Stainless steel rolling oil-sludge separation system and use method thereof

Abstract

The invention discloses a stainless steel rolling oil-sludge separation system and a use method thereof. The separation system comprises a buffer oil tank, a deposition tank group, a sludge tank, an oil-sludge storage tank, a stirrer and a centrifugal machine, an oil inlet of the deposition tank group is communicated with an oil outlet of the buffer oil tank, a sewage draining exit of the deposition tank group is used for delivering the oil sludge, and an oil outlet of the deposition tank group is communicated with the oil inlet of the buffer oil tank and is used for delivering oil; an oil inlet of the mud tank is communicated with a drain outlet of the deposition box group; an oil inlet of the oil sludge storage box is communicated with a drain outlet of the sludge tank and is used for storing oil sludge discharged by the sludge tank; the stirrer is arranged in the oil sludge storage box; an oil inlet of the centrifugal machine is communicated with an oil outlet of the oil sludge storage box, and an oil outlet of the centrifugal machine is communicated with an oil inlet of the oil sludge storage box and used for centrifugally separating the oil sludge; sludge separated by the centrifugal machine is discharged from a drain outlet of the centrifugal machine. Compared with the prior art, the structure is simple, and the oil content of separated oil residues is low.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of stainless steel cold rolling, in particular to a stainless steel rolling oil sludge separation system and a use method thereof. BACKGROUND

[0002] In the production process of cold-rolled stainless steel strip, mineral oil is generally used as the cooling and lubricating medium due to the high requirements for surface quality. While playing the roles of cooling and lubrication, the rolling oil will take away the metal debris generated on the surface of the stainless steel. To realize the recycling of the rolling oil, it is usually required to pass through primary and secondary filters in sequence and perform backwashing operation on the filter core. The oil liquid after backwashing enters an intermediate settling oil tank, and solid impurities are separated by means of three-stage gravity natural sedimentation; the solid-liquid mixture (sludge) formed by sedimentation is discharged from the bottom valve and pumped to a sludge tank for secondary gravity sedimentation. Finally, the sludge discharged from the bottom of the sludge tank is treated as solid waste.

[0003] Currently, there are some patented technologies in this field related to rolling oil filtration or sludge treatment, such as using centrifugal separation, magnetic adsorption or precision filtration to improve the cleanliness of the oil. However, most of the existing technologies still rely on gravity natural sedimentation as the core separation method, or although auxiliary treatment measures are introduced, the problems of low sedimentation efficiency and high oil content in the sludge cannot be effectively solved.

[0004] The existing process has the following outstanding problems: the separation efficiency of gravity natural sedimentation is low, and the discharge speed of solid particles is lower than the new speed, resulting in continuous accumulation of sludge in the intermediate oil tank and the sludge tank, which requires manual cleaning of the sludge adhered to the tank wall and the tank wall every half year, increasing the maintenance cost and downtime. In addition, in order to maintain the fluidity of the sludge, the oil content of the sludge discharged from the bottom valve of the sludge tank (3) is usually not less than 50% (measured by 350℃ high-temperature burning loss method, reduced weight / weight before burning). As solid waste treatment, high-oil sludge not only wastes rolling oil, but also significantly increases the treatment cost of solid waste. Therefore, it is necessary to improve the existing separation technology. SUMMARY

[0005] The first technical problem to be solved by the present application is to provide a stainless steel rolling oil sludge separation system.

[0006] The second technical problem to be solved by the present application is to provide a use method of the stainless steel rolling oil sludge separation system.

[0007] The technical solution adopted by the present application to solve the above-mentioned first technical problem is: a stainless steel rolling oil sludge separation system, comprising

[0008] a buffer tank for sedimentation of the sludge, the oil inlet being in communication with an external filter tank;

[0009] A sedimentation tank assembly, with its inlet connected to the outlet of a buffer tank, is used for secondary sedimentation of sludge from the buffer tank. The sludge is discharged from the sedimentation tank assembly's drain outlet, and the outlet is connected to the inlet of the buffer tank for discharging oil.

