A pressure control method and apparatus for deep mud dewatering process

Abstract

This invention belongs to the field of mud treatment and disposal technology, and discloses a pressurization control method and apparatus for a deep dewatering process of mud. The method includes: after the mud is fed into the dewatering chamber, applying a first pressure P1 using a pressurizing device to perform a first-stage solid-liquid separation; determining the end time of the first-stage solid-liquid separation based on the water pressure in the dewatering chamber, and proceeding to the second-stage solid-liquid separation; during the second-stage solid-liquid separation, applying a second pressure P2 using the pressurizing device, and determining the mud cake thickness L based on a mathematical model of compression amount and compression time. Tc With the second stage pressurization time T c Relationship curve and / or cake compression L c With dehydration time T c The relationship curve is used to determine the pressurization time for the dewatering target. After the pressurization time in the second stage reaches the pressurization time for the dewatering target, the second stage of solid-liquid separation ends. This solves the problem of difficulty in quantitatively controlling key operating parameters such as pressure change nodes and pressure holding time in current slurry deep dewatering devices.

Description

Technical Field

[0001] This invention relates to the field of mud treatment and disposal technology, and in particular to a pressurization control method and apparatus for a deep dewatering process of mud. Background Technology

[0002] Municipal sewage sludge, channel sediment, and river and reservoir silt have high water content and are solid-liquid two-phase mixtures. Furthermore, the fine particle size, high compressibility, and high organic content of these sludge particles result in inefficient solid-liquid separation, hindering subsequent sludge treatment. For sludge with high water content and difficult solid-liquid separation, plate and frame presses are typically used for dewatering. Plate and frame presses consist of multiple plates forming multiple dewatering chambers. Filter cloth is arranged inside the plates and frames. An oil pump drives the plates and frames to squeeze the sludge through the filter cloth, expelling water from the sludge into the dewatering chambers. The pressure applied to the plates and frames is generally set to a stepped variation to increase the water removal rate.

[0003] Pressing equipment offers advantages such as high stability and low energy consumption for dewatering slurry. However, its shortcomings lie in the difficulty of quantifying and controlling key operating parameters such as pressure change points and holding time during the dewatering process. Premature pressurization will put excessive pressure on the filter cloth and frame, leading to significant filter cloth wear and increased slurry leakage; delayed pressurization will reduce overall dewatering efficiency and increase dewatering costs. Therefore, the operation of pressing equipment relies heavily on on-site experience, hindering the development of intelligent equipment control and lacking pressurization control methods for the slurry solid-liquid separation process.

[0004] The working principle of the pressing equipment is to subject the mud to a pressure difference. The non-dissolved solid phase in the mud is intercepted by the filter medium and the gradually forming mud cake, while water passes through the mud cake and filter cloth and is discharged, gradually transforming the solid-liquid mixture into a mud cake with lower water content. The solid-liquid separation of the mud involves two physical process stages. In the first stage, when the mud is filled and pressurized, the external load is mainly borne by the freely flowing water in the mud. Solid phase substances in the mud accumulate on the surface of the filter cloth, and the mud cake gradually forms and thickens until the entire mud mixture is transformed into a mud cake; this stage is the mud cake filtration stage. In the second stage, under pressure, the freely flowing water is gradually discharged, and the load it bears gradually dissipates. The initially formed mud cake structure is loose; under pressure, the solid particles contact each other and bear the load, and the mud cake is compressed and densified, further causing water to be discharged from the pores. The rate of water discharge decreases over time; this stage is the mud cake consolidation stage.

[0005] Since the solid-liquid separation of mud involves a two-stage drainage process, the impact of pressure on the two stages of drainage is different. Therefore, the difficulty in quantitatively controlling key operating parameters such as pressure change points and holding time of mud pressing equipment is a technical problem that urgently needs to be solved. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a pressurization control method and device for the deep dewatering process of mud. The pressurization process can be controlled based on two different drainage mechanisms to solve the problem of difficulty in quantitatively controlling key operating parameters such as pressure change nodes and holding time of current mud pressing equipment.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a pressure control method for a deep dewatering process of mud, the method comprising:

[0009] After the mud is fed into the dewatering chamber, a first pressure P1 is applied using a pressurizing device to carry out the first stage of solid-liquid separation.

