Gypsum dehydration system

Abstract

The utility model provides a gypsum dehydration system, which relates to the technical field of desulfurization wastewater treatment, and comprises a gypsum cyclone, a rapid settling tank and a middle water tank which are sequentially connected through an overflow port, a vacuum belt dehydrator is arranged below the gypsum cyclone and the rapid settling tank, a sand settling nozzle is arranged in the gypsum cyclone, the rapid settling tank is provided with a plurality of mud buckets, and the mud buckets are arranged in the middle water tank. The gypsum cyclone and a bottom discharge port of each mud bucket are connected to the upper side of the vacuum belt dehydrator and are sequentially arranged along the rotating direction of an upper-layer belt of the vacuum belt dehydrator, and the vacuum belt dehydrator is connected with a vacuum pump; the middle water tank is connected with a wastewater cyclone through a water tank delivery pump, and a bottom outlet of the wastewater cyclone is connected with a rapid settling tank; desulfurization slurry discharged from a desulfurization tower is introduced into a gypsum cyclone, and gypsum is distributed on a vacuum belt dehydrator according to the particle size of big end down through step-by-step treatment, and is rapidly dehydrated under the action of a vacuum pump. Gypsum gaps are large in bottom and small in top, blocking is not prone to occurring in the dehydration process, and the dehydration efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of desulfurization wastewater treatment, in particular to a gypsum dehydration system. Background Art

[0002] Limestone / gypsum wet desulfurization is widely used and is the primary desulfurization technology for thermal power plants. The main energy consumption for desulfurization system operation includes power consumption of the induced draft fan, circulating pump, oxidation fan, and gypsum dehydration system. Gypsum dehydration accounts for approximately 10-15% of total power consumption.

[0003] Desulfurized gypsum, a byproduct of the desulfurization process, is produced in large quantities. Its primary applications include medical gypsum, building material gypsum, and cement sintering raw materials. The desulfurized slurry is treated in a cyclone, belt dehydrator, and integrated desulfurization wastewater treatment equipment to produce calcium sulfate dihydrate (CaSO4·2H2O) with a content of ≥93%.

[0004] Therefore, how to reduce the power consumption of gypsum dehydration, reduce the moisture content of gypsum and improve the quality of gypsum are the main factors in reducing the cost of gypsum dehydration. Utility Model Content

[0005] In view of the technical problems existing in the background technology, the utility model patent provides a gypsum dehydration system, which uses a gypsum cyclone machine and a rapid sedimentation box to distinguish the particle size of gypsum in desulfurization wastewater, and spreads the gypsum with large particles at the bottom and small particles at the top on a vacuum belt dehydrator. Then, when the vacuum pump connected to the vacuum belt dehydrator dehydrates the gypsum on the upper side of the vacuum belt dehydrator, air passes through the gypsum from top to bottom to take away moisture. Since the gaps in the gypsum on the lower side are larger, air is easier to extract and is not easy to get clogged. The vacuum suction force can be efficiently and fully utilized to improve the dehydration efficiency, reduce the vacuum degree and the air extraction volume, and achieve low-cost operation.

[0006] To achieve the above-mentioned object, the utility model provides a gypsum dehydration system, comprising: a gypsum cyclone, a rapid sedimentation tank, and an intermediate water tank connected in sequence via an overflow port; a vacuum belt dehydrator is provided below the gypsum cyclone and the rapid sedimentation tank; a sand settling spout is provided in the gypsum cyclone; the rapid sedimentation tank is provided with multiple mud hoppers; the bottom discharge ports of the gypsum cyclone and each mud hopper are connected to the upper belt of the vacuum belt dehydrator, and are arranged in sequence along the rotation direction of the upper belt of the vacuum belt dehydrator; the vacuum belt dehydrator is connected to a vacuum pump; the intermediate water tank is connected to the wastewater cyclone via a water tank delivery pump; the bottom discharge port of the wastewater cyclone is connected to the rapid sedimentation tank;