[0010] The sludge tank, with its oil inlet connected to the sludge outlet of the sedimentation tank group, is used to perform three-stage sedimentation of the oil sludge from the sedimentation tank group.

[0011] Its characteristic is that it also includes:

[0012] The oil sludge storage tank has an oil inlet connected to the drain outlet of the sludge tank and is used to store the oil sludge discharged from the sludge tank.

[0013] A mixer, located inside a sludge storage tank, is used to mix the sludge in the tank; and,

[0014] The centrifuge has an oil inlet connected to the oil outlet of the sludge storage tank, and the oil outlet is connected to the oil inlet of the sludge storage tank and is used to centrifuge and separate the sludge; the sludge separated by the centrifuge is discharged from the centrifuge's drain outlet.

[0015] Preferably, a clean oil pump is provided between the centrifuge and the sludge storage tank.

[0016] To facilitate the separation of oil sludge, preferably, the sedimentation tank assembly is provided with multiple partitions, which divide the sedimentation tank into multiple sedimentation chambers. Adjacent sedimentation chambers are connected by an overflow gap. There are multiple sedimentation chambers, which are arranged sequentially.

[0017] Preferably, along the overflow direction of the oil in the sedimentation tank group, the last sedimentation chamber has an oil outlet, and the oil outlet of the sedimentation chamber is connected to the oil inlet of the buffer tank.

[0018] Preferably, a secondary filter pump is provided between the oil outlet of the sedimentation chamber and the oil inlet of the buffer oil tank.

[0019] To increase the discharge of sludge from the sedimentation chamber and reduce the residence time of sludge in the sedimentation chamber, thereby avoiding the residue of sludge on the walls of the sedimentation chamber, preferably, each sedimentation chamber is provided with a drain outlet at the bottom, and the drain outlet of the sedimentation chamber is connected to the oil inlet of the sludge tank; a sludge pump is provided between the drain outlet of the sedimentation chamber and the oil inlet of the sludge tank.

[0020] To further separate the oil sludge, preferably, a secondary filter tank is also included between the buffer tank and the sludge tank. The secondary filter tank is equipped with a filter element, and the drain outlet of the secondary filter tank is connected to the sludge tank.

[0021] In order to enable the self-separation system to recover clean oil, preferably, a dirty oil tank is also included, and the oil outlet of the secondary filter tank is connected to the dirty oil tank.

[0022] Preferably, a drain pump is provided between the sludge storage tank and the buffer oil tank, and the drain pump is used to transport the oil from the top of the sludge storage tank to the buffer oil tank.

[0023] The technical solution adopted by the present invention to solve the second technical problem mentioned above is: a method of using the aforementioned stainless steel rolling oil-sludge separation system, characterized by including the following steps:

[0024] ① The oil sludge mixture is placed in the buffer tank. After the oil sludge mixture settles, the upper layer of sludge overflows into the sedimentation tank group. The sludge that settles naturally by gravity in the sedimentation tank group is sent to the oil sludge storage tank through the sewage outlet of the sedimentation tank group.

[0025] ②Start the mixer to evenly mix the sludge in the sludge storage tank;

[0026] ③ Start the centrifuge and begin the liquid separation mode at 3000 rpm and a centrifugal force of 1650-1750G; stop the centrifuge after separation is complete.

[0027] ④ After the centrifuge has been stationary for 80-100 seconds, start the centrifuge to begin dehydration; after the centrifuge has been dehydrating for 200-300 seconds, the centrifuge will stop again.

[0028] ⑤ After the centrifuge has been stationary for 100-150 seconds, turn on the centrifuge, scrape off the sludge 7-12 times with a scraper, and then turn off the centrifuge.

[0029] ⑥ Calculate the time taken for steps ③-⑤. If the time taken for steps ③-⑤ is less than 8 hours, or if the amount of sludge scraped off by the centrifuge is greater than or equal to 1 kg, then repeat steps ③-⑤.

