Centrifugal machine dehydration system and dehydration method

Abstract

The centrifugal machine dehydration system comprises two stages of centrifugal machines, the centrifugal machines are screen sedimentation centrifugal machines, and the two stages of centrifugal machines comprise the first-stage screen sedimentation centrifugal machine and the second-stage screen sedimentation centrifugal machine which are directly connected in series; raw coal slurry enters a first-stage screen sedimentation centrifuge, and first-stage centrifugal coal, first-stage filtrate and first-stage centrifugate are produced after low-speed long-time dehydration; the first-stage centrifugate returns to the first-stage screen sedimentation centrifuge again; the first-stage filtrate is directly pumped into a second-stage screen sedimentation centrifuge, superfine particles are separated through high centrifugal force, second-stage centrifugal coal, second-stage filtrate and second-stage centrifugate are produced, and the second-stage centrifugate is returned to the second-stage screen sedimentation centrifuge again; the second-stage filtrate is reused as coal washing circulating water, and the first-stage centrifugal coal and the second-stage centrifugal coal are mixed and then are sold as a single product. Through the two-stage centrifugal mechanism, the dehydration efficiency is improved, the energy consumption is reduced, and the production benefit is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of coal slurry separation, and particularly relates to a centrifuge dehydration system and a dehydration method. Background Art

[0002] In the field of coal washing, fine coal dehydration is a critical step affecting product quality and economic benefits. Traditional processes use a screen-sedimentation centrifuge to initially dehydrate the coal slurry, producing centrifuged coal and a filtrate containing fine particles. Because the filtrate still contains a large amount of ultrafine coal slime, it must be further processed through a thickening tank, where chemicals are added to settle the filtrate, before being pressed into a cake-like filter press.

[0003] Existing technologies primarily aim to improve dewatering efficiency by optimizing filter press performance (such as high-pressure membrane filter presses) or by modifying the dosage of reagents in the concentration tank. Additionally, some approaches attempt to connect a centrifuge and filter press directly in series, but this still requires pre-concentration of the filtrate.

[0004] However, the existing fine coal dehydration process is complex and costly. The filtrate must be concentrated in a thickening tank before being pumped to a filter press, increasing construction costs and operational complexity. Furthermore, the equipment's processing capacity is mismatched. The filter press has a low single-unit processing capacity and cannot be efficiently connected to the front-end screen sedimentation centrifuge, creating a production capacity bottleneck. The overall cost is too high. The filter press is expensive to purchase and complex to maintain, and requires a high-strength foundation and factory building, further increasing investment. The low level of intelligence makes it difficult to operate the filter press unmanned, relying on manual operation and limiting efficiency. The by-product value is low. Due to its high water content and cake-like structure, the filtered coal requires secondary crushing, resulting in a significantly lower selling price than centrifugally dehydrated coal. Equipment compatibility is poor, and the existing process requires multiple links (centrifuge + thickening tank + filter press), resulting in low system stability and a dispersed risk of failure. Summary of the Invention

[0005] Based on the technical problems existing in the prior art, the present invention provides a centrifuge dehydration system and method, which adopts a two-stage centrifuge system and achieves efficient separation through a two-stage screen structure, solving the problems of the prior art such as large footprint, high cost, and reliance on manual operation.

[0006] According to the first aspect of the technical solution of the present invention, the present invention provides a centrifuge dehydration system, which is composed of a two-stage centrifuge, the centrifuge is a screen sedimentation centrifuge, the two-stage centrifuge includes a first-stage screen sedimentation centrifuge and a second-stage screen sedimentation centrifuge, the first-stage screen sedimentation centrifuge and the second-stage screen sedimentation centrifuge are directly connected in series, without the need for an intermediate concentration link, and the clear liquid is directly reused or discharged.

[0007] Preferably, the first-stage screen decanter centrifuge adopts a low-speed, large-screen-slot design, and the speed of the first-stage screen decanter centrifuge is any speed between 550 rpm and 1000 rpm.

[0008] Preferably, the screen gap of the primary screen bowl centrifuge is set to any length within the range of 0.1mm-1mm.