[0007] The desulfurization slurry discharged from the desulfurization tower is connected to the gypsum cyclone, and large-particle gypsum is precipitated through the sand settling mouth and discharged to the vacuum belt dehydrator from the bottom outlet. The overflow enters the rapid sedimentation box, and the gypsum in the overflow is precipitated by each mud bucket in order from large to small according to the particle size, and discharged to the vacuum belt dehydrator. As the vacuum belt dehydrator rotates, the small-particle gypsum covers the large-particle gypsum, and the vacuum pump dehydrates the gypsum on the upper belt of the vacuum belt dehydrator. The dehydrated gypsum leaves the vacuum belt dehydrator at the end of the rotation direction of the upper belt of the vacuum belt dehydrator.

[0008] As a further improvement of the present invention, the rapid sedimentation box adopts a horizontal flow sedimentation mode and is provided with a first mud hopper and a second mud hopper.

[0009] As a further improvement of the present invention, the overflow of the gypsum cyclone first passes through the first mud hopper of the rapid sedimentation box, and then passes through the second mud hopper of the rapid sedimentation box. The bottom discharge outlets of the gypsum cyclone, the first mud hopper and the second mud hopper are respectively connected to the discharge pipeline, and the outlet of each discharge pipeline is arranged in sequence along the rotation direction of the upper belt of the vacuum belt dehydrator, and the discharge is output to the upper belt of the vacuum belt dehydrator.

[0010] As a further improvement of the present invention, the bottom discharge port of the gypsum cyclone continuously outputs large-particle gypsum, and the large-particle gypsum is spread evenly on the upper belt of the vacuum belt dehydrator.

[0011] As a further improvement of the present invention, the gypsum particle size output from the bottom discharge port of the first mud hopper is smaller than the gypsum particle size output from the bottom discharge port of the gypsum cyclone and larger than the gypsum particle size output from the bottom discharge port of the second mud hopper.

[0012] As a further improvement of the present invention, the first mud hopper continuously outputs gypsum to the upper belt of the vacuum belt dehydrator, and spreads gypsum with a particle size smaller than that of the gypsum at the bottom discharge outlet of the gypsum cyclone to the upper side of the gypsum output from the bottom discharge outlet of the gypsum cyclone.

[0013] As a further improvement of the present invention, the second mud hopper continuously outputs gypsum to the upper belt of the vacuum belt dehydrator, and spreads gypsum with a particle size smaller than that of the gypsum at the bottom discharge outlet of the first mud hopper to the upper side of the gypsum output from the bottom discharge outlet of the first mud hopper.

[0014] As a further improvement of the present invention, the intermediate water tank is arranged at a height lower than that of the rapid sedimentation tank, and the overflow port of the rapid sedimentation tank is connected to the water inlet of the intermediate water tank.

[0015] As a further improvement of the present invention, the wastewater cyclone is set at a height higher than the rapid sedimentation tank, one end of the water tank delivery pump is connected to the lower water outlet of the intermediate water tank, and the other end is connected to the water inlet of the wastewater cyclone.

[0016] As a further improvement of the present invention, the overflow port of the wastewater cyclone is connected to a wastewater treatment unit.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] The utility model uses a gypsum cyclone machine and a rapid sedimentation box to distinguish the particle sizes of gypsum in desulfurization wastewater, and spreads the gypsum with large particles at the bottom and small particles at the top on the vacuum belt dehydrator, so that the vacuum pump connected to the vacuum belt dehydrator dehydrates the gypsum on the upper side of the vacuum belt dehydrator, allowing air to pass through the gypsum from top to bottom and take away moisture. Since the gaps in the gypsum on the lower side are larger, air is easier to extract and is not easily blocked. The vacuum suction force can be efficiently and fully utilized to improve the dehydration efficiency, reduce the vacuum degree and the air extraction volume, and achieve low-cost operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a schematic diagram of a gypsum dehydration system disclosed in an embodiment of the present invention.

