Ship bilge oily water treatment device based on high-speed centrifugal separation and membrane filtration method

Abstract

The invention relates to a ship bilge oily water treatment device based on a high-speed centrifugal separation and membrane filtration method, which is characterized in that a buffer heating cabinet is connected with an oily water collecting cabin and is used for receiving bilge oily water and heating the oily water through a heater; the high-speed centrifugal separation module is connected with a buffer heating cabinet, an oil collecting cabinet and a slag discharging cabinet, and a rotating wheel is driven by a variable frequency motor to rotate at a high speed to realize three-phase separation of oil, water and silt; the standard-reaching water outlet and the standard-exceeding valve are connected through the first-stage electromagnetic valve; the membrane filtration module is connected with the high-speed centrifugal separation module through a secondary electromagnetic valve, the suction pump is arranged at the rear end of the buffer heating cabinet, and oily water is sequentially pumped into the high-speed centrifugal separation module and the membrane filtration module through vacuum suction; the electric control box is used for automatically controlling the device to operate, adjusting the rotating speed of the variable frequency motor according to the oil concentration of the effluent and controlling the opening and closing of the primary electromagnetic valve, the standard exceeding valve and the secondary electromagnetic valve. Oily water passes through the high-speed centrifugal separation module, so that the oil-containing particle size of effluent is not greater than 10 microns.

Description

Technical Field

[0001] The present invention relates to the field of ship environmental pollution control, and specifically to a bilge oily sewage treatment device based on high-speed centrifugal separation and ultrafiltration membrane filtration, which is used to treat bilge sewage containing light diesel, heavy oil and emulsified oil to ensure that the oil content of the discharged water is ≤5ppm. Background Art

[0002] The main treatment processes for oily wastewater from bilges of similar ships at home and abroad include: 1) gravity separation + adsorption filtration (such as CN101654150A); 2) gravity separation + coalescence separation + adsorption filtration (such as CN101343095A); 3) gravity separation + coalescence separation + membrane separation; 4) centrifugal separation + dosing and demulsification.

[0003] Currently, most front-end treatment in domestic oily wastewater treatment plants relies on gravity separation. This method is relatively mature, but the required residence time is 10 to 30 minutes, resulting in a large footprint for gravity separation components. Furthermore, gravity separation generally isolates oil droplets larger than 50 μm in diameter, making it particularly difficult to separate solid sediment particles, placing a significant burden on subsequent treatment modules.

[0004] Some foreign oily wastewater treatment devices use high-speed centrifugation methods. This method does not require long-term residence, but the components vibrate and make a lot of noise. It is difficult to meet the emission index requirement of ≤5ppm by relying solely on this method.

[0005] Based on the above analysis of the long residence time of gravity separation and the single high-speed centrifugal separation emission index problems, the present invention proposes a ship bilge oily wastewater treatment device based on high-speed centrifugal separation and membrane filtration methods. It solves the above problems by replacing gravity separation with high-speed centrifugal separation, combined with frequency conversion control, sound insulation and vibration isolation, and pulse membrane backwashing. Summary of the Invention

[0006] The present invention proposes a ship bilge oily wastewater treatment device based on high-speed centrifugal separation and membrane filtration method.

[0007] 1) Use high-speed centrifugal separation and membrane filtration methods to ensure that the oil content of the treated discharge water meets the index requirement of ≤5ppm;

[0008] 2) High-speed centrifugal separation module achieves low vibration and noise operation;

[0009] 3) Remove sediment and solid particles through high-speed centrifugal separation, thereby increasing the service life of the ultrafiltration membrane;

[0010] 4) High-speed centrifugal separation module is used to replace gravity separation to reduce the footprint of the device.

