GB2123538A

GB2123538A - A heating means for a drier for drying washing

Info

Publication number: GB2123538A
Application number: GB08314194A
Authority: GB
Inventors: Friedhelm Varnholt; Gerhard Rodefeld; Hans Fey
Original assignee: Miele und Cie KG
Current assignee: Miele und Cie KG
Priority date: 1982-05-21
Filing date: 1983-05-23
Publication date: 1984-02-01
Also published as: DE3219067C2; GB2123538B; DE3219067A1; GB8314194D0

Abstract

The heating means comprises a heater housing (2) and a cover housing (3), the heater housing (2) accommodating the heating unit (1), and the cover housing (3) encasing the heater housing (2). This arrangement permits air flow channels (4) to be formed between the cover housing (3) and the heater housing (2), whereby a secondary air stream (14) may be produced which flows in a direction opposite the direction of the main air flow (13) during operation of the drier. This secondary air stream (14) causes the radiation losses of the heating means to be reduced, thereby permitting considerably improved efficiency to be achieved. The cover housing (3) and the heater housing (2) may each be comprised of symmetrically shaped half-shells of sheet metal. Stamped indentations (6 and 7) provided in the heater housing (2) and in the cover housing (3) form spacer supports between the two housing members and simultaneously serve as spot- welding locations for the housing members to be securely interconnected. <IMAGE>

Description

SPECIFICATION A heating means for a drier for drying washing The invention relates to a heating means for a drier for drying washing or for a washing drier, more especially for a drying apparatus of the drum-type construction in accordance with the principle of exhaust air.

The heating means for heating the process air in a drier for drying washing in accordance with the drum principle is often accommodated in the rear air channel of the drier. In such a case, the air conducting channel simultaneously forms the heater housing for the heating unit (US PS 3,670,143). A disadvantage of such arrangements can be seen to reside in the fact that, during the drying operation, there is considerable energy loss due to thermal radiation in this region, and moreover, the intensive radiation heat of the heating means may harm delicate fabric items in the drum, and the invention seeks to provide a remedy therefor.

According to the present invention there is provided a heating means for a drier for drying washing or for a washing drier, more especially but not exclusively for drying apparatus of the drum-type construction in accordance with the principle of exhaust air, wherein a heater unit is accommodated in a heater housing in order to heat the drying air, and the heater housing is encased in a cover housing such that air flow channels are formed between the heater housing and the cover housing.

Thus, by such an arrangement, radiation losses are kept as small as possible, so that efficiency is improved and the heating means can no longer harm delicate items of washing in the drum.

In addition to improving efficiency, the invention also achieves a further advantage in that the heating means is a compact unit which can be disposed in the drier so as to be easily accessible for servicing and assembly purposes.

The invention will be described more fully, by way of example, with reference to the accompanying drawings, in which:~ Fig. 1 is a sectional view, taken from the side, of a heating means for a drier for drying washing in accordance with the principle of exhaust air; and Fig. 2 illustrates the heating means of Fig. 1, viewed in the direction of the air flow.

Fig. 1 illustrates a heating device which, in the case of a drier for drying washing, seeks to heat the process air and is disposed in the flow path of the drier for drying washing. The heater unit 1 comprises a plurality of heating coils and is secured in a heater housing 2. The heater housing 2 is encased in a cover housing 3, such that air flow channels 4 are formed between the heater housing 2 and the cover housing 3.

The heater housing 2 and the cover housing 3 are preferably comprised of symmetrically-shaped half-shells of sheet metal. In such a case, interengaging guide projection members 5 are provided in the overlapping region of the sheet metal half-shells in order to secure and aid assembly of the housing halves. To provide spacer supports between each of the two housing members, stamped indentations 6 and 7 are made in the heater housing 2 and in the cover housing 3.

The regions of the stamped indentations 6 and 7 simultaneously serve as spot-welding locations for the mutual connection of the two housing members.

The heater housing 2 is boxed inside the cover housing 3 in an offset manner, whereby the cover housing 3 protrudes at the air inlet end E of the heating means, while the heater housing 2 is extended at the air outlet end A. At its air outlet end A, the heater housing 2 is provided with a moulded-on connection pipe 8 which permits the heater housing 2 to be connected to the air conducting path of the drier for drying washing. By means of resilient projection members 9 which are provided in the connection pipe 8, the heating means can be mounted upon an appropriate connection-piece in a clamping manner.