[0020] Description of reference numerals:

[0021] 1. Gypsum cyclone; 2. Rapid sedimentation tank; 3. Vacuum belt dehydrator; 4. Vacuum pump; 5. Intermediate water tank; 6. Water tank transfer pump; 7. Wastewater cyclone. DETAILED DESCRIPTION

[0022] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features therein can be combined with each other.

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" 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 device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0024] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "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 communication 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.

[0025] The present invention is described in further detail below with reference to the accompanying drawings:

[0026] like Figure 1As shown, the utility model provides a gypsum dehydration system, comprising: a gypsum cyclone 1, a rapid sedimentation box 2 and an intermediate water tank 5 connected in sequence via an overflow port, that is, the overflow port of the gypsum cyclone 1 is connected to the water inlet of the rapid sedimentation box 2, and the overflow port of the rapid sedimentation box 2 is connected to the water inlet of the intermediate water tank 5. A vacuum belt dehydrator 3 is provided below the gypsum cyclone 1 and the rapid sedimentation box 2. The vacuum belt dehydrator 3 is a conventional device in this field. A water pump is usually provided on the lower side of the upper belt to vacuum dehydrate the gypsum on the upper side of the upper belt. A sand settling nozzle is provided in the gypsum cyclone 1 to screen the particle size and precipitate the gypsum of a certain particle size. The rapid sedimentation box 2 adopts a horizontal flow sedimentation mode and is provided with multiple mud hoppers. , preferably two are set, including a first mud hopper and a second mud hopper, the gypsum cyclone 1 and the bottom discharge outlet of each mud hopper are connected to the upper belt of the vacuum belt dehydrator 3, and are arranged in sequence along the rotation direction of the upper belt of the vacuum belt dehydrator 3, the water pumping row on the lower side of the vacuum belt dehydrator 3 is connected to the vacuum pump 4, and the gypsum is dehydrated under the action of the vacuum pump 4; the intermediate water tank 5 is connected to the wastewater cyclone 7 through the water tank delivery pump 6, and the bottom discharge outlet of the wastewater cyclone 7 is connected to the rapid sedimentation tank 2, and the rapid sedimentation tank 2 removes the gypsum from the low flow in the wastewater cyclone 7 again, and repeatedly precipitates and recovers it through the wastewater cyclone 7 to ensure that more gypsum is obtained, so that the gypsum content in the desulfurization wastewater obtained by the overflow of the wastewater cyclone 7 is less than 3%;

[0027] The desulfurized slurry discharged from the desulfurization tower is connected to the gypsum cyclone 1. After the sand settling mouth, the gypsum with a particle size greater than 50 microns enters the bottom flow, and the gypsum with a particle size greater than 50 microns is precipitated and discharged from the bottom outlet of the gypsum cyclone 1 to the vacuum belt dehydrator 3. The gypsum with a particle size less than or equal to 50 microns overflows from the overflow port at the top of the gypsum cyclone 1 into the rapid sedimentation box 2. The gypsum in the overflow is sequentially precipitated by each mud hopper according to the particle size from large to small. If a first mud hopper and a second mud hopper are set, the gypsum with a particle size greater than 30 microns and less than or equal to 50 microns in the overflow enters the first mud hopper, and the gypsum with a particle size greater than 10 microns and less than or equal to 30 microns enters the first mud hopper. The gypsum of 10 microns enters the second mud hopper, and then the gypsum in the first mud hopper and the second mud hopper is discharged to the vacuum belt dehydrator 3. As the vacuum belt dehydrator 3 rotates, the gypsum with small particles covers the gypsum with large particles. The vacuum pump 4 dehydrates the gypsum on the upper belt of the vacuum belt dehydrator 3. The dehydrated gypsum leaves the vacuum belt dehydrator 3 at the end of the rotation direction of the upper belt of the vacuum belt dehydrator 3; at the same time, the gypsum with a particle size of less than 10 microns enters the intermediate water tank 5, and the gypsum is further removed under the action of the wastewater cyclone 7 to obtain desulfurized wastewater, which is then transported to the wastewater treatment unit for treatment.

