Electric infrared heaters

Abstract

Electric infrared radiator, comprising a housing (1) provided with a reflector (2) or formed by a reflector, with an elongated, in particular rectangular, housing base (12) and two housing side walls (13) arranged on the longitudinal sides thereof, wherein in the housing (1) at least two U-shaped tubular heating elements (5) are held freely suspended by means of at least two holding plates (3) arranged at a distance from one another in the longitudinal direction thereof and are arranged at a distance from one another in parallel, which are detachably connected to a connection module for connection to an electrical power supply, characterized in that the at least two tubular heating elements (5) run longitudinally over the holding plates (3) along the housing base (12), in particular parallel to a housing side wall (13) and are arranged obliquely at an acute angle to the housing base (12).

Description

[0001] The invention relates to an electric infrared radiator, comprising a housing provided with a reflector or formed by a reflector, in which at least two U-shaped tubular heating elements are arranged parallel and spaced from one another, which are detachably connected to a connection module for connection to an electrical power supply.

[0002] Electric infrared heaters are particularly suitable for heating halls because they emit heat directly to people and objects instead of heating the air. They comprise a housing in which several rod-shaped tubular heaters are arranged parallel to one another, suspended freely above several retaining plates spaced apart from one another in the longitudinal direction. These usually comprise an outer casing made of transparent quartz glass, inside which a metallic heating conductor is arranged. To reduce lateral or rear radiation losses, the casing can be provided on its rear side with a reflective layer, for example made of metal such as aluminum or gold, or even zirconium dioxide. To concentrate and direct the infrared radiation, the housing includes a reflector. An electric infrared heater of this type is described, for example, in DE 1 733 904 A.

[0003] Electric infrared heaters of the previously known type are currently in use. These consist of tubular heaters operating at temperatures of 500°C to 800°C. To prevent the heating elements from overheating at these temperatures, the housing is equipped with ventilation openings for heat dissipation. However, these ventilation openings lead to a significant reduction in efficiency.

[0004] Electric infrared heaters are still in use today, which do not require ventilation openings in the housing. The rod-shaped heating elements are spaced further apart and operate at temperatures of up to 700°C, thus preventing heat buildup.

[0005] However, with these electric infrared heaters the power density is reduced, which in turn reduces the efficiency.

[0006] The invention aims to remedy this situation. The invention is based on the object of providing an electric infrared heater that has a high degree of efficiency and a high power density. According to the invention, this object is achieved by an electric infrared heater having the features of claim 1. Because the at least two tubular heating elements extend longitudinally over the retaining plates along the housing base (12), in particular parallel to a housing side wall and are inclined at an acute angle to the housing base, a high power density is achieved with simultaneously reduced heat buildup.

[0007] In the present case, a close positioning of a U-shaped tubular heater on the housing base means a pivoting of the tubular heater about its longitudinal central axis, whereby in plan view the upper leg of the tubular heater is located parallel and spaced from the lower leg.

[0008] Due to the oblique positioning of the U-shaped tubular heaters on the housing base, a large number of tubular heater legs are arranged on the surface, which are, however, arranged alternately on two levels at different distances from the housing base, a lower level with a smaller distance from the housing base and an upper level with a greater distance from the housing base.

[0009] In a further development of the invention, the tubular heaters are positioned at an angle of between 20° and 70°, preferably between 30° and 60°, and particularly preferably between 40° and 50° to the housing base. This ensures sufficient spacing between the tubular heaters.

[0010] In one embodiment of the invention, at least two of the at least two tubular heaters are positioned at an angle to each other in opposite directions on the housing base in a V-shape. Preferably, two groups of U-shaped tubular heaters arranged parallel to each other are positioned at an angle to each other in opposite directions on the housing base. This creates a larger space centrally between the two groups, thereby improving heat dissipation.

[0011] In a further embodiment of the invention, the retaining plates comprise several parallel retaining arms, each of which accommodates a tubular heater positioned at an angle to the housing base. This facilitates the precise installation of the tubular heaters on the retaining plates.

[0012] In a further development of the invention, the retaining plates have two V-shaped, angled, opposing retaining arms or retaining arm groups, each consisting of parallel first and second retaining arms. This enables a mirror-symmetrical arrangement of tubular heaters, further counteracting heat buildup. A V-shaped arrangement of two U-shaped tubular heaters achieves a large distance between the tubular heater legs arranged on the upper level.

[0013] In one embodiment of the invention, the retaining arms each have two spaced-apart, preferably L-shaped, receiving slots into which a leg of a tubular heater is inserted. This further facilitates the installation of the tubular heater. Furthermore, the receiving slots allow for simplified disassembly of a tubular heater that needs to be replaced.

[0014] In a further embodiment of the invention, the connection module has electrical contactors that can be used to switch the tubular heaters. This allows individual tubular heaters to be switched on, thus adjusting the heating power of the electric infrared heater.

