Three-phase horizontal screw centrifuge with water-saving viscosity-reducing pretreatment system

Abstract

The invention provides a three-phase horizontal screw centrifuge with a water-saving viscosity-reducing pretreatment system, which comprises a rotary drum, the center of the front end of the rotary drum is provided with a feed port, the feed port is connected with a straight pipe, the other end of the straight pipe is divided into two feed branches, one feed branch is a feed pipe, and the other feed branch is a water inlet pipe; a plurality of ultrasonic vibrators are distributed on the outer wall of the feeding pipe at intervals, are externally connected with an ultrasonic generator and are controlled by the ultrasonic generator to vibrate; the inlet end of the water inlet pipe is divided into two branches, one branch is connected with a water outlet pipeline through a water circulation system, the other branch is connected with an external water supplementing pipeline, and a water supplementing valve is arranged on the external water supplementing pipeline. The pretreatment steps of the oily sludge are simplified, a water recycling system is additionally arranged, the time cost and economic cost of pretreatment are remarkably reduced, efficient, green and low-consumption treatment of the oily sludge and efficient recycling of water resources are achieved, and the method is particularly suitable for drought areas or areas lack of water resources.

Description

Technical Field

[0001] The invention relates to the technical field of separation equipment, and in particular to a three-phase horizontal screw centrifuge with a water-saving and viscosity-reducing pretreatment system. Background Art

[0002] Oily sludge is one of the main solid wastes generated during oil exploration, mining, refining, processing, storage, and transportation. It has the characteristics of large output, high oil content, high proportion of heavy oil components, limited comprehensive utilization methods, and great difficulty in treatment. It is a widely distributed pollution source with significant environmental impact. How to achieve the reduction, harmlessness, and resource utilization of oily sludge has become a key issue that needs to be urgently addressed in the oil industry and environmental protection field.

[0003] Since the main components of oily sludge are oil, water and solid phases, the three-phase horizontal screw centrifuge can achieve better separation effect when separating oily sludge. The three-phase horizontal screw centrifuge uses the principle of centrifugal sedimentation to separate the three-phase mixture, but when the viscosity of the oily sludge is high, the centrifugal sedimentation separation effect becomes poor, which limits the use of the three-phase horizontal screw centrifuge, making the pretreatment of the material to reduce the viscosity a necessary step. However, the traditional pretreatment process has the problem of high dependence on water resources and chemical agents, and requires special equipment such as stirring tanks, which not only increases the floor space, but also increases equipment investment and increases the treatment cost. In arid or water-scarce areas, the treatment of oily sludge faces more severe challenges. If the recycling of water resources in the sludge can be achieved, the treatment cost and energy consumption can be effectively reduced.

[0004] At present, people have tried many solutions to this problem. For example:

[0005] CN201910972425.1 discloses a flocculant feed pipe for a horizontal screw centrifuge, which is designed with a feed pipe and a flocculant buffer pipe, increases the contact surface between the flocculant buffer and the separated material, and reduces the impact on the normal feeding of the separated material through the bullet-like structure of the nozzle itself. This horizontal centrifuge needs to add flocculant chemicals during the pretreatment process.

[0006] CN202123156042.9 discloses a feed pipe structure of a horizontal screw centrifuge, which adds a water inlet pipe and an annular jacket to prevent the problem of material blockage in the horizontal screw centrifuge. However, the design of this water inlet pipe and annular jacket is set along the feed pipe body, the purpose is to flush the cloth auxiliary bin to avoid material blockage, rather than to reduce the feed viscosity of the feed port during the feeding process.

[0007] CN202110267229.1 discloses a process system for recovering oil from high-concentration sludge, which can simultaneously achieve three-phase separation of oil, water and mud, solving the problem of further oil-water separation after separation of solid and liquid phases. Although the process system uses three-phase separation, it is necessary to add a demulsifier to the fluidized bed tank in the process flow, that is, flocculant-type chemical agents still need to be added during the treatment process.

