CN113880380A

CN113880380A - Oily sludge treatment method and device

Info

Publication number: CN113880380A
Application number: CN202111349963.9A
Authority: CN
Inventors: 赵娇; 王银; 王勤; 牟义伟; 张宸铭; 朱益民
Original assignee: Dalian Maritime University
Current assignee: Dalian Maritime University
Priority date: 2021-11-15
Filing date: 2021-11-15
Publication date: 2022-01-04
Anticipated expiration: 2041-11-15
Also published as: CN113880380B

Abstract

The invention provides a method and a device for treating oily sludge. A method for treating oily sludge comprises the following steps: s1: putting the oily sludge, the magnesium minerals and the washing water into a high-speed stirring and cleaning container for mixing and stirring; s2: performing centrifugal dehydration on the sludge obtained in the step S1; s3: adding magnesium minerals and purified water into the sludge obtained in the step S2, and uniformly mixing; s4: and (5) airing and air-drying treatment. The device comprises a pre-stirring system, a high-speed stirring and cleaning device, a centrifugal dehydration device, a repair device and an oil content collection device, wherein the pre-stirring system, the high-speed stirring and cleaning device, the centrifugal dehydration device and the repair device are sequentially connected, and an oil outlet end of the high-speed stirring and cleaning device is communicated with the oil content collection device. The invention overcomes the problem of long flow of oil sludge separation treatment, achieves the effect of quickly separating oil sludge, and efficiently reduces the oil sludge residual oil rate.

Description

Oily sludge treatment method and device

Technical Field

The invention relates to the field of harmless treatment of oily sludge, in particular to a method and a device for treating oily sludge.

Background

Oily solid waste generated in the processes of oil exploitation, transportation, refining and oily sewage treatment is called oily sludge. The oily sludge is an emulsification system formed by mixing water, petroleum hydrocarbons, solid silt and the like, is difficult to degrade and is difficult to bury, and the oily sludge contains toxic substances such as polycyclic aromatic hydrocarbon, benzene and the like, so that the oily sludge has serious harm to the environment and human beings and is brought into a hazardous waste control list (HW 08) by China. At present, the pollution caused by the oily sludge is more and more important to be paid attention to by various countries, and the disposal and treatment of the oily sludge become serious and urgent major environmental management problems.

The prior patent document with publication number CN110776224A discloses a method for treating oily sludge, which comprises the steps of firstly treating the oily sludge by adopting a grinding and cleaning method, and then repairing and treating the oily sludge after grinding and cleaning by adopting a repairing agent, so that the problems of poor treatment effect and large medicament consumption of a single method are solved.

However, the method has a long treatment process, and requires the steps of grinding, cleaning, sieving, centrifugal dehydration, oil-water separation, repair treatment and the like, so that the treatment efficiency is low.

Disclosure of Invention

The invention provides an oil-containing sludge treatment method and device, which are used for overcoming the problem of long flow of oil sludge separation treatment, achieving the effect of quickly separating oil sludge and efficiently reducing the oil sludge residual oil rate.

A method for treating oily sludge comprises the following steps:

s1: taking two parts of magnesium-containing minerals, and calcining the two parts of magnesium-containing minerals at the high temperature of 600-800 ℃ for 2-4h to obtain calcined magnesium-containing minerals;

s2; putting the oily sludge, the calcined first part of magnesium-containing mineral obtained in the step S1 and washing water into a high-speed stirring and cleaning container, mixing and stirring, and washing to obtain oil and sludge;

s3: performing centrifugal dehydration on the sludge obtained in the step S2, and respectively collecting the centrifuged liquid and sludge;

s4: adding the second part of calcined magnesium-containing mineral obtained in the step S1 and purified water into the sludge obtained in the step S3, and uniformly mixing to obtain a mixture;

s5: and (4) airing and air-drying the mixture obtained in the step (S4).

Further, in the step S2, the weight ratio of the addition amount of the first calcined magnesium-containing mineral to the oily sludge is (0.05-0.15): 1.

further, the weight ratio of the addition amount of the washing water to the oily sludge in the step S2 is (6-9): 1.

further, in step S2, the stirring time is 5-10min, and the rotation speed of the stirrer is 4000-7000 r/min.

Further, the stirring time of step S4 is 3-5 min; the rotating speed of the stirrer is 1000-2000 r/min.

