Method for reducing moisture of flotation clean coal

Abstract

The invention discloses a method for reducing the moisture of flotation clean coal, which comprises the following steps of: 1, transforming a screen sedimentation centrifuge to reduce the product moisture of the screen sedimentation centrifuge; and 2, replacing the filter press to reduce the product moisture of the filter press. According to the invention, under the condition that the coal quality does not have special change, the coal moisture of the final product is reduced from 13%-14% to 12% or below, and the specified standard is reached.

Description

Technical Field

[0001] The invention relates to a method for reducing the moisture content of flotation clean coal, belonging to the technical field of coal processing. Background Art

[0002] The flotation clean coal dehydration of a certain company's coal preparation plant uses a screen sedimentation centrifuge in combination with two quick-opening filter presses for dehydration. The screen sedimentation centrifuge has a large single-machine processing capacity, and the equipment operates continuously without interruption, which can effectively make up for the defects of intermittent operation of the filter press. At the same time, the equipment has a high degree of automation and low labor costs. The quick-opening filter press can recover solid particles as much as possible, and the solid-liquid separation effect is good. The two equipment are used together to give full play to their respective advantages. However, due to the small size of the equipment selection in the early stage, the backward technical indicators, the insufficient capacity of the flotation clean coal dehydration equipment, the poor dehydration effect of the screen sedimentation centrifuge, the product moisture content of 20%~25%, and the assessment standard of the product moisture content does not meet the production requirements; the original quick-opening filter press has been used for a long time, the equipment failure rate is high, and the original quick-opening is a low-pressure quick-opening with a pressing pressure of 0.6Mpa. When the flotation clean coal is dehydrated, the moisture content is about 24%~26%, and the flotation clean coal moisture content remains high, resulting in a high moisture content in the final clean coal product. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for reducing the moisture content of flotation clean coal, so as to solve the technical problems existing in the above-mentioned prior art.

[0004] The technical solution adopted by the present invention is: a method for reducing the moisture content of flotation clean coal, comprising the following steps: Step 1: Reconstruct the screen sedimentation centrifuge to reduce the product moisture of the screen sedimentation centrifuge; Step 2: Replace the filter press to reduce the moisture content of the filter press product.

[0005] Preferably, the step 1 includes setting the holes on the periphery of the screen segment of the screen sedimentation centrifuge as strip-shaped inclined holes, and the angle of the strip-shaped inclined holes is consistent with the rise angle of the spiral blades inside the drum of the screen sedimentation centrifuge.

[0006] Preferably, the strip-shaped oblique holes on the outer circumference of the screen segment of the screen sedimentation centrifuge are cut by laser.

[0007] Preferably, the step one further comprises setting the transmission device of the screen sedimentation centrifuge as a permanent magnetic coupler.

[0008] Preferably, the step 1 further comprises setting the weir plate of the drum of the screen sedimentation centrifuge to block the lower end of the overflow port of the drum of the screen sedimentation centrifuge by 0-3 cm.

[0009] Preferably, in step 2, a high-pressure diaphragm filter press is used to replace the original quick-opening filter press.

[0010] Preferably, the model of the high-pressure diaphragm filter press is HMAZG518M2 / 2000-U, and the pressing pressure is 2.0 MPa.

[0011] Beneficial effects of the present invention: Compared with the prior art, in the present invention, under the condition that the coal quality does not change significantly, the moisture content of the final product coal is reduced from 13% to 14% to below 12%, reaching the specified standard. After the moisture content is reduced, the loss caused during storage and transportation and the phenomenon of loss of tons reflected by the large difference in the number of goods received by customers can be reduced, saving transportation costs. Based on the production of 40,000 tons of clean coal per month, a 2% reduction in moisture content can save the transportation cost of 800 tons of coal. Based on the average freight rate of 150 yuan / ton, the monthly transportation cost can be saved by 120,000 yuan. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the drum structure of an existing screen sedimentation centrifuge.

[0013] Figure 2 It is a schematic diagram of the drum structure of the screen sedimentation centrifuge in the present invention.

[0014] The reference numerals in the drawings of the specification include: solid discharge port 1, screen segment 2, cone segment 3, cylindrical segment 4, weir plate 5, overflow port 6. DETAILED DESCRIPTION

[0015] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0016] Embodiment 1: The method for reducing the moisture content of flotation clean coal comprises the following steps: Step 1: Reconstruct the screen sedimentation centrifuge to reduce the product moisture of the screen sedimentation centrifuge; Step 2: Replace the filter press to reduce the moisture content of the filter press product.

[0017] In step 1, the screen sedimentation centrifuge includes a drum, such as Figure 2 As shown, the drum includes a solid discharge port 1, a screen segment 2, a conical segment 3, a cylindrical segment 4, and an overflow port 6 which are connected in sequence. A weir plate 5 is provided inside the drum at one end close to the overflow port 6. The screen segment 2 is in a circular tube shape. The holes on the outer circumference of the screen segment 2 are strip-shaped inclined holes. The angle of the strip-shaped inclined holes is consistent with the rise angle of the spiral blades inside the drum. The strip-shaped inclined holes on the outer circumference of the screen segment 2 are formed by laser cutting.

