Integrated device system for pelletizing, drying and thermal decomposition of industrial byproduct gypsum

Abstract

The utility model provides an integrated device system for pelletizing, drying and thermal decomposition of industrial byproduct gypsum. The integrated device system comprises a rolling type drying device, a rolling type pelletizing device, a drying device, a reduction calcining device, a braising groove and a cooling device which are connected in sequence, and gas pipelines of the braising tank, the drying device and the rolling type drying device are communicated. According to the integrated device system provided by the utility model, materials are uniformly mixed, the stacking density of the materials is improved, the thermal decomposition reaction efficiency is improved, the problem of dust raising during calcination is solved, the reduction calcination environment is improved by arranging the braising groove, meanwhile, gradient utilization of energy of a thermal decomposition process is realized, and the energy consumption and the process cost of the system are reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of solid waste treatment, and relates to a treatment system for industrial by-product gypsum, in particular to an integrated device system for pelletizing, drying and thermal decomposition of the industrial by-product gypsum. Background Art

[0002] Gypsum is a common solid waste residue in industrial production, mostly used as a cement additive. Its output is high but its utilization rate is insufficient. Large amounts of accumulation occupy valuable land resources. In addition, the phosphorus, fluorine and other elements in it also have an impact on the ecological environment. Therefore, how to effectively utilize industrial by-product gypsum has become an urgent problem to be solved.

[0003] Gypsum is thermally decomposed to obtain sulfuric acid and lime. Sulfuric acid can be directly reused or sold, and lime is a bulk commodity with a broad market. For example, CN116750984A discloses a method and system for treating by-product gypsum in the production of sulfuric acid and cement clinker. Existing gypsum thermal decomposition technology has the following technical problems: First, gypsum thermal decomposition relies on high temperature conditions and has high energy consumption, especially in the decomposition process in the gypsum rotary kiln, where the energy consumption problem is particularly prominent; Second, existing thermal decomposition technology mainly refers to cement clinker calcination technology, and the material is prone to ring formation, the gas SO2 concentration is low, the amount of dust is extremely large, and impurities and incompletely decomposed substances in the gypsum are easily accumulated inside the equipment, causing equipment blockage, affecting production efficiency and continuity, and the equipment design still needs to be optimized; Third, the product lime is mainly used as a cement raw material, and its added value is relatively low, which is not enough to support the high cost operation of the entire process, so the overall process cost needs to be controlled. The above problems have seriously troubled the further use and promotion of by-product gypsum thermal decomposition technology. Therefore, it is necessary to provide an industrial by-product gypsum integrated processing system to optimize the existing gypsum thermal decomposition process. Utility Model Content

[0004] The purpose of the utility model is to provide an integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum, so as to solve the dust and energy consumption problems in the thermal decomposition process of industrial by-product gypsum and improve the reaction efficiency of thermal decomposition.

[0005] In order to achieve the purpose of this utility model, the utility model adopts the following technical solutions:

[0006] The utility model provides an integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum, which comprises:

[0007] A rolling drying device, a roller-pressing pelletizing device, a drying device, a reduction calcining device, a stewing tank and a cooling device are connected in sequence;

[0008] The gas pipelines of the stewing tank, the drying device and the rolling drying device are connected.

[0009] The integrated device system provided by the present invention pre-mixes gypsum and coke powder and other materials into balls through a rolling drying device and a roller-pressing ball-forming device, and then performs reduction calcination, which directly avoids the problem of easy dust emission due to the low bulk density of gypsum during the calcination process. The bulk density of the material after extrusion increases by 2-3 times, and the gypsum and coke powder are mixed more evenly, which is more conducive to solid-solid reaction. At the same time, the filling amount during the calcination process can be greatly improved, the processing capacity per unit volume is greatly improved, and the dust content of the gas generated after thermal decomposition is greatly reduced, which reduces the operating pressure of the subsequent dust removal equipment and is more conducive to the step-by-step utilization of heat. A stewing tank is set at the rear end of the reduction calcination device to effectively extend the decomposition time and control the amount of secondary air entering. The burner of the reduction calcination device and the secondary air preheated by the cooling device jointly constitute the gas phase environment of reduction calcination, which can provide the required heat for calcination and effectively prevent oxygen from entering and form a reducing atmosphere, thereby enhancing the reliability of the reduction environment of gypsum reduction thermal decomposition. At the same time, the high-temperature hot air generated by the heat exchange of the cooling device is reused for material drying, effectively realizing the cascade utilization of energy and reducing system energy consumption and process costs.

