Sludge efficient dehydration conditioning method and device based on multi-pulse detonation shock waves

Abstract

The invention discloses an efficient sludge dehydration conditioning method and device based on multi-pulse detonation shock waves, and relates to the technical field of sewage treatment, and the method comprises the steps of sludge pretreatment, multi-pulse detonation shock and energy recovery dehydration. Wherein the stepped pressure in the multi-pulse detonation impact is 0.5-4.0 MPa, and the pulse frequency is 1-10 Hz. The porous impact plate is arranged in the spherical detonation bin, the pulse electromagnetic valve is arranged on a pipeline, leading to the spherical detonation bin, of the high-pressure gas storage tank, and the porous impact plate is arranged at the outlet end of the pipeline. The energy recovery system comprises a residual pressure converter and a heat recovery pipe, the residual pressure converter pressurizes the mud cake, and the heat recovery pipe is used for heating the inlet sludge; the intelligent control system regulates and controls the pulse frequency and the pressure gradient through a PLC. According to the method, pulse type detonation shock waves with the controllable frequency of 1-10 Hz are adopted, a sludge extracellular polymeric substance (EPS) net structure is disintegrated layer by layer through the pressure accumulation effect, and energy waste caused by single-time impact is avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of sludge treatment, and specifically relates to a device and method for destroying the sludge microstructure and improving the dewatering performance through multi-frequency pulsed detonation shock waves. The device is particularly suitable for the pretreatment of high-water content municipal sludge and oily sludge. Background Art

[0002] Defects of existing technology:

[0003] (1) Physical methods have low efficiency and high energy consumption

[0004] Ultrasonic conditioning technology relies on the cavitation effect, but the energy consumption is as high as 1.2kWh / m when treating sludge with a moisture content of 98%. 3 , the capillary suction time (CST) is only reduced by 30% (data source: Journal of Environmental Engineering, 2020); the power consumption of traditional high-pressure filter presses is 5-8kWh / ton of sludge, and the moisture content of the sludge cake is still higher than 65% ("Technical Regulations for Sludge Treatment of Urban Wastewater Treatment Plants" CJJ131-2017).

[0005] (2) Chemical methods are costly and pollute the environment

[0006] Fenton oxidation method requires the addition of Fe 2+ (0.1mol / L) and H2O2 (0.3mol / L), the treatment cost is greater than 2 yuan / ton, and the sludge calorific value loss is greater than 25%.

[0007] (3) Thermal method equipment is complex

[0008] Steam explosion technology (CN201410263484A) requires maintaining a high temperature above 120°C, with an equipment corrosion rate of >3mm / year and a heat loss of 15%.

[0009] Knock regulation technology gap:

[0010] The instantaneous ultra-high pressure (microsecond pressure peak) generated by detonation can effectively destroy sludge flocs and cell walls, but existing research has mostly used it for soil remediation or ore crushing, and has not seen its application in the field of sludge dewatering. In particular, the problem of multi-scale structural destruction in sludge dewatering has not been solved, and there is a lack of energy recycling design. Summary of the Invention

[0011] In response to the shortcomings of the existing technology, the present invention provides a sludge efficient dehydration and conditioning device and method based on multi-pulse detonation shock waves. The method of the present invention adopts a pulsed detonation shock wave with a controllable frequency of 1-10Hz, and uses the pressure accumulation effect to break down the sludge extracellular polymer EPS network structure layer by layer, thereby avoiding the waste of single impact energy.

[0012] The present invention achieves the above technical objectives through the following technical means.

[0013] A method for efficient sludge dehydration and conditioning based on multi-pulse detonation shock waves, including sludge pretreatment, multi-pulse detonation shock and energy recovery dehydration; wherein the multi-pulse detonation shock has a step pressure of 0.5-4.0 MPa and a pulse frequency of 1-10 Hz.

[0014] In the above scheme, the multi-pulse detonation shock includes three stages, among which the first stage: 0.5MPa shock × (3~6) times, with an interval of 2s, to destroy the outer EPS; the second stage: 2.0MPa shock × (3~5) times, with an interval of 5s, to break the microbial cells; the third stage: 3.5~4MPa shock × 1 time to release bound water.

[0015] In the above scheme, energy recovery and dehydration: the residual pressure is used to drive the filter press, with a pressure of 0-12MPa, to obtain a mud cake with a moisture content of ≤55%, and the residual heat is used to preheat the sludge to 40-50℃.