[0010] The water pressure in the dehydration chamber is obtained, and the end time of the first stage solid-liquid separation is determined based on the water pressure in the dehydration chamber. After the first stage solid-liquid separation is completed, the second stage solid-liquid separation begins.

[0011] During the second stage of solid-liquid separation, a second pressure P2 is applied using a pressurizing device, and the pressurization time and water discharge volume of the second stage are obtained.

[0012] Based on a mathematical model of compression amount and compression time, the cake thickness L is determined according to the pressurization time and water discharge volume during the second-stage solid-liquid separation. Tc With the second stage pressurization time T c Relationship curve and / or cake compression L c With dehydration time T c Relationship curve;

[0013] According to the thickness L of the mud cake Tc With the second stage pressurization time T c Relationship curve and / or cake compression L c With dehydration time T c The relationship curve is used to determine the pressurization time for the dehydration target. After the pressurization time in the second stage reaches the pressurization time for the dehydration target, the second stage of solid-liquid separation ends.

[0014] Furthermore, the first pressure P1 can ensure the drainage rate without damaging the filter cloth.

[0015] Further, the water pressure within the dehydration chamber is obtained, and the end time of the first stage of solid-liquid separation is determined based on the water pressure within the dehydration chamber. After the first stage of solid-liquid separation is completed, the second stage of solid-liquid separation begins, including:

[0016] During the first stage of solid-liquid separation, the water pressure in the dehydration chamber increases and stabilizes at a first set pressure P within a set time.w1 Wherein, the first set pressure P w1 Determined by the first pressure P1;

[0017] When the water pressure in the dehydration chamber begins to drop and reaches the second set pressure P w2 Then, the second stage of solid-liquid separation begins.

[0018] Furthermore, the first set pressure P w1 It is calculated by subtracting the pressure loss from the first pressure P1.

[0019] Furthermore, the mathematical model for the compression amount and compression time is expressed as follows:

[0020]

[0021] In the formula, T c For the second stage of pressurization time; L Tc For T c The thickness of the mud cake at the beginning of the second stage; L1 is the thickness of the mud cake at the beginning of the second stage; L * With T c * C represents the ultimate cake compression amount and required time under load P2; e C is a coefficient. e =0.848ω 2 / (0.9i 2 T c * ); ω is the solid volume per unit area, ω=m / ρ, m is the solid mass in the mud, ρ is the solid particle density; i is the drainage surface, 1 for single-sided drainage and 2 for double-sided drainage; B, F and η are model parameters, B=1-F, the model parameters are determined by small-scale loading dewatering test.

[0022] Furthermore, the second pressure P2 is greater than or equal to the first pressure P1.

[0023] Secondly, the present invention provides a pressurization control device for a deep dewatering process of mud, the device comprising a dewatering chamber, a pressurization device, a pressure sensor, and a control terminal; wherein the pressurization device is connected to the dewatering chamber and is used to apply a load to the dewatering chamber, the pressure sensor is disposed within the dewatering chamber, and the control terminal is signal-connected to the pressurization device and the pressure sensor, the control terminal being configured to:

[0024] After the mud is fed into the dewatering chamber, a first pressure P1 is applied using a pressurizing device to carry out the first stage of solid-liquid separation.

[0025] The water pressure in the dehydration chamber is obtained, and the end time of the first stage solid-liquid separation is determined based on the water pressure in the dehydration chamber. After the first stage solid-liquid separation is completed, the second stage solid-liquid separation begins.

[0026] During the second stage of solid-liquid separation, a second pressure P2 is applied using a pressurizing device, and the pressurization time and water discharge volume of the second stage are obtained.