[0030] If the time taken for steps ③-⑤ is ≥8 hours, or the amount of sludge scraped out by the centrifuge is <1KG, then stop the mixer and enter the static liquid mode.

[0031] ⑦ The settling time in static mode is 4-6 hours. After settling, the upper layer of oil is removed from the sludge storage tank.

[0032] Compared with the prior art, the advantages of the present invention are as follows: firstly, the oil sludge is separated by multiple sedimentation through a settling tank group, a buffer oil tank and a sludge tank, and then the sludge oil sent from the sludge tank is separated into solid and liquid by a centrifuge. The oil cleaning is improved, the filtration burden of the secondary filter element is reduced, the service life of the filter element is extended, and the oil content of the sludge discharged from the centrifuge is greatly reduced to ≤10%. The process is simple, the structure is simple, it is easy to operate and has low operating costs. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of an embodiment. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0035] Example

[0036] like Figure 1 The image shows a preferred embodiment of the present invention. The stainless steel rolling oil sludge separation system includes a buffer tank 1, a sedimentation tank group 2, a sludge tank 3, an oil sludge storage tank 4, a mixer 5, a centrifuge 6, a clean oil pump 7, a secondary filter pump 8, a sludge pump 9, a secondary filter tank 10, a dirty oil tank 11, and a drain pump 12.

[0037] The buffer tank 1 is used for sedimentation of sludge, and its inlet is connected to an external filter tank.

[0038] The inlet of sedimentation tank group 2 is connected to the outlet of buffer tank 1 for secondary sedimentation of sludge from buffer tank 1. The drain outlet of sedimentation tank group 2 is used to discharge sludge, and the outlet is connected to the inlet of buffer tank 1 for discharging oil. Sedimentation tank group 2 is equipped with multiple partitions 21, which divide the sedimentation tank into multiple sedimentation chambers 22. Adjacent sedimentation chambers 22 are connected by overflow gaps. There are multiple sedimentation chambers 22, arranged sequentially. Along the overflow direction of oil in sedimentation tank group 2, the last sedimentation chamber 22 has an outlet, which is connected to the inlet of buffer tank 1. Each sedimentation chamber 22 has a drain outlet at its bottom, which is connected to the inlet of sludge tank 3.

[0039] The oil inlet of sludge tank 3 is connected to the sewage outlet of sedimentation tank group 2, which is used to perform three sedimentation of oil sludge from sedimentation tank group 2.

[0040] The oil inlet of the sludge storage tank 4 is connected to the drain outlet of the sludge tank 3, and is used to store the oil sludge discharged from the sludge tank 3.

[0041] A mixer 5 is located inside the sludge storage tank 4 and is used to mix the sludge in the sludge storage tank 4; and,

[0042] The oil inlet of centrifuge 6 is connected to the oil outlet of sludge storage tank 4, and the oil outlet is connected to the oil inlet of sludge storage tank 4 and is used to centrifuge and separate the sludge; the sludge separated by centrifuge 6 is discharged from the drain outlet of centrifuge 6.

[0043] The clean oil pump 7 is located between the centrifuge 6 and the sludge storage tank 4.

[0044] The secondary filter pump 8 is located between the oil outlet of the sedimentation chamber 22 and the oil inlet of the buffer oil tank 1.

[0045] The sludge pump 9 is located between the drain outlet of the sedimentation chamber 22 and the oil inlet of the sludge tank 3.

[0046] A secondary filter tank 10 is located between the buffer oil tank 1 and the sludge tank 3. The secondary filter tank 10 contains a filter element 101, and its drain outlet is connected to the sludge tank 3. The oil outlet of the secondary filter tank 10 is connected to the dirty oil tank 11. Users can remove the separated clean oil from the dirty oil tank 11.

[0047] A drain pump 12 is provided between the sludge storage tank 4 and the buffer oil tank 1. The drain pump 12 is used to transport the oil from the top of the sludge storage tank 4 to the buffer oil tank 1.

