Plate type filtering method and system for rolling mill process oil

Abstract

The invention relates to a plate type filtering method and system for rolling mill process oil, sump oil from a rolling mill is divided into two parts, one part of sump oil and a filter aid are mixed according to the mass ratio of 1100 kg: 75 kg to form a mixture, and the filter aid comprises kieselguhr, activated clay as an auxiliary material, an antioxidant and cellulose; the method comprises the following steps: introducing a mixture into a filter to form a pre-coating layer in the filter; then, the other part of sump oil is continuously fed into the filter at the flow rate of 60 kg / s, the mixture is injected into the sump oil every 19-21 s, and the amount of the mixture injected each time is 1.6 kg; according to the method, the filtering period is prolonged to 64 h, the production efficiency is improved, the production cost and the hazardous waste treatment cost are reduced, meanwhile, the transmittance of the rolling oil is improved to 95% or above, and the oil product index is stable.

Description

Technical Field

[0001] The invention relates to the technical field of rolling waste oil filtration, in particular to a plate-type filtration method and system for process oil of an aluminum plate and strip rolling mill. Background Art

[0002] During the rolling process of aluminum strips, rolling oil is used to form an oil film on the surface of the rolled piece to reduce the friction coefficient and friction force on the contact arc surface of the deformation zone and ensure the stability of the rolling process. During this process, impurities such as aluminum powder, aluminum chips, and dust are continuously generated and enter the rolling oil, causing it to turn black and reduce its use effect. Therefore, the rolling oil after passing through the rolling mill becomes dirty oil. During the rolling process of aluminum strips, the cleanliness of the rolling oil is an important factor affecting the quality and production efficiency of the aluminum strips. Rolling oil with low cleanliness is easy to form extremely small micro-pits on the surface of the aluminum foil, affecting the surface quality of the aluminum foil. Therefore, it is necessary to filter the used rolling oil.

[0003] At present, rolling oil is generally filtered using plate filters and filter paper as media. Specifically, filter aids are first added to the mixing box and mixed evenly with the dirty oil, and the mixture is pumped into the filter box for pre-coating to form a pre-coating layer on the filter paper; after the rolling mill is running, the dirty oil and the filter aids are mixed evenly in the mixing box, and then pumped into the filter box for filtration; when the liquid level of the mixture in the mixing box drops to the preset liquid level, dirty oil and filter aids are added to the mixing box again for stirring, and the evenly mixed mixture is continuously pumped into the filter box for filtration. The above method is used to filter the rolling oil to achieve the recycling of the rolling oil.

[0004] However, when filtering the rolling oil of the rough rolling mill, due to the large amount of filtered oil, a lot of aluminum powder and aluminum chips, and a lot of dust, the filtration cycle is 18-24 hours. After each filtration cycle, the machine needs to be shut down for 1 hour to clean the filter and replace the filter paper, which seriously affects the production efficiency of the rolling mill. At the same time, the short filtration cycle results in a large consumption of filtration materials, and high production costs and hazardous waste treatment costs. Summary of the invention

[0005] In order to solve the problem of short filtration cycle in the prior art, the present invention provides a plate filtration method and system for rolling mill process oil. The filtration cycle is extended to 64 hours, which improves production efficiency, reduces production cost and hazardous waste treatment cost. At the same time, the transmittance of rolling oil is increased to more than 95%, and the oil quality indicators are stable.

[0006] In order to achieve the above-mentioned purpose, the specific scheme adopted by the present invention is: a plate filtering method for rolling mill process oil, characterized in that: the dirty oil from the rolling mill is divided into two parts, one part of the dirty oil is mixed with a filter aid at a mass ratio of 1100kg:75kg to form a mixture, and the filter aid includes diatomaceous earth, activated clay, antioxidant and cellulose; the mixture is first introduced into the filter to form a pre-coating layer in the filter; then, another part of the dirty oil is continuously fed into the filter at a flow rate of 58-62kg / s, and the mixture is injected into the dirty oil every 19-21s, and the amount of the mixture injected each time is 1.4-1.7kg; finally, clean oil is obtained.