[0028] In the present invention, the overflow of the gypsum cyclone 1 first passes through the first mud hopper of the rapid sedimentation box 2, and then passes through the second mud hopper of the rapid sedimentation box 2. The bottom discharge outlets of the gypsum cyclone 1, the first mud hopper and the second mud hopper are respectively connected to the discharge pipeline, and the outlets of each discharge pipeline are sequentially arranged along the rotation direction of the upper belt of the vacuum belt dehydrator 3, such as Figure 1 As shown, the vacuum belt dehydrator 3 rotates clockwise, and the bottom discharge outlet of the gypsum cyclone 1, the first hopper of the rapid sedimentation box 2, and the bottom discharge outlet of the second hopper are arranged from left to right along the upper side of the vacuum belt dehydrator 3, and the gypsum is output to the upper belt of the vacuum belt dehydrator 3 in sequence.

[0029] The bottom outlet of the gypsum cyclone 1 continuously outputs large-particle gypsum, which is spread evenly on the upper belt of the vacuum belt dehydrator 3. As the vacuum belt dehydrator 3 rotates, the belt already spread with large-particle gypsum rotates to the outlet of the first hopper discharge pipeline and the outlet of the second hopper discharge pipeline in sequence. The first mud hopper continuously outputs gypsum to the upper belt of the vacuum belt dehydrator 3, and spreads gypsum with a particle size smaller than that of the gypsum discharged from the bottom outlet of the gypsum cyclone 1 onto the upper side of the gypsum discharged from the bottom outlet of the gypsum cyclone 1; the second mud hopper continuously outputs gypsum to the upper belt of the vacuum belt dehydrator 3, and spreads gypsum with a particle size smaller than that of the gypsum discharged from the bottom outlet of the first mud hopper onto the upper side of the gypsum discharged from the bottom outlet of the first mud hopper.

[0030] The particle size of the gypsum output from the bottom outlet of the first mud hopper is smaller than the particle size of the gypsum output from the bottom outlet of the gypsum cyclone 1, and larger than the particle size of the gypsum output from the bottom outlet of the second mud hopper, thereby achieving the distribution of the gypsum on the upper side of the vacuum belt dehydrator 3 according to the particle size with larger particles at the bottom and smaller particles at the top. When the vacuum pump 4 is working, compared with traditional gypsum dehydration, after particle size separation, the gap at the bottom of the gypsum is enlarged and not easily clogged. The vacuum suction can be efficiently and fully utilized for rapid dehydration, thereby improving the dehydration efficiency, reducing the vacuum degree and the air extraction volume, and achieving low-cost operation.

[0031] In the present invention, the intermediate water tank 5 is set at a lower height than the rapid sedimentation tank 2, so that the overflow port of the rapid sedimentation tank 2 can be connected to the water inlet of the intermediate water tank 5, and the intermediate water tank 5 collects the sedimentation wastewater of the rapid sedimentation tank 2.

[0032] In the utility model, the setting height of the wastewater cyclone 7 is higher than the rapid sedimentation tank 2, so that the discharge from the bottom discharge port of the wastewater cyclone 7 automatically enters the rapid sedimentation tank 2. One end of the water tank delivery pump 6 is connected to the lower end water outlet of the intermediate water tank 5, and the other end is connected to the water inlet of the wastewater cyclone 7; the overflow port of the wastewater cyclone 7 is connected to the wastewater treatment unit.

