GB2219652A

GB2219652A - Water-rinsed lint filter

Info

Publication number: GB2219652A
Application number: GB8813741A
Authority: GB
Inventors: Peter Richard Powell; Brian James Batt
Original assignee: SERVIS GROUP Ltd
Current assignee: SERVIS GROUP Ltd
Priority date: 1988-06-10
Filing date: 1988-06-10
Publication date: 1989-12-13
Also published as: GB8813741D0

Abstract

In a washer-drier, a screen (28) is so positioned where an air flow path and a water drain path from the drum diverge that fibres carried from the drum by the air flow during tumble drying are retained on the screen and are subsequently washed from the screen when water is drained from the drum. <IMAGE>

Description

Title: "Washer-Drier and Method of Operating same" Description of Invention The present invention relates to a washer-drier, by which we mean a machine suitable for washing and drying clothes and other textile articles and which has a drum in which the articles are contained during washing and drying. Drying of the articles is achieved in a washer-drier by passing heated air into the drum and circulating the heated air from the drum through an air cooler and then through an air heater back to the drum.

Moisture evaporates into the air from the articles in the drum and condenses when the air stream is cooled in the air cooler. To promote evaporation of moisture from the articles into the airstream, the articles are moved during drying by turning of the drum. This movement promotes separation of fibres from the articles and these are carried from the drum by the airstream.

If the fibres are carried as far as the air heater, there is a risk of fibres coming into contact with electrical heating elements in the air heater and being heated to a temperature at which the fibres become degraded or even burn.

Combustion of the fibres within the washer-drier results in smells which may be alarming to persons in the vicinity of the machine and may give rise to a dangerous situation. Even thermal degradation of the fibres without combustion is likely to alarm persons in the vicinity of the machine, owing to the smells which are produced.

According to a first aspect of the present invention, there is provided a method of operating a washer-drier wherein articles to be washed are placed in a drum in a chamber, water is admitted to the chamber, the drum is moved to agitate the articles in the water, the water is withdrawn from the chamber along a drainage path, the drum is rotated to expel water from the articles, air is then circulated around a substantially closed path from the chamber through a screen and a cooler to a heater and from the heater into the chamber, fibres carried from the chamber by the air are collected on the screen and the screen is subsequently washed by water, without removal of the screen from the machine.

Circulation of the air through the screen upstream of the air heater reduces or eliminates the risk of a significant quantity of fibres reaching the air heater. Washing of the screen by water without removal of the screen from the machine avoids an excessive accumulation of fibres on the screen, such as would seriously inhibit the circulation of air during drying, without the inconvenience of gaining access to a screen, removing the screen from the machine and cleaning the screen before replacing the screen.

In the preferred method, the air leaves the chamber along the drainage path and diverges from the drainage path at a position downstream of the chamber, the air passing through the screen at that position and continuing along a branch path. When water is subsequently withdrawn from the chamber along the drainage path, the water will pass into contact with the screen and automatically wash the screen. Such washing of the screen may be effected by carrying out a rinse cycle after the washed articles have been dried and removed from the drum or may be effected during a washing cycle performed on a further batch of articles.

According to a second aspect of the invention, there is provided a washer/drier comprising means defining a chamber, a drum for receiving articles to be washed and dried, the drum being mounted for rotation in the chamber, drive means for turning the drum, an air cooler, an air heater, ducts providing a delivery path for the delivery of water to the chamber, a drain path for the discharge of water from the chamber and a flow path for the circulation of air from the chamber through the cooler and the heater, a fan for impelling air along the flow path and a screen disposed in the flow path at a position downstream from the chamber but upstream from the air heater, wherein the ducts provide for flow of water past the screen for washing the screen.

The screen preferably lies below the level of the drum. In this position, the screen will be submerged in water when water is admitted to the drum.

The drain path preferably leads from the chamber past the the screen. With this arrangement, the discharge of water from the chamber along the drain path will automatically wash the screen.