[0027] Based on a mathematical model of compression amount and compression time, the cake thickness L is determined according to the pressurization time and water discharge volume during the second-stage solid-liquid separation. Tc With the second stage pressurization time T c Relationship curve and / or cake compression L c With dehydration time T c Relationship curve;

[0028] According to the thickness L of the mud cake Tc With the second stage pressurization time T c Relationship curve and / or cake compression L c With dehydration time T c The relationship curve is used to determine the pressurization time for the dehydration target. After the pressurization time in the second stage reaches the pressurization time for the dehydration target, the second stage of solid-liquid separation ends.

[0029] Furthermore, the control terminal is further configured as follows:

[0030] During the first stage of solid-liquid separation, the water pressure in the dehydration chamber increases and stabilizes at a first set pressure P within a set time. w1 Wherein, the first set pressure P w1 Determined by the first pressure P1;

[0031] When the water pressure in the dehydration chamber begins to drop and reaches the second set pressure P w2 Then, the second stage of solid-liquid separation begins.

[0032] Furthermore, the first set pressure P w1 It is calculated by subtracting the pressure loss from the first pressure P1.

[0033] Furthermore, the mathematical equation relating the compression amount to the compression time is expressed as follows:

[0034]

[0035] In the formula, T c For the second stage of pressurization time; L Tc For T c The thickness of the mud cake at the beginning of the second stage; L1 is the thickness of the mud cake at the beginning of the second stage; L * With Tc * C represents the ultimate cake compression amount and required time under load P2; e C is a coefficient. e =0.848ω 2 / (0.9i 2 T c * ); ω is the solid volume per unit area, ω=m / ρ, m is the solid mass in the mud, ρ is the solid particle density; i is the drainage surface, 1 for single-sided drainage and 2 for double-sided drainage; B, F and η are model parameters, B=1-F, the model parameters are determined by small-scale loading dewatering test.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] Currently, the solid-liquid separation process of slurry in pressing equipment is often treated as a black box, relying heavily on on-site experience to determine pressure change points and holding times. This presents a challenge in quantifying key parameters of the solid-liquid separation process, limiting the intelligent development of equipment control. This invention proposes a pressurization control method and device for the slurry solid-liquid separation process. Based on the drainage mechanism at different stages of the slurry solid-liquid separation process, it determines the transition time points of the solid-liquid separation stages by analyzing water pressure changes, thereby determining the pressure gradient adjustment points. This avoids premature pressurization leading to filter cloth wear and slurry leakage failure, as well as delayed pressurization resulting in low dewatering efficiency. Simultaneously, a mathematical model is used to obtain the quantitative relationship between cake thickness, compression amount, moisture content, and dewatering time, thus determining the pressurization time to achieve the dewatering target. This invention helps determine the key parameters of slurry solid-liquid separation in pressing equipment, reducing reliance on experience and improving intelligent control capabilities. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0039] Figure 1 This is a flowchart of a pressure control method for a deep dewatering process of mud, provided as an embodiment of the present invention.

[0040] Figure 2 The relationship between dewatering volume V and dewatering time T of LS and BX sludge under different P1 conditions is provided in the embodiments of the present invention; wherein, (a) LS sludge; (b) BX sludge.

[0041] Figure 3The water pressure P in the dewatering chambers of LS and BX sludge under different P1 conditions provided in the embodiments of the present invention is as follows: w Changes; (a) LS sludge; (b) BX sludge.

[0042] Figure 4 The sludge cake compression L of BX sludge provided in this embodiment of the invention under loads of P2 = 0.4 MPa and 0.8 MPa. c With the second stage compression time T c The relationship is as follows: (a) P2 = 0.4 MPa; (b) P2 = 0.8 MPa.

[0043] Figure 5 This is a structural diagram of a pressure control device for a deep dewatering process of mud, provided in an embodiment of the present invention. Detailed Implementation

[0044] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0045] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying their relative importance.

[0046] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] The invention will now be further described with reference to the accompanying drawings.

