KR100923343B1 - Method for recycling oil used in vaccum pump and apparatus provided with therefor - Google Patents

Abstract

PURPOSE: A regeneration method and a reproducer of the vacuum pump oil are provided, which can maintain viscosity and color required to vacuum pump regeneration oil. CONSTITUTION: A regeneration method of vacuum pump oil is as follows. The waste oil is collected(S200). The activated coal powder is prepared(S230). The collected waste oil and the activated coal powder are mixed(S240). The stirring temperature of the mixture of the waste oil and activated coal powder is increased to the fixed temperature. The mixture of the waste oil and activated coal powder is agitated for a certain time(S250). The temperature of a mixture is dropped to the fixed temperature(S260). The mixture of which the temperature is descended is filtered through the filter.

Description

Method for recycling oil used in vacuum pump oil {Method for recycling oil used in vaccum pump and apparatus provided with therefor}

The present invention relates to a method for inexpensively and efficiently regenerating a vacuum pump oil used in semiconductor equipment and a regeneration device provided therefor, and more particularly, to impurities and moisture contained in waste oil used in a vacuum pump of semiconductor equipment. The present invention relates to a method for regenerating a vacuum pump oil and a regenerating device, which maintains the required viscosity and color in a vacuum pump regenerating oil and can be used even at high temperatures.

A variety of equipment is used in the semiconductor manufacturing process.

The equipment used in the semiconductor manufacturing process is provided with a chamber for performing each process. At this time, in order to proceed with the semiconductor manufacturing process, the chamber of each equipment should be made in a vacuum state, for which a vacuum pump is generally used.

The vacuum pump for vacuuming the chamber of semiconductor equipment is divided into a gear part and a sealing part, and oil is supplied to the gear part to drive the vacuum pump for vacuuming the chamber of the semiconductor equipment.

In general, fluorine-based lubricating oil is used as a vacuum pump oil in the semiconductor manufacturing process, and typically, Crytox oil or Pomblin oil is widely used.

By the way, the vacuum pump used to make the chamber of semiconductor equipment into a vacuum state is overhauled every 6 months to 1 year. At this time, consumables such as O-rings, bearings, and oils are discarded after replacement. Done. Therefore, vacuum pump oils such as Crytox oil or Fomblin oil also cannot be used permanently and are disposed of after 6 months to 1 year.

However, vacuum pump oils are classified as industrial waste and must be disposed of in accordance with certain environmental requirements. Therefore, the used vacuum pump oil has to go through a separate treatment process for waste disposal, and thus has a problem in that the processing cost becomes high.

Therefore, development of a technology for regenerating and using the vacuum pump oil used in the semiconductor process is required in the technical field to which the present invention belongs. In other words, if the vacuum pump oil used in the semiconductor process can be regenerated to produce the same oil as the new oil, the unit price of the vacuum pump oil can be lowered to less than half of the new oil price, thereby reducing costs and industrial waste. By recycling the waste, environmental pollution can be reduced.

Some vacuum pump oil regeneration techniques have been provided in this regard, but the prior art has had a problem that the viscosity decreases due to low boiling point oils decomposed during use in recycling waste oil. In addition, conventional regenerated vacuum pump oils often contain moisture, and there is a problem of corrosion of semiconductor equipment due to moisture in vacuum and high temperature environments. That is, in order to reuse the vacuum pump oil, the water must be completely removed and the viscosity must not be lowered even at a high temperature of 60 to 100 ° C. or more, but the conventionally regenerated vacuum pump oil did not meet the requirements of the regenerated vacuum pump oil. .

For example, in order to solve the above-mentioned viscosity problem, in the prior art, activated carbon and diatomaceous earth are used to filter foreign substances in the waste oil of the vacuum pump, but this method cannot completely remove foreign substances and moisture. There was a problem that it is difficult to fundamentally solve the problem of lowering the viscosity of the oil. In addition, there has been an attempt to prevent the deterioration of the viscosity of the regenerated vacuum pump oil by removing foreign matter in a vacuum distillation method, but this is not an industrially useful method.

