An anti-flushing slag removal device and slag removal method for treating oily sewage

Abstract

The present invention relates to a slag removal device and a slag removal method with backwashing for treating oily sewage. The slag removal device comprises a box body, an upper weir plate, a lower weir plate, a filter screen, and a water inlet device. The upper weir plate is fixedly connected to the opening of the box body. The lower weir plate is fixedly installed inside the box body. The filter screen is fixedly installed inside the frustum cavity. The filter screen is located directly below the lower weir plate. The water inlet device is communicated with the box body, and the water inlet end is lower than the filter screen and higher than the bottom end of the lower weir plate. In the present invention, solid-phase waste residues in the oily sewage are intercepted at the bottom of the box body through the filter screen. The upper weir plate is used to filter floating slag, and the lower weir plate is used for intercepting and buffering. When discharging the solid-phase waste residues, backwashing of the filter screen is formed by the drop of the oily sewage liquid level, and the solid-phase waste residues blocked or attached to the filter screen are washed and discharged. The slag removal device of the present invention not only has high slag removal accuracy, fast efficiency, and anti-blocking performance, but also has the advantages of energy conservation, environmental protection, and reduction of treatment costs.

Description

Technical Field

[0001] The present invention relates to a slag removal device, in particular to a backwashing slag removal device for treating oily sewage and a backwashing slag removal method for treating oily sewage. Background Art

[0002] In domestic wastewater or catering wastewater, due to the presence of leftovers such as rice and vegetables, a large amount of oil is formed in the wastewater, resulting in oily sewage, which cannot be directly discharged into nearby water sources. If oily sewage is not treated in time, it will produce odors and cause greater pollution to the atmosphere, soil, water sources, etc.

[0003] During the treatment of oily sewage, it generally undergoes two main steps, namely solid-liquid separation and oil-water separation. Solid-liquid separation is also known as slag removal, that is, separating the solid-phase waste residue in the oily sewage from the oil and water. As the previous process of oil-water separation, whether the slag removal can be accurate and efficient has an important impact on the oil-water separation process.

[0004] In the existing solid-liquid separation process, a part is carried out synchronously with oil-water separation, that is, directly using static sedimentation to divide the oily sewage into an oil layer, a water layer and a sludge layer, and then recovering the oil layer and directly discharging the water layer and the sludge layer. Although this method reduces the treatment process and treatment cost, the sludge layer occupies the effective volume of the oil-water separation device, interferes with the oil-water separation process, and reduces the overall separation efficiency. At the same time, the scum suspended or floating in the oily sewage cannot be directly filtered out, and the purity of the recovered oil is not high. Another part directly uses a slag removal device for solid-liquid separation. If a filtering device is used in the slag removal device to filter out the solid-phase waste residue, there is a risk of blockage of the filtering device and it is difficult to filter for a long time. If only static sedimentation is used to filter out the solid-phase waste residue, it is not only difficult to filter out the suspended substances therein, but also reduces the efficiency of solid-liquid separation. Summary of the Invention

[0005] Based on this, in view of the problems of low slag removal efficiency and poor slag removal effect existing in the existing slag removal device, it is necessary to provide a backwashing slag removal device and a slag removal method for treating oily sewage.

[0006] The present invention is realized through the following technical solutions: A backwashing slag removal device for treating oily sewage includes a box body, an upper weir plate, an overflow box, a discharge device, a lower weir plate, a filter screen, a water inlet device, an oil discharge pipe, a heating device, an oil suction device, a flow meter, a temperature sensor, a liquid level meter, an oil content detector and a controller.

[0007] Inside the box body, there is a cavity for accumulating oily sewage. The cavity includes a frustum cavity at the top and an inverted frustum cavity at the bottom. The upper weir plate is fixedly connected to the opening of the box body. The upper weir plate is a hollow cylindrical structure, and the inner cavity of the upper weir plate communicates with the frustum cavity. The top end of the upper weir plate is provided with a serrated structure. The overflow box is fixedly connected to the outer wall of the box body and houses the upper weir plate. The overflow box is a hollow cylinder or a hollow cuboid, etc., which is used to accumulate the oil liquid discharged through the upper weir plate. The discharge device communicates with the bottom of the box body and is used to discharge the oily sewage at the bottom of the box body.

[0008] The lower weir plate is fixedly installed in the frustum cavity. The lower weir plate is also a hollow cylindrical structure, and the bottom end of the lower weir plate is also provided with a serrated structure. The filter screen is a hemispherical structure. The filter screen is fixedly installed in the frustum cavity, dividing the inner cavity of the box body into an upper overflow cavity and a lower isolation cavity. And the filter screen is located directly below the lower weir plate. The water inlet device communicates with the box body and is used to transport oily sewage into the box body. The connection part of the water inlet device and the box body is located below the filter screen and not lower than the bottom end of the lower weir plate.

