Method for producing binder using thermal energy and method for drying sheet produced using binder in drying device

Abstract

The invention relates to a combined method comprising a method for producing or treating a binder using thermal energy in a first device (100) and a method for drying a sheet material produced using the binder in a second device designed as a drying device (1), in which waste heat generated in the first device is recovered by means of at least one heat recovery device, and at least partially feeding the waste heat to a second device in which the waste heat is used to dry the sheet material.

Description

Technical Field

[0001] The present invention relates to a coupled method (gekoppeltes Verfahren), comprising a method for producing a binder using thermal energy in a first device and a method for drying a board produced using the binder in a second device designed as a drying device, wherein waste heat generated in the first device is recovered by at least one heat recovery device and at least partially supplied to the second device, where the waste heat is used for drying the board in the second device. Background Art

[0002] During calcination, building materials or binders, especially calcium-containing minerals, are heated in the presence of air or in an oxygen-containing atmosphere to dehydrate or condition the minerals. An example of a calcination method is lime calcination, which produces water, calcium oxide, and carbon dioxide as decomposition products. The calcination methods for magnesite and dolomite are similar. In gypsum production, the crystal water in calcium sulfate dihydrate is removed. When particles sinter together, the firing of clay and porcelain also causes the combined water to escape. Calcination is also used in the production of cement and alumina; rotary kilns are commonly used for calcination. Binders for finished building material mixtures or building material boards can also be prepared in a usable state by heating in a rotary kiln.

[0003] Hereinafter, the device used for calcination is referred to as a calciner. In the context of the present invention, a calciner is understood to be any form of device suitable for calcination, such as an indirectly heated rotary kiln, an indirectly heated furnace, a steam-heated calciner, or even a traditional hammer mill or roller ball mill that has been retrofitted with electric heating.

[0004] All calcination methods require high energy consumption and high temperatures. For example, in the case of calcining clay, the temperature reaches above 800 °C; in the case of calcining gypsum, a temperature between 150 °C and 400 °C is used. For example, refer to WO 2012 / 028251A1.

[0005] In addition to energy consumption, the calcination process generally requires active cooling of the calcined minerals.

[0006] On the other hand, when drying building boards (such as gypsum boards, gypsum fiber boards, cement boards, and other building material boards), problems arise in that fuel (i.e., primary energy) is required to heat the drying air, for example, through a burner or a heating component, and electrical energy (i.e., secondary energy) is required to supply air through a blower. To achieve more efficient board production, the use of primary energy and secondary energy must be reduced.

[0007] DE 26 13 512 A1 discloses a drying method carried out in a drying device, in which low primary energy consumption is achieved by utilizing the condensation heat of the exhaust gas. The method is designed in two stages. In the first drying stage, drying is carried out at high temperature and high humidity, while in the second drying stage, drying is carried out at low temperature and low humidity, so that the drying capacity in the first stage is two to three times that in the second stage, and the second drying stage is heated by using the exhaust gas from the first drying stage through a heat exchanger. In both stages, the drying air is supplied in a recirculation manner, in the form of longitudinal air supply in the first drying stage and in the form of transverse air supply with a large recirculation mass flow in the second drying stage. However, the second stage requires a large recirculation mass flow, resulting in high consumption of secondary energy. Summary of the Invention

[0008] The object of the present invention is to reduce the overall energy consumption in the production of building boards, especially to make the use of thermal energy more economical and environmentally friendly.

[0009] According to the present invention, this object is solved by the technical solution described in claim 1.

[0010] By means of the present invention, the reuse of thermal energy generated during the calcination or conditioning of building materials can be achieved, thereby reducing the overall energy consumption in the production of building boards.

[0011] According to the present invention, waste heat generated in a first device is recovered by at least one heat pump and at least partially supplied to a second device, where the waste heat is used to dry the boards.

