USRE37557E1 - Board drying process and drier - Google Patents

Board drying process and drier Download PDF

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Publication number
USRE37557E1
USRE37557E1 US09/378,083 US37808399A USRE37557E US RE37557 E1 USRE37557 E1 US RE37557E1 US 37808399 A US37808399 A US 37808399A US RE37557 E USRE37557 E US RE37557E
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United States
Prior art keywords
air
drying
boards
heat exchanger
stage
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US09/378,083
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English (en)
Inventor
Freidrich Bahner
Manfred Braun
Gerhard Lehn
Karl Maurer
Manfred Schmidt
Josef Steinkuhl
Karl-Friedrich Lang
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Grenzebach BSH GmbH
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Babcock BSH AG
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Assigned to GRENZEBACH-BSH GMBH reassignment GRENZEBACH-BSH GMBH ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: BABCOCK-BSH AG, FORMERLY BUTTNER-SCHILDE-HAAS AG, NOW BABCOCK-BSH AG I.I. (IN LIQUIDATION)
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B3/00—Drying solid materials or objects by processes involving the application of heat
    • F26B3/28—Drying solid materials or objects by processes involving the application of heat by radiation, e.g. from the sun
    • F26B3/283—Drying solid materials or objects by processes involving the application of heat by radiation, e.g. from the sun in combination with convection
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B15/00—Machines or apparatus for drying objects with progressive movement; Machines or apparatus with progressive movement for drying batches of material in compact form
    • F26B15/10—Machines or apparatus for drying objects with progressive movement; Machines or apparatus with progressive movement for drying batches of material in compact form with movement in a path composed of one or more straight lines, e.g. compound, the movement being in alternate horizontal and vertical directions
    • F26B15/12—Machines or apparatus for drying objects with progressive movement; Machines or apparatus with progressive movement for drying batches of material in compact form with movement in a path composed of one or more straight lines, e.g. compound, the movement being in alternate horizontal and vertical directions the lines being all horizontal or slightly inclined
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B21/00—Arrangements or duct systems, e.g. in combination with pallet boxes, for supplying and controlling air or gases for drying solid materials or objects
    • F26B21/06—Controlling, e.g. regulating, parameters of gas supply
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B23/00—Heating arrangements
    • F26B23/001—Heating arrangements using waste heat
    • F26B23/002—Heating arrangements using waste heat recovered from dryer exhaust gases
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B23/00—Heating arrangements
    • F26B23/02—Heating arrangements using combustion heating
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B23/00—Heating arrangements
    • F26B23/10—Heating arrangements using tubes or passages containing heated fluids, e.g. acting as radiative elements; Closed-loop systems
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/10—Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working

Definitions

  • the supply of drying air can be done through longitudinal ventilation, cross ventilation or cross ventilation with nozzles.
  • longitudinal ventilation the drying air is supplied at one end of the drier, or, when the latter is subdivided into several zone at one end of a zone, and evacuated at the opposite end.
  • the air is supplied at several locations on the sides of the drier and evacuated at the opposite sides, whereby it is possible to achieve larger mass flows of drying air through the drier.
  • the largest air mass flows can be guided in the case of cross ventilation via nozzles through the so-called nozzle drier.
  • an air recirculation process wherein a large part of the drying air is recirculated.
  • This drying air also called recirculated air, is heated outside the inner drier space. Only a small part of the drying air is discharged as outgoing air and a part corresponding to the outgoing air is supplied from outside as fresh air.
  • a further drying process wherein a low consumption of primary energy is achieved by using the condensation heat of the outgoing air is known from DE-A 26 13 512.
  • This process is a two-stage process. In the first drying stage high temperatures and high air humidity are used and in the second drying stage low temperatures and low humidity are used. The drying efficiency of the first stage is two or three times greater than that of the second stage and the second drying stage is heated by the outgoing air of the first drying stage, due to the interposition of a heat exchanger.
  • the drying air is supplied in a recirculation process, namely in the first drying stage in the form of a longitudinal ventilation and in the second stage in the form of cross ventilation with a large mass flow of recirculated air.
  • the large recirculated air mass flow of the second stage and the resulting high consumption of secondary energy are the reasons why in practice this process has been replaced by the process of the invention.
  • the object of the invention to provide an improved process and drier for the drying of plasterboard and the like with the lowest possible consumption of primary and secondary energy.
  • the used primary energy should be kept as low as possible by using the waste heat and also the condensation heat of the outgoing air, without increasing the requirement for secondary energy due to the recirculation of large air mass flows.
