Calcination system

Abstract

A calcining system comprises a first dry material conveying device, a rotary kiln, a second dry material conveying device, a calcining device, a third dry material conveying device, a cooler, a fourth dry material conveying device and a storage bin. The multifunctional device comprises a first air path, a first fan and a heat exchanger, the heat exchanger is provided with a heat exchange water path and a heat exchange air path, and the first air path passes through the cooler and is communicated with the heat exchange air path; the heat supply device comprises a first water path, a flash tank, a second water path, a third water path and a fourth water path, the first water path passes through the calcinator, an outlet of the first water path is communicated with an inlet of the flash tank, a steam outlet of the flash tank is communicated with an inlet of the second water path, and the second water path passes through the downstream section of the rotary kiln; an outlet of the second water path is communicated with an inlet of the heat exchange water path, a water outlet of the flash tank is communicated with the inlet of the heat exchange water path through the third water path, an outlet of the heat exchange water path is communicated with an inlet of the fourth water path, and the fourth water path passes through the upstream section of the rotary kiln. The calcining system is lower in energy consumption.

Description

Technical Field

[0001] This invention relates to the field of gypsum board production technology, and more specifically, to a calcination system. Background Technology

[0002] In the calcination process of gypsum, coal-fired furnaces are becoming increasingly rare due to stricter environmental regulations. One alternative is to use natural gas as a heat source, but this method has higher calcination costs. Another option is to use high-temperature steam as a heat source, which has lower calcination costs and is more widely used. For the technology using high-temperature steam as a heat source, how to better reduce energy consumption and improve energy utilization efficiency has always been a technical problem that those skilled in the art have been working to solve. Summary of the Invention

[0003] This application provides a calcination system, including: a first dry material conveying device, a rotary kiln, a second dry material conveying device, a calciner, a third dry material conveying device, a cooler, a fourth dry material conveying device, and a storage bin. The first dry material conveying device is configured to supply material to the inlet of the rotary kiln; the second dry material conveying device is configured to receive material from the outlet of the rotary kiln and supply material to the inlet of the calciner; the third dry material conveying device is configured to receive material from the outlet of the calciner and supply material to the inlet of the cooler; and the fourth dry material conveying device is configured to receive material from the outlet of the cooler and supply material to the storage bin. A multi-functional device includes a first air duct, a first fan, and a heat exchanger. The heat exchanger has a hot water exchange duct and a hot air exchange duct. The first air path passes through the cooler and is connected to the heat exchange air path. The first fan is configured to form an air jet blowing from the first air path to the heat exchange air path. The heating device includes a first water path, a flash tank, a second water path, a third water path, and a fourth water path. The first water path passes through the calciner. The outlet of the first water path is connected to the inlet of the flash tank. The steam outlet of the flash tank is connected to the inlet of the second water path. The second water path passes through the downstream section of the rotary kiln. The outlet of the second water path is connected to the inlet of the heat exchange water path. The outlet of the flash tank is connected to the inlet of the heat exchange water path through the third water path. The outlet of the heat exchange water path is connected to the inlet of the fourth water path. The fourth water path passes through the upstream section of the rotary kiln.

[0004] In some exemplary embodiments, the heating device further includes a condensate tank, wherein the outlet of the first water path is connected to the inlet of the condensate tank, and the outlet of the condensate tank is connected to the inlet of the flash tank.

[0005] In some exemplary embodiments, the first dry material conveying device includes a feeder, and the multifunctional device further includes a first dehumidifying air path, the inlet of the first dehumidifying air path being connected to the outlet of the heat exchange air path and the outlet being connected to the interior of the feeder, and the outlet of the feeder being sealed and connected to the inlet of the rotary kiln.

[0006] In some exemplary embodiments, the second dry material conveying device includes a first conveyor, a second conveyor, and a first elevator. The inlet of the first conveyor is configured to receive material from the outlet of the rotary kiln and to supply material to the inlet of the calciner and the inlet of the second conveyor. The outlet of the second conveyor is configured to supply material to the inlet of the first elevator, and the outlet of the first elevator is configured to supply material to the inlet of the feeder. The multifunctional device also includes a second dehumidifying air passage, the inlet of which is connected to the outlet of the heat exchange air passage, and the outlet of which is connected to the interior of the second conveyor.

[0007] In some exemplary embodiments, the calcination system further includes a dust collection device, configured at least to collect dust from the rotary kiln, the second conveyor, the calciner, and the cooler.