[0009] Preferably, the secondary screen bowl centrifuge adopts a high speed and small screen gap design, and the rotational speed of the secondary screen bowl centrifuge is any rotational speed within the range of 750rpm-3000rpm.

[0010] Preferably, the screen gap of the secondary screen bowl centrifuge is set to less than 0.3mm.

[0011] According to the second aspect of the technical scheme of the present application, the present application provides a method for using a centrifuge dewatering system, which uses the above-mentioned centrifuge dewatering system, and comprises the following steps:

[0012] Step S1: the coal slurry to be dewatered enters the primary screen bowl centrifuge through a pipeline for dewatering, to obtain primary centrifuged coal, primary centrifuged liquid and primary filtrate; the primary filtrate is returned to the primary screen bowl centrifuge for re-dewatering;

[0013] Step S2: the primary centrifuged liquid in step S1 enters the secondary screen bowl centrifuge for dewatering, to obtain secondary centrifuged coal, secondary centrifuged liquid and secondary filtrate; the secondary filtrate is returned to the secondary screen bowl centrifuge for re-dewatering;

[0014] Step S3: the primary centrifuged coal in step S1 and the secondary centrifuged coal in step S4 are mixed for sale.

[0015] Preferably, the water content of the primary centrifuged coal is ≤22%, which is directly used as a final product.

[0016] Preferably, the primary centrifuged liquid discharged from the overflow weir hole at the rear end of the primary screen bowl centrifuge is transported to the secondary screen bowl centrifuge through a pipeline.

[0017] Preferably, the water content of the secondary centrifuged coal is ≤24%, which is directly used as a final product.

[0018] Preferably, the secondary centrifuged liquid discharged from the overflow weir hole at the rear end of the secondary screen bowl centrifuge is clear liquid, which is directly used as circulating water or flushing water.

[0019] Compared with the prior art, the present application has the following beneficial technical effects:

[0020] 1. The present application has a small footprint and reduces investment, and compared with the prior art, the footprint of the thickening tank and the filter press is reduced (usually 50m 2 -100m 2) and drug costs (drug costs account for 10%-15% of the total cost of the dehydration system) and the concentration efficiency in the prior art is limited by the drug reaction time. The two-stage centrifuge of the present invention can be stacked up and down or placed horizontally (occupying an area of ​​50m 2 -60m 2 ), saving 40%-50% of the plant space, and the foundation bearing requirement is only 60% of the traditional process, and two types of equipment are reduced, and the investment is reduced by 50%; there is no need for high-pressure pumps, filter cloths and other consumables related to the filter press, and the annual maintenance cost is greatly reduced.

[0021] 2. The present invention reduces coal slurry processing time and increases output. Existing filter presses typically have low processing capacity (typically 5-10 t / h), high energy consumption (high-pressure pump power 30-50 kW), and frequent filter cloth replacement (every three months). A single filter press cycle takes 1-2 hours. The present invention replaces filter presses with centrifuges, which provide continuous, uninterrupted processing and improve efficiency by 60%-80%. Each centrifuge weighs approximately 20-30 tons, while each filter press has a load capacity of approximately 60-70 tons. Centrifuges require minimal plant space.

[0022] 3. The present invention has high economic benefits. The centrifuge produces centrifugal coal, and the filter press produces filter press coal. The filter press coal needs to be broken up by a crusher before use. The selling price of the filter press coal is much lower than that of the centrifugal coal. At the same time, high-grade centrifugal coal is uniformly produced, avoiding the selling price loss caused by mixing the filter press coal.

[0023] 4. The present invention allows for interchangeable parts: most of the parts of the first-stage screen decanter centrifuge and the second-stage screen decanter centrifuge can be used interchangeably, thus reducing spare parts inventory and lowering spare parts costs.

[0024] 5. The present invention is intelligently upgraded and intelligently compatible, and the centrifuge is easy to integrate with automatic control, reducing the need for manual intervention; the centrifuge can achieve full automatic control through variable frequency speed regulation and online moisture content monitoring, greatly reducing the need for manual intervention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 1 is a schematic diagram of the steps of the centrifuge dehydration method according to the present invention. DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0027] It should also be noted that, for ease of description, only the parts related to the invention are shown in the drawings. In the absence of conflict, the embodiments and features of the embodiments of the present invention may be combined with each other.