  • the process for drying boards which are guided through a drier on decks contacts the boards with drying air in two stages A and B, whereby in stage A the drying is carried out in a recirculated-air process with high temperature and at least average air humidity and with a drying capability which is two to four times higher than in stage B, and in stage B the outgoing air of stage A can be guided through a heat exchanger arranged in the decks of the drier and the drying air at a low temperature and low humidity can be guided in counterflow to the outgoing air of stage A.
  • stage A drying air at a temperature of 150° to 300° C. and an air humidity of 0.2 to 0.8 can be supplied, drying air at a temperature of 120° to 200° C. and an air humidity of 0.2 to 0.8 is discharged, and a part thereof is directed into stage B, and in stage B drying air is supplied in the form of longitudinal ventilation, whereby the drying air with a temperature of 20° to 80° C. and an air humidity of 0.005 to 0.015 is supplied and drying air at a temperature of 80° to 110° C. and an air humidity of 0.03 to 0.1 is discharged.
  • the outgoing air leaving the heat exchanger in stage A B can be directed into a heat exchanger for preheating the drying air of stage B.
  • the drying air of stage A guided as recirculated air, can be heated by at least one burner, the drying air discharged from stage B being directed towards the burners.
  • the boards are at first dried in a preliminary drying stage, are subsequently dried in stage A and are .finally dried in stage B.
  • the boards are dried at first in stage B and subsequently in stage A.
  • a drier for drying boards with a conveying device for transporting boards arranged on decks through the drier, can have a section A with at least one zone, which has a supply device, an evacuation device and a recirculated-air channel with conveying means and a heating device for recirculated air, as well as means for the supply of incoming air and means for the discharge of outgoing air, and a section B with a supply device for drying air and an evacuation device for drying air which are arranged at opposite ends of the drier.
  • a heat exchanger can extend in the decks above the conveying device through the section B of the drier, and can have a supply device and an evacuation device which are arranged at opposite ends of the drier, whereby the supply device of the heat exchanger is connected with at least one means for discharging the outgoing air of section A.
  • the supply device of the heat exchanger and the supply device for the drying air of stage B can be arranged at opposite ends of the drier.
  • the drier can have a heat exchanger for preheating the drying air of section B, whose supply line is connected to the evacuation device of the first-mentioned heat exchanger.
  • the heating installation of section A can consist of burners and the evacuation device for drying air of section B can be connected with the incoming air lines of a burner.
  • the conveying device can have roller conveyors or belt conveyors.
  • the first-mentioned heat exchanger can have tubes running parallel to the travel direction.
  • the tubes can be interrupted by collectors arranged transversely to the travel direction and to which they are connected.
  • stage B the outgoing air of stage A with a high water vapor content, guided through the heat exchanger, is cooled down by the drying air with a lower temperature to the point that a part of the water vapor condensates.
  • the waste heat and condensation heat of the outgoing air of stage A reach the inside of the drier in the immediate environment of the boards to be dried and are transmitted to the boards in the form of radiation and convection heat. Heating devices arranged outside the drier are not required. Pipes for the recirculated air can be simplified or saved.
  • the primary energy is intensively utilized.
  • drying air Due to the fact that the drying air is guided in counterflow to the outgoing air of stage A guided through the heat exchanger, cooler drying air meets already cooled outgoing air. This insures the widest possible condensation of the water vapors contained in the outgoing air and improves the utilization of primary energy. The intensive utilization of the primary energy leads to considerable savings of primary energy.
  • stage B the drying is done at the most with one half of the drying power of stage A. Thereby a part of the heat is transferred to the boards through heat radiation, due to the arrangement of the heat exchanger in the decks of the drier. Therefore for the transfer of the second part of the heat through convection only a relatively small amount of drying heat is required.
  • the secondary energy required for guiding this relatively low amount of drying heat is considerably lower in the process of the invention than the one needed in processes with similar low consumption of primary energy.
  • the primary energy is utilized to the largest possible extent, without substantially increasing the need for secondary energy.
  • stage A the drying can take place according to the recirculated-air process, whereby drying air with a temperature of 150° to 300° C. and an air humidity of 0.2 to 0.8 is supplied and drying air with a temperature of 120° to 200° C. and an air humidity of 0.2 to 0.8 is discharged.
  • a part of this drying air is drawn from stage A as outgoing air and guided into the heat exchanger of stage B.
  • stage B the drying air is supplied through longitudinal ventilation, whereby drying air with a temperature of 20° to 80° C. and an air humidity of 0.005 to 0.015 is supplied and drying air at a temperature of 80° to 110° C. and an air humidity of 0.03 to 0.1 is discharged.