[0007] As an optimization scheme for the plate filtration method of the above-mentioned rolling mill process oil, the mass ratio of diatomaceous earth, activated clay and cellulose is 60:15:1.

[0008] As another optimization scheme of the above-mentioned plate filtering method for rolling mill process oil: the thickness of the pre-coating layer is 2 mm.

[0009] As another optimization scheme of the above-mentioned plate filtering method for rolling mill process oil: the flow rate of dirty oil introduced into the filter is 60 kg / s.

[0010] As another optimization scheme of the plate filtering method for the above rolling mill process oil: the mixture is injected into the dirty oil every 20 seconds, and the amount of the mixture injected each time is 1.6 kg.

[0011] A plate filter system for rolling mill process oil includes a mixing box and a filter, wherein the outlet of the filter is connected to a clean oil tank via an oil outlet pipeline, and the inlet of the filter is connected to a dirty oil tank via an oil inlet pipeline. The system is characterized in that a first pipeline for introducing dirty oil into the mixing box and a second pipeline for introducing a filter aid into the mixing box are provided, and the outlet of the mixing box is connected to the oil inlet pipeline via a third pipeline, so that the mixture in the mixing box enters the oil inlet pipeline and mixes with the dirty oil in the oil inlet pipeline.

[0012] As an optimization solution for the plate filter system of the above rolling mill process oil: a first valve is arranged on the third pipeline.

[0013] As another optimization solution of the plate filter system for the rolling mill process oil, the inlet of the dirty oil tank is connected with a dirty oil pipeline for introducing dirty oil into the inside thereof.

[0014] As another optimization scheme of the plate filter system for the above-mentioned rolling mill process oil: one end of the first pipeline away from the mixing tank is connected to the dirty oil pipeline.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention provides a plate filtering method for mill process oil, firstly, dirty oil and filter aid are introduced into a stirring box and mixed evenly to obtain a mixture, wherein the filter aid is mainly diatomaceous earth, supplemented by activated white clay, and a proportion mixture of antioxidant and cellulose is specially added; the mixture is introduced into a filter to form a pre-coat layer in the filter, the mill is turned on, the dirty oil in the dirty oil tank is continuously introduced into the filter box, the stirring box intermittently introduces the mixture into the oil inlet pipeline, the mixture is mixed with the dirty oil and then enters the filter box, and the filtered clean oil enters the clean oil tank through the oil outlet pipeline. By adopting the above method, the filtration cycle is extended to 64h, the production efficiency is improved, the production cost and the hazardous waste treatment cost are reduced, and at the same time, the permeability of the rolling oil is increased to more than 95%, and the oil product index is stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the present invention;

[0018] Figure numerals: 1. filter, 101. oil outlet pipeline, 102. oil inlet pipeline, 2. dirty oil tank, 201. dirty oil pipeline, 3. mixing tank, 301. first pipeline, 302. second valve, 303. third pipeline, 304. first valve, 4. clean oil tank, 5. rolling mill, 6. return oil tank. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further elaborated in detail below in conjunction with specific embodiments. The parts that are not described and disclosed in detail in the following embodiments of the present invention should be understood as the existing technology known or should be known to those skilled in the art, such as how the filter 1 filters, how to evenly mix the dirty oil and the filter aid in the mixing box 3, etc.

[0020] A plate filtering method for rolling mill process oil, the dirty oil from the rolling mill 5 is divided into two parts, one part of the dirty oil is mixed with a filter aid at a mass ratio of 1100kg:75kg to form a mixture, the filter aid includes diatomaceous earth, activated clay, antioxidant and cellulose; the mixture is first introduced into the filter 1 to form a pre-coat layer in the filter 1; then, another part of the dirty oil is continuously fed into the filter 1 at a flow rate of 58-62kg / s, and the mixture is injected into the dirty oil every 19-21s, and the amount of the mixture injected each time is 1.4-1.7kg; finally, clean oil is obtained. The present invention adopts a filter aid and a method of intermittently injecting the mixture into the dirty oil, and the filtration cycle is extended from the original 24h to 64h, which is increased by 167%; the continuous production of the rolling mill 5 is ensured, and the production efficiency is improved; the consumption of the filter aid is reduced, and the production cost and the hazardous waste treatment cost are reduced; at the same time, the permeability of the rolling oil is increased to more than 95%, and the oil product index is stable.