[0011] To achieve the above-mentioned purpose, the technical solution of the present invention is: a ship bilge oily wastewater treatment device based on high-speed centrifugal separation and membrane filtration method, comprising a buffer heating cabinet, a high-speed centrifugal separation module, a membrane filtration module, a suction pump, and an electrical control box. The buffer heating cabinet is connected to the oily wastewater collection tank, which is used to receive the bilge oily wastewater and heat the oily wastewater through a heater; the high-speed centrifugal separation module is connected to the buffer heating cabinet, the oil collecting cabinet and the slag discharge cabinet, and drives the impeller to rotate at high speed through a variable frequency motor to achieve three-phase separation of oil, water and sediment; and is connected to the standard drain outlet and the excess valve through a first-level solenoid valve; the membrane filtration module is connected to the high-speed centrifugal separation module through a second-level solenoid valve, which is used to deeply filter the effluent after high-speed centrifugal separation; the suction pump is arranged at the rear end of the buffer heating cabinet, and pumps the oily wastewater into the high-speed centrifugal separation module and the filter membrane module in sequence through vacuum suction; the electrical control box is used to automatically control the operation of the device, adjust the speed of the variable frequency motor according to the oil concentration of the effluent, and control the switching of the first-level solenoid valve, the excess valve and the second-level solenoid valve.

[0012] Furthermore, a sinusoidal stainless steel inclined plate is provided on the surface of the impeller of the high-speed centrifugal separation module, an oil floating hole is provided on the inclined plate, the inclined plate has an inclination angle of 30°-60°, and the inclined plate spacing is 5-15 mm.

[0013] 3. The device according to claim 1 is characterized in that: the shell of the high-speed centrifugal separation module is embedded with sound-absorbing cotton, and the outside of the shell is combined with a frame vibration isolator and a vibration absorbing block to achieve vibration reduction.

[0014] Furthermore, the high-speed centrifugal separation module is equipped with a self-cleaning system, including a cleaning liquid injection pipeline and a rotating nozzle, to regularly clean the impeller and the inclined plate.

[0015] Furthermore, the membrane filtration module uses an ultrafiltration membrane with a pore size of 0.01-0.1 μm and is equipped with a pulse backwashing device to return the backwashed dirty water to the bottom of the cabin.

[0016] Furthermore, the variable frequency motor dynamically adjusts the rotation speed according to the outlet water oil concentration signal fed back by the electric control box, so that the centrifugal acceleration range is 3000g-6000g.

[0017] Furthermore, a temperature sensor is provided in the buffer heating cabinet, and the heating temperature is controlled at 40°C-60°C, and the viscosity of the oily wastewater is reduced to 30%-50% of the original value.

[0018] Furthermore, the electric control box integrates a fault diagnosis module to monitor the motor current, membrane pressure difference and valve status in real time, and automatically switches to the backup system when an alarm is triggered.

[0019] Furthermore, the suction pump is a corrosion-resistant screw pump with a flow rate adjustment range of 0.5-10m 3 / h, and the vacuum degree is maintained at -0.05MPa to -0.08MPa.

[0020] Furthermore, the device also includes a pre-filter, which is arranged at the front end of the suction pump, has a filtration accuracy of 100μm, and is made of 316L stainless steel.

[0021] The beneficial effects of the present invention are:

[0022] 1) The oily wastewater is separated by high-speed centrifugation to make the oily particle size of the effluent ≯10um.

[0023] 2) Through the variable frequency motor of the high-speed centrifugal separation module, the centrifugal separation acceleration of oily wastewater can be achieved at 3000g~6000g.

[0024] 3) Through the noise reduction, vibration isolation and vibration absorption technology of the high-speed centrifugal separation module, the noise level of the device operation is reduced to ≯75dB.

[0025] 4) The oil particle size of the discharged water filtered by ultrafiltration membrane reaches nanometer level, and the final oil content of the discharged water meets the index requirement of ≤5ppm.

[0026] 5) Through the pulse backwash technology of the filter membrane and the automatic switching of the operation mode of the device, the service life of the filter membrane is ensured to be about 5 years. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the system of the bilge oily sewage treatment device of the present invention;

[0028] Figure 2 It is a schematic diagram of the high-speed centrifugal separation module. DETAILED DESCRIPTION

[0029] The present invention proposes a ship bilge oily wastewater treatment device based on high-speed centrifugal separation and membrane filtration methods. In order to make the advantages and technical solutions of the present invention clearer and more specific, the present invention is described in detail below with reference to specific embodiments.