[0012] According to the present invention, most of the thermal energy is supplied to at least one heat pump, which in turn transfers the thermal energy to a pipeline that is directly or indirectly connected to at least one part or area of the drying device.

[0013] Compared with the method proposed in patent application DE 10 2022 000 627.8, the remaining energy requirement of the drying device is significantly reduced, preferably by half. The front area of the drying device can preferably adopt a lightweight structure for its housing, thus saving material costs.

[0014] Advantageous further improvements can be derived from the dependent claims and the description, especially in conjunction with the drawings.

[0015] The present invention is particularly used in combination with a calciner, from which heat energy is supplied to a drying device. Generally, according to the present invention, in the calciner, the same building material is pre-prepared, heated or prepared for subsequent manufacturing processes, and the building material is then processed into a plate in another device, and then the plate is dried in the drying device using at least part of the waste heat from the first device; however, the present invention does not exclude the possibility of processing, heating or drying different building materials or binders in the first device and the second device.

[0016] For example, the calciner is designed as a directly heated or indirectly heated rotary kiln. Optionally, a thermal furnace can be used, which can also be heated directly or indirectly; steam can also be used for heating. Conventional hammer mills and roller mills can also be used for calcination. When the hammer mill or roller mill is modified, very high energy efficiency can be obtained.

[0017] Therefore, the present invention relates to a combined method in which, while processing and heating a building material, an insulating material or a binder in a first device designed as a rotary kiln, the waste heat from the rotary kiln is supplied to at least one heat recovery device, and then the waste heat is supplied to a second device through the heat recovery device.

[0018] A preferred feature of the combined method is that heat is recovered in at least one heat pump through at least one heat recovery device. The heat pump is arranged close to the first device, and the heat pump is a high-temperature heat pump because the inlet temperature of the air discharged from the first device is already very high, and this inlet temperature is raised to an even higher value by the heat pump.

[0019] The heat is transferred from the heat pump to the second device through at least one heat exchanger.

[0020] Preferably, gypsum or cement clinker is calcined in the rotary kiln, and the plate containing gypsum or cement clinker is dried in the second device.

[0021] It is advantageous when gypsum boards or cement boards are produced from gypsum heated in the rotary kiln or cement clinker heated in the rotary kiln during an intermediate process, and the gypsum boards or cement boards are dried in the second device. Therefore, the present invention also includes the following use: using part of the heat lost in the first device for the manufacturing process or manufacturing steps of the intermediate process before using the heat in the second device (i.e., the drying device).

[0022] When the heated air from the heat recovery device is sent into the second device designed as a drying device, the energy input in the second device is significantly reduced. For example, 50% to 100% of the energy can be provided for the second device through the heat recovery device.

[0023] In a particular embodiment of the present invention, energy (e.g., in the form of hot air) is supplied to at least one front part of the second device with respect to the sheet conveying direction.

[0024] Preferably, the method according to the present invention is characterized in that the sheet passes through a first stage (A) and a second stage (B) in the drying device, wherein both stages (A, B) include laminates, the sheet is placed on the surfaces formed in each laminate, and passes through the drying device in the laminates of the two stages (A, B) respectively, wherein the sheet is in contact with high-temperature drying air and dried in the first stage (A), and dried with lower-temperature drying air in the second stage (B), wherein the sheet is heated at least in the first stage by hot air generated by direct heating of a heat exchanger, a heat pump, a wet separator, a calciner or by hot steam, heat-conducting oil, indirect electric heating or low calorific value heat sources, and wherein at most a single device is provided for recovering the heat supplied to the sheet in the second stage. Preferably, the front part and the rear part of the second device have the same number of laminates.

[0025] According to the present invention, the combined method ensures that the sheet is dried by circulating air at least in the first stage. At a high temperature between 90 °C and 160 °C, preferably between 120 °C and 140 °C, the air absorbs a large amount of moisture, so that the dew point is between 60 °C and 99 °C, preferably the dew point is between 75 °C and 90 °C; in this way, a large amount of moisture can be converted into liquid by cooling the saturated water vapor air, and the phase change enthalpy can be recovered by condensation in the heat exchanger in the area of the second device.