[0015] In a further development of the invention, the reflector is made of aluminum-clad sheet steel, preferably with a highly reflective surface. This achieves a high degree of reflection compared to conventionally used aluminum reflectors, while simultaneously maintaining high dimensional stability at high temperatures. This metal layer composite, marketed under the registered trademark "Feran," combines the good forming and strength properties of steel with the physical properties of aluminum. Alternatively, the reflector can also be made of an aluminum alloy with a reflective surface.

[0016] In one embodiment of the invention, the housing has a connection compartment in which the connection module is arranged and which is delimited by a bulkhead, which preferably has curved openings for the connection contacts of the tubular heaters. This allows for interchangeable connection of the tubular heaters while simultaneously providing thermal insulation for the connection module.

[0017] In a further embodiment of the invention, a second bulkhead is arranged in the connection compartment at a distance from the first bulkhead. This second bulkhead is provided with holes for the connection contacts of the tubular heaters. This ensures alignment of the connection contacts for connection to the connection module located in the connection compartment. Furthermore, this creates a double bulkhead, increasing the insulation of the connection module from the tubular heaters.

[0018] In a further embodiment of the invention, the connection compartment is closed with a detachably attached cover. This ensures good accessibility to the connection module.

[0019] Further developments and refinements of the invention are specified in the remaining subclaims. Exemplary embodiments are illustrated in the drawings and described in detail below. They show: Fig. 1 the schematic spatial representation of an electric infrared heater; Fig. 2 the schematic representation of the electric infrared heater from Fig. 1 in plan view; Fig. 3 the detailed view of section A of the electric infrared heater from Fig. 2; Fig. 4 the detailed view of section B of the electric infrared heater from Fig. 2; Fig. 5 the electric infrared heater Fig. 1 in exploded view.

[0020] The electric infrared heater chosen as an exemplary embodiment essentially consists of a housing 1 with a reflector 2, on which retaining plates 3 are arranged at a distance from one another. A first bulkhead 41 is incorporated into the housing 1, defining a connection compartment 4 that accommodates a connection module (not shown).

[0021] The housing 1 is formed from an elongated casing sheet 11, which forms a substantially rectangular housing base 12 and two substantially rectangular housing side walls 13 extending obliquely outwards on its longitudinal sides, whereby a substantially trapezoidal cross-section is formed.

[0022] The reflector 2 is placed on the casing sheet 11 and, essentially corresponding to the casing sheet 11, is formed from an elongated reflector sheet 21 and, in the exemplary embodiment, is made of aluminum-plated steel sheet with a highly reflective surface. The reflector sheet 21 is shorter than the casing sheet 11 and also has a substantially rectangular reflector base 22, to whose long side walls reflector side walls 23 extend diagonally outwards. The reflector side walls 23 are bent twice, forming a first rectangular wall section 231 and a second wall section 232 angled inwards. Due to the two wall sections 231, 232 angled inwards to one another, the two reflector side walls have an inwardly curved shape.

[0023] At both ends, two head plates 14 are arranged parallel to the first bulkhead 41, connecting the two housing side walls 12 and the two reflector side walls 23, on the jacket plate 11 and the reflector plate 21. The reflector plate 21 of the reflector 2 rests against the first bulkhead 41. The housing side walls 13 are further provided with brackets 15 for attaching a protective grille (not shown).

[0024] The first bulkhead 41 is trapezoidal in shape, essentially corresponding to the cross-section of the casing sheet 11, and has arcuately angled, slot-like passages 42 for connection contacts 53 of the tubular heaters 5. On its side facing the receiving space 4, a second bulkhead 43 is placed against the first bulkhead 41, forming a double bulkhead. The second bulkhead 43 is provided with holes 44, each of which is aligned with a curved end of a passage 42 of the first bulkhead 41. The holes 44, in turn, are each aligned with a connection contact of the connection module (not shown) arranged in the connection space 4. The connection space 4 is closed by a detachable cover 45. To ventilate the connection module (not shown) arranged in the connection space 4, the cover 45 is provided with ventilation slots 46.

[0025] The holding plates 3 also have a trapezoidal outer contour and comprise a base-side frame plate 31, to which three first holding arms 32 are angled, parallel to one reflector side wall 23, and three second holding arms 33 are angled, parallel to the other, opposite reflector side wall 23. The oblique outer edges of the trapezoidal outer contour of the holding plates 3 are each formed by the outer, angled first holding arm 32 and the outer, angled second holding arm 33. Each of these two outer holding arms 32, 33 forms a holding arm group with two further holding arms 32, 33 arranged at a distance from these, the inner holding arms 32, 33 of which are angled in a V-shape relative to one another.

