Device for producing building gypsum by using flue gas desulfurization gypsum

Abstract

The utility model relates to a device for producing building gypsum by using flue gas desulfurization gypsum, which comprises a wet material beater, the wet material beater is connected with a bulk material mixer, the bulk material mixer is connected with a gypsum wet material bin, and the gypsum wet material bin is connected with a gypsum dryer. The gypsum drying device is further connected with a first air feeder, a first cloth bag collector, a high-temperature heat carrier particle generator, a gypsum calciner and a low-temperature heat carrier particle diverter, the low-temperature heat carrier particle diverter is further connected with a bulk material mixer and the high-temperature heat carrier particle generator, and a gypsum raw material bin is connected with the gypsum calciner. The device has the advantages that high-temperature heat carrier particles are used as a direct heat source of the drying device and the calcining device, have huge temperature difference with flue gas desulfurization gypsum, are directly mixed and contacted for heat exchange under fluidization, are particles of dozens of microns to hundreds of microns and have larger specific surface area, and the drying device and the calcining device are directly mixed and contacted for heat exchange. And the gypsum drying device, the gypsum calcining device and the high-temperature heat carrier particle generating furnace are not provided with pressure-bearing metal heat exchange surfaces, so that the equipment investment is low.

Description

Technical Field

[0001] The utility model relates to the technical field of resource recycling of gypsum solid waste, in particular to a device for producing building gypsum by utilizing flue gas desulfurization gypsum. Background Art

[0002] Desulfurization gypsum refers to solid waste with gypsum as the main component produced in the process of exhaust gas desulfurization. According to the provisions of GB / T39198 "Classification and Code of General Solid Wastes", the category code of desulfurization gypsum is 65, which belongs to general solid waste. Furthermore, "Flue Gas Desulfurization Gypsum" in GB / T 37785-2019 "Flue Gas Desulfurization Gypsum" refers to solid waste with calcium sulfate dihydrate (CaSO4·2H2O) as the main component produced by desulfurization and purification of sulfur-containing flue gas using limestone / lime-gypsum wet method. According to the provisions of GB / T 37785-2019 "Flue Gas Desulfurization Gypsum", the content of calcium sulfate dihydrate (CaSO4·2H2O) in the dry matter of flue gas desulfurization gypsum after drying is above 85%, and the first-grade product can reach 95%.

[0003] According to the definition of GB / T 9776-2022 "Building Gypsum", building gypsum refers to a powdered cementitious material used for building materials, which is obtained by calcining and dehydrating natural gypsum or industrial by-product gypsum at a certain temperature, with β-calcium sulfate hemihydrate (β-CaSO4·1 / 2H2O) as the main component, without any admixtures or additives. Regarding technical requirements, GB / T 9776-2022 "Building Gypsum" stipulates that the sum of the content of effective cementitious materials β-calcium sulfate hemihydrate (β-CaSO4·1 / 2H2O) and soluble anhydrous calcium sulfate (AIII-CaSO4) in the product should not be less than 60.0%, and the content of calcium sulfate dihydrate (CaSO4·2H2O) should not be more than 4%. It can be seen that after drying and calcining, the content of effective ingredients in flue gas desulfurization gypsum fully meets the requirements of building gypsum.

[0004] Flue gas desulfurization gypsum is a wet material containing 10-15% water. After drying at a temperature of about 110°C, gypsum dry powder can be obtained. Its main component is calcium sulfate dihydrate. Calcium sulfate dihydrate (CaSO4•2H2O) needs to be calcined at a temperature of 170-200°C to generate β-hemihydrate calcium sulfate (β-CaSO4•1 / 2H2O), while the calcination temperature of type III anhydrous calcium sulfate (AIII-CaSO4) needs to be 230°C. The first generation of dry calcination technology uses flue gas as a heat carrier. The disadvantage is that the volume energy density is too low, resulting in a large equipment volume and low energy utilization efficiency. The second generation of dry calcination technology uses steam as a heat carrier, which increases the volume energy density, but the steam heat exchange equipment is a pressure vessel, which has high investment and great safety hazards. In addition, due to the limitation of steam temperature, only β-hemihydrate calcium sulfate can be produced, and type II anhydrous calcium sulfate cannot be produced. In order to solve the above technical problems, at this stage, there is an urgent need for a device with high heat per unit volume and small equipment volume under normal pressure for use in the production of building gypsum. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides a device for producing building gypsum by utilizing flue gas desulfurization gypsum.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A device for producing building gypsum using flue gas desulfurization gypsum, characterized in that it comprises a wet material scattering machine, the wet material scattering machine is connected to a bulk material mixer, the bulk material mixer is connected to a bulk material conveyor, the bulk material conveyor is connected to a gypsum wet material bin, the gypsum wet material bin is connected to a gypsum dryer through a first weighing feeder, the gypsum dryer is also connected to a first blower, a first bag receiver, a high-temperature heat carrier particle generator, a gypsum calciner and a low-temperature heat carrier particle diverter, and the low-temperature heat carrier particle diverter is also connected to the bulk material mixer and the high-temperature heat carrier particle generator;

[0008] The first bag receiver is also connected to the gypsum raw material bin and the exhaust pipe, the gypsum raw material bin is connected to the second weighing feeder, and the second weighing feeder is connected to the gypsum calciner;

[0009] The gypsum calciner is also connected to the second blower, the second bag collector and the high-temperature heat carrier particle generator. The second bag collector is also connected to the exhaust pipe. The second bag collector is connected to the gypsum clinker bin, and the gypsum clinker bin is connected to the clinker cooler.

[0010] On the basis of the above scheme, the following technical scheme can also be adopted:

[0011] A first pipe is connected between the first bag collector and the exhaust pipe, and a first induced draft fan is connected to the first pipe. A second pipe is connected between the second bag collector and the exhaust pipe, and a second induced draft fan is connected to the second pipe.