[0026] Preferably, the method is characterized in that the sheet is dried at least substantially by using a nozzle box in the area of at least the first stage (A).

[0027] According to one embodiment, the sheet is dried by drying air at a temperature between 20 °C and 90 °C in the second stage (B).

[0028] According to one embodiment, the exhaust gas from the first stage (A) is supplied to a heat exchanger (31) for preheating the drying air of the second stage (B).

[0029] It has been proven advantageous when the sheet is first dried in a pre-drying stage upstream of the first stage (A), then dried in the first stage (A), and finally dried in the second stage (B).

[0030] It is also advantageous when the sheet is conveyed through the sections (2) in the stages (A, B) by separate conveying devices for each stage (A, B).

[0031] In another embodiment, the sheet is guided in the second stage (B) with a greater number of laminates than in the first stage (A); the stages (A, B) can be arranged, for example, one above the other or side by side with respect to each other.

[0032] When drying the sheet, in particular when drying building sheets containing cement and gypsum, the sheet conveyed through the drying device is brought into contact with heated air.

[0033] The drying air can be supplied in the form of longitudinal air supply, transverse air supply or transverse air supply using a nozzle box equipped with nozzles. In longitudinal air supply, the drying air is fed in at one end of the drying device (or supplied at one end of a zone if the drying device is divided into several zones) and discharged at the opposite end.

[0034] In transverse air supply, the drying air is fed in at several positions on the side of the drying device and discharged at the opposite side, so that the drying in the drying device is more thorough. Particularly intensive drying is achieved by transverse air supply via nozzles in the form of turbulence in the nozzle drying device.

[0035] Preferably, the sheet is dried in the first stage A with drying air at a temperature between 90 °C and 160 °C, although in other embodiments of the present invention, an intermediate temperature in the range of 120 °C to 140 °C can also be selected. Selecting a low temperature enables gentle drying of the sheet. This prevents the formation of anhydrite in the sheet.

[0036] When the sheet is dried in the first stage A within these temperature ranges, the hot air absorbs a large amount of moisture, and preferably the temperature and circulation speed of the air are selected such that the dew point of the hot air is in the range between 60 °C and 99 °C.

[0037] The drying zone of the first stage A has transverse air supply (for example, without a nozzle box) or has longitudinal air supply. In a preferred embodiment, stage A is heated indirectly at least in part by a heat pump, for example, heated to 50%.

[0038] In the first stage, the air supply is carried out in a recirculating air manner, particularly in each zone. Preferably, the first stage is a light structure, whereby although each drying zone has side walls and a top covering, it does not require its own lamellae as the drying zones are built directly on the floor of the factory hall. Preferably, the drying zones of the first stage do not have nozzle boxes, which makes the design very simple and inexpensive. The first drying zone of the first stage (for example, the first five drying zones of the first stage) is preferably configured to receive heat from at least one heat pump and / or heating component. Preferably, all drying zones of the first stage or each drying zone of at least the first drying zone are equipped with fans for generating a cross-flow of air, while the hot air generated by the high-temperature heat pump passes longitudinally through the first stage and preferably also through the second stage. At several positions, the drying device is preferably equipped with fans or nozzles and chimneys for discharging the saturated moist air.

[0039] The exhaust gas from the drying process of the first stage A can be advantageously reused by transferring it to a heat exchanger for preheating the drying air of the second stage B.

[0040] When the boards are first dried in a pre-drying stage upstream of the first stage A, then dried in the first stage A, and finally dried in the second stage B, a higher energy efficiency can be achieved with the drying method according to the invention.

[0041] Preferably, the boards are conveyed through stages A and B by conveying means provided respectively for each of stages A, B and / or for each section. Optionally, the conveying means are driven by direct drive motors or are at least partially interconnected via gearboxes.

