JPH0238347A - Apparatus for calcining gypsum - Google Patents

Abstract

PURPOSE:To enable production of a high-quality product at a low cost with good productivity in simple operation procedures by calcining raw material gypsum using the subject apparatus consisting of a specific constitution. CONSTITUTION:The subject apparatus equipped with a calcining chamber 1, having plural fluidizing furnaces 2, divided with partition plates 7 and provided side by side, a diffusing board 4 for separating each fluidizing furnace 2 into a gas feeding chamber 3 and a fluidizing chamber and uniformly dispersing the flow of a gas fed from the gas feeding chamber 3 to the fluidizing chamber; a gas feed pipe 9 for feeding calcining gas to each gas feeding chamber 3, a gas discharge pipe 8 for discharging gases from the calcining chamber 1, a raw material feeding chute 5 for feeding a raw material to the fluidizing furnace 2 and a discharging chute 8 for discharging calcined substances from the calcining chamber 1. In the above-mentioned apparatus, a raw material gypsum is fed from the raw material feeding chute 5 into the fluidizing furnace 2 in the first stage and converted into a fluidized state of the floated raw material with hot air passing through the gas feeding chamber 3 and diffusing board 4 to carry out heat exchange with the hot air. The resultant raw material is then fed from the upper part of the partition plates 7 into the fluidizing furnace 2 in the second stage to similarly carry out heat exchange. In the respective fluidizing furnaces 2, heat exchange is successively performed to dehydrate and calcine the raw material. The resultant material is subsequently discharged from the fluidizing furnace 2 in the final stage, passed through the discharging chute 8 and discharged.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a sintering device for sintering gypsum used as construction and other industrial materials, and in particular, a multi-stage continuous flow roasting furnace system with low equipment costs and low fuel consumption. The present invention relates to high-quality gypsum firing equipment. [Prior Art] Calcined gypsum is a gypsum mainly composed of gypsum hemihydrate, and has been widely used for gypsum boards, gypsum plasters, molds for ceramic manufacturing, medical materials, etc. Depending on its use, it can be used as a product. The required properties, especially the degree of activity, are different. It is manufactured by firing natural gypsum or chemical gypsum, which is an industrial product. Type II anhydrite coexists with trihydrate in nature, is produced at the same time as trihydrate, and is also obtained industrially as a byproduct during hydrofluoric acid production, but it has low solubility in water and poor reactivity. It was rarely used industrially. However, recently there has been an increase in demand for granulated blast furnace slag as a main material in the production of high-quality building board materials and as a setting control agent for fast-setting cement. When gypsum monohydrate is heated in the atmosphere at a temperature of 130° C. or higher, some of the crystal water is dehydrated and it becomes gypsum hemihydrate. Add this to 17 more
When fired at 0°C or higher, it becomes soluble anhydrite. When this is further fired at a temperature of 400°C or higher, it becomes a ■-type anhydrite. Soluble anhydrite is an unstable type, absorbing moisture from the air and converting into hemihydrate or trihydrate. Type II anhydrite is a stable type and does not easily undergo a hydration reaction in air. Gypsum is mainly fired in flat kilns, rotary kilns, or single-layer fluidized furnaces. Hiiraki is a batch-operated firing kiln, and because it is easy to operate and the quality of the product is relatively stable, it is used to manufacture calcined gypsum for various purposes. Calcined gypsum that has been fired in a kiln is highly reactive, making it difficult to use for some purposes, so it must be aged. The purpose of aging is to expose the as-fired gypsum to air to hydrate a portion of its surface, thereby deteriorating its surface activity. As gypsum matures, it becomes easier to mix wires, so
It does not require much water to cross-wire, resulting in higher strength. The degree of ripening required for calcined gypsum varies depending on its use, and it is necessary to change the degree of ripening depending on the use of the product. Manufactured calcined gypsum is generally aged by storing it in a storage silo for a long period of time, by storing it in single bags in a warehouse for a long period of time, or by spreading it out on the factory premises for forced contact with air. methods are being used.