[0033] In the present invention, the sand settling nozzle inside the gypsum cyclone 1 is made of ceramic; the first and second mud hoppers in the rapid sedimentation box 2 are both made of polytetrafluoroethylene; the operating negative pressure range of the vacuum belt dehydrator 3 is between 0.05 and 0.10 MPa, and the filter cloth is made of polyester PET; the intermediate water tank 5 is made of carbon steel lined with rubber and equipped with an agitator to prevent the formation of sediment, so that the water tank delivery pump 6 can smoothly deliver the precipitated wastewater in the intermediate water tank 5 to the wastewater cyclone 7; the water tank delivery pump 6 is a centrifugal pump, and the impeller is made of A49 steel; the overflow of the wastewater cyclone 7 obtains dehydrated wastewater, and the gypsum content in the desulfurization wastewater is less than 3%.

[0034] Example:

[0035] like Figure 1 As shown, the application process of the utility model gypsum dehydration system is as follows:

[0036] Step 1: Start the gypsum cyclone 1, the wastewater cyclone 7, the vacuum belt dehydrator 3, the vacuum pump 4, the water tank delivery pump 6, the vacuum pump 4 and the agitator in the intermediate water tank 5;

[0037] Step 2: continuously conveying the desulfurized slurry to the gypsum cyclone 1;

[0038] Step 3: The desulfurized slurry passes through the gypsum cyclone 1 and the internal sand settling nozzle, so that the gypsum with a particle size larger than 50 microns enters the underflow and is discharged from the bottom discharge port and spread flatly onto the upper belt of the vacuum belt dehydrator 3;

[0039] Step 4: Gypsum with a particle size of 50 microns or less in the desulfurized slurry flows from the overflow port of the gypsum cyclone 1 into the rapid sedimentation tank 2. The rapid sedimentation tank 2 is subjected to horizontal sedimentation. Gypsum with a particle size of greater than 30 microns and less than or equal to 50 microns is first precipitated in the first mud hopper and discharged from the bottom outlet of the first mud hopper and spread flatly on the upper side of the gypsum with a particle size greater than 50 microns on the vacuum belt dehydrator 3.

[0040] Step 5: The desulfurized slurry flows horizontally to the upper part of the second mud hopper, and gypsum with a particle size greater than 10 microns and less than or equal to 30 microns is precipitated in the second mud hopper, and discharged from the discharge port at the bottom of the second mud hopper and spread flat on the upper side of the gypsum with a particle size greater than 30 microns and less than or equal to 50 microns on the vacuum belt dehydrator 3;

[0041] Step 6: During the whole process, the vacuum belt dehydrator 3 keeps rotating and removes moisture from the gypsum through the vacuum pump 4. The gypsum after dehydration is separated from the right side of the vacuum belt dehydrator 3.

[0042] Step 7: The sedimentation wastewater overflowing from the overflow port of the rapid sedimentation tank 2 enters the intermediate water tank 5, which contains gypsum with a particle size of less than or equal to 10 microns. The water tank delivery pump 6 transports the sedimentation wastewater to the wastewater cyclone 7 for further treatment. The bottom flow is again input into the rapid sedimentation tank 2 for circulation treatment. The overflow obtains desulfurization wastewater and is transported to the wastewater treatment unit for treatment.

[0043] Advantages of this utility model:

[0044] The utility model uses a gypsum cyclone machine and a rapid sedimentation box to distinguish the particle sizes of gypsum in desulfurization wastewater, and spreads the gypsum with large particles at the bottom and small particles at the top on the vacuum belt dehydrator, so that the vacuum pump connected to the vacuum belt dehydrator dehydrates the gypsum on the upper side of the vacuum belt dehydrator, allowing air to pass through the gypsum from top to bottom and take away moisture. Since the gaps in the gypsum on the lower side are larger, air is easier to extract and is not easily blocked. The vacuum suction force can be efficiently and fully utilized to improve the dehydration efficiency, reduce the vacuum degree and the air extraction volume, and achieve low-cost operation.