[0042] The invention provides a drying device for drying boards in a first stage A and a second stage B, each stage being equipped with conveying means for conveying the boards arranged in layers through the drying device, wherein the first stage (A) has at least one zone, wherein the first stage A has a feeding device, a discharging device and a recirculation duct with conveying means and a heating device for recirculating air, as well as a device for supplying supply air and a device for discharging exhaust gas, and wherein the second stage B is configured to receive the boards from the first stage A and has a device for supplying drying air and a device for discharging drying air and a heating device.

[0043] The object of the invention is also to provide a device for implementing the combined method as described above.

[0044] According to the present invention, this task is solved in the following way: The device includes at least a first device and a second device. The first device is used to produce a binder using thermal energy, and the second device is used to dry sheets made of building materials, insulating materials, or binders, where the thermal energy can be transferred from the first device to the second device through a heat pump.

[0045] Advantageous improvements to the device of the present invention can be obtained from the dependent claims.

[0046] Preferably, the first device is a calciner for calcining gypsum or cement, where the second device is used to dry sheets made of building materials, insulating materials, or binders, and the first device is connected to the second device through at least one heat pump.

[0047] It is also advantageous when the calciner is a rotary kiln for drying gypsum and when the second device is a sheet drying device for drying gypsum sheets.

[0048] Preferably, the sheet drying device has a drying zone for drying the sheets in a first stage (A) and a second stage (B), where the first stage (A) has at least one drying zone, where the first stage can be heated in a recirculation mode, and where the second stage (B) is configured to receive the sheets from the first stage (A) and is equipped with means for supplying fresh air.

[0049] In another advantageous embodiment of the present invention, it is provided that the first stage has a plurality of drying zones, which can be heated by a heat pump, at least one additional heat exchanger, or by hot air, which is generated by at least one heater, a heat pump, a wet separator, or hot steam, thermal oil, indirect electric heating, or a low calorific value heat source.

[0050] In another embodiment, it is advantageously provided that at most a single heat pump is provided to recover the heat supplied to the sheets in the second stage.

[0051] In each of the two stages, the sheets are dried at a speed and temperature that enables the sheets to quickly pass through the drying device and efficiently utilize energy.

[0052] This optimizes the use of primary energy and secondary energy. In particular, by utilizing waste heat and the condensation heat of waste gas, low primary energy use is achieved without the need to increase secondary energy consumption through a large mass air circulation.

[0053] In particular, in the second stage, the need for a high conveying capacity for circulating air is avoided, such that the drying device only has low secondary energy consumption.

[0054] Preferably, the housing of the drying device is equipped with a door section in each drying area. Preferably, the drying device, especially in stage B, does not have independent trays but is built on the floor of the factory workshop.

[0055] The following drying device is advantageous: wherein the first stage and the second stages A and B each include at least one section and are equipped with means for circulating air transversely to the conveying direction of the sheet.

[0056] For design reasons, in another advantageous embodiment, the first stage A of the drying device is divided into several sections, and these sections are at least partially equipped with nozzle boxes for lateral air supply in the form of a hot air impact stream.

[0057] Advantageously, means are provided in the second stage B of the drying device for causing the circulating air to flow in a direction opposite to or the same as the sheet conveying direction.

[0058] In another advantageous embodiment of the drying device, the second stage B is provided with a guiding device for guiding the circulating air to flow in a spiral manner, or is provided with at least one exhaust fan combined with at least one recirculation fan. Auxiliary guiding devices in the form of baffles are also provided.

[0059] Preferably, the drying device includes at least one heat exchanger.

[0060] Preferably, a roller conveyor or a conveyor belt is provided as the conveying device for conveying the sheets to be dried in the drying device.

