DRYER FOR DRYING A PANEL-SHAPED PRODUCT

Abstract

A dryer for drying a strip or panel-shaped product, in particular gypsum board or veneer panels, having a plurality of tiers, having an outer and an inner housing and an inner housing separated from the outer housing by a first and second partition wall, having conveying devices for conveying the product, upper and lower nozzle boxes arranged transversely to the conveying direction and extend over the width of the conveying devices between the dividing walls, have in each case one inflow opening on one end assigned to the first separating wall and are closed on the other end assigned to the second partition wall. Nozzle openings for blowing out drying air are present at least on one side of the product passing through. The dryer includes at least on the first partition wall adjustable adjusting plates wherein the inflow openings of the upper and lower nozzle boxes can be adjusted.

Claims

1. A dryer for drying a strip-like or plate-like material having a plurality of tiers, having an outer housing and an inner housing separated from the outer housing, with conveying means for conveying the material and with upper and lower nozzle boxes arranged transversely to the conveying direction, which extend over the width of the conveying means between the partition walls, wherein the nozzle boxes each having an inflow opening at one end associated with the first partition wall and being closed at the other end associated with the second partition wall, and the nozzle boxes being provided with nozzle openings for blowing drying air at least onto one side of the material passing through, wherein adjustable baffle plates are provided at least on the first partition wall, by means of which the inflow openings of the upper and lower nozzle boxes can be adjusted.

2. The dryer according to claim 1, wherein the adjusting plates are adjustable in stages.

3. The dryer according to claim 1, wherein the openings to the respective upper and lower nozzle boxes are adjustable jointly by the adjusting plates per level.

4. The dryer according to claim 1, wherein the cross-sections of the inflow openings of the nozzle boxes are fixable from above by the adjustment of the adjusting plates.

5. The dryer according to claim 1, wherein the adjusting plates are fixable at predetermined positions.

6. The dryer according to claim 1, wherein the adjusting plates are adjustable electrically.

7. The dryer according to claim 1, wherein openings or doors are provided in the outer housing, by means of which the adjusting plates are adjustable mechanically.

8. The dryer according to claim 1, wherein the adjusting plates are adjustable by means of a transmission.

9. The dryer according to claim 1, wherein sensors for measuring the drying effect of the drying air are present and that the adjusting plates are adjustable in such a way that the drying effect is evened out on all levels.

10. The dryer according to claim 1, wherein the air flow in the nozzle boxes is increased by up to 20% by lifting the adjusting plates and is lowered by up to 20% by lowering the blend sheets.

11. The dryer according to claim 1, wherein in order to compensate for flow differences, the air flow in the respective lower nozzle boxes is stronger than in the upper nozzle boxes.

Description

[0021] The invention is explained in more detail below in an exemplary embodiment with reference to the drawings, in which:

[0022] FIG. 1 shows a cross-section of a dryer according to the prior art equipped with partitions and in the region between the partition walls with nozzle boxes,

[0023] FIG. 2a shows a plan view of the opening-side partition of a dryer according to the invention with openings of nozzle boxes, which are partially covered by adjusting plates, slightly enlarged compared to the illustration in FIG. 1,

[0024] FIG. 2b shows the separating wall equipped with the adjusting plates according to FIG. 2a in cross-section,

[0025] FIG. 3a shows a further plan view of an arrangement of adjusting plates mounted on a partition for upper and lower nozzle boxes, which are jointly adjustable, and

[0026] FIG. 3b shows the separating wall according to FIG. 3a equipped with the adjusting plates according to FIG. 3a in cross-section.

[0027] A known dryer (FIG. 1) consists, for example, of thirty or more parts lined up next to one another in a modular manner. A compartment measures 2.0 m to 2.5 m in the conveying direction and is 5.0 m to 6.0 m wide. It has a ceiling 1 and outer side walls 2, 3 which form the outer housing.

[0028] In the compartment, a core region 7 is separated from a circulating air channel by an intermediate ceiling 4, a partition wall 5 and a partition wall 6 equipped with outlet openings, which can also be designed as a lattice frame. The latter consists of a horizontal channel 8 above the core region 7, a lateral vertical distributor channel 9 and a collecting channel 10 arranged substantially mirror-symmetrically on the opposite side. In the core region 7, rollers 11 are arranged in a plurality of planes, for example approximately eight to twelve planes, which lie one above the other at equal distances of approximately 250 to 350 mm, which rollers 11 are mounted on the separating walls 5, 6. The rollers 11 can be driven at the same speed by chains (not shown); they therefore form a roller conveyor in each tier which extends over the entire length of the dryer.

[0029] Below and above the transport planes in which the plates lying on the individual roller conveyors move continuously through the dryer, nozzle boxes 14 a, 14 b, which extend over the width of the roller conveyor, are arranged in the interspaces of adjacent rollers 11. The boundary wall of the nozzle boxes 14a, 14b facing the transport plane is provided with nozzle openings (likewise not shown here) for inflating drying air onto continuous plates of the product to be dried, for example the gypsum or veneer panels. One end of the nozzle boxes 14a, 14b is designed as an inflow opening in the partition wall 5, and the other end 18 is closed. The nozzle boxes 14 a, 14 b are wedge-shaped so that their cross-section continuously decreases in the direction of the closed end 18. Between adjacent transport planes, an upper nozzle box 14 a is mechanically connected to an immediately underlying nozzle box 14 b in the region of the openings, so that they form a double box and have, for example, a common inflow opening. Alternatively, the nozzle boxes 14a, 14b have separate openings. The end, at which the inflow opening is located, fits snugly in a rectangular recess in the partition wall 5. It is fastened immovably to the partition wall 5 and is sealed all around by a collar.

[0030] The horizontal channel 8 is divided into a suction chamber 21 and a pressure chamber 22 by means of a partition plate 20 which is shaped like a staircase. The suction chamber 21 is in open connection with the collecting channel 8, the pressure chamber 22 with the distributor channel 9. Centrally in the horizontal channel 8, specifically in the pressure chamber 22 separated by the separating plate 20, a free-running, housing-free radial impeller 23 is accommodated, whose drive shaft penetrates the ceiling 1 and is coupled to a drive 24 seated on the ceiling 1. An opening in a horizontal region of the separating plate 20 corresponds to the suction funnel 25 of the radial impeller 23, so that the radial impeller 23 is connected on the suction side to the suction chamber 21.

[0031] In a similar embodiment, as shown in FIG. 1 on the basis of the prior art, inflow openings 26 of the nozzle boxes 14a, 14b are provided in the partition wall 6 (FIGS. 2a, 2b) according to the invention. By means of adjusting plates 27 which can be lowered in each case from above, the openings 26 are partially closed in order to reduce the inflow of the warm drying air, in particular in the lower levels of the nozzle boxes 14a, 14b.

[0032] The adjusting plates 27 are jointly adjusted in each case. For this purpose, they are connected to one another by a frame.

[0033] In a further embodiment (FIGS. 3a and 3b), the openings 26 of the upper and lower nozzle boxes 14a, 14b are partially covered from above in each tier of the dryer by interconnected adjusting plates 27a and 27b. The adjusting plates 27a, 27b are connected to one another by webs 28. Its adjustment range is determined by elongated holes 29 between the upper adjusting plates 27a. Mandrels 30 attached to the partition wall 5 project into the elongated holes 29.