Further, in the step S4, the weight ratio of the addition amount of the magnesium-containing mineral after the second part of calcination to the sludge is (0.1-0.3): 1.

further, the weight ratio of the pure water to the sludge in the step S4 is (1-2): 1.

further, step S5, stirring for 2-5 times a day during the airing and air drying process, and treating for 1-3 days.

Further, in step S5, the oil content of the air-dried mixture is 0.8 to 1.5 wt%.

The device comprises a pre-stirring system, a high-speed stirring and cleaning device, a centrifugal dehydration device, a repair device and an oil content collection device, wherein the pre-stirring system, the high-speed stirring and cleaning device, the centrifugal dehydration device and the repair device are sequentially connected, and an oil outlet end of the high-speed stirring and cleaning device is communicated with the oil content collection device.

The subject name of the invention has the beneficial effects that:

1. the combined treatment method of firstly stirring at a high speed and cleaning and then repairing is adopted, so that the problem of long treatment flow of the earlier-stage method is solved, the process is simple, and the operation is simple;

2. the high-speed stirring cleaning device can generate strong shearing force and air flotation effect in the stirring process, achieves hydrodynamic cavitation, and further rapidly achieves the oil sludge separation effect, so that the oil sludge residual oil rate is efficiently reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic view of the overall structure of an oily sludge treatment apparatus according to the present invention;

FIG. 2 is a schematic view of the overall structure of a high-speed stirring cleaning device in the oily sludge treatment device according to the present invention;

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2;

FIG. 4 is a schematic structural view of a stirring rotor in a high-speed stirring and cleaning device in the oily sludge treatment device according to the present invention;

FIG. 5 is a schematic structural view of a sleeve in the high-speed stirring cleaning device in the oily sludge treatment device of the present invention.

In the figure: 1. a pre-agitation system; 11. a pre-agitation tank; 12. a pre-stirring motor; 2. a high-speed stirring cleaning device; 21. a housing; 211. a feed inlet; 212. a discharge port; 213. an air outlet; 22. a stirring rotor; 221. a stirring ring; 222. a stirring blade; 23. a drive motor; 24. a stirring shaft; 25. a sleeve; 251. a through hole; 3. a centrifugal dehydration device; 31. a centrifuge; 4. a prosthetic device; 5. an oil collecting device; 6. an oil guide pipe; 7. a pipeline; 81. a first screw pump; 82. a second screw pump; 9. and (4) a conveyor belt.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to fig. 1 to 5 in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

Referring to fig. 1, the present application provides an oily sludge treatment device, including stirring system 1 in advance, high-speed stirring belt cleaning device 2, centrifugal dehydration device 3, prosthetic devices 4 and oil content collection device 5, stirring system 1 in advance, high-speed stirring belt cleaning device 2, centrifugal dehydration device 3, prosthetic devices 4 connect in order, and centrifugal dehydration device 3 is centrifuge 31.

Referring to fig. 1, wherein, the preliminary mixing system 1 includes a preliminary mixing tank 11 capable of containing oily sludge, a mixing shaft 24 is arranged inside the preliminary mixing tank 11, a preliminary mixing motor 12 capable of driving the mixing shaft 24 to rotate is arranged outside the preliminary mixing tank 11, and the mixing shaft 24 is driven to rotate by the preliminary mixing motor 12, so that the agglomerated sludge inside the preliminary mixing tank 11 can be broken.

Referring to fig. 2 and 3, the high-speed stirring cleaning device 2 includes a housing 21 for containing oily sludge, a stirring rotor 22, and a driving motor 23, wherein the housing 21 is a cylinder with a hollow interior, the inner diameter of the housing 21 is 15cm, and the height of the housing 21 is 20 cm. The upper end of the side wall of the shell 21 is provided with a feed inlet 211, and the lower end of the side wall of the shell 21 is provided with a discharge outlet 212. The upper end of the side wall of the shell 21 is further provided with an air outlet 213, the air outlet 213 and the feed inlet 211 are arranged oppositely, an oil guide pipe 6 is fixedly arranged at the air outlet 213, the oil guide pipe 6 inclines downwards, the oil content collecting device 5 is positioned right below an oil outlet of the oil guide pipe 6, and the generated oil content is condensed into liquid in the oil guide pipe 6 and enters the oil content collecting device 5 along the oil guide pipe 6. The oil collecting device 5 is a vessel having an upper end opened.