[0016] In the above scheme, sludge pretreatment: sludge with a moisture content of 95% to 99% is pumped into the spherical detonation chamber, left to stand for 5-20 minutes, the supernatant is discharged, and then filled again.

[0017] A device for a highly efficient sludge dewatering and conditioning method based on multi-pulse detonation shock waves, comprising a pulsed detonation main reaction chamber, an energy recovery system, and an intelligent control system;

[0018] Among them, the pulse detonation main reaction chamber includes a high-pressure gas storage tank, a pulse solenoid valve and a porous impact plate, wherein the porous impact plate is arranged in the spherical detonation chamber, the pulse solenoid valve is arranged on the pipeline leading from the high-pressure gas storage tank to the spherical detonation chamber, and the outlet end of the pipeline is provided with a porous impact plate;

[0019] The energy recovery system includes a residual pressure converter and a heat recovery pipe, wherein the residual pressure converter pressurizes the mud cake and the heat recovery pipe is used for heating the sludge;

[0020] The intelligent control system regulates the pulse frequency and pressure gradient through PLC.

[0021] In the above scheme, the energy recovery system is connected to the spherical detonation chamber through a pipeline. A heat recovery pipe is provided on one side of the pipeline, and a residual pressure converter and a residual pressure driven filter press are provided at the output end of the pipeline in sequence. The heat recovery pipe is a 316L stainless steel spiral pipe with a heat transfer coefficient of ≥120W / (m 2 ·K).

[0022] In the above solution, the porous impact plate is uniformly distributed with conical micropores, and the inlet diameter D1 and outlet diameter D2 of the conical micropores satisfy D1 / D2=3-5.

[0023] In the above solution, the high-pressure gas storage tank is equipped with a vortex refrigeration device to maintain the gas temperature at -10°C to 5°C.

[0024] In the above scheme, the outermost side of the spherical detonation chamber is the detonation cavity wall, and the outer wall of the device is provided outside the detonation cavity wall. Shock-absorbing and sound-absorbing filling materials are filled between the detonation cavity wall and the outer wall of the device; the outer wall of the device is provided on a shock-absorbing bracket, and a lifting ring is provided on the outer wall of the device.

[0025] In the above scheme, the spherical detonation chamber is also connected to a mud inlet pipe and a sludge discharge pipe, wherein the mud inlet pipe is provided with a mud inlet control valve and a flexible shock-absorbing valve, and the sludge discharge pipe is provided with a mud discharge valve and a flexible shock-absorbing valve; the liquid level and pressure in the spherical detonation chamber are monitored by a liquid level sensor and a pressure sensor.

[0026] Beneficial effects:

[0027] Dehydration performance breakthrough: After conditioning by this device, the moisture content of the sludge dewatering cake is reduced from 98% to 50-55%, which is 10-15% lower than the traditional ultrasonic conditioning method;

[0028] Energy consumption advantage: The energy recovery system reduces total energy consumption by 30%, and the unit processing cost is less than 0.5 yuan / ton;

[0029] Zero chemical addition: pure physical action, no chemical addition, sludge calorific value retention rate > 95%, conducive to subsequent incineration disposal.

[0030] The device of the present invention has a compact structure, is convenient for hoisting and moving, and improves the comfort during use by arranging shock-absorbing and sound-absorbing filling materials.

[0031] The method of the present invention further reduces the moisture content of the mud cake by arranging an energy recovery dehydration step and preheats the incoming mud and sewage, thereby improving the utilization rate of energy.

[0032] A porous impact plate is provided in the device of the present invention. The porous plate mainly releases the gas in the high-pressure gas storage tank into the detonation chamber evenly and in a very short time to form a detonation reaction. The holes on the porous plate mainly play a role in uniform gas distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the structure of a sludge high-efficiency dewatering and conditioning device based on multi-pulse detonation shock waves;

[0034] Figure 2 Schematic diagram of a porous impact plate involved in the embodiment.