Therefore, in the technical field to which the present invention belongs, it is inexpensively and efficiently regenerating the vacuum pump oil, while effectively removing impurities and moisture contained in the waste oil while maintaining the viscosity and color required for the vacuum pump oil and being able to use at high temperatures. It can be said that there is a need for a technology for regenerating vacuum pump oil.

Accordingly, the present inventors agitated the vacuum pump waste oil with the activated carbon powder, and confirmed that impurities and moisture were effectively removed according to the setting of the specific stirring temperature and the reaction time.

SUMMARY OF THE INVENTION The present invention has an object of solving the problems of the prior art as described above, and an object thereof is to provide a method and apparatus for inexpensively and efficiently regenerating vacuum pump oil.

More specifically, the present invention is to remove the impurities and water contained in the waste oil used in the vacuum pump of the semiconductor equipment, while maintaining the viscosity and color required for the vacuum pump regeneration oil and to be used at a high temperature vacuum pump oil It is an object of the present invention to provide a method and apparatus for reproducing.

The method for regenerating the vacuum pump oil of the present invention includes recovering waste oil used in a vacuum pump, preparing activated carbon, mixing and agitating the recovered waste oil and activated carbon, and Raising the stirring temperature of the mixture of activated carbon to a constant temperature, reacting the waste oil and the mixture of activated carbon with stirring for a predetermined time, lowering the temperature of the mixture to a constant temperature, and lowering the temperature Filtering the resultant mixture through a filter.

In one embodiment of the present invention, the activated carbon is preferably mixed in a proportion of 0.5% by weight based on the weight of the waste oil.

In addition, in the step of raising the stirring temperature of the mixture of the waste oil and activated carbon to a constant temperature, the elevated temperature may be about 80 ℃. In addition, in the step of lowering the temperature of the mixture to a constant temperature, the falling temperature may be about 40 ℃.

In a preferred embodiment of the present invention, the initial stirring speed of the mixture of the waste oil and activated carbon is about 600 to 700 rpm, the stirring speed of the mixture of the waste oil and activated carbon when the stirring temperature is raised to about 80 ℃ It is desirable to lower to about 400 rpm. After the stirring speed of the mixture of the waste oil and the activated carbon is lowered to about 400 rpm, it is preferable to stir and react the mixture for 4 hours based on the weight of the waste oil 100 kg.

In one preferred embodiment of the present invention, a plurality of filters are provided in multiple stages, and the filter of the last stage is preferably a membrane filter.

In the regeneration apparatus of the vacuum pump oil of the present invention, waste oil and activated carbon recovered and used in a vacuum pump are added and mixed, and the stirring temperature of the mixture of the waste oil and activated carbon is raised to a constant temperature and the mixture of the waste oil and activated carbon is It includes a stirrer for reacting while stirring for a predetermined time, and a plurality of filters in which the mixture of the waste oil and the activated carbon discharged through the flow pipe is introduced and filtered through the stirrer.

Preferably, the regeneration apparatus of the vacuum pump oil of one embodiment of the present invention further includes a pump provided in the flow passage and pumping the mixture from the stirrer to the filters.

 In the regeneration apparatus of the vacuum pump oil of an embodiment of the present invention, the filters are characterized in that the primary filter, the secondary filter, the tertiary filter and the fourth filter are sequentially positioned in multiple stages. The first to third filters are bag filters that sequentially remove impurities by size, and the fourth filters are membrane filters that finally remove impurities completely.

According to the present invention, it is possible to recycle vacuum pump oil inexpensively and efficiently, and in particular, it is possible to effectively remove impurities and moisture contained in waste oil used in vacuum pumps of semiconductor equipment, while maintaining the viscosity and color required for vacuum pump regeneration oil. It has the advantage of maintaining and enabling use at high temperatures.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings without limiting the present invention by way of example only.

The following examples of the present invention are not intended to limit or limit the scope of the present invention only to embody the present invention. From the detailed description and examples of the present invention, those skilled in the art to which the present invention pertains can easily be interpreted as belonging to the scope of the present invention.

1 is a block diagram of a vacuum pump oil regeneration device 100 of an embodiment of the present invention, Figure 2 is a method for regenerating the vacuum pump oil using the vacuum pump oil regeneration device 100 of Figure 1 for each step This is a flow chart to explain.

