GB2369424A - Tumble dryer - Google Patents

Abstract

A vented tumble dryer which draws air in through an inlet 9 along the direction of arrow A, heats it and propels it in region 7 through the drum of the tumble dryer in the direction of arrow B, and allows it to escape through outlet 10 in the direction of arrow C has flaps 11 and 12 which may optionally block the inlet and outlet to set up a re-circulation path in the direction of dotted arrow D in order to operate the dryer first in a re-circulation mode and then in a vented mode.

Description

TUMBLE DRYER

This invention relates to tumble dryers, especially vented tumble dryers.

A tumble dryer gently tumbles wet clothes in a current of warm air usually after they have been spun in a washing machine. Moisture is evaporated until the clothes are dry.

The air entering the inlet of the tumble dryer is drawn from the room in which the tumble dryer is located, and the moist air after it has passed over the clothes emerges from an outlet in the tumble dryer. The outlet could feed into the room containing the tumble dryer if well ventilated, or the moist air can be ducted directly to the outside.

The stream of warm air is produced by means of a fan and a heater, the output of which stays constant over the period of operation of the tumble dryer.

Heat transfer, however, is relatively inefficient in the early stages of the drying process because the lower vapour content of the air surrounding the load naturally reduces the amount of water vapour which is swept into the warm air stream.

The invention provides a vented tumble dryer including means optionally to re-circulate the air.

This permits the warm air to be re-circulated in the early stages of the drying process.

The means optionally to re-circulate the air may include hinging flaps.

One way of carrying out the invention will now be described in detail, by way of example, with reference to the accompanying drawing, which is an axial section of the tumble dryer of the invention.

Referring to the drawing, the tumble dryer consists of a drum 1 which is rotatable about a horizontal axis 2 by means of a motor (not shown). The drum has an opening 3 at its front end and a perforated area 4 at its rear end. The cabinet 5 in which the drum is mounted is closed at the front by a door 6 which partly closes the opening 3 in the front of the drum. However, sufficient gap is left around the periphery of the door 6 to allow warm air to pass freely through the perforated region 4 and out through the opening 3.

The air is heated by means of a heater (not shown) in a space 7 in the cavity, which also houses a fan 8. Air is drawn in through inlet 9, and passes along the paths defined by the arrows A, B, C.

As thus described, the tumble dryer operates in a conventional vented mode. The air intake A may draw air from the room in which the tumble dryer is sited, and it may discharge it through outlet 10 into the same room, or outlet 10 may be coupled to a duct to vent the moist air where desired. In operation, the moist load is dried by operating the heater and fan to set up the vented flow along the arrows A, B, C.

In accordance with the invention, hinged flaps 11 and 12 are pivotable to produce an optional re-circulation mode.

Thus, flap 11 normally closes off aperture 13 in internal panel 14, and flap 12 normally closes off aperture 15 in internal panel 16.

In accordance with the invention, in the first (warm-up) phase of the drying process, the flap 11 is pivoted (to the dotted position) to close off duct 17 which leads to outlet 10.

Duct 17 is cylindrical but has an oblique end surface to engage with the flap 11.

Similarly, flap 12 is pivoted (to the dotted position) to block duct 18 which communicates with inlet 9. Duct 18 is also a cylindrical tube cut off obliquely in order to engage with flap 12.

Thus, the flaps 11 and 12 are optionally pivotable to close the inlet and the outlet 10, thereby setting up a re-circulation flow path which now includes the arrow B and the dotted arrow D. When the load has been heated sufficiently, the warm-up phase is succeeded by a drying phase. Thus, the flaps 11 and 12 revert to the full line position shown in the drawing, so that normal vented flow takes place. In these conditions, the pick-up of moisture from the clothes is far quicker, and there is an overall saving in the time the dryer takes to dry a load.

The flaps are controlled automatically during the drying operation. However, they could be operated manually if desired.

Although the invention has been described in relation to a tumble dryer, the invention is also applicable to a washer dryer. Also, while the direction of flow of the wann air has

been described as being diverted by hinging flaps, other methods of diverting the warm been descnueu air flow may be adopted.

Claims (5)

1. CLAIMS 1. A vented tumble dryer including means optionally to re-circulate the air.
2. 2. A tumble dryer as claimed in Claim 1, including hinging flaps to re-circulate the

   air.
3. 3. A tumble dryer as claimed in Claim 2, in which the hinging flaps open and close inlets and outlets for the air flow through the dryer.
4. 4. A tumble dryer as claimed in any one of Claims 1 to 3, in which a drying operation is arranged to consist of a first period of re-circulation followed by a second period of vented flow.
5. 5. A vented tumble dryer substantially as herein described with reference to the accompanying drawings.