[0035] Reference numerals:

[0036] 1-Spherical detonation chamber; 2-Detonation chamber wall; 3-Porous impact plate; 4-Shock-absorbing and sound-absorbing filling material; 5-Shock-absorbing bracket; 6-Foundation and bracket; 7-Outer wall of the device; 8-Lifting ring; 9-Heat recovery pipe; 10-Residual pressure converter; 11-Residual pressure driven filter press; 12-Pressure sensor; 13-Liquid level sensor; 14-First flexible shock-absorbing valve; 15-Mud inlet control valve; 16-Mud inlet pipe; 17-Exhaust valve; 18-Decompression chamber; 19-Decompression valve; 20-Pulse solenoid valve; 21-High-pressure gas storage tank; 22-Sludge discharge pipe; 23-Sludge discharge valve; 24-Second flexible shock-absorbing valve. DETAILED DESCRIPTION

[0037] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0038] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0039] A highly efficient sludge dewatering and conditioning method based on multi-pulse detonation shock waves includes sludge pretreatment, multi-pulse detonation shock waves, and energy recovery dewatering. The multi-pulse detonation shock waves have a step pressure of 0.5-4.0 MPa and a pulse frequency of 1-10 Hz. The multi-pulse detonation shock waves consist of three stages: the first stage: 3-6 shocks at 0.5 MPa, with 2-second intervals, to destroy the outer EPS layer; the second stage: 3-5 shocks at 2.0 MPa, with 5-second intervals, to disrupt microbial cells; and the third stage: 1 shock at 3.5-4 MPa, to release bound water.

[0040] Energy recovery dehydration: The filter press 11 is driven by the residual pressure at a pressure of 0-12 MPa to obtain a mud cake with a moisture content of ≤55%. The residual heat is used to preheat the sludge to 40-50°C.

[0041] Sludge pretreatment: Pump sludge with a moisture content of 95%-99% into the spherical detonation chamber 1, let it stand for 5-20 minutes, drain the supernatant, and then fill it up again.

[0042] Multi-pulse detonation shock wave sludge high-efficiency dewatering conditioning device, including a pulse detonation main reaction chamber, an energy recovery module and an intelligent control system;

[0043] The pulse detonation main reaction chamber includes a high-pressure gas storage tank 21, a pulse solenoid valve 20 and a porous impact plate 3, wherein the porous impact plate 3 is arranged in the spherical detonation chamber 1, and the pulse solenoid valve 20 is arranged on the pipeline from the high-pressure gas storage tank 21 to the spherical detonation chamber 1, and the porous impact plate 3 is provided at the outlet end of the pipeline;

[0044] The energy recovery system includes a residual pressure converter 10 and a heat recovery pipe 9, wherein the residual pressure converter 10 pressurizes the mud cake, and the heat recovery pipe 9 is used for heating the sludge;

[0045] Intelligent control system controls pulse frequency and pressure gradient through PLC

[0046] The energy recovery system is connected to the spherical detonation chamber 1 through a pipeline. A heat recovery pipe 9 is provided on one side of the pipeline. A residual pressure converter 10 and a residual pressure driven filter press 11 are provided at the output end of the pipeline in sequence. The heat recovery pipe 9 is a 316L stainless steel spiral pipe with a heat transfer coefficient of ≥120W / (m 2 ·K).

[0047] The inlet diameter D1 and outlet diameter D2 of the tapered micropore satisfy D1 / D2=3-5.

[0048] The high-pressure gas storage tank 21 is equipped with a vortex refrigeration device to maintain the gas temperature at -10°C to 5°C.

[0049] The outermost side of the spherical detonation chamber 1 is the detonation cavity wall 2, and an apparatus outer wall 7 is provided outside the detonation cavity wall 2. Shock-absorbing and sound-absorbing filling materials 4 are filled between the detonation cavity wall 2 and the apparatus outer wall 7; the apparatus outer wall 7 is provided on a shock-absorbing bracket 5, and a lifting ring 8 is provided on the apparatus outer wall 7.

[0050] The spherical detonation chamber 1 is also connected to a mud inlet pipe 16 and a sludge discharge pipe 22, wherein the mud inlet pipe 16 is provided with a mud inlet control valve 15 and a first flexible shock-absorbing valve 14, and the sludge discharge pipe 22 is provided with a mud discharge valve 23 and a second flexible shock-absorbing valve 24; the liquid level and pressure in the spherical detonation chamber are monitored by a liquid level sensor 13 and a pressure sensor 12.