[0048] The usage method of the stainless steel rolling oil sludge separation system includes the following steps:

[0049] ①The sludge that settles naturally by gravity in sedimentation tank group 2 is pumped by sludge pump 9 from the sewage outlet of sedimentation tank group 2 to sludge storage tank 4;

[0050] ② Start the mixer 5 to uniformly mix the oil sludge in the oil sludge storage tank 4;

[0051] ③ When the sludge storage tank 4 reaches the first liquid level, turn off the sludge pump 9 and start the clean oil pump 7 and centrifuge 6. The centrifuge 6 starts the clean liquid separation mode at 3000 rpm and 1650-1750G centrifugal force. After the separation is completed, stop the centrifuge 6. When the clean oil separation time reaches 7-15 minutes, stop the clean oil pump 7 and centrifuge 6, and the centrifuge drum of centrifuge 6 stops.

[0052] ④ After centrifuge 6 has been stationary for 80-100 seconds, start centrifuge 6 to begin dehydration; after centrifuge 6 has been dehydrating for 200-300 seconds, centrifuge 6 will stop again.

[0053] ⑤ After centrifuge 6 has been stationary for 100-150 seconds, turn on centrifuge 6, scrape off the sludge with a scraper 7-12 times, and then turn off centrifuge (6);

[0054] ⑥ Calculate the time taken in steps ③-⑤, and weigh the sludge scraped out by centrifuge 6 using weighing cart 13.

[0055] If the time taken for steps ③-⑤ is less than 8 hours, or the amount of sludge scraped out by centrifuge 6 is greater than or equal to 1 kg, then repeat steps ③-⑤.

[0056] If the time taken for steps ③-⑤ is ≥8 hours and the amount of sludge scraped out by centrifuge 6 is <1KG, then stop mixer 5 and enter static liquid mode.

[0057] ⑦ The settling time in static liquid mode is 4-6 hours. After settling, the upper layer of oil is removed from the sludge storage tank 4, and the drain pump 12 is started to send the oil from the sludge storage tank 4 to the buffer oil tank 1. When the sludge storage tank 4 reaches the second liquid level, the drain pump 12 is stopped. Users can set the first and second liquid levels as needed, with the first liquid level being higher than the second liquid level. The oil content of the sludge discharged from the centrifuge 6 cylinder wall is significantly reduced, reaching ≤10% (incineration at 350℃ high temperature: weight reduction / weight before incineration), thus reducing the consumption of rolling oil.

[0058] Comparative Example

[0059] The stainless steel rolling oil sludge separation system of this comparative example includes a buffer tank 1, a sedimentation tank group 2, a sludge tank 3, a secondary filter pump 8, a sludge pump 9, a secondary filter tank 10, and a dirty oil tank 11. The sludge separated in this comparative example has an oil content of approximately 50%.

Claims

1. A stainless steel rolling oil-sludge separation system, comprising: The buffer tank (1) is used to settle the sludge, and the oil inlet is connected to the external filter tank. The sedimentation tank assembly (2) has an oil inlet connected to the oil outlet of the buffer tank (1) for secondary sedimentation of sludge from the buffer tank (1). The sludge discharge port of the sedimentation tank assembly (2) is used to discharge the sludge, and the oil outlet is connected to the oil inlet of the buffer tank (1) for discharging oil. The sludge tank (3) has an oil inlet connected to the drain outlet of the sedimentation tank group (2) and is used to perform three sedimentation processes on the oil sludge from the sedimentation tank group (2). Its features are: Also includes The oil sludge storage tank (4) has an oil inlet connected to the drain outlet of the sludge tank (3) and is used to store the oil sludge discharged from the sludge tank (3). A mixer (5) is installed inside the sludge storage tank (4) and is used to mix the sludge in the sludge storage tank (4); and, The centrifuge (6) has an oil inlet connected to the oil outlet of the sludge storage tank (4), and the oil outlet is connected to the oil inlet of the sludge storage tank (4) and is used to centrifuge the sludge; the sludge separated by the centrifuge (6) is discharged from the drain outlet of the centrifuge (6).