Referring to fig. 3 and 4, the stirring shaft 24 is vertically disposed, and a space is reserved between the lower end surface of the stirring shaft 24 and the bottom wall of the shell 21, wherein the space is 1-2 cm. The stirring rotors 22 are plural, and the plural stirring rotors 22 are arranged at equal intervals from top to bottom along the axial direction of the stirring shaft 24. The stirring rotor 22 includes an annular stirring ring 221, four stirring blades 222 are provided between the stirring ring 221 and the stirring shaft 24, and the four stirring blades 222 are circumferentially arrayed along the circumferential direction of the stirring ring 221.

Referring to fig. 3 and 5, a sleeve 25 is sleeved outside the stirring shaft 24, the sleeve 25 is cylindrical with openings at upper and lower ends, the sleeve 25 covers the outside of the stirring rotor 22, and the distance between the inner wall of the sleeve 25 and the stirring rotor 22 is 0.5mm to 1.0mm, and more preferably 1.0 mm. The upper end of the sleeve 25 is fixedly connected with the top wall of the shell 21, and the lower end is a free end. The sleeve 25 is provided with a plurality of through holes 251 along the circumferential direction, and the diameter of the through holes 251 close to the outer surface of the upper-layer stirring rotor 22 is 2 mm; the through-holes 251 near the outer surfaces of the middle and lower stirring blades 222 are vertical holes having a width of 0.5cm and a height of 1.0 cm.

Referring to fig. 1, the repairing device 4 and the high-speed stirring cleaning device 2 have the same structure and are not described in detail.

Referring to fig. 1, pipelines 7 are respectively arranged between the pre-stirring system 1 and the high-speed stirring and cleaning device 2, and between the high-speed stirring and cleaning device 2 and the centrifugal dewatering device 3, a first screw pump 81 and a second screw pump 82 are respectively arranged on the two pipelines 7, the first screw pump 81 is started, and slurry in the pre-stirring system 1 can be pumped into the high-speed stirring and cleaning device 2 through the first pipeline 7; the second screw pump 82 is turned on, and the slurry inside the high-speed agitation and cleaning apparatus 2 is pumped into the centrifugal dehydration apparatus 3 through the second line 7, and the slurry can be centrifugally moved inside the centrifugal dehydration apparatus 3.

Referring to fig. 1, a conveyor belt 9 is arranged between the centrifugal dehydration device 3 and the restoration device 4, the conveyor belt 9 is obliquely arranged, the lower end of the conveyor belt 9 is communicated with the centrifugal dehydration device 3, the upper end of the conveyor belt 9 is communicated with the restoration device 4, and sludge generated after centrifugation can be conveyed into the restoration device 4.

The implementation principle of the embodiment of the application is as follows: firstly, a pre-stirring system 1 is adopted to break up caking oil sludge in oily sludge, the oil sludge is pre-stirred to form slurry, a first screw pump 81 is utilized to transfer the slurry in the pre-stirring system 1 to a high-speed stirring cleaning device 2, a stirring rotor 22 is used for high-speed stirring under the action of a driving motor 23, cavitation occurs simultaneously and generates a large amount of vacuoles, the oily sludge is subjected to hydrodynamic cavitation treatment, and the generated vacuoles carry oil components to move upwards and enter an oil component collecting device 5 through an oil guide pipe 6 for centralized collection and recycling. Mud shifts to centrifugal dehydration device 3 through second screw pump 82 and carries out centrifugal dehydration in, and water recovery cyclic utilization after the centrifugation, mud carry out repairing process in getting into prosthetic devices 4 through conveyer belt 9, and after the stirring, repair mud is followed prosthetic devices 4's discharge gate 212 ejection of compact, dries the processing to the ejection of compact. The oil content of the treated oil sludge is reduced from 14.5% to 0.8%, and the oil sludge meets the current universal industry standard oil-containing sludge comprehensive utilization pollution control standard (DB23/T1413-2010) of oil fields and the emission standard (HJ60T-2011) regulated by the national ministry of environmental protection.

Example 2

The application also provides an oily sludge treatment method, which comprises the following steps:

s1: weighing two parts of magnesium-containing minerals which are magnesite, and calcining the two parts of magnesite at high temperature, wherein the calcining temperature is 650 ℃ and the calcining time is 4 hours to obtain calcined magnesite; the calcined magnesite was then divided into two portions.