For the insertion of thermostat gauges, through-bores 10 are punched in the heater housing 2 and cover housing 3. Furthermore, a through-aperture 11 is provided in the cover housing 3 for the insertion of appropriate electrical leads. In order to secure the heating means in the drying machine, securing flanges 12 are provided on the cover housing 3. In order to reduce the overall height of the heating means, such heating means is of a flattened construction in its upper and lower regions.

Inwardly extending channels 15 are additionally provided in the flattened regions.

The mode of operation of the heating means is described hereinafter during operation of the drier for drying washing: A low pressure region is produced in the air outlet region (A) of the heating means by means of the fan of the drier for drying washing. Cold air is thus drawn into the heating means from the assembly chamber of the drier at the air inlet end (E). This main air stream is indicated by the arrows 13. Moreover, however, a secondary air stream is also produced as illustrated by the arrows 14. This secondary air stream 14 is conducted into the air flow channels 4 between the cover housing 3 and heater housing 2 in a direction opposite to the flow direction of the main air stream 1 3, and the secondary air stream 14 is combined with the main air stream at the air inlet end (E) of the heating means. Because of this special arrangement of the heating means, the energy which would otherwise be lost as radiation heat is largely recovered and re-supplied to the air stream of the drier. In order to further intensify the effect of the secondary air stream, it would be conceivable to reduce the cross-section at the air inlet end (E) of the heating means.

1. A heating means for a drier for drying washing or for a washing drier, more especially but not exclusively for drying apparatus of the drum-type construction in accordance with the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION A heating means for a drier for drying washing The invention relates to a heating means for a drier for drying washing or for a washing drier, more especially for a drying apparatus of the drum-type construction in accordance with the principle of exhaust air. The heating means for heating the process air in a drier for drying washing in accordance with the drum principle is often accommodated in the rear air channel of the drier. In such a case, the air conducting channel simultaneously forms the heater housing for the heating unit (US PS 3,670,143). A disadvantage of such arrangements can be seen to reside in the fact that, during the drying operation, there is considerable energy loss due to thermal radiation in this region, and moreover, the intensive radiation heat of the heating means may harm delicate fabric items in the drum, and the invention seeks to provide a remedy therefor. According to the present invention there is provided a heating means for a drier for drying washing or for a washing drier, more especially but not exclusively for drying apparatus of the drum-type construction in accordance with the principle of exhaust air, wherein a heater unit is accommodated in a heater housing in order to heat the drying air, and the heater housing is encased in a cover housing such that air flow channels are formed between the heater housing and the cover housing. Thus, by such an arrangement, radiation losses are kept as small as possible, so that efficiency is improved and the heating means can no longer harm delicate items of washing in the drum. In addition to improving efficiency, the invention also achieves a further advantage in that the heating means is a compact unit which can be disposed in the drier so as to be easily accessible for servicing and assembly purposes. The invention will be described more fully, by way of example, with reference to the accompanying drawings, in which:~ Fig. 1 is a sectional view, taken from the side, of a heating means for a drier for drying washing in accordance with the principle of exhaust air; and Fig. 2 illustrates the heating means of Fig. 1, viewed in the direction of the air flow. Fig. 1 illustrates a heating device which, in the case of a drier for drying washing, seeks to heat the process air and is disposed in the flow path of the drier for drying washing. The heater unit 1 comprises a plurality of heating coils and is secured in a heater housing 2. The heater housing 2 is encased in a cover housing 3, such that air flow channels 4 are formed between the heater housing 2 and the cover housing 3. The heater housing 2 and the cover housing 3 are preferably comprised of symmetrically-shaped half-shells of sheet metal. In such a case, interengaging guide projection members 5 are provided in the overlapping region of the sheet metal half-shells in order to secure and aid assembly of the housing halves. To provide spacer supports between each of the two housing members, stamped indentations 6 and 7 are made in the heater housing 2 and in the cover housing 3. The regions of the stamped indentations 6 and 7 simultaneously serve as spot-welding locations for the mutual connection of the two housing members. The heater housing 2 is boxed inside the cover housing 3 in an offset manner, whereby the cover housing 3 protrudes at the air inlet end E of the heating means, while the heater housing 2 is extended at the air outlet end A. At its air outlet end A, the heater housing 2 is provided with a moulded-on connection pipe 8 which permits the heater housing 2 to be connected to the air conducting path of the drier for drying washing. By means of resilient projection members 9 which are provided in the connection pipe 8, the heating means can be mounted upon an appropriate connection-piece in a clamping manner. For the insertion of thermostat gauges, through-bores 10 are punched in the heater housing 2 and cover housing 3. Furthermore, a through-aperture 11 is provided in the cover housing 3 for the insertion of appropriate electrical leads. In order to secure the heating means in the drying machine, securing flanges 12 are provided on the cover housing 3. In order to reduce the overall height of the heating means, such heating means is of a flattened construction in its upper and lower regions. Inwardly extending channels 15 are additionally provided in the flattened regions. The mode of operation of the heating means is described hereinafter during operation of the drier for drying washing: A low pressure region is produced in the air outlet region (A) of the heating means by means of the fan of the drier for drying washing. Cold air is thus drawn into the heating means from the assembly chamber of the drier at the air inlet end (E). This main air stream is indicated by the arrows 13. Moreover, however, a secondary air stream is also produced as illustrated by the arrows 14. This secondary air stream 14 is conducted into the air flow channels 4 between the cover housing 3 and heater housing 2 in a direction opposite to the flow direction of the main air stream 1 3, and the secondary air stream 14 is combined with the main air stream at the air inlet end (E) of the heating means.Because of this special arrangement of the heating means, the energy which would otherwise be lost as radiation heat is largely recovered and re-supplied to the air stream of the drier. In order to further intensify the effect of the secondary air stream, it would be conceivable to reduce the cross-section at the air inlet end (E) of the heating means. CLAIMS

