Waste slurry treatment equipment and method thereof

Abstract

The invention discloses waste slurry treatment equipment and method, and the equipment comprises a waste slurry pool which is used for collecting and preliminarily precipitating waste slurry, and reducing the load of subsequent treatment equipment; the horizontal screw centrifuge is used for primarily separating the waste slurry to separate out most solid particles; the dry flocculation powder coagulant preparation unit is used for preparing a dry flocculation powder coagulant and adding the dry flocculation powder coagulant into the waste slurry to promote flocculation and improve the solid-liquid separation effect; and the plate-and-frame centrifuge is used for deeply separating the flocculated waste slurry to obtain high-purity solid and liquid. According to the waste slurry treatment equipment and method, through the synergistic effect of the waste slurry pool, the horizontal screw centrifugal machine, the dry flocculation powder coagulant preparation unit and the plate-and-frame centrifugal machine, efficient treatment and resource recovery of waste slurry are achieved, and remarkable economic and environmental benefits are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of waste slurry treatment, and particularly relates to waste slurry treatment equipment and a method therefor. Background Art

[0002] In recent years, with the rapid development of urban infrastructure construction in China, there is a large long-term growth space for urban rail transit construction. Since the construction of urban rail transit often passes through densely populated areas or needs to cross rivers and lakes, large-scale surface excavation is not possible. The shield tunneling method has been widely promoted and applied in urban rail transit construction due to its obvious economic and technical advantages and the characteristics of having little impact on the surrounding environment. The shield tunneling method mainly includes various shield construction methods such as compressed air shield, extrusion shield, earth pressure shield, and slurry shield. Currently, the earth pressure shield and slurry shield construction methods are the most commonly used. The slurry shield construction method has the advantages of safety, speed, good waterproof quality, stable excavation surface, high excavation accuracy, etc., and can meet the construction requirements of various complex strata, high water pressure, long distance, and large diameter tunnel projects. It has gradually become the preferred construction method A in tunnel projects crossing rivers and lakes and in complex strata.

[0003] Currently, more and more attention has been paid to the treatment methods of shield waste slurry, and some traditional treatment processes have gradually been extended to shield waste slurry, including traditional plate and frame filtration and centrifugal separation, etc. The traditional plate and frame filtration technology is a commonly used solid-liquid separation device in industry and is widely used in industries such as chemical engineering, sewage, and sludge. The traditional plate and frame filtration treatment is mainly aimed at the treatment of shield waste slurry with a relatively high mud content. Quicklime is added to the waste slurry, and then filter cakes are obtained through pressure filtration. The tail water is discharged up to standard after treatment, and the filter cakes are landfilled. The main advantages of the traditional plate and frame filtration treatment technology are that the water content of the filter cakes is relatively low, generally less than 25%. However, the equipment used occupies a large area, requires high foundation conditions, the treatment process is discontinuous and inefficient, and at the same time, the generated filter cakes and filtrate have a relatively high alkalinity, which is easy to cause secondary pollution to the environment. The mud cakes cannot be recycled and can only be landfilled.

[0004] Therefore, it is urgent to design waste slurry treatment equipment and a method therefor to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide waste slurry treatment equipment and a method therefor to solve the above deficiencies in the prior art.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] Waste slurry treatment equipment, comprising:

[0008] A waste slurry pond: used for collecting and preliminarily precipitating waste slurry to reduce the load on subsequent treatment equipment;

[0009] Horizontal screw centrifuge: used for the preliminary separation of waste slurry to separate out most of the solid particles;

[0010] Dry flocculant preparation unit: used for preparing dry flocculant, which is added to the waste slurry to promote flocculation and improve the solid-liquid separation effect;

[0011] Plate and frame centrifuge: used for the deep separation of the flocculated waste slurry to obtain high-purity solids and liquids;

[0012] Waste slurry treatment method, including the following steps:

[0013] S1. The waste slurry enters the waste slurry tank for preliminary precipitation;

[0014] S2. The precipitated waste slurry is transported into the horizontal screw centrifuge through a feed pump and a flow meter for preliminary separation; the rotational speed of the horizontal screw centrifuge is 2000 - 3000 revolutions per minute, and it is equipped with an automatic cleaning device with a cleaning cycle of once every 8 hours.

[0015] S3. The separated waste slurry is added with the flocculant prepared by the dry flocculant preparation unit through a dosing screw pump for flocculation treatment; the addition amount of the dry flocculant is 0.1% - 0.5% of the weight of the waste slurry, and it is equipped with an automatic metering device with a metering accuracy of ±0.01%.