  • the primary energy is optimally used with the lowest possible consumption of secondary energy.
  • the process of the invention can dispense with the burner used in the third zone of the prior art process.
  • the mass flow needed in the process of the invention is even smaller than in the stage B, i.e. in the third zone of the prior art process.
  • the process parameters make possible such a reduced mass flow of the drying air in stage B, that the drying air can be supplied in the form of a simple longitudinal ventilation, i.e. the recirculation of the drying air and therefore the recirculated-air pipes can be fully dispensed with.
  • the total amount of secondary energy needed in the process of the invention taking into consideration the additionally required electric energy for guiding the outgoing air of stage A through the heat exchanger of stage B, is approximately as great as in the prior art process.
  • the invention can utilize a preheating of the drying air supplied to stage B in a second heat exchanger outside the-drier, through which the outgoing air leaving the stage B is guided.
  • stage B The heat contained in the drying air discharged from stage B is used by directing the drying air to the burners of stage A.
  • the process is particularly suited for drying gypsum plaster boards, which towards the end of the process are not supposed to be exposed to very high temperatures, because of the danger of gypsum calcination. Therefore after a preliminary drying, the boards are dried at first at high temperatures in the stage A and subsequently at lower temperatures in stage B. Besides this temperature course favors the starch migration which is needed for good cardboard bonding.
  • the alternative approach is particularly suited for drying boards, e.g. mineral-fiber boards, which could also be exposed in a dry state to higher temperatures.
  • the boards are predried in stage B and in stage A are dried to ultimate humidity.
  • the drying takes place at high temperature differences of drying air and boards, which leads to a particularly efficient utilization of primary energy.
  • a roller-conveyor drier or a belt drier according to the invention can have several roller conveyors or belts arranged on top of each other, is particularly well suited for incorporating a heat exchanger which thereby extends in the decks above roller conveyors or belts.
  • the heat exchanger can have heat exchanger tubes running parallel to the conveying device or can have heat exchanger plates.
  • the advantage of the tubes is a lesser danger of contamination of the heat exchanger, while the plates are easier to mount.
  • the heat exchanger When the heat exchanger is equipped with tubes, these are advantageously interrupted by collectors arranged transversely to the conveying direction, whereby the tubes are connected to these collectors.
  • collectors In the collectors the condensate can be collected and discharged from there.
  • the collectors also facilitate the cleaning of the tubes, since through them cleaning devices can be introduced into the tubes.
  • FIG. 1A is a process flow diagram of the invention prior art
  • FIG. 1B is a process flow diagram of the prior art invention (top).
  • FIG. 2 shows a deck of section B of the drier according to the invention in a perspective view
  • FIG. 3 is a cross section through the drier in section B:
  • FIG. 4 is a side view of a segment along lines 4 — 4 in FIG. 5;
  • FIG. 5 is a vertical cross section through a segment of the drier in section B along lines 6 , 6 .
  • a drier is provided with a conveying device for the transport of boards arranged on decks through the drier.
  • the drier can be built as a roller-conveyor drier or a belt drier, whereby the conveying device has several roller conveyors or conveyor belts arranged one on top of another.
  • the prior art drier shown in FIG. 1 B 1 A is subdivided in the travel direction of the boards into
  • a supplementary drying section 6 with two nozzle areas a supplementary drying section 6 with two nozzle areas.
  • the drier In each of the nozzle areas of the preliminary and supplementary drying sections 2 , 6 , the drier has a cross ventilation with nozzles and a fan 7 . In the introductory part of the preliminary drying section there is also a suction device 8 for drying air.
  • the drier has a supply device, an evacuation device and a recirculation channel 9 with conveying means and a heating device for the recirculated air.
  • the supply and evacuation devices are arranged respectively at opposite ends of a zone 2 , 3 , 4 , 5 whereby in the travel direction 1 of the boards the supply device of the first zone 3 is arranged at the end of zone 3 and the supply devices of the second and third zone 4 , 5 are arranged at the beginning of each of the zones 4 , 5 .
  • the conveying means and the heating device are arranged one after the other, starting from the evacuation device.
  • the conveying means and the heating device are provided in each zone.
  • Each of the heating devices has a burner 11 for oil or gas, an air connection 12 with a fan 13 and a fresh air connection 14 .
  • the heating device can have damper registers, e.g. with thermal oil.
  • Air supply lines 15 for the air supply of zones 3 , 4 , 5 are connected to the fans 13 for the burners 11 .
  • Air outlet lines 16 for the outgoing air of the first and second zones 3 , 4 branch out respectively between the fans 10 and the burners 11 of the recirculated air channels 9 .