[0008] CN202321614939.8 discloses a sludge treatment system, including a sludge tank, a sludge feed pump, a filter device, a PAM foaming box, a dosing pump and a horizontal screw centrifuge, which solves the problems of wear of the horizontal screw centrifuge, uneven mixing, low utilization rate of chemical agents, etc. Similarly, during the treatment process, it is necessary to use a dosing pump to add PAM chemical agents.

[0009] CN201710226157.7 discloses a process and device for deliquoring oily sludge, which also requires adding a certain concentration of oxidant, acidifier and surfactant to the oily sludge, and uses a treatment technology that combines mechanical equipment with regulating agents to achieve on-site rapid deliquoring of the oily sludge, reduce the volume of the oily sludge, and achieve drying of the oily sludge, creating conditions for the transportation and centralized treatment of the oily sludge.

[0010] CN202021107696.5 discloses a waste oil sludge treatment system, which includes a pretreatment unit and a separation unit, and realizes the complete separation of oil, water and mud in oil sludge pollutants, and realizes the harmless treatment of oil sludge pollutants and the recycling and reuse of resources. First, a two-phase horizontal screw centrifuge is used to separate oil and mud, and then a three-phase horizontal screw centrifuge is used to separate oil, water and mud, which involves many mechanical equipment and occupies a large space.

[0011] The prior art usually requires pretreatment when treating oily sludge. Traditional feed pipes are usually straight cylindrical structures and can only transport oily sludge. Chemical agents (such as flocculants, demulsifiers, etc.) are often added during the pretreatment process to achieve the separation of oil in the water-in-oil system and water in the oil-in-water system through chemical reactions (such as emulsification, oxidation, etc.). In addition, heating and stirring treatments are required to reduce the viscosity of the sludge and increase its fluidity, which requires stirring and mixing equipment that occupies a large area. Subsequently, subsequent separation treatment is carried out through a three-phase centrifugal device.

[0012] Based on the above problems, it is necessary to design a three-phase horizontal screw centrifuge with a water-saving and viscosity-reducing pretreatment system for its application in the separation and treatment of oily sludge resources. Summary of the invention

[0013] The technical problem to be solved by the present invention is: in order to overcome the shortcomings of the prior art, the present invention provides a three-phase horizontal screw centrifuge with a water-saving and viscosity-reducing pretreatment system, which simplifies the pretreatment steps of oily sludge, adds a water recycling system, and significantly reduces the time cost and economic cost of pretreatment. At the same time, through optimized design, efficient recycling of water resources is achieved, providing a scientific and feasible solution for efficient, green and low-consumption treatment of oily sludge, which is particularly suitable for arid or water-scarce areas.

[0014] The technical solution adopted by the present invention to solve its technical problems is: a three-phase horizontal screw centrifuge with a water-saving and viscosity-reducing pretreatment system, comprising a drum, wherein the front center of the drum is provided with a feed port, the lower bottom of the front end is provided with a slag discharge port, the rear end of the drum is provided with an oil outlet, the lower bottom of the rear end is provided with a water outlet, the oil outlet pipeline is connected to an oil tank, and the slag discharge port pipeline is connected to a solid slag recovery tank; the feed port is connected to a straight pipe, and the other end of the straight pipe is divided into two and has two feed branches, one feed branch is a feed pipe, and the other feed branch is a water inlet pipe; a plurality of ultrasonic vibrators are arranged at intervals on the outer wall of the feed pipe, the ultrasonic vibrators are externally connected to an ultrasonic generator, and the vibration is controlled by the ultrasonic generator; the inlet end of the water inlet pipe is divided into two, one branch is connected to the water outlet pipeline through a water circulation system, and the other branch is connected to an external water supply pipeline, and a water supply valve is provided on the external water supply pipeline.

[0015] In the above scheme, on the basis of the existing three-phase horizontal screw machine, the feed port is further improved and designed. During the feeding process, the muddy and oily dirt can be pre-treated and the oily sludge can be effectively crushed, so that the viscosity can be effectively reduced when entering the horizontal screw machine drum, and the feeding efficiency and separation efficiency can be improved. At the same time, the water circulation system is used to realize the recycling of water resources, greatly saving water resources and avoiding resource waste and environmental pollution.