[0051] 1. Conditioning method

[0052] (1) Multi-pulse detonation shock control:

[0053] It uses a pulsed detonation shock wave with a controllable frequency of 1-10Hz to break down the extracellular polymeric substances (EPS) network structure of the sludge layer by layer through the pressure accumulation effect, thus avoiding the waste of energy in a single impact.

[0054] Set a stepped pressure gradient, 0.5→2.0→3.5MPa, to match the sludge compression characteristics and improve energy utilization.

[0055] (2) Energy recovery and safety design:

[0056] Integrated residual pressure recovery system: The residual pressure after detonation drives the mechanical dehydration module, such as the membrane filter press, to achieve the "impact-filtration" energy closed loop;

[0057] Explosion-proof chamber design: It adopts a split pressure-resistant chamber, including a main chamber + a buffer chamber, and the pressure reducing valve 19 is linked through the pressure sensor 12 to ensure safe operation.

[0058] (3) Multi-field coupling enhancement mechanism:

[0059] The pressure field, i.e. the detonation shock wave, works in coordination with the temperature field: the shock wave generates local high temperatures, instantaneously reaching 60-80°C, which promotes water evaporation and reduces sludge viscosity.

[0060] 2. Device structure design

[0061] (1) Detonation main reaction chamber

[0062] Material: The inner layer is S31603 duplex stainless steel, with a yield strength of ≥550MPa, and an external annular reinforcement rib with a spacing of 50mm and a height of 20mm.

[0063] Core components: High-pressure gas storage tank 21, CO2 / N2, pressure 5MPa, built-in vortex refrigeration device to maintain the gas temperature between -10℃ and 5℃; pulse solenoid valve 20, response time ≤5ms, piezoelectric ceramic driver control;

[0064] Porous impact plate 3: conical micropores, inlet 0.5mm / outlet 0.1mm, pore density 200 pores / cm 2 , laser micromachining forming.

[0065] The porous impact plate is an annular structure, wherein a hole in the middle is connected to the high-pressure gas pipeline, and the holes around the annulus are high-pressure gas release ports.

[0066] (2) Energy recovery system

[0067] Residual pressure converter 10: Hydraulic cylinder and accumulator are linked together, output pressure 0-12MPa;

[0068] Heat recovery pipe 9: 316L stainless steel spiral tube, total heat transfer coefficient 120W / (m 2 ·K).

[0069] (3) Intelligent control system

[0070] The PLC presets a three-stage program: low-pressure pre-cell breaking → medium-pressure cell crushing → high-pressure water release, and adjusts the pulse frequency and pressure gradient in real time.

[0071] Steps:

[0072] Sludge pretreatment: Pump sludge with a moisture content of 95%-99% into the spherical detonation chamber 1, let it stand for 5-20 minutes, drain the supernatant, and then fill it up again;

[0073] Multi-pulse shock:

[0074] The first stage: 0.5MPa impact × 5 times, 2s interval, destroying the outer EPS layer;

[0075] The second stage: 2.0 MPa impact × 3 times, 5 seconds interval, to break the microbial cells;

[0076] The third stage: 3.5 MPa impact × 1 time, releasing bound water;

[0077] Energy recovery and dehydration: The filter press 11 is driven by the residual pressure at a pressure of 0-12 MPa to obtain a mud cake with a moisture content of ≤55%.

[0078] Example 1: Municipal Sludge Treatment

[0079] Raw material: concentrated sludge from a sewage treatment plant, moisture content 97.3%, CST = 120s;

[0080] Operating parameters:

[0081] 0.5MPa×5 times, 2s interval, →2.0MPa×3 times, 5s interval, →3.5MPa×1 time;

[0082] Effect:

[0083] Mud cake moisture content 53.2%, CST = 28s;

[0084] Energy consumption is 1.8kWh / ton, traditional filter press consumes 4.5kWh, and residual pressure recovery contributes 0.6kWh;

[0085] The sludge calorific value retention rate is 95.4%, the original sludge is 13.1MJ / kg → 12.5MJ / kg after treatment.

