CN210560117U - Anhydrous gypsum preparation system - Google Patents

Abstract

The utility model relates to an anhydrous gypsum preparation system, which comprises a first hot-blast stove, a drying crusher, a powder concentrator, a dust collector, a fan, a chimney, a preheating dehydration module, a second hot-blast stove, a cooling device, a first air valve, a second air valve, a first cold air valve, a flue gas purification device, a third air valve and a second cold air valve; the first hot blast stove, the drying crusher, the powder concentrator, the dust collector, the fan and the chimney are sequentially connected on the gas path; the drying crusher, the powder concentrator, the dust collector, the preheating dehydration module and the cooling device are sequentially connected on a material path; the utility model discloses a suspension calcining device realizes the heat transfer step by step to thoroughly detach the moisture in the ardealite, in order to make high-quality II type anhydrous gypsum, and possess the control by temperature change function, can prevent hot-blast equipment of burning out when disconnected material or other unusual operating modes, eliminated the potential safety hazard.

Description

Anhydrous gypsum preparation system

Technical Field

The utility model relates to an anhydrous gypsum preparation system.

Background

The phosphogypsum is an industrial byproduct generated in the process of preparing phosphoric acid, the main mineral component in the phosphogypsum is gypsum, calcium sulfate dihydrate is used as the main component, and quartz and mineral dressing agent residues are used as the secondary components; the phosphogypsum is randomly piled to destroy the acid-base property of soil, and water-soluble phosphorus and fluorine flow into rivers along with rainwater to seriously pollute the water quality, so the phosphogypsum can be piled after being treated; because phosphogypsum contains high moisture content and also contains certain impurities, although the main components of the phosphogypsum are the same as natural gypsum, the phosphogypsum cannot be directly treated like the natural gypsum.

the phosphogypsum can be made into dihydrate gypsum dry powder, hemihydrate gypsum and anhydrous gypsum by the process technologies of removing impurities, drying external water, decomposing crystal water and the like, and can be used in the field of building materials, according to different process conditions, the prepared product is different from crystal forms, α type hemihydrate gypsum can be prepared by heating dihydrate gypsum to 135-200 ℃ in a high-pressure or steaming mode, the α type hemihydrate gypsum has higher strength, but complex process and strict control conditions, the production mode is discontinuous production and is difficult to realize large-scale industrial production, if a calcining mode is adopted, β -type hemihydrate gypsum can be prepared by heating to 160-200 ℃, β -type hemihydrate gypsum has the advantages of heat preservation, light weight, quick solidification, small shrinkage and the like, but the strength and water resistance of the hemihydrate gypsum are poor, if the calcining mode is adopted, the gypsum can be converted into the II-type anhydrous gypsum under the conditions of 360-1180 ℃ and normal pressure, the II-type anhydrous gypsum has good water resistance and strength, and the strength is higher than that of the α type type hemihydrate gypsum.

The method for preparing the phosphogypsum into the type II anhydrous gypsum by calcining and dehydrating is a better method for recycling the phosphogypsum at present, most of the existing anhydrous gypsum preparation systems adopt a centralized calcining method to treat the phosphogypsum, the water in the phosphogypsum cannot be fully and thoroughly removed, and the quality of the prepared product is lower; and the lack of temperature control function leads to that the hot-blast that produces of calcination is very easy when disconnected material or other abnormal operating mode, burns out equipment, has the potential safety hazard, waits for further improvement.

SUMMERY OF THE UTILITY MODEL

To the current situation of above-mentioned prior art, the utility model aims to solve the technical problem that an adopt suspension calcining device to realize step by step the heat transfer thoroughly detach the moisture in the ardealite and improved the quality of II type anhydrite, and possess the anhydrite preparation system of control by temperature change function in order to eliminate the potential safety hazard.

The utility model provides a technical scheme that above-mentioned technical problem adopted does: a preparation system of anhydrous gypsum comprises a first hot blast stove, a drying crusher, a powder concentrator, a dust collector, a fan, a chimney, a preheating dehydration module, a second hot blast stove, a cooling device, a first air valve, a second air valve, a first cold air valve, a flue gas purification device, a third air valve and a second cold air valve, and is characterized in that the first hot blast stove, the drying crusher, the powder concentrator, the dust collector, the fan and the chimney are sequentially connected on a gas path; the drying crusher, the powder concentrator, the dust collector, the preheating dehydration module and the cooling device are sequentially connected on a material path; the second hot blast stove is connected with an air inlet of the preheating and dehydrating module, and an air outlet of the preheating and dehydrating module is connected with an air inlet pipe of the drying crusher; a first air valve is arranged on an air outlet pipe of the first hot blast stove, a second air valve is arranged between an air outlet of the preheating and dehydrating module and an air inlet pipe of the drying crusher, and a first cold air valve is also arranged on the air outlet pipe of the first hot blast stove; still be provided with gas cleaning device between dust collector and the fan, be provided with the third blast gate between the air-out pipe of preheating the dehydration module and the air-supply line of dust collector, be provided with the second cold-blast valve between preheating the dehydration module and the second hot-blast furnace.

