CN100577250C - Oil-water permanent magnetic separation method and device - Google Patents

Abstract

The invention relates to a method and device for permanent magnetic separation of oil and water, comprising a dosing device (8) for adding a magnetizing agent to oily sewage to be treated; a pipeline mixer (9) for mixing the magnetizing agent with the The oily sewage is mixed to magnetize the oily multi-surface material in the oily sewage to be treated; and the oil-water permanent magnetic separator (10) is used to magnetically separate the magnetized oily multi-surface material in the oily sewage to be treated. First add magnetizer to magnetize the oil-absorbing multi-surface material, and then use permanent magnet to absorb the magnetized oil-containing multi-surface material to achieve the purpose of high-precision oil removal and oil-solid matter. The beneficial effects of the present invention are as follows: 1. High processing precision; 2. Greatly improved processing efficiency, greatly reduced land occupation and volume of the processing unit, and is suitable for processing large amounts of water. 3. Oil-solid suspended matter can be directly separated without filtration, and any emulsified oil, including chemical emulsified oil containing surfactants, can be directly separated without any demulsification measures.

Description

Oil-water permanent magnetic separation method and device

technical field

The invention relates to sewage treatment technology, in particular to a method and a device for treating oily sewage.

Background technique

In the prior art, there are four principles of oil-water separation: gravity method, adsorption method, membrane separation method, and coarse-grained method.

The first gravity method is based on the Stock's principle for oil-water separation. That is to use the different specific gravity of oil and water, and use some technical means to make tiny oil stains grow up, float and separate. Commonly used equipment includes: gravity grease trap, inclined plate grease trap, air flotation, etc. This method cannot separate the emulsified oil, the separation effect and efficiency are poor, and the separation accuracy is generally around 30mg/l. However, due to the simplicity of this method, it is currently the main means of oil-water separation and is used in occasions where the separation accuracy is not high.

The second adsorption method is based on the principle of adsorption for oil-water separation. That is, the oil is adsorbed on the surface of the material through some kind of adsorption material such as fiber, activated carbon and other materials with large specific surface area, so that the oil is released from the water. Commonly used equipment includes: activated carbon adsorption column, paper, oil-absorbing felt, etc. This method loses the adsorption function because the material will be adsorbed and saturated quickly. If you continue to use it, you need to do desorption treatment, but the desorption treatment process is complicated, the cost is high, the treatment is difficult, the practical value is not high, and the industrial production application is less, and it is generally used for small water treatment.

The third membrane separation method is to use the membrane screening principle to intercept and separate larger oil molecules. Commonly used equipment is ultrafiltration membrane equipment. This method has high processing precision and is a rapidly developing means of oil-water separation. But there are many problems: first, the ultrafiltration anti-fouling membrane technology is not yet mature, and most of the products are imported, with short life and high price; second, it consumes a lot of energy; third, and the most important problem is that The water production rate of the filter membrane is 80-90%, that is, ^{80-90m3 of} clear water and 10-20m3 ^of concentrated oily water can be produced by treating 100m3 of oily water per day. For small water treatment, 10-20% of concentrated water can be mixed with It is burned in coal, but it cannot be processed for a large amount of water, thus limiting the practical application range of this method.

The fourth coarse-grained method is to use a coarse-grained material to cause oil and water to differentiate and aggregate due to different wetting angles when they contact the surface of the material, so that tiny oil droplets gather and grow up on the surface of the material and then detach. The substance floats to the surface. Using this method is generally the same as using a sand filter, using coarse-grained materials as a filter layer and operating in a reverse flow mode. Coagulation of oil droplets includes two ways: impact condensation and wetting condensation. Collision condensation, for example, uses external energy such as heating and ultrasonic waves to increase the kinetic energy of oil droplets, causing them to collide with each other and combine to grow and float. Wetting and condensation means that oil is easy to wet on the surface of a certain material and its surface wetting angle is much larger than that of water on the surface, so that fine oil droplets wet, aggregate, and grow up to With a certain size, the buoyancy force overcomes the wetting and adhesion of oil to the surface of the material and floats away from the surface of the material. Coarse granulation commonly used materials are: walnut shells, anthracite, certain ores, certain metal wires and chemical fibers. Use these materials as coarse-grained materials to make various filters and coagulators. Coarse-graining method is a very practical and promising method at present. For example, the applicant's CN1727030 patent application for "two-way flow surface polymerized oil-water separation structure and manufacturing method", because of the use of different structural designs and the use of a special surface polymer material, the oil-water separation accuracy is high, and the treatment accuracy is oily. It can reach 5mg/L or lower (0.5mg/L), and can directly separate some chemically emulsified oils containing surfactants, such as some anionic surfactants. However, the coarse-grained oil-water separator still has the following main problems in its application:

1. In the process of separating oil and water by the coarse graining method, if the water contains some suspended matter, it will block the oil-water separation material. Although backwashing has a certain effect, the life of the material will still be greatly reduced.