[0009] The above slag removal device introduces the oily sewage into the box body through the water inlet device, intercepts the solid waste residue in the oily sewage through the filter screen at the bottom of the box body. At the same time, the lower weir plate buffers the incoming oily sewage to avoid impacting the stratified or stratifying oily sewage and maintain the separation efficiency of the oily sewage in the box body. When the oily sewage below a preset height in the box body meets the discharge standard, this part of the oily sewage is completely discharged, and at the same time, a backwash is formed on the filter screen to wash and discharge the solid waste residue blocked or attached to the filter screen. The above slag removal device not only has the advantages of high slag removal accuracy, fast efficiency, and anti-blocking, but also has the advantages of energy conservation, environmental protection, and reduced treatment costs.

[0010] In one embodiment, the oil discharge pipe communicates with the bottom end of the overflow box and is used to discharge the oil liquid in the overflow box. The end of the oil discharge pipe communicating with the overflow box is higher than the other end of the oil discharge pipe, so that the oily sewage in the overflow box is directly discharged out under the action of gravity.

[0011] In one embodiment, the water inlet device includes a water pump, a water inlet pipe, and an electric valve I. One end of the water inlet pipe communicates with the box body, and the other end of the water inlet pipe communicates with the water pump. The end of the water inlet pipe close to the box body is below the filter screen and higher than the bottom end of the lower weir plate. The electric valve I is installed on the water inlet pipe and is used to control the on-off state of the water inlet pipe.

[0012] In one embodiment, the heating device is installed at the end of the water inlet pipe close to the box body. The heating device is an infrared heater or a carbon fiber heater. The oily sewage is preheated through the heating device so that the temperature of the oily sewage introduced into the box body is not less than a preset temperature, so that the solid-phase oil in the oily sewage melts into liquid-phase oil and maintains the fluidity of the oil liquid.

[0013] In one embodiment, the oil suction device includes an oil pump, an oil suction pipe, and an electric valve II. One end of the oil suction pipe communicates with the box body, and the other end of the oil suction pipe communicates with the oil pump. The end of the oil suction pipe close to the box body is higher than the end of the water inlet pipe close to the box body. The electric valve I is installed on the water inlet pipe to control the on-off state of the water inlet pipe.

[0014] In one embodiment, the discharge device includes a sludge pump, a drain pipe, and an electric valve III. One end of the drain pipe communicates with the bottom of the box body, and the other end of the drain pipe communicates with the sludge pump. The electric valve III is installed on the drain pipe to control the on-off state of the drain pipe.

[0015] In one embodiment, a flow meter is installed on the water inlet device to measure the water inlet rate v of the water inlet device in real time. A temperature sensor is installed inside the water inlet device to measure the average temperature T of the oily sewage at the water outlet end of the water inlet device. A liquid level gauge is installed inside the box body to measure the depth h of the oily sewage in the box body. An oil content detector is installed on the box body to detect the oil content ω1 of the oily sewage at the upper limit and the oil content ω2 of the oily sewage at the lower limit. The upper limit is located between the lower weir plate and the inner wall of the box body, and the lower limit is not higher than the filter screen.

[0016] The controller is used for: First, controlling the water inlet device to inlet water at the maximum power. At the same time, query the heating power P in a conversion table according to the water inlet rate v, and then heat the oily sewage according to the heating power P so that the average temperature T is within a preset temperature range. The conversion table represents the mapping relationship between the water inlet rate v and the heating power P.

[0017] Second, judging whether the depth h reaches a preset height h0. If so, controlling the water inlet device to inlet water at a preset water inlet rate v0.

[0018] Third, judging whether the oil content ω2 is lower than a preset threshold ω0. If so, controlling the discharge device to start until the depth h is lower than a preset depth h2.

[0019] Fourth, judging whether the oil content ω1 is higher than a preset threshold ω h , if so, discharging the oil liquid located between the lower weir plate and the inner wall of the box body.

[0020] The present invention also provides a slag removal method for backwashing oily sewage. The slag removal method includes the following processes:

[0021] S1: Heat the oily sewage and then introduce it into the box body. The specific process of the water inlet of the oily sewage is as follows:

[0022] Judge whether the depth h of the oily sewage in the box body is lower than a preset depth h0. If so, the oily sewage is inlet at the maximum water inlet rate vmax Water inlet. Otherwise, the oily sewage enters at a rate of v0. Query the corresponding heating power P in a pre-stored conversion table according to the inlet rate v of the oily sewage, and then heat the oily sewage according to the heating power P so that the average temperature T of the oily sewage is within a preset temperature range. The conversion table represents the mapping relationship between the inlet rate v and the heating power P.

