 2 as far as some distance from the underside of housing 1. Reservoir 3 is formed essentially by two concentric metal cylinders 4,5, cylinder 4 of smaller diameter forming the inner wall of reservoir 3 and cylinder 5 of larger diameter forming the outer wall. Within cylinder 4, forming the inner wall of reservoir 3, there is provided a space 6 serving as a discharge pipe for combustion gases. At the bottom of space 6, near the lower end of reservoir 3, there is arranged a gas burner 7 fed through a gas pipe 8, which is suitably passed through the wall of housing 1 or which is connected to an external gas pipe through the lower end of housing 1. Space 6 for combustion and subsequent discharge of combustion gases is connected to a pipe 9 passed through the cover 2 of housing 1, which pipe 9 may incorporate a damper 10. Pipe 9 may continue downwardly to adjacent burner 7, in which case pipe 9 closely contacts the inner wall 4 of reservoir 3, to ensure a good heat transfer to the water contained in reservoir 3. At the bottom of reservoir 3, there is provided a cold-water supply-pipe 11, which is passed through the wall of housing 1 in a suitable manner, while at the top of reservoir 3, a hot-water discharge-pipe 12 connects thereto, said pipe 12 being passed e.g. through cover 2. Between the outer wall 5 of reservoir 3 and the inner wall of housing 1, there is provided an annular space 13 through which air to be heated in the housing can be passed. The air to be heated is drawn in through suitable openings 14 in the wall of the housing 1 near its top end. The intake of air and its movement through space 13 may be effected e.g. by means of a blower 15 disposed at the bottom of housing 1. For collecting dust and the like, a dust filter 16 may be arranged at the bottom of housing 1 above blower 15. Housing 1 is attached, in any suitable manner, to the floor 17 of a building to be heated. The bottom of housing 1 is open and connects to a channel 18 provided in floor 17 for further transport and distribution of air heated in the apparatus. In the embodiment shown of the apparatus according to the present invention, the water in reservoir 3 is heated by means of gas burner 7. The air sucked in through openings 14 and subsequently transported through the apparatus is heated by contact with wall 5 of reservoir 3. Because the air is not heated directly by burner 7, a uniform heat supply is possible. By way of example, the following dimensions for the various parts can be mentioned. The diameter of space 6, approximately equal to the inside diameter of reservoir 3 is 12.5 cm. The diameter of the outer jacket 5 of reservoir 3 is 25 cm. The diameter of housing 1 is 50 cm at the exterior and 35 cm internally. The height of housing 1 as far as the top of cover 2 is 175 cm and the height of reservoir 3 is about 145 cm. The openings 14 are such that with the given dimensions of space 13, fan 15 transports about 250 m³ of air per hour through the apparatus. The apparatus is further provided with known per se means, not shown, for regulating the temperature of the water in reservoir 3 and for operating gas burner 7 and blower 15 in dependence on the desired functioning.

Claims: An apparatus for heating air, comprising a substantially cylindrical housing (1), means for conducting air to be heated through the housing and means for heating such air, said latter means comprising a hot-water reservoir (3) arranged through the major part of the length of the housing, said reservoir (3) including a supply (11) and a discharge pipe (12), and a gas burner (7) for heating the water in said reservoir (3), the outer wall of the hot-water reservoir (3) being formed by a cylinder (5), said cylinder (5) and the inner wall of the substantially cylindrical housing (1) defining between them an annular space through which the air to be heated can be conducted, in the hot-water reservoir (3) being comprised a central cylinder (4), concentric with the cylindrical outer wall (5), the gas burner (7) being located at the bottom of said central cylinder (4), so that combustion gases may be discharged through said central cylinder, characterized in that the ratio of the outside diameter of the hot-water reservoir(3) to its length is between 1:3 to 1:30, the heat supply and construction being such that when water is being drained off from the reservoir, even during a prolonged period of time, the heating of freshly supplied water keeps pace therewith.

Inventors: VAN HEEL, JOANNES MARIE
Applicants: VAN HEEL, JOANNES MARIE
Application year: 1986
Main classification: F24H6
IPC codes: F24H6