2. In order to improve the service life of the oil-water separation material, it is generally necessary to pre-filter the oily sewage to remove suspended matter, and the filtration of oily sewage itself is a difficult problem. Although another product oily sewage filter developed by the applicant can be used, the investment will increase greatly, which is uneconomical when the amount of treated water is small.

3. When containing trace oil-solid suspended matter or oil-solid colloidal suspended matter, it is often difficult to filter and process, and the cost is high.

4. The chemically emulsified oil containing all surfactants cannot be directly separated.

SUMMARY OF THE INVENTION The technical problem to be solved by the present invention is to avoid the shortcomings of the above-mentioned prior art and to propose a method that can ensure high oil-water separation accuracy, very low oil content in the effluent, and a wide range of applications. Oil-solid suspended matter can be treated without filtration, The invention relates to an oil-water permanent magnetic separation method and device which can directly separate chemical emulsified oil containing surfactant without chemical-mechanical demulsification.

The present invention solves described technical problem and can realize by adopting following technical scheme:

Design and use a kind of oil-water permanent magnetic separation method, including the following steps

① Adjust the pH value of the oily sewage to be treated to 11-13;

② Adding a magnetizer into the oily sewage, mixing the magnetizer with the oily sewage evenly, to magnetize the oily multi-surface material in the oily sewage;

③ passing the oily sewage into the magnetic separation network of the permanent magnetic separator, the permanent magnetic separator comprises a cylinder and a magnetic separation network in the cylinder, and the outer wall of the magnetic separation network is evenly distributed with permanent magnets;

④ The magnetized oily multi-surface material in the oily sewage is adsorbed by the permanent magnet on the outer surface of the magnetic separation net, and the water after magnetic separation flows out of the permanent magnetic separator;

⑤ The oily sludge adsorbed on the inner surface of the magnetic separation net is sucked into the rotatable sludge suction pipe by means of a magnetic pump and the oily sludge is discharged out of the permanent magnetic separator.

Design and use an oil-water permanent magnetic separator, including a cylinder body, a water inlet, a water outlet and a magnetic separation net. The cylinder body also includes an upper chamber and a lower chamber, and the upper chamber is completely sealed and isolated from the lower chamber ; The magnetic separation net is located in the lower chamber, and permanent magnets are evenly distributed on its outer wall. The water inlet and water outlet are arranged on the lower chamber, and the upper chamber is provided with a sewage outlet; the oily sewage flows into the magnetic separation net of the lower chamber from the water inlet, and the water after magnetic separation flows out through the water outlet , the oily sludge adsorbed on the inner wall of the magnetic separation net is sucked into the upper chamber by the magnetic pump and discharged out of the cylinder through the sewage outlet.

Design and use a separation system using the above-mentioned oil-water permanent magnetic separator, including a dosing device for adding a magnetizing agent to the oily sewage to be treated; a pipeline mixer for mixing the magnetizing agent with the oily sewage mixing to magnetize the oily multi-surface material in the oily sewage to be treated; the oil-water permanent magnetic separator is used to magnetically separate the magnetized oily multi-surface material in the oily sewage to be treated.

Compared with prior art, technical effect of the present invention is:

1. It can treat influent water containing 4000mg/l of dirty oil (oil-solid matter) into effluent with oil content≤5mg/l and suspended matter SS≤10mg/l.

2. The treatment efficiency is greatly improved. The surface water flow rate of this product can reach 100m/h, and the area and volume of the treatment unit are greatly reduced, which is suitable for the treatment of large water volumes.

3. The water effluent effect can directly separate the oil-solid suspended matter without filtering, and can directly separate any emulsified oil, including chemical emulsified oil containing surfactants, without any demulsification measures, which can be completed in one device. Solid-liquid" and "oil-water" separation.