[0008] In some exemplary embodiments, the second dry material conveying device further includes a first rotary valve, a second elevator, a pneumatic three-way valve, an intermediate silo, a rotary screen, a third conveyor, and a waste silo. The first outlet of the first conveyor is configured to supply material to the inlet of the second elevator; the second outlet of the first conveyor is configured to supply material to the inlet of the second conveyor via the first rotary valve; the outlet of the second elevator is configured to supply material to the inlet of the pneumatic three-way valve; the first outlet of the pneumatic three-way valve is configured to supply material to the inlet of the intermediate silo; the outlet of the intermediate silo is configured to supply material to the inlet of the second conveyor via the second rotary valve; the second outlet of the pneumatic three-way valve is configured to supply material to the inlet of the rotary screen; the outlet of the rotary screen is configured to supply material to the inlet of the calciner via the third conveyor; and the waste outlet of the rotary screen is configured to discharge waste into the waste silo.

[0009] In some exemplary embodiments, the first dry material conveying device further includes a desulfurized gypsum hopper, a belt scale, a first belt conveyor equipped with an iron remover, a roller screen, a second belt conveyor, and an airlock unloader arranged in sequence, wherein the airlock unloader is configured to feed material to the inlet of the feeder.

[0010] In some exemplary embodiments, the calcination system further includes: a fluidizing air supply device, the fluidizing air supply device including a second fan, a second air path and a plurality of fluidizing air paths, the calciner having a plurality of calcination chambers connected in sequence, the second air path passing through the cooler, the inlets of the plurality of fluidizing air paths being connected to the outlets of the second air paths, the outlets of the plurality of fluidizing air paths being connected to the interiors of the plurality of calcination chambers one-to-one, and the second fan being configured to form an air jet blowing from the second air path to the plurality of fluidizing air paths.

[0011] In some exemplary embodiments, the cooler has a high-temperature cooling zone, a medium-temperature cooling zone, and a low-temperature cooling zone; the second air path is a second air duct passing through the high-temperature cooling zone; and the first air path is a first air duct passing through the medium-temperature cooling zone. The calcination system further includes: a first cooling device, which includes a third fan and a third air path, wherein the third air path is a third air duct passing through the low-temperature cooling zone, and the third fan is connected to the third air duct; and a second cooling device, which includes a fourth fan, which is connected to the interior of the cooler and configured to cause fluidization of the material within the cooler.

[0012] In some exemplary embodiments, the third dry material conveying device includes a fourth conveyor and a third elevator, wherein the fourth conveyor is configured to receive material from the outlet of the calciner and supply material to the inlet of the third elevator, and the outlet of the third elevator is configured to supply material to the inlet of the cooler.

[0013] In some exemplary embodiments, the fourth dry material conveying device includes a third rotary valve, a ball mill, a fifth conveyor, and a fourth elevator. The outlet of the cooler is configured to feed material to the inlet of the ball mill through the third rotary valve. The fifth conveyor is configured to receive material from the outlet of the ball mill and feed material to the inlet of the fourth elevator. The outlet of the fourth elevator is configured to feed material to the storage bin.

[0014] The calcination system proposed in this embodiment of the invention has the following steps: First air path passes through a cooler. Dry air is blown through the first air path into the heat exchange air path. As the dry air passes through the cooler (i.e., the portion of the first air path that passes through the cooler), it exchanges heat with the cooler, causing its temperature to rise. High-temperature steam enters the first water path from the inlet. During its passage through the calciner, it calcines the material inside to remove some of the water of crystallization. The high-temperature steam then forms high-temperature condensate, which enters a flash tank. In the flash tank, flash evaporation occurs, forming medium-temperature flash steam and medium-temperature condensate. The medium-temperature flash steam enters the second water path from the outlet of the flash tank. As it passes through the downstream section of the rotary kiln (i.e., the portion of the second water path that passes through the downstream section of the rotary kiln), it heats the material in the downstream section of the rotary kiln to remove free water in two steps. Then, the medium-temperature condensate formed by the flash steam flows to the heat exchanger path. The medium-temperature condensate in the flash tank flows from the outlet of the flash tank to the heat exchanger path through the third water path. The medium-temperature condensate passing through the heat exchanger path exchanges heat with the low-temperature air passing through the heat exchanger air path, causing the temperature of the low-temperature air passing through the heat exchanger air path to rise and form medium-temperature air. The temperature of the medium-temperature condensate passing through the heat exchanger path decreases and forms low-temperature heat exchanger water (the temperature of the low-temperature heat exchanger water is still higher than the temperature of the medium-temperature air). The low-temperature heat exchanger water passes through the fourth water path and heats the material in the upstream section of the rotary kiln (i.e., the part of the high-temperature heat exchanger water passing through the fourth water path and the upstream section of the rotary kiln) to initially remove free water. This scheme not only utilizes the latent heat of steam but also the sensible heat of the high-temperature condensate formed after the steam releases heat and condenses. Therefore, the energy consumption of this calcination system is lower and the energy utilization rate is higher.