[0012] The first pipeline is connected to a first valve, the first pipeline is connected to a waste heat recovery device through a third pipeline, the third pipeline is connected to the front side of the first valve, and the third pipeline is connected to a third valve;

[0013] The second pipeline is connected to a second valve, the second pipeline is connected to a waste heat recovery device through a fourth pipeline, the fourth pipeline is connected to the front side of the second valve, and the fourth pipeline is connected to a fourth valve;

[0014] The waste heat recovery device is also connected to the exhaust pipe through a fifth pipe, and a fifth valve is connected to the fifth pipe. A condensate outlet, a cold water inlet and a hot water outlet are also provided on the waste heat recovery device.

[0015] An iron remover is also installed on the bulk material conveyor.

[0016] The gypsum dryer comprises a first shell, a first air distribution plate is installed in the first shell, a first wind box is installed on the lower side of the first air distribution plate, a first dilute phase zone and a first dense phase zone are provided in the cavity of the first shell on the upper side of the first air distribution plate, and the first dilute phase zone is arranged on the upper side of the first dense phase zone;

[0017] There is a feed port for the wet material of flue gas desulfurization gypsum in the center of the top plate head of the first dilute phase zone, and a feed pipe is also connected in the first shell. The feed port of the feed pipe is arranged outside the head of the first shell, and the discharge port of the feed pipe is arranged in the middle position of the lower side of the first dense phase zone.

[0018] A first cyclone separator is also installed in the fluidized bed dryer. The first cyclone separator is installed at the tail of the fluidized bed dryer. The inlet of the first cyclone separator is close to the top plate of the first dilute phase zone. The first gas outlet of the first cyclone separator is arranged on the upper side of the first shell. The discharge port on the lower side of the first cyclone separator is connected to the first discharge pipe. The discharge port of the first discharge pipe is arranged on the outside of the first shell. A main discharge port for heat carrier particles is also provided on the first air distribution plate at the tail of the fluidized bed dryer.

[0019] The gypsum calciner comprises a second shell, in which a mixing calcination zone and a separation discharge zone are arranged;

[0020] The mixed calcination zone includes a second air distribution plate, a first wind box is installed on the lower side of the second air distribution plate, a second dilute phase zone and a second dense phase zone are arranged in the cavity of the second shell on the upper side of the second air distribution plate, and the second dilute phase zone is arranged on the upper side of the second dense phase zone;

[0021] The separation and discharge area includes a third air distribution plate, a third wind box is installed on the lower side of the third air distribution plate, and a third dilute phase area and a third dense phase area are arranged in the cavity of the second shell on the upper side of the third air distribution plate, and the third dilute phase area is arranged on the upper side of the third dense phase area;

[0022] A group of gypsum dry powder feed inlets are provided on one side of the second dense phase zone, a group of high-temperature heat carrier particle feed inlets are provided on the other side, and a heat carrier particle discharge port is provided on the third air distribution plate;

[0023] A second cyclone separator is also installed in the fluidized bed calciner. The inlet of the second cyclone separator is close to the top plate of the second rarefied phase zone. The second gas outlet of the second cyclone separator is arranged on the upper side of the second shell. The discharge port on the lower side of the second cyclone separator is connected to the second discharge pipe. The discharge port of the second discharge pipe is arranged on the outside of the second shell.

[0024] The empty tower standard gas velocity at the bottom of the dense phase zone of the fluidized bed of the gypsum dryer and the gypsum calciner is 0.2-0.5 m / s.

[0025] The fuel of the high-temperature heat carrier particle generator is solid fuel or gas fuel, the particle size of the high-temperature heat carrier particles used is in the range of 200 μm-600 μm, and the temperature of the produced high-temperature heat carrier particles is 750-950°C.

[0026] The beneficial effects of the utility model are as follows: the device adopts high-temperature heat carrier particles of 750-950°C as the direct heat source of the dryer and the calciner, which is much higher than the steam heat source temperature of the traditional technology. There is a huge temperature difference between the high-temperature heat carrier particles and the flue gas desulfurization gypsum, the heat exchange effect is good, the calcination temperature is uniform and controllable, there is neither overburning nor underburning, and the product quality is good.

[0027] High-temperature heat carrier particles and desulfurized gypsum are directly mixed for contact heat exchange. Both are particles ranging from tens to hundreds of microns in size and have a huge specific surface area. Under the action of fluidization, the contact area between the two is much larger than the traditional technical solution using steam, and the heat exchange efficiency is much higher.

[0028] Solid particles are used as heat carriers. The gypsum dryer, gypsum calciner and high-temperature heat carrier particle generator do not have pressurized metal heat exchange surfaces and are not pressure vessels. The equipment investment is low, the maintenance workload is small, and the cost is saved.

[0029] The exhaust gas discharged from the gypsum dryer and gypsum calciner has a high water vapor content, which can be used for waste heat recovery, greatly improving the energy efficiency of the entire system.

[0030] The overall system has a high degree of automation, and continuous production is carried out under computer control, which greatly improves labor productivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a basic structural schematic diagram of the utility model;

[0032] Figure 2 It is a basic structural diagram of a gypsum dryer;

[0033] Figure 3 for Figure 2 Cross-sectional view in the AA direction;

[0034] Figure 4 for Figure 2 Cross-sectional view in the BB direction;

[0035] Figure 5 It is a basic structural schematic diagram of a gypsum calciner;

[0036] Figure 6 for Figure 5 A top view of

[0037] Figure 7 for Figure 5 Cross-sectional view in the AA direction;

[0038] Figure 8 for Figure 5 Cross-sectional view in the BB direction;

[0039] Fig. 9 for Figure 5 Cross-sectional view along the CC direction. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0041] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0042] like Figure 1As shown, the utility model relates to a device for producing building gypsum using flue gas desulfurization gypsum, including a wet material dispersing machine 1, the wet material dispersing machine 1 including a casing, relatively rotating rollers are installed in the casing, and a stirring rod is provided on each rotating roller. A material inlet 1.1 is provided on the upper side of the casing, and a material outlet 1.2 is provided on the lower side of the casing. The material outlet 1.2 is connected to the first inlet 2.1 of the bulk material mixer 2 through a pipeline. The second inlet 2.2 of the bulk material mixer 2 is connected to the low-temperature heat carrier particle diverter 20, and the material flow rate of the second inlet 2.2 of the bulk material mixer 2 accounts for 25%-50% of the material flow rate of the first inlet 2.1, and the preferred ratio in this scheme is 35%.