S2: weighing oil-containing sludge and washing water of a Daqing oil field with the oil content of about 15 wt%, adding into a pre-stirring system 1, wherein the rotating speed is 5000r/min, and the stirring time is 3min, so as to prepare slurry; then, starting the first screw pump 81, pumping the obtained slurry into the high-speed stirring and cleaning device 2, adding the first calcined magnesite prepared in the step S1 into the high-speed stirring and cleaning device 2, wherein the rotating speed is 6000r/min, and the stirring time is 6min, so as to obtain oil and sludge;

the stirring rotor 22 in the high-speed stirring cleaning device 2 generates strong shearing force in the high-speed rotating process, cavitation occurs and a large amount of cavitation bubbles are generated, and after the mud liquid is subjected to hydrodynamic cavitation treatment in the high-speed stirring cleaning device 2, oil content floats upwards along with the cavitation bubbles and enters the oil content collection device 5 through the oil guide pipe 6;

s3: starting a second screw pump 82, pumping the sludge obtained in the step S2 into a centrifugal dehydration device 3 for centrifugal dehydration treatment for 10min to obtain liquid and sludge, and recycling and reusing the liquid;

s3: starting a conveyor belt 9 to convey the sludge obtained in the step S2 to the interior of the repairing device 4, adding purified water and the second part of calcined magnesite prepared in the step S1 into the repairing device 4, wherein the rotating speed is 1000r/min, and the stirring time is 3min to obtain a mixture;

s4: and (5) discharging the mixture obtained in the step (S3) to the outside of the repairing device 4, and carrying out airing and air-drying treatment at room temperature, wherein the stirring is carried out for 2-5 times every day in the airing and air-drying process, and the treatment is carried out for 1-3 days.

TABLE 1 composition table of each raw material in the examples of the oily sludge treatment method

Example 8: the difference from example 2 is that both magnesium-containing minerals are hydromagnesite.

Example 9: the difference from example 2 is that the first part of the magnesium-containing mineral is magnesite and the second part of the magnesium-containing mineral is hydromagnesite.

Comparative example

Comparative example 1: the difference from example 2 is that the two magnesium-containing minerals were not subjected to high temperature calcination.

Comparative example 2: the difference from example 2 is that the first calcined magnesite charge: the ratio of the oily sludge to the oily sludge is 0.02: 1.

Comparative example 3: the difference from example 2 is that the washing water: the oil-containing sludge is 4: 1.

Comparative example 4: the difference from example 2 is that the second calcined magnesite addition: the ratio of the oily sludge to the oily sludge is 0.05: 1.

Comparative example 5: the difference from example 2 is that a high-speed agitation cleaning apparatus was not used in step S2.

Performance test

In the processing procedures of the above examples 2 to 9 and comparative examples 1 to 5, the oil content of the mixture was measured after 1 day of air-drying and air-drying treatment, and the measurement results are shown in table 2 with reference to national standard "infrared photometry for measuring oil in soil (referred to as" observation manuscript ") and" infrared photometry for measuring oil in water (HJ637-2012) "and animal and vegetable oils.

TABLE 2 test results

Test items	Example 2	Example 3	Example 4	Example 5	Example 6
						Oil content (wt%)	0.8	1.33	0.83	0.81	0.95
Test items	Example 7	Example 8	Example 9
						Oil content (wt%)	0.92	0.91	0.86
Test items	Comparative example 1	Comparative example 2	Comparative example 3	Comparative example 4	Comparative example 5
						Oil content (wt%)	2.79	1.57	1.56	1.79	5.63

By combining examples 2-9 and comparative example 1 and the data in table 2, it can be seen that the oil-containing sludge is repaired by using the magnesium-containing mineral which is not subjected to high-temperature calcination, the oil content of the mixture after airing is higher than 1.5 wt%, and the treatment effect of the oil-containing sludge is poor by using the magnesium-containing mineral which is not subjected to high-temperature calcination; meanwhile, the treatment effect of magnesite after high-temperature calcination is better than that of hydromagnesite, the treatment effects of two magnesium-containing minerals after high-temperature calcination reach that the oil content is lower than 1.5 wt%, and the treatment effects meet the current universal industry standard ' oil field oily sludge comprehensive utilization pollution control standard ' (DB23/T1413-2010) and the emission standard (HJ60T-2011) specified by the national ministry of environmental protection '.