[Problem to be solved by the invention]

Firing calcined gypsum by laying flat is easy to operate and the quality of the product is stable, but because it is a batch operation, productivity is low and manufacturing costs are high. Furthermore, equipment costs are high because the equipment is complex. Firing in a rotary kiln is continuous firing, so manufacturing costs can be reduced, but the degree of firing changes due to changes in the moisture content and particle size of the raw material, gypsum, which poses problems in terms of quality control. Additionally, rotary kilns have the disadvantage of high equipment costs. When firing in a single-layer fluidized fluidized furnace, the gypsum supplied to the furnace as a raw material is not discharged as a product one by one, but some of it is short-circuited and not sufficiently fired, so the product is not fired. In order to eliminate unevenness, it is necessary to raise the temperature of the fluidized bed furnace above a certain level, which increases fuel consumption and heat loss. The conventional method of aging calcined gypsum takes a long time to finish aging. This requires special equipment or site. It also has the disadvantage that the degree of ripening changes depending on the weather conditions at the time. An object of the present invention is to solve the problems of the conventional gypsum manufacturing apparatus described above. The purpose is to create a device with a simple structure, low construction cost, and easy maintenance.Another purpose is to create a device that is easy to operate, saves labor through automatic control, and has low manufacturing costs. It is about creating a device. Another objective is to create a device that can consistently produce high-quality products without uneven baking. Yet another object is to obtain a product that does not require any special equipment or place for aging and has a degree of ripeness that corresponds to the desired properties of the product. [Means for Solving the Problems J] The present invention was obtained as a result of intensive research by the inventors based on the above-mentioned objectives, and the main point of its configuration is a multi-stage continuous flow roasting furnace. The present invention will be explained in detail below with reference to FIG. FIG. 1 is a longitudinal sectional view of an embodiment of the invention. In FIG. 1, a firing chamber 1 is a firing chamber that includes a plurality of fluidized furnaces 2 that are partitioned by partition plates 7 and arranged in series, and a gas chamber 12 that serves as a discharge path for firing exhaust gas. Gas supply chamber 3
Firing gas is supplied to the fluidized fluidized furnace 2 from. The diffuser plate 4 is equipped with a nozzle for supplying the firing gas from the gas chamber to the fluidized bed furnace, or has pores in itself, so that the firing gas can be vented. A raw material supply chute 5 for supplying raw gypsum to the firing chamber l, a raw material discharge chute 8 for discharging fired gypsum from the firing chamber, and a gas supply pipe 9 for supplying firing gas to each gas supply chamber are provided. ing. A cold air pipe 15 can be connected to the gas chamber of one or more fluidized bed furnaces. In this case, the gas supply pipe 9 is provided with a cold air damper lO or a hot air damper 11 for switching between the firing gas and the cold air.
It is possible to install The firing exhaust gas is exhausted from the gas exhaust pipe 6. Further, it is preferable that the fluidized bed furnace is provided with a fuel supply pipe 13 for supplying fuel as necessary. Further, a water injection pipe 14 is provided for injecting fine water droplets into the fluidized bed furnace as required. The gypsum calcining apparatus of the present invention can be equipped with a heat exchange device in one or more fluidized chambers of the fluidized fluidized furnace. Heat is supplied to this heat exchange device from the outside. To supply heat to the heat exchange device from the outside, the heat exchange device may be constructed of an electrothermal generating material and may be a device that generates heat through electricity, or a device in which heated gas is passed through the heat exchange device. As the heated gas, air or combustion gas heated by electric heat or combustion gas can be used. Although the arrangement and shape of the heat exchange device are not limited, it is preferable that the heat exchange device be arranged in a direction perpendicular to the diffuser panel and have a shape close to a plate. Further, in the apparatus of the present invention, it is possible to attach a raw material moisture measuring device to one or more of the flow chambers of the flow furnace. This