[0015] Furthermore, the medium-temperature air is introduced into the feeder through the first dehumidification air passage. Since the outlet of the feeder is sealed and connected to the inlet of the rotary kiln, the medium-temperature air introduced into the feeder will also enter the rotary kiln. The medium-temperature air dries the wet material in the feeder and carries away the moisture evaporated from the wet material. The air entering the rotary kiln from the feeder will carry away the moisture evaporated from the material in the rotary kiln.

[0016] Furthermore, medium-temperature air is introduced into the interior of the second conveyor through the second dehumidification air passage to dry the material in the second conveyor and remove the moisture evaporated from the material in the second conveyor.

[0017] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application can be realized and obtained by means of the embodiments described in the description and the accompanying drawings. Attached Figure Description

[0018] The accompanying drawings are used to provide an understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0019] Figure 1 Schematic block diagrams of the calcination system provided in some embodiments of this application; Figures 2 to 4 for Figure 1 A schematic block diagram of a partial structure of the calcination system is shown. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

[0021] The calcination system provided in the embodiments of this application, such as Figures 1 to 4 As shown, the system includes: a first dry material conveying device, a rotary kiln 109, a second dry material conveying device, a calciner 121, a third dry material conveying device, a cooler 127, a fourth dry material conveying device, and a storage bin 146. The first dry material conveying device is configured to feed material into the inlet of the rotary kiln 109; the second dry material conveying device is configured to receive material from the outlet of the rotary kiln 109 and feed material into the inlet of the calciner 121; the third dry material conveying device is configured to receive material from the outlet of the calciner 121 and feed material into the inlet of the cooler 127; and the fourth dry material conveying device is configured to receive material from the outlet of the cooler 127 and feed material into the storage bin 146. A multi-functional device is also included, comprising a first air passage 210, a first fan 133, and a heat exchanger 135. The heat exchanger 135 has a hot water exchange passage and a hot air exchange passage. The first air passage 210 passes through… A cooler 127 is connected to a heat exchange air path. A first fan 133 is configured to form an air stream blowing from the first air path 210 to the heat exchange air path. A heating device is provided, which includes a first water path 220, a flash tank 148, a second water path 230, a third water path 240, and a fourth water path 250. The first water path 220 passes through a calciner 121. The outlet of the first water path 220 is connected to the inlet of the flash tank 148. The steam outlet of the flash tank 148 is connected to the inlet of the second water path 230. The second water path 230 passes through the downstream section of the rotary kiln 109. The outlet of the second water path 230 is connected to the inlet of the heat exchange water path. The outlet of the flash tank 148 is connected to the inlet of the heat exchange water path through the third water path 240. The outlet of the heat exchange water path is connected to the inlet of the fourth water path 250. The fourth water path 250 passes through the upstream section of the rotary kiln 109.

[0022] In this calcination system, the first air path 210 passes through the cooler 127. Dry air (such as ambient air) is blown through the first air path 210 into the heat exchange air path. As the dry air passes through the cooler 127 (i.e., the portion of the air passing through the first air path 210 that passes through the cooler 127), the dry air undergoes heat exchange with the cooler 127, causing its temperature to rise. High-temperature water vapor is introduced into the first water path 220 through its inlet, and as it passes through the calciner 121, it oxidizes the material inside the calciner 121. Calcination is performed to remove some of the water of crystallization. The high-temperature steam then forms high-temperature condensate which enters flash tank 148. Flash evaporation occurs in flash tank 148, forming medium-temperature flash steam and medium-temperature condensate. The medium-temperature flash steam enters the second water passage 230 from the steam outlet of flash tank 148. During its passage through the downstream section of rotary kiln 109 (i.e., the portion of the flash steam passing through the second water passage 230 that passes through the downstream section of rotary kiln 109), the material in the downstream section of rotary kiln 109 is heated to remove free water in two steps, followed by flash evaporation. The medium-temperature condensate formed by water vapor flows to the heat exchanger circuit. The medium-temperature condensate in flash tank 148 flows from its outlet through the third water circuit 240 to the heat exchanger circuit. The medium-temperature condensate in the heat exchanger circuit exchanges heat with the low-temperature air passing through the heat exchanger air circuit, causing the temperature of the low-temperature air to rise and become medium-temperature air. Meanwhile, the temperature of the medium-temperature condensate in the heat exchanger circuit decreases, forming low-temperature heat exchanger water (the temperature of the low-temperature heat exchanger water is still higher than the temperature of the medium-temperature air). This low-temperature heat exchanger water then flows through the fourth water circuit 250... During the process of passing through the upstream section of rotary kiln 109 (i.e., the part of the high-temperature hot water passing through the fourth water channel 250 that passes through the upstream section of rotary kiln 109), the material in the upstream section of rotary kiln 109 is heated to initially remove free water (i.e., the material in rotary kiln 109 is first dehumidified by initially removing free water, and then dehumidified by removing free water in two steps). This scheme not only utilizes the latent heat of water vapor, but also the sensible heat of the high-temperature condensate formed after the water vapor releases heat and condenses. Therefore, the energy consumption of this calcination system is lower and the energy utilization rate is higher.