[0028] It should be noted that the concepts of "first" and "second" mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0029] It should be noted that the modifications of "one" and "multiple" mentioned in the present invention are illustrative rather than restrictive. Those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0030] The present invention discloses a centrifuge dehydration system and method. The centrifuge dehydration system includes a two-stage centrifuge, wherein the centrifuge is a screen decanter centrifuge. The two-stage centrifuge includes a first-stage screen decanter centrifuge and a second-stage screen decanter centrifuge. The first-stage screen decanter centrifuge and the second-stage screen decanter centrifuge are directly connected in series. The raw coal slurry enters the first-stage screen decanter centrifuge and, after long-term low-speed dehydration, produces first-stage centrifuged coal, first-stage filtrate, and first-stage centrifuge liquid. The first-stage centrifuge liquid is then returned to the first-stage screen decanter centrifuge. The first-stage filtrate is directly pumped into the second-stage screen decanter centrifuge, where ultrafine particles are separated by high centrifugal force to produce second-stage centrifuged coal, second-stage filtrate, and second-stage centrifuge liquid. The second-stage centrifuge liquid is then returned to the second-stage screen decanter centrifuge. The second-stage filtrate is reused as coal washing circulating water, and the first-stage centrifuged coal and the second-stage centrifuged coal are mixed and sold as a single product. The two-stage centrifugal mechanism improves dehydration efficiency, reduces energy consumption, and improves production efficiency.

[0031] The centrifuge dehydration system of the present invention is described in detail below with reference to the accompanying drawings.

[0032] like Figure 1 As shown, compared with the traditional centrifugal dehydration process (centrifuge + concentrator + filter press), a centrifuge dehydration system reduces the concentrator and filter press, adopts a two-stage centrifuge system, and achieves efficient separation through a two-stage screen structure. The first-stage screen processes larger particles or high-concentration slurry, and the second-stage screen further separates fine particles, thereby improving separation accuracy and efficiency.

[0033] A centrifuge dehydration system includes a two-stage centrifuge, wherein the centrifuge is a screen decanter centrifuge, which further includes a first-stage screen decanter centrifuge and a second-stage screen decanter centrifuge. The first-stage screen decanter centrifuge and the second-stage screen decanter centrifuge are directly connected in series without the need for an intermediate concentration link, and the clear liquid is directly reused or discharged.

[0034] The first-stage decanter centrifuge features a low-speed, large-screen design. This low speed reduces material flow within the drum, prolonging the dehydration time and ensuring sufficient dehydration of coarse particles, prioritizing their removal and producing centrifuged coal with a low moisture content. In a preferred embodiment, the first-stage decanter centrifuge operates at a speed between 550 rpm and 1000 rpm. The large screen gaps allow for rapid drainage of moisture and ultrafine particles, preventing screen clogging while minimizing coarse particle loss. In a preferred embodiment, the screen gaps in the first-stage decanter centrifuge are set to a length between 0.1 mm and 1 mm.

[0035] The secondary screen centrifuge utilizes a high-speed, small-gap design. This high speed forces ultrafine particles to overcome fluid resistance and settle. In a preferred embodiment, the secondary screen centrifuge operates at speeds between 750 rpm and 3000 rpm. The small gap creates a filter membrane in the coal slurry, preventing particle discharge and allowing only water to pass through, ultimately producing fine-grained centrifuged coal with a satisfactory moisture content. In a preferred embodiment, the gap in the secondary screen centrifuge is set to less than 0.3 mm.

[0036] The present invention adopts parameter collaborative design, combining the low speed and large screen gap design of the first-stage screen decanter centrifuge with the high speed and small screen gap design of the second-stage screen decanter centrifuge to achieve full-size classification dehydration; at the same time, a direct series process is adopted, and the filtrate directly enters the second-stage screen decanter centrifuge without concentration, thereby simplifying the process.

[0037] The following describes how the present invention improves system processing efficiency and achieves equipment processing capacity matching with embodiments, and further describes the centrifuge dehydration system and dehydration method of the present invention in detail.

[0038] Example 1: Take centrifuge BSB1133 as an example.

[0039] 1. Basic parameters of centrifuge BSB1133. “BSB1133” is the serial number of the centrifuge produced by the applicant.