raw material moisture measuring device measures the amount of water adhering to the raw material gypsum and/or the amount of crystallized water in each fluidization chamber, and controls the amount of raw material supplied and the temperature and amount of fluidizing gas so that the amount of water remains constant. Can be done. By keeping the moisture content of the raw material constant in each flow chamber, products of stable quality can be manufactured at low cost. An infrared absorption spectrometer can be suitably used as the raw material moisture measuring device. When installing this measuring device, install a window made of quartz glass or the like on the side wall of the flow chamber so that continuous measurements can be made through it. The fluidized furnaces of the gypsum firing equipment of the present invention can be installed not only linearly and consecutively, but also in any planar arrangement as long as they are continuous, and the shape and area of each fluidizing chamber can also be set arbitrarily. can do. For example, by arranging the fluidized bed furnaces 2a, 2b, 2c, . This makes it possible to reduce short circuits in the raw materials. [Function] Next, the function of firing gypsum in the gypsum firing apparatus of the present invention will be explained. The raw material gypsum supplied to the firing chamber from the raw material supply chute 5 enters the first stage fluidized furnace, where it becomes suspended and fluidized by the hot air that has passed through the gas chamber 3 and the diffuser plate 4, and heat exchange occurs between it and the hot air. be exposed. Next, it enters the second-stage fluidized furnace through the upper part of the partition plate 7, where it similarly exchanges heat in a fluidized state. Heat exchange is performed in each fluidized furnace in turn, and the temperature of the raw gypsum rises, and it is dehydrated and calcined. The raw material is discharged from the final stage fluidized furnace through the raw material discharge chute 8 to the outside of the apparatus. The raw material gypsum to be supplied to this gypsum firing apparatus may be dried in advance and then pulverized before being supplied, or it may be supplied while still containing moisture. The hot air supplied to the gypsum baking device may be combustion gas obtained by burning fuel, heated air heated by electric heat or the like, high-temperature exhaust gas from another device, or a mixture of these. By connecting a cold air pipe 15 to the gas chamber of the final stage fluidized furnace and supplying cold air, the fired gypsum is cooled to prevent unnecessary re-drying during crushing, and the fired gypsum is A portion of it is hydrated and aged by exposing it to cold air. A fuel pipe 13 is installed in one or more fluidized furnaces, and this fuel pipe 13
It is possible to supply more fuel and burn it to increase the firing temperature of the gypsum. By installing the fuel pipe 13, gypsum can be easily fired at a high temperature, and TI and anhydrite can be easily and efficiently obtained. Fine water particles can be injected into the fluidized fluidized furnace from the water injection pipes 14 installed in one or more fluidized fluidized furnaces. By spraying fine water particles, it is possible to enhance the cooling effect of the fired gypsum and increase the degree of maturity of the fired gypsum. When sintering soluble anhydrite or a mixture of soluble anhydrite and gypsum hemihydrate in a single-layer fluidized bed furnace, it is necessary to maintain the entire fluidized bed at the calcination temperature of soluble anhydrite, 190°C or higher. If the heat loss is large and the amount of water adhering to the raw gypsum is large, if it is suddenly exposed to high temperatures, it will solidify, and the fluid state in the fluidization chamber may not be maintained. In the gypsum firing apparatus according to the present invention, each flow chamber can have a different function. That is, the first chamber from the raw gypsum supply side can function as a drying chamber for raw gypsum. Drying of raw material gypsum is 9
This can be done at about 0°C. Therefore, the moisture content of the raw gypsum is high (but it is gradually dried and does not solidify. In the second chamber, the dehydration step from trihydrate gypsum to hemihydrate gypsum can be carried out.Trihydrate gypsum Since the dehydration reaction from hemihydrate gypsum is carried out at 130°C, the temperature of this flow chamber can be maintained at 130°C.In the third chamber, the dehydration reaction from hemihydrate gypsum to soluble anhydrite takes place at 130°C. Since dehydration from hemihydrate gypsum to soluble anhydrite takes place at 190°C, the temperature of this flow chamber is 190°C.
