JPH1190130A - Method for preventing oxidative deterioration of oil and oil filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the oxidative deterioration of oil such as lubricating oil as much as possible and to external the exchange cycle of the oil. SOLUTION: A mixture consisting essentially of TiO2 powder and SiO2 powder and further contg. a metal of the platinum group is oxidation-fired and further reduction-fired, and oil such as lubricating oil is brought into contact with the resultant fired product so as to prevent the oxidation deterioration of the oil. The ratio between the TiO2 powder and SiO2 powder is preferably 1:0.5 to 1:1.3. Platinum or palladium is suitable for use as the metal of the platinum group and the metal is preferably contained by 0.3-2 wt.% of the total amt. of the TiO2 powder and SiO2 powder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for preventing oxidation and deterioration of oil and an oil filter.

[0002]

2. Description of the Related Art At present, oil (lubricating oil) is used in various industrial machines. For example, in the screw-type air compressor 10 shown in FIG. 2, lubricating oil is circulated and used in order to improve the lubricity of the bearings 12, 12 and the sealing of the screw 14. That is, the lubricating oil stored in the bottom of the oil tank 16 is cooled by the oil cooler 18 by a differential pressure or an oil pump, and then the foreign matter such as solids mixed through the line filter 20 is filtered. To the bearings 12, 12 and the screw 14. The lubricating oil supplied to the bearings 12 and 12 returns to the oil tank 16 by an oil pipe (not shown), but the lubricating oil supplied to the screw 14 is supplied from the suction filter 22 and compressed by the screw 14. The mist is supplied to the upper part of the oil tank 16 in the air. The mist-like lubricating oil is separated from the compressed air by the mist separator 24 and
6 is collected at the bottom and used for circulation. On the other hand, the compressed air from which the lubricating oil has been separated by the mist separator 24 passes through an after-cooler 26 and a mist filter 28 and is supplied to the user. The amount of lubricating oil stored at the bottom of the oil tank 16 is managed by the level gauge 30. When the amount of lubricating oil at the bottom of the oil tank 16 becomes less than a certain amount, the lubricating oil is added and Keep the volume constant.

[0003]

In the air compressor shown in FIG. 2, the lubricating oil supplied to the screw 14 is in the form of a mist and the contact area with the air is increased.
Since it is exposed to a high temperature due to compression heat, it is easily oxidized and deteriorated. If the oxidation and deterioration of the lubricating oil progresses, sludge or the like is generated, and the sealing performance of the screw 14 is reduced, and there is a possibility that compressed air at a predetermined pressure cannot be obtained or the screw 14 or the like may be damaged. For this reason, in the screw type air compressor 10, when the operation time reaches a predetermined time, the operation is stopped and the lubricating oil is changed. As described above, when replacing the lubricating oil, the screw air compressor 10 must be stopped, and since there is a problem in processing the replaced lubricating oil, it is expected that the lubricating oil replacement cycle can be extended as much as possible. It is rare. In the food industry,
If oxidation and deterioration of food oils such as tempura oil can be prevented as much as possible and the replacement cycle can be extended, the frying amount can be increased and the waste oil processing amount can be reduced. Therefore, an object of the present invention is to provide an oil oxidation / deterioration prevention method and an oil filter which can prevent oxidation / deterioration of oil such as lubricating oil as much as possible and can prolong the oil exchange cycle than before. .

[0004]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have first prepared a mixture mainly composed of titanium dioxide powder and silicon dioxide powder and mixed with platinum,
It was bonded to the surface of the alumina spherical body with an adhesive, fired by oxidation, and fired by hydrogen reduction to obtain a fired product. Next, in the lubricating oil circulation line of the screw air compressor 10 shown in FIG. 2, by circulating and using the lubricating oil while being in contact with the obtained fired product, it is possible to extend the lubricating oil exchange cycle as compared with the related art. Know and arrived at the present invention. That is, the present invention provides an oil characterized in that an oil such as a lubricating oil is brought into contact with a calcined product obtained by calcining a mixture mainly composed of a titanium dioxide powder and a silicon dioxide powder and containing a platinum group metal. Method for preventing oxidation and deterioration of Also,
The present invention is an oil filter that filters foreign substances such as solids mixed in oil such as lubricating oil, in a material forming a filter material that comes into contact with the oil, mainly titanium dioxide powder and silicon dioxide powder. And a fired fine powder obtained by firing a mixture of a platinum group metal and a mixture thereof.