[0023] S2: Filter the solid waste residue in the oily sewage.

[0024] S3: Filter the scum in the oily sewage.

[0025] S4: Drain the oil layer or the oil-water mixed layer formed after the oily sewage is stratified in the box body.

[0026] S5: Drain the separated sludge. Among them, the discharge condition of the sludge is that the oil content ω2 at the lower limit is lower than a preset threshold ω0.

[0027] In one embodiment, the solid waste residue is filtered out by the following method: Install a filter screen in the box body. The oily sewage enters from below the filter screen and then is discharged through the top of the box body. The solid waste residue in the oily sewage is intercepted below the filter screen, and the solid waste residue is discharged through the sewage discharge device, and at the same time, the solid waste residue blocked on the filter screen is backwashed.

[0028] In one embodiment, the scum is filtered out by the following method: Set the outlet of the box body as a serrated structure, and the oily sewage flows out in all directions through the serrated structure, and the scum is intercepted in the box body through the serrated structure.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The slag removal device of the present invention introduces the oily sewage into the box body through the water inlet device, intercepts the solid waste residue in the oily sewage at the bottom of the box body through the filter screen. At the same time, the lower weir plate buffers the incoming oily sewage to avoid impacting the already stratified or being stratified oily sewage, and maintains the separation efficiency of the oily sewage in the box body. When the oily sewage below a preset height in the box body meets the discharge standard, all this part of the oily sewage is discharged, and at the same time, the filter screen is backwashed to wash and discharge the solid waste residue blocked or attached to the filter screen. The slag removal device of the present invention not only has the advantages of high slag removal accuracy, fast efficiency and anti-blocking, but also has the advantages of energy conservation, environmental protection and reduced treatment cost.

[0031] 2. The slag removal device of the present invention filters out the scum in the oily sewage by installing upper and lower weir plates with serrated structures, reduces the amount of scum in the discharged oil liquid, and improves the purity of the oil liquid recovery.

[0032] 3. The slag removal device of the present invention measures the inlet rate, inlet temperature, and depth of the oily sewage in real time, and then adjusts the inlet rate and the output power of the heating device in real time. This not only can convert the solid-phase oil in the oily sewage into liquid-phase oil to avoid clogging of the filter screen by solid-phase oil, but also adjusts the output rate of the heating device in real time according to the inlet rate, so as to meet the heating conditions of the oily sewage while reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 FIG. is a schematic three-dimensional structure diagram of the backwashing type slag removal device for oily sewage according to Embodiment 1 of the present invention;

[0034] Figure 2 is Figure 1 the schematic three-dimensional sectional structure diagram of the slag removal device in

[0035] Figure 3 is Figure 1 the schematic front sectional structure diagram of the slag removal device in

[0036] Figure 4 is Figure 1 the schematic position diagram of the slag removal device in for treating oily sewage;

[0037] Figure 5 is Figure 1 the flow chart of the slag removal device in for treating oily sewage;

[0038] Figure 6 FIG. is the step diagram of the backwashing type slag removal method for oily sewage according to Embodiment 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] It should be noted that when a component is referred to as being "installed on" another component, it can be directly on the other component or there may also be an intermediate component. When a component is considered to be "arranged on" another component, it can be directly arranged on the other component or there may be an intermediate component at the same time. When a component is considered to be "fixed to" another component, it can be directly fixed to the other component or there may be an intermediate component at the same time.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this invention belongs. The terms used in the description of the present invention herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "or / and" as used herein includes any and all combinations of one or more of the related listed items.

[0042] Embodiment 1

[0043] Please refer to Figure 1 、 Figure 2 and Figure 3 , Figure 1 which is a schematic three-dimensional structure diagram of the slag removal device for oil-containing sewage with a backwashing type in this embodiment; Figure 2 is Figure 1 a schematic three-dimensional sectional structure diagram of the slag removal device in Figure 3 is Figure 1 a schematic front sectional structure diagram of the slag removal device in . The slag removal device includes a box body 1, an upper weir plate 6, an overflow tank 2, a discharge device 7, a lower weir plate 5, a filter screen 4, a water inlet device, an oil discharge pipe 9, a heating device, an oil suction device, a flowmeter, a temperature sensor, a liquid level gauge, an oil content detector, and a controller.