℃ or higher. In the fourth chamber, the calcined gypsum can be cooled or some or all of it can be aged. In the above description, the function is changed for each room, but it is also possible to provide the same function to two or more rooms. For example, if the raw material gypsum has a large amount of water, two or more drying chambers can be used, or if the raw material gypsum particles are thick (if baking is difficult, a dehydration chamber for hemihydrate gypsum or a drying chamber for soluble anhydrite) can be used. It is possible to have two or more dehydration chambers.In addition, if it is necessary to ship soluble anhydrite without ripening, the gypsum baking apparatus of the present invention does not perform cooling or ripening, and the type III moldability is achieved. It is discharged and stored in the form of soluble anhydrite.The drying chamber described above dries the raw gypsum at a temperature of about 90°C, but as the moisture attached to the feedstock gypsum changes, the temperature inside the fluidized bed also changes accordingly. Since the dehydration of gypsum hemihydrate is a reaction that involves a relatively large amount of heat absorption compared to gypsum trihydrate, the temperature of the fluidized chamber in which this reaction takes place is relatively stable.Therefore, the temperature in the fluidized bed can be measured. It is difficult to judge the degree of progress of the reaction.In the flow chamber where soluble anhydrite is dehydrated from gypsum hemihydrate, gypsum hemihydrate and soluble anhydrite coexist, so the temperature inside the bed fluctuates depending on the amount of raw gypsum. If the temperature of this layer rises excessively, some of the soluble anhydrite becomes I
It may metastasize to type I anhydrite, which may reduce product activity. In order to prevent this situation from occurring during equipment operation, the temperature of the fluidized bed must be controlled, but if the residence time of the raw material is long, the time delay will be large (,
Since the temperature fluctuates, it is desirable to keep the amount of raw material entering this variable chamber and the firing state of the raw material constant. For example, in a method where the supply amount of raw gypsum is controlled by the temperature of the drying room, when the moisture content of the raw material increases, the temperature of the drying room decreases, but if the supply amount is decreased in an attempt to raise the temperature, gypsum hemihydrate is more likely than gypsum trihydrate. Although the temperature is approximately constant in the flow chamber where dehydration occurs to soluble anhydrite, the temperature in the flow chamber where dehydration occurs to soluble anhydrite is higher than that of hemihydrate, and type II anhydrite may be produced. Therefore, if it is possible to keep the supply amount of raw gypsum constant and to always send raw gypsum from the drying chamber to the next room in a constant state, the above-mentioned situation will not occur.2. By attaching it and performing heat exchange in a fluidized state, the amount of fluidizing gas can be reduced for the same production volume. Generally, when sintering gypsum in a fluidized bed furnace, the maximum amount of gas is used within a limit that does not scatter the raw materials in the fluidized bed, considering its volumetric efficiency. As a result, more heat is removed from the exhaust gas, and some raw materials are scattered into the exhaust gas. However, by installing a heat exchange device in the fluidization chamber and supplying part of the heat for calcination, it is possible to reduce the amount of fluidization gas, so it is possible to reduce the amount of fluidization gas to the fluidization starting speed. This makes it possible to reduce excess heat loss due to excess gas. Furthermore, since the amount of raw material entrained by the fluidizing gas can be ignored, the fluidizing gas can be circulated as shown in FIG. 4, and a dust removal device such as a pack filter is not required. FIG. 4 shows a calcining apparatus according to the present invention in which a heat exchanger 31 is installed in the fluidized bed in the first chamber. Steam heated in a boiler 32 is separated into steam and water in a steam separator 33, and then heat exchanged. Sent to vessel 3I. The heat exchanger 31 is preferably a plurality of finned tubes connected in parallel and arranged in a fluidized bed so that the tubes are horizontal or vertical. Drainage condensed by heat exchange with the plaster in the first chamber in the heat exchanger 31 is stored in a water tank 34 and sent to the boiler 32 by a pump 35.
supplied to On the other hand, a gypsum temperature measurement controller (TC:) 36 in the fluidized bed in the first chamber controls a fuel pump 37 to control the fuel in the combustor 38 of the boiler. The raw material in the firing chamber 1 is supplied from the raw material supply chute 5 and discharged from the tr+- output chute 8. The gas discharged from the gas discharge pipe 6 is mixed with inlet air 39 as necessary, and is passed through the valve 41 by the fan 40.
It is circulated to each fluidized bed via the valve 42 or discharged outside the system via the valve 42. Circulating fluidized air increases the vapor partial pressure in this circulating air, so it is necessary to graze some of it, but it is better to cool the circulating air and drain it than to graze and draw fresh outside air. There are cases where it is a good idea, so you can choose either one. FIG. 5 shows a heat exchanger 31a for each layer of the fluidized bed. 6 is a system diagram in which circulating fluidizing gas is cooled by a cooler 43 and water 44 is removed. FIG. 7 is a system diagram of an embodiment in which an electric sheathed heater or a far-infrared radiation heater 45 is used as a heat exchanger. The embodiment shown in FIG. 7 has the advantage that the load amount of the fluidized bed furnace can be controlled extremely easily. In the gypsum firing apparatus of the present invention, a raw material moisture measuring device can be attached to one or more of the flow chambers of the flow furnace. As the raw material moisture measuring device, an infrared absorption spectrometer can be suitably used6. This is schematically shown in FIG.