[0021] Example 1

[0022] A plate filtering method for rolling mill process oil, comprising the following specific steps:

[0023] Before the rolling mill 5 is operated, the dirty oil and the filter aid are mixed in a mass ratio of 1100kg:75kg to form a mixture, wherein the filter aid includes diatomite, activated clay, antioxidant and cellulose. The diatomite is composed of two different properties, RSA7 soil and TS20 soil, wherein the RSA7 soil has a permeability of 0.31, a water soluble matter of 0.36%, a hydrochloric acid soluble matter of 2.08%, a tap density of 0.50 g / cm3, an iron oxide content of 1.38% and an aluminum oxide content of 2.06%; the TS20 soil has a permeability of 0.21, a water soluble matter of 0.19%, a hydrochloric acid soluble matter of 2.02%, a tap density of 0.49 g / cm3, an iron oxide content of 1.32% and an aluminum oxide content of 2.06%. Antioxidants are also added to the filter aid to prevent the formation of oxides, promote the decomposition of peroxides, inhibit the catalytic effect of metal ions on oil oxidation, reduce the formation of colloids during the oxidation process, have good solubility in mineral oils, and have no tendency to crystallize at low temperatures.

[0024] First, the mixture is introduced into the filter 1 to form a pre-coat layer with a thickness of 2 mm in the filter 1, so as to ensure the normal operation of the filter 1 and extend the filtering period.

[0025] The rolling mill 5 starts to run, and the dirty oil produced by the rolling mill 5 is continuously passed into the filter 1 at a flow rate of 60kg / s, and the mixture is injected into the dirty oil every 20 seconds. The amount of the mixture injected each time is 1.6kg. The dirty oil becomes clean oil after being filtered by the filter 1.

[0026] Example 2

[0027] A plate filtering method for rolling mill process oil, comprising the following specific steps:

[0028] Before the rolling mill 5 is operated, the dirty oil and the filter aid are mixed in a mass ratio of 1100kg:75kg to form a mixture, wherein the filter aid includes diatomite, activated clay, antioxidant and cellulose. The diatomite is composed of two different properties, RSA7 soil and TS20 soil, wherein the RSA7 soil has a permeability of 0.31, a water soluble matter of 0.36%, a hydrochloric acid soluble matter of 2.08%, a tap density of 0.50 g / cm3, an iron oxide content of 1.38% and an aluminum oxide content of 2.06%; the TS20 soil has a permeability of 0.21, a water soluble matter of 0.19%, a hydrochloric acid soluble matter of 2.02%, a tap density of 0.49 g / cm3, an iron oxide content of 1.32% and an aluminum oxide content of 2.06%. Antioxidants are also added to the filter aid to prevent the formation of oxides, promote the decomposition of peroxides, inhibit the catalytic effect of metal ions on oil oxidation, reduce the formation of colloids during the oxidation process, have good solubility in mineral oils, and have no tendency to crystallize at low temperatures.

[0029] First, the mixture is introduced into the filter 1 to form a pre-coat layer with a thickness of 2 mm in the filter 1, so as to ensure the normal operation of the filter 1 and extend the filtering period.

[0030] The rolling mill 5 starts to run, and the dirty oil produced by the rolling mill 5 is continuously passed into the filter 1 at a flow rate of 58 kg / s, and the mixture is injected into the dirty oil every 21 seconds. The amount of the mixture injected each time is 1.4 kg. The dirty oil becomes clean oil after being filtered by the filter 1.