[0061] In stage B, the exhaust gas from stage A contains highly saturated water vapor, and when this exhaust gas is passed through the heat exchanger, it is cooled in the heat exchanger to such an extent that a part of the water vapor condenses. The fresh air heated in this way is conveyed to stage B.

[0062] When the drying air passes through the heat exchanger in a direction opposite to that of the exhaust gas from stage A (countercurrent mode), the cooler drying air meets the cooled exhaust gas. This ensures that as much water vapor contained in the exhaust gas as possible is condensed and further improves the utilization rate of primary energy. By using the condensation heat, the more intensive use of primary energy can significantly save the consumption of primary energy.

[0063] Overall, the drying capacity of stage B is at most half of the drying capacity of stage A.

[0064] Each of stage A and stage B is equipped with a conveying device for conveying the layered plates through the drying device. The drying device can be designed as a roller conveyor drying device or a belt drying device, wherein the conveying device has a plurality of roller conveying devices or conveyor belts stacked one above the other. The spacing between the laminates is 100 mm to 200 mm, preferably 120 mm, especially for the laminates in the rear section. Stage A and stage B preferably have the same number of laminates for holding the plates to be dried; a larger number (e.g., at least twenty laminates) of laminates is desirable, and of course, more can also be provided. A larger number of laminates combined with a smaller spacing between the laminates enables a very compact design of the drying device, thus saving costs. Since the number of laminates in the two stages A and B is preferably the same, there is no need to provide a separate conveying area between the laminates.

[0065] The plate drying device according to the present invention can be constructed in a compact manner; there is no need to provide a base plate for the drying device; on the contrary, it is sufficient to directly place the side walls of the drying device on the floor of the factory building without laying an additional base plate for the drying device.

[0066] In stage B, an additional heating device for an additional transitional load condition can be installed. Description of the Drawings

[0067] The present invention will be explained in more detail below with reference to the embodiments. The drawings show:

[0068] Figure 1 The overall structure of a combined arrangement of a first device designed as a rotary kiln and a second device designed as a drying device for drying building plates is shown,

[0069] Figure 2 The first device is shown in detail,

[0070] Figure 3 The second device is shown in detail, and

[0071] Figure 4 A flow chart for producing gypsum plates is shown. Detailed Description of the Invention

[0072] The drying device 1 ( Figure 1 ) obtains heat energy supply from the calcining furnace 101 having a rotary kiln 100 via a high-temperature heat pump 101.

[0073] The rotary kiln 100 ( Figure 2)It includes a rotary tube 102 which is driven to rotate by a driving gear 104 driven by a motor 103. A calciner 105 generates hot air which is supplied into the interior of the rotary tube 102 through a duct 106a and a chamber 106 located upstream of the rotary tube 102; gypsum or other binders (such as cement) or building materials introduced into the rotary tube 102 in powder form through a rotary valve 107 (which serves as a raw gypsum feeding device) are heated and dehumidified inside. The rotary tube 102 is provided with outlets or inlets 108, 110 arranged, for example, through a rotary joint, through which hot air or flue gas is discharged, or cooling air is supplied. In particular, the flue gas escapes through the chamber 106, a flue gas exhaust fan 106b and a chimney 106c downstream thereof. Cooling air is supplied through the inlet 110; after being heated in the rotary tube 102, the cooling air is fed to the calciner 105 as calcining air via the outlet 108 and a fan 113 and via a fan 113b. Air is supplied to a chimney 113a via an outlet 111 in the chamber 106 via a fan 112.

[0074] The calcined gypsum is directly discharged from the rotary tube 102 through an outlet 109, a rotary valve 115 downstream of the outlet 109 and a conveying screw 115a, or is discharged from the rotary tube 102 through a cooling device or a dust filter 114 and another rotary valve 116 downstream of the rotary tube 102. While discharging the building materials, a large amount of hot air is also discharged from the rotary tube, especially through dust removal fans 117, 118. The fan 118 is connected downstream of a filter 119. The hot exhaust gas is then supplied to a heat pump 120. The gypsum is conveyed from the filter 119 to the conveying screw 115a through a rotary valve 119a.