  • An air supply line 17 is connected to the fan 7 of the second, i.e. last nozzle area of the preliminary drying section 2 .
  • the drier has also a heat exchanger 18 arranged outside the inner drier space, with supply and outlet lines 19 , 20 for outgoing air and supply and outlet lines 21 , 22 for fresh air.
  • the outgoing-air lines 16 of the two zones 3 , 4 are connected to the supply line 19 for outgoing air.
  • the outgoing line 20 for outgoing air ends in a chimney not shown in the drawing.
  • a fan 23 is arranged in the supply line 21 for fresh air .
  • the outlet line 22 for fresh air branches out into the incoming air lines 17 , 15 of the preliminary drying section 2 and of the three zones 3 , 4 , 5 and in an incoming air line 24 which leads to the fan 7 of the second, i.e. last nozzle area of the supplementary drying section 6 .
  • An outgoing air line 25 with a fan 26 leads outward from the preliminary drying section 2 .
  • the zones 3 , 4 , of section A and the zone 5 of section B of the drier are connected to each other so that an air exchange is possible between them.
  • the drier of the invention illustrated in diagram of FIG. 1 A 1 B is subdivided into
  • its preliminary drying section 2 has four nozzle areas.
  • a supplementary drying section is not provided.
  • the construction of the preliminary drying section 2 and of the section A with the two zones 3 , 4 correspond with the generic drier.
  • one heat exchanger 27 with a supply device and an evacuation device.
  • the supply and evacuation devices of the heat exchanger 27 and for the drying air are respectively arranged at opposite ends of zone 5 , whereby the supply device of the heat exchanger 27 and the evacuation device for drying air at the beginning of zone 5 are arranged in the travel direction 1 of the boards.
  • the evacuation device for drying air is connected with an air line 28 , wherein a fan 29 is arranged, and which branches out into the incoming air lines 15 for the incoming air of zones 3 , 4 of section A and the incoming air line 17 of the preliminary drying section 2 .
  • the drier has a heat exchanger 31 for preliminary heating of the fresh air, i.e. the drying air supplied to section B, with incoming and outgoing lines 32 , 33 for the outgoing air and with incoming and outgoing lines 34 , 35 for fresh air.
  • the supply line 32 for outgoing air is connected to the evacuation device of the heat exchanger 27 and is provided with a fan 36 .
  • the outlet line 33 for outgoing air ends in a chimney which is not shown in the drawing.
  • a fan 37 is arranged in the supply line 34 for fresh air .
  • the outlet line 35 for fresh air leads to the supply device for the drying air of section B.
  • a line 40 provided with a burner 38 and a fan 39 , for preheating the fresh air at the start of the drier and for regulating the temperature of the fresh air.
  • the zones 3 , 4 , 5 of the drier are subdivided into fields by vertical supports 41 arranged on both sides (see FIG. 2 ).
  • the supports 41 consist for instance of double T-sections (FIGS. 3, 4 , 5 ).
  • Each field has two side walls 42 , a ceiling 43 and a bottom 44 .
  • the side walls 42 , the ceiling 43 and the floor 44 are built as double walls and provided with insulating material. They are fastened to the supports 41 , whereby the side walls 42 are fastened for instance via hinges 45 to the rear supports 41 and via closures 46 to the front supports 41 .
  • roller supports 49 arranged on top of each other and fastened to the supports 41 extend horizontally.
  • the roller supports 49 consist for instance of U-shaped sections, whose bottoms are arranged vertically and whose arms are pointing outward.
  • cylinder-like rollers 50 of a roller conveyor arranged in succession, extend transversely to the travel direction 1 .
  • Each of the roller conveyors arranged on top of each other form the bottom of a rack wherein the boards are transported.
  • the rollers 50 are provided at their ends with pivots 51 , by means of which they are supported in the roller supports 49 .
  • sprockets 52 are located on the pivots 51 in front of the roller supports 49 .
  • a driven chain (not shown in the drawing) is guided over these sprockets 52 .
  • a chain can extend for instance over the entire conveying length of the drier and can drive the rollers of two superpositioned decks, in that in the lower deck it is guided above the rollers 50 over the chain wheels 52 and in the rack located thereabove it is guided underneath the rollers 50 over the chain wheels 52 .
  • zones 3 , 4 of section A there are also the supply device and the evacuation device for the recirculated air, whereby the supply device is located in the last field of the first zone and in the first field of the second zone 4 and the evacuation device is correspondingly located in the first field of the first zone 3 and in the last field of the second zone 4 .
