Electric heating fan

Abstract

The invention is directed to a heating fan (100) with an inner space (110) in which is arranged an air channel (810) which is partially made of plastic. An electric heating body (300) is arranged behind a fan (800) in an air flow direction (821). According to the invention, this fan is constructed such that a fan wheel (801) of a radial fan, which fan wheel (801) is contained in the fan (800), has two suction sides (805, 806) which are separated by a dividing wall (804). During operation, a first air flow (822) is sucked in from outside (1) through the first suction side (805) which is open to a first air inlet opening (221). The second suction side (806) is arranged in a fan space (111) of the heating fan (100) and is pneumatically connected to second air inlet openings (222). The fan is arranged in front of a ceramic heating element (301) of the electric heating body (300) so that the first air flow (822) and the second air flow (823) stream through the heating body (300).

Claims

1. A heating fan with an inner space having an air channel, comprising: an electric heating body arranged behind a fan in an air flow direction, wherein the fan has a fan wheel of a radial fan with a first suction side and a second suction side which are separated by a dividing wall, wherein the first suction side is open to a first air inlet opening through which a first air flow is sucked in from outside through the first suction side during operation, wherein the second suction side is arranged in a fan space of the heating fan, and the second suction side is pneumatically connected to second air inlet openings, and the fan is arranged in front of the electric heating body so that the first air flow and the second air flow stream through the heating body.

2. The heating fan according to claim 1, wherein a guide wall through which the fan space is formed is arranged in the inner space so that at least some of the second air flow is guided to the second suction side.

3. The heating fan according to claim 1, wherein the fan space is situated between the second suction side and the second air inlet opening so that air flows out of an inner space into the second suction side during operation of the heating device.

4. The heating fan according to claim 1, wherein the fan has an exhaust opening through which a total air flow is guided to the heating body during operation of the heating fan, and the heating body is arranged behind the exhaust side in air flow direction.

5. The heating fan according to claim 1, wherein the second air inlet opening is arranged in the rear wall.

6. The heating fan according to claim 1, wherein the first air inlet opening has a larger opening area than the second air inlet opening, wherein the first air inlet opening makes up in particular approximately 55% to 90% of the total opening area of first air inlet opening and second air inlet opening so that the mass flow of the first air flow is greater than the mass flow of the second air flow during operation of the heating fan, and the mass flow through the first opening amounts in particular to approximately 60% to 80% of the total mass flow.

7. The heating fan according to claim 1, wherein the fan wheel of the fan has first blades which are arranged toward the first suction side, and in that second blades of the fan are arranged toward the second suction side.

8. The heating fan according to claim 1, wherein the first blades and the second blades of the fan wheel are separated by a dividing wall.

9. The heating fan according to claim 1, wherein the first blades are larger than the second blades, in particular at least approximately 50% larger.

10. The heating fan according to claim 1, wherein the electric heating body is a ceramic heating element.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0031] To the accomplishment of the foregoing and related ends, certain illustrative embodiments of the invention are described herein in connection with the following description and the annexed drawings. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed and the present invention is intended to include all such aspects and their equivalents. Other advantages, embodiments and novel features of the invention may become apparent from the following description of the invention when considered in conjunction with the drawings. The following description, given by way of example, but not intended to limit the invention solely to the specific embodiments described, may best be understood in conjunction with the accompanying drawings, in which:

[0032] FIG. 1 shows the heating fan in section;

[0033] FIG. 2 shows the heating fan 100 in a sectional three-dimensional view;

[0034] FIG. 3 shows a section viewed toward the inner guide wall;

[0035] FIG. 4 shows the heating fan with its rear wall and the component parts located in the inner space;

[0036] FIG. 5 shows the heating device from the front without its front;

[0037] FIG. 6 shows the controller arranged on the inner side.

DETAILED DESCRIPTION

[0038] FIG. 1 shows a heating fan 100 arranged in a space 1. An inner space 110 in which an air channel 810 is arranged is located in the heating fan 100. In the embodiment example, the air channel 810 is made of plastic and is configured to guide a hot air flow 820. During operation of the heating fan 100, air is guided in an air flow direction 821 through the heating fan 100 or in air flow direction 821 through the air channel 810. Air flow direction 821 comes about through the operation of a fan 800 which is arranged in front of or in the air channel 810.

[0039] The fan 800 has a fan wheel 801 which is driven by a fan motor 830. The fan motor 830 has a hub 831. The fan wheel 801 has two regions. First blades 808 are arranged in the fan wheel in one region and second blades 809 are arranged on another side in another region. The first blades 808 and second blades 809 are separated by a dividing wall 804 of the fan 800.

[0040] Accordingly, operation of the heating fan produces a first air flow 822 which is sucked into the heating fan 100 through first air inlet openings 221. The first air flow 822 is generated by the first blades 808 during operation of the fan 800 on the first suction side 805. In the embodiment example, an air filter 860 is advantageously arranged on the first suction side.

[0041] A second air flow 823 is generated by the second blades 809 during operation of the fan 800. The second blades 809 which are located on a second suction side 806 suck air from a fan space 111. In the embodiment example, the fan space 111 is located between a front 210 and the second suction side 806 or the second blades 809 of the fan 800. The second air flow 823 is sucked in through second air inlet openings 222 which are arranged in the lower area of a rear wall 220 and in the upper area above a wall spacer 270 in the embodiment example.