FIG. 2 is a system diagram for controlling the temperature of fluidized air. As shown in FIG. 9, this measuring device 46 has a quartz glass window 48 attached to the side wall of the firing chamber 1, and measures the moisture content of the raw material through this window. In this case, a sensor 49 and an optical fiber 50 can be used. In Figure 8, in drying chamber I, the temperature decreases and rises as the moisture attached to the feedstock increases, while in firing chamber 11, only the decomposition reaction of bound water takes place, so the temperature is almost constant, and in firing chamber III, the temperature is approximately constant. Because water and anhydrous are mixed, the temperature decreases and increases as the amount of product increases and decreases. Since the residence time in the furnace is long, controlling the temperature of firing chamber II would result in a large time delay. When controlling the drying chamber temperature and supply amount, for example, if the moisture content of the raw materials increases, the temperature of the drying chamber will decrease, but if you reduce the supply rate to raise the temperature, the product amount will decrease and baking will be delayed. The temperature of chamber II may rise and JT type anhydrous may occur. Therefore, a quartz glass window is installed on the side wall of the fluidized bed of the drying chamber, and an infrared absorption spectrometer is used through this window to measure the adhering moisture. control. Alternatively, the ratio of gypsum trihydrate to gypsum hemihydrate is measured in the firing chamber (2) in the same manner as above, and the air temperature is controlled by blowing into the drying chamber so that the ratio remains constant. Further, for example, when the moisture content of the raw material increases and the drying chamber temperature decreases, the supply amount is reduced. This causes the temperature of the firing chamber H to rise, but in order to keep this temperature constant,
Reduce the temperature of the blown air. The moisture content of the raw material in the drying chamber during operation is measured using the raw material moisture measuring device. The amount and temperature of the fluidizing gas blown into the drying chamber are adjusted so that this moisture content is always constant. Alternatively, in a flow room where gypsum trihydrate is dehydrated to gypsum hemihydrate, the ratio of gypsum trihydrate to gypsum hemihydrate is measured in the same way, and the flow rate is blown into the drying room so that this ratio is constant. Adjust the amount and temperature of gas. [Example] The present invention will be explained in more detail with reference to Examples below.
The present invention is not limited to the examples described below. Embodiment 1 FIG. 1 is a side sectional view of an embodiment of the present invention. The firing chamber l is a five-stage fluidized furnace 2, as shown in the embodiment in FIG.
Each fluidized bed furnace 2 has a gas supply chamber 3,
Equipped with air diffuser 4. The partition plate 7 between each fluidized furnace has a structure in which the raw material outlet side is lowered in order so that the raw material gypsum flows smoothly from the raw material supply shoe 5 side to the discharge chute 8 side. Although the structure in which the plate 7 is held at the bottom is shown, it is also possible to have a structure in which it is held from the top and the raw gypsum is transferred to the next stage fluidized furnace through the gap at the bottom of the partition plate. It is also possible to have a structure in which the height or the width of the gap at the bottom of the partition plate can be adjusted.As shown in Figure 3, the upper part of the firing chamber It is also possible to have a structure that is wider than the width of the fluidized fluidized furnace for the purpose of settling the gypsum particles and returning them to the fluidized fluidized furnace 2.The diffuser plate 4 is made of a stainless steel plate with a stainless steel nozzle attached. However, the diffuser plate is not limited to this, and it is also possible to use a perforated plate made of ceramic or metal. Fig. 2 is a flow sheet of the entire apparatus including the apparatus of the embodiment of the present invention. The main components of this overall device are: a firing chamber 1 in which a plurality of fluidized furnaces are arranged side by side; a raw material quantitative feeder 22 that supplies raw gypsum to the firing chamber 1; a calcined gypsum hopper 23 that stores calcined gypsum; A crusher 1124 for crushing calcined gypsum, an aging hopper 25 for aging the crushed gypsum, an air heater 26 for heating the firing gas to the firing chamber, a blowing fan 29 for blowing the firing gas into the fluidized furnace, and a firing chamber. a cold air fan 27 for supplying cold air to the furnace, and an exhaust duct 28 for drawing exhaust gas from the firing chamber to the outside.The raw material quantitative supply device 22 includes six raw material quantitative supply machines 22 consisting of a hopper, a table feeder, and a screw conveyor. The raw material gypsum supplied to the first stage fluidized furnace by the table feeder is suspended and dried and heated in a fluidized state by heated air from the gas chamber through the diffuser panel. Although it is not limited to a screw conveyor, it is desirable to use a highly airtight conveyor in order to prevent air from entering or exiting the firing chamber as much as possible.The raw material firing gas is air heated by preheating the tarinka cooler of the cement firing equipment. This heated air was