  • FIG. 2 shows the layout of the supply and evacuation devices for drying air, as well as the arrangement of the heat exchanger 27 in a deck.
  • the supply device for drying air extends over the last two fields.
  • the evacuation device for drying air is arranged in the second field.
  • the supply device for the heat exchanger 27 is located in the first field and its evacuation device is located in the second last field of zone 5 .
  • each rack the supply device for drying air has in the upper deck area a plate-like nozzle 53 , extending over two fields and over the entire width of the roller conveyor, which has a lateral opening (not visible) for the incoming drying air and an opening 54 pointing into the deck against the travel direction 1 for the exiting drying air.
  • the nozzles 53 are provided with baffle plates on the inside.
  • the supply device for drying air has on each side of the drier an incoming air channel 55 extending over the length of the last field and the entire height of the drier and wherein end the lateral openings of the nozzles 53 .
  • the evacuation device In the second field of the section B, the evacuation device has a corresponding outgoing air channel 56 .
  • the flow direction of the drying air is indicated by arrows 57 .
  • the supply and evacuation devices of the heat exchanger 27 have respectively in each deck plate-like nozzle 57 [sic] 59 and 58 , arranged above the roller conveyor.
  • the nozzles 58 and 59 are also provided with baffle plates on the inside.
  • Each nozzle 58 has a lateral opening for the entering outgoing air and each nozzle 59 has a lateral opening for the exit of the outgoing air.
  • the flow direction of the outgoing air is indicated by arrows 60 .
  • Each of the lateral openings of the nozzles 58 , 59 also ends in a channel 61 , 62 , which extends over the entire length of the corresponding field and over the entire height of the drier.
  • each rack the nozzle 59 of the evacuation device of heat exchanger 27 is arranged underneath the nozzle 53 of the supply device for drying air and projects somewhat under the nozzle 53 .
  • the nozzle 58 of the supply device is arranged at the same level as the nozzle 59 of the evacuation device.
  • the heat exchanger 27 has tubes 63 and collectors 64 arranged at the same level.
  • the arrangements of the heat exchanger 27 consisting of a nozzle 58 , tubes 63 , collectors 64 and a nozzle 59 in the decks extend approximately over the entire length of the roller conveyor (whereby in FIG. 2 only every third roller tubes 63 is indicated). Such an arrangement is also located underneath the lowest deck.
  • FIGS. 3 to 5 which show the inner drier space in section B, the heat exchanger 27 is shown only in two uppermost decks, in the lowest deck and underneath the lowest deck. Thereby in the second uppermost rack and in the lowest rack only a few tubes 63 are shown.
  • the tubes 63 extend parallelly to the travel direction 1 from the nozzle 58 of the supply device to the nozzle 59 of the evacuation device, to which they are respectively connected.
  • the tubes 63 are interrupted by the collectors 64 arranged transversely to the travel direction 1 , to which they are connected by detachable connection elements 65 (shown only in FIG. 5 ).
  • the nozzles 58 and 59 are closed towards the inner space of the drier, with the exception of openings for the tubes 63 .
  • the tubes 63 can be staggered transversely to the travel direction 1 by half the distance between tubes. They can have a smooth surface and can be made of stainless steel, aluminum, galvanized or flame-aluminized sheet metal.
  • the collectors 64 can also be made of the same materials. They are for instance arranged at equal intervals, whereby a collector 64 is located in each field. However the distance between the collectors 64 can also be different, according to the degree of contamination of the tubes for instance, and can amount up to two to four field lengths. In these cases the tubes 63 between collectors 64 , e.g. in the fields without collectors, are held by supports (not shown in the drawing).
  • the for instance box-shaped collectors 64 with rectangular cross section and rounded edges are provided with two lateral covers 66 which can be unscrewed. They are fastened to the roller supports 49 via mountings 67 , 68 fastened to the covers 66 .
  • the mountings 67 , 68 consist for instance of metal sheet plates widening towards the covers 66 . They can also consist of sections.
  • the collectors 64 are connected to a vertical drainage pipe 70 .
  • the drainage pipes 70 abut for instance via a siphon in a drainage channel or via a drainage channel in a water recipient with a water column of for instance 30 mm.
  • the drainage pipe 70 is shown only in the lower decks.
  • the cross section of the tubes 63 is round. It can also be oval or elliptic, in order to increase the horizontal radiation surface.
  • the heat exchanger 27 can also have plates connected to the nozzles 58 , 59 , which are for instance arranged one on the other and supported fieldwise and are provided with cleaning devices.
  • the width of a roller conveyor is of about 3 to 4 meters, the length of a field for instance 2.40 m. In each field there are five to seven rollers 50 arranged one after the other.