[0075] The heat pump 120 extracts thermal energy from the hot exhaust gas guided through the fan 118 by a coolant. The cooled exhaust gas is then discharged through a chimney 120a.

[0076] The thermal energy extracted from the heat pump 120 is transferred to a heat exchanger 121 through a coolant and / or a steam turbine via a heating component or the heat pump, and then conveyed from the heat exchanger to a drying device 1.

[0077] For this purpose, the pipeline 120b guides a fluid (such as water) from the heat pump to the heat exchanger 121. The heat exchanger 121 is connected to the coolant circuit via the pipeline 122 and is connected to a compressor (such as the piston compressor 122a), which is used to compress the fluid used as the coolant in the coolant circuit; the coolant is supplied to the heat exchanger 125 via the pipeline 122, and the heat exchanger 125 is a steam generator for generating steam, and the steam is used to heat the plates in the drying device 1. The drying device 1 is thus connected to a steam circuit with steam compression. The coolant circuit with the compressor forms the first heat pump stage, while the steam circuit represents the second heat pump stage.

[0078] A compressor 127 is arranged in the pipeline 126, and steam is supplied to the drying device 1 as a heat transfer medium through the pipeline 126. A condensate discharge device or a condensate separator 129 is arranged in the pipeline 128, and the cooled steam returns to the heat exchanger 125 in the pipeline 128. The cooled hot air returns to the heat exchanger 125 from the drying device 1 through the pipeline 128. A control valve 126a is also arranged in the pipeline 126.

[0079] The drying device 1 ( Figure 3 ) includes two stages A and B for drying the plates, and the plates are supplied to the drying device 1 in the direction of the arrow C. These plates are especially building plates, such as gypsum board plates or gypsum fiber plates.

[0080] Each of the two stages A and B is preferably divided into a plurality of sections 2. This especially applies to stage A, where additional heat exchangers 12 are arranged in the sections 2 of stage A, and each heat exchanger 12 is connected to the pipelines 126 and 128 and is used for heating with steam; alternatively, the coolant from the heat pump can also be used. As an additional device for generating heat in the sections 2 of stage A, calciners 12a are provided in all or part of the sections 2 of stage A, and the calciners 12a can be used redundantly. In this way, a temperature up to 160 °C can be generated within the sections 2 of stage A.

[0081] Preferably, stage A has a pre-drying section 3 on the inlet side. The pre-drying section 3 is supplied with fresh air heated by the heat exchanger 4 via the supply pipeline 6 equipped with a closable baffle 5; the supply of this fresh air is not only used for heating the plates, but also for isolating stage A from other airflows and preventing external air from entering stage A.

[0082] Via the pipe 7 branched from the supply pipe 6, the fresh air heated by the heat exchanger, the wet steam or the coolant is distributed to the individual pipes 9, 10, 11. The fresh air reaches the heating devices 12, 13 and 14 from these pipes, and the heating devices 12, 13 and 14 are arranged, for example, in the ceiling box above the nozzle box. As Figure 1As shown, heating devices or heating components 12 to 14 are respectively assigned to two sections 2 of stage A. It should be understood that other distribution methods can also be carried out in another embodiment. For example, in another embodiment, one heating device is provided for each section. The heating devices 12 to 14 are preferably direct heating devices (such as calciners) or indirect heating devices (such as steam or electric heaters). In or for each section 2, at least one recirculation fan 15 to 18 is provided to generate a cross-flow of hot air as recirculated air in section 2. Optionally, two recirculation fans 15 to 17 are provided for each section 2.

[0083] Stage B is also supplied with heated fresh air through a heat exchanger 4. Pipes 19 to 24 are used for this purpose. Among them, pipes 19, 21 and 23 are respectively provided with control valves 25, 26 and 27.

