DE3039065C2 - Warm air heater - Google Patents

Description

The invention relates to a Warmlui't heating device according to the preamble of claim 1.

Such a device is known from DE-OS 26 19 762.

There a fan sucks the circulating air through a heat exchanger in the form of an electrically heated storage block. With the help of a controllable flap, the air flow can be controlled before it enters the heat exchanger divided and partly bypassing the heat exchanger directly into the discharge chamber, where it is reunited with the partial flow passed through the heat exchanger. The regulated circulation of air is also necessary in order to cope with the constantly changing heat dissipation capacity over the discharge time of the memory block to be taken into account.

Since such storage heat exchangers are expensive in terms of material and consumption, they are in question In the coming applications mostly burner-heated heat exchangers are used.

In a known device of this type, the fan, the combustion chamber, the heat exchanger and the The blow-out chamber is arranged one above the other in such a way that all of the air conveyed by the fan initially arrives at the combustion chamber and then flows past the heat exchanger into the exhaust chamber. Such warm air heaters have proven themselves and achieve a combustion efficiency of 89%.

A disadvantage of these known heating devices, however, is that they the circulating air with a relatively high Blow out temperature; this naturally has thermal losses and highly intermittent operation of the The warm air generator. Furthermore, there is an unfavorable temperature stratification with a relatively strong Temperature rise above the level of the to be heated

Space.

The invention is based on the object of providing a warm air heating device of the type described above To create a type that enables burner heating with high energy utilization

According to the invention, this object is achieved by the characterizing features of claim 1.
Because only part of the circulating air goes through the heat exchanger

ίο is performed, the correspondingly smaller dimensioned Burners remain in operation practically all the time.

This part of the circulating air conveyed by the fan is heated to a high level. In the blow-out chamber, which is advantageous is designed as a mixing chamber, come the

The hot main flow and the cooler secondary flow are combined again and are blown out at their mixed temperature, which is significantly below the conventional blow-out temperature.
The part of the circulating air passed through the duct is heated by the post-heat exchanger, through which the already largely cooled flue gases flow withdrawn.

It has been shown that this is an improvement the combustion efficiency to 93% and an improvement in the system efficiency by approx. 23% is possible

The channel is preferably through a partition wall in one of the combustion chamber and the heat exchanger, on the other hand, the heating chamber surrounding the post-heat exchanger is formed. Advantageously, a distributed to the control device connected to the fan, the circulating air in selectable proportions to the heat exchanger and the post-heat exchanger.

The drawing illustrates the invention using an exemplary embodiment in a schematic cross-sectional view the new warm air heating device.

The box-shaped heating device consists of a lower fan part 1, a central heating chamber 2 and an upper blow-out chamber 3. In the fan part 1, the fan 5 driven by a motor 4 is accommodated Its exhaust opening 6 is opened up into the heating chamber 2, which is otherwise through a partition 7 is separated from the fan part 1

A vertical partition 8 divides the heating chamber 2 practically into two vertical, adjacent ones Channels of different sizes, in the main channel 9 is the combustion chamber 10, in which a Burner 11 by burning a liquid or gaseous Generates fuel flue gases. These reach the heat exchanger 13 through a flat tube 12.

The flue gases are deflected here and released from the heat exchanger through the pipe socket 14.

The heat connection 14 penetrates the partition 8 and accordingly leads into the channel 15. Inside this, A secondary heat exchanger 16 is attached to the pipe socket 14 and forms a “bypass” to the main channel 9 connected, which releases the flue gases into the flue gas nozzle 17.

Between the exhaust opening 6 and the partition wall 8 is a control device for distributing the from the fan 5 promoted amount of circulating air on the channels 9 and 15 is provided. It is in the drawing only by one pivotable flap 18 indicated, but can also have any other conventional design.

The flow arrows drawn and the temperature at * illustrate how the new warm air heating device works. A - in. general larger part of the circulating air conveyed by the fan 5, for example at! 5 "C, flows through it the main channel 9, sweeps past the combustion chamber 10 and is opened in the heat exchanger 13 for example 65 ° C before it is used as a mixing chamber formed blow-out chamber 3 gets into the duct. A usually smaller part of the circulating air gets into the duct 15 and is from the post-heat exchanger arranged there with the help of the residual heat supplied to it Flue gases are heated to, for example, 18 ° C before he also enters the blow-out chamber 3. There the two partial air flows unite again, so that the strongly heated main air stream is cooled to a mixed temperature of, for example 37 ° C, with which the Air leaves the heater

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Claims (4)

Patent claims: 1. Warm air heating device with a fan, which d; e zu_erwärmende air over the heat exchanger leads into a blow-out chamber, with a connecting the fan with the blow-out chamber, the Heat exchanger bypassing channel is provided for part of the circulating air, characterized in that that the heat exchanger {13) from the flue gases from a burner-heated combustion chamber (10) is flowed through, and that a post-heat exchanger {16) is arranged in the channel (15), which lies in the flue gas flue between the heat exchanger (13) and a flue gas nozzle (17) 2. Warm air heating device according to claim 1, characterized in that the channel (15) through a partition (8) in a on the one hand the combustion chamber (10) and the heat exchanger { 13), on the other hand, the post-heat exchanger (16) enclosing heating: chamber (2) is gc-educated 3. Warm air heating device according to spoke 1 or 2, characterized in that a control device (18) connected to the fan (5) the Circulating air distributed in selectable proportions to the heat exchanger (13) and the post-heat exchanger (16) 4. Warm air heating device according to claims 1-3, characterized in that the blow-out chamber (3) is designed as a mixing chamber for the two circulating air partial flows.