[0048] This invention provides a pressure control method for deep mud dewatering, aiming to improve the management and control level of the mud pressing and dewatering process and better control the cost input in the mud dewatering process. This invention implements the pressure control method based on the following principles:

[0049] In the first stage, the discharged water mainly consists of freely flowing water in the mud under pressure. The external load is primarily borne by this free-flowing water and can be monitored by a pore water pressure sensor. Water passes through the mud cake and filter cloth and is discharged at a relatively high rate. Excessive pressure can lead to significant filter cloth wear, and filter cloth damage can cause mud leakage and dewatering failure. In the second stage, the free-flowing water discharge ends, the water pressure decreases, and the mud cake gradually bears the load. The drainage mechanism mainly involves the mud cake being compressed and densified, squeezing out water from the pores. The water discharge rate decreases over time. Increasing the pressure in this stage helps accelerate mud cake compression and improve the drainage rate. The transition point between the two stages is the time to adjust the pressure. Furthermore, the mud cake compression deformation in the second stage can be described by a mathematical model, which can be used to determine the pressurization time.

[0050] Figure 1 This is a flowchart illustrating a pressure control method for a deep mud dewatering process, provided as an embodiment of the present invention. The pressure control method for the deep mud dewatering process includes the following steps S10 to S50.

[0051] S10: After the mud is fed into the dewatering chamber, the first pressure P1 is applied using a pressurizing device to carry out the first stage of solid-liquid separation.

[0052] S20: Obtain the water pressure in the dehydration chamber, determine the end time of the first stage solid-liquid separation based on the water pressure in the dehydration chamber, and proceed to the second stage solid-liquid separation after the first stage solid-liquid separation is completed.

[0053] In one exemplary embodiment, after the slurry is pumped into the dewatering chamber, a pressurizing device applies a load of P1 to initiate the first stage of solid-liquid separation. The value of P1 is set to ensure a sufficient drainage rate without causing filter cloth wear. Water pressure sensors arranged within the dewatering chamber monitor the changes in water pressure during the solid-liquid separation process. The water pressure rises rapidly and stabilizes at a first set pressure P. w1 Due to pressure loss, the first set pressure P w1 Slightly less than P1, therefore the first set pressure P w1 The calculation can be performed based on the pressure loss generated when the pressurizing equipment applies the first pressure P1.

[0054] As pressure dehydration proceeds, when the water pressure becomes unstable (P) w The initial drop in water pressure indicates that the first stage is nearing its end. A 5% decrease in water pressure is considered to have reached the second set pressure P.w2 At this point, the second stage of solid-liquid separation begins.

[0055] S30: During the second stage of solid-liquid separation, a second pressure P2 is applied using a pressurizing device, and the pressurization time and water discharge volume of the second stage are obtained.

[0056] S40: Based on a mathematical model of compression amount and compression time, the cake thickness L is determined according to the pressurization time and water discharge volume of the second-stage solid-liquid separation. Tc With the second stage pressurization time T c Relationship curve and / or cake compression L c With dehydration time T c The relationship curve.

[0057] In an exemplary embodiment, the compression amount and compression time after entering the second stage are governed by the following mathematical model:

[0058]

[0059] In the formula, T c For the second stage of pressurization time; L Tc For T c The thickness of the mud cake at the beginning of the second stage; L1 is the thickness of the mud cake at the beginning of the second stage; L * With T c * C represents the ultimate cake compression amount and required time under load P2; e C is a coefficient. e =0.848ω 2 / (0.9i 2 T c * ); ω is the solid volume per unit area, ω=m / ρ, m is the solid mass in the mud, ρ is the solid particle density; i is the drainage surface, 1 for single-sided drainage and 2 for double-sided drainage; B, F and η are model parameters, B=1-F, the model parameters are determined by small-scale loading dewatering test.

[0060] S50: According to the thickness L of the mud cake Tc With the second stage pressurization time T c Relationship curve and / or cake compression L c With dehydration time T c The relationship curve is used to determine the pressurization time for the dehydration target. After the pressurization time in the second stage reaches the pressurization time for the dehydration target, the second stage of solid-liquid separation ends.