[0084] At the entrance of section 2, the air flowing into section 2 from pipes 19 to 24 is heated by heating devices 29 to 31. When additional heating energy is required, the heating devices 29 to 31 are started; this is the case when the system is started, and when the heat provided from stage A is still insufficient, and the heat exchanger 4 has not received any hot exhaust gas from stage A or does not have enough hot exhaust gas, these heating devices also need to be started. When the system is shut down and the hot air provided from stage A for entering stage B is insufficient, if the sheets to be dried have a higher moisture content than expected, or when switching between different sheet specifications, this may lead to a lack of thermal energy in stage B. Therefore, the heating devices 29 to 31 are specifically provided for transitional load conditions in stage B.

[0085] It should be understood that according to the length of stage B, a large number of air supply pipelines, especially pipelines for hot air from the heat exchanger 4 or from another heat exchanger, can be provided in order to recover the evaporation enthalpy of the water evaporated from the sheets.

[0086] Similar to the recirculation fans, exhaust fans 32, 33 are distributed along the entire length of stage B, and only exhaust fans 32, 33 are shown as examples. The moist air is discharged from stage B through these fans and chimneys 34, 35. In addition, an exhaust fan 36 is also provided at the end connected to chimney 37.

[0087] Internal heat exchangers can be provided in stage A and stage B, for example, an internal heat exchanger can be provided in the ceiling box above the nozzle box in stage A, or an internal heat exchanger can be provided in a dedicated ceiling box above the conveyor device in stage B.

[0088] The heat exchanger 4 is connected to the section 2 of stage A via the exhaust duct 38 and the central exhaust duct 39. Via the exhaust ducts 38, 39, the warm, moisture-saturated air is supplied to the heat exchanger 4 by means of an exhaust fan 40. In the heat exchanger 4, the air condenses and discharges its moisture in the form of water into the environment via the chimney 42.

[0089] The heat exchanger 4 draws in fresh air by means of a fresh air fan 41. A heating component 43 is provided between the fresh air fan 41 and the heat exchanger to utilize the condensation heat.

[0090] The combined method according to the invention is used for the production of gypsum boards, wherein raw gypsum 400 ( Figure 4 ) is fed into the calciner 101. The calciner 101 produces massive gypsum 401 in the rotary kiln 100, and the massive gypsum 401 is fed into a device 402 for the production of gypsum boards. The device 402 includes a mixer; in the mixer, by adding cardboard 403, starch 404 and additives 405, and with the aid of an adhesive tape and a cutting device, gypsum paper boards 406 are produced, at which time the gypsum paper boards 406 still have a relatively high moisture content. The gypsum paper boards 406 are then fed into the drying device 1.

[0091] On the other hand, the waste heat 407 from the calciner 101 is supplied to a heat pump 408 or a plurality of heat pumps or a heat recovery device. At least one heat pump 408 supplies heat energy 409 to the drying device 1, and the drying device 1 produces dry gypsum paper boards 410. These gypsum paper boards 410 go through steps 412 including trimming, stacking and packaging until marketable gypsum boards 411 are formed.

Claims

1. A combined method includes a method of using thermal energy to produce or process a binder in a first device (100) and a method of drying a board produced using a building material, an insulating material, or a binder in a second device designed as a drying device (1), wherein waste heat generated in the first device is recovered by at least one heat pump and at least part of the waste heat is supplied to the second device, and in the second device, the waste heat is used to dry the board.

2. The combined use method according to claim 1, characterized in that, The heat from the heat pump is conducted to the second device (1) through at least one heat exchanger.

3. The combined use method according to claim 1 or 2, characterized in that, Hot air heats the building material in a rotary kiln (100) and the air around the building material in the rotary kiln in a countercurrent manner, and the heated building material is discharged from the rotary kiln (100) together with the air heated in the rotary kiln. The building material is conveyed out of the rotary kiln (100) through a conveying device, and the heated air is supplied to the at least one heat pump (120).