First, referring to the accompanying FIG. 1, the apparatus 100 for regenerating a vacuum pump oil according to an embodiment of the present invention includes an agitator 10 for removing moisture and impurities from waste oil using activated carbon powder, and a filter unit 30. ), A flow pipe 20 connecting the stirrer 10 and the filter unit 30 and flowing a mixture of waste oil and activated carbon powder from the stirrer 10 to the filter unit 30, and the flow tube And a feed pump 22 provided in the furnace 20 to pump the mixture from the stirrer 10 to the filter portion 30.

Waste oil and activated carbon powder used and recovered are added to the stirrer 10 to be mixed. The capacity of the stirrer 10 is approximately 1,000 L and is designed to be capable of treating 600 kg to 700 kg of waste oil. In order to stir the waste oil and the activated carbon powder, a stirring shaft (not shown) is provided in the agitator 10. An agitator motor 12 providing a rotational power of the stirring shaft may be installed at an upper end of the agitator 10. (See Figure 1). In addition, an upper side of the agitator 10 is installed in the exhaust pipe 14 for exhausting the volatile organic compound, and an exhaust fan 16 is installed at one end of the exhaust pipe 14 for efficient external discharge of the volatile organic compound. (See Figure 1).

The exhaust pipe 14 and the exhaust fan 16 serve to effectively remove volatile organic compounds generated when the waste oil and the activated carbon powder are introduced into the stirrer 10 and the internal temperature is increased to approximately 80 ° C. .

One side of the lower end of the stirrer 10 is connected to the flow passage 20, the mixture of the waste oil and activated carbon powder that is primarily processed in the stirrer 10 to the filter unit 30 through the flow passage (20) Inflow. The on-off valve 24 is provided in the flow line 20 near the stirrer 10. The on-off valve 24 is closed while the waste oil is being processed in the stirrer 10 and is opened when the treatment is completed to discharge the mixture of the treated waste oil and activated carbon powder through the flow passage 20. Then, the feed pump 22 provided in the flow passage 20 pumps the mixture of the waste oil and the activated carbon powder discharged by the opening and closing of the valve 24 to flow into the filter unit 30.

Meanwhile, a bypass pipe 26 is provided between the stirrer 10 and the filter part 30 to bypass the feed pump 22, so that even when the feed pump 22 is not driven by a power source, waste oil having a constant flow rate. And a mixture of activated carbon powder may be continuously introduced into the filter unit 30 in the stirrer (10). The bypass pipe 26 is provided with a separate opening and closing valve 28. This on-off valve 28 closes when the mixture of waste oil and activated carbon powder is forcedly flowed from the stirrer 10 to the filter part 30 by the feed pump 22, thereby rapidly flowing the mixture of waste oil and activated carbon powder. To make it possible.

The filter unit 30 is further filtered through a mixture of the waste oil and activated carbon powder introduced in the stirrer 10 and introduced.

As shown in FIG. 1, the filter unit 30 includes a primary filter unit 30a, a secondary filter unit 30b, a tertiary filter unit 30c, and a fourth filter unit 30d. These filter units 30a-30d are characterized in that they are sequentially positioned in multiple stages. The first to third filter units 30a to 30c include a bag filter (not shown) for sequentially removing impurities by size, and the fourth filter unit 30d finally removes impurities. It includes a membrane filter (not shown) that completely removes.

The primary filter unit 30a removes impurities having a capacity of 27.5 L and a diameter of about 10 μm or more. The secondary filter part 30b and the tertiary filter part 30c have a capacity of 25 L and remove impurities having a diameter of about 1 μm or more and less than 10 μm. The fourth-order filter part 30d, which is the filter part of the final stage, has a capacity of 20 L and completely removes impurities (an impurity having a diameter of approximately 0.6 mu m). The regenerated oil coarse up to the fourth filter unit 30d is sampled and shipped as a product.

