US2916032A - Air heating apparatus - Google Patents

Description

Dec. 8, 1959 J. A. KITCHEN V AIR HEATING APPARATUS Filed oct. 1o,` 1957 2 Sheets-Sheet l Deer. 8, 1959 J. A. KITCHEN 2,916,032

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I O E I`- ooo l O" "T ooo O N o o o I- J S \7 Flgz E I United States i Patent AJR HEATING APPARATUS John A. Kitchen, Markham, Ontario, Canada, assignon by mesne assignments, to Lucas-Rotax Limited, Ontario, Canada Application October 10, 1957, Serial No. 689,438

Claims priority, application Great Britain October 11, 1956 1 Claim. (Cl. 126-116) This invention has for its object to provide in an eicient and compact form, an apparatus for heating air to be used for room-warming or other purposes.

An apparatus in accordance with the invention comprises a gaseous or liquid fuel combustion chamber, a tubular heat exchanger in direct connection with the combustion chamber, a chest on one side of which the combustion chamber and heat exchanger are mounted, and fuel and combustion-air supply means contained in the chest, the arrangement being such that the chest can be mounted over an aperture in one side of an air duct with the combustion chamber and heat exchanger extending into the duct.

In the accompanying drawings, Figures 1 and 2 are sectional side elevations in planes which are mutually at right angles, of an apparatus embodying the invention and adapted for combustion of gaseous fuel, Figure 1 being taken on the line 1-1 of Figure 2.

In the example illustrated by the drawings, the combustion chamber a consists of a hollow metal casting having air-heating fins b extending from its outer surface. Parallel and in communication with the combustion chamber is formed or connected an exhaust gas manifold c, and to this manifold is connected the heat exchanger. The latter comprises a plurality of tubes d each bent to a zig-zag form and having fiat heat-trans mitting metal plates e combined therewith. The tubes and plates are arranged parallel with each other in planes parallel with the direction of ow of the air to be heated. At one end the tubes are attached to the above mentioned monifold c. At their other ends they are connected to another exhaust gas manifold f.

The combustion chamber and heat exchanger are mounted on one side of a chest g which is divided by partitions g to form a plurality of separate compartments. In the compartment h is contained a fuel gas reservoir which is supplied through a pipe j under the control of any convenient valve j', a box k which contains electrical ignition apparatus for producing sparks at a sparking gap m in the combustion chamber, an air supply fan n and an electric motor o for driving the fan. Air is conveyed from the outer atmosphere to the compartment h through a perforated pipe p contained in a second compartment q situated alongside the first compartment, this pipe surving to muiie the sound of the ingoing air.

A third compartment r in the chest situated beneath the iirst mentioned compartment has connected to it the second manifold f above mentioned, and this compartment serves as an exhaust gas cushion. This compartment is also provided at its lower part with a drain s,

through which condensation can be discharged. A fourth compartment t situated alongside the first compartment contains another perforated pipe u which conveys the exhaust gases from the third compartment to the atmosphere, this pipe serving as an exhaust gas muier.

The combustion apparatus is of the so-called pulsatory type. The fuel gas is admitted from the reservoir i to the combustion chamber through a freely movable valve v, and the air is admitted from the compartment h through a similar valve w. Preferably the gas and air are mixed before entering the combustion chamber in an antechamber x which is separated from the combustion chamber by a llame trap y. With ignition of the mixture in the combustion chamber, the eiect of the rise of pressure in this chamber is to close the valves v, w. When this pressure falls below that of the gas in the reservoir i and air in the compartment h the valves reopen and allow a further quantity of gas and air to pass, combustion being maintained by continued intermittent supplies of gas and air in known manner.

The arrangement is such that the chest g can be secured through the medium of flanges g2 on the exterior of a wall forming one side of a duct z along which flows the air to be heated, with the combustion chamber and heat exchanger extending through an aperture in the wall into the duct. When the apparatus is in use, the air first flows over the heat exchanger, and then over the combustion chamber, from both of which parts it receives the required heat. From the air duct the heated air is distributed through other ducts to the rooms to be warmed.

The apparatus above described is adapted for combustion of gaseous fuel. The invention is not however restricted to such use, as it may be adapted to utilise a liquid fuel by employing any conventional means for vaporising or nebulising the fuel, such as a carburetor, heated vaporiser, or spraying nozzle.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

An apparatus for heating air flowing through an air duct, comprising in combination with an elongated combustion chamber of the pulsatory type having at one end pressure-responsive inlet Valves by which fuel and combustion-air under pressure are admissible to said combustion chamber, and which are arranged to be opened by the pressures of the fuel and combustion-air, and to be closed by the pressure of combustion within said combustion chamber, an elongated exhaust gas manifold communicating with said combustion chamber 'and situated at one side thereof in parallel relationship therewith, a second exhaust gas manifold spaced from the first mentioned manifold, a tubular heat exchanger interconnecting the two manifolds, a chest on one side of which said combustion chamber, exhaust gas manifolds, and heat exchanger are mounted, and which is provided with means whereby said chest can be secured over an aperture in one side of the air duct with said chest outside the duct, and with said combustion chamber, exhaust gas manifolds, and heat exchanger within the duct, partitions dividing the interior of said chest into four compartments, fuel and combustion-air supply means which are mounted in a rst compartment of said chest, and from which fuel and combustion-air have Patented Dec. 8, 1.95.9 n

rchest'to' conveyexhas't'gas to the outer atmosphere and to serve as an exhaust gas muer.

References Cited in the file of this patent UNITED STATES PATENTS Mueller Nov. 18, 1941 Frantz Dec. 30, 1941 May 12, 1953 Jaye et a1. -;L Nov. 10,1953V

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