[0043] Flue gas desulfurization gypsum is put into the casing through the material inlet 1.1, and is broken up by the rotating roller and discharged through the material outlet 1.2, and then discharged into the bulk material mixer 2 through the first inlet through the pipeline. A second inlet is also provided on the upper side of the bulk material mixer 2, and an outlet 2.3 is provided on the lower side of the bulk material mixer 2, and the outlet 2.3 is connected to the inlet of the bulk material conveyor 3 through a pipeline. An iron remover 4 is also installed on the upper side of the bulk material conveyor 3. The iron remover 4 is a prior art and is used to remove iron impurities in the material. The outlet of the bulk material conveyor 3 is correspondingly connected to the inlet of the gypsum wet material bin 5, and the outlet of the gypsum wet material bin 5 is connected to the inlet of the first weighing feeder 6, and the outlet of the first weighing feeder 6 is connected to the first inlet of the gypsum dryer 7.

[0044] Combination Figure 2 , Figure 3 and Figure 4 As shown, the fluidized bed dryer 7 is a horizontal structure. The gypsum dryer 7 includes a first shell 36, a first air distribution plate 37 is installed in the first shell 36, and a wind hood is evenly installed on the first air distribution plate 37. The wind hood is a prior art and is not drawn in the figure. A first wind box 38 is installed on the lower side of the first air distribution plate 37, and a fluidizing air inlet 38.1 is provided on the side wall of the first wind box 38. The fluidizing air is sent into the first wind box 38 from the fluidizing air inlet 38.1 to obtain pressure stabilization and uniform flow, and is blown into the first dense phase zone 40 from the wind hood on the first air distribution plate 37. The flow rate of the fluidizing air satisfies the empty tower standard state gas velocity of 0.3m / s at the bottom of the first dense phase zone 40 of the fluidized bed dryer 7.

[0045] The cavity of the first shell 36 on the upper side of the first air distribution plate 37 is provided with a first dilute phase zone 39 and a first dense phase zone 40, and the first dilute phase zone 39 is arranged on the upper side of the first dense phase zone 40. The transverse vertical section of the first dilute phase zone 39 is a rectangle, and the first dense phase zone 40 is a special-shaped cavity with a trapezoid 40.1 on the upper side and a rectangle 40.2 on the lower side. The horizontal length of the fluidized bed dryer 7 is 2-4 times the outlet width of the trapezoid 40.1, and the preferred embodiment is 3 times. The height of the first dense phase zone 40 is 100-180cm, and the preferred embodiment is 160cm. The height of the rectangle 40.2 is 15-25cm, and the preferred embodiment is 20cm. The trapezoid 40.1 is a structure that is wide at the top and narrow at the bottom, and the angle between the side wall of the trapezoid 40.1 and the horizontal plane is 60-65°, and the preferred embodiment is 62°.

[0046] There is a feed port 41 for the flue gas desulfurization gypsum wet material in the center of the top plate head of the first dilute phase zone 39. The distance between the feed port 41 and the side wall of the head of the fluidized bed dryer 7 is 20-50 cm, and the preferred embodiment is 35 cm. A feed pipe 42 is also connected to the first shell 36. The feed port of the feed pipe 42 is arranged on the outside of the head of the first shell 36, and the distance between the discharge port and the side wall of the head of the fluidized bed dryer 7 is 20-50 cm, and the preferred embodiment is 35 cm. The high-temperature heat carrier particles are vertically fed into the central rectangular area at the bottom of the dense phase zone 5 through the feed pipe 42. The discharge port of the feed pipe 42 is arranged in the middle position of the lower side of the first dense phase zone 40, and the distance between the discharge port and the wind cap on the first air distribution plate 37 is 5-10 cm, and the preferred embodiment is 8 cm.

[0047] A first cyclone separator 43 is also installed in the fluidized bed dryer 7. The first cyclone separator 43 is installed at the tail of the fluidized bed dryer 7. The feed port of the first cyclone separator 43 is close to the top plate of the first dilute phase zone 39. The first gas outlet 44 of the first cyclone separator 43 is arranged on the upper side of the first shell 36. The discharge port on the lower side of the first cyclone separator 43 is connected to the first discharge pipe 45. The discharge port of the first discharge pipe 45 is arranged on the outside of the first shell 36. A main discharge port 46 for heat carrier particles is also provided on the first air distribution plate 37 at the tail of the fluidized bed dryer 7. The main discharge port 46 is a single large discharge port or a plurality of parallel small discharge ports. In this solution, a plurality of parallel small discharge ports are preferred.

[0048] Under the action of fluidizing wind, the high-temperature heat carrier particles and the wet flue gas desulfurization gypsum materials in the fluidized bed dryer 7 are in a fluidized state, undergoing intense heat exchange. The free water in the flue gas desulfurization gypsum is evaporated into water vapor, and the flue gas desulfurization gypsum is dried into a dry powder state. The increase in water vapor makes the fluidization more intense, accelerating the mixing and heat exchange of the materials.

