US3636639A - Dryer - Google Patents

Abstract

A laundry dryer having a rotatable drum and a fan to force heated air into the center of the drum. The heating means is located between two sheets, the first being supported by the casing and the second being rotatable with the drum. The second sheet has an air passage on each side of it thus ensuring that incoming air picks all the heat available from it to improve the heating efficiency.

Description

O Unlted States Patent 1151 3,636,639 Schuurink 1 Jan. 25, 1972 [54] DRYER 2,587,646 3 1952 O'Neil 1.34/1 33 3,270,436 9/1966 Fairgrieve ..34/133 [72] Inventor: Fredrlk Adolf Schuurink, 27, Fr. 42 056 2 l 69 t 4 Roosevemaan Breda, er a ds 3, 9, 9 Me zger ..3 I133 22 Filed; N 14 1969 Primary ExaminerCarroll B. Dority, Jr.

Attorney-Stevens, Davis, Miller & Mosher [21] App]. No.: 876,984

[57] ABSTRACT [30] Foreign Application Priority A laundry dryer having a rotatable drum and a fan to force Nov. 21, 1968 Netherlands ..68/16657 heated air the center The heating "18am is located between two sheets, the first being supported by the 52 U.S. c1 ..34/133 casing and seccmd being with the drum- The [51 Int. Cl ..F26b 11/02 second sheet has air passage on each side thus ensuring [58] Field ofSearch ..34/131 133 that inwming PiCkS the heat available prove the heating efficiency. [56] References Cited 5 Claims, 1 Drawing Figure UNITED STATES PATENTS I 2,486,058 10/1949 Patterson et a]. 34/ 133 X 8 H 3 v A 3 mfik 7 17 A W 3 34 i *14 12 l x i 13 3 18 7 m I V W A W A W PATENTED mas m2 AV A\\WA\WA\WAX\W DRYER This invention relates to a dryer and more particularly to a dryer for laundry, having a drum rotatable about an axis in a stationary casing, in which at least a portion of the drying air before entering the drum is passed by a fan along a heating device. In such dryers the outer encasing is heated by the heating device, this not only being disagreeable but also reduces the efficiency of the device.

The general object of the invention is to remove this disadvantage. To this end the heating device is provided between two sheets located inside the casing, said-sheets being cooled by air passing said sheets.

According to the invention one of the sheets can be fixed to the casing and the other sheet to the drum.

The invention can also be applied with advantage to a dryer already having a high efficiency, in which the drying air is supplied to an enclosure surrounding the fan. This fan blows the air through the central portion of one of the drums walls and the drum is provided with apertures to discharge the drying air, the drying air being brought back into the enclosure of the fan through a narrow opening at the rear end of the enclosure which empties into a duct communicating with the atmosphere. A discharge opening to the atmosphere is provided in the path along which the air is brought back through the casing and has, in this case, a sheet fixed to the casing which forms the rear wall of said return path and also forms together with the rear end of the enclosure, the narrow opening. The sheet fixed to the drum forms with the sheet fixed to the casing a first passage and the sheet fixed to the drum forms with the rear wall of the casing a second passage, both passages communicating with the atmosphere as well as with the space inside the enclosure of the fan.

Other objects and advantages will become apparent from the following description taken in connection with the accompanying drawing showing the dryer in which:

The single FIGURE is a vertical sectional view parallel with the axis of a preferred embodiment.

A drum 1 of the dryer rotatable about its horizontal axis has in its front wall 2 a filling opening 3, the rear wall 4 being formed as a frustum of a cone.

In the space formed by the conical rear wall 4 of the drum 1 is a pressure fan 5 with an enclosure 6, said fan supported by bearing in said rear wall 4 and adapted to blow air with a certain overpressure through said enclosure 6 into the drum 1.

The air is discharged from the drum 1 through apertures 7 in the front wall 2 along side the filling opening 3 and is then passed through the spaces between the portion of the front wall 2 of the drum 1 provided with apertures 7 and the wall 8 of the stationary casing, between the cylindrical wall 9 of the drum 1 and the wall 10 of the casing, and between the rear wall 4 of the drum and a sheet 11 fixed to the casing. The air then passes to an annular slit 12 between the rear end of the enclosure 6 and the inner edge 13 of the sheet 11. From there the air passes again through the enclosure 6 into the drying space.

In the described return path of the drying air there is provided an opening 19 communicating with the atmosphere, through which a portion of the drying air is discharged to the atmosphere.