1. A heating means for a drier for drying washing or for a washing drier, more especially but not exclusively for drying apparatus of the drum-type construction in accordance with the principle of exhaust air, wherein a heater unit (1) is accommodated in a heater housing (2) in order to heat the drying air, and the heater housing (2) is encased in a cover housing (3) such that air flow channels (4) are formed between the heater housing (2) and the cover housing (3).

2. A heating means as claimed in claim 1 , in which the heater housing (2) is boxed inside the cover housing (3) in an offset manner, so that the cover housing (3) protrudes at the air inlet end (E) relative to the heater unit (1), while the heater housing (2) is extended at the air outlet end (A) of the heating means (1).

3. A heating means as claimed in claims 1 and 2, in which the heater housing (2) is provided with a moulded-on connection pipe (8) at the air outlet end (A).

4. A heating means as claimed in claims 1 and 2, in which the heater housing (2) and/or the cover housing (3) are/is comprised of symmetrically shaped half-shells of sheet metal.

5. A heating means as claimed in claim 4, in which interengaging guide projection members (5) are provided in the overlapping region of the sheet metal half-shells in order to secure the two housing halves.

6. A heating means as claimed in claims 1 and 2, in which the heating housing (2) and the cover housing (3) have stamped indentations (6, 7) formed therein, such stamped indentations (6, 7) being capable of acting as spacer supports between the two housing members and simultaneously being capable of serving as spotwelding locations.

7. A heating means as claimed in claim 3, in which resilient projection members (9) are provided in the connection pipe (8) and are disposed in the connection region relative to the air channel of the drier.

8. A heating means as claimed in claims 1 and 2, in which through-bores (10) are punched in the heater housing and cover housing for the insertion of thermostat gauges.

9. A heating means as claimed in claims 1 and 2, in which a through-aperture (11) is provided in the cover housing (3) for the insertion of electrical connecting leads.

10. A heating means as claimed in claims 1 and 2, in which the housing members (2, 3) are of a flattened construction in their lower and upper regions.

11. A heating means as claimed in claims 1, 2 and 10, in which channels (1 5) are provided in the upper and lower regions.

12. A heating means substantially as herein described with reference to and as illustrated in the accompanying drawings.