[0045] The above are only preferred embodiments of the present invention and do not limit the present invention. For those skilled in the art, various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A gypsum dehydration system, characterized in that: include: A gypsum cyclone, a rapid sedimentation tank and an intermediate water tank are sequentially connected via an overflow port, a vacuum belt dehydrator is provided below the gypsum cyclone and the rapid sedimentation tank, a sand settling nozzle is provided in the gypsum cyclone, a plurality of mud buckets are provided in the rapid sedimentation tank, the bottom discharge ports of the gypsum cyclone and each mud bucket are connected to the upper belt of the vacuum belt dehydrator, and are sequentially arranged along the rotation direction of the upper belt of the vacuum belt dehydrator, and the vacuum belt dehydrator is connected to a vacuum pump; the intermediate water tank is connected to the wastewater cyclone via a water tank delivery pump, and the bottom discharge port of the wastewater cyclone is connected to the rapid sedimentation tank; The desulfurization slurry discharged from the desulfurization tower is connected to the gypsum cyclone, and large-particle gypsum is precipitated through the sand settling nozzle and discharged to the vacuum belt dehydrator from the bottom outlet. The overflow enters the rapid sedimentation box, and the gypsum in the overflow is precipitated by each mud bucket in order from large to small according to the particle size, and discharged to the vacuum belt dehydrator. As the vacuum belt dehydrator rotates, the small-particle gypsum covers the large-particle gypsum, and the vacuum pump dehydrates the gypsum on the upper belt of the vacuum belt dehydrator. The dehydrated gypsum leaves the vacuum belt dehydrator at the end of the rotation direction of the upper belt of the vacuum belt dehydrator.

2. The gypsum dehydration system according to claim 1, characterized in that: The rapid sedimentation box adopts an advection sedimentation mode and is provided with a first mud hopper and a second mud hopper.

3. The gypsum dehydration system according to claim 2, characterized in that: The overflow of the gypsum cyclone first passes through the first mud hopper of the rapid sedimentation box, and then passes through the second mud hopper of the rapid sedimentation box. The bottom discharge outlets of the gypsum cyclone, the first mud hopper and the second mud hopper are respectively connected to the discharge pipeline, and the outlet of each discharge pipeline is arranged in sequence along the rotation direction of the upper belt of the vacuum belt dehydrator, and the discharge is output to the upper belt of the vacuum belt dehydrator.

4. The gypsum dehydration system according to claim 1, characterized in that: The bottom discharge port of the gypsum cyclone continuously outputs large-diameter gypsum, and the large-diameter gypsum is spread flat on the upper belt of the vacuum belt dehydrator.

5. The gypsum dehydration system according to claim 2, characterized in that: The particle size of gypsum outputted from the bottom discharge port of the first mud hopper is smaller than the particle size of gypsum outputted from the bottom discharge port of the gypsum cyclone, and larger than the particle size of gypsum outputted from the bottom discharge port of the second mud hopper.

6. The gypsum dehydration system according to claim 5, characterized in that: The first mud bucket continuously outputs gypsum to the upper belt of the vacuum belt dehydrator, and spreads gypsum with a particle size smaller than that of the gypsum at the bottom discharge outlet of the gypsum cyclone to the upper side of the gypsum output from the bottom discharge outlet of the gypsum cyclone.

7. The gypsum dehydration system according to claim 6, characterized in that: The second mud hopper continuously outputs gypsum to the upper belt of the vacuum belt dehydrator, and spreads gypsum with a smaller particle size than that of the gypsum at the bottom discharge outlet of the first mud hopper to the upper side of the gypsum output from the bottom discharge outlet of the first mud hopper.

8. The gypsum dehydration system according to claim 1, characterized in that: The intermediate water tank is arranged at a height lower than that of the rapid sedimentation tank, and the overflow port of the rapid sedimentation tank is connected to the water inlet of the intermediate water tank.

9. The gypsum dehydration system according to claim 1, characterized in that: The wastewater cyclone is arranged at a height higher than the rapid sedimentation tank. One end of the water tank delivery pump is connected to the lower water outlet of the intermediate water tank, and the other end is connected to the water inlet of the wastewater cyclone.

10. The gypsum dehydration system according to claim 1, characterized in that: The overflow port of the wastewater cyclone is connected to a wastewater treatment unit.

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