[0023] Among them, the calciner 121 is a boiling calciner that uses steam as a heat source. The boiling calciner is used to calcine materials. The cooler 127 is a boiling cooler used to cool the calcined materials. The storage bin 146 is a calcined gypsum bin. The high-temperature steam entering the first water passage 220 comes from the gas distribution cylinder and flows back to the power plant through the low-temperature hot water in the fourth water passage 250.

[0024] In some embodiments, such as Figure 1 and Figure 4As shown, the first fan 133 is located between the first air passage 210 and the heat exchange air passage. The multi-functional device also includes a makeup air passage 260 equipped with an electric butterfly valve 134. The inlet of the makeup air passage 260 is connected to the outside, and the outlet is connected to the inlet of the first fan 133. The makeup air passage 260 is used to adjust the opening degree to make up for the air as needed.

[0025] In some examples, such as Figure 3 As shown, the heating device also includes: a condensate tank 147, the outlet of the first water passage 220 is connected to the inlet of the condensate tank 147, the outlet of the condensate tank 147 is connected to the inlet of the flash tank 148, the condensate tank 147 is used to store the condensate formed by high-temperature water vapor after passing through the first water passage 220 and to supply the stored condensate to the flash tank 148.

[0026] In some examples, such as Figure 2 and Figure 3 As shown, the first dry material conveying device includes a feeder 108, and the multi-functional device also includes a first dehumidifying air passage 270. The inlet of the first dehumidifying air passage 270 is connected to the outlet of the heat exchange air passage, and the outlet is connected to the interior of the feeder 108. The outlet of the feeder 108 is sealed and connected to the inlet of the rotary kiln 109.

[0027] Medium-temperature air is introduced into the feeder 108 through the first dehumidification air passage 270. Since the outlet of the feeder 108 is sealed and connected to the inlet of the rotary kiln 109, the medium-temperature air introduced into the feeder 108 will also enter the rotary kiln 109. The medium-temperature air dries the wet material in the feeder 108 and carries away the moisture evaporated from the wet material. The air entering the rotary kiln 109 from the feeder 108 will carry away the moisture evaporated from the material in the rotary kiln 109.

[0028] Among them, feeder 108 is a twin-screw feeder.

[0029] In some examples, such as Figure 3 As shown, the second dry material conveying device includes a first conveyor 110, a second conveyor 112, and a first elevator 113. The inlet of the first conveyor 110 is configured to receive material from the outlet of the rotary kiln 109 and supply material to the inlet of the calciner 121 and the inlet of the second conveyor 112. The outlet of the second conveyor 112 is configured to supply material to the inlet of the first elevator 113, and the outlet of the first elevator 113 is configured to supply material to the inlet of the feeder 108. The multi-functional device also includes a second dehumidifying air passage 280. The inlet of the second dehumidifying air passage 280 is connected to the outlet of the heat exchange air passage, and the outlet is connected to the interior of the second conveyor 112. Medium-temperature air is introduced into the interior of the second conveyor 112 through the second dehumidifying air passage 280 to carry away the moisture evaporated from the material inside the second conveyor 112.

[0030] Among them, the first conveyor 110 and the second conveyor 112 are both screw conveyors, and the first elevator 113 is a bucket elevator.

[0031] In some embodiments, such as Figure 3 As shown, the second dry material conveying device also includes a first rotary valve 111, a second elevator 114, a pneumatic three-way valve 115, an intermediate silo 116, a second rotary valve 117, a rotary screen 119, a third conveyor 120, and a waste bin 290. The first outlet of the first conveyor 110 is configured to feed material to the inlet of the second elevator 114, and the second outlet of the first conveyor 110 is configured to feed material to the inlet of the second conveyor 112 through the first rotary valve 111 (the rotary valve can precisely adjust the discharge amount). The second elevator 114... The outlet is configured to supply material to the inlet of pneumatic three-way valve 115. The first outlet of pneumatic three-way valve 115 is configured to supply material to the inlet of intermediate silo 116. The outlet of intermediate silo 116 is configured to supply material to the inlet of second conveyor 112 via second rotary valve 117. The second outlet of pneumatic three-way valve 115 is configured to supply material to the inlet of rotary screen 119. The outlet of rotary screen 119 is configured to supply material to the inlet of calciner 121 via third conveyor 120. The waste outlet of rotary screen 119 is configured to discharge waste into waste silo 290. First rotary valve 111 is used for airlock unloading. Frequency conversion control controls the amount of material supplied by first conveyor 110 to second conveyor 112, thereby controlling the amount of dry material returned by first elevator 113 to feeder 108. The intermediate silo 116 is used to store dry materials, ensuring that during startup and stable operation, dry materials are sequentially supplied to the feeder 108 via the second conveyor 112 and the first elevator 113. A pneumatic three-way valve 115 is used for material distribution. A rotary screen 119 is used to screen the dry materials and separate impurities.