[0016] Furthermore, in order to reduce the viscosity of the oil, a heating pipe is provided in the straight pipe, and the heating pipe is inserted into the straight pipe from the bifurcation position of the feed branch of the straight pipe. The oil viscosity can be reduced by heating, the separation of oil and water can be promoted, and the oil can be separated from the sludge to form a floating oil layer or a separable oil phase.

[0017] Furthermore, the water circulation system includes a centrifugal pump, a cyclone separator, a first screw pump, a water storage tank, a second screw pump and a circulation valve connected in sequence by pipelines; one side of the top of the cyclone separator is connected to the centrifugal pump pipeline, the upper end of the top is connected to the first screw pump pipeline, and the bottom of the cyclone separator is connected to the solid residue recovery tank through a pipeline. Through the setting of water circulation, on the one hand, the circulating water can be used to flush the straight pipe of the feed to prevent mud and oil from sticking to the wall, and the mud and oil can also be diluted to improve the separation efficiency. On the other hand, the separated water can be collected and the circulating water can be reused. Through the efficient recycling of water resources, the problem of water shortage is alleviated and the waste of water resources is reduced.

[0018] Furthermore, an adjustable nozzle capable of adjusting the water spraying velocity is provided on the branch line connecting the water inlet pipe and the external water supply pipeline. By adjusting the adjustable nozzle, the water supply velocity at the water inlet pipe can be controlled as required, and water resources can be utilized as required.

[0019] Furthermore, the adjustable nozzle is in the form of a columnar structure with a water hole extending therethrough. One end of the columnar structure is convex with an installation end and the other end is provided with a water outlet. The end of the columnar structure with the water outlet is inserted into a branch line of a water inlet pipe, and the installation end and the branch line end are detachably fixed. A throttle valve for adjusting the water outlet flow rate of the water outlet is provided in the columnar structure.

[0020] The beneficial effect of the present invention is that the three-phase horizontal screw centrifuge with a water-saving and viscosity-reducing pretreatment system provided by the present invention has a reasonable structural design and can realize multi-stage synchronous pretreatment operations, including the breaking up, crushing and viscosity reduction of oily sludge, effectively improving the sludge treatment efficiency, and there is no need to pretreat the oily sludge by adding chemical reagents, thereby avoiding the risk of residual chemical components in the separated material and ensuring the green environmental protection of the treatment process. At the same time, it has a water circulation system, which can effectively recycle and recycle the separated water resources, realizing the recycling of water resources on the one hand, and reducing the consumption of clean water resources on the other hand. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0022] Figure 1 It is a structural schematic diagram of a three-phase horizontal screw centrifuge in the optimal embodiment of the present invention.

[0023] Figure 2 Schematic diagram of an adjustable nozzle in the best embodiment of the present invention.

[0024] Figure 3 It is a schematic diagram of the best embodiment of the present invention.

[0025] In the figure, 1, water inlet pipe 2, feed pipe 3, heating pipe 4, straight pipe 5, drum 6, oil outlet 7, water outlet 8, slag discharge port 9, ultrasonic vibrator 10, adjustable nozzle 11, ultrasonic generator 12, solid slag recovery tank 13, oil tank 14, centrifugal pump 15, cyclone separator 16, first screw pump 17, water storage tank 18, second screw pump 19, circulation valve 20, water supply valve 21, water supply pipeline 101, water spray port 102, adjustment knob 102, and installation end. DETAILED DESCRIPTION

[0026] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention, and directions and references (e.g., up, down, left, right, etc.) may only be used to help describe the features in the drawings. Therefore, the following specific embodiments are not to be taken in a limiting sense, and the scope of the subject matter claimed is limited only by the attached claims and their equivalents.

[0027] like Figures 1 to 3 The three-phase decanter centrifuge with a water-saving and viscosity-reducing pretreatment system is the best embodiment of the present invention. The three-phase decanter centrifuge includes a drum 5. The improvement of the three-phase decanter centrifuge in this embodiment lies in pretreatment and water circulation. The main structure of the drum 5 is the same as that of the existing decanter centrifuge, and will not be repeated here.