[0049] The first dense phase zone 40 is in an inverted trapezoidal shape, which is wide at the top and narrow at the bottom, forming an internal circulation flow field of "spring in the center and sinks on both sides", which is conducive to the mixing and heat exchange of materials. The angle between the trapezoidal side wall surface of the dense phase zone of the fluidized bed dryer 7 and the horizontal plane is 62°, which avoids the dead zone of non-fluidization caused by the accumulation of materials.

[0050] After the flue gas desulfurization gypsum and high-temperature heat carrier particles are fed into the head of the fluidized bed dryer 7, they gradually move toward the tail while mixing and exchanging heat. The horizontal length of the fluidized bed dryer 7 is 3 times the width of the trapezoidal outlet of its dense phase zone, which ensures that the material particles have enough residence time to complete thorough heat exchange and evaporate all the free water in the flue gas desulfurization gypsum.

[0051] In order to achieve the drying effect, the flow rate of the flue gas desulfurization gypsum wet material and the high-temperature heat carrier particles is adjusted to match the terminal temperature of the dense phase zone of the fluidized bed dryer 7 to 105-130°C, and the preferred temperature in this scheme is 120°C to achieve complete evaporation of free water.

[0052] The particle size of the flue gas desulfurization gypsum dry powder particles is several tens of μm, and the particle size of the heat carrier particles is 200-600 μm. The fluidized air exhaust gas and the evaporated water vapor carry the gypsum particles and part of the heat carrier particles into the first cyclone separator 43. Under the action of cyclone separation, the fluidized air exhaust gas and the water vapor carry the gypsum dry powder particles and are discharged from the first gas outlet 44 of the first cyclone separator 43, and the heat carrier particles are discharged from the first discharge pipe 45 of the cyclone separator. Since the particle sizes of the flue gas desulfurization gypsum dry powder and the heat carrier particles are different, the function of the first cyclone separator 43 is to ensure the fine separation of the gypsum dry powder and the heat carrier particles, improve the purity of the gypsum dry powder, and avoid the waste of heat carrier particles.

[0053] The gypsum dryer 7 is also connected to the first blower 8, the first bag receiver 9, the high-temperature heat carrier particle generator 19, the gypsum calciner 14 and the low-temperature heat carrier particle diverter 20. The first blower 8 is connected to the air inlet 38.1 of the first wind box 38. Two outlets are also provided on the low-temperature heat carrier particle diverter 20, one outlet is connected to the high-temperature heat carrier particle generator 19, and the other outlet is connected to the bulk material mixer 2.

[0054] Combination Figure 5 , Figure 6 , Figure 7 , Figure 8 and Fig. 9 As shown, the gypsum calciner 14 is a horizontal structure, and along the horizontal length direction, it includes a second shell 47. The structure of the fluidized bed calciner 14 is divided into two sections, that is, a mixing calcination area 48 and a separation discharge area 49 are provided in the second shell 47.

[0055] The mixed calcination zone 48 includes a second air distribution plate 50, on which a wind cap is installed, and the wind cap is of the prior art. A second wind box 51 is installed on the lower side of the second air distribution plate 50, and a second dilute phase zone 52 and a second dense phase zone 53 are provided in the cavity of the second shell 47 on the upper side of the second air distribution plate 50, and the second dilute phase zone 52 is arranged on the upper side of the second dense phase zone 53. The empty tower standard state gas velocity at the bottom of the second dense phase zone 53 is 0.2-0.5m / s, and the preferred embodiment of this scheme is 0.3m / s.

[0056] The second dilute phase zone 52 has a rectangular cavity in its transverse vertical section, and the second dense phase zone 53 has an upper and lower transverse vertical section, i.e., an upper trapezoidal cavity 53.1 that is wide at the top and narrow at the bottom, and a lower rectangular cavity 53.2 that is irregular in shape. The horizontal length of the mixed calcination zone 48 is 1.5-3 times the width of the upper opening of the second dense phase zone 53, and is preferably 2 times in this embodiment.

[0057] The separation and discharge area 49 includes a third air distribution plate 50.1, a third wind box 54 is installed at the lower side of the third air distribution plate 50.1, and a third rarefied phase area 55 and a third dense phase area 56 are provided in the cavity of the second shell 47 at the upper side of the third air distribution plate 50.1, and the third rarefied phase area 55 is arranged at the upper side of the third dense phase area 56. The transverse vertical section of the separation and discharge area 49 is rectangular, the third air distribution plate 50.1 and the second air distribution plate 50 are an integral structure, a wind cap is also installed on the third air distribution plate 50.1, and the second wind box 51 and the third wind box 54 are also an integral structure.

[0058] The horizontal length of the separation and discharge zone 49 is 1 / 4-1 / 8 of the horizontal length of the mixing calcination zone 48, and is preferably 1 / 6 in this embodiment. The height of the lower rectangular area of ​​the second dense phase zone 53 is 15-25 cm, and is preferably 20 cm in this embodiment. The total height of the second dense phase zone 53 is 100-180 cm, and is preferably 160 cm in this embodiment. The angle between the side wall surface of the upper trapezoidal area of ​​the second dense phase zone 53 and the horizontal plane is 60-65°, and is preferably 62° in this embodiment. The width of the separation and discharge zone 49 is the same as the width of the lower rectangular area of ​​the second dense phase zone 53.