If necessary, it was further heated with an air heater 26 before use. By heating the air with Talinkatara's residual heat, fuel consumption was significantly reduced. In this device, the firing exhaust gas discharged from the exhaust duct 28 is guided to a bag filter for the tarinka cooler, and after collecting fine gypsum particles contained therein, it is discharged to the outside air. The gypsum heated in the first stage fluidized furnace passes through the partition plate between the first and second stage fluidized furnaces and enters the second stage fluidized furnace. The gypsum is further heated in the second stage fluidized furnace. Similar conditions are repeated, and in each stage of the fluidized furnace, the raw gypsum is fluidized by hot air, efficiently exchanges heat with the hot air, and undergoes a firing action such as drying and dehydration of adhering moisture. Since the gypsum is fired efficiently in each stage of the fluidized fluidized furnace, the fired gypsum is of high quality with no uneven firing. By installing a damper on the wind pipe that enters the gas chamber and adjusting its opening degree, It is also possible to control the amount of heated air that enters each fluidized bed furnace.By adjusting the amount of heated air that enters the fluidized bed furnace, the fluidization state of raw gypsum in the fluidized bed furnace can be managed in a fluidized bed state. It is also possible to control the gypsum in a so-called spouted bed state, which is an even more intense fluid state.The degree of calcination can be changed by changing the amount of gypsum supplied,
This can be easily done by changing the temperature of hot air, changing the amount of hot air, etc. By taking these measures, it is possible to always maintain an appropriate operating state in response to disturbances such as changes in the water content and particle size of the raw gypsum. The fired gypsum is cooled in the final stage fluidized furnace by a cold air fan 27, and a part of the gypsum is aged and then stored in the calcined gypsum hopper 23. The calcined gypsum extracted from the calcined gypsum hopper 23 by the screw conveyor is crushed by the crusher 24, and some of the calcined products can be made into products at this stage, and the remaining calcined products enter the aging hopper 25 and are Inside, it is exposed to cold air and further matured into a product. The final stage of the fluidized furnace is designed to cool the gypsum by blowing cold air with a cooling fan. The purpose of cooling the gypsum with cold air is to prevent unnecessary dehydration of the gypsum and fluctuations in product quality if the gypsum is at a high temperature during crushing, and to hydrate a portion of the fired gypsum. to let;
In other words, the goal is to finish the initial stages of ripening. Depending on the intended use of the product, it is possible to terminate the aging at this stage. Furthermore, by increasing the number of fluidized bed furnaces that can be blown with cold air, it is possible to obtain different degrees of ripeness as required by the product. The structure allows the fuel supply pipe I3 to be attached to the third and fourth stage fluidized furnaces. By injecting fuel into the fluidized bed through this fuel supply pipe and combusting it within the bed, the firing temperature can be easily increased, and IIr anhydrite can be easily produced. In addition, the structure allows for the installation of a water injection tube that blows fine water droplets into the final stage fluidized bed. By injecting fine water droplets into the fluidized bed furnace using this water injection pipe, it is possible to increase the cooling efficiency of the calcined gypsum and to increase the degree of maturation of the gypsum. The amount of water injected can be varied depending on the requirements of the product plaster. For products that require a degree of ripeness that is still difficult to achieve even with the use of the above-mentioned ripening means, it is possible to further ripen them in a ripening hopper. The aging hopper matures the gypsum by blowing cold air into it. Example-2 FIG. 4 is a flowchart and a schematic diagram of the example. The structure of the furnace body is the same as that shown in Figure 1. In Figure 4, room 1 is a drying room, room 2 is a baking room, and room 3 is a drying room.
Although the chamber is designated as the firing chamber if, four or five chambers may be provided for aging as in Example 1. The raw material gypsum supplied in a fixed amount to the fluidized fluidized furnace is suspended by circulating air from the gas chamber through a diffuser plate, and is dried and heated in a fluidized state by heat exchange with a steam pipe placed in the fluidized fluidized chamber. Steam passes through the steam separator from the boiler and flows through the steam pipe.