[0028] Specifically, Figure 1 As shown, corresponding to the three-phase separated feed and three-phase separate discharge, the drum 5 has a feed port at the front center and a slag discharge port 8 at the lower bottom of the front end, an oil outlet 6 at the rear end of the drum 5 and a water outlet 7 at the lower bottom of the rear end, the oil outlet 6 is connected to an oil tank 13 through a pipeline, and the slag discharge port 8 is connected to a solid slag recovery tank 12 through a pipeline.

[0029] The feed port is connected to a straight pipe 4, and the other end of the straight pipe 4 is divided into two with two feed branches, one of which is the feed pipe 2 and the other is the water inlet pipe 1. The outer wall of the feed pipe 2 is divided into a plurality of ultrasonic vibrators 9, which are externally connected to an ultrasonic generator 11 and controlled to vibrate by the ultrasonic generator 11. The inlet end of the water inlet pipe 1 is divided into two, one of which is connected to the water outlet 7 pipeline through a water circulation system, and the other is connected to an external water supply pipeline 21, and a water supply valve 20 is provided on the external water supply pipeline 21.

[0030] like Figure 3As shown, the water circulation system includes a centrifugal pump 14, a cyclone separator 15, a first screw pump 16, a water storage tank 17, a second screw pump 18 and a circulation valve 19 which are connected in sequence by pipelines; one side of the top of the cyclone separator is connected to the pipeline of the centrifugal pump 14, the upper end of the top is connected to the pipeline of the first screw pump 16, and the bottom of the cyclone separator is connected to the solid slag recovery tank 12 through a pipeline.

[0031] An adjustable nozzle 10 is provided on the branch line connecting the water inlet pipe 1 and the external water supply pipe 21. Figure 2 As shown, the adjustable nozzle 10 is a columnar structure, a water hole is provided in the columnar structure, one end of the columnar structure is convex with a mounting end 102, and the other end is provided with a water outlet 101, the end of the columnar structure with the water outlet 101 is inserted into the branch line of the water inlet pipe 1, and the mounting end 102 and the branch line end are detachably fixed. A throttle valve for adjusting the water flow rate of the water outlet 101 is provided in the columnar structure. In the selection of the throttle valve, a valve that controls the valve opening by electromagnetic or other manual means can be used but is not limited to, so that after the overall system is assembled and the throttle valve is installed in the columnar structure, the valve opening can be adjusted and controlled from the outside, thereby adjusting the water flow rate of the water outlet 101 as needed.

[0032] Through the setting of the water circulation system, on the one hand, the circulating water can be used to flush the straight pipe 4 of the feed to prevent mud and oil from sticking to the wall, and the mud and oil can be diluted to improve the separation efficiency. On the other hand, the separated water can be collected and the circulating water can be reused. Through the efficient recycling of water resources, the problem of water shortage is alleviated and the waste of water resources is reduced.

[0033] On the basis of the above water replenishment, in order to further reduce the viscosity of the oil pollution, a heating pipe 3 is provided in the straight pipe 4, and the heating pipe 3 is inserted into the straight pipe 4 from the bifurcation position of the feed branch of the straight pipe 4. Heating can reduce the viscosity of the oil, promote the separation of oil and water, and separate the oil from the sludge to form a floating oil layer or a separable oil phase.

[0034] Working principle: First, the oily sludge enters the feed pipe 2, and the ultrasonic vibrator 9 controlled by the ultrasonic generator 11 starts to vibrate on the outer wall to break up the oily sludge; at the same time, the adjustable nozzle 10 starts to spray water into the water inlet pipe 1 to dilute the oily sludge; the heating pipe 3 starts to heat and increase the temperature in the straight pipe 4 to reduce the viscosity of the oily sludge; then the oily sludge is separated by a three-phase horizontal screw centrifuge; finally, the separated water is recovered to the water storage tank 17 for the adjustable nozzle 10 to spray water.