[0031] Example 3

[0032] A plate filtering method for rolling mill process oil, comprising the following specific steps:

[0033] Before the rolling mill 5 is operated, the dirty oil and the filter aid are mixed in a mass ratio of 1100kg:75kg to form a mixture, wherein the filter aid includes diatomite, activated clay, antioxidant and cellulose. The diatomite is composed of two different properties, RSA7 soil and TS20 soil, wherein the RSA7 soil has a permeability of 0.31, a water soluble matter of 0.36%, a hydrochloric acid soluble matter of 2.08%, a tap density of 0.50 g / cm3, an iron oxide content of 1.38% and an aluminum oxide content of 2.06%; the TS20 soil has a permeability of 0.21, a water soluble matter of 0.19%, a hydrochloric acid soluble matter of 2.02%, a tap density of 0.49 g / cm3, an iron oxide content of 1.32% and an aluminum oxide content of 2.06%. Antioxidants are also added to the filter aid to prevent the formation of oxides, promote the decomposition of peroxides, inhibit the catalytic effect of metal ions on oil oxidation, reduce the formation of colloids during the oxidation process, have good solubility in mineral oils, and have no tendency to crystallize at low temperatures.

[0034] First, the mixture is introduced into the filter 1 to form a pre-coat layer with a thickness of 2 mm in the filter 1, so as to ensure the normal operation of the filter 1 and extend the filtering period.

[0035] The rolling mill 5 starts to run, and the dirty oil produced by the rolling mill 5 is continuously passed into the filter 1 at a flow rate of 62 kg / s, and the mixture is injected into the dirty oil every 19 seconds. The amount of the mixture injected each time is 1.7 kg. The dirty oil becomes clean oil after being filtered by the filter 1.

[0036] The above is a basic implementation of the present invention, and further improvements, optimizations and limitations can be made on the above basis to obtain the following embodiments:

[0037] Example 4

[0038] A plate filter system for rolling mill process oil, such as Figure 1As shown, the filtering system includes a mixing tank 3 and a filter 1. The outlet of the filter 1 is connected to the clean oil tank 4 through an oil outlet pipeline 101. The clean oil tank 4 is connected to the rolling mill 5. The clean oil in the clean oil tank 4 enters the rolling mill 5 to form an oil film on the surface of the rolled piece. The clean oil passing through the rolling mill 5 becomes dirty oil, and the dirty oil enters the return oil tank 6. The inlet of the filter 1 is connected to the dirty oil tank 2 through an oil inlet pipeline 102. One end of the oil inlet pipeline 102 is connected to the inlet of the filter 1, and the other end of the oil inlet pipeline 102 is connected to the outlet of the dirty oil tank 2. The inlet of the dirty oil tank 2 is connected to a dirty oil pipeline 201 for introducing dirty oil into the interior thereof. In this embodiment, one end of the dirty oil pipeline 201 is connected to the return oil tank 6, and the other end of the dirty oil pipeline 201 is connected to the dirty oil tank 2, that is, the dirty oil in the return oil tank 6 enters the dirty oil tank 2 through the dirty oil pipeline 201. Therefore, the dirty oil generated by the rolling mill 5 first enters the oil return tank 6 , then enters the dirty oil tank 2 through the dirty oil pipeline 201 , and finally enters the filter 1 through the oil inlet pipeline 102 .

[0039] The mixing box 3 is provided with a first pipeline 301 for introducing dirty oil into the mixing box 3 and a second pipeline for introducing filter aids into the mixing box 3. In this embodiment, one end of the first pipeline 301 is connected to the mixing box 3, and the other end of the first pipeline 301 is connected to the dirty oil pipeline 201, and a second valve 302 is installed on the first pipeline 301. The second valve 302 is opened to allow a part of the dirty oil in the dirty oil pipeline 201 to enter the mixing box 3 to form a mixture with the filter aid, and the second valve 302 is closed to cut off the first pipeline 301, so that the dirty oil in the dirty oil pipeline 201 cannot enter the mixing box 3.

[0040] The outlet of the mixing box 3 is connected to the oil inlet pipeline 102 through the third pipeline 303, so that the mixture in the mixing box 3 intermittently enters the oil inlet pipeline 102 and mixes with the dirty oil in the oil inlet pipeline 102, and the mixture and the dirty oil are mixed and enter the filter 1. The third pipeline 303 is provided with a first valve 304. The first valve 304 is opened to allow the mixture to enter the oil inlet pipeline 102 through the third pipeline 303, and the first valve 304 is closed to cut off the second pipeline, so that the mixture cannot enter the oil inlet pipeline 102, that is, only the dirty oil is introduced into the filter 1.