In the present invention, it is possible to use a baked product obtained by molding the mixture into a predetermined shape or bonding the mixture to the surface of a solid body having a predetermined shape which is durable with respect to the firing conditions. The fired product can be easily handled. Furthermore, by firing the mixture in an oxidizing atmosphere and then firing in a reducing atmosphere, the fired product obtained can be sufficiently provided with an oil oxidation / deterioration prevention function. Further, as a material for forming the filter material, a chemical fiber mixed with fired fine powder can be used. For example, a nonwoven fabric obtained using chemical fiber mixed with fired fine powder can be used. Alternatively, the fiber to which the fired fine powder is adhered can be used as a paper filter by mixing the fired fine powder with a material for forming a filter material, for example, a binder for joining the contacts of the fibers. Platinum or palladium is preferable as the platinum group metal.

According to the present invention, a baked product mainly composed of a titanium dioxide powder and a silicon dioxide powder and obtained by calcining a mixture containing a platinum group metal is brought into contact with an oil, thereby heating the mixture in a heating and oxidizing atmosphere. Even if oil is used, an increase in the acid value of the oil and an increase in the pentane-insoluble content can be suppressed. As a result, it is possible to extend the oil exchange cycle as compared with the related art. In addition, an oil filter using a filter material made of a material in which fired fine powder obtained by crushing the fired product or the like can be installed without providing a special device in an oil circulation path or the like. And the fired fine powder can be easily contacted.

[0007]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, it is important that a mixture mainly composed of titanium dioxide powder and silicon dioxide and mixed with a platinum group metal is fired to obtain a fired product. Here, the ratio between the titanium dioxide powder and the silicon dioxide is preferably 1: 0.5 to 1: 1.3. Further, as the platinum group metal, platinum or palladium can be suitably used, and the mixing amount of the platinum group metal is 0.3 to 2 with respect to the total amount of the titanium dioxide powder and the silicon dioxide.
It is preferably set to wt%. When firing such a mixture, a molded article obtained by molding the mixture into a predetermined shape may be fired, or the mixture may be adhered to the surface of a solid body made of alumina ceramic or the like having durability against firing conditions. It may be bonded and fired. Further, the firing conditions of the mixture are as follows: the mixture is heated in an oxidizing atmosphere (for example, in air).
After baking at a temperature of 00 to 1270 ° C., it is preferable to bake at 200 to 500 ° C. in a reducing atmosphere (for example, in a hydrogen atmosphere). By such calcination, a function of preventing oil oxidation / deterioration can be sufficiently imparted to the obtained calcined product. In this calcined product, TiO ₂ undergoes partial reduction during the reduction calcining and changes to Ti ₄ O ₇ , adsorbing CO and H ₂ in oil, suppressing the formation of pentane-insoluble components, and titania and platinum It is presumed that oxides present in the oil can be reduced by the group metal.

[0008] Since the obtained fired product has a predetermined shape such as a ball shape, it can be used by filling it in a column or the like. An example is shown in FIG. FIG. 1 is a diagram in which a column filled with the obtained fired product is installed in a lubricating oil circulation line of the screw air compressor 10 shown in FIG. 2 so as to contact the fired product with the lubricating oil. 1, the same members as those in FIG. 2 are denoted by the same reference numerals, and detailed description will be omitted. In FIG.
The column 32 was provided between the screw air compressor 10 and the line filter 20. The column 32 is filled with a ball-shaped fired product mainly made of titanium dioxide powder and silicon dioxide and obtained by firing a mixture of a platinum group metal, and lubricating oil which has come into contact with the fired product is filled. It is supplied to the bearings 12, 12 and the screw 14 of the screw type air compressor 10. In this way, by circulating and using the lubricating oil while contacting it with the fired product,
Deterioration is prevented, and the lubricating oil replacement cycle can be extended as compared with the case where the column 32 is not installed (FIG. 2). this is,
Since the CO or H ₂ of lubrication oxides is reduced and the lubricating oil in the oil is adsorbed by the baked product, the lubricating oil is presumed to become difficult to be oxidized and deteriorated.

In FIG. 1, even if the column 32 is not installed, the filter as a filter material forming the line filter 20 provided in the lubricating oil circulation line of the screw type air compressor 10 is mainly made of carbon dioxide. A filter composed of titanium powder and silicon dioxide powder and blended with a fired fine powder obtained by firing a mixture in which a platinum group metal is mixed may be used. Even in this case, when the lubricating oil passes through the filter of the line filter 20 and passes through foreign matters such as solids mixed therein, the lubricating oil and the fired fine powder can come into contact with each other. Such a calcined fine powder may be a mixture of titanium dioxide powder and silicon dioxide powder, and a mixture obtained by mixing platinum group metals may be calcined without molding into a predetermined shape, or may be molded into a predetermined shape and calcined. The fired product may be pulverized into fine powder. The fired fine powder obtained in this way is a chemical fiber forming a filter,
It can be used by being compounded in paper or nonwoven fabric. Here, as the chemical fiber, a synthetic fiber such as a nylon fiber or a polyester fiber made of a synthetic polymer, a rayon or the like obtained by melting, spinning and re-coagulating natural fiber can be used as a chemical fiber that can be used for a filter. Semi-synthetic fibers such as acetate spun as a derivative by subjecting a polymer of regenerated fibers or natural fibers to a chemical reaction can be used.