[0032] Among them, the second elevator 114 is a bucket elevator, and the third conveyor 120 is a screw conveyor.

[0033] In some embodiments, such as Figure 1As shown, the first dry material conveying device also includes, in sequence, a desulfurized gypsum hopper 101, a belt scale 102, a first belt conveyor 104 equipped with an iron remover 103, a roller screen 105, a second belt conveyor 106, and an airlock unloader 107. The airlock unloader 107 is configured to receive material from the second belt conveyor 106 and feed material to the inlet of the feeder 108. The desulfurized gypsum hopper 101 is used to store desulfurized gypsum and provide raw materials (wet material) for the system. The belt scale 102 is used to accurately measure the amount of desulfurized gypsum (wet material) fed into the system. The iron remover 103 is used to remove iron impurities. The first belt conveyor 104 is used to convey the raw material. The roller screen 105 is used to screen out large impurities in the wet material. The second belt conveyor 106 is used to convey the raw material. The airlock unloader 107 is used to receive material from the second belt conveyor 106, feed material to the inlet of the feeder 108, and ensure that the feeder 108 is sealed. The feeder 108 is used to mix materials so that the wet material from the desulfurized gypsum hopper 101 and the dry material from the second conveyor 112 are fully mixed, and the dry material is fed into the feeder 108 from upstream of the wet material to prevent the wet material from corroding the feeder 108.

[0034] In some examples, such as Figure 3 and Figure 4 As shown, the calcination system also includes a fluidizing air supply device, which includes a second fan 128, a second air path 300, and multiple fluidizing air paths 310. The calciner 121 has multiple calcination chambers connected in sequence. The second air path 300 passes through a cooler 127. The inlets of the multiple fluidizing air paths 310 are connected to the outlets of the second air path 300, and the outlets of the multiple fluidizing air paths 310 are connected to the interiors of the multiple calcination chambers one by one. The second fan 128 is configured to form an air jet that blows from the second air path 300 to the multiple fluidizing air paths 310. When the second blower 128 operates, dry air (such as ambient air) passes through the second air passage 300. The dry air's temperature rises as it passes through the cooler 127 (i.e., the portion of the dry air passing through the second air passage 300 that passes through the cooler 127). Then, it enters the multiple calciners of the calciner 121 through multiple fluidizing air passages 310, causing the material in each calciner to fluidize. The fluidizing air jets utilize the heat lost from the material in the cooler 127, further improving the system's energy efficiency. The second blower 128 is a Roots blower.

[0035] In some embodiments, such as Figure 4As shown, the cooler 127 has a high-temperature cooling zone 320, a medium-temperature cooling zone 330, and a low-temperature cooling zone 340. The second air passage 300 is a second air duct passing through the high-temperature cooling zone 320, and the first air passage 210 is a first air duct passing through the medium-temperature cooling zone 330. The calcination system also includes: a first cooling device, which includes a third fan 138 and a third air passage 350, where the third air passage 350 is a third air duct passing through the low-temperature cooling zone 340, and the third fan 138 is connected to the third air duct; and a second cooling device, which includes a fourth fan 139, which is connected to the interior of the cooler 127. When the third fan 138 operates, dry air (such as ambient air) passes through the third air passage 350 and exchanges heat with the dry material located in the low-temperature cooling zone 340 within the cooler 127, thereby cooling the dry material in the low-temperature cooling zone 340 within the cooler 127. The fourth blower 139 is a Roots blower. When the fourth blower 139 operates, it introduces airflow (ambient air) into the bottom of the cooler 127, causing the dry material inside the cooler 127 to fluidize and cool down. Specifically, the temperature of the dry material in the high-temperature cooling zone 320 is greater than the temperature of the dry material in the medium-temperature cooling zone 330, which is greater than the temperature of the dry material in the low-temperature cooling zone 340.