[0030] like Figure 1 As shown, a ship bilge oily wastewater treatment device 20 based on high-speed centrifugal separation and membrane filtration method of the present invention mainly includes a buffer heating cabinet 1, a heater 2, an electric control box 3, a high-speed centrifugal separation module 4, a first-level solenoid valve 5, an excess valve 6, a membrane filtration module 7, a second-level solenoid valve 8, and a suction pump 9.

[0031] like Figure 2 As shown, the high-speed centrifugal separation module 4 mainly includes an inclined plate 10, a variable frequency motor 11, a rotor 12, a shell sound-absorbing cotton 13, a vibration-absorbing block 14, and a frame vibration isolator 15.

[0032] The buffer heating cabinet 1 is connected to the oily wastewater collection tank 17, and is used to receive the oily wastewater from the bilge and heat the oily wastewater through the heater 2;

[0033] The high-speed centrifugal separation module 4 is connected to the buffer heating cabinet 1, the oil collecting cabinet and the slag discharge cabinet, and drives the runner 12 to rotate at high speed through the frequency conversion motor 11 to achieve three-phase separation of oil, water and sediment; and is connected to the standard drain outlet and the excess valve 6 through the first-level solenoid valve 5;

[0034] The membrane filtration module 7 is connected to the high-speed centrifugal separation module 4 through a secondary solenoid valve 8, and is used to perform deep filtration on the effluent after high-speed centrifugal separation;

[0035] The suction pump 9 is arranged at the rear end of the buffer heating cabinet 1, and pumps the oily wastewater into the high-speed centrifugal separation module 4 and the filter membrane module 7 in sequence through vacuum suction;

[0036] The electric control box 3 is used to automatically control the operation of the device, adjust the speed of the variable frequency motor 11 according to the oil concentration of the outlet water, and control the opening and closing of the first-level solenoid valve 5, the excess valve 6 and the second-level solenoid valve 8.

[0037] (1) The high-speed centrifugal separation module 4 uses a variable frequency motor, which adjusts the separation speed by judging the oil concentration at the water outlet to achieve economic operation of the device.

[0038] (2) A high-speed centrifugal separation module 4 is used to quickly separate the three phases of water, oil and sediment, and the particle size of the oil droplets after separation is ≯10um.

[0039] (3) The high-speed centrifugal separation module 4 is equipped with a sinusoidal stainless steel inclined plate to enhance the probability of oil droplet collision. At the same time, the inclined plate is provided with an oil floating hole to facilitate the rapid floating of oil droplets.

[0040] (4) The high-speed centrifugal separation module 4 is provided with a self-cleaning function, which cleans the impeller and the inclined plate by adding cleaning fluid.

[0041] (5) Through the treatment mode of high-speed centrifugal separation as the main method and membrane filtration as the auxiliary method, it can achieve the treatment standard under extreme water quality conditions and reduce the frequency of membrane filtration.

[0042] (6) Noise-absorbing cotton is embedded in the wall of the high-speed centrifugal separation cylinder to block the noise of fluid collision and mechanical movement in the cylinder. At the same time, the centrifugal separation module adopts a combination of ground vibration isolation and frame vibration absorption to reduce the vibration transmission of the device.

[0043] (7) The membrane filtration module 7 uses an ultrafiltration membrane. When the operating resistance of the membrane filtration module 7 is large, pulse backwashing is automatically started, and the dirty water from the backwashing flows back to the bottom of the cabin.

[0044] (8) The device uses vacuum suction to extract the oily wastewater, and the suction pump 9 is set at the rear end of the buffer heating cabinet 1. The heated oily wastewater is pumped into the high-speed centrifugal separation module 4 and the filter membrane module 7 in sequence.