[0041] The operation process of the filtration system includes the following steps:

[0042] Before the rolling mill 5 is operated, filter aids are added into the mixing box 3 and filled with dirty oil. The mass ratio of filter aids to dirty oil is 75kg:1100kg. The dirty oil and filter aids are evenly mixed in the mixing box 3 to obtain a mixture.

[0043] First, the first valve 304 is opened to allow the mixture in the mixing box 3 to flow into the oil inlet pipeline 102 through the third pipeline 303 and finally enter the filter 1 to form a pre-coat layer with a thickness of 2 mm in the filter 1 .

[0044] The rolling mill 5 is running. At this time, the first valve 304 and the second valve 302 are in a closed state. The dirty oil generated by the rolling mill 5 flows through the return oil tank 6 and the dirty oil tank 2 in turn, and then enters the filter 1 through the oil inlet pipeline 102 at a flow rate of 60 kg / s. After the dirty oil is introduced into the filter 1 for 20 seconds, the first valve 304 is opened, and a mixture of dirty oil and filter aid is injected into the oil inlet pipeline 102, and then the first valve 304 is closed. That is, 1.6 kg of the mixture is injected into the oil inlet pipeline 102 every 20 seconds, so that the dirty oil is mixed with the mixture and then enters the filter 1.

[0045] When the liquid level in the mixing tank 3 is lower than the preset liquid level, filter aid is added into the mixing tank 3, and the second valve 302 is opened at the same time, so that part of the dirty oil in the dirty oil pipeline 201 fills the mixing tank 3, and then the second valve 302 is closed to make the dirty oil and the filter aid be evenly mixed in the mixing tank 3 to form a mixture.

[0046] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A plate filtering method for rolling mill process oil, characterized in that: The dirty oil from the rolling mill is divided into two parts, one part of the dirty oil is mixed with a filter aid at a mass ratio of 1100kg:75kg to form a mixture, the filter aid comprising diatomaceous earth, activated clay, an antioxidant and cellulose; the mixture is first introduced into a filter (1) to form a pre-coat layer in the filter (1); then, another part of the dirty oil is continuously introduced into the filter (1) at a flow rate of 58-62kg / s, and the mixture is injected into the dirty oil every 19-21s, and the amount of the mixture injected each time is 1.4-1.7kg; finally, clean oil is obtained.

2. A plate-type filtering method for rolling mill process oil according to claim 1, characterized in that: The mass ratio of diatomaceous earth, activated clay and cellulose is 60:15:

1.

3. A plate-type filtering method for rolling mill process oil according to claim 1, characterized in that: The thickness of the pre-coating layer is 2 mm.

4. A plate-type filtering method for rolling mill process oil according to claim 1, characterized in that: The flow rate of dirty oil into the filter is 60kg / s.

5. A plate-type filtering method for rolling mill process oil according to claim 1, characterized in that: The mixture was injected into the waste oil every 20 seconds, and the amount of the mixture injected each time was 1.6 kg.

6. A plate filter system for rolling mill process oil, comprising a stirring tank (3) and a filter (1), wherein the outlet of the filter (1) is connected to a clean oil tank (4) via an oil outlet pipeline (101), and the inlet of the filter (1) is connected to a dirty oil tank (2) via an oil inlet pipeline (102), characterized in that: The mixing box (3) is provided with a first pipeline (301) for introducing dirty oil into the interior thereof and a second pipeline for introducing a filter aid into the interior thereof. The outlet of the mixing box (3) is connected to the oil inlet pipeline (102) via a third pipeline (303), so that the mixture in the mixing box (3) enters the oil inlet pipeline (102) and mixes with the dirty oil in the oil inlet pipeline (102).

7. A plate type filter system for rolling mill process oil according to claim 6, characterized in that: The third pipeline (303) is provided with a first valve.

8. A plate type filter system for rolling mill process oil according to claim 6, characterized in that: The inlet of the dirty oil tank (2) is connected to a dirty oil pipeline (201) for introducing dirty oil into the interior thereof.

9. A plate type filter system for rolling mill process oil according to claim 8, characterized in that: One end of the first pipeline (301) away from the mixing tank (3) is connected to the dirty oil pipeline (201).

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