Drum dryer

Abstract

Metal drum dryer, the side surface of which is constituted of U-shaped profiles (1), each having a bottom, each profile (1) is welded to the two neighbouring profiles (1) thereof and the bottom of each profile (1) is pierced with holes (4).

Claims

1. A dryer that comprises a housing (11) that has a hot air inlet (18), a metal drum (15) mounted rotatably about its axis (X) within the housing (11), a metal gauze (17) stretched around the side surface of the drum (15) and rotationally fixed, and means (A, B) for passing a cloth (C) to be dried over the gauze (17), characterised in that the side surface of the drum (15) is formed from U-shaped profiles that each have a bottom (2) pierced with holes (4) and two branches (3) passing radially towards the outside of the drum (15), each profile being fixed to its two neighbouring profiles by its branches (3), and wherein at least one of the branches of each profile has a notch into which a hoop penetrates.

2. The dryer according to claim 1, characterised in that the gauze (17) has openings of which the dimensions range from 0.5 to 3 mm, and the drum (15) has holes (4), the largest dimension of each hole (4) being from 40 to 150 mm.

3. The dryer according to claim 2, characterised in that the holes (4) are rectangular.

4. The dryer according to claim 1, characterised in that the height of the branches (3) in the radial direction ranges from 30 to 150 mm.

5. The dryer according to claim 4, characterised in that an opening percentage of the gauze (17) ranges from 25 to 75%.

6. The dryer according to claim 5, characterised in that an opening percentage of the bottom of each profile ranges from 10 to 70%.

7. The dryer according to claim 6, characterised in that the distance between two neighbouring holes (4) represents from 1.5 to 5 times the largest dimension of the holes (4) wherein the largest dimension of the holes (4) is between 40 and 150 mm.

8. The dryer according to claim 1, characterised in that the one or more plugs (22) is mounted on the inner surface of the U of the bottom (2) of the U-shaped profile.

9. The dryer according to claim 1, characterised h an increase in an opening percentage of the bottom (2) of each U-shaped profile (1), wherein the opening percentage is defined by dividing a surface area defined by the holes by a total surface area of the bottom, wherein a side of the metal drum nearest the hot air inlet has a smallest opening percentage, wherein a rate of increase in the opening percentage from the side of the metal drum nearest the hot air inlet to an opposite side of the metal drum along the drum length is between 3 and 6 times the smallest opening percentage and wherein the opening percentage of the bottom (2) of each U-shaped profile (1) is between 1.0 and 70%.

10. The dryer according to claim 1, characterised in that it only comprises one housing (11).

11. A dryer that comprises a housing (11) that has a hot air inlet (18), a metal drum (15) mounted rotatably about its axis (X) within the housing (11), a metal gauze (17) stretched around the side surface of the drum (15) and rotationally fixed, and means (A, B) for passing a cloth (C) to be dried over the gauze (17), characterised in that the side surface of the drum (15) is formed from U-shaped profiles that each have a bottom (2) pierced with holes and two branches (3) passing radially towards the outside of the drum (15), each profile being fixed to its two neighbouring profiles by its branches (3), and wherein one of the branches (3) of each profile is larger than the other branch (3) and the gauze (17) only rests on the largest branch (3) spaced apart from the smallest branch (3).

12. A dryer that comprises a housing (11) that has a hot air inlet (18), a metal drum (15) mounted rotatably about its axis (X) within the housing (11), a metal gauze (17) stretched around the side surface of the drum (15) and rotationally fixed, and means (A, B) for passing a cloth (C) to be dried over the gauze (17), characterised in that the side surface of the drum (15) is formed from U-shaped profiles that each have a bottom (2) pierced with holes and two branches (3) passing radially towards the outside of the drum (15), each profile being fixed to its two neighbouring profiles by its branches (3), characterised in that one or more plug(s) (22) for the holes (4) is slidably mounted on the bottom (2) of each U-shaped profile such as to clear or at least partially plug the holes (4).

13. A dryer that comprises a housing (11) that has a hot air inlet (18), a metal drum (15) mounted rotatably about its axis (X) within the housing (11), a metal gauze (17) stretched around the side surface of the drum (15) and rotationally fixed, and means (A, B) for passing a cloth (C) to be dried over the gauze (17), characterised in that the side surface of the drum (15) is formed from U-shaped profiles that each have a bottom (2) pierced with holes and two branches (3) passing radially towards the outside of the drum (15), each profile being fixed to its two neighbouring profiles by its branches (3), characterised by an increase in the opening percentage of the bottom (2) of each U-shaped profile (1), from each edge towards the centre of the drum.