[0010] In the present invention, the rolling drying device, roller-pressing pelletizing device, drying device, reduction calcining device and cooling device all adopt equipment commonly used in this field. The rolling drying device realizes the functions of material rolling and drying, the roller-pressing pelletizing device realizes material roller forming, the drying device realizes material drying, the reduction calcining device realizes calcination and decomposition of gypsum, and the cooling device realizes material cooling. The present invention does not make specific limitations on their structures.

[0011] In the present invention, the structure of the stewing tank is a closed container, and the interior of the stewing tank is built with refractory and wear-resistant materials, so that the high-temperature materials discharged from the reduction calcination device can stay here for more than 5 hours, which plays a role in extending the reaction time and improving the reaction yield.

[0012] Preferably, the integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum further comprises: a dust removal device, which is respectively connected to the rolling drying device and the roller-pressing pelletizing device.

[0013] Preferably, a gas sealing structure is provided at the tail end of the reduction calcination device.

[0014] In the present invention, the gas sealing structure is a nitrogen labyrinth seal, and its working principle is: nitrogen with positive pressure introduced from the outside is used as protective gas to pass into the seal, maintaining a positive pressure state, and the nitrogen eventually enters the reduction calcining device to prevent external air from being sucked into the rotary kiln, thereby ensuring that the rotary kiln is in a reducing atmosphere.

[0015] Preferably, the gas outlet of the reduction calcination device is connected to a sulfuric acid preparation system.

[0016] Preferably, the integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum further comprises: a material conveying unit.

[0017] Preferably, the material conveying unit includes a mixing conveyor, and the rolling drying device and the roller-pressing pelletizing device are connected via the mixing conveyor.

[0018] Preferably, the material conveying unit includes a mixing elevator, and the roller-type pelletizing device and the belt drying device are connected via the mixing elevator.

[0019] Preferably, the material conveying unit comprises a lime conveyor, and the lime conveyor is connected to the cooling device.

[0020] Preferably, the reduction calcination device is a reduction calcination kiln.

[0021] Preferably, the drying device is a belt dryer.

[0022] Preferably, the cooling device is a grate cooler.

[0023] The utility model also provides an integrated treatment method for pelletizing, drying and thermal decomposition of industrial by-product gypsum, which uses an integrated device system for pelletizing, drying and thermal decomposition of the industrial by-product gypsum. The integrated treatment method is as follows:

[0024] Gypsum and coke are put into the rolling drying device, where the materials are rolled to achieve efficient mixing and complete drying. At the same time, the dust generated during the process enters the dust removal device for dust removal;

[0025] The mixed materials are conveyed by the mixing conveyor to the mixing roller-pressing pelletizing device. At the same time, the dust generated by the dust removal device is also recycled. The materials are compressed and pelletized by the rollers of the roller-pressing pelletizing device to obtain roller-pressed balls.

[0026] The roller-pressed balls are fed to the drying device through the mixing elevator, where they are dried.

[0027] The dried roller-pressed balls enter the reduction calcination device for thermal decomposition to obtain SO2 gas and lime. The SO2 gas is discharged from the gas outlet of the reduction calcination device and enters the sulfuric acid preparation system for the preparation of sulfuric acid. The lime enters the stewing tank to extend the reaction time.

[0028] The lime enters the cooling device for cooling. Air is introduced into the cooling device to complete the cooling of the lime. The high-temperature hot air generated by the heat exchange is discharged and enters the drying device and the rolling drying device in turn for drying the mixed material, realizing energy utilization. The cooled lime is transported to the subsequent process by the lime conveyor.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The integrated device system provided by the utility model realizes uniform mixing of materials through premixing and pelletizing of materials, improves the stacking density of materials, improves the efficiency of thermal decomposition reaction, and solves the problem of calcination dust. The calcination environment is optimized and reduced by setting a stewing tank. At the same time, the energy cascade utilization of the thermal decomposition process is realized, thereby reducing the system energy consumption and process costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of the structure of an integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum provided in Example 1;

[0032] Among them: 1- gypsum rolling mixing dryer; 2- mixing conveyor; 3- mixing roller pelletizing machine; 4- rolling drying dust collector; 5- mixing elevator; 6- roller ball belt dryer; 7- reduction calcining kiln; 71- reduction calcining kiln burner; 72- reduction calcining kiln gas sealing structure; 8- mixing trough; 9- grate cooler; 10- lime conveyor; 11- sulfuric acid preparation system. DETAILED DESCRIPTION

[0033] It should be understood that, in the description of the present invention, the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship 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 device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0034] It should be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "disposed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0035] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0036] Example 1

[0037] This embodiment provides a Figure 1 The integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum shown in the figure comprises:

[0038] The gypsum rolling mixing dryer 1, the mixing conveyor 2, the mixing roller pelletizing machine 3, the mixing elevator 5, the roller ball belt dryer 6, the reduction calcining kiln 7, the stewing trough 8, the grate cooler 9 and the lime conveyor 10 are connected in sequence.