By combining examples 2-9 and comparative example 2, and by combining the data in table 2, it can be seen that when the weight ratio of the magnesium-containing mineral to the oily sludge after the first calcination is 0.12:1, the remediation effect on the oily sludge is best, and the oil content of the oily sludge can be reduced to 0.8 wt%; as the weight ratio of the magnesium-containing mineral to the oily sludge after the first calcination is increased, when the weight ratio of the magnesium-containing mineral to the oily sludge after the first calcination is between 0.15:1 and 0.12:1, the oil content of the oily sludge after the remediation is close to 0.8 wt%; when the weight ratio of the magnesium-containing mineral to the oily sludge after the first calcination is less than 0.05:1, along with the reduction of the weight ratio of the magnesium-containing mineral to the oily sludge after the first calcination, the magnesium-containing mineral after the first calcination does not completely repair the oily sludge, so that the magnesium-containing mineral after the first calcination is wasted, and the repair effect of the oily sludge is reduced.

By combining the examples 2-9, the comparative example 2 and the comparative example 4 and combining the data in the table 2, it can be seen that the influence of the addition of the second calcined magnesite on the remediation of the oily sludge is large, the treatment effect on the oily sludge is gradually enhanced along with the increase of the addition of the second calcined magnesite, and the oil content of the remediated oily sludge is gradually close to 0.8 wt%.

When the washing water is added in a reduced amount and the treatment effect on the oily sludge is gradually weakened, the weight ratio of the washing water to the oily sludge is (6-9): when the amount of the washing water is 1, the influence of the addition amount of the washing water on the repairing effect of the oily sludge is small, and the oil content of the repaired oily sludge is close to 0.8 wt%.

Combining example 2 and comparative example 4, and the data in table 2, it can be seen that the weight ratio of the second calcined magnesite addition to the oily sludge is less than (0.1-0.3): 1, which has a repair effect lower than that in (0.1-0.3): 1, repair effect in the range.

By combining examples 2-9 and comparative examples 1-4, and by combining the data in Table 2, it can be seen that the problem of long treatment flow of the previous method is solved by using a combined treatment method of high-speed stirring cleaning and repairing. The specially designed stirring rotor 22 can generate strong shearing force and air flotation effect to quickly achieve the effect of oil/sludge separation, thereby efficiently reducing the residual oil rate of the oil-containing sludge.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. The method for treating the oily sludge is characterized by comprising the following steps of:

s1: taking two parts of magnesium-containing minerals, and respectively calcining the two parts of magnesium-containing minerals at the high temperature of 600-800 ℃ for 2-4h to obtain calcined magnesium-containing minerals;

s5: and (4) airing and air-drying the mixture obtained in the step (S4).

2. The method of claim 1, wherein the ratio of the amount of the magnesium-containing mineral added after the first calcination to the weight of the oily sludge in step S2 is (0.05-0.15): 1.

3. the method according to claim 1, wherein the weight ratio of the amount of the washing water added to the oily sludge in step S2 is (6-9): 1.

4. the method as claimed in claim 1, wherein the stirring time in step S2 is 5-10min, and the rotation speed of the stirrer is 4000-7000 r/min.

5. The method for treating oily sludge according to claim 1, wherein the stirring time of the step S4 is 3-5 min; the rotating speed of the stirrer is 1000-2000 r/min.

6. The method for treating oily sludge according to claim 1, wherein the weight ratio of the addition amount of the second part of calcined magnesium-containing mineral to the sludge in step S4 is (0.1-0.3): 1.

7. the method for treating oily sludge according to claim 1, wherein the weight ratio of the pure water added in step S4 to the sludge is (1-2): 1.

8. the method for treating oily sludge according to claim 1, wherein in the step S5, stirring is carried out 2-5 times a day in the airing and air-drying process, and the treatment lasts for 1-3 days.

9. The method according to claim 1, wherein the oil content of the air-dried mixture in step S5 is 0.8-1.5 wt%.

10. The device for treating oily sludge according to any one of claims 1 to 9, which comprises a pre-stirring system (1), a high-speed stirring cleaning device (2), a centrifugal dewatering device (3), a repairing device (4) and an oil collecting device (5), wherein the pre-stirring system (1), the high-speed stirring cleaning device (2), the centrifugal dewatering device (3) and the repairing device (4) are connected in sequence, and the oil outlet end of the high-speed stirring cleaning device (2) is communicated with the oil collecting device (5).