In order to mix the baked fine powder into the chemical fiber, a predetermined amount of the baked fine powder is added, and a uniformly dispersed molten or solution raw material is discharged from a spinneret or the like to form a fibrous form. Thereby, a chemical fiber in which the fired fine powder is blended can be obtained. The obtained chemical fiber may be woven and knitted to form a filter, or a non-woven fabric obtained by joining the contacts of fibers together with a binder or interlacing fibers with each other by a needle punch may be used as a filter. Such non-woven fabric may be paper-like or felt-like, but paper-like non-woven fabric,
It is preferable because it has higher strength than a felt-like nonwoven fabric and has durability against lubricating oil passing therethrough. Further, according to the wet method of manufacturing a nonwoven fabric by dispersing fibers in a solution in which a binder containing calcined fine powder is dissolved, the contacts of the fibers are joined by the binder, and the binder is attached to the outer peripheral surface of the fibers. Thus, a nonwoven fabric to which the fired fine powder is attached can be obtained. According to such a nonwoven fabric,
Since the calcined fine powder is attached to the outer peripheral surface of the fiber, the contact area of the calcined fine powder that can come into contact with the lubricating oil can be made wider than when the calcined fine powder is blended into the fiber.

The above description is based on the premise that the column 32 is filled with a baked product of a predetermined shape in the lubricating oil circulation line of the screw type air compressor 10 shown in FIG. This is an example in which the compound is used in the chemical fiber to be formed or attached to the surface of the chemical fiber. Even if a fired product molded into a predetermined shape is directly added to the lubricating oil, the oxidation and deterioration of the lubricating oil are prevented. be able to. Also, in place of lubricating oil, for edible oil such as tempura oil, similarly to lubricating oil, a mixture mainly composed of titanium dioxide powder and silicon dioxide and mixed with a platinum group metal is calcined to contact the calcined product. By doing so, oxidation and deterioration of the edible oil can be prevented as much as possible.

[0012]

The present invention will be described in more detail by way of examples. Example 1 (1) Production of calcined product 130 g of titanium dioxide powder, 170 of silicon dioxide powder
g, 0.9 g of platinum and 100 ml of ethanol were uniformly mixed in a mortar, and the powdery mixture obtained by evaporating the ethanol was adhered to the entire circumference of a 15 mm-diameter spherical alumina body with an adhesive. Next, the alumina spherical body to which the powdery mixture was attached was put into an electric furnace, and first, 1270
After oxidizing and firing at a temperature of 200 ° C., hydrogen reduction firing was further performed at a temperature of 200 ° C. After the firing was completed, the product was naturally cooled and cooled to room temperature, and then a spherical fired product was taken out of the electric furnace.
The obtained spherical fired product exhibited an electric resistance value of about 20 kΩ at room temperature, but exhibited semiconductor characteristics such that it decreased to an electric resistance value of about 10 kΩ by heating. (2) Prevention of oxidation and deterioration of lubricating oil The spherical fired product obtained in (1) is put into the lubricating oil circulation line of the screw type air compressor 10 (7.5 KW, lubricating oil amount 40 liters) shown in FIG. The column 32 packed with 200 pieces was installed, and the fired product was brought into contact with the lubricating oil. After running the screw-type air compressor 10 continuously for 3000 hours,
The lubricating oil stored at the bottom of the oil tank 16 was sampled and analyzed. The results of the analysis are shown in Table 1 below. Table 1
As is clear from FIG.
The lubricating oil that was operated continuously for 0 hours was almost the same as a new lubricating oil. Therefore, the screw type air compressor 10 is continuously operated for 300
After the continuous operation for 0 hours (total 6000 hours), the lubricating oil accumulated at the bottom of the oil tank 16 was sampled and analyzed. The analysis results are shown in Table 1 below.

[Table 1] As is clear from Table 1, the screw type air compressor 10 was
The lubricating oil that has been continuously operated for 000 hours is substantially the same as a new lubricating oil, and further continuous operation of the screw air compressor 10 is possible without replacing the lubricating oil.