Preferably, the preheating dewatering module comprises a plurality of cyclone preheating devices connected in series.

Preferably, the device further comprises a conveying belt, and the conveying belt is arranged below a slag discharge port of the dust collector.

Compared with the prior art, the utility model has the advantages of: the utility model discloses a suspension calcining device realizes the heat transfer step by step to thoroughly detach the moisture in the ardealite, in order to make high-quality II type anhydrous gypsum, and possess the control by temperature change function, can prevent hot-blast equipment of burning out when disconnected material or other unusual operating modes, eliminated the potential safety hazard.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Detailed Description

As shown in fig. 1, an anhydrous gypsum preparation system includes a first hot-blast stove 1, a drying crusher 2, a powder concentrator 3, a dust collector 4, a fan 5, a chimney 6, a preheating dehydration module 7, a second hot-blast stove 8, a cooling device 9, a first air valve 10, a second air valve 11, a first cold air valve 12, a flue gas purification device 13, a third air valve 14, a second cold air valve 15 and a conveyor belt 17; the first hot blast stove 1, the drying crusher 2, the powder concentrator 3, the dust collector 4, the fan 5 and the chimney 6 are connected in sequence on the gas path; the drying crusher 2, the powder concentrator 3, the dust collector 4, the preheating dehydration module 7 and the cooling device 9 are connected in sequence on a material path; the second hot blast stove 8 is connected with an air inlet of the preheating and dehydrating module 7, and an air outlet of the preheating and dehydrating module 7 is connected with an air inlet pipe of the drying crusher 2; the preheating dehydration module 7 comprises a plurality of cyclone preheating devices 16 which are connected in series; the conveyer belt 17 is arranged below a slag discharge port of the dust collector 4; a first air valve 10 is further arranged on an air outlet pipe of the first hot blast stove 1, and the first air valve 10 is used for controlling and adjusting smoke of the first hot blast stove 1; a second air valve 11 is arranged between an air outlet of the preheating and dehydrating module 7 and an air inlet pipe of the drying crusher 2, the second air valve 11 is used for controlling and adjusting the air quantity transmitted into the drying crusher 2 by the preheating and dehydrating module 7, and the proper proportion of two waste gases is realized by adjusting and controlling the first air valve 10 and the second air valve 11 so as to conveniently adjust the powder selecting air quantity, the belt material concentration and the drying and dehydrating effects; the air outlet pipe of the first hot blast stove 1 is also provided with a first cold air valve 12 for controlling and adjusting the air volume and temperature of the flue gas at the outlet of the first hot blast stove 1 so as to better adapt to the air volume required by the drying crusher 2 and the powder concentrator 3 and meet the requirements of air flow material carrying and powder concentration; meanwhile, the temperature of the flue gas discharged from the first hot blast stove 1 can be prevented from being too high, when the abnormal working condition of material breakage occurs, the first cold air valve 12 is opened to mix cold air, so that the drying crusher 2 and subsequent equipment are prevented from being burnt out by the too high temperature of the flue gas, and a flue gas purification device 13 is arranged between the dust collector 4 and the fan 5 and used for removing harmful substances such as sulfur, phosphorus and the like in the flue gas so as to meet the emission index of the environmental protection requirement; a third air valve 14 is arranged between the air outlet pipe of the preheating dehydration module 7 and the air inlet pipe of the dust collector 4, is used for controlling and adjusting the air inlet amount of the dust collector 4, and can also be adjusted together with the second air valve 11, so that the air volume of two paths of flue gas discharged from the preheating dehydration module 7 to the drying crusher 2 and the dust collector 4 is adjusted; a second cold air valve 15 is arranged between the preheating dehydration module 7 and the second hot air furnace 8 and used for adjusting the temperature of hot air entering the preheating dehydration module 7 and used for removing phosphogypsum crystal water, so that the hot air is not too high, and when abnormal working conditions of material breakage occur, the preheating dehydration module 7 and subsequent equipment are burnt out at the not too high temperature, thereby playing an emergency protection role.