[0018] like Figure 1As shown, the holes on the periphery of the screen segment 2 of the existing screen sedimentation centrifuge are circular holes, which are inconsistent with the direction of material movement. The material needs to be dehydrated repeatedly for many times. The holes on the periphery of the screen segment 2 in this embodiment are strip-shaped inclined holes. The angle of the strip-shaped inclined holes is consistent with the rise angle of the spiral blades inside the drum. The direction of material movement is consistent with the direction of the strip-shaped inclined holes, which can improve the dehydration efficiency and effectively reduce the moisture content of the product.

[0019] In this embodiment, Figure 2 As shown, the weir plate 5 blocks the lower end of the overflow port 6 by 1 cm, and as Figure 1 As shown, the weir plate 5 in the prior art blocks the lower end of the overflow port 6 by 5 cm. In this embodiment, the overflowing centrifuge liquid is discharged as quickly as possible by lowering the height of the overflow weir plate 5, thereby effectively reducing the moisture content of the product.

[0020] In this embodiment, the transmission device of the screen sedimentation centrifuge is a permanent magnetic coupler, while the TVYC562 hydraulic coupler is used in the prior art. The hydraulic coupler mainly uses the liquid in the coupler as the medium for energy transfer, and a large amount of heat will be generated during use. The heat is concentrated inside the coupler, and the heat dissipation effect is not very good. The greater the load, the greater the heat generated, and the higher the medium temperature, which eventually leads to the explosion of the fusible plug of the coupler; and the permanent magnetic coupler structure is divided into two parts, one part is two steel basins fixed on the input shaft, and the other part is two permanent magnetic disks fixed on the load side, and there is a gap of 3 to 7 mm between the steel basin and the disk. Energy is transferred through the attraction of the magnetic disk to the steel basin. Since there is no direct contact between the magnetic disk and the steel basin, the heat during use mainly comes from the heat generated by the friction between the coupler and the air. The coupler temperature is generally within 40°C. The permanent magnet coupler uses non-contact electromagnetic coupling transmission, which can be started flexibly and can achieve performance close to direct connection after starting. The transmission efficiency of the original hydraulic coupler is increased from 0.95 to 0.98, and the drum speed is increased from 880r / min to 906r / min, which increases the centrifugal force, reduces the moisture content of the product, and can also reduce the production impact caused by frequent over-temperature fusible plug leakage of the hydraulic coupler.

[0021] After the present embodiment was put into actual production and use in a certain mine, the moisture content of the product of the screen sedimentation centrifuge was significantly reduced and stabilized at 16% to 18%.

[0022] The permanent magnet coupler has a simple structure, is easy to install, and is intuitive to inspect. Once debugged, it requires almost no subsequent capital investment and does not require a lot of maintenance. It only requires regular inspection of the fixing bolts and dust removal of the equipment. This can reduce the coupler maintenance costs by 110,000 yuan each year and also reduces a lot of labor investment.

[0023] In step 2, the original KMZG500 / 2000-U filter press is replaced with a HMAZG518M2 / 2000-U high-pressure diaphragm filter press, the pressing pressure is increased to 2.0MPa, the air flow function is increased, and the moisture content of the flotation clean coal processed in the same time can be reduced to below 20%.

[0024] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for reducing the moisture content of flotation clean coal, characterized in that: The following steps are involved: Step 1: Reconstruct the screen sedimentation centrifuge to reduce the product moisture of the screen sedimentation centrifuge; Step 2: Replace the filter press to reduce the moisture content of the filter press product.

2. The method for reducing the moisture content of flotation clean coal according to claim 1, characterized in that: The step 1 includes setting the holes on the outer periphery of the screen segment of the screen sedimentation centrifuge as strip-shaped inclined holes, wherein the angle of the strip-shaped inclined holes is consistent with the rise angle of the spiral blades inside the drum of the screen sedimentation centrifuge.

3. The method for reducing the moisture content of flotation clean coal according to claim 2, characterized in that: The strip-shaped oblique holes on the outer circumference of the screen segment of the screen sedimentation centrifuge are cut by laser.

4. The method for reducing the moisture content of flotation clean coal according to claim 1, characterized in that: The step 1 also includes setting the transmission device of the screen sedimentation centrifuge as a permanent magnetic coupler.

5. The method for reducing the moisture content of flotation clean coal according to claim 1, characterized in that: The step 1 also includes setting the weir plate of the drum of the screen sedimentation centrifuge to block the lower end of the overflow port of the drum of the screen sedimentation centrifuge by 0-3 cm.

6. The method for reducing the moisture content of flotation clean coal according to claim 1, characterized in that: In the step 2, the original quick-opening filter press is replaced by a high-pressure diaphragm filter press.

7. The method for reducing the moisture content of flotation clean coal according to claim 6, characterized in that: The model of the high-pressure diaphragm filter press is HMAZG518M2 / 2000-U, and the pressing pressure is 2.0MPa.

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