[0040] Processing capacity: The processing capacity of centrifuge BSB1133 is 40-60 tons / hour on a dry basis ("dry basis" refers to the solid content of the processed material, excluding water or other liquid components);

[0041] Separation efficiency: solid recovery rate is 80%;

[0042] Liquid product: The solid content in the centrifuge liquid is 8-12 tons / hour.

[0043] 2. Existing technical solution (centrifuge + concentrator + filter press)

[0044] Based on the principle of matching the filter press's processing capacity with the solids content of the centrifuge, a 1:1 matching relationship is required. That is, each BSB1133 centrifuge requires a filter press with a processing capacity of 8-12 t / h to achieve a balanced production capacity for the solid-liquid separation system. The "BSB1133" in the BSB1133 centrifuge is the serial number of the centrifuge produced by the applicant.

[0045] 3. The two-stage centrifuge supporting scheme of the present invention

[0046] Option 1: One BSB1133 first-stage screen decanter centrifuge and one BSB0918 second-stage screen decanter centrifuge.

[0047] Option 2: 5 BSB1133 first-stage screen decanter centrifuges + 1 BSB1133 second-stage screen decanter centrifuge.

[0048] If the first option is adopted, it can be expressed as output equilibrium;

[0049] If the second option is adopted, it can be expressed as an increase in production capacity, using fewer devices to complete the work of more devices; that is, the overall production capacity of the system is improved while ensuring separation efficiency.

[0050] 4. Process parameter optimization

[0051] Load distribution: The first-stage screen sedimentation centrifuge undertakes about 80% of the dehydration task and completes the dehydration of coarse particles; the second stage processes the remaining 20% ​​of fine particles to avoid equipment overload.

[0052] Advantages of classification treatment: achieve coal slurry particle size classification treatment, extend equipment service life and optimize energy utilization efficiency.

[0053] The centrifuge dewatering system includes two stages, both of which produce centrifuged coal in a completely bulk form. This is because the coal slurry travels along the centrifuge's spiral and evenly spreads across the entire inner wall of the rotor, dewatering as it travels. Once it reaches the discharge port, centrifugal force and a discharge scraper evenly discharge the centrifuge. The centrifuged coal produced by the centrifuge does not clump, but rather appears as a completely bulk material, consisting of particles smaller than 3 mm. Conventional filter presses, on the other hand, dehydrate the coal by squeezing water out of the filter plates under pressure. This results in the dehydrated coal forming lumps or cakes, as the filter press compresses the coal into a single piece. This type of coal cannot be directly used in applications such as power generation or the chemical industry; instead, the filter press coal lumps must be fed into a crusher for secondary crushing to break them into bulk form. Therefore, the centrifuged coal produced using the present invention commands a higher price than filter press coal, improving the quality of the dehydrated coal and preventing the production of low-value filter press coal.

[0054] In order to better achieve the above-mentioned object of the invention, the present invention also provides a centrifuge dehydration method, comprising the following steps:

[0055] Step S1: The coal slurry to be dehydrated enters a first-stage screen sedimentation centrifuge through a pipeline for dehydration; the coal slurry to be dehydrated with a particle size distribution of 0mm-3mm and a solid content of generally 20%-55% is sent to the first-stage screen sedimentation centrifuge through a pipeline. In a preferred embodiment, a buffer tank is set between the pipeline and the first-stage screen sedimentation centrifuge to adjust the flow and pressure of the coal slurry to ensure stable operation of the centrifuge. The rotation speed of the first-stage screen sedimentation centrifuge is set to a low rotation speed. In a preferred embodiment, the low rotation speed is any rotation speed between 550rpm and 1000rpm. The residence time of the coal slurry is extended by the low rotation speed to achieve preliminary dehydration of coarse particles (>0.05mm). The screen gap of the first-stage screen sedimentation centrifuge is set to any length between 0.1mm and 1mm. The large screen gap setting of the first-stage screen sedimentation centrifuge allows moisture and ultrafine particles (<0.0451mm) to be quickly discharged, forming a first-stage centrifugal coal with a low moisture content (≤22%). The products of the preliminary dehydration of the first-stage screen sedimentation centrifuge are first-stage centrifugal coal, first-stage centrifugal liquid and first-stage filtrate. In a preferred embodiment, the moisture content of the first-stage centrifuged coal is ≤22% and can be directly used as the final product; the first-stage filtrate is directly returned to the first-stage screen sedimentation centrifuge for further dehydration; the first-stage centrifuge liquid discharged from the overflow weir hole at the rear end of the first-stage screen sedimentation centrifuge is transported to the second-stage screen sedimentation centrifuge through a pipeline, and the solid content of the first-stage centrifuge liquid is 5%-10%. In a preferred embodiment, the first-stage screen sedimentation centrifuge operates stably and continuously, and the first-stage centrifuge liquid is stably output.