4. The combined use method according to any one of claims 1 to 3, characterized in that Gypsum or cement clinker is calcined in a calciner, and a board containing the gypsum or the cement clinker is dried in the second device.

5. The combined use method according to claim 4, characterized in that Gypsum board or cement board is produced from gypsum heated in the rotary kiln or cement clinker heated in the calciner during an intermediate process, and the gypsum board or the cement board is dried in the second device.

6. The combined use method according to any one of claims 1 to 5, characterized in that The air heated by the heat pump is supplied to a second device designed as the drying device.

7. The combined use method according to claim 5, characterized in that, The heated air is supplied to at least one front part in the second device with respect to the board conveying direction.

8. The combined use method according to claim 6 or 7, characterized in that, The board passes through a first stage (A) and a second stage (B) in the drying device, wherein both stages (A, B) include laminates, the board is placed on the surfaces formed in each laminate, and the board passes through the drying device in the laminates of the two stages (A, B) respectively. The board is in contact with hot drying air and dried in the first stage (A), and the board is dried with drying air at a lower temperature in the second stage (B). The board is heated by hot air generated by direct heating of a heat exchanger, a heat pump, a wet separator, a calciner or by hot steam, heat transfer oil, indirect electric heating or a low calorific value heat source. At most, a single device is provided for recovering the heat supplied to the board in the second stage.

9. The combination method according to any one of claims 1 to 8, characterized in that, The board is dried by recycled air at least in the first stage.

10. The combined use method according to any one of claims 1 to 9, characterized in that, The board is dried at least substantially by using a nozzle box in the region of the first stage (A).

11. The combination method according to any one of claims 1 to 10, characterized in that, The board is dried in the first stage (A) or the second stage (B) through at least one internal heat exchanger (27) and / or through at least one external heat exchanger (4, 43, 44, 45).

12. The combined use method according to any one of claims 1 to 11, characterized in that, The board is dried by drying air at a temperature of 20 °C to 90 °C in the second stage (B).

13. The combined use method according to any one of claims 1 to 12, characterized in that, The exhaust gas from the first stage (A) is supplied to a heat exchanger (31) for preheating the drying air of the second stage (B).

14. The combination method according to any one of claims 1 to 13, characterized in that, The sheet material is first dried in a pre-drying stage upstream of the first stage (A), then dried in the first stage (A), and finally dried in the second stage (B).

15. An apparatus for implementing the combination method according to any one of claims 1 to 14, characterized in that, The device includes at least a first device and a second device, the first device being for producing a binder using thermal energy, and the second device being for drying sheets produced using building materials or insulating materials or binders, wherein the thermal energy can be transferred from the first device to the second device via a heat pump.

16. The device according to claim 15, characterized in that, The first device is a calciner for drying gypsum or cement, and the second device is for firing sheets produced using building materials or insulating materials or binders, wherein the first device is connected to the second device via at least one heat pump.

17. The device according to claim 16, characterized in that, The calciner is a rotary kiln for drying gypsum, and the second device is a sheet drying device for drying gypsum sheets.

18. The device according to any one of claims 15 to 17, characterized in that, The sheet drying device has a drying zone for drying the sheets in a first stage (A) and a second stage (B), the first stage (A) having at least one drying zone, the first stage being heatable in a recirculation mode, and the second stage (B) being configured to receive the sheets from the first stage (A) and being equipped with means for longitudinal air supply.

19. The device according to any one of claims 15 to 18, characterized in that, The first stage has a plurality of drying zones, the drying zones being heatable by a heat pump, at least one heat exchanger, or by hot air, the hot air being generated by at least one heater, heat pump, wet separator, or hot steam or heat transfer oil or indirect electric heating or low calorific value heat source.

20. The device according to claim 19, characterized in that, At most, a single device is provided for recovering the heat that can be provided to the sheets in the second stage.

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