As the bag filter of the primary filter unit 30a, the product name PE-10-P02S (standard 10μ × Φ180 × 810) manufactured by Inprus Tech Co., Ltd. is used, and the bag filter of the secondary filter unit 30b is manufactured. It uses the product name POXL-1-PO2E (standard 1μ × Φ180 × 810) of Rustech, and as the bag filter of the tertiary filter unit 30c, product name AGF-51-E02E (standard 1μ × Φ180 × 810) is used. In addition, the membrane filter of the 4th filter part 30d uses the product name CSP-7P1S-2A-0.6A (standard 0.6 micrometer x 20 micrometers x 3-stage filter) of CS Technophil Co., Ltd. For reference, the membrane filter is widely known as a reverse osmosis filter, and is generally used in water purifiers and also used for deionized water production used in semiconductor manufacturing processes.

However, the present invention is not limited thereto, and as the filter constituting the filter unit 30 of the regeneration device 100 of the vacuum pump oil of the present invention, various types of filters currently commercially available can be used. Those skilled in the art will readily understand.

Hereinafter, the regeneration method of the vacuum pump oil of the present invention will be described in detail with reference to FIGS. 1 and 2.

Vacuum pump oil regeneration method of the present invention can be largely divided into the step of removing the water and impurities of the waste oil in the stirrer 10, and the step of filtering and removing the impurities sequentially by size in the filter unit (30).

First, referring to FIG. 2, the waste oil used in the vacuum pump is recovered (S200), and the state of the waste oil is checked (S210). If the result of the check indicates that the waste oil may be directly put into the stirrer 10 (YES), the waste oil is put into the stirrer 10 (S230). After separating and removing the water and other oil layers (S220), the waste oil from which the water and other oil components are removed is introduced into the stirrer 10 (S230). At this time, before the waste oil is put into the stirrer 10, the actual weight of the waste oil is measured. Then, activated carbon is prepared and 0.5% by weight of activated carbon is added to the stirrer 10 based on the measured weight of the waste oil (S240). As a kind of activated carbon, powdered activated carbon (obtained from Cheil Carbon Industry) is used.

After the waste oil and activated carbon are put into the stirrer 10, the stirrer motor 12 of the stirrer 10 is turned ON to operate the stirrer motor 12 and the rotational speed of the rotating shaft of the stirrer (stirring speed) ) Is set at 600 to 700 rpm. In order to raise the internal temperature of the stirrer 10, the stirrer temperature switch (not shown) is turned ON to heat the inside of the stirrer, and the rising temperature is set to 80 ° C. At this time, the injected waste oil and activated carbon powder are mixed and stirred. When the temperature (stirring temperature) inside the stirrer 10 rises to 80 ° C., the stirring speed of the stirrer 10 is lowered to 400 rpm and the stirrer 10 is operated ( S250).

After the stirring speed of the mixture of the waste oil and the activated carbon powder is lowered to 400 rpm, the running time of the stirrer 10 is determined according to the weight of the waste oil injected into the stirrer 10. For example, if the weight of waste oil put into the stirrer 10 is 100kg, the stirrer 10 is operated for 4 hours, and if the weight of waste oil put into the stirrer 10 is 200kg, 300kg, 400kg, 500kg, 600kg, 700kg The running time of (10) is set to 8 hours, 12 hours, 16 hours, 20 hours, 24 hours and 28 hours, respectively.

When the operation of the stirrer 10 is completed, the internal temperature of the stirrer 10 is set to 40 ° C. to lower the temperature of the mixture of waste oil and activated carbon powder to 40 ° C. (S260). When the mixture of 40 ° C. or more is introduced into the filter part 30, the bag filter and the membrane filter constituting the filter part 30 are damaged and the impurity filtration function of the filter part 30 does not work. Care should be taken not to flow into (30).

When the internal temperature of the stirrer 10 is 40 ° C. or less, the on / off valve 24 provided in the flow line 20 is opened, and the supply pump 22 is operated to collect waste oil and activated carbon powder treated in the stirrer 10. The mixture is forced into the filter unit 30 (S270). In this case, before operation of the feed pump 22, the presence or absence of an abnormality in the pressure gauge of the first to fourth filter sections 30a-30d is checked.