[0059] A plurality of gypsum dry powder feed ports 57 are provided at the upper edge of the trapezoidal inclined wall on one side of the second dense phase zone 53, and the spacing between any two adjacent gypsum dry powder feed ports 57 is 20-30 cm, and the preferred embodiment of this scheme is 25 cm. A distribution pipe is installed on each gypsum dry powder feed port 57, and the distribution pipe is installed on the inclined wall of the second shell 47, and the gypsum dry powder is fed into the second dense phase zone 53 through the distribution pipe. A plurality of high-temperature heat carrier particle feed ports 58 are also provided at the upper edge of the trapezoidal inclined wall on the other side of the second dense phase zone 53, and the spacing between any two adjacent high-temperature heat carrier particle feed ports 58 is also 20-30 cm, and the preferred embodiment of this scheme is 25 cm. A distribution pipe is also installed on each high-temperature heat carrier particle feed port 58, and the distribution pipe is also installed on the inclined wall of the second shell 47. The high-temperature heat carrier particles are also fed into the second dense phase zone 53 through the distribution pipe. A fluidizing air inlet 51.1 is provided on the side wall of the second wind box 51. A heat carrier particle discharge port 59 is also provided at the tail of the separation and discharge area 49, and the heat carrier particle discharge port 59 is located on the third air distribution plate 50.1 at the tail of the separation and discharge area.

[0060] A cyclone separator 60 is also installed in the fluidized bed calciner, and the cyclone separator 60 is installed in the middle position of the horizontal length direction of the mixed calcination zone 48. The feed inlet of the cyclone separator 60 is close to the top plate position of the second freeboard zone 52, the gas outlet 61 of the cyclone separator 60 is arranged on the upper side of the second shell 47, and the discharge port on the lower side of the cyclone separator 60 is connected to the discharge pipe 62, and the discharge port of the discharge pipe 62 is arranged on the outer side of the second shell 47, which is an auxiliary outlet for heat carrier particles.

[0061] Building gypsum is produced by calcining flue gas desulfurization gypsum dry powder. The device operates as follows:

[0062] The desulfurization gypsum wet material that meets the technical requirements of GB / T 37785-2019 "Flue Gas Desulfurization Gypsum" must first undergo a drying process to become dihydrate gypsum dry powder without free water, and then be fed into the gypsum dry powder feed inlet 57 interface of the mixing calcination zone 48 of the fluidized bed calciner, and flow into the second dense phase zone 53 along the multiple distribution pipes on the inclined wall.

[0063] The heat source used for calcination is high-temperature heat carrier particles with a temperature of 750-950°C, which are fed from the high-temperature heat carrier particle feed inlet 58 on the other side wall of the mixing and calcining zone 48 of the fluidized bed calciner and also flow into the second dense phase zone 53.

[0064] Fluidizing air is fed in from the fluidizing air inlet 51.1, and is stabilized and uniformly flowed in the second wind box 51, and blown out from the hoods on the second air distribution plate 50 and the third air distribution plate 50.1. Under the action of the fluidizing air, the high-temperature heat carrier particles and the flue gas desulfurization gypsum dry powder materials in the gypsum calciner 14 are in a fluidized state, and intense heat exchange is carried out. The calcium sulfate dihydrate in the flue gas desulfurization gypsum dry powder undergoes a chemical decomposition reaction to generate hemihydrate gypsum and type III anhydrous gypsum, and release water vapor. The increase in water vapor makes the fluidization more intense, accelerates the mixing and heat exchange of materials, and because the particle size of the gypsum dry powder particles is only a few tens of microns, the calcination process is completed quickly.

[0065] The dense phase area of ​​the mixing and calcining zone 48 of the fluidized bed calciner is in an inverted trapezoidal shape, which is wide at the top and narrow at the bottom, forming an internal circulation flow field of "a spring in the center and sinks on both sides", which is conducive to the mixing and heat exchange of materials. The angle between the trapezoidal side wall surface of the second dense phase area 53 of the mixing and calcining zone 48 of the fluidized bed calciner and the horizontal plane is 60-65°, and the preferred angle in this solution is 62°, which avoids the accumulation of materials and the occurrence of non-fluidized dead zones.

[0066] The particle diameter of the flue gas desulfurization gypsum dry powder is less than tens of microns, with a large specific surface area and fast heat transfer speed, which can quickly complete the decomposition. The multi-point distribution method makes the materials more evenly mixed in the second dense phase zone 53, the bed temperature is stably controlled, the reaction rate is high, and the product quality is good.

[0067] In order to achieve the calcination effect, the flow rate of flue gas desulfurization gypsum dry powder and high-temperature heat carrier particles is adjusted to match to meet the terminal temperature of the dense phase zone of the fluidized bed calciner of 170-230°C, preferably 200°C in this scheme, to achieve complete decomposition of calcium sulfate dihydrate.

[0068] The particle size of the semi-hydrated gypsum and anhydrous gypsum dry powder particles generated by the decomposition reaction is several μm to tens of μm, and the particle size of the heat carrier particles is 200-600 μm, and the preferred size in this solution is 450 μm. The fluidized air exhaust gas and the water vapor generated by the decomposition reaction carry the semi-hydrated gypsum, anhydrous gypsum dry powder particles and part of the heat carrier particles into the cyclone separator 60. Under the action of the cyclone separation, the fluidized air exhaust gas and the water vapor carry the semi-hydrated gypsum and anhydrous gypsum dry powder particles and are discharged from the gas outlet 61 of the cyclone separator, and the heat carrier particles are discharged from the discharge pipe 62 of the cyclone separator.

[0069] The fluidized air velocity in the mixed calcination zone 48 of the fluidized bed calciner is not enough to blow all the heat carrier particles to the cyclone separator 60, and most of the heat carrier particles will flow to the separation and discharge zone 49. There is no material inlet for gypsum dry powder and heat carrier particles installed in the separation and discharge zone 49, and a structure with a rectangular horizontal vertical section is adopted. In this way, the fluidized air blown up from the third air distribution plate 50.1 can maintain a relatively high wind speed in the third dense phase zone 56 and the third dilute phase zone 55 at the top. The material particles flowing from the second dense phase zone 53 to the third dense phase zone 56 are mainly heat carrier particles, mixed with a small amount of gypsum dry powder particles. Under the action of the high wind speed in the third dense phase zone 56, since the particle size of the gypsum dry powder particles is several μm to tens of μm, and the particle size of the heat carrier particles is 200-600 μm, the gypsum particles in the mixed particles are more easily blown to the third dilute phase zone 55, thereby realizing the separation of gypsum particles and heat carrier particles. Due to the action of the induced draft fan, the inlet of the cyclone separator 60 is a low-pressure area, and the fluidized air exhaust gas will carry the gypsum particles in the third dilute phase area 55 into the cyclone separator 60, while the heat carrier particles in the third dense phase area 56 are discharged from the heat carrier particle discharge port 59 without containing gypsum particles.