[0045] During operation, the bilge oily wastewater is vacuumed in by a suction pump and first passes through a pre-filter 16 to remove large impurities. It is then heated in a buffer heating cabinet 1. The heated oily wastewater is then pumped into a high-speed centrifugal separation module 4, where it rapidly separates the water, oil, and sediment phases. The separated oil enters an oil collection tank, and the sludge enters a slag discharge tank. If the wastewater passes inspection, the first-stage solenoid valve 5 opens, allowing the wastewater to be discharged directly overboard. If it fails inspection, the second-stage solenoid valve 8 opens, allowing the wastewater to enter a membrane filtration module 7 for further treatment, ultimately ensuring that the wastewater meets discharge standards.

[0046] The variable frequency motor 11 of the high-speed centrifugal separation module drives the impeller 12 to rotate at high speed, causing the oily wastewater to generate a strong centripetal force. Passing through the inclined plate 10, it accelerates the collision and separation of the oil droplets.

[0047] The electric control box 3 realizes the fully automatic control operation of the device and transmits the operation and fault alarm signals to the monitoring system. It can switch the speed of the variable frequency motor according to the oil concentration of the outlet water.

[0048] Example 1:

[0049] A new type of marine oil wastewater treatment device CYZ (B) -0.5 has been developed. The water flow rate of the device is Q = 0.5m 3 / h.

[0050] The water flow rate of the device is 0.5m 3 / h. After passing through the pre-filter, the oily wastewater enters the buffer heating cabinet 1, where it is heated to 50°C to reduce viscosity. A suction pump 9 pumps the oily wastewater into the high-speed centrifugal module 4. A variable-frequency motor 11 operates at a centrifugal acceleration of 4000g. After separation, the oil content in the wastewater is reduced to 5ppm. If the test passes, the first-stage solenoid valve 5 is activated for direct discharge. If the oil content exceeds the standard, the second-stage solenoid valve 8 is activated, and the wastewater enters the membrane filtration module 7 for treatment until the oil content is ≤3ppm.

[0051] Example 2:

[0052] The inclined plates 10 of the high-speed centrifugal module 4 adopt a sinusoidal waveform design with a spacing of 10mm, an inclination of 45°, and an oil floating hole diameter of 3mm. Tests show that the probability of oil droplet collision is increased by 30% and the separation efficiency reaches 98%.

[0053] Example 3:

[0054] When the operating pressure difference of the ultrafiltration membrane (pore size 0.05 μm) of the membrane filtration module 7 reaches 0.15 MPa, the electric control box 3 triggers pulse backwashing (frequency 2 Hz, duration 10 seconds), and the membrane flux recovers to 95% of the initial value.

[0055] Example 4:

[0056] The electric control box 3 monitors the motor current in real time. When the current fluctuation exceeds ±10%, it determines that the wheel 12 is blocked and automatically injects cleaning fluid for cleaning, which takes 5 minutes to restore the separation efficiency.

[0057] Example 5:

[0058] The pre-filter intercepts metal chips and fibers with a particle size greater than 100 μm, the sediment deposition in the high-speed centrifugal module 4 is reduced by 80%, and the maintenance period of the impeller 12 is extended to 6 months.

[0059] The core innovation of this invention is to replace gravity separation with high-speed centrifugal separation, combined with ultrafiltration membrane depth filtration, and achieve low energy consumption, low noise, and high stability operation through intelligent control.

[0060] (1) High-speed centrifugal separation module: uses a variable frequency motor to drive the rotor, with a centrifugal acceleration of 3000g-6000g, separating oil droplets ≥10μm and sediment;

[0061] (2) Membrane filtration module: Ultrafiltration membrane combined with pulse backwashing to treat nano-sized oil droplets;

[0062] (3) Vibration and noise reduction design: shell silencer cotton, frame vibration isolator and vibration absorbing block are combined to reduce noise;

[0063] (4) Intelligent control system: Dynamically adjust the speed and valve according to water quality to achieve fully automatic operation.

[0064] (5) Technical effect: Treatment efficiency increased by 50%, floor space reduced by 40%; oil content in discharged water ≤5ppm, ultrafiltration membrane life ≥5 years; operating noise ≤75dB, vibration reduced to below ISO 10816-3 standard.