[0044] A cavity for accumulating oil-containing sewage is arranged inside the box body 1. The cavity includes a frustum cavity at the top and an inverted frustum cavity at the bottom. The oil-containing sewage is introduced into the box body 1 and first accumulates at the bottom of the box body 1 along the inverted frustum cavity at the bottom. As the depth of the oil-containing sewage gradually increases, it finally flows out in all directions through the opening at the top of the box body 1.

[0045] The upper weir plate 6 is fixedly connected to the opening of the box body 1. The upper weir plate 6 is a hollow cylindrical structure, and the inner cavity of the upper weir plate 6 is communicated with the frustum cavity. The top end of the upper weir plate 6 is provided with a serrated structure. When the liquid level of the oil-containing sewage in the box body 1 is higher than the bottom end of the serrated holes of the upper weir plate 6, the oil liquid flows out of the upper weir plate 6 through the serrated holes, and part of the floating slag floating on the top of the oil-containing sewage is intercepted in the inner cavity of the upper weir plate 6 by the serrated structure, realizing the filtration of the floating slag.

[0046] The overflow tank 2 is fixedly connected to the outer wall of the box body 1 and houses the upper weir plate 6. The overflow tank 2 is a hollow cylinder or a hollow cuboid, etc., and is used to accumulate the oil liquid discharged through the upper weir plate 6. The overflow tank 2 and the upper weir plate 6 are eccentrically arranged so that an inclined elliptical structure is formed at the connection between the overflow tank 2 and the box body 1, and thus the oil liquid overflowing into the overflow tank 2 flows towards the bottom end of the overflow tank 2.

[0047] The drain pipe 9 is connected to the bottom end of the overflow tank 2 and is used to drain the oil liquid in the overflow tank 2. The end of the drain pipe 9 connected to the overflow tank 2 is higher than the other end of the drain pipe 9, so that the oily sewage in the overflow tank 2 can be directly discharged outwards under the action of gravity. The end of the drain pipe 9 far away from the overflow tank 2 can be connected to an oil storage barrel or an oil-water separation device, so as to further process the discharged oil liquid.

[0048] Please refer to Figure 4 , which is Figure 1 a schematic diagram of the position where the slag removal device in

[0049] processes the oily sewage. The water inlet device is connected to the box body 1 and is used to transport the oily sewage into the box body 1. The water inlet device includes a water pump, a water inlet pipe and an electric valve I. One end of the water inlet pipe is connected to the box body 1, and the other end of the water inlet pipe is connected to the water pump. The end of the water inlet pipe close to the box body 1 is below the filter screen 4 and higher than the bottom end of the lower weir plate 5. The electric valve I is installed on the water inlet pipe and is used to control the on-off state of the water inlet pipe. By adjusting the output power of the water pump and the switch state of the electric valve I, the water inlet rate can be controlled in real time by the water inlet device.

[0050] The filter screen 4 is of a hemispherical structure. The filter screen 4 is fixedly installed in the frustum cavity, dividing the inner cavity of the box body 1 into an upper overflow cavity and a lower isolation cavity. And the filter screen 4 is directly below the lower weir plate 5. The water outlet end of the water inlet pipe (the end close to the box body 1) is lower than the filter screen 4. When the oily sewage enters, the solid-phase waste residues with particle sizes larger than the mesh holes of the filter screen 4 are all filtered and retained in the isolation cavity, and then separated from the oily sewage by static sedimentation and accumulated along the inner wall of the box body 1 in the inverted frustum cavity. In this embodiment, the filter screen 4 is made of a stainless steel filter screen with a pore diameter of 5 mm. Of course, in other embodiments, the filter screen 4 can also be made of anti-corrosion materials such as plastics and nitinol alloys. At the same time, the hardness of the filter screen 4 should meet the requirement that the filter screen 4 does not deform under the long-term impact of the oily sewage. The pore diameter of the filter screen can also be larger or smaller, as long as it can meet the slag removal requirements.

[0051] In other embodiments, the box body 1 can also adopt a square box body that is symmetric up and down. Specifically, the inner cavity of the box body 1 includes a frustum cavity, a cuboid cavity, and an inverted frustum cavity from top to bottom. Correspondingly, both the upper weir plate 6 and the lower weir plate 5 are set as hollow cuboids and are coaxially arranged with the box body 1. The filter screen 4 can also be set as a square basket or an inverted frustum, etc., as long as it can filter out the solid waste residues in the oily sewage.