[0061] In an exemplary embodiment, the mud cake thickness L can be drawn using Equation 1. Tc With the second stage pressurization time T c The relationship curve can also be converted into the amount of mud cake compression L.c With dehydration time T c Relationship curve, L Tc or L c The rate of decrease with T c Increase and decrease, according to L Tc -T c or L c -T c The pressure time required to achieve the dehydration target can be determined from the relationship curve.

[0062] To further illustrate the feasibility and advancement of the method proposed in this invention, a specific case will be used to illustrate it in detail below. It should be noted that specific experimental parameters will be involved in the following case; these experimental parameters are exemplary and do not imply that the pressure control method must be performed according to these experimental parameters.

[0063] The equipment used was a laboratory-scale pressing and dewatering simulation test apparatus. The dewatering chamber was a cylindrical chamber with an inner diameter of 9 cm, and the filter medium was a circular filter cloth of the same diameter. Two types of municipal wastewater sludge, LS and BX, were used for the test. The moisture content of both types of sludge was 84%, and the mass of the sludge to be dewatered was approximately 205 g. After the sludge was loaded into the dewatering chamber, a constant load P1 was applied for dewatering tests. The applied loads P1 for six tests were 0.05 MPa, 0.4 MPa, 0.8 MPa, 1.2 MPa, 1.6 MPa, and 2 MPa, respectively. The dewatering volume was monitored in real time immediately after the load was applied, and the water pressure was monitored in real time using a water pressure sensor placed in the dewatering chamber.

[0064] The trends of dewatering volume V of the two types of sludge under 6 loads as a function of dewatering time T are as follows: Figure 2 As shown, the dehydrated volume tends to stabilize with increasing dehydration time. The water pressure monitoring pattern is as follows: Figure 3 As shown, the water pressure rises and stabilizes at P in a short period of time. w1 Due to pressure loss P w1 Slightly less than P1. As dehydration proceeds, when the water pressure no longer stabilizes at P... w1 The temperature begins to drop, indicating that the first stage is about to end, and the second stage of solid-liquid separation begins. Figure 3 As indicated by the middle arrow. Dehydration tests show that water pressure monitoring during dehydration can effectively determine the stage of the dehydration process.

[0065] After entering the second stage of solid-liquid separation, this test uses P2 = P1, keeping the external load constant. The cake compression amount L is calculated using Equation 1. c With the second stage pressurization time T c The relationship curves are shown in Table 1, and the model parameters of Equation 1 are shown in Table 1. Some results are as follows. Figure 4As shown. The relationship curve calculated by the model in Equation 1 closely approximates the experimental curve. This indicates that L calculated according to Equation 1... c -T c The relationship curve can determine the pressurization time to achieve the dehydration target.

[0066] Table 1. Equation 1. Model Parameter Assignment

[0067]

[0068]

[0069] This invention also provides a pressure control device for the deep dewatering process of mud, such as... Figure 5 As shown, the pressurization control device for the deep dewatering process of mud includes a dewatering chamber 501, a pressurization device 502, a pressure sensor 503, and a control terminal 504; wherein, the pressurization device 502 is connected to the dewatering chamber 501 and is used to apply a load to the dewatering chamber 501, the pressure sensor 503 is disposed inside the dewatering chamber 501, and the control terminal 504 is signal-connected to the pressurization device 502 and the pressure sensor 503, and the control terminal 504 is configured to:

[0070] After the mud is fed into the dewatering chamber, a first pressure P1 is applied using a pressurizing device to carry out the first stage of solid-liquid separation.

[0071] The water pressure in the dehydration chamber is obtained, and the end time of the first stage solid-liquid separation is determined based on the water pressure in the dehydration chamber. After the first stage solid-liquid separation is completed, the second stage solid-liquid separation begins.