An example of a washer-drier embodying the second aspect of the invention and which is used in a method according to the first aspect of the invention will now be described, with reference to the accompanying drawings, wherein: FIGURE I shows a diagrammatic representation of certain parts of the washer-drier; FIGURE 2 shows some of the parts of Figure I in side elevation and partly in cross-section in a vertical plane; and FIGURE 3 shows a screen as viewed in the direction of the arrow Ill in Figure 2.

The machine illustrated in the accompanying drawings includes a structure defining a generally cylindrical chamber 10 disposed with its axis substantially horizontal and having at one of its ends a door (not shown). A perforate, cylindrical drum II is disposed inside the chamber 10 in coaxial relation therewith and is supported by suitable bearings (not shown) at the end of the drum remote from the door for rotation about the axis of the drum. Outside the chamber 10, there is provided an electric motor (not shown) for rotating the drum relative to the wall of the chamber 10.

Electrically energisable elements may be provided in the chamber 10 for heating water in the chamber and an electrically operated valve 12 is provided for controlling the admission of water to the chamber via an inlet hose 13.

The structure and arrangement of the parts thus far described is well known and therefore will not be described in detail.

A drainage duct 14 communicates with the chamber 10 at the bottom of the chamber and leads downwardly therefrom and around a bend 15 to a horizontal duct 16 which lies below the chamber 10. At its end remote from the bend 15, the duct 16 communicates with a lower end portion of an air cooler 17. The air cooler extends upwardly from the duct 16 behind the chamber 10 and drum II to an electrically energisable fan 18. Immediately adjacent to an upper part of the chamber 10, there is an air heater 19 in the form of a hollow housing containing an electrically energisable heating element 20.

The interior of the air heater communicates with the interior of the chamber 10 adjacent to the end thereof at which the door is provided. An end of the air heater housing remote from the door to the chamber 10 communicates with the interior of a housing of the fan 18. The ducts 14 and 16, the air cooler 17, the fan 18 and the air heater 19 collectively define a flow path for the circulation of air from the chamber 10 through the air cooler and the air heater back to the chamber.

The air cooler 17 may comprise an elongated, hollow housing and a nozzle 21 for directing a spray of cold water along the housing. Cold water can be directed to the nozzle 21 along a hose 22 by the valve 12. There is provided a drain 23 from the bottom of the fan housing to the air cooler, to drain from the fan any water which is carried into the fan from the air cooler.

There is disposed below the horizontal duct 16 #an electrically operated water pump 24 for drawing water from the chamber 10. A water outlet 25 leads from the pump to a waste pipe or other suitable disposal point for water. The pump communicates with the duct 16 via a vertical duct 26 and a horizontal pump inlet duct 27 which branches off from the vertical duct.

An upper end of the vertical duct opens into the horizontal duct 16 immediately adjacent to the bend 15 and at a lower part of the boundary wall of the duct 16. The drainage duct 14, vertical duct 26 and pump 24 collectively define a drain path along which water can be discharged from the chamber 10. It will be seen that the drain path branches off from the air flow path at the junction of the horizontal duct 16 with the vertical duct 26.

Upstream of this junction, a single path defined by the drain duct 14 constitutes a part of the water drain path and a part of the air flow path.

At the position where the water drain path branches off from the air flow path, there is provided a screen 28. In the example illustrated, the screen is a substantially flat structure comprising a frame 29 and a number of elongated, rectilinear elements 30 spanning the frame. These elements are spaced apart and are mutually parallel. The elements collectively occupy less than one half of the space enclosed by the frame 29, the gaps between the elements representing a major part of the area occupied by the screen.

Each of these gaps extends without interruption from the frame at one margin of the screen to the frame at an opposite margin of the screen.

The screen is disposed with the lengths of the elements 30 inclined at an acute angle to a longitudinal axis of the horizontal duct 16 and inclined at an acute angle to a longitudinal axis of the vertical duct 26. The frame 29 is in contact with or conforms closely to the shape of the internal surface of the wall of the duct 16 and, since this duct is cylindrical, the frame is elliptical.