A sheet 16 is fixed to the drum 1, e.g., by means of connecting ribs 14 which run between the enclosure 6 and the bearing 15 of the drum, the sheet 16 being spaced from the rear of the sheet 11. Between sheets 11 and [6 a heating device 17 is provided. The space between the sheets 11 and 16 communicates at one side with the atmosphere through an opening 20 and at the other side with the space inside the enclosure 6.

It should also be understood that the location of openings 19 (for discharge) and 20 (for entering air) are shown only for the purposes of convenient illustration and could be located elsewhere, preferably not next to each other, in a preferred embodiment.

This is also the case with the space between the sheet 16 and the stationaral rear wall 18 of the casing. The path of the air through the ryer IS indicated by arrows. By this arrangement the outer wall of the casing will not be heated, because during operation the sheets 11 and 16 will be cooled by the air passing along them.

In this way the dryer is not only more safe because the outer wall remains cool, but also a better efficiency is reached. lt appeared from tests that with the embodiment shown this efficiency is about 3 percent better than without the advantageous construction of the present invention.

Iclaim:

l. A dryer, especially for laundry, having a drum rotatable about an axis in a stationary casing, a fan to force at least a part of the drying air before entering the drum along a heating device, the heating device being located between two sheets located inside the casing, one of the sheets being fixed to the casing and the other sheet to the drum, the drying air being supplied to an enclosure surrounding the fan which blows the air through the central portion of one of the drum walls, the drum being provided with apertures to discharge the drying air, the drying air flowing back into the enclosure of the fan through a narrow opening at the rear end of the enclosure which is also connected to a duct communicating with the atmosphere through a discharge opening in the path along which the air is brought back through the casing, the sheet fixed to the casing forming one wall of said return path and forming together with the rear end of the enclosure the narrow opening, the sheet fixed to the drum forming with the sheet fixed to the casing the rear wall of the casing a second passage, both passages communicating with the atmosphere as well as with the space inside the enclosure of the fan.

2. A dryer, especially for laundry, comprising:

a. a drum rotatable about an aXi in a stationary casing;

b. a fan to blow air through said drum;

0. a first sheet supported by said casing;

d. a second sheet supported by said drum;

e. heating means between said first and second sheets;

f. means defining a first air passage between said first and second sheets;

g. means defining a second air passage between said second sheet and a wall of said casing;

h. means for passing air from said first and second passages through the fan to the drum and arranged so that air passes simultaneously on both sides of said second sheet.

3. The dryer of claim 2 in which said first sheet defines a passage for recirculating air on one side thereof and said first and second passages on the other side thereof.

4. The dryer of claim 2 in which the drum, fan and sheets are arranged coaxially.

5. The dryer of claim 4 in which said air passages are annular openings.

Claims (5)

1. A dryer, especially for laundry, having a drum rotatable about an axis in a stationary casing, a fan to force at least a part of the drying air before entering the drum along a heating device, the heating device being located between two sheets located inside the casing, one of the sheets being fixed to the casing and the other sheet to the drum, the drying air being supplied to an enclosure surrounding the fan which blows the air through the central portion of one of the drum walls, the drum being provided with apertures to discharge the drying air, the drying air flowing back into the enclosure of the fan through a narrow opening at the rear end of the enclosure which is also connected to a duct communicating with the atmosphere through a discharge opening in the path along which the air is brought back through the casing, the sheet fixed to the casing forming one wall of said return path and forming together with the rear end of the enclosure the narrow opening, the sheet fixed to the drum forming with the sheet fixed to the casing the rear wall of the casing a second passage, both passages communicating with the atmosphere as well as with the space inside the enclosure of the fan.

2. A dryer, especially for laundry, comprising: a. a drum rotatable about an axis in a stationary casing; b. a fan to blow air through said drum; c. a first sheet supported by said casing; d. a second sheet supported by said drum; e. heating means between said first and second sheets; f. means defining a first air passage between said first and second sheets; g. means defining a second air passage between said second sheet and a wall of said casing; h. means for passing air from said first and second passages through the fan to the drum and arranged so that air passes simultaneously on both sides of said second sheet.

3. The dryer of claim 2 in which said first sheet defines a passage for recirculating air on one side thereof and said first and second passages on the other side thereof.

4. The dryer of claim 2 in which the drum, fan and sheets are arranged coaxially.

5. The dryer of claim 4 in which said air passages are annular openings.

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