[0052] The discharge device 7 is communicated with the bottom of the box body 1 and is used to discharge the oily sewage at the bottom of the box body 1. The discharge device 7 includes a sludge pump, a drain pipe, and an electric valve III. One end of the drain pipe is communicated with the bottom of the box body 1, and the other end of the drain pipe is communicated with the sludge pump. The electric valve III is installed on the drain pipe and is used to control the on-off state of the drain pipe. When the sludge deposited at the bottom of the box body 1 has reached a preset depth or the oily sewage located below the lower limit reaches the discharge standard, the sludge pump can be started to discharge the sludge or the oily sewage. During the discharge process, the sewage liquid level gradually drops, and the oily sewage above the filter screen 4 moves to below the filter screen 4, forming a backwash of the filter screen 4 to wash out some of the solid waste residues attached to the filter screen 4 and prevent the filter screen 4 from being blocked. At the same time, the sludge settled in the oily sewage accumulates along the inner wall of the bottom of the box body 1 towards the drain pipe, so that the settled sludge can be discharged in time, avoiding the sludge accumulating at the bottom of the box body 1 for a long time, resulting in peculiar smell or coagulating into lumps and being difficult to discharge.

[0053] The heating device is installed at one end of the water inlet pipe close to the box body. The heating device is an infrared heater or a carbon fiber heater. The heating device preheats the oily sewage so that the temperature of the oily sewage introduced into the box body 1 is not less than a preset temperature (such as 40 °C), so as to melt the solid-phase oil in the oily sewage into liquid-phase oil and maintain the fluidity of the oil liquid. The heating device can adjust the heating power in real time according to the water inlet rate so that the inlet water temperature of the oily sewage is within a preset temperature range (such as 40 - 45 °C), which can not only maintain the smooth flow of the oil liquid, but also reduce energy consumption and save operation costs.

[0054] The oil suction device includes an oil pump, an oil suction pipe, and an electric valve II. One end of the oil suction pipe is connected to the box body 1, and the other end of the oil suction pipe is connected to the oil pump. The end of the oil suction pipe close to the box body 1 is higher than the end of the water inlet pipe close to the box body 1. The electric valve I is installed on the water inlet pipe to control the on-off state of the water inlet pipe. An upper-small-and-lower-large annular cavity is formed between the lower weir plate 5 and the inner wall of the box body 1. When the oily sewage enters, the scum with a particle size smaller than the filtration holes of the filter screen 4 can freely pass through the filter screen 4. Under the interception of the lower weir plate 5, the oily sewage first settles to the bottom of the box body 1. Then, as the liquid level rises, part of the scum suspends on the top surface of the oily sewage and is intercepted in the inner cavity of the upper weir plate 6 by the upper weir plate 6. A small part of the scum with too small a particle size (such as less than 0.1 mm) is discharged to the bottom of the overflow tank 2 through the upper weir plate 6. When the liquid level of the oily sewage is higher than the serrated structure of the lower weir plate 5, the oily sewage is intercepted in the annular cavity, and the scum with a density less than that of the oil accumulates at the top of the annular cavity. When the scum accumulates to a certain amount or the oil liquid in the annular cavity reaches the recovery standard, the oil liquid and scum in the annular cavity are sucked out through the oil suction device.

[0055] In this embodiment, the slag removal device introduces the oily sewage into the box body 1 through the water inlet device, intercepts the solid-phase waste residues in the oily sewage on the bottom of the box body 1 through the filter screen 4. At the same time, the lower weir plate 5 buffers the incoming oily sewage to avoid impacting the separated or separating oily sewage and maintain the separation efficiency of the oily sewage in the box body 1. When the oily sewage below a preset height in the box body 1 meets the discharge standard, this part of the oily sewage is completely discharged, and at the same time, a backwash is performed on the filter screen 4 to wash and discharge the solid-phase waste residues blocked or attached to the filter screen 4. The slag removal device of this embodiment not only has the advantages of high slag removal accuracy, fast efficiency, and anti-blocking, but also has the advantages of energy conservation, environmental protection, and reduced treatment costs.

[0056] The flowmeter is installed on the water inlet device to measure the water inlet rate v of the water inlet device in real time. The flowmeter can adopt a differential pressure flowmeter, a rotameter, an electromagnetic flowmeter, or an ultrasonic flowmeter, etc. If an ultrasonic flowmeter with the model number YL6000X-T is adopted, it not only has high measurement accuracy and good protection performance, but also operates stably and is easy to install, and can meet the measurement requirements of real-time flow and cumulative flow.

[0057] The temperature sensor is installed inside the water inlet device to measure the average temperature T of the oily sewage at the water outlet end of the water inlet device. Specifically, the temperature sensor is installed at the end of the water inlet pipe close to the box body 1. The temperature sensor can adopt a contact type temperature sensor or a non-contact type temperature sensor. If an infrared temperature sensor with the model number JXBS-3001-HW is adopted, it can perform non-contact temperature measurement on the oily sewage. It not only has high measurement accuracy, but also its operation is not affected by the oily sewage, realizing stable detection of the oily sewage.