[0036] In some examples, such as Figure 3 and Figure 4 As shown, the third dry material conveying device includes a fourth rotary valve 124, a fourth conveyor 125, and a third elevator 126. The outlet of the calciner 121 is sealed to the inlet of the fourth conveyor 125 via the fourth rotary valve 124. The outlet of the fourth conveyor 125 is configured to feed material to the inlet of the third elevator 126, and the outlet of the third elevator 126 is configured to feed material to the inlet of the cooler 127. The fourth conveyor 125 is a screw conveyor, and the third elevator 126 is a bucket elevator.

[0037] In some examples, such as Figure 4 As shown, the fourth dry material conveying device includes a third rotary valve 141, a ball mill 142, a fifth conveyor 143, and a fourth elevator 145. The outlet of the cooler 127 is configured to feed material to the inlet of the ball mill 142 through the third rotary valve 141. The fifth conveyor 143 is configured to receive material from the outlet of the ball mill 142 and feed material to the inlet of the fourth elevator 145. The outlet of the fourth elevator 145 is configured to feed material to the storage bin 146. The ball mill 142 is used to grind the modified and calcined dry material (the dry material is gypsum powder), and the third rotary valve 141 is used to achieve sealed unloading. The fifth conveyor 143 is a screw conveyor, and the fourth elevator 145 is a bucket elevator.

[0038] In some examples, such as Figures 2 to 4As shown, the calcination system also includes: a first dust collection device 144; the dust outlets of the fourth conveyor 125, the third elevator 126, the cooler 127, the ball mill 142, the fifth conveyor 143, and the fourth elevator 145 are all connected to the dust collection port of the first dust collection device 144; the discharge port of the first dust collection device 144 is connected to the inlet of the fifth conveyor 143; and the exhaust port of the first dust collection device 144 is open to the outside; and a second dust collection device... The dust outlets of the first conveyor 110, the second conveyor 112, the first elevator 113, the rotary kiln 109, the intermediate silo 116, the second elevator 114, the rotary screen 119, and the calciner 121 are all connected to the dust collection port of the second dust collection device 118. The discharge port of the second dust collection device 118 is connected to the inlet of the second conveyor 112, and the exhaust port of the second dust collection device 118 is connected to the outside.

[0039] In some embodiments, such as Figure 2 and Figure 3 As shown, the first dehumidifying air passage 270, the second dehumidifying air passage 280, and each fluidizing air passage 310 are equipped with an electric butterfly valve for controlling the flow rate. The electric butterfly valve of the fluidizing air passage 310 is used to control the stable fluidization movement of the material in the calciner 121. Electric butterfly valves for controlling the flow rate are also provided between the dust outlet of the calciner 121 and the dust collection port of the second dust collection device 118, between the dust outlet of the rotary kiln 109 and the dust collection port of the second dust collection device 118, and between the dust outlet of the cooler 127 and the dust collection port of the first dust collection device 144, so that the top of the calciner 121, the top of the rotary kiln 109, and the top of the cooler 127 are all in a slightly negative pressure state.

[0040] The calcination system employs a two-step calcination process. The desulfurized gypsum raw material (wet material), precisely measured by the belt scale 102, is first dried in the rotary kiln 109 to remove free water, completing the first step of calcination. Then, some of the crystal water is removed in the calciner 121, completing the second step of calcination. In this process, steam first fully heats the material in the boiling calciner 121 (a two-step calcination process). The resulting high-temperature condensate first enters the condensate tank 147, and then enters the flash tank 148 for flash evaporation to form medium-temperature flash steam and medium-temperature condensate. The medium-temperature flash steam enters the downstream section of the rotary kiln 109 to heat the material and form medium-temperature condensate. The medium-temperature condensate formed by the flash steam and the medium-temperature condensate in the flash tank 148 pass through the heat exchanger 135 to form low-temperature condensate. The low-temperature condensate enters the upstream section of the rotary kiln 109 to heat the material. This scheme utilizes the energy of high-temperature steam in a stepped manner, making full use of its heat and minimizing the temperature of the discharged condensate.

[0041] To recover the heat from the calcined material (dry material) and ensure the cooling quality of the material (dry material), this process employs a fluidized bed cooler for multi-stage heat exchange. Specifically: the high-temperature cooling zone 320 is used to preheat the Roots air (the Roots air is the air stream within the second air path 300), which is then blown into the calciner 121 as a fluidizing air stream; the medium-temperature cooling zone 330 is used to preheat the return air (the return air is the air stream within the first air path 210), which is heated by the heat exchanger 135 and then blown into the feeder 108, rotary kiln 109, and second conveyor 112 for drying and dehumidification; the low-temperature cooling zone 340 is cooled by the third fan 138 and the third air path 350, ensuring the cooling quality of the material in the cooling zone 320. The material cooled by the cooler 127 is then ground by the ball mill 142 and transported to the storage silo 146 (i.e., the calcined gypsum silo) for storage.