The screen is disposed with a part of the frame 29 spanning the open upper end of the vertical duct 26 so that, adjacent to one face of the screen, there is a substantially unimpeded passage between the bend 15 and the vertical duct and that there is, adjacent to an opposite end of the screen, a substantially unimpeded passage between the vertical duct and that part of the horizontal duct 16 which extends to the air cooler 17. The second of these passages is substantially smaller than is the first of these passages.

The screen is retained in this position by a pair of legs 31 which extend from the frame 29 a short distance along the interior of the vertical duct 26 and by a flange 32 protruding from the frame 29 at a position remote from the legs 31, the flange engaging with a seat provided at the wall of the duct 16 where there is a change in the cross-section of this duct at a joint between a component which defines the bend 15 and a component which defines the remainder of the duct 16.

The frame 29, elements 30, legs 31 and flange 32 of the screen may be formed as an integral moulding of a plastics material. Alternatively, separately formed elements 30, for example lengths of wire, may be connected with the frame. Each of the elements 30 is preferably of uniform transverse cross-section throughout its length and presents a smooth surface over which air can flow easily and along which fibres can slide, during washing of the screen. It will be noted that each of the elements 30 is arranged with its length extending in a direction from an upper part of the wall of the duct 16 towards the vertical duct 26. This is generally the same as the direction along which water flows past the screen from the chamber 10 to the pump 24.

The gaps between adjacent elements 30 of the screen preferably have the same width and this width is preferably within the range 2mm to 5mm and more preferably within the range 3mm to 4mm. The number of elements 30 is preferably within the range 5 to 20 and more preferably within the range 9to 13.

The screen 28 has sufficient resilient flexibility to permit insertion of the screen into the component which defines the duct 16 from the end thereof which is adjacent to the bend 15, prior to assembly of that component with the further component which defines the bend.

The angle included between a plane which touches the frame 29 at one face of the screen and the axis of the horizontal duct 16 is within the range 400 to 700 and is more preferably within the range 450 to 650.

Articles which are to be washed and dried are placed in the drum 11 through the doorway of the chamber 10, whilst there is no water in the chamber. Water is then admitted by the valve 12 to the chamber 10. Some of the water admitted flows from the chamber through the drain duct T4 and occupies the horizontal duct 16 and a lower part of the air cooler 17. Water may be admitted until the level thereof is near to the axis of rotation of the drum. Washing powder may be entrained in the admitted water in a known manner. Alternatively, the washing powder may be placed in the drum II with the articles to be washed.

The drum I l is turned to wash the articles and the pump 24 is then operated to withdraw the water from the chamber 10 along the drain path.

Water leaving the chamber 10 through the drain duct 14 enters the vertical duct 26 across the face of the screen 28 and thus washes the screen. Water also enters the vertical duct 26 from the horizontal duct 16 and the air cooler 17. Further quantities of water may be admitted to and drained from the chamber 10 to rinse the articles. The drum II is then rotated at a relatively high speed to expel water from the articles by centrifugal action. The drying cycle is then commenced.

During the drying cycle, air is heated by the heating element 20 and driven by the fan 18 into the chamber 10 where the drum 11 is turned to move the articles and establish contact between all parts of the articles and the heated air. Heating of the articles by the air promotes evaporation of water from the articles and the water vapour thus produced flows with the air from the chamber 10 through the drain duct 14, the screen 28 and the horizontal duct 16 to the air cooler 17. Cold water is admitted to the air cooler, being sprayed into the air therein and/or trickling down the internal surfaces of the walls of the air cooler, so that the temperature of the moist air from the chamber 10 is reduced. Some of the water vapour carried from the chamber 10 by the air is condensed in the air cooler 17.This condensate, together with water admitted to the air cooler, drains from the air cooler along the horizontal duct 16 into the vertical duct 26, passing outside the frame 29. The air is drawn from the air cooler by the fan 18 and is driven through the air heater 19 back to the chamber 10.