On the other hand, in the present invention, by adding activated carbon to the stirrer 10 it is possible to maintain the viscosity and color required for the regeneration oil. That is, activated carbon has a strong adsorption force, so that foreign matter or residues mixed in the waste oil can be adsorbed, and discolored color of the waste oil can be removed. If the activated carbon is not used, even if the foreign matter mixed in the waste oil is filtered to some extent in the subsequent filter part 30, there is a limit that the foreign matter cannot be completely filtered in the filter part 30, in particular, the discolored chromaticity. It cannot be removed from the filter unit 30. Therefore, it is important to remove impurities of waste oil and remove chromaticity by using activated carbon primarily in the stirrer 10.

In addition, in the present invention, by raising the temperature inside the stirrer 10, the water and gas residues remaining in the waste oil can be effectively removed. That is, there is a possibility that residual oil, including gas, used in the semiconductor process may remain in the waste oil recovered by the vacuum pump. When the regeneration oil is used without removing the residual water and gas residues from the regeneration oil, the inside of the vacuum pump may be corroded. In the present invention, the temperature inside the stirrer 10 is raised and stirred for a long time to remove the water and gas residues. Done.

As a result, in the present invention, by using the activated carbon and stirring for a long time by raising the temperature inside the stirrer, it is possible to effectively remove impurities and moisture contained in the waste oil, while maintaining the viscosity and color required for the vacuum pump regeneration oil.

On the other hand, the waste oil which is first processed in the stirrer 10 and introduced into the filter unit 30 is sequentially filtered out of impurities in the filter unit 30 by size. That is, the primary filter part 30a removes impurities having a diameter of about 10 μm or more (S282), and the secondary filter part 30b removes impurities having a diameter of about 1 μm or more and less than 10 μm (S284), In the tertiary filter portion 30c, impurities having a diameter of about 1 µm or more and less than 10 µm are removed (S286). In the fourth filter part 30d, which is the filter part of the final step, impurities are completely removed (S288). The regenerated oil that passed through the fourth filter unit 30d is shipped as a final product after undergoing sample inspection (S290) (S292).

In the present invention, by removing the impurities of the waste oil by size sequentially using a multi-stage filter, it is possible to reliably remove the fine foreign matter that may remain in the regeneration oil. Thus, the regenerated oil product passing through the final membrane filter will have almost the same viscosity, color and physical properties as the new vacuum pump oil product.

The performance of the regenerated regenerated oil was tested according to the regeneration method of the vacuum pump oil of the present invention, and the analysis result was confirmed.

The performance test was carried out by the Korea Oil Quality Inspection Office. The test request vacuum pump regenerated oil recycled according to the method of the present invention was regenerated by a two-stage filter process (Example 1) and a four-stage filter process, which was a mixture of Pomplin waste oil and Klytox waste oil. (Example 2).

Performance analysis of the regenerated oil of Example 1 and Example 2 recycled according to the method of the present invention was carried out for a variety of analysis items, performance analysis for the new product vacuum pump oil, Pomblein vacuum pump oil and Klytox oil. Was carried out. As analysis items, kinematic viscosity, viscosity index, pour point, color, refractive index, copper plate corrosion, base oil, and FT-IR spectra were measured, and analysis conditions, analysis methods, and analysis results for each analysis item are shown in Table 1 below.

Table 1. Vacuum Pump Oil Analysis Data

As shown in Table 1, when looking at the viscosity index, color, and copper plate corrosion, which is the most important analysis item in the vacuum pump regeneration oil, the regeneration oil of Example 1 and Example 2 regenerated according to the method of the present invention is a new product vacuum It can be seen that it shows almost the same performance as the pump oil.

3 to 5 show FT-IR spectra of new vacuum pump oils, and FIGS. 6 and 7 show FT- of recycled oils of Example 1 and Example 2, respectively, recycled according to the method of the present invention. IR spectrum is shown. As can be seen from these figures, it can be seen that the regeneration oils of Examples 1 and 2 exhibited FT-IR spectra that are almost identical to or similar to new vacuum pump oils. It can be seen that the recycled oil has almost the same physical properties as the new vacuum pump oil.

Therefore, it was confirmed again that the vacuum pump oil regeneration method of the present invention is a method for inexpensively and efficiently regenerating the vacuum pump oil while maintaining the properties of the vacuum pump oil.