COMPARATIVE EXAMPLE 1 Except that the column 32 used in Example 1 was not installed,
In the same manner as in the first embodiment, the screw type air compressor 10
After the continuous operation for 00 hours, the lubricating oil accumulated at the bottom of the oil tank 16 was sampled and analyzed.
The analysis results are shown in Table 2 below.

[Table 2] As shown in Table 2, the lubricating oil obtained by continuously operating the screw air compressor 10 for 3000 hours has an increased acid value and pentane-insoluble content, indicating that it has been oxidized and deteriorated. . For this reason, it is necessary to change the lubricating oil,
Subsequent experiments were stopped.

Example 2 and Comparative Example 2 (1) Example 2 Seven spherical baked products obtained in Example 1 were added to an electric fryer containing 1 liter of soybean oil as a tempura oil. The fried ingredients shown in Table 3 below were fried for 20 minutes.

[Table 3] After the frying was completed, the tempura oil was placed in a stainless steel bowl, allowed to cool for 30 minutes, and the supernatant was transferred to a container and cooled. When the acid value of the cooled tempura oil was investigated,
0.114 mgKOH / g. (2) Comparative Example 2 In Example 2, the fried materials in Table 3 were fried in the same manner as in Example 2 except that the seven spherical fired products obtained in Example 1 were not added. When the acid value was investigated, it was 0.1
It was 41 mgKOH / g. (3) Reference Example Soybean oil was put in an electric fryer, and only heating for about 20 minutes was performed without frying the frying material. At the time of this heating, the temperature of soybean oil was adjusted so as to be equal to the temperature at which the fried material was fried in Example 2 and Comparative Example 2. When the acid value of the soybean oil was examined after the heating was completed, it was found that the acid value was 0.
125 mg KOH / g. As is clear from the above-described Example 2, Comparative Example 2, and Reference Example, the frying material was fried while the spherical fired product obtained in Example 1 was present, thereby increasing the acid value of the tempura oil, that is, tempura. The progress of oxidation and deterioration of oil can be suppressed. For this reason, it is possible to fry a larger amount of frying material than in Comparative Example 2 without replacing the tempura oil.

[0015]

According to the present invention, since the progress of oxidation and deterioration of oil can be suppressed, the use time of the same oil can be extended as compared with the conventional oil. For this reason, loss due to oil change or operation stop of the device can be prevented as much as possible. Further, the processing of the replaced oil can be reduced, which is preferable in terms of resources and environmental protection.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a lubricating oil circulation line of a screw type air compressor to which an oil oxidation / deterioration prevention method according to the present invention is applied.

FIG. 2 is a schematic diagram illustrating a lubricating oil circulation line of a conventional screw type air compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Screw type air compressor 12 Bearing 14 Screw 16 Oil tank 18 Oil cooler 20 Line filter 22 Suction filter 24 Mist separator 26 Aftercooler 28 Mist filter 30 Gauge 32 Column

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // C10N 30:10 60:00 70:00

Claims (8)

[Claims] 1. Oxidation of oil characterized by bringing oil such as lubricating oil into contact with a calcined product obtained by calcining a mixture mainly composed of titanium dioxide powder and silicon dioxide and mixed with a platinum group metal. -How to prevent deterioration. 2. The oxidation of oil according to claim 1, wherein the mixture is formed into a predetermined shape, or a baked product obtained by bonding the mixture to the surface of a solid body having a predetermined shape having durability against calcination conditions and calcination. -How to prevent deterioration. 3. The method for preventing oxidation / deterioration of oil according to claim 1, wherein platinum or palladium is used as the platinum group metal. 4. After firing the mixture in an oxidizing atmosphere,
The method for preventing oxidation and deterioration of an oil according to any one of claims 1 to 3, wherein the firing is performed in a reducing atmosphere. 5. An oil filter for filtering foreign matter such as solid matter mixed in oil such as lubricating oil, wherein a material forming a filter material in contact with the oil mainly includes titanium dioxide powder and silicon dioxide powder. An oil filter characterized by using a fired fine powder which is obtained by firing a mixture of a platinum group metal and a mixture of platinum group metals. 6. The oil filter according to claim 5, wherein the material forming the filter material is a chemical fiber in which baked fine powder is blended. 7. The oil filter according to claim 5, wherein the material forming the filter material is a non-woven fabric obtained by using chemical fibers mixed with fired fine powder. 8. The oil filter according to claim 5, wherein a fiber to which a fired fine powder is attached is used as a material forming the filter material.