[0035] In this system, oily sludge is sucked into the system through the feed pipe 2. The ultrasonic generator 11 starts to work, so that the ultrasonic vibrator 9 starts to work on the outer wall of the feed pipe 2, generating high-intensity sound wave vibrations, and the sound energy acts on the oil droplets in the sludge to break and disperse the oil droplets and increase the surface area of ​​the oil droplets. At the same time, the sound wave energy can also weaken the binding force between the sludge particles, promote the extrusion of water in the sludge, increase its fluidity, and smoothly enter the feed straight pipe 4.

[0036] Open the water supply valve 20, and the water supply pipeline 21 provides part of the water source. The adjustable nozzle 10 is adjusted to the high-speed water spray state by adjusting the knob 102, and combined with ultrasonic vibration, the oily sludge is broken and scattered at the junction, further increasing the surface area of ​​the oil droplets and accelerating the oil-water separation process. The impact force and high-speed rotation of the water spray separate the oil droplets from the water to form a floating oil layer or a separable oil phase, and stir and evenly distribute the sludge to improve its fluidity. In addition, the water spray can also clean the straight pipe 4 to prevent the oily sludge from sticking to the wall.

[0037] After the oily sludge enters the straight pipe 4, the heating pipe 3 starts to work, reducing the viscosity of the oil by heating, promoting the separation of oil and water, and separating the oil from the sludge to form a floating oil layer or a separable oil phase.

[0038] Then, the oil, water and solid phases are separated after being processed by the three-phase horizontal screw centrifuge. The separated oil is recovered to the oil tank 13, the solid residue is discharged into the solid residue recovery tank 12, and the water is sucked into the cyclone separator 15 by the centrifugal pump 14. Considering the large workload of the three-phase horizontal screw centrifuge and the high water content of the oily sludge, the separated water may contain a small amount of solid residue and a small amount of oil.

[0039] Finally, water and solid are separated again by the cyclone separator 15, and the separated solid slag is discharged into the solid slag recovery tank 12, and the separated water is sucked back into the water storage tank 17 by the first screw pump 16. At the same time, the circulation valve 19 is opened and the water replenishment valve 20 is closed. The water storage tank 17 can provide the adjustable nozzle 10 with continuous high-speed water spraying under the action of the second screw pump 18, thereby forming a water recycling system.

[0040] Through the above operations, the designed water-saving and viscosity-reducing pretreatment system not only significantly shortens the pretreatment time, but also improves the significance of the pretreatment effect. At the same time, the system designs a water recycling scheme for water-scarce areas. Through the efficient recycling of water resources, it alleviates the problem of water shortage, reduces the waste of water resources, and plays a positive role in environmental protection.

[0041] Different from the existing three-phase decanter centrifuge in which the feed pipe 2 is usually a straight cylindrical structure and can only transport oily sludge, the three-phase decanter centrifuge with a water-saving and viscosity-reducing pretreatment system provided in this embodiment is designed as a forked Y-shape at the inlet end of the straight pipe 4, and the water inlet pipe 1 and the feed pipe 2 can realize the simultaneous transportation of water and oily sludge, thereby effectively reducing the viscosity of the oily sludge and improving the treatment efficiency. The material feeding process is combined with the viscosity-reducing pretreatment process to achieve the synchronous work of the two, thereby significantly reducing the time cost of the treatment and improving the operation efficiency.

[0042] At the same time, the three-phase horizontal screw centrifuge feed viscosity reduction pretreatment device provided in this embodiment uses a multi-stage physical method to synchronously reduce the viscosity of the oily sludge, avoiding the use of chemical agents, not only improving the treatment effect, but also ensuring the green environmental protection of the separation process. Specifically, in the feeding process, in the feeding design, an ultrasonic vibrator 9 is attached to the outer wall of the oily sludge feed pipe 2. The vibrator generates vibration during operation, so that the oily sludge is further broken and dispersed during the feeding process, thereby improving the pretreatment effect. At the same time, it is equipped with a water inlet pipe 1, and the feed is sprayed with water using an adjustable nozzle 10, which can not only effectively break up and break up the oily sludge, but also clean the inner wall of the feed pipe 2, significantly reducing the phenomenon of oily sludge adhering to the pipe wall or clogging at the junction of the pipe. And a heating pipe 3 is installed at the bifurcation position of the Y-shaped, so that the oily sludge entering the straight pipe 4 section reduces the viscosity under the heating effect, thereby improving the effect of subsequent separation treatment. This pretreatment method can realize multi-stage synchronous pretreatment operations, including the breakup, crushing and viscosity reduction of oily sludge, effectively improving the sludge treatment efficiency. There is no need to pretreat the oily sludge by adding chemical reagents, thus avoiding the risk of residual chemical components in the material after separation and ensuring the green and environmentally friendly treatment process.