  • the length of each of the zones 3 , 4 of section A equals 20 m, the length of zone 5 of section B 50 to 70 m.
  • the drier has 12 decks. The number of decks can vary between 8 and 14.
  • the boards are continuously moved on decks through the drier, by means of the driven rollers 50 of the roller conveyors.
  • two to four boards are arranged next to each other.
  • the boards are successively brought into contact with the drying air in a stage A and a stage B.
  • the gypsum plaster boards they are first dried in a preliminary drying stage.
  • the boards run through four nozzle areas of the preliminary drying section 2 .
  • the supply of drying air takes place in cross countercurrent with respect to the travel direction 1 , namely in the form of cross ventilations with nozzles arranged one after the other, whereby the drying air is supplied to the last nozzle area and is discharged by the exhaust 8 at the beginning of the first nozzle area.
  • the drying air discharged from the zone 5 of section B and directed to the preliminary drying section 2 has an air humidity of 0.04 to 0.05 (kg water per kg dry air) and a temperature of 100° C. After running through the preliminary drying section 2 , the humidity of the boards amounts to 42% and their temperature to 60° to 70° C.
  • stage A the boards run through the first and second zone 3 , 4 of section A and are thereby brought into contact with drying air at a flow velocity of approximately 7 to 15 m/s.
  • the supply of drying air takes place in the form of a longitudinal ventilation according to the recirculated-air process, whereby the drying air is supplied from the recirculated-air channels 9 through the supply devices of zones 3 , 4 and after passing through the zones 3 , 4 it is discharged through the evacuation device into the recirculated-air channels 9 , where it is reheated.
  • the supplied drying air has an average humidity of 0.3 to 0.5 and a high temperature of about 260° to 280° C.
  • the discharged drying air has a slightly higher humidity also of 0.3 to 0.5 and a temperature of for instance 170° C.
  • the drying air is supplied in countercurrent with respect to the travel direction 1 of the boards and in the second zone 4 it is guided in the same direction as the travel direction 1 .
  • the drying air supplied to the second zone 4 can have a slightly higher temperature and a slightly lower humidity than the drying air supplied to the first stage.
  • the pressure conditions in the air systems are set so that a certain amount of drying air from zone 5 of section B flows into the zone 4 of section A, and from the zone 4 of section A into the zone 3 of section A.
  • section A the boards are dried to a humidity of 10 to 12%.
  • the temperature continues to be approximately 100° C.
  • stage B the boards run through the zone 5 of section B.
  • the supply of drying air takes place in the form of a longitudinal ventilation in countercurrent to the travel direction 1 of the boards.
  • stage B the outgoing air of stage A is guided through the heat exchanger 27 arranged in the decks of zone 5 in the same flow direction as the travel direction 1 . This way the drying air of stage B and the outgoing air of stage A are guided in countercurrent to each other.
  • the outgoing air of stage A is aspirated from the recirculated-air channel 9 of zones 3 , 4 between the fans 10 and the burners 11 and directed through the lines 16 and 30 to the supply device of the heat exchanger 27 . It is fed via nozzles 58 into the tubes 63 , traverses the tubes 63 and the collectors 64 and is discharged via the nozzles 59 of the evacuation device of heat exchanger 27 . Thereby a part of the water vapor contained in the outgoing air condensates. The condensate is collected in collectors 64 and directed via the drainage lines 69 to the drainage pipe 70 and the drainage channel.
  • the outgoing air is guided via the discharge line 35 through the heat exchanger 31 to the chimney.
  • fresh air aspirated from the outside by the fan 37 is heated and supplied to the via the discharge line 35 to the supply device for drying air.
  • burner 38 When the drier is started, optionally fresh air aspirated by the fan 39 is heated in burner 38 and directed via the discharge line 35 to the supply device for drying air.
  • the burner 38 can also be used for regulating the temperature of the drying air fed to the supply device.
  • the drying air supplied through the nozzles 53 of the supply device has a humidity corresponding to the normal humidity of the ambient air of 0.005 to 0.015 and a temperature of e.g. 60° C. While passing through the zone 5 of section B the humidity of the drying air increases to 0.04 to 0.05 and its temperature increases to about 100° C.
  • This drying air is discharged through the discharge channel 55 of the evacuation device and supplied to the burners 11 of the zones 3 , 4 of section A via the air lines 28 and the incoming air lines 15 to the burners 11 of zones 3 , 4 , and over the air line 28 and the incoming air line 17 to the preliminary drying section 2 , as already mentioned.