[0016] S4. The flocculated waste slurry enters the plate and frame centrifuge for deep separation; the rotational speed of the plate and frame centrifuge is 1000 - 1500 revolutions per minute, and it is equipped with an automatic discharging device with a discharging cycle of once every 4 hours.

[0017] Preferably, in S1, the waste slurry generated by each production line is collected and stored through the waste slurry tank to ensure that all the waste slurry produced can be centrally treated. The waste slurry tank is equipped with a stirring device with a stirring speed of 50 - 100 revolutions per minute and a precipitation time of 1 - 2 hours.

[0018] Preferably, in S2, the waste slurry in the waste slurry tank is sent to the horizontal screw centrifuge for treatment. The large particle solids in it are separated from the liquid by the action of centrifugal force to obtain filtrate and separated solid particles, and the solid particles are directly separated by plate and frame filter pressing.

[0019] Preferably, in S3, the filtrate contains large particles, and direct discharge will cause blockage of the liquid outlet of the centrifuge. Therefore, a dry flocculant preparation unit is set at the outlet end of the centrifuge to uniformly and appropriately add flocculant to the filtrate.

[0020] Preferably, in the step S3, the flocculating powder coagulant is sodium carboxymethylcellulose, which promotes the combination of large solid particles and ions in the filtrate to form aggregated particles, avoiding the blockage problem caused by direct discharge of solid particles. The concentration of the added flocculating powder coagulant is 0.1-0.5%, which is optimized according to the filtrate flow rate and the size of solid particles to achieve the best aggregation effect.

[0021] Preferably, in the step S3, the concentration and addition time of the added flocculating powder coagulant are optimized according to the specific working conditions. After the centrifuge treatment, the filtrate flow rate is adjusted to 1-2 m3 / h, and the flocculating powder coagulant is added 30 minutes after the centrifuge starts running to ensure that the solid particles are fully aggregated.

[0022] Preferably, a small amount of large solid particles that are not separated are contained in the filtrate after the centrifuge separation. These filtrates are returned to the waste slurry tank for recycling treatment, and are separated by the centrifuge again to further remove solid particles. This process is repeated until the preset solid content requirement is met.

[0023] Preferably, in the step S3, the treated filtrate enters the sedimentation tank, and the solid particles are gradually aggregated and separated by the flocculating powder coagulant. Finally, the supernatant filtrate that meets the discharge standard is discharged or reused.

[0024] Preferably, in the step S4, after sedimentation in the sedimentation tank, the filter residue is transported to a plate and frame filter press for pressure filtration through a feed pump and a flow meter. The filtrate generated after pressure filtration is discharged or reused, and the dry residue generated is transported out.

[0025] In the above technical solution, the waste slurry treatment equipment and method provided by the present invention realize the efficient treatment and resource recovery of waste slurry through the coordinated action of a waste slurry tank, a horizontal screw centrifuge, a dry flocculating powder coagulant preparation unit, and a plate and frame centrifuge, having significant economic and environmental benefits, improving the disadvantages of traditional treatment methods such as using quicklime, then obtaining a filter cake through pressure filtration, discharging the tail water up to standard, and landfilling the filter cake, and reasonably utilizing Ziyun for resource recycling treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is a process schematic diagram provided for an embodiment of the waste slurry treatment equipment and method of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the drawings.

[0029] As Figure 1 shown, the waste slurry treatment equipment provided by the embodiment of the present invention includes:

[0030] Waste slurry tank: used to collect and preliminarily precipitate waste slurry, reducing the load on subsequent treatment equipment;

[0031] Horizontal screw centrifuge: used to preliminarily separate waste slurry, separating out most of the solid particles;

[0032] Dry flocculant preparation unit: used to prepare dry flocculant, adding it to the waste slurry to promote flocculation and improve the solid-liquid separation effect;

[0033] Plate and frame centrifuge: used to deeply separate the flocculated waste slurry to obtain high-purity solids and liquids.

[0034] Specifically, in this embodiment:

[0035] Specific steps for setting the flocculant preparation unit at the centrifuge outlet: Set the flocculant preparation unit at the outlet end of the horizontal screw centrifuge, and uniformly and appropriately add the flocculant to the filtrate to ensure that solid particles combine with ions in the filtrate to form agglomerated particles.

[0036] Flocculant concentration control: The concentration of the added flocculant is 0.1 - 0.5%, optimized according to the filtrate flow rate and the size of solid particles to achieve the best flocculation effect.