In many cases, fibres will be carried from the articles in the drum during drying of those articles. The fibres will be carried by the air stream through the drain duct 14 to the screen 28 but will be retained by the screen.

Fibres will accumulate on the screen and in the duct leading to the screen.

After the articles have been dried, they are removed from the drum II.

With the drum empty, there may be carried out a further rinse cycle (or a further wash cycle), during which water is admitted to the chamber 10 and then withdrawn from the chamber by the pump 24. -This causes water to flow past the screen 28 from the bend 15 to the vertical duct 26. Fibres are washed from the duct adjacent to the screen and from the screen and are carried by the water to the pump and away from the machine through the outlet 25.

The features disclosed in the foregoing description, or the accompanying drawing, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method for attaining the disclosed result, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS:

I. A method of operating a washer-drier wherein articles to be washed are placed in a drum in a chamber, water is admitted to the chamber, the drum is moved to agitate the articles in the water, the water is withdrawn from the chamber along a drain path, the drum is rotated to expel water from the articles, air is then circulated around a substantially closed path from the chamber through a screen and a cooler to a heater and from the heater into the chamber, fibres carried from the chamber by the air are collected on the screen and wherein the screen is subsequently washed by water.
2. A method according to Claim I wherein air leaves the chamber along the drain path and diverges from the drain path at a position downstream of the chamber and wherein the air passes through the screen at said position and continues along a branch path.
3. A method according to Claim 2 wherein, during washing of the screen, water flows along the drain path in contact with the screen.
4. A method according to Claim 3 wherein, during washing of the screen, water flows towards the screen along both the branch path and a first portion of the drain path and water flows away from the screen along a second portion of the drain path.
5. A method according to any preceding claim wherein the screen is washed prior to drying of further articles in the drum.
6. A washer/drier comprising means defining a chamber, a drum for receiving articles to be washed and dried, the drum being mounted for rotation in the chamber, drive means for turning the drum, an air cooler, an air heater, ducts providing a delivery path for the delivery of water to the chamber, a drain path for the discharge of water from the chamber and a flow path for the circulation of air from the chamber through the cooler and the heater, a fan for impelling air along the flow path and a screen disposed in the flow path at a position downstream from the chamber but upstream from the air heater, wherein the ducts provide for flow of water past the screen for washing the screen.
7. A washer-drier according to Claim 6 wherein the drum is mounted for rotation about a substantially horizontal axis and the screen lies below the level of the axis.
8. A washer-drier according to Claim 7 wherein the screen is mounted below the level of the drum.
9. A washer-drier according to any one of Claims 6 to 8 wherein the drain path leads from the chamber past the screen.
10. A washer-drier according to Claim 9 wherein said ducts include a first duct leading from the chamber towards the screen, a second duct leading from the screen to a water outlet and a third duct leading from the screen to the air cooler.
II. A washer-drier according to Claim 10 wherein a margin of the screen spans an end of the third duct to provide direct communication past the screen between the first and third ducts and between the second and third ducts.
12. A washer-drier according to any one of Claims 9 to 11 wherein the screen is substantially flat and is inclined to the general direction of the drain path up to the screen.
13. A washer-drier according to any one of Claims 6 to 12 wherein the screen comprises a plurality of elongated elements arranged side-by-side with gaps between adjacent elements extending without substantial interruption across a major part of the screen.
14. A washer-drier according to Claim 13 wherein said elements are rectilinear.
15. A washer-drier according to Claim 13 or Claim 14 wherein the gaps between adjacent elements collectively represent a major proportion of the area occupied by the screen.
16. A washer-drier according to Claim 10 or Claim II wherein, in the vicinity of the screen, the first and second ducts are co-linear and transverse to the third duct.
17. A washer-drier according to any one of Claims 6 to 16 wherein the screen is in the lowest part of the air flow path.
18. A washer-drier substantially as hereinbefore described with reference to the accompanying drawing.
19. Any novel feature or novel combinatiori of features disclosed herein and/or shown in the accompanying drawing.