  • stage B for drying the boards the heat is transferred to the boards through convection, as well as through radiation.
  • the boards are brought into contact with the drying air which was preheated in the heat exchanger 31 and which is heated inside the drier through contact with the heat exchanger surfaces of the heat exchanger 27 .
  • the flow velocity is also set at 7 to 15 m/s. Due to the low temperature level there is no danger of the boards being overdried by heat radiation.
  • the heat transfer through radiation takes place over the heat exchanger surfaces of the heat exchanger 27 arranged in the decks of the drier, i.e. through nozzles 57 of the supply device, the tubes 60 63 , the collectors 61 and the nozzles 58 of the discharge device.
  • the heat amounts transferred to the boards by convection and radiation are approximately equal. Thereby the boards are dried to a humidity of ⁇ 0.3%. When they leave section B their temperature is 60° C., so that cooling or associationalization are no longer needed.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Microbiology (AREA)
  • Drying Of Solid Materials (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
  • Devices For Post-Treatments, Processing, Supply, Discharge, And Other Processes (AREA)
US09/378,083 1993-08-11 1994-07-27 Board drying process and drier Expired - Lifetime USRE37557E1 (en)

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DE4326877A DE4326877C1 (de) 1993-08-11 1993-08-11 Verfahren zum Trocknen von Platten und Trockner
DE4326877.3 1993-08-11
PCT/EP1994/002479 WO1995004908A1 (fr) 1993-08-11 1994-07-27 Procede et dispositif de sechage de panneaux
US09/378,083 USRE37557E1 (en) 1993-08-11 1994-07-27 Board drying process and drier
US08/591,545 US5659975A (en) 1993-08-11 1994-07-27 Board drying process and drier

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US (2) USRE37557E1 (fr)
EP (1) EP0712481B1 (fr)
JP (1) JP2664000B2 (fr)
AT (1) ATE159806T1 (fr)
AU (1) AU7609694A (fr)
CA (1) CA2169305C (fr)
DE (2) DE4326877C1 (fr)
ES (1) ES2109013T3 (fr)
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080276488A1 (en) * 2007-05-07 2008-11-13 Paul Seidl Step air foil web stabilizer
US20080282575A1 (en) * 2005-04-13 2008-11-20 Lindauer Dornier Gesellschaft Mbh Multistage Continuous Dryer, Especially For Plate-Shaped Products
US20140190661A1 (en) * 2013-01-09 2014-07-10 Thesan S.P.A. Air exchange device for buildings
US9983574B2 (en) 2013-09-30 2018-05-29 United States Gypsum Company Systems and methods for controlling a conveyor system during product changeovers

Families Citing this family (36)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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DE19955147C2 (de) 1999-11-17 2002-02-28 Babcock Bsh Gmbh Rollenbahntrockner
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WO2023227246A1 (fr) * 2022-05-25 2023-11-30 Knauf Gips Kg Dispositif et procédé de séchage de panneaux de construction
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Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1399276A (en) * 1920-01-17 1921-12-06 Beaver Company Drier for plaster-board
DE505017C (de) * 1926-11-11 1930-08-12 Werner Brunnschweiler Kanalstufentrockner
US2266489A (en) * 1938-07-22 1941-12-16 United States Gypsum Co Gypsum board, drying method
US2329581A (en) * 1937-10-21 1943-09-14 Bernstein Rudolf Apparatus for drying material by utilizing vapor heat
US2590849A (en) * 1947-12-31 1952-04-01 Dungler Julien Method for drying fibrous sheet material
US3374106A (en) * 1964-05-14 1968-03-19 Proctor & Schwartz Inc Material drying method and apparatus
FR2311261A1 (fr) * 1975-05-12 1976-12-10 Electricite De France Procede et installation de sechage de plaques de gypse
DE2613512A1 (de) * 1976-03-30 1977-10-06 Buettner Schilde Haas Ag Zweistufiges trocknungsverfahren und trocknungsanlage
DE2941037A1 (de) * 1978-10-13 1980-04-30 Svenska Traeforskningsinst Warmluft-trockenverfahren
US4242808A (en) * 1978-11-22 1981-01-06 Ingersoll-Rand Company Paper web drying system and process
US4697354A (en) * 1985-08-28 1987-10-06 Babcock Textilmaschinen Gmbh Drier for moving sheet material