[0056] Step S2: The primary centrifuge from Step S1 enters a secondary mesh decanter centrifuge for dehydration. The primary centrifuge, with a solids content of 5%-10%, is piped to the secondary mesh decanter centrifuge. The secondary mesh decanter centrifuge is set to a high speed. In a preferred embodiment, the low speed is between 750 rpm and 3000 rpm. The high speed provides strong centrifugal force, forcing ultrafine particles to settle. The small slits in the secondary mesh decanter centrifuge screen only allow water to pass through, trapping ultrafine particles and forming fine centrifuged coal. The products of deep dehydration in the secondary mesh decanter centrifuge are secondary centrifuged coal, secondary centrifuge, and secondary filtrate. In a preferred embodiment, the moisture content of the secondary centrifuged coal is ≤24% and can be used directly as the final product. The secondary filtrate is directly returned to the secondary mesh decanter centrifuge for further dehydration. The secondary centrifuge, discharged from the overflow weir at the rear end of the secondary mesh decanter centrifuge, is clarified liquid and can be directly used as circulating water or flushing water.

[0057] Step S3: The first-stage centrifugal coal in step S1 and the second-stage centrifugal coal in step S2 are mixed and sold.

[0058] The centrifuge dehydration method of the present invention eliminates the need for external concentration or filter press intervention. The two-stage centrifuge forms a closed-loop system, and the secondary centrifuge fluid is recycled as clarified liquid, reducing water consumption and meeting green production requirements. The two-stage centrifuge can be stacked or positioned horizontally, saving factory space, and the foundation load requirement is only 60% of that of traditional processes.

[0059] A centrifuge dehydration method is described in detail below with reference to embodiments.

[0060] Example 2: Taking centrifuge BSB1133 as an example, further comprising the following steps:

[0061] Step A1: The coal slurry to be dehydrated (particle size 0mm-3mm, solids content 20%-55%) is piped to a BSB1133 centrifuge. The BSB1133 centrifuge has a dry-base throughput of 40-60 t / h, a solids recovery rate of 80%, and a solids content of 8-12 t / h in the centrifuge. A buffer tank is installed between the pipeline and the BSB1133 centrifuge to regulate the flow and pressure of the coal slurry and ensure stable operation of the BSB1133 centrifuge. The BSB1133 centrifuge is set to a speed of 550-1000 rpm (low speed mode) and a screen size of 0.1mm-1mm. By extending the residence time of the coal slurry, it can achieve efficient dehydration of coarse particles (>0.05mm). The product of the initial dehydration of the BSB1133 centrifuge is first-stage centrifuged coal (moisture content ≤ 22%), which can be directly used as the finished product; the first-stage centrifuge liquid (solid content 5%-10%) is transported to the BSB0918 centrifuge through the overflow weir hole; the first-stage filtrate is returned to the BSB1133 centrifuge for recycling treatment.

[0062] Step A2: The primary centrifuge (solid content 5%-10%) is transported to the BSB0918 centrifuge through a pipeline. The speed of the BSB0918 centrifuge is set to 750rpm-3000rpm (high speed mode), the sieve size is reduced to <0.3mm, and the ultrafine particles (<0.045mm) are forced to settle by enhancing the centrifugal force; the product of deep dehydration in the BSB0918 centrifuge is secondary centrifuged coal (moisture content ≤24%), and the particle size distribution is concentrated in the fine particle size; the secondary centrifuge (clarified liquid, SS ≤0.5%) can be reused as circulating water; the secondary filtrate is returned to the BSB0918 centrifuge for circulation treatment.