[0072] During the second stage of solid-liquid separation, a second pressure P2 is applied using a pressurizing device, and the pressurization time and water discharge volume of the second stage are obtained.

[0073] Based on a mathematical model of compression amount and compression time, the cake thickness L is determined according to the pressurization time and water discharge volume during the second-stage solid-liquid separation. Tc With the second stage pressurization time T c Relationship curve and / or cake compression L c With dehydration time T c Relationship curve;

[0074] According to the thickness L of the mud cake Tc With the second stage pressurization time T c Relationship curve and / or cake compression L c With dehydration time T c The relationship curve is used to determine the pressurization time for the dehydration target. After the pressurization time in the second stage reaches the pressurization time for the dehydration target, the second stage of solid-liquid separation ends.

[0075] In some embodiments, the control terminal 504 is further configured to:

[0076] During the first stage of solid-liquid separation, the water pressure in the dehydration chamber increases and stabilizes at a first set pressure P within a set time. w1 Wherein, the first set pressure P w1 Determined by the first pressure P1;

[0077] When the water pressure in the dehydration chamber begins to drop and reaches the second set pressure P w2 Then, the second stage of solid-liquid separation begins.

[0078] In some embodiments, the first set pressure P w1 It is calculated by subtracting the pressure loss from the first pressure P1.

[0079] In some embodiments, the mathematical model of the compression amount and compression time is expressed as follows:

[0080]

[0081] In the formula, T c For the second stage of pressurization time; L Tc For T c The thickness of the mud cake at the beginning of the second stage; L1 is the thickness of the mud cake at the beginning of the second stage; L * With T c * C represents the ultimate cake compression amount and required time under load P2; e C is a coefficient. e =0.848ω 2 / (0.9i 2 T c * ); ω is the solid volume per unit area, ω=m / ρ, m is the solid mass in the mud, ρ is the solid particle density; i is the drainage surface, 1 for single-sided drainage and 2 for double-sided drainage; B, F and η are model parameters, B=1-F, the model parameters are determined through small-scale loading dewatering tests.

[0082] It should be noted that the pressurization control device for the deep dewatering process of mud provided in this embodiment of the invention belongs to the same technical concept as the prior pressurization control method for the deep dewatering process of mud. They are based on similar technical principles and can achieve the same technical effect, which will not be elaborated here.

[0083] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A pressure control method for a deep dewatering process of mud, characterized in that, The method includes: After the mud is fed into the dewatering chamber, a first pressure P1 is applied using a pressurizing device to carry out the first stage of solid-liquid separation. The water pressure in the dehydration chamber is obtained, and the end time of the first stage solid-liquid separation is determined based on the water pressure in the dehydration chamber. After the first stage solid-liquid separation is completed, the second stage solid-liquid separation begins. During the second stage of solid-liquid separation, a second pressure P2 is applied using a pressurizing device, and the pressurization time and water discharge volume of the second stage are obtained. Based on a mathematical model of compression amount and compression time, the cake thickness L is determined according to the pressurization time and water discharge volume during the second-stage solid-liquid separation. Tc With the second stage pressurization time T c Relationship curve and / or cake compression L c With dehydration time T c Relationship curve; According to the thickness L of the mud cake Tc With the second stage pressurization time T c Relationship curve and / or cake compression L c With dehydration time T c The relationship curve is used to determine the pressurization time for the dehydration target. After the pressurization time in the second stage reaches the pressurization time for the dehydration target, the second stage of solid-liquid separation ends. Obtain the water pressure within the dehydration chamber, determine the end time of the first stage of solid-liquid separation based on the water pressure within the dehydration chamber, and proceed to the second stage of solid-liquid separation after the first stage of solid-liquid separation is completed, including: During the first stage of solid-liquid separation, the water pressure in the dehydration chamber increases and stabilizes at a first set pressure P within a set time. w1 Wherein, the first set pressure P w1 Determined by the first pressure P1; When the water pressure in the dehydration chamber begins to drop and reaches the second set pressure P w2 At this point, the second stage of solid-liquid separation begins; The mathematical model for the compression amount and compression time is expressed as follows: (Equation 1) In the formula, T c For the second stage of pressurization time; L Tc For T c The thickness of the mud cake at the beginning of the second stage; L1 is the thickness of the mud cake at the beginning of the second stage; L * With T c * C represents the ultimate cake compression amount and required time under load P2; e C is a coefficient. e =0.848ω 2 / (0.9i 2 T c * ); ω is the solid volume per unit area, ω=m / ρ, m is the solid mass in the mud, ρ is the solid particle density; i is the drainage surface, 1 for single-sided drainage and 2 for double-sided drainage; B, F and η are model parameters, B=1-F, and the model parameters are determined by small-scale loading dewatering test.