[0058] The liquid level gauge is installed inside the box body 1 and is used to measure the depth h of the oily sewage inside the box body 1. The liquid level gauge can be a tuning fork vibration type, magnetic floating type, pressure type or ultrasonic type liquid level gauge. If a magnetic floating anti-corrosion type liquid level gauge with the model number JKM-UHZ is adopted, it can adapt to the measurement environment of the oily sewage, overcome the viscosity influence of the oily sewage, and realize accurate and continuous monitoring of the oily sewage.

[0059] The oil content detector is installed on the box body 1 and is used to detect the oil content ω1 of the oily sewage at the upper limit and the oil content ω2 of the oily sewage at the lower limit. The upper limit is located between the lower weir plate 5 and the inner wall of the box body 1, and the lower limit is not higher than the filter screen 4. The oil content detector can adopt an infrared oil detector with the model number TE-9900Plus, which not only has high measurement accuracy and high sensitivity, but also is easy to carry and can remotely transmit measurement data. Of course, in other embodiments, the oil content detector can also adopt a fluorescence oil detector, an ultraviolet oil detector, a nuclear magnetic resonance oil detector, etc.

[0060] Please combine Figure 5 with Figure 1 which is the flow chart of the oily sewage treated by the slag removal device in

[0061] The controller is used for: First, controlling the water inlet device to inlet water at the maximum power. At the same time, query the heating power P in a conversion table according to the water inlet rate v, and then heat the oily sewage according to the heating power P so that the average temperature T is within a preset temperature range. The conversion table represents the mapping relationship between the water inlet rate v and the heating power P. In the initial water inlet stage of the oily sewage, control the oily sewage to be introduced into the box body 1 at the maximum water inlet rate so that the box body 1 is quickly filled with the oily sewage. During this process, the oily sewage keeps slow separation, and the solid waste residue therein is intercepted below the filter screen 4. The heating device preheats the oily sewage so that the solid-phase oil in the oily sewage is converted into liquid-phase oil, avoiding the blockage of the filter screen 4 by the solid-phase oil, and at the same time, adjusting the output rate of the heating device in real time according to the water inlet rate so as to meet the heating conditions of the oily sewage while reducing energy consumption.

[0062] III. Determine whether the oil content ω2 is lower than a preset threshold ω0. If so, control the start of the discharge device 7 until the depth h is lower than a preset depth h2. When the oil content ω2 is lower than ω0, it indicates that the oily sewage located below the lower limit has reached the discharge standard and can be directly discharged. By measuring the depth h of the oily sewage in real time, it can be determined whether the oily sewage meeting the discharge standard has been completely discharged, that is, when the liquid level drops below the depth h2, a single discharge is completed. By detecting the oil content of the oily sewage and discharging the oily sewage meeting the preset conditions, automatic discharge of the oily sewage is formed, avoiding the risk of sludge caking and generating peculiar smell caused by untimely manual discharge, and even damaging the slag removal equipment.

[0063] IV. Determine whether the oil content ω1 is higher than a preset threshold ω h . If so, discharge the oil liquid between the lower weir plate 5 and the inner wall of the box body 1. When, it indicates that the oily sewage in the annular cavity reaches the recovery standard. While recovering the oil liquid, the floating slag is discharged together, reducing the probability of the floating slag being discharged through the upper weir plate 6, so that the purity of the oil liquid discharged through the upper weir plate 6 is higher after further oil-water separation.

[0064] Please refer to Figure 6 , which is the step diagram of the backwashing type slag removal method for oily sewage in this embodiment. This embodiment also provides a backwashing type slag removal method for oily sewage, and the slag removal method includes the following steps:

[0065] S1: Heat the oily sewage and introduce it into the box body. The specific process of the inlet of the oily sewage is as follows:

[0066] Determine whether the depth h of the oily sewage in the box body is lower than a preset depth h0. If so, the oily sewage enters at the maximum inlet rate v max . Otherwise, the oily sewage enters at the rate v0. In the initial inlet stage of the oily sewage, control the oily sewage to be introduced into the box body at the maximum inlet rate, so that the box body is quickly filled with the oily sewage. During this process, the oily sewage is slowly separated, and the solid waste residue is intercepted below the filter screen. When the box body is filled with the oily sewage (i.e., reaches the depth h0), in order to prevent the floating slag from being discharged through the sawtooth holes of the upper weir plate, the inlet rate is adjusted down to v0.