[0037] Centrifuge operation time: After the centrifuge treatment, adjust the filtrate flow rate to 1 - 2 m3 / h, and start adding the flocculant 30 minutes after the centrifuge starts running.

[0038] Flocculant addition time: The flocculant should be added 30 minutes to 1 hour after the centrifuge starts running to ensure that solid particles are fully flocculated.

[0039] Number of circulation treatments: Return the filtrate to the waste slurry tank for circulation treatment, repeating this process until the preset solid content requirement is met, for example, the solid content is less than 0.01%.

[0040] Measures to improve the filtration efficiency of the filter press: During the filtration process of the filter press, adding the flocculant makes the combination of solid particles tighter, thereby improving the filtration efficiency of the filter press and reducing filtration problems caused by blockage of the filter medium or slow filtration speed.

[0041] Filtrate quality control: By monitoring parameters such as the pH value, suspended solid content, and solid particle content of the filtrate, ensure that the filtrate meets the discharge standard and achieves the expected filtration effect.

[0042] Workflow of the recycling treatment system: Return the filtered filtrate to the waste slurry pool to continue the solid particle separation and flocculant treatment, forming a complete closed-loop system to ensure the continuity and stability of the treatment process.

[0043] Connection method between devices: Connect devices such as centrifuges, dry flocculant preparation units, and filter presses through reliable pipelines and connectors to ensure the stable operation of the system.

[0044] Equipment maintenance cycle: Conduct a comprehensive inspection and maintenance of the horizontal scroll centrifuge, filter press, and flocculant preparation unit every quarter to prevent blockage and performance degradation.

[0045] Solid particle separation efficiency: Adjust the rotational speed and rotor gap of the centrifuge to improve the solid particle separation efficiency and ensure the best separation ratio between solid particles and filtrate.

[0046] Control of the flocculant addition amount: After the centrifuge treatment, adjust the filtrate flow rate to 1 - 2 m

[0047] / h, and start adding the flocculant 30 minutes after the centrifuge runs to avoid excessive or insufficient coagulation of solid particles.

[0048] Number of repetitions of the recycling treatment system: After meeting the preset solid content requirements, reduce the number of recycling treatments to reduce the energy consumption and maintenance costs of the system.

[0049] Replacement of the filter medium of the filter press: Regularly replace the filter medium of the filter press to prevent blockage and performance degradation and extend the service life of the equipment.

[0050] Monitoring of quality control parameters: During the recycling treatment process, ensure that the filtrate meets the discharge standards and achieves the expected filtration effect by real-time monitoring of parameters such as the pH value, suspended solid content, and solid particle content of the filtrate.

[0051] Waste slurry treatment method, including the following steps:

[0052] S1. The waste slurry enters the waste slurry pool for preliminary precipitation;

[0053] S2. The precipitated waste slurry is transported into a horizontal scroll centrifuge for preliminary separation through a feed pump and a flow meter; the rotational speed of the horizontal scroll centrifuge is 2000 - 3000 revolutions per minute, and it is equipped with an automatic cleaning device with a cleaning cycle of once every 8 hours.

[0054] S3. The separated waste slurry is added with a flocculant prepared by a dry flocculant preparation unit through a dosing screw pump for flocculation treatment; the addition amount of the dry flocculant is 0.1% - 0.5% of the weight of the waste slurry, and it is equipped with an automatic metering device with a metering accuracy of ±0.01%.

[0055] S4. The flocculated waste slurry enters a plate and frame centrifuge for further separation; the rotational speed of the plate and frame centrifuge is 1000 - 1500 revolutions per minute, and it is equipped with an automatic discharging device with a discharging cycle of once every 4 hours.

[0056] Preferably, in S1, the waste slurry generated by each production line is collected and stored through a waste slurry tank to ensure that all the waste slurry produced can be centrally processed. The waste slurry tank is equipped with a stirring device with a stirring speed of 50 - 100 revolutions per minute and a sedimentation time of 1 - 2 hours.

[0057] Preferably, in S2, the waste slurry in the waste slurry tank is sent to a horizontal screw centrifuge for treatment. The large - particle solids and liquid are separated by the action of centrifugal force to obtain filtrate and separated solid particles, and the solid particles are directly separated by plate - and - frame filtration.

[0058] Preferably, in S3, the filtrate contains large particles, and direct discharge will cause blockage of the liquid outlet of the centrifuge. Therefore, a dry flocculant preparation unit is set at the outlet end of the centrifuge to uniformly and appropriately add flocculant powder to the filtrate.