[0070] The first bag receiver 9 is also connected to the gypsum raw material bin 10 and the exhaust pipe 12, the gypsum raw material bin 10 is connected to the second weighing feeder 13, and the second weighing feeder 13 is connected to the gypsum calciner 14. A first pipeline 28 is connected between the first bag receiver 9 and the exhaust pipe 12, and the first induced draft fan 11 is connected to the first pipeline 28.

[0071] The gypsum calciner 14 is also connected to the second blower 15, the second bag collector 16 and the high-temperature heat carrier particle generator 19. The second bag collector 16 is also connected to the exhaust pipe 12. A second pipe 29 is connected between the second bag collector 16 and the exhaust pipe 12, and a second induced draft fan 18 is connected to the second pipe 29. The second bag collector 16 is connected to the gypsum clinker bin 17, and the gypsum clinker bin 17 is connected to the clinker cooler 21. The clinker cooler 21 is also provided with a discharge port 21.2 for discharging finished building gypsum dry powder, a cooling medium inlet 21.3 and a cooling medium outlet 21.4.

[0072] The first valve 23 is connected to the first pipe 28, the first pipe 28 is connected to the waste heat recovery device 22 through the third pipe 30, the third pipe 30 is connected to the front side of the first valve 23, and the third valve 25 is connected to the third pipe 30. The second valve 24 is connected to the second pipe 29, the second pipe 29 is connected to the waste heat recovery device 22 through the fourth pipe 31, the fourth pipe 31 is connected to the front side of the second valve 24, and the fourth valve 26 is connected to the fourth pipe 31. The waste heat recovery device 22 is also connected to the exhaust pipe 12 through the fifth pipe 32, the fifth valve 27 is connected to the fifth pipe 32, and a condensed water outlet 33, a cold water inlet 34 and a hot water outlet 35 are also provided.

[0073] This device operates as follows: the desulfurized gypsum wet material that meets the technical requirements of GB / T 37785-2019 "Flue Gas Desulfurization Gypsum" has a free water content of 10-15%, and the solid matter is mainly calcium sulfate dihydrate (CaSO4•2H2O). The desulfurized gypsum wet material is stored in the gypsum yard, transported by a forklift to the side of the wet material dispersing machine 1 and poured into the inlet 1.1 of the wet material dispersing machine 1. The wet material dispersing machine 1 breaks up the agglomerated gypsum wet material into loose crushed materials and discharges them from the outlet 1.2 and enters the bulk material mixer 2. At the same time, the low-temperature heat carrier particles discharged by the gypsum dryer 7 are also sent to the bulk material mixer 2. After the two materials are mixed, the moisture content and adhesion of the gypsum wet material can be effectively reduced, which is beneficial to material transportation and prevents adhesion and clogging of equipment.

[0074] The mixed desulfurized gypsum wet material is sent to the gypsum wet material silo 5 for buffering by the bulk material conveyor 3 . The metal impurities in the material are removed by the iron remover 4 during the transportation process. The gypsum wet material in the gypsum wet material silo 5 is sent to the gypsum dryer 7 by the first weighing feeder 6 .

[0075] The gypsum dryer 7 adopts a fluidized bed structure. The first blower 8 blows air into the dryer through the air distribution plate as fluidizing wind to fluidize the bed material. The first weighing feeder 6 feeds wet gypsum into the fluidized bed dryer 7, and also feeds high-temperature heat carrier particles from the high-temperature heat carrier particle generator 19. The temperature of the heat carrier particles is 750-950°C. Under the action of the fluidizing wind, the wet gypsum and the high-temperature heat carrier particles are in a fluidized state and undergo intense heat exchange. The free water in the wet gypsum is evaporated into water vapor. The generation of water vapor makes the bed material fluidized more intensely, which is conducive to mixing and heat exchange. The desulfurized gypsum wet material is dried to become desulfurized gypsum dry powder.

[0076] Under the action of cyclone separation, the heat carrier particles, fluidized air exhaust gas and water vapor carry the gypsum dry powder particles and are discharged from the gypsum dryer 7 to the first bag receiver 9. After releasing the heat, the temperature of the heat carrier particles is reduced to 120°C and they are sent from the gypsum dryer 7 to the low-temperature heat carrier particle diverter 20.

[0077] The fluidized air exhaust gas and water vapor of the gypsum dryer 7 carry the gypsum dry powder particles to the first bag collector 9 to complete gas-solid separation. The gypsum dry powder particles are solid materials, which are discharged from the first bag collector 9 and sent to the gypsum raw material bin 10. The fluidized air exhaust gas and water vapor are in gas state, which are discharged from the first bag collector 9 and sent to the exhaust pipe 12 under the action of the first induced draft fan 11. In order to recover heat, a first valve 23 is installed on the connecting pipe.

[0078] The solid powder in the gypsum raw material bin 10 does not contain free water, and its solid material is mainly composed of calcium sulfate dihydrate (CaSO4•2H2O), which contains crystal water and is called "raw material". The gypsum raw material is fed into the gypsum calciner 14 by the second weighing feeder 13.