FR2614092A1 (fr) * 1987-04-17 1988-10-21 Bertin & Cie Procede et installation de sechage d'un produit humide
US4872270A (en) * 1988-03-09 1989-10-10 Eastman Kodak Company Drying process
US5212877A (en) * 1990-07-24 1993-05-25 Pagendarm Gmbh Method of and apparatus for drying coated substrates
US5244518A (en) * 1990-11-02 1993-09-14 Stickle Steam Specialties Co. Inc. Corrugated board manufacturing apparatus and process including precise web moisture and temperature control

Patent Citations (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1399276A (en) * 1920-01-17 1921-12-06 Beaver Company Drier for plaster-board
DE505017C (de) * 1926-11-11 1930-08-12 Werner Brunnschweiler Kanalstufentrockner
US2329581A (en) * 1937-10-21 1943-09-14 Bernstein Rudolf Apparatus for drying material by utilizing vapor heat
US2266489A (en) * 1938-07-22 1941-12-16 United States Gypsum Co Gypsum board, drying method
US2590849A (en) * 1947-12-31 1952-04-01 Dungler Julien Method for drying fibrous sheet material
US3374106A (en) * 1964-05-14 1968-03-19 Proctor & Schwartz Inc Material drying method and apparatus
FR2311261A1 (fr) * 1975-05-12 1976-12-10 Electricite De France Procede et installation de sechage de plaques de gypse
US4312136A (en) * 1976-03-30 1982-01-26 Buettner-Schilde-Haas Ag Arrangement and method of drying articles
DE2613512A1 (de) * 1976-03-30 1977-10-06 Buettner Schilde Haas Ag Zweistufiges trocknungsverfahren und trocknungsanlage
DE2941037A1 (de) * 1978-10-13 1980-04-30 Svenska Traeforskningsinst Warmluft-trockenverfahren
US4242808A (en) * 1978-11-22 1981-01-06 Ingersoll-Rand Company Paper web drying system and process
US4697354A (en) * 1985-08-28 1987-10-06 Babcock Textilmaschinen Gmbh Drier for moving sheet material
FR2614092A1 (fr) * 1987-04-17 1988-10-21 Bertin & Cie Procede et installation de sechage d'un produit humide
US4872270A (en) * 1988-03-09 1989-10-10 Eastman Kodak Company Drying process
US5212877A (en) * 1990-07-24 1993-05-25 Pagendarm Gmbh Method of and apparatus for drying coated substrates
US5244518A (en) * 1990-11-02 1993-09-14 Stickle Steam Specialties Co. Inc. Corrugated board manufacturing apparatus and process including precise web moisture and temperature control

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
"Planung, Bau und erste Betrieberfahrungen mit einer Productionsanlage fur Gip-Wansbauplatten" by Bloech et al., published in ZEMENT_KALK-GIPS, No. Aug. 1991 (44th year).*
Trockungstechnik Third Volume K. Kroll "Drying and Driers in Production" by W. Kast, pp. 489-496, 1989. *

Cited By (8)

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Publication number Priority date Publication date Assignee Title
US20080282575A1 (en) * 2005-04-13 2008-11-20 Lindauer Dornier Gesellschaft Mbh Multistage Continuous Dryer, Especially For Plate-Shaped Products
US7997003B2 (en) * 2005-04-13 2011-08-16 Lindauer Dornier Gesellschaft Mbh Multistage continuous dryer, especially for plate-shaped products
US20080276488A1 (en) * 2007-05-07 2008-11-13 Paul Seidl Step air foil web stabilizer
US8061055B2 (en) * 2007-05-07 2011-11-22 Megtec Systems, Inc. Step air foil web stabilizer
US20140190661A1 (en) * 2013-01-09 2014-07-10 Thesan S.P.A. Air exchange device for buildings
US9983574B2 (en) 2013-09-30 2018-05-29 United States Gypsum Company Systems and methods for controlling a conveyor system during product changeovers
US10289104B2 (en) 2013-09-30 2019-05-14 United States Gypsum Company Systems and methods for controlling a conveyor system during product changeovers
US11126169B2 (en) 2013-09-30 2021-09-21 United States Gypsum Company Systems and methods for controlling a conveyor system during product changeovers

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ES2109013T3 (es) 1998-01-01
JPH08512399A (ja) 1996-12-24
ATE159806T1 (de) 1997-11-15
AU7609694A (en) 1995-02-28
DE4326877C1 (de) 1994-10-13
JP2664000B2 (ja) 1997-10-15
US5659975A (en) 1997-08-26
DE59404486D1 (de) 1997-12-04
EP0712481B1 (fr) 1997-10-29
EP0712481A1 (fr) 1996-05-22
WO1995004908A1 (fr) 1995-02-16
CA2169305C (fr) 2001-10-30
CA2169305A1 (fr) 1995-02-16

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