[0026] On their inwardly directed longitudinal sides, the holding arms 32, 33 are each provided with two spaced-apart, largely L-shaped receiving slots 34. On its underside opposite the holding arms 32, 33, the frame plate 31 has angled clamping webs 35. The holding plates 3 are fastened to the housing base 12 by the reflector plate 21 via the clamping webs 35. For this purpose, the casing plate 11 has insertion tabs 111 that are guided through recesses 21 in the reflector 2 and which receive the clamping webs 35. The reflector plate 21 of the reflector 2 is connected to the casing plate 11 via the clamping webs 35, which engage in the insertion tabs 111.

[0027] The tubular heaters 5 are U-shaped, with two legs 51, 52, which are provided with an electrical connection contact 53 at their free ends. The tubular heaters 5 are each inserted with their two legs 51, 52 into one of the two receiving slots 33 of one of the holding arms 32, 33 of the holding plates 3, which are arranged parallel and spaced from one another. The three tubular heaters 5 inserted into the receiving slots 33 of the first holding arms 32 are angled, parallel to one another, and parallel to a reflector side wall 23. The three tubular heaters 5 inserted into the receiving slots 33 of the second holding arms 32 are angled, parallel to one another, and parallel to the other, opposite reflector side wall 23. This forms two V-shaped groups of tubular heaters 5 arranged parallel to one another.

[0028] When "screwing in" the two legs 51, 52 of a respective tubular heater 5 along two spaced-apart L-shaped receiving slots 33, its connection contacts 53 are guided along the arcuately angled passage 42 of the first bulkhead 41 until it finally slides through a bore 44 of the second bulkhead 43 aligned with the respective passage 42, where it is contacted by the connection module (not shown) arranged within the connection compartment 4. Fig. 3 and Fig. Figure 4 shows the fastening of the U-shaped tubular heaters 5. Here, all first legs 51 of the tubular heaters 5 are arranged on a lower level, and all second legs 52 of the tubular heaters 5 are arranged on an upper level spaced apart from the lower level. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 1 733 904 A

[0002]

Claims

[1] Electric infrared radiator, comprising a housing (1) provided with a reflector (2) or formed by a reflector, with an elongated, in particular rectangular, housing base (12) and two housing side walls (13) arranged on its longitudinal sides, wherein in the housing (1) at least two U-shaped tubular heating elements (5) are held freely suspended by means of at least two retaining plates (3) arranged at a distance from one another in their longitudinal direction and are arranged parallel and spaced from one another, which are detachably connected to a connection module for connection to an electrical power supply, characterized by that the at least two tubular heating elements (5) are arranged longitudinally over the retaining plates (3) along the housing base (12), in particular parallel to a housing side wall (13) and are arranged obliquely at an acute angle to the housing base (12). [2] Electric infrared heater according to claim 1, characterized bythat the tubular heating elements (5) are set at an angle of between 20° and 70°, preferably between 30° and 60°, particularly preferably between 40 and 50° to the housing base (12). [3] Electric infrared heater according to claim 1 or 2, characterized by that at least two of the at least two tubular heating elements (5) are arranged in a V-shape relative to one another in opposite directions at an angle to the housing base (13). [4] Electric infrared heater according to one of the preceding claims, characterized by that the holding plates (3) have a plurality of holding arms (32, 33) arranged parallel to one another, each of which receives a tubular heating element (5) positioned at an angle to the housing base (12). [5] Electric infrared heater according to one of the preceding claims, characterized bythat the holding plates (3) have two V-shaped holding arms (32, 33) or holding arm groups, each consisting of holding arms (32, 33) arranged parallel to one another. [6] Electric infrared heater according to claim 4 or 5, characterized by that the holding arms (32, 33) each have two spaced-apart, preferably L-shaped receiving slots (33) into which a leg (51, 52) of a received tubular heating element (5) is inserted. [7] Electric infrared heater according to one of the preceding claims, characterized by that the connection module has electrical contactors via which the tubular heating elements (5) can be switched. [8] Electric infrared radiator according to one of the preceding claims, characterized bythat the reflector (2) is made of aluminum-plated steel sheet with preferably a highly reflective surface or of an aluminum alloy with a reflective surface. [9] Electric infrared heater according to one of the preceding claims, characterized by that the housing (1) has a connection space (4) in which the connection module is arranged and which is delimited by a first bulkhead (41) which preferably has arcuately angled bushings (42) for connection contacts (53) of the tubular heating elements (5). [10] Electric infrared heater according to claim 9, characterized by that in the connection space (4) a second bulkhead (43) is arranged at a distance from the first bulkhead (41), which second bulkhead is provided with bores (44) for the passage of the connection contacts (53) of the tubular heating elements (5). [11] Electric infrared heater according to claim 9 or 10, characterized bythat the connection compartment (4) is closed by a detachably attached cover (45).

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