[0079] The gypsum calciner 14 also adopts a fluidized bed structure. The second blower 15 blows air into the calciner through the air distribution plate as fluidizing wind to fluidize the bed material. The second weighing feeder 13 feeds gypsum raw material dry powder into the fluidized bed calciner 14, and also feeds high-temperature heat carrier particles from the high-temperature heat carrier particle generator 19. The temperature of the heat carrier particles is 750-950°C. Under the action of the fluidizing wind, the gypsum raw material dry powder and the high-temperature heat carrier particles are in a fluidized state and undergo intense heat exchange. The gypsum raw material undergoes a chemical decomposition reaction, and the dihydrate gypsum is decomposed into hemihydrate gypsum, while releasing water vapor. If the bed temperature of the gypsum calciner is increased, type III anhydrous gypsum can also be generated. The generation of water vapor causes the bed material to be violently fluidized, accelerates mixing and heat exchange, and all the dihydrate gypsum is calcined into hemihydrate gypsum or type III anhydrous gypsum.

[0080] The chemical reaction equation for this process is:

[0081] CaSO4•2H2O=CaSO4•1 / 2H2O+1.5H2O

[0082] CaSO4•1 / 2H2O=CaSO4+0.5H2O

[0083] Since the particle size of hemihydrate gypsum or type III anhydrous gypsum is only tens of μm, and the particle size of the heat carrier particles selected in the present invention is 200-600 μm, under the action of cyclone separation, the fluidized air exhaust gas and water vapor carry the hemihydrate gypsum or type III anhydrous gypsum particles and are discharged from the fluidized bed calciner 14 and sent to the second bag receiver 16. After releasing the heat, the temperature of the heat carrier particles is reduced to 200°C, and they are discharged from the gypsum calciner 14 and sent to the gypsum dryer 7, and the heat of the heat carrier particles is further used to dry the wet gypsum.

[0084] The gypsum calciner 14 is different from the gypsum dryer 7 in structural details, because the wet material mass and high-temperature heat carrier particles are mixed for heat exchange in the gypsum dryer 7, while the fine powder particles of the gypsum raw material and high-temperature heat carrier particles are mixed for heat exchange in the gypsum calciner 14, and the heat exchange coefficient and heat exchange time are different.

[0085] The fluidized air exhaust gas and water vapor of the gypsum calciner 14 carry the semi-hydrated gypsum or type III anhydrous gypsum dry powder particles to the second bag receiver 16 to complete gas-solid separation. The semi-hydrated gypsum or type III anhydrous gypsum dry powder particles are solid materials, which are discharged from the first outlet 16.2 of the second bag receiver 16 and sent to the gypsum clinker bin 17. The fluidized air exhaust gas and water vapor are in a gas state, which are discharged from the second outlet 16.3 of the second bag receiver 16 and sent to the exhaust pipe 12 under the action of the second induced draft fan 18. In order to recover heat, a second valve 24 is installed on the connecting pipe.

[0086] The solid powder in the gypsum clinker bin 17 is hemihydrate gypsum or type III anhydrous gypsum dry powder particles, and its temperature is 200°C. It is sent to the clinker cooler 21 and is cooled to below 50°C under the action of the cooling medium. It can be packaged or transported to the user by a powder tanker.

[0087] The low-temperature heat carrier particles discharged from the gypsum dryer 7 have a temperature of 120°C and are sent to the low-temperature heat carrier particle splitter 20, which is divided into two outputs. The first branch returns to the high-temperature heat carrier particle generator 19, and after absorbing the heat released by the fuel in the furnace, the temperature rises to 750-950°C and is recycled. The second branch is sent to the bulk material mixer 2 to mix with the gypsum wet material. Since the low-temperature heat carrier particles are completely dry materials, the material flow ratio of the low-temperature heat carrier particles to the gypsum wet material is controlled to be 30%, which can effectively reduce the moisture content of the mixed materials, prevent adhesion or blockage of the equipment during material transportation, and improve the reliability and stability of operation.

[0088] The gypsum dryer 7 and the gypsum calciner 14 both use a low-speed fluidized bed, the empty tower standard gas velocity at the bottom of the dense phase zone of the fluidized bed is 0.3 m / s, the fluidizing air consumption is low, and the water vapor content in the outlet gas of the gypsum dryer 7 and the gypsum calciner 14 is above 60%, and the latent heat of vaporization of the water vapor can be recovered.

[0089] Close the first valve 23 and the second valve 24, open the third valve 25 and the fourth valve 26, send the exhaust gas rich in water vapor to the waste heat recovery device 22, and introduce cold water from the cold water inlet 34 of the waste heat recovery device 22. The water vapor in the exhaust gas condenses in the waste heat recovery device 22, releasing heat. The water vapor condenses into water, and the heat heats the cold water into hot water. The hot water is sent out from the hot water outlet 35 of the waste heat recovery device 22 and sent to the user for use. The condensed water is discharged from the condensed water outlet 33. The non-condensable gas in the exhaust gas is sent to the exhaust pipe 12 for discharge. In this way, the heat in the exhaust gas is recovered and hot water is generated, which can be used for heating or sanitary bathing.

[0090] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the utility model and are not used to limit the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A device for producing building gypsum using flue gas desulfurization gypsum, characterized in that: The invention comprises a wet material dispersing machine (1), wherein the wet material dispersing machine (1) is connected to a bulk material mixer (2), the bulk material mixer (2) is connected to a bulk material conveyor (3), the bulk material conveyor (3) is connected to a gypsum wet material bin (5), the gypsum wet material bin (5) is connected to a gypsum dryer (7) via a first weighing feeder (6), the gypsum dryer (7) is also connected to a first air blower (8), a first bag receiver (9), a high-temperature heat carrier particle generator (19), a gypsum calciner (14) and a low-temperature heat carrier particle diverter (20), and the low-temperature heat carrier particle diverter (20) is also connected to the bulk material mixer (2) and the high-temperature heat carrier particle generator (19); The first bag receiver (9) is also connected to the gypsum raw material bin (10) and the exhaust pipe (12); the gypsum raw material bin (10) is connected to the second weighing feeder (13); and the second weighing feeder (13) is connected to the gypsum calciner (14); The gypsum calciner (14) is also connected to a second air blower (15), a second bag collector (16) and a high-temperature heat carrier particle generator (19); the second bag collector (16) is also connected to an exhaust pipe (12); the second bag collector (16) is connected to a gypsum clinker bin (17); and the gypsum clinker bin (17) is connected to a clinker cooler (21).