[0059] Preferably, in S3, the flocculant powder is sodium carboxymethylcellulose, which promotes the combination of large - particle solids and ions in the filtrate to form agglomerated particles, avoiding the blockage problem caused by direct discharge of solid particles. The concentration of the added flocculant powder is 0.1 - 0.5%, which is optimized according to the filtrate flow rate and the size of solid particles to achieve the best agglomeration effect.

[0060] Preferably, in S3, the concentration and addition time of the added flocculant powder are optimized according to the specific working conditions. After the centrifuge treatment, the filtrate flow rate is adjusted to 1 - 2 m³ / h, and the flocculant powder is added 30 minutes after the centrifuge starts running to ensure that the solid particles are fully agglomerated.

[0061] Preferably, the filtrate separated by the centrifuge contains a small amount of large - particle solids that are not separated. These filtrates are returned to the waste slurry tank for recycling treatment, and are separated by the centrifuge again to further remove solid particles. This process is repeated until the preset solid content requirement is met.

[0062] Preferably, in S3, the treated filtrate enters a sedimentation tank. The solid particles are gradually agglomerated and separated by the flocculant powder, and finally the supernatant filtrate that meets the discharge standard is discharged or reused.

[0063] Preferably, in S4, after sedimentation in the sedimentation tank, the filter residue is transported to a plate - and - frame filter press for filtration through a feed pump and a flow meter. The filtrate generated after filtration is discharged or reused, and the dry residue is transported out.

[0064] Example 1

[0065] Waste slurry treatment method, comprising the following steps:

[0066] S1. The waste slurry enters a waste slurry tank for preliminary precipitation;

[0067] S2. The precipitated waste slurry is conveyed into a horizontal screw centrifuge through a feed pump and a flow meter for preliminary separation; the rotational speed of the horizontal screw centrifuge is 2000 - 3000 revolutions per minute, and it is equipped with an automatic cleaning device with a cleaning cycle of once every 8 hours

[0068] S3. The separated waste slurry is added with a flocculant prepared by a dry floc powder coagulant preparation unit through a dosing screw pump for flocculation treatment; the addition amount of the dry floc powder coagulant is 0.1% - 0.5% of the weight of the waste slurry, and it is equipped with an automatic metering device with a metering accuracy of ±0.01%

[0069] S4. The flocculated waste slurry enters a plate and frame centrifuge for deep separation; the rotational speed of the plate and frame centrifuge is 1000 - 1500 revolutions per minute, and it is equipped with an automatic discharging device with a discharging cycle of once every 4 hours.

[0070] Example 2

[0071] This example makes further limitations on the basis of Example 1. In S1, the waste slurry generated by each production line is collected and stored through a waste slurry tank to ensure that all the waste slurry produced in production can be centrally treated. The waste slurry tank is equipped with a stirring device with a stirring speed of 50 - 100 revolutions per minute and a precipitation time of 1 - 2 hours; in S2, the waste slurry in the waste slurry tank is sent to a horizontal screw centrifuge for treatment, and the large - particle solids and liquid therein are separated by the action of centrifugal force to obtain filtrate and separated solid particles, and the solid particles are directly filtered and separated through a plate and frame filter press; in S3, since the filtrate contains large particles and direct discharge will cause blockage of the liquid outlet of the centrifuge, a dry floc powder coagulant preparation unit is set at the outlet end of the centrifuge to uniformly and appropriately add floc powder coagulant to the filtrate; in S3, the floc powder coagulant is sodium carboxymethylcellulose to promote the combination of large - particle solids and ions in the filtrate to form agglomerated particles and avoid the blockage problem caused by direct discharge of solid particles. The added concentration of the floc powder coagulant is 0.1 - 0.5%, which is optimized according to the filtrate flow rate and the size of solid particles to achieve the best agglomeration effect; in S3, the added concentration and time of the floc powder coagulant are optimized according to specific working conditions. After the centrifuge treatment, the filtrate flow rate is adjusted to 1 - 2m

[0072] / h, and start adding flocculant after the centrifuge has been running for 30 minutes to ensure that solid particles are fully flocculated; a small amount of large particle solids that have not been separated are contained in the filtrate after separation by the centrifuge. Return these filtrates to the waste slurry pool for recycling, and separate them again through the centrifuge to further remove solid particles. Repeat this process until the preset solid content requirement is met; in S3, the treated filtrate enters the sedimentation tank, and the solid particles are gradually flocculated and separated by the flocculant. Finally, the supernatant filtrate that meets the discharge standard is discharged or reused; in S4, after sedimentation in the sedimentation tank, the filter residue is transported to the plate and frame filter press for pressure filtration through the feed pump and flow meter. The filtrate generated after pressure filtration is discharged or reused, and the dry residue generated is transported out of the plant.