[0043] At the same time, this embodiment combines the three-phase horizontal screw centrifuge, the cyclone separator 15 and the adjustable nozzle 10 to construct a water recycling system. On the one hand, the cyclone separator 15 can achieve secondary separation, and more thoroughly separate and treat water and solid residue, further improving the separation efficiency and treatment effect. On the other hand, the system can effectively recycle and recycle the separated water resources, significantly save the use of water resources, and reduce the consumption of clean water resources in the pretreatment process.

[0044] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A three-phase horizontal screw centrifuge with a water-saving and viscosity-reducing pretreatment system, characterized in that: The drum (5) comprises a feed port at the center of the front end of the drum (5) and a slag discharge port (8) at the bottom of the front end; an oil outlet (6) at the rear end of the drum (5) and a water outlet (7) at the bottom of the rear end; the oil outlet (6) is connected to an oil tank (13) through a pipeline; and the slag discharge port (8) is connected to a solid slag recovery tank (12) through a pipeline; The feed port is connected to a straight pipe (4), and the other end of the straight pipe (4) is divided into two and has two feed branches, one of which is a feed pipe (2) and the other is a water inlet pipe (1); The outer wall of the feed pipe (2) is provided with a plurality of ultrasonic vibrators (9) at intervals, and the ultrasonic vibrators (9) are externally connected to an ultrasonic generator (11), and the vibration is controlled by the ultrasonic generator (11); The inlet end of the water inlet pipe (1) is divided into two parts, one of which is connected to the water outlet (7) pipeline through a water circulation system, and the other is connected to an external water supply pipeline (21), and a water supply valve (20) is provided on the external water supply pipeline (21).

2. A three-phase decanter centrifuge with a water-saving and viscosity-reducing pretreatment system as claimed in claim 1, characterized in that: A heating pipe (3) is arranged in the straight pipe (4), and the heating pipe (3) is inserted into the straight pipe (4) from the bifurcation position of the feed branch of the straight pipe (4).

3. A three-phase decanter centrifuge with a water-saving and viscosity-reducing pretreatment system as claimed in claim 1, characterized in that: The water circulation system comprises a centrifugal pump (14), a cyclone separator (15), a first screw pump (16), a water storage tank (17), a second screw pump (18) and a circulation valve (19) which are sequentially connected by pipelines; One side of the top of the cyclone separator is connected to the pipeline of the centrifugal pump (14), and the upper end of the top is connected to the pipeline of the first screw pump (16), and the bottom of the cyclone separator is connected to the solid slag recovery tank (12) through a pipeline.

4. A three-phase decanter centrifuge with a water-saving and viscosity-reducing pretreatment system as claimed in claim 1, characterized in that: An adjustable nozzle (10) capable of adjusting the water spraying flow rate is provided on the branch line connecting the water inlet pipe (1) and the external water supply pipeline (21).

5. A three-phase decanter centrifuge with a water-saving and viscosity-reducing pretreatment system as claimed in claim 5, characterized in that: The adjustable nozzle (10) is in the form of a columnar structure, a water hole is provided in the columnar structure, one end of the columnar structure is protruding and has a mounting end (102), and the other end is provided with a water spraying port (101), the end of the columnar structure having the water spraying port (101) is inserted into a branch line of the water inlet pipe (1), and the mounting end (102) and the branch line end are detachably fixed; a throttle valve for adjusting the water flow rate of the water spraying port (101) is provided in the columnar structure.

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