2. The device for producing building gypsum using flue gas desulfurization gypsum according to claim 1, characterized in that: A first pipe (28) is connected between the first bag collector (9) and the exhaust pipe (12), and a first induced draft fan (11) is connected to the first pipe (28); a second pipe (29) is connected between the second bag collector (16) and the exhaust pipe (12), and a second induced draft fan (18) is connected to the second pipe (29).

3. The device for producing building gypsum using flue gas desulfurization gypsum according to claim 2, characterized in that: The first pipe (28) is connected to a first valve (23); the first pipe (28) is connected to a waste heat recovery device (22) via a third pipe (30); the third pipe (30) is connected to the front side of the first valve (23); and the third pipe (30) is connected to a third valve (25); The second pipe (29) is connected to a second valve (24); the second pipe (29) is connected to a waste heat recovery device (22) via a fourth pipe (31); the fourth pipe (31) is connected to the front side of the second valve (24); and the fourth pipe (31) is connected to a fourth valve (26); The waste heat recovery device (22) is also connected to the exhaust pipe (12) via a fifth pipe (32), a fifth valve (27) is connected to the fifth pipe (32), and a condensate outlet (33), a cold water inlet (34) and a hot water outlet (35) are also provided on the waste heat recovery device (22).

4. The device for producing building gypsum using flue gas desulfurization gypsum according to claim 1, characterized in that: An iron remover (4) is also installed on the bulk material conveyor (3).

5. The device for producing building gypsum using flue gas desulfurization gypsum according to claim 1, characterized in that: The gypsum dryer (7) comprises a first shell (36), a first air distribution plate (37) is installed in the first shell (36), a first wind box (38) is installed on the lower side of the first air distribution plate (37), and a first rarefied phase zone (39) and a first dense phase zone (40) are provided in the cavity of the first shell (36) on the upper side of the first air distribution plate (37), and the first rarefied phase zone (39) is arranged on the upper side of the first dense phase zone (40); A feed port (41) for the flue gas desulfurization gypsum wet material is provided in the center of the top plate head of the first dilute phase zone (39), and a feed pipe (42) is also connected to the first shell (36). The feed port of the feed pipe (42) is arranged outside the head of the first shell (36), and the discharge port of the feed pipe (42) is arranged in the middle position of the lower side of the first dense phase zone (40). A first cyclone separator (43) is also installed in the fluidized bed dryer (7). The first cyclone separator (43) is installed at the tail of the fluidized bed dryer (7). The feed inlet of the first cyclone separator (43) is close to the top plate of the first dilute phase zone (39). The first gas outlet (44) of the first cyclone separator (43) is arranged on the upper side of the first shell (36). The discharge port on the lower side of the first cyclone separator (43) is connected to the first discharge pipe (45). The discharge port of the first discharge pipe (45) is arranged on the outside of the first shell (36). A main discharge port (46) for heat carrier particles is also provided on the first air distribution plate (37) at the tail of the fluidized bed dryer (7).

6. The device for producing building gypsum using flue gas desulfurization gypsum according to claim 1, characterized in that: The gypsum calciner (14) comprises a second shell (47), and a mixing calcination area (48) and a separation discharge area (49) are provided in the second shell (47); The mixed calcination zone (48) comprises a second air distribution plate (50), a second wind box (51) is installed on the lower side of the second air distribution plate (50), and a second rarefied phase zone (52) and a second dense phase zone (53) are provided in the cavity of the second shell (47) on the upper side of the second air distribution plate (50), and the second rarefied phase zone (52) is arranged on the upper side of the second dense phase zone (53); The separation and discharge area (49) comprises a third air distribution plate (50.1), a third wind box (54) is installed on the lower side of the third air distribution plate (50.1), and a third dilute phase area (55) and a third dense phase area (56) are provided in the cavity of the second shell (47) on the upper side of the third air distribution plate (50.1), and the third dilute phase area (55) is arranged on the upper side of the third dense phase area (56); A group of gypsum dry powder feed ports (57) are provided on one side of the second dense phase zone (53), and a group of high-temperature heat carrier particle feed ports (58) are provided on the other side; and a heat carrier particle discharge port (59) is provided on the third air distribution plate (50.1); A second cyclone separator (60) is also installed in the fluidized bed calciner. The feed inlet of the second cyclone separator (60) is close to the top plate of the second freeboard zone (52). The second gas outlet (61) of the second cyclone separator (60) is arranged on the upper side of the second shell (47). The discharge port on the lower side of the second cyclone separator (60) is connected to the second discharge pipe (62). The discharge port of the second discharge pipe (62) is arranged on the outer side of the second shell (47).

7. The device for producing building gypsum using flue gas desulfurization gypsum according to claim 1, characterized in that: The empty tower standard gas velocity at the bottom of the dense phase zone of the fluidized bed of the gypsum dryer (7) and the gypsum calciner (14) is 0.2-0.5 m / s.

8. The device for producing building gypsum using flue gas desulfurization gypsum according to claim 1, characterized in that: The fuel of the high-temperature heat carrier particle generator (19) is solid fuel or gas fuel, the particle size of the high-temperature heat carrier particles used is in the range of 200 μm-600 μm, and the temperature of the produced high-temperature heat carrier particles is 750-950°C.

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