[0042] In summary, the calcination system proposed in this embodiment of the invention involves a first air path passing through a cooler. Dry air is blown through the first air path into the heat exchange air path. As the dry air passes through the cooler (i.e., the portion of the first air path that passes through the cooler), its temperature rises due to heat exchange with the cooler. High-temperature steam enters the first water path from the inlet and calcines the material within the calciner to remove some of the crystal water. The high-temperature condensate formed by the steam then enters a flash tank, where flash evaporation forms medium-temperature flash steam and medium-temperature condensate. The medium-temperature flash steam enters the second water path from the outlet of the flash tank. As it passes through the downstream section of the rotary kiln (i.e., the portion of the flash steam passing through the second water path that passes through the downstream section of the rotary kiln), it heats the material in the downstream section of the rotary kiln to remove free crystals in two steps. Water, then the medium-temperature condensate formed by flash steam flows to the heat exchanger path. The medium-temperature condensate in the flash tank flows from the outlet of the flash tank to the heat exchanger path through the third water path. The medium-temperature condensate passing through the heat exchanger path exchanges heat with the low-temperature air passing through the heat exchanger path, causing the temperature of the low-temperature air passing through the heat exchanger path to rise to medium-temperature air, while the temperature of the medium-temperature condensate passing through the heat exchanger path decreases to form low-temperature heat exchanger water (the temperature of the low-temperature heat exchanger water is still higher than the temperature of the medium-temperature air). The low-temperature heat exchanger water passes through the fourth water path and, during its passage through the upstream section of the rotary kiln (i.e., the part of the high-temperature heat exchanger water that passes through the fourth water path and then through the upstream section of the rotary kiln), heats the material in the upstream section of the rotary kiln to initially remove free water. This scheme not only utilizes the latent heat of steam but also the sensible heat of the high-temperature condensate formed after the steam releases heat and condenses. Therefore, this calcination system has lower energy consumption and higher energy utilization rate.

[0043] Furthermore, the medium-temperature air is introduced into the feeder through the first dehumidification air passage. Since the outlet of the feeder is sealed and connected to the inlet of the rotary kiln, the medium-temperature air introduced into the feeder will also enter the rotary kiln. The medium-temperature air dries the wet material in the feeder and carries away the moisture evaporated from the wet material. The air entering the rotary kiln from the feeder will carry away the moisture evaporated from the material in the rotary kiln.

[0044] Furthermore, medium-temperature air is introduced into the interior of the second conveyor through the second dehumidification air passage to dry the material in the second conveyor and remove the moisture evaporated from the material in the second conveyor.

[0045] In the description of this invention, it should be noted that the terms "upper", "lower", "one side", "the other side", "one end", "the other end", "side", "opposite", "four corners", "periphery", "'mouth' structure", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the "invention" and simplifying the description, and do not indicate or imply that the structure referred to has a specific orientation, or is constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the invention.

[0046] In the description of the embodiments of the present invention, unless otherwise expressly specified and limited, the terms "connection," "direct connection," "indirect connection," "fixed connection," "installation," and "assembly" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. The terms "installation," "connection," and "fixed connection" can refer to a direct connection or an indirect connection through an intermediate medium, or they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0047] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and changes to the form and details of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection of this invention shall still be defined by the appended claims.

Claims

1. A calcination system, characterized in that, include: The system comprises a first dry material conveying device, a rotary kiln, a second dry material conveying device, a calciner, a third dry material conveying device, a cooler, a fourth dry material conveying device, and a storage bin. The first dry material conveying device is configured to supply material to the inlet of the rotary kiln. The second dry material conveying device is configured to receive material from the outlet of the rotary kiln and supply material to the inlet of the calciner. The third dry material conveying device is configured to receive material from the outlet of the calciner and supply material to the inlet of the cooler. The fourth dry material conveying device is configured to receive material from the outlet of the cooler and supply material to the storage bin. A multifunctional device includes a first air path, a first fan, and a heat exchanger. The heat exchanger has a hot water path and a hot air path. The first air path passes through the cooler and is connected to the hot air path. The first fan is configured to form an air jet blown from the first air path to the hot air path. The heating device includes a first water path, a flash tank, a second water path, a third water path, and a fourth water path. The first water path passes through the calciner, and its outlet is connected to the inlet of the flash tank. The steam outlet of the flash tank is connected to the inlet of the second water path. The second water path passes through the downstream section of the rotary kiln, and its outlet is connected to the inlet of the heat exchanger. The outlet of the flash tank is connected to the inlet of the heat exchanger via the third water path, and the outlet of the heat exchanger is connected to the inlet of the fourth water path. The fourth water path passes through the upstream section of the rotary kiln.