[0073] Only some exemplary embodiments of the present invention have been described by way of illustration. Without doubt, for those of ordinary skill in the art, the described embodiments can be modified in various different ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. Waste pulp processing equipment, characterized in that: include: Waste slurry pool: used to collect and initially precipitate waste slurry to reduce the load on subsequent processing equipment; Horizontal screw centrifuge: used for preliminary separation of waste slurry and separation of most solid particles; Dry flocculant preparation unit: used to prepare dry flocculant, add it into waste slurry to promote flocculation and improve the solid-liquid separation effect; Plate and frame centrifuge: used to deeply separate the waste slurry after flocculation to obtain high-purity solids and liquids; 2. A method for treating waste pulp, comprising the waste pulp treating device according to claim 1, characterized in that: The following steps are involved: S1, the waste slurry enters the waste slurry tank for preliminary sedimentation; S2. The waste slurry after precipitation is transported into the horizontal screw centrifuge through the slurry pump and flow meter for preliminary separation; the speed of the horizontal screw centrifuge is 2000-3000 rpm, and it is equipped with an automatic cleaning device, and the cleaning cycle is once every 8 hours. S3. The separated waste pulp is added with the flocculant prepared by the dry flocculant preparation unit through a dosing screw pump for flocculation treatment; the amount of the dry flocculant added is 0.1%-0.5% of the weight of the waste pulp, and an automatic metering device is provided with a metering accuracy of ±0.01% S4. The flocculated waste pulp enters a plate and frame centrifuge for deep separation; the rotation speed of the plate and frame centrifuge is 1000-1500 rpm, and an automatic unloading device is provided, and the unloading cycle is once every 4 hours.

3. The method for treating waste pulp according to claim 2, characterized in that: In S1, the waste pulp generated by each production line is collected and stored in a waste pulp pool to ensure that all produced waste pulp can be centrally processed. The waste pulp pool is provided with a stirring device with a stirring speed of 50-100 rpm and a settling time of 1-2 hours.

4. The method for treating waste pulp according to claim 2, characterized in that: In S2, the waste slurry in the waste slurry pool is sent to a horizontal screw centrifuge for processing, and the large solid particles therein are separated from the liquid by centrifugal force to obtain a filtrate and separated solid particles, and the solid particles are directly separated by filtration through a plate and frame filter press.

5. The method for treating waste pulp according to claim 2, characterized in that: In S3, the filtrate contains large particles, and direct discharge will cause blockage of the centrifuge outlet. Therefore, a dry flocculant preparation unit is set at the outlet of the centrifuge to add flocculant evenly and in an appropriate amount to the filtrate.

6. The method for treating waste pulp according to claim 4, characterized in that: In S3, the flocculant is sodium carboxymethyl cellulose, which promotes the combination of large solid particles with ions in the filtrate to form condensed particles and avoids the clogging problem caused by direct discharge of solid particles. The concentration of the added flocculant is 0.1-0.5%, which is optimized according to the filtrate flow rate and the size of the solid particles to achieve the best condensation effect.

7. The method for treating waste pulp according to claim 2, characterized in that: In S3, the concentration and time of adding flocculant are optimized according to the specific working conditions. After the centrifuge treatment, the filtrate flow rate is adjusted to 1-2 m3 / h, and flocculant is added after the centrifuge has been running for 30 minutes to ensure that the solid particles are fully condensed.

8. The method for treating waste pulp according to claim 2, characterized in that: The filtrate after separation by the centrifuge contains a small amount of large solid particles that have not been separated. The filtrate is returned to the waste pulp pool for circulation treatment, and is separated by the centrifuge again to further remove solid particles. This process is repeated until the preset solid content requirement is reached.

9. The method for treating waste pulp according to claim 2, characterized in that: In S3, the treated filtrate enters the sedimentation tank, and the solid particles are gradually coagulated and separated by the flocculant, and finally the supernatant reaches the filtrate of the discharge standard and is discharged or reused.

10. The method for treating waste pulp according to claim 2, characterized in that: In S4, after sedimentation in the sedimentation tank, the filter residue is transported to the plate and frame filter press for filtration through a slurry pump and a flow meter. The filtrate produced after filtration is discharged or reused, and the dry residue produced is transported out. By real-time monitoring of parameters such as the pH value, suspended matter content and solid particle content of the filtrate, it is ensured that the filtrate meets the emission standards and achieves the expected filtering effect.

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