Description of drawings

Fig. 1 is the schematic diagram of the oil-water permanent magnetic separation system of the present invention;

Fig. 2 is the structural representation of oil-water permanent magnetic separator of the present invention;

Fig. 3 is a cross-sectional view along line A-A of Fig. 2 .

Detailed ways

Below in conjunction with the best embodiment shown in the accompanying drawings, it will be further described in detail.

As shown in Figures 1 to 3, the oil-water permanent magnetic separation method of the present invention comprises the following steps:

① Adjust the PH value of the oily sewage to be treated to 11-13, and the optimal value is 12. If it cannot be satisfied when entering the water, an automatic alkali adding device can be added, and the pipeline mixer 9 can be used to mix evenly, and the pH can be controlled by an online pH controller value;

2. Utilize the automatic dosing device 8 to add a magnetizing agent into the oily sewage, and mix the magnetizing agent with the oily sewage evenly by means of the pipeline mixer 9, so as to magnetize the oily multi-surface material in the oily sewage; , firstly add paramagnetic porous adsorption material with large specific surface area, such as ferric iron, ferrous iron, aluminum salt, to fully react to make oil-solid matter adsorb on the paramagnetic porous adsorption material, and then add Fine powdered ferromagnetic materials, such as low carbon steel, iron filings, etc., make it closely combined with the adsorption material; the automatic dosing device includes polyethylene PE dosing boxes, agitators and dosing metering pumps that are common on the market ;

③ Pass the oily sewage from the side into the magnetic separation network of the permanent magnetic separator, and form a rotating water flow in the magnetic separation network to ensure that the magnetized oily multi-surface material can be completely absorbed by the permanent magnet; the permanent magnetic separation The device includes a cylinder body 1 and a magnetic separation net 4 inside the cylinder body, permanent magnets 5 are evenly distributed on the outer wall of the magnetic separation net 4, so that a magnetic field is generated inside the magnetic separation net 4;

④ The magnetized oily multi-surface material in the oily sewage is adsorbed by the permanent magnet on the outer wall of the magnetic separation net, and the water after magnetic separation flows out of the permanent magnetic separator;

⑤ The oily sludge adsorbed on the inner surface of the magnetic separation net is sucked into the rotatable sludge suction pipe 6 by means of a magnetic pump and the oily sludge is discharged out of the permanent magnetic separator.

As shown in Figure 2, the oil-water permanent magnetic separator of the present invention includes a cylinder body 1, a water inlet 2, a water outlet 3 and a magnetic separation net 4, and the cylinder body 1 includes an upper chamber 11 and a lower chamber 12. The upper chamber 11 is completely sealed and isolated from the lower chamber 12; the magnetic separation net 4 is located in the lower chamber 12, and permanent magnets 5 are evenly distributed on the outer wall thereof. The oil-water permanent magnetic separator also includes a sludge suction pipe 6 that is driven by a motor and rotates along the inner wall of the magnetic separation net 4. The rotating speed of the sludge suction pipe 6 is 1 to 2 rpm, and fine holes are distributed on its peripheral wall. The sludge suction pipe 6 passes through the partition between the upper chamber 11 and the lower chamber 12 , and its lower section 62 is located in the magnetic separation net 4 of the lower chamber 12 and is close to the inner wall of the magnetic separation net 4 . The water inlet 2 is arranged on the upper side wall of the lower chamber 12 , and the water outlet 3 is arranged on the lower side wall of the lower chamber 12 . The sewage outlet 7 is arranged on the side wall of the upper chamber 11 . The oily sewage flows into the magnetic separation network 4 of the lower chamber 12 from the water inlet 2, the water after magnetic separation flows out through the water outlet 3, and the oily sludge adsorbed on the inner wall of the magnetic separation network 4 is constantly working by means of a magnetic pump. Negative pressure is generated on the upper chamber 11 , sucked into the upper chamber 11 through the sludge suction pipe 6 and discharged out of the cylinder body 1 through the sewage outlet 7 .

As shown in Figure 1, the separation system using the oil-water permanent magnetic separator includes a dosing device 8 for adding a magnetizer to the oily sewage to be treated; a pipeline mixer 9 for mixing the magnetizer with the The oily sewage is mixed to magnetize the oily multi-surface material in the oily sewage to be treated; and the oil-water permanent magnetic separator 10 is used to magnetically separate the magnetized oily multi-surface material in the oily sewage to be treated.