2. The stainless steel rolling oil-sludge separation system according to claim 1, characterized in that: An oil purification pump (7) is provided between the centrifuge (6) and the sludge storage tank (4).

3. The stainless steel rolling oil-sludge separation system according to claim 1, characterized in that: The sedimentation tank assembly (2) is provided with multiple partitions (21), which divide the sedimentation tank assembly (2) into multiple sedimentation chambers (22). Two adjacent sedimentation chambers (22) are connected by an overflow gap. There are multiple sedimentation chambers (22), which are arranged in sequence.

4. The stainless steel rolling oil-sludge separation system according to claim 3, characterized in that: Along the overflow direction of the oil in the sedimentation tank group (2), the last sedimentation chamber (22) has an oil outlet, and the oil outlet of the sedimentation chamber (22) is connected to the oil inlet of the buffer tank (1).

5. The stainless steel rolling oil-sludge separation system according to claim 4, characterized in that: A secondary filter pump (8) is provided between the oil outlet of the sedimentation chamber (22) and the oil inlet of the buffer oil tank (1).

6. The stainless steel rolling oil-sludge separation system according to claim 3, characterized in that: Each of the sedimentation chambers (22) is provided with a drain outlet at the bottom, and the drain outlet of the sedimentation chamber (22) is connected to the oil inlet of the sludge tank (3); an oil pump (9) is provided between the drain outlet of the sedimentation chamber (22) and the oil inlet of the sludge tank (3).

7. The stainless steel rolling oil-sludge separation system according to claim 1, characterized in that: It also includes a secondary filter tank (10) located between the buffer tank (1) and the sludge tank (3), wherein the secondary filter tank (10) is provided with a filter element (101), and the drain outlet of the secondary filter tank (10) is connected to the sludge tank (3).

8. The stainless steel rolling oil-sludge separation system according to claim 7, characterized in that: It also includes a dirty oil tank (11), and the oil outlet of the secondary filter tank (10) is connected to the dirty oil tank (11).

9. The stainless steel rolling oil-sludge separation system according to claim 1, characterized in that: A drain pump (12) is provided between the sludge storage tank (4) and the buffer oil tank (1), and the drain pump (12) is used to transport the oil at the top of the sludge storage tank (4) to the buffer oil tank (1).

10. A method of using the stainless steel rolling oil-sludge separation system according to any one of claims 1-9, characterized in that: Includes the following steps: ①Put the oil sludge mixture into the buffer tank (1). After the oil sludge mixture settles, the upper layer of sludge overflows into the sedimentation tank group (2). The sludge that settles naturally by gravity in the sedimentation tank group (2) is sent to the oil sludge storage tank (4) through the sewage outlet of the sedimentation tank group (2). ② Start the mixer (5) to uniformly mix the oil sludge in the oil sludge storage tank (4); ③ Start the centrifuge (6). The centrifuge (6) starts the liquid separation mode at 3000 rpm and 1650-1750G centrifugal force. Stop the centrifuge (6) after the separation is completed. ④ After the centrifuge (6) has been stationary for 80-100 seconds, start the centrifuge (6) to begin dehydration; after the centrifuge (6) has been dehydrating for 200-300 seconds, the centrifuge (6) will be stationary again. ⑤ After the centrifuge (6) has been stationary for 100-150 seconds, turn on the centrifuge (6), scrape off the mud with a scraper 7-12 times, and then turn off the centrifuge (6); ⑥ Calculate the time taken for steps ③-⑤. If the time taken for steps ③-⑤ is < 8-16 hours, or if the amount of sludge scraped out by the centrifuge (6) is ≥ 1KG, then repeat steps ③-⑤. If the time taken for steps ③-⑤ is ≥8-16 hours and the amount of mud scraped out by the centrifuge (6) is <1KG, then stop the mixer (5) and enter the static liquid mode; ⑦ The static liquid time in static liquid mode is 4-6 hours. After static liquid is settled, the upper layer of oil is taken out from the sludge storage tank (4).

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