[0086] Comparative experimental results:

[0087] Control group 1: only a single impact of 3.5 MPa was used, and the moisture content of the mud cake was 72.4%;

[0088] Control group 2: Traditional Fenton method (Fe 2+ 0.1mol / L, H2O20.3mol / L), the moisture content of the mud cake is 61.5% but the calorific value loss is 28%

[0089] Example 2: Oily sludge treatment

[0090] Raw materials: petrochemical oily sludge, water content 92.5%, oil content 15%;

[0091] Operating parameters: 0.5MPa×6 times→2.5MPa×4 times→4.0MPa×1 time;

[0092] Effect:

[0093] The moisture content of the mud cake is 48.7%, and the oil content is reduced to 3.2%; the oil recovery rate is >85%.

[0094] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0095] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A method for efficient sludge dehydration and conditioning based on multi-pulse detonation shock waves, characterized in that: The method includes sludge pretreatment, multi-pulse detonation shock and energy recovery dehydration; wherein, the step pressure in the multi-pulse detonation shock is 0.5-4.0MPa and the pulse frequency is 1-10Hz.

2. The method for efficient sludge dehydration and conditioning based on multi-pulse detonation shock waves according to claim 1, characterized in that: The multi-pulse detonation shock includes three stages, among which the first stage: 0.5MPa shock × (3~6) times, with an interval of 2s, to destroy the outer EPS; the second stage: 2.0MPa shock × (3~5) times, with an interval of 5s, to break the microbial cells; the third stage: 3.5~4MPa shock × 1 time, to release bound water.

3. The method for efficient sludge dehydration and conditioning based on multi-pulse detonation shock waves according to claim 1, characterized in that: Energy recovery dehydration: Use residual pressure to drive the filter press, with a pressure of 0-12MPa, to obtain a mud cake with a moisture content of ≤55%, and use the residual heat to preheat the sludge to 40-50℃.

4. The method for efficient sludge dehydration and conditioning based on multi-pulse detonation shock waves according to claim 1, characterized in that: Sludge pretreatment: Pump sludge with a moisture content of 95% to 99% into the spherical detonation chamber, let it stand for 5-20 minutes, drain the supernatant, and then fill it up again.

5. A device for realizing the method for efficiently dehydrating and conditioning sludge based on multi-pulse detonation shock waves according to any one of claims 1 to 4, characterized in that: It includes a pulse detonation main reaction chamber, an energy recovery system and an intelligent control system; Among them, the pulse detonation main reaction chamber includes a high-pressure gas storage tank, a pulse solenoid valve and a porous impact plate, wherein the porous impact plate is arranged in the spherical detonation chamber, the pulse solenoid valve is arranged on the pipeline leading from the high-pressure gas storage tank to the spherical detonation chamber, and the outlet end of the pipeline is provided with a porous impact plate; The energy recovery system includes a residual pressure converter and a heat recovery pipe, wherein the residual pressure converter pressurizes the mud cake and the heat recovery pipe is used for heating the sludge; The intelligent control system regulates the pulse frequency and pressure gradient through PLC.

6. The device according to claim 5, characterized in that The energy recovery system is connected to the spherical detonation chamber through a pipeline. A heat recovery pipe is provided on one side of the pipeline, and a residual pressure converter and a residual pressure driven filter press are provided at the output end of the pipeline. The heat recovery pipe is a 316L stainless steel spiral pipe with a heat transfer coefficient of ≥120W / (m 2 ·K).

7. The device according to claim 5, characterized in that The porous impact plate is uniformly distributed with conical micropores, and the inlet diameter D1 and outlet diameter D2 of the conical micropores satisfy D1 / D2=3-5.

8. The device according to claim 5, characterized in that The high-pressure gas storage tank is equipped with a vortex refrigeration device to maintain the gas temperature at -10°C to 5°C.

9. The device according to claim 5, characterized in that The outermost side of the spherical detonation chamber is the detonation cavity wall, and the outer wall of the device is arranged outside the detonation cavity wall. Shock-absorbing and sound-absorbing filling materials are filled between the detonation cavity wall and the outer wall of the device; the outer wall of the device is arranged on a shock-absorbing bracket, and a lifting ring is arranged on the outer wall of the device.

10. The device according to claim 5, characterized in that The spherical detonation chamber is also connected to a mud inlet pipe and a sludge discharge pipe, wherein the mud inlet pipe is provided with a mud inlet control valve and a flexible shock-absorbing valve, and the sludge discharge pipe is provided with a mud discharge valve and a flexible shock-absorbing valve; the liquid level and pressure in the spherical detonation chamber are monitored by a liquid level sensor and a pressure sensor.

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