As mentioned above, although this invention was demonstrated to the said Example, this invention is not limited to this. Those skilled in the art can make modifications and changes without departing from the spirit and scope of the present invention, and it will be appreciated that such modifications and changes also belong to the present invention.

1 is a block diagram of a vacuum pump oil regeneration device 100 of an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a method of regenerating vacuum pump oil for each stage by using the vacuum pump oil regeneration apparatus 100 of FIG. 1.

3 is a graph of the FT-IR spectrum analysis of a new vacuum pump oil (fomblin oil 25/06).

4 is an FT-IR spectrum analysis graph of a new product vacuum pump oil (fomblin oil 16/06).

5 is a FT-IR spectrum analysis graph of a new product vacuum pump oil (Klytox oil 1525).

6 is a FT-IR spectrum analysis graph of the regeneration oil of Example 1 regenerated according to the method of the present invention.

7 is a FT-IR spectrum analysis graph of the regeneration oil of Example 2 recycled according to the method of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: regeneration device for vacuum pump oil

10: stirrer 12: stirrer motor

14: exhaust pipe 16: exhaust fan

20: flow passage 22: feed pump

24, 28: on-off valve 26: bypass pipe

30: filter part

30a: primary filter unit 30b: secondary filter unit

30c: 3rd order filter part 30d: 4th order filter part

Claims (10)

Recovering waste oil, Preparing an activated carbon powder, In order to maintain the required viscosity in the regeneration oil, to remove the discolored color of the waste oil and to remove the water, impurities and gas residues remaining in the waste oil, the recovered waste oil and the activated carbon powder is mixed and the waste oil Raising the stirring temperature of the mixture of the activated carbon powder to a constant temperature, and reacting the mixture of the waste oil and the activated carbon powder with stirring for a predetermined time; Lowering the temperature of the mixture to a constant temperature; The method of regenerating a vacuum pump oil comprising the step of filtering the mixture is lowered temperature through a filter. The method of claim 1, The activated carbon powder is mixed with the waste oil in a proportion of 0.5% by weight of the vacuum pump oil, characterized in that the mixing. The method according to claim 1 or 2, When the stirring temperature of the mixture of the waste oil and the activated carbon powder is raised to a constant temperature, the rising temperature is 80 ℃, and in the step of lowering the temperature of the mixture to a constant temperature, the falling temperature is characterized in that 40 ℃ Regeneration method of vacuum pump oil. The method according to claim 1 or 2, The initial stirring speed of the mixture of the waste oil and the activated carbon powder is 600 to 700 rpm, and when the stirring temperature is increased to 80 ℃, the vacuum pump, characterized in that to lower the stirring speed of the mixture of the waste oil and activated carbon powder to 400 rpm How to regenerate oil. The method of claim 4, wherein Reducing the stirring speed of the mixture of the waste oil and the activated carbon powder to 400 rpm, the method of regenerating the vacuum pump oil, characterized in that for stirring for 4 hours the mixture based on the weight of the waste oil 100kg. The method according to claim 1 or 2, The plurality of filters are provided in a plurality of stages, and the filter of the last stage is a membrane filter regeneration method, characterized in that the membrane filter. Waste oil and activated carbon powder are added and mixed, the stirring temperature of the mixture of waste oil and activated carbon powder is raised to a constant temperature, and the mixture of waste oil and activated carbon powder is reacted with stirring for a predetermined time, A stirrer that maintains the viscosity, removes the discolored color of the waste oil, removes residual water, impurities and gas residues in the waste oil, and lowers the temperature of the mixture to a constant temperature after the reaction is completed; Recycling apparatus of the vacuum pump oil including a plurality of filters in which the mixture of the waste oil and the activated carbon powder inlet is filtered by the completion of the reaction in the stirrer and discharged through the flow passage. The method of claim 7, wherein And a pump provided to the flow passage and pumping the mixture from the stirrer to the filters. The method according to claim 7 or 8, The filter is a regeneration device of a vacuum pump oil, characterized in that the primary filter, the secondary filter, the tertiary filter and the fourth filter are sequentially positioned in multiple stages. The method of claim 9, The first to third filters are bag filters for sequentially removing impurities by size, and the fourth filter is a membrane filter for finally removing impurities completely.

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