[0039] The gas outlet of the stewing tank 8 is connected to the gas inlet of the roller-pressed ball belt dryer 6, and the gas outlet of the roller-pressed ball belt dryer 6 is connected to the gas inlet of the gypsum rolling mixing dryer 1.

[0040] The rolling drying dust collector 4 is connected to the gypsum rolling mixing dryer 1 and the mixing roller pelletizing machine 3 respectively.

[0041] A nitrogen sealing structure 72 is provided at the tail end of the reduction calcining kiln 7 .

[0042] The kiln head gas outlet of the reduction calcining kiln 7 is connected to the sulfuric acid preparation system 11.

[0043] This embodiment also provides an integrated treatment method for pelletizing, drying, and thermal decomposition of industrial by-product gypsum. The integrated treatment method uses an integrated device system for pelletizing, drying, and thermal decomposition of the industrial by-product gypsum. The integrated treatment method is as follows:

[0044] (1) Gypsum and coke are put into the gypsum rolling and mixing dryer 1, and the materials are rolled in the gypsum rolling and mixing dryer 1 to achieve efficient mixing and complete drying. At the same time, the dust generated in the process enters the rolling and drying dust collector 4 for dust removal;

[0045] (2) The mixed material is conveyed by the mixing conveyor 2 to the mixing roller pelletizing machine 3. At the same time, the dust generated by the rolling drying dust collector 4 is also recycled. The material is compressed and pelletized by the roller forming of the mixing roller pelletizing machine 3 to obtain roller-pressed balls.

[0046] (3) The roller-pressed balls are fed to the roller-pressed ball belt dryer 6 via the mixing elevator 5, and the roller-pressed balls are dried on the mesh belt of the roller-pressed ball belt dryer 6;

[0047] (4) The dried roller-pressed balls enter the reduction calcining kiln 7 for thermal decomposition to obtain SO2 gas and lime. The SO2 gas is discharged from the gas outlet of the kiln head and enters the sulfuric acid preparation system 11 for the preparation of sulfuric acid. The lime enters the stewing tank 8 to extend the reaction time.

[0048] (5) The lime enters the grate cooler 9 for cooling. Air is introduced into the grate cooler 9 to complete the cooling of the lime. The high-temperature hot air generated by the heat exchange is discharged and enters the roller ball belt dryer 6 and the gypsum rolling mixing dryer 1 in turn for drying the mixed material, realizing energy utilization. The cooled lime is transported to the subsequent process by the lime conveyor 10.

[0049] In summary, the integrated device system provided by the utility model realizes uniform mixing of materials through premixing and pelletizing of materials, improves the stacking density of materials, improves the efficiency of thermal decomposition reaction, and solves the problem of calcination dust. The reduction calcination environment is improved by setting a stewing trough. At the same time, the energy cascade utilization of the thermal decomposition process is realized, thereby reducing the system energy consumption and process costs.

[0050] The above description is only a specific implementation method of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present invention fall within the protection scope and disclosure scope of the present invention.

Claims

1. An integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum, characterized in that: The integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum includes: A rolling drying device, a roller-pressing pelletizing device, a drying device, a reduction calcining device, a stewing tank and a cooling device are connected in sequence; The gas pipelines of the stewing tank, the drying device and the rolling drying device are connected.

2. The integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum according to claim 1, characterized in that: The integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum further comprises a dust removal device, which is respectively connected to the rolling drying device and the roller-pressing pelletizing device.

3. The integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum according to claim 1, characterized in that: A gas sealing structure is provided at the tail end of the reduction calcination device.

4. The integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum according to claim 1, characterized in that: The gas outlet of the reduction calcination device is connected to a sulfuric acid preparation system.

5. The integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum according to claim 1, characterized in that: The integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum also includes a material conveying unit.

6. The integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum according to claim 5, characterized in that: The material conveying unit includes a mixing conveyor, and the rolling drying device and the roller-pressing pelletizing device are connected via the mixing conveyor.

7. The integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum according to claim 5, characterized in that: The material conveying unit includes a mixing elevator, and the roller-pressed pelletizing device and the belt drying device are connected via the mixing elevator.

8. The integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum according to claim 5, characterized in that: The material conveying unit includes a lime conveyor, and the lime conveyor is connected to the cooling device.

9. The integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum according to claim 1, characterized in that: The reduction calcination device is a reduction calcination kiln.

10. The integrated device system for pelletizing, drying and thermal decomposition of industrial by-product gypsum according to claim 1, characterized in that: The drying device is a belt dryer; The cooling device is a grate cooler.

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