Claims

1. A ship bilge oily wastewater treatment device based on high-speed centrifugal separation and membrane filtration method, characterized by: It includes a buffer heating cabinet, a high-speed centrifugal separation module, a membrane filtration module, a suction pump, and an electrical control box. The buffer heating cabinet is connected to the oily wastewater collection tank, which is used to receive the oily wastewater at the bottom of the bilge and heat the oily wastewater through a heater; the high-speed centrifugal separation module is connected to the buffer heating cabinet, the oil collecting cabinet and the slag discharge cabinet, and drives the impeller to rotate at high speed through a variable frequency motor to achieve three-phase separation of oil, water and sediment; and is connected to the standard drain outlet and the excess valve through a first-level solenoid valve; the membrane filtration module is connected to the high-speed centrifugal separation module through a second-level solenoid valve, which is used to deeply filter the effluent after high-speed centrifugal separation; the suction pump is arranged at the rear end of the buffer heating cabinet, and pumps the oily wastewater into the high-speed centrifugal separation module and the filter membrane module in sequence through vacuum suction; the electrical control box is used to automatically control the operation of the device, adjust the speed of the variable frequency motor according to the oil concentration of the effluent, and control the switching of the first-level solenoid valve, the excess valve and the second-level solenoid valve.

2. The ship bilge oily wastewater treatment device based on high-speed centrifugal separation and membrane filtration method according to claim 1 is characterized by: The surface of the impeller of the high-speed centrifugal separation module is provided with a sinusoidal stainless steel inclined plate, an oil floating hole is provided on the inclined plate, the inclined plate has an inclination angle of 30°-60°, and the inclined plate spacing is 5-15 mm.

3. The ship bilge oily wastewater treatment device based on high-speed centrifugal separation and membrane filtration method according to claim 1 is characterized in that: The shell of the high-speed centrifugal separation module is embedded with sound-absorbing cotton, and the outside of the shell is combined with a frame vibration isolator and a vibration absorbing block to achieve vibration reduction.

4. The ship bilge oily wastewater treatment device based on high-speed centrifugal separation and membrane filtration method according to claim 1 is characterized in that: The high-speed centrifugal separation module is equipped with a self-cleaning system, including a cleaning liquid injection pipeline and a rotating nozzle, to regularly clean the impeller and the inclined plate.

5. The ship bilge oily wastewater treatment device based on high-speed centrifugal separation and membrane filtration method according to claim 1 is characterized in that: The membrane filtration module adopts an ultrafiltration membrane with a pore size of 0.01-0.1 μm and is equipped with a pulse backwashing device to return the backwashed dirty water to the bottom of the cabin.

6. The ship bilge oily wastewater treatment device based on high-speed centrifugal separation and membrane filtration method according to claim 1 is characterized in that: The variable frequency motor dynamically adjusts the rotation speed according to the outlet water oil concentration signal fed back by the electric control box, so that the centrifugal acceleration range is 3000g-6000g.

7. The ship bilge oily wastewater treatment device based on high-speed centrifugal separation and membrane filtration method according to claim 1 is characterized by: The buffer heating cabinet is equipped with a temperature sensor, and the heating temperature is controlled at 40°C-60°C, and the viscosity of the oily wastewater is reduced to 30%-50% of the original value.

8. The ship bilge oily wastewater treatment device based on high-speed centrifugal separation and membrane filtration method according to claim 1 is characterized by: The electric control box integrates a fault diagnosis module to monitor the motor current, membrane pressure difference and valve status in real time, and automatically switches to the backup system when an alarm is triggered.

9. The ship bilge oily wastewater treatment device based on high-speed centrifugal separation and membrane filtration method according to claim 1 is characterized in that: The suction pump is a corrosion-resistant screw pump with a flow adjustment range of 0.5-10m 3 / h, and the vacuum degree is maintained at -0.05MPa to -0.08MPa.

10. The ship bilge oily wastewater treatment device based on high-speed centrifugal separation and membrane filtration method according to any one of claims 1 to 9, characterized in that: The device also includes a pre-filter, which is arranged at the front end of the suction pump, has a filtration accuracy of 100μm, and is made of 316L stainless steel.

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