14. The dryer according to claim 13, characterised in that an opening percentage of the bottom (2) of each U-shaped profile (1) is between 10 and 70%.

Description

(1) In the attached drawings, given purely by way of example:

(2) FIG. 1 is a perspective view of a drum used in the dryer according to the invention;

(3) FIG. 2 is a more detailed view of part of the side surface of a drum used in the dryer according to the invention;

(4) FIG. 3 is a partial view sectioned transversely to the axis of the drum of FIG. 1;

(5) FIG. 4 is a detailed view of the drum of FIG. 1;

(6) FIG. 5 is a sectional view of a dryer according to the invention;

(7) FIG. 6 is a sectional view of a version of the dryer;

(8) FIG. 7 is a sectional view along a vertical plane of a dryer according to the invention;

(9) FIG. 8 is a more detailed plan view of the bottom of a U-shaped profile of a drum used in the dryer according to the invention, and

(10) FIG. 9 is a side view.

(11) The steel drum shown in FIG. 1 comprises a plurality of U-shaped profiles or side members 1. As shown in FIG. 2, each one has a bottom 2 pierced with holes 4 and two branches 3 passing radially from the bottom 2 towards the outside of the drum. Each profile 1 is welded to its two neighbouring profiles by their branches 3 such as to form a continuous drum. The drum of FIG. 1 comprises seven hoops 5 distributed uniformly over the length of the drum and pushed down into notches 6 made in the branches 3 (see FIG. 4). As shown by FIG. 2, the number of holes 4 in the bottom increases from one front side to the other of the drum. Between the end of the drum located on the left, in FIG. 2, and the first hoop 5 there are, via the side member 1, four rectangular holes 4, whereas between the first and the second hoop, the bottoms have three holes 4, the number of holes 4 decreasing towards the right. Instead of or at the same time as increasing the number of holes, one may also increase the dimensions.

(12) FIG. 3 shows the branches 3A and 3B of each side member 1 which are of unequal length, the shortest branch of a side member being welded to the longest branch of the neighbouring side member 1.

(13) The dryer shown in FIG. 5 comprises a housing 11 subdivided by a partition 12 into one compartment 13 for processing and one compartment 14 for circulating air. A drum 15 is mounted rotatably about its axis X, being driven by a drive that is not shown in the compartment 13, and a fan 16 is mounted in the compartment 14. The fan sends air into the drum 15 and sends it back into the compartment 14, then 13. The textile cloth to be processed rests on a fine gauze 17 stretched around the side surface of the drum 15 and fixed by its edges to the latter. The air of the compartment 13 is reheated by one or more burners 18 in the case of using gas, or by exchangers in the case of using other energy sources such as steam or fuel oil.

(14) The dryer of FIG. 6 differs from that of FIG. 5 by the presence of a fixed internal housing 19 that makes it possible, by means of flaps, to regulate the throughput of air over the length of the dryer.

(15) FIG. 7 shows a preferred dryer according to the invention. The dryer comprises a drum 15 mounted rotatably within a single housing 11 for the circulation of hot air.

(16) The moist non-woven fabric to be dried C enters into the dryer via a turning roll 20. It rests on the surface of a gauze stretched over the rotating drum 15 when it passes through the inside of the housing 11. The housing 11 diffuses hot air over the non-woven fabric. This air is heated by a burner 18 or some other heating device such as exchangers. The hot air passes through the non-woven fabric to be dried and is sucked into the inside of the drum 15 by means which are not shown. The dried non-woven fabric D is evacuated from the dryer by a new turning roll 21. The hot air that has passed through the non-woven fabric and that has been sucked into the inside of the drum is then reheated by a burner or an exchanger 18 considered to be the air inlet of the housing, and is then redirected by a fan (not shown) towards the surface of the drum covered with gauze and covered with the non-woven fabric to be dried.

(17) FIG. 8 shows a U-shaped profile that has circular holes on the bottom. A plug 22 pierced with holes with the same dimensions and the same positioning as the holes in the bottom of the U-shaped profile slides via inserts 23 into oblong holes 24 on the internal surface of the U-shaped profile (on the outside of the drum) such as to partially plug the holes in the bottom of the U. Each U may have a number of plugs side by side such as to obtain an opening or a plug that can be varied over the whole length of each U and so over the whole suction width of the drum.

(18) FIG. 9 shows a sectional view of a U-shaped profile 2 to which a plug 22 is fixed by screws and nuts or via RIVKLE WWW-type inserts (rivets).