[0063] Step A3: The first-stage centrifugal coal and the second-stage centrifugal coal are mixed according to process requirements to form a final product with a moisture content of ≤23%. The second-stage centrifugal liquid is purified and then incorporated into the plant's water circulation system, achieving a water resource reuse rate of ≥95%.

[0064] In summary, the present invention provides a centrifuge dehydration system and method. Through the synergistic effect of a two-stage screen sedimentation centrifuge, the present invention achieves the following improvements and obtains the following technical effects:

[0065] Process simplification: the concentration tank and filter press are eliminated, and the filtrate is directly processed by the second-stage screen sedimentation centrifuge;

[0066] Improved efficiency: Two-stage centrifuge parameter adaptation (speed, screen gap) enables efficient dehydration of all-size coal slimes;

[0067] Cost optimization: Reduce equipment investment and operating energy consumption while producing a single high-value centrifugal coal;

[0068] Intelligent upgrade: The centrifuge is easy to integrate with automatic control, reducing the need for manual intervention.

[0069] Interchangeable parts: Most of the parts of the first-stage screen decanter centrifuge and the second-stage screen decanter centrifuge are interchangeable, reducing spare parts inventory and spare parts costs;

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A centrifuge dehydration system comprising a two-stage centrifuge, characterized in that: The centrifuge is a screen decanter centrifuge. The two-stage centrifuge includes a first-stage screen decanter centrifuge and a second-stage screen decanter centrifuge. The first-stage screen decanter centrifuge and the second-stage screen decanter centrifuge are directly connected in series without the need for an intermediate concentration link, and the clear liquid is directly reused or discharged.

2. The centrifuge dehydration system according to claim 1, characterized in that: The first-stage screen decanter centrifuge adopts a low-speed and large-screen-slot design. The speed of the first-stage screen decanter centrifuge is any speed between 550rpm and 1000rpm.

3. The centrifuge dehydration system according to claim 2, characterized in that: The sieve gap of the first-stage sieve sedimentation centrifuge is set to any width between 0.1mm and 1mm.

4. The centrifuge dehydration system according to claim 1, characterized in that: The secondary screen centrifuge adopts a high speed and small screen gap design. The speed of the secondary screen sedimentation centrifuge is any speed between 750rpm-3000rpm.

5. The centrifuge dehydration system according to claim 4, characterized in that: The sieve gap of the secondary screen sedimentation centrifuge is set to be less than 0.3mm.

6. A centrifuge dehydration method, characterized in that: The centrifuge dehydration system according to any one of claims 1 to 5 is used, and comprises the following steps: Step S1: The coal slurry to be dehydrated enters a first-stage screen decanter centrifuge through a pipeline for dehydration to obtain first-stage centrifuged coal, first-stage centrifuge liquid, and first-stage filtrate; the first-stage filtrate returns to the first-stage screen decanter centrifuge for further dehydration; Step S2: The first-stage centrifuge in step S1 enters the second-stage screen sedimentation centrifuge for dehydration to obtain second-stage centrifuged coal, second-stage centrifuge and second-stage filtrate; the second-stage filtrate returns to the second-stage screen sedimentation centrifuge for further dehydration. Step S3: The first-stage centrifugal coal in step S1 and the second-stage centrifugal coal in step S4 are mixed and sold.

7. The centrifuge dehydration method according to claim 6, characterized in that: The moisture content of the first-grade centrifugal coal is ≤22% and is directly used as the final product.

8. The centrifuge dehydration method according to claim 6, characterized in that: The first-stage centrifuge liquid discharged from the overflow weir hole at the rear end of the first-stage screen sedimentation centrifuge is transported to the second-stage screen sedimentation centrifuge through a pipeline.

9. The centrifuge dehydration method according to claim 6, characterized in that: The moisture content of the secondary centrifugal coal is ≤24% and is directly used as the final product.

10. The centrifuge dehydration method according to claim 6, characterized in that: The secondary centrifuge liquid discharged from the overflow weir hole at the rear end of the secondary screen sedimentation centrifuge is clarified liquid, which is directly used as circulating water or flushing water.

Images