METHOD FOR DRYING SLAB-SHAPED MATERIALS AND DRYING DEVICE

Abstract

A method for drying building material slabs, in particular slabs containing gypsum, which are guided in floors (15) through an device divided into a drying pre-zone (2) and drying chambers and in which the slabs are brought into contact with drying air, characterized in that drying air is applied from the drying pre-zone (2) to the slabs in an area (1) arranged upstream of the pre-zone (2) and enclosed at least, with respect to the conveying direction of the boards, on both longitudinal sides and on the upper side.

Claims

1.-15. (canceled)

16. A method for drying building material slabs, wherein the method comprises guiding the slabs in floors through a device divided into a preliminary drying zone and drying chambers and in which the slabs are brought into contact with drying air, the drying air being applied from the preliminary drying zone to the slabs in an enclosed area which is arranged upstream of the preliminary drying zone and is enclosed, with respect to a conveying direction of the slabs, at least on both longitudinal sides and on an upper side thereof.

17. The method of claim 16, wherein the slabs comprise gypsum.

18. The method of claim 16, wherein exhaust air from the preliminary drying zone flows as drying air along the slabs in the enclosed area counter to a conveying direction of the slabs.

19. The method of claim 16, wherein the drying air from the enclosed area is fed to a chimney via a pipe.

20. The method of claim 19, wherein the drying air is withdrawn from the enclosed area by a fan inserted in the pipe.

21. The method of claim 16, wherein a supply of drying air into the enclosed area is controlled or regulated by temperature and/or humidity sensors.

22. The method of claim 16, wherein a slight negative pressure of 50 Pa or less, is generated in the enclosed area.

23. The method of claim 22, wherein the negative pressure is 25 Pa or less.

24. The method of claim 16, wherein a moisture content of air in the enclosed area is controlled to a value of less than 30 g per kilogram of air.

25. The method of claim 24, wherein the moisture content is controlled to a value of 20 g or less per kilogram of air.

26. The method of claim 16, wherein an air temperature of 35° to 60° C. is maintained in the enclosed area.

27. A device for drying building material slabs with drying air, wherein the device comprises floors and is divided into a preliminary drying zone and drying chambers, the preliminary drying zone being preceded by an enclosed area in which drying air from the preliminary drying zone can be applied to the slabs.

28. The device of claim 27, wherein the enclosed area has side walls and a top cover as well as inlet-side covers between shelves for receiving the slabs and is open towards the preliminary drying zone for an inlet of the drying air.

29. The device of claim 27, wherein the drying air can be withdrawn from the enclosed area by a fan which is introduced in a pipe.

30. The device of claim 29, wherein the pipe is connected to a chimney.

31. The device of claim 27, wherein the device further comprises a control or regulating device by which a supply of drying air to the enclosed area can be controlled or regulated by means of temperature and/or humidity sensors.

32. The device of claim 27, wherein the device further comprises a bypass line for discharging excess drying air from the preliminary drying zone.

33. The device of claim 32, wherein the bypass line is connected to a chimney which is connected to a pipe, the pipe having introduced therein a fan by which drying air can be withdrawn from the enclosed area.

Description

[0028] The invention is explained in more detail below with reference to the drawings. They show:

[0029] FIG. 1 an isometric view of an enclosed area in front of a prezone of a drying device for drying a board-shaped material, segment boards forming the outer wall being omitted,

[0030] FIG. 2 a vertical sectional view of the enclosed area in longitudinal direction along a sectional line II-II of FIG. 1,

[0031] FIG. 3 a vertical sectional view of the enclosed area along a sectional line III-III from FIG. 1, and

[0032] FIG. 4 a horizontal sectional view of the enclosed area along a sectional line IV-IV from FIG. 1.

[0033] An enclosed area 1 (FIGS. 1 to 4) extends between a charging zone 20 or feeding device and a pre-zone 2 of a drying device. In the area, the setting or curing process in the boards, in particular the gypsum boards, is completed. The pre-zone 2 is connected to the area 1 without transition and extends to a front wall 3 of the pre-zone 2, so that drying air flows from the pre-zone 2 into the area 1 and heats the boards to a temperature of up to 60° C. At the same time, a negative pressure and a humidity of less than 30 g of water per kilogram of air are maintained in area 1, so that the drying air absorbs moisture from the slabs and the setting process in them is supported.

[0034] In the ceiling area, the drying air is supplied through two protrusions 4, 5, each located laterally above and on either side of area 1. From the porches 4, 5, moisture-enriched air flows via intake pipes 6, 7 to a central exhaust pipe 8, which runs above area 1, comprises a fan 9 and passes into a chimney 10, which in turn is equipped with a filter system 11.

[0035] On the front wall 3 of the prezone 2, on one or both sides of the wall 3, there is an exhaust port 12 from which a bypass line 13 leads to a flange 14 through which the bypass line 13 is connected to the exhaust pipe 8, so that drying air is exhausted from the prezone 2, if necessary.

[0036] Inside, the zone 1 has floors 15 (FIG. 3) with rollers 16. The wall is formed by a plurality of segmental boards 17 (FIG. 4), which are preferably hinged to allow easy access to the interior of area 1 for inspection work and checks.

[0037] In the direction of the feed area for feeding the boards, sheet metal strips (not shown) are attached to the feed opening between the floors 15, which open only when the boards are fed through on the floors 15 to such an extent that the introduction of the boards is made possible, but the area 1 otherwise remains closed. Sealing elements are also provided on both sides of the boards at the feed opening.