2. The pressurization control method for deep dewatering of mud according to claim 1, characterized in that, The first pressure P1 can ensure the drainage rate without damaging the filter cloth.

3. The pressurization control method for deep dewatering of mud according to claim 1, characterized in that, The first set pressure P w1 It is calculated by subtracting the pressure loss from the first pressure P1.

4. The pressure control method for deep dewatering of mud according to claim 1, characterized in that, The second pressure P2 is greater than or equal to the first pressure P1.

5. A pressure control device for a deep dewatering process of mud, characterized in that, The device includes a dehydration chamber, a pressurizing device, a pressure sensor, and a control terminal; wherein, the pressurizing device is connected to the dehydration chamber and is used to apply a load to the dehydration chamber; the pressure sensor is disposed inside the dehydration chamber; the control terminal is signal-connected to the pressurizing device and the pressure sensor; and the control terminal is configured to: After the mud is fed into the dewatering chamber, a first pressure P1 is applied using a pressurizing device to carry out the first stage of solid-liquid separation. The water pressure in the dehydration chamber is obtained, and the end time of the first stage solid-liquid separation is determined based on the water pressure in the dehydration chamber. After the first stage solid-liquid separation is completed, the second stage solid-liquid separation begins. During the second stage of solid-liquid separation, a second pressure P2 is applied using a pressurizing device, and the pressurization time and water discharge volume of the second stage are obtained. Based on a mathematical model of compression amount and compression time, the cake thickness L is determined according to the pressurization time and water discharge volume during the second-stage solid-liquid separation. Tc With the second stage pressurization time T c Relationship curve and / or cake compression L c With dehydration time T c Relationship curve; According to the thickness L of the mud cake Tc With the second stage pressurization time T c Relationship curve and / or cake compression L c With dehydration time T c The relationship curve is used to determine the pressurization time for the dehydration target. After the pressurization time in the second stage reaches the pressurization time for the dehydration target, the second stage of solid-liquid separation ends. The control terminal is further configured as follows: During the first stage of solid-liquid separation, the water pressure in the dehydration chamber increases and stabilizes at a first set pressure P within a set time. w1 Wherein, the first set pressure P w1 Determined by the first pressure P1; When the water pressure in the dehydration chamber begins to drop and reaches the second set pressure P w2 At this point, the second stage of solid-liquid separation begins; The mathematical model for the compression amount and compression time is expressed as follows: (Equation 1) In the formula, T c For the second stage of pressurization time; L Tc For T c The thickness of the mud cake at the beginning of the second stage; L1 is the thickness of the mud cake at the beginning of the second stage; L * With T c * C represents the ultimate cake compression amount and required time under load P2; e C is a coefficient. e =0.848ω 2 / (0.9i 2 T c * ); ω is the solid volume per unit area, ω=m / ρ, m is the solid mass in the mud, ρ is the solid particle density; i is the drainage surface, 1 for single-sided drainage and 2 for double-sided drainage; B, F and η are model parameters, B=1-F, and the model parameters are determined by small-scale loading dewatering test.

6. The pressurization control device for deep dewatering of mud according to claim 5, characterized in that, The first set pressure P w1 It is calculated by subtracting the pressure loss from the first pressure P1.

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