[0067] Query the corresponding heating power P in a pre-stored conversion table according to the influent rate v of the oily sewage, and then heat the oily sewage according to the heating power P so that the average temperature T of the oily sewage is within a preset temperature range. The conversion table represents the mapping relationship between the influent rate v and the heating power P. The heating device is used to preheat the oily sewage so that the solid-phase oil in the oily sewage is converted into liquid-phase oil, avoiding the blockage of the filter screen by solid-phase oil. At the same time, the output rate of the heating device is adjusted in real time according to the influent rate to meet the heating conditions of the oily sewage while reducing energy consumption. The conversion table can be obtained through preliminary experiments, that is, record the heating power corresponding to the heating device when the heating requirements are met at different influent rates. S2: Filter the solid waste residue in the oily sewage. The solid waste residue is filtered out by the following method:

[0068] Install a filter screen in the box. The oily sewage enters from below the filter screen and then is discharged from the top of the box. The filter screen is a hemispherical structure, and the edge of the filter screen is closely attached to the inner wall of the box or sealed, thereby dividing the box into an isolation chamber below the filter screen and an overflow chamber above the filter screen. The solid waste residue in the oily sewage is intercepted in the isolation chamber below the filter screen and then discharged through the sewage discharge device. While discharging the sewage, the liquid level of the oily sewage drops, backwashing the solid waste residue blocked on the filter screen to maintain the slag removal performance of the filter screen.

[0069] S3: Filter the floating scum in the oily sewage. The floating scum is filtered out by the following method:

[0070] Set the outlet of the box to a serrated structure, and the oily sewage flows out in all directions through the serrated structure. The floating scum is intercepted in the box through the serrated structure. In this embodiment, an upper weir plate is installed at the outlet of the box, and the top of the upper weir plate is set to a serrated structure to achieve the filtration of the floating scum. When the liquid level of the oily sewage reaches the bottom of the serrated structure, the oil liquid flows out in all directions through the serrated holes, and the floating scum is intercepted by the inverted triangular serrated holes, thereby achieving the removal of the floating scum.

[0071] S4: Discharge the oil layer or the oil-water mixed layer formed after the oily sewage is stratified in the box. The oily sewage is statically settled in the box and gradually stratified under the action of gravity. Among them, the oil layer with the smallest density and the oil-water mixed layer are directly discharged from the top of the box. The sludge layer settles at the bottom of the box.

[0072] S5: Discharge the separated sludge. Among them, the discharge condition of the sludge is that the oil content ω2 at the lower limit is lower than a preset threshold ω0. A sewage pump is used to discharge the sludge. According to the preset discharge standard, 1 / 3 of the total volume of the box is discharged each time, and then the corresponding discharge time is set, or the start and stop of the sewage pump are controlled according to the total depth of the oily sewage so that the discharged sludge or oily sewage meets the discharge standard.

[0073] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as falling within the scope described in this specification.

[0074] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A backwashing slag removal device for oily sewage, which comprises a box body, an upper weir plate, an overflow box and a discharge device; a cavity for accumulating oily sewage is arranged inside the box body; the cavity comprises a frustum cavity at the top and an inverted frustum cavity at the bottom; the upper weir plate is fixedly connected to the opening of the box body; the upper weir plate is a hollow cylindrical structure, and the inner cavity of the upper weir plate is communicated with the frustum cavity; the top end of the upper weir plate is arranged as a serrated structure; the overflow box is fixedly connected to the outer wall of the box body and houses the upper weir plate; the discharge device is communicated with the bottom of the box body and is used for discharging the oily sewage at the bottom of the box body; It is characterized in that The slag removal device further comprises: A lower weir plate, which is fixedly installed in the frustum cavity; the lower weir plate is also a hollow cylindrical structure, and the bottom end of the lower weir plate is also arranged as a serrated structure; A filter screen, which is a hemispherical structure; the filter screen is fixedly installed in the frustum cavity, separating the inner cavity of the box body into an upper overflow cavity and a lower isolation cavity; and the filter screen is located directly below the lower weir plate; and An inlet device, which is communicated with the box body and is used for conveying oily sewage into the box body; the connection part of the inlet device and the box body is located below the filter screen and not lower than the bottom end of the lower weir plate.

2. The slag removal device for oily sewage with a backwashing type according to claim 1, characterized in that, The slag removal device further comprises an oil discharge pipe; the oil discharge pipe is communicated with the bottom end of the overflow box and is used for discharging the oil liquid in the overflow box.

3. The slag removal device for oily sewage with a backwashing type according to claim 1, characterized in that The inlet device comprises a water pump, an inlet pipe and an electric valve I; one end of the inlet pipe is communicated with the box body, and the other end of the inlet pipe is communicated with the water pump; the end of the inlet pipe close to the box body is located below the filter screen and higher than the bottom end of the lower weir plate; the electric valve I is installed on the inlet pipe and is used for controlling the on-off state of the inlet pipe.