The process flow comprises the following steps: the first hot blast stove 1 provides fuel smoke gas for the drying crusher 2, the smoke gas enters the drying crusher 2 from an air inlet of the drying crusher 2, phosphogypsum raw materials enter the drying crusher 2 from a feed inlet of the drying crusher 2, the steps of scattering and drying and removing external water are completed in the drying crusher 2, the scattered powdery phosphogypsum is brought into the powder concentrator 3 by drying hot air for powder classification, coarse powder returns to the drying crusher 2, fine powder is brought into the dust collector 4 by air flow, further, the collection of the dry powdery phosphogypsum (or part of semi-hydrated gypsum) is realized, and waste gas generated in the dust collector 4 is discharged into the atmosphere through a fan 5 and a chimney 6; if the temperature in the drying crusher 2 is higher (more than or equal to 150 ℃), most of the semi-hydrated gypsum can be prepared from the materials discharged from the drying crusher 2, and the semi-hydrated gypsum still contains part of dry powder dihydrate gypsum due to short drying time; the dried dry powder phosphogypsum is sent into a preheating and dehydrating module 7 for removing crystal water, a second hot blast stove 8 provides hot flue gas for the preheating and dehydrating module 7, and then the crystal water of the dry powder phosphogypsum is removed to prepare powdery anhydrous gypsum, and then the powdery anhydrous gypsum is sent into a cooling device 9 for cooling; the materials run from top to bottom along a plurality of cyclone preheating devices 16 in the preheating dehydration module 7, hot air generated by a second hot blast stove 8 runs from bottom to top along the plurality of cyclone preheating devices 16, and the hot air and the materials perform step-by-step heat exchange to complete crystal water removal in the heat exchange process, wherein the hot air at the lowest stage is controlled to be more than 400 ℃ so as to realize the complete removal of the remaining half crystal water of the phosphogypsum and prepare the type II anhydrous gypsum; an air outlet pipe in the preheating dehydration module 7 is divided into two paths, one path is connected with an air inlet pipe of the drying crusher 2 and enters the drying crusher 2 together with hot flue gas from the first hot blast stove 1, and then high-moisture phosphogypsum is dried and external water is removed; the other path is connected with an air inlet pipe of a dust collector 4, hot flue gas of phosphogypsum after crystal water is removed by a preheating dehydration module 7 is directly merged with waste gas discharged by a powder concentrator 3 of a drying and crushing system and enters the dust collector 4 together, and the merged waste gas is filtered by the dust collector 4 and then is discharged into the atmosphere through a fan 5 and a chimney 6; the impurities absorbed in the dust collector 4 can be periodically discharged through the conveyor belt 17; when the water content of the phosphogypsum is high, the third air valve 14 can be closed, and hot flue gas completely enters the drying crusher 2, so that the hot air heat of the first hot air furnace 1 is reduced, and the energy consumption of a system is further reduced; when the moisture of the phosphogypsum is small, the first air valve 10 can be cut off, and all drying hot air in the drying crusher 2 comes from the preheating dehydration module 7, so that waste gas generated by the drying crusher 2 is connected with the air passage of the preheating dehydration module 7 in series; when the temperature of the exhaust gas of the preheating and dehydrating module 7 is lower than that of the exhaust gas discharged by the drying and crushing machine 2, the second air valve 11 can be closed, the third air valve 14 can be opened, the exhaust gas generated by the preheating and dehydrating module 7 completely enters the dust collector 4, and the exhaust gas generated by the drying and crushing machine 2 and the gas path of the preheating and dehydrating module 7 are mutually connected in parallel.

The method for preparing the phosphogypsum into the type II anhydrous gypsum through calcining and dehydrating is a better method for recycling the phosphogypsum, most of the existing anhydrous gypsum preparation systems adopt a centralized calcining method to treat the phosphogypsum, the water in the phosphogypsum cannot be fully and thoroughly removed, and the quality of the prepared product is lower; the device is easy to burn out when the material is cut off or other abnormal working conditions are caused by the lack of the temperature control function, so that potential safety hazards exist; the utility model discloses a suspension calcining device realizes the heat transfer step by step to thoroughly detach the moisture in the ardealite, in order to make high-quality II type anhydrous gypsum, and possess the control by temperature change function, can prevent hot-blast equipment of burning out when disconnected material or other unusual operating modes, eliminated the potential safety hazard.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that various changes in the embodiments and modifications thereof may be made, and equivalents may be substituted for elements thereof; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.

Claims (3)

1. A preparation system of anhydrous gypsum comprises a first hot blast stove, a drying crusher, a powder concentrator, a dust collector, a fan, a chimney, a preheating dehydration module, a second hot blast stove, a cooling device, a first air valve, a second air valve, a first cold air valve, a flue gas purification device, a third air valve and a second cold air valve, and is characterized in that the first hot blast stove, the drying crusher, the powder concentrator, the dust collector, the fan and the chimney are sequentially connected on a gas path; the drying crusher, the powder concentrator, the dust collector, the preheating dehydration module and the cooling device are sequentially connected on a material path; the second hot blast stove is connected with an air inlet of the preheating and dehydrating module, and an air outlet of the preheating and dehydrating module is connected with an air inlet pipe of the drying crusher; a first air valve is arranged on an air outlet pipe of the first hot blast stove, a second air valve is arranged between an air outlet of the preheating and dehydrating module and an air inlet pipe of the drying crusher, and a first cold air valve is also arranged on the air outlet pipe of the first hot blast stove; still be provided with gas cleaning device between dust collector and the fan, be provided with the third blast gate between the air-out pipe of preheating the dehydration module and the air-supply line of dust collector, be provided with the second cold-blast valve between preheating the dehydration module and the second hot-blast furnace.

2. The anhydrous gypsum preparation system of claim 1, wherein the pre-heating dehydration module comprises a plurality of cyclone pre-heating devices connected in series.

3. The anhydrous gypsum preparation system of claim 1, further comprising a conveyor belt disposed below the slag discharge port of the dust collector.

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