2. The calcination system according to claim 1, characterized in that, The heating device also includes: A condensate tank is provided, with the outlet of the first water passage connected to the inlet of the condensate tank, and the outlet of the condensate tank connected to the inlet of the flash tank.

3. The calcination system according to claim 1, characterized in that, The first dry material conveying device includes a feeder, and the multifunctional device further includes a first dehumidifying air path. The inlet of the first dehumidifying air path is connected to the outlet of the heat exchange air path, and the outlet is connected to the interior of the feeder. The outlet of the feeder is sealed and connected to the inlet of the rotary kiln.

4. The calcination system according to claim 3, characterized in that, The second dry material conveying device includes a first conveyor, a second conveyor, and a first elevator. The inlet of the first conveyor is configured to receive material from the outlet of the rotary kiln and to supply material to the inlet of the calciner and the inlet of the second conveyor. The outlet of the second conveyor is configured to supply material to the inlet of the first elevator, and the outlet of the first elevator is configured to supply material to the inlet of the feeder. The multifunctional device also includes a second dehumidifying air duct. The inlet of the second dehumidifying air duct is connected to the outlet of the heat exchange air duct, and the outlet is connected to the interior of the second conveyor.

5. The calcination system according to claim 4, characterized in that, Also includes: The dust collection device is configured to collect dust from the rotary kiln, the second conveyor, the calciner, and the cooler.

6. The calcination system according to claim 4, characterized in that, The second dry material conveying device further includes a first rotary valve, a second elevator, a pneumatic three-way valve, an intermediate silo, a rotary screen, a third conveyor, and a waste silo. The first outlet of the first conveyor is configured to supply material to the inlet of the second elevator. The second outlet of the first conveyor is configured to supply material to the inlet of the second conveyor via the first rotary valve. The outlet of the second elevator is configured to supply material to the inlet of the pneumatic three-way valve. The first outlet of the pneumatic three-way valve is configured to supply material to the inlet of the intermediate silo. The outlet of the intermediate silo is configured to supply material to the inlet of the second conveyor via the second rotary valve. The second outlet of the pneumatic three-way valve is configured to supply material to the inlet of the rotary screen. The outlet of the rotary screen is configured to supply material to the inlet of the calciner via the third conveyor. The waste outlet of the rotary screen is configured to discharge waste into the waste silo.

7. The calcination system according to claim 3, characterized in that, The first dry material conveying device also includes a desulfurized gypsum hopper, a belt scale, a first belt conveyor equipped with an iron remover, a roller screen, a second belt conveyor, and an airlock unloader arranged in sequence. The airlock unloader is configured to supply material to the inlet of the feeder.

8. The calcination system according to any one of claims 1 to 7, characterized in that, Also includes: A fluidizing air supply device includes a second fan, a second air path, and multiple fluidizing air paths. The calciner has multiple calcination chambers connected in sequence. The second air path passes through the cooler. The inlets of the multiple fluidizing air paths are connected to the outlets of the second air paths. The outlets of the multiple fluidizing air paths are connected to the interiors of the multiple calcination chambers one by one. The second fan is configured to form an air jet that blows from the second air path to the multiple fluidizing air paths.

9. The calcination system according to claim 8, characterized in that, The cooler has a high-temperature cooling zone, a medium-temperature cooling zone and a low-temperature cooling zone. The second air path is a second air duct that passes through the high-temperature cooling zone, and the first air path is a first air duct that passes through the medium-temperature cooling zone. The calcination system also includes: A first cooling device, comprising a third fan and a third air duct, wherein the third air duct is a third air pipe passing through the low-temperature cooling zone, and the third fan is connected to the third air duct; and The second cooling device includes a fourth fan, which is connected to the interior of the cooler and is configured to cause the material inside the cooler to undergo fluidization.

10. The calcination system according to any one of claims 1 to 7, characterized in that, The third dry material conveying device includes a fourth conveyor and a third elevator. The fourth conveyor is configured to receive material from the outlet of the calciner and supply material to the inlet of the third elevator. The outlet of the third elevator is configured to supply material to the inlet of the cooler.

11. The calcination system according to any one of claims 1 to 7, characterized in that, The fourth dry material conveying device includes a third rotary valve, a ball mill, a fifth conveyor, and a fourth elevator. The outlet of the cooler is configured to supply material to the inlet of the ball mill through the third rotary valve. The fifth conveyor is configured to receive material from the outlet of the ball mill and supply material to the inlet of the fourth elevator. The outlet of the fourth elevator is configured to supply material to the storage bin.

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