4. The slag removal device for oily sewage with a backwashing type according to claim 3, characterized in that, The slag removal device further comprises a heating device, and the heating device is installed at the end of the inlet pipe close to the box body; the heating device is an infrared heater or a carbon fiber heater.

5. The slag removal device for oily sewage with a backwashing type according to claim 3, characterized in that, The slag removal device further comprises an oil suction device, and the oil suction device comprises an oil pump, an oil suction pipe and an electric valve II; one end of the oil suction pipe is communicated with the box body, and the other end of the oil suction pipe is communicated with the oil pump; the end of the oil suction pipe close to the box body is higher than the end of the inlet pipe close to the box body; the electric valve II is installed on the oil suction pipe and is used for controlling the on-off state of the oil suction pipe.

6. The slag removal device for oily sewage with a backwashing type according to claim 1, characterized in that, The discharge device comprises a sludge pump, a drain pipe and an electric valve III; one end of the drain pipe is communicated with the bottom of the box body, and the other end of the drain pipe is communicated with the sludge pump; the electric valve III is installed on the drain pipe and is used for controlling the on-off state of the drain pipe.

7. The slag removal device for oily sewage with a backwashing type according to claim 4, characterized in that, The slag removal device further includes a flow meter, a temperature sensor, a liquid level gauge, an oil content detector, and a controller; the flow meter is installed on the water inlet device for measuring the water inlet rate v of the water inlet device in real time; the temperature sensor is installed inside the water inlet device for measuring the average temperature T of the oily sewage at the water outlet end of the water inlet device; the liquid level gauge is installed inside the box for measuring the depth h of the oily sewage in the box; the oil content detector is installed on the box for detecting the oil content ω1 of the oily sewage at the upper limit and the oil content ω2 of the oily sewage at the lower limit; the upper limit is located between the lower weir plate and the inner wall of the box, and the lower limit is not higher than the filter screen. The controller is used for: First, controlling the water inlet device to inlet water at the maximum power; at the same time, querying the heating power P in a conversion table according to the water inlet rate v, and then heating the oily sewage according to the heating power P so that the average temperature T is within a preset temperature range; the conversion table represents the mapping relationship between the water inlet rate v and the heating power P. Second, judging whether the depth h reaches a preset height h0, if so, controlling the water inlet device to inlet water at a preset water inlet rate v0. Third, judging whether the oil content ω2 is lower than a preset threshold ω0, if so, controlling to start the discharge device until the depth h is lower than a preset depth h2. IV. Determine whether the oil content ω1 is higher than a preset threshold ω h If so, drain the oil between the lower weir plate and the inner wall of the box body.

8. A backwashing slag removal method for oily sewage, which is applied to the backwashing slag removal device for oily sewage as described in claim 7, characterized in that The slag removal method includes the following steps: S1: Heating the oily sewage and then introducing it into the box; the specific process of the water inlet of the oily sewage is as follows: Determine whether the depth h of the oily wastewater in the box is lower than a preset depth h0. If so, the oily wastewater enters at the maximum inlet rate v max ; otherwise, the oily wastewater enters at a rate v0; query the corresponding heating power P in a pre-stored conversion table according to the inlet rate v of the oily wastewater, and then heat the oily wastewater according to the heating power P so that the average temperature T of the oily wastewater is within a preset temperature range; the conversion table represents the mapping relationship between the inlet rate v and the heating power P; S2: Filtering the solid waste residue in the oily sewage. S3: Filtering the floating scum in the oily sewage. S4: Discharging the oil layer or the oil-water mixed layer formed after the oily sewage is stratified in the box. S5: Discharging the separated sludge; among them, the discharge condition of the sludge is that the oil content ω2 at the lower limit is lower than a preset threshold ω0.

9. The slag removal method for oily sewage by backwashing according to claim 8, characterized in that, In step S2, the solid waste residue is filtered by the following method: installing a filter screen in the box; the oily sewage enters from below the filter screen and then is discharged from the top of the box; the solid waste residue in the oily sewage is intercepted below the filter screen, and the solid waste residue is discharged through the sewage discharge device, and at the same time, the solid waste residue blocked on the filter screen is backwashed.

10. The slag removal method for oily sewage by backwashing according to claim 8, characterized in that, In step S3, the floating scum is filtered by the following method: setting the outlet of the box as a serrated structure, and the oily sewage flows out in all directions through the serrated structure, and the floating scum is intercepted in the box through the serrated structure.

Images