After heat exchange, the steam is returned to the water tank and recirculated. The temperature in the furnace layer is adjusted by the steaming temperature, and the steam temperature is controlled by the boiler fuel. At that time, the temperature inside one base layer was 90℃,
The temperature in room 2 is 130°C and the temperature in room 13 is 170°C. In this case, since the furnace chamber is divided into three chambers, a boiler is installed in each chamber (FIG. 4 shows only one boiler). The number of boilers may be two by sending the steam heat-exchanged in the three chambers to the steam pipe in one chamber and reusing it. After the fluidizing air is collected by a cyclone from the furnace outlet, it is blown into the diffuser again from the circulation fan. The products collected by the cyclone also contain gypsum trihydrate and gypsum hemihydrate, so they are returned to room 1 and reheated. Example-3 As shown in Figure 8, an infrared absorption spectrometer was used as a control sensor in the equipment shown in Figures 1 and 2 to measure the proportions of moisture, gypsum trihydrate, and gypsum hemihydrate. and feeds back to the blown air heater. ■The purpose of the chamber is to dry the water adhering to the raw material gypsum (usually 8 to 10% moisture).The moisture content is measured with a sensor, and the amount of hot air for fluidization is adjusted so that the adhering water is almost O2. It is kept constant and the amount of ore supplied is controlled to increase or decrease. In the second chamber, the purpose is to decompose the bound water and react to the hemihydrate gypsum.By measuring the amount of bound water, the ratio of hemihydrate gypsum to trihydrate gypsum is determined, and with the above control. When the amount of ore feed decreases, the temperature in the layer increases and the temperature of the flowing hot air is controlled to increase or decrease in order to prevent the formation of type II anhydride. [Effects of the Invention] As explained above, the present invention is a multi-stage continuous flow torrefaction furnace, which has the following advantages when compared with conventional gypsum calcining equipment: (1) The structure is simple, the construction cost is low, and maintenance is easy. is easy. (2) Operation is easy and automation and labor saving are possible. (3) It can easily respond to disturbances such as fluctuations in moisture content and changes in particle size. (4) Since it is a multi-stage continuous flow roasting furnace, the raw materials are sufficiently fired in each stage of the flow furnace, so there is no uneven baking and the quality of the product is stable. (5) Aging can be performed in the same equipment as baking, and can be performed in multiple stages according to product requirements. Additionally, L/X does not require special equipment or premises for aging like conventional equipment. It has the above advantages and is industrially useful.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view of an embodiment of the present invention, Fig. 2 is an overall flow sheet of an embodiment of the present invention, Fig. 3 is a cross-sectional view of another embodiment, and Figs. 4 to 7 are firing A flow sheet of an example in which a heat exchanger is installed indoors, Fig. 8 is a flow sheet of a control system using an infrared spectrometer, Fig. 9 is an installation relationship diagram of an infrared spectrometer, Fig. 1O, FIG. 11 is a plan view of the firing chamber of another embodiment. l...-Firing chamber 3...Gas supply chamber 5...Raw material supply chute 7-...Partition plate 9...Gas supply pipe 11...Hot air damper 13...Fuel supply pipe 2--Flow Furnace 4...Diffuser panel 6...Gas discharge pipe 8...Discharge chute 10...Cold air damper 12--Gas chamber 14...Water injection pipe

Claims (1)

[Claims] 1. A firing chamber in which a plurality of fluidized fluidized furnaces are arranged in series separated by a partition plate, and each fluidized fluidized furnace is separated into a gas chamber and a fluidized chamber, and the flow of gas supplied from the gas chamber to the fluidized chamber is controlled. An air diffuser for uniform distribution, a gas supply pipe for supplying firing gas to each gas chamber, a gas discharge pipe for discharging gas from the firing chamber, a raw material supply chute for supplying raw materials to the fluidized furnace, and a firing A gypsum firing device equipped with a discharge chute for discharging fired products from a chamber. 2. The gypsum firing apparatus according to claim 1, wherein a heat exchange device is attached to the fluidization chamber of at least one fluidized bed furnace, and heat is supplied to the heat exchange device from the outside to exchange heat with the raw material in a fluidized state. 3 Attach a raw material moisture measuring device to the fluidization chamber of one or more fluidized bed furnaces, measure the amount of moisture adhering to the raw material and/or the amount of crystallized water in the fluidizing chamber using the device, and check that the amount of moisture adhering to the raw material and/or amount of crystallized water is constant. 1. A method for controlling a gypsum firing apparatus, characterized by controlling the temperature of a fluidizing chamber so that the temperature of the fluidizing chamber is 4. The gypsum firing apparatus according to claim 1, further comprising a cold air pipe for supplying cold air to the gas chamber of at least one fluidized fluidized furnace, and a water injection pipe.