[0042] A further spacer 270 is arranged below in the heating fan 100 in the rear wall 220 at the level of the air exhaust grating 813 only just toward the rear wall 220. Accordingly, the fan 800 conveys two air volume flows, namely, first air volume flow 822 and second air volume flow 823, during operation, i.e., when the fan motor 830 is supplied with current.

[0043] The first air volume flow 822 and the second air volume flow 823 make a total air flow 824 in air flow direction 821 just inside or downstream of the fan 800. This total air flow 824 results at least upstream of a heating block 300 which the total air flow 824 passes during operation of the heating fan 100. Accordingly, the heating block 300 is arranged downstream of the fan 800 viewed in air flow direction 821 and has an electric heating element which is a ceramic heating element 301 in the embodiment example. Therefore, a total air volume flow 824 is generated by the fan 800 and conveyed to the heating block 300 at an exhaust side 807. As is shown in FIG. 1, the fan 800 accordingly sucks a first air flow 822 through a first air outlet opening 221 and a second air flow 823 through second air inlet openings 222 via a fan space 111. The two air flows 822, 823 are then heated by the heating block 300 as total air flow 824 and given off through the air exhaust grating 813 in space 1. In an advantageous manner, the hot air flow 820 is given off obliquely downward into space 1.

[0044] Arranged in the air channel 801 upstream of the air exhaust grating 813 is an air deflector 816 which is formed by a plurality of baffles 817 arranged horizontally in the embodiment example. In the embodiment example according to FIG. 1, the air deflector 816 comprises baffles 817 which are made of plastic and which also have an angle 818 of approximately 110°.

[0045] According to FIG. 2, the heating fan 100 is shown with a suction grating 812 which is arranged toward the first blades 808 in air flow direction 821 during operation of the fan 800. The air suction grating 812 is located on the first suction side 805.

[0046] An air filter holder 861 is advantageously provided in the embodiment example. A lint filter, not shown, or a filter is inserted therein. Accordingly, the first air flow 822 which is generated by the first blades 808 is cleaned through filters and/or guided through an air suction grating 812.

[0047] Further, in the embodiment example the heating fan 100 has a cable space 290 in which a connection cable, not shown, can be wound up or stowed. Accordingly, the cable space 290 is located in the area of the air channel 810. The cable is advantageously connected to a socket terminal strip 710.

[0048] Further, the heating fan 100 has an operator control part 401 with which a controller 400 can be adjusted. A target temperature for space 1 can be set with the controller 400. In an advantageous manner and for precise control, air is supplied to the controller 400 which is arranged in the inner space 110, which takes place through the second air inlet openings 222 in the embodiment example. During operation of the device, air is sucked in through all second air inlet openings 222, flows past the controller 400 at least partially and provides the controller 400 with air from space 1. When the heating fan 100 is stationary, the controller 400 is ventilated with air from space 1 through the second air inlet openings 222 which are situated below and which are arranged in the area of cable space 290. The air flows through convection from the bottom, i.e., the second air inlet openings 222 arranged in the area of the cable 290, to the controller where it passes out of the device again in the vicinity of the controller 400 through the second air inlet openings 222 arranged at the top.

[0049] Therefore, the function of the second air inlet openings 222 changes when the heating fan 100 is stationary. In this case, air flows out of the heating fan 100, whereas during operation of the heating fan 100 it flows through the second air inlet openings 222 arranged at the top of the controller 400 into the device toward the second suction side 806.

[0050] Further, a guide wall 112 is arranged at the air channel 810 for at least partially separating the convection air flow to the controller 100 from air channel 810 when the heating fan 100 is stationary. The basis for this step consists in that the air channel 810 and the area of the heating block 300 are warm during operation of the heating fan 100 and this heat is given off as after-heat when the device is stationary. The controller is to be substantially spared from this after-heat. However, a certain proportion of after-heat serves to correctly switch off the heating fan and is advantageous for temperature control. Accordingly, the guide wall 112 is arranged between the air channel 810 and a front inner side 211 in the embodiment example. There is a small gap 113 between the guide wall 112 and the front inner side 211. The gap 113 advantageously serves to prevent vibrations from being transmitted from the air channel to the front 210 and deformation in the front 210 due to pressing out of the guide wall 112. The guide wall 112 substantially follows a side of the air channel 810. This one side of the air channel 810 is extended farther and terminates with a gap 113 relative to the forward front inner side 211.

[0051] The heating block 300 is thermally safeguarded by a safety temperature limiter 430 and sits on the heating block 300. Further, a fuse 431 is provided for additional security. The safety temperature limiter 430 has a lower shut-off temperature than the fuse 431. The safety temperature limiter 430 which is configured as PTC element responds first. After eliminating a possible error, the safety temperature limiter 430 resets and the heating fan 100 can be operated again. The fuse 431, which is provided with a higher shut-off temperature, responds when a temperature in the heating device exceeds the shut-off temperature of the safety temperature limiter 430. An additional thermal safeguarding of the heating fan 100 is achieved in this way. The heating block 300 is advantageously outfitted with a self-regulating heating element, particularly with self-regulating ceramic heating elements 301, which reduces the heating output with increasing temperature. Therefore, the heating block 300 in the embodiment example is inherently safe.

[0052] The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Although illustrative embodiments of the invention have been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope and spirit of the invention as defined by the appended claims.