Claims (9)

1. a permanent magnetism filtering and separating method for oil-water is characterized in that: may further comprise the steps

1. the pH value with pending oil-polluted water is adjusted to 11～13;

2. adding magnetization agent in described oil-polluted water should be magnetized agent and described oil-polluted water mixes, and made the oil-containing multilist face material magnetization in the oil-polluted water;

3. described oil-polluted water is fed in the magnetic separate mesh of permanent magnetism separator, this permanent magnetism separator comprises the magnetic separate mesh in cylindrical shell and the cylindrical shell, and this magnetic separate mesh outer wall is evenly distributed with permanent magnet;

4. the oil-containing multilist face material that has been magnetized in the described oil-polluted water is by the absorption of the permanent magnet of magnetic separate mesh outer surface, and the water after magnetic separates flows out described permanent magnetism separator;

5. the oily sludge that will be adsorbed on described magnetic separate mesh inner surface by magnetic drive pump sucks rotatable mud suction pipe and described oily sludge is discharged described permanent magnetism separator.

2. permanent magnetism filtering and separating method for oil-water as claimed in claim 1, it is characterized in that: step is 2. middle to add when magnetizing agent, at first in profit, add the very big paramagnetism porous adsorbing material of specific area, fully reaction is adsorbed on this paramagnetism porous adsorbing material oil-solids, and then the ferrimagnet of adding fine-powdered, itself and sorbing material are combined closely.

3. permanent magnetism filtering and separating method for oil-water as claimed in claim 1 is characterized in that: described oil-polluted water enters in the magnetic separate mesh of permanent magnetism separator from side direction, forms rotary water current in the magnetic separate mesh.

4. permanent magnetism filtering and separating method for oil-water as claimed in claim 1 is characterized in that: described pH value is adjusted to 12.

5. a profit permanent magnetism separator comprises cylindrical shell (1), water inlet (2), delivery port (3) and magnetic separate mesh (4), it is characterized in that:

Described cylindrical shell (1) comprises upper chamber (11) and lower chambers (12) again, this upper chamber (11) and the complete seal isolation of lower chambers (12); Described magnetic separate mesh (4) is positioned at described lower chambers (12), and its outer wall is evenly distributed with permanent magnet (5);

Described water inlet (2) and delivery port (3) are arranged on the lower chambers (12), and upper chamber (11) is provided with sewage draining exit (7); Described oil-polluted water flows in the magnetic separate mesh (4) of described lower chambers (12) from water inlet (2), water after magnetic separates flows out through delivery port (3), and the oily sludge that is adsorbed on magnetic separate mesh (4) inwall is inhaled in the described upper chamber (11) by magnetic drive pump and also is discharged from outside the described cylindrical shell (1) by sewage draining exit (7).

6. profit permanent magnetism separator as claimed in claim 5, it is characterized in that: also comprise by electric motor driven mud suction pipe (6) along the rotation of described magnetic separate mesh (4) inwall, be distributed with pore on the perisporium of this mud suction pipe (6), this mud suction pipe (6) passes through the dividing plate between described upper chamber (11) and the lower chambers (12), described mud suction pipe (6) hypomere (62) is positioned at the magnetic separate mesh (4) of lower chambers (12), and the inwall of adjacent this magnetic separate mesh (4); The oily sludge that is adsorbed on magnetic separate mesh (4) inwall is inhaled in the described upper chamber (11) by described mud suction pipe (6) and also is discharged from outside the described cylindrical shell (1) by sewage draining exit (7).

7. profit permanent magnetism separator as claimed in claim 5 is characterized in that: described water inlet (2) is arranged on the upper side wall of described lower chambers (12), and delivery port is arranged on the lower wall of lower chambers (12).

8. profit permanent magnetism separator as claimed in claim 5 is characterized in that: described sewage draining exit (7) is arranged on the sidewall of upper chamber (11).

9. piece-rate system of using profit permanent magnetism separator as claimed in claim 5 is characterized in that: include:

Chemicals dosing plant (8) is used for adding the magnetization agent to pending oil-polluted water;

Pipe-line mixer (9) is used for described magnetization agent is mixed with described oil-polluted water, makes the oil-containing multilist flooring magnetization in the pending oil-polluted water;

With described profit permanent magnetism separator (10), the oil-containing multilist flooring magnetic that is used for pending oil-polluted water has been magnetized separates.

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