JP2008157077A - Compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compressor preventing leakage (inflow) of fluid having the same component as the compressed fluid into a bearing part, and suppressing increase in manufacturing cost while implementing shaft-seal of compressed fluid (product gas). <P>SOLUTION: The compressor comprises: a casing 11; a shaft body 14 rotatably supported in the casing 11 through bearing parts 12, 13; an impeller attached to the shaft body 14 and rotated to compress the compressed fluid G; shaft seal parts 17, 18 each of which is fixed in the casing 11 and is projected toward a shaft body 14 side, and to which the fluid (first fluid) 16 having the same component as the compressed fluid is supplied to shaft-seal the compressed fluid G; a second supply passage 20 supplying inert gas 19 into the casing 11; pumps 22, 23 connected to the casing 11 to discharge the inert gas in the casing 11. Therefore, flowing of the first fluid 16 into the bearing parts 12, 13 is prevented. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a compressor, and more particularly to a compressor suitable for use in a process for compressing butadiene gas in a process for producing butadiene rubber.

  The product manufacturing method may include a step of compressing a product gas as a raw material to a predetermined pressure by a compressor. In such a compressor, the product gas (to the bearing portion that rotatably supports the shaft body to which the impeller of the compressor is attached is conventionally used by using a method called oil seal or a method called buffer gas seal. The product gas is shaft-sealed while suppressing leakage of the fluid to be compressed (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 10-148198

  However, if the above-described method called oil seal is used, the compressed fluid can be sealed, but this method requires a mechanism such as a lubricating oil, a pump, and a control valve, and the mechanism itself is complicated. Since the maintenance is complicated, the manufacturing cost is increased.

  In the above-described technique called buffer gas seal, a clean gas having the same composition as the product gas is supplied to a shaft seal portion fixed in a casing (compressor main body) and having a protruding shape on the shaft body side. Although the shaft seal can be performed more easily than the method using an oil seal, the product gas is a polymer raw material gas that is polymerized under a predetermined environmental condition such as butadiene gas. In some cases, if this gas flows into the bearing portion and becomes a polymer at this location, the performance of the bearing portion may be degraded. Moreover, although the performance deterioration of the bearing part mentioned above can be suppressed by stopping the compressor (stopping the operation) and carrying out regular maintenance, this increases the manufacturing cost due to the increase in maintenance cost and the reduction in manufacturing efficiency. .

  Therefore, the present invention has been proposed in view of the above circumstances, and prevents leakage (inflow) of a fluid having the same component as the fluid to be compressed into the bearing portion while sealing the fluid to be compressed (product gas). An object of the present invention is to provide a compressor that can suppress an increase in manufacturing cost.

  A compressor according to a first aspect of the present invention that solves the above-described problem includes a casing, a shaft body that is rotatably supported by the casing via a bearing portion, and is attached to the shaft body and rotates to be compressed fluid. An impeller that compresses the compressed fluid, and a shaft sealing portion that is fixed in the casing, has a protruding shape toward the shaft body side, and is supplied with a fluid having the same component as the fluid to be compressed, and shaft seals the fluid to be compressed And a supply means connected to the casing for supplying an inert gas into the casing, and an exhaust means connected to the casing for exhausting the inert gas in the casing.

  A compressor according to a second invention for solving the above-described problem is the compressor described in the first invention, wherein the supply means is disposed in the vicinity of the bearing portion, and the exhaust means is the cover. It is arranged between the supply position of the fluid having the same component as the compressed fluid and the supply means.

  A compressor according to a third invention that solves the above-described problem is the compressor described in the first or second invention, wherein the exhaust means is a diaphragm type (exhaust device having no sliding portion). It is characterized by that.

  The compressor which concerns on 4th invention which solves the subject mentioned above is a compressor described in 3rd invention, Comprising: It further comprises the tank arrange | positioned between the said exhaust means and the said casing. Features.

  A compressor according to a fifth invention that solves the above-described problem is the compressor described in any one of the first to fourth inventions, wherein there are two exhaust means, and these are arranged in parallel. It is characterized by that.

  A compressor according to a sixth invention for solving the above-described problem is the compressor described in any one of the first to fifth inventions, wherein the fluid to be compressed is butadiene gas. .

  According to the compressor according to the first aspect of the invention, the fluid to be compressed is shaft-sealed by the fluid having the same component as the fluid to be compressed. In addition, since the inert gas is supplied into the casing by the supply means, and the inert gas is exhausted from the casing by the exhaust means, it is possible to prevent the fluid having the same component as the fluid to be compressed from flowing into the bearing portion. it can. Furthermore, since the fluid having the same component as the fluid to be compressed is exhausted from the casing by the exhaust means, it is possible to prevent the fluid from flowing into the bearing portion. Further, the structure is simple, and an increase in manufacturing cost can be suppressed.

  According to the compressor according to the second invention, the same effect as the compressor according to the first invention can be obtained, and the position between the supply position of the fluid having the same component as the fluid to be compressed to the casing and the bearing portion can be obtained. In this case, the exhaust means is disposed, and the fluid is surely exhausted by the exhaust means before flowing out to the bearing portion side. Further, an inert gas is supplied in the vicinity of the bearing portion by the supply means, and this gas can prevent the fluid having the same component as the fluid to be compressed from flowing into the bearing portion. Therefore, it is possible to more reliably prevent the fluid having the same component as the fluid to be compressed from flowing into the bearing portion.

  According to the compressor according to the third invention, in addition to the same effects as the compressor described in the first or second invention, even if a fluid having the same component as the fluid to be compressed flows into the exhaust means. Since there is no need to provide a special mechanism for sealing the fluid and the outside of the exhaust means, an increase in manufacturing cost due to the provision of such a special mechanism can be suppressed.

  According to the compressor of the fourth invention, in addition to the same effects as the compressor described in the third invention, by providing a tank, pressure fluctuation due to the operation of the exhaust means can be suppressed, It is possible to suppress and prevent mixing of the bearing portion into the lubricating oil and mixing of the fluid to be compressed into the exhaust means due to the pressure fluctuation. This can prevent the quality (component) of the compressible fluid from deteriorating.

  According to the compressor according to the fifth aspect of the present invention, the same effect as the compressor according to any one of the first to fourth aspects of the present invention can be achieved. By using the other as a spare machine, the compressor can be operated continuously.

  According to the compressor of the sixth invention, the same effect as the compressor according to any one of the first to fifth inventions is exhibited, and also under the environment of the polymerization reaction of butadiene gas (at about 90 ° C. or higher). Even if the temperature reaches a concentration of about 90% or more, the fluid to be compressed is sealed with a fluid having the same component as the fluid to be compressed. Furthermore, it can be mixed with an inert gas and prevented from flowing into the bearing portion. Therefore, there is no possibility that the performance of the bearing portion deteriorates due to the generation of a polymer due to the polymerization reaction of the fluid having the same component as the fluid to be compressed.

The best mode for carrying out the compressor according to the present invention will be described below.
FIG. 1 is a schematic view of a compressor according to an embodiment of the present invention.

  As shown in FIG. 1, a compressor 30 according to an embodiment of the present invention includes a casing 11, a shaft body 14 that is rotatably supported in the casing 11 via bearing portions 12 and 13, and the shaft body 14. And an impeller (not shown) that rotates and compresses the fluid G to be compressed, is fixed in the casing 11, has a protruding shape toward the shaft body 14, and has the same component as the fluid G to be compressed (First fluid) 16 is supplied through the first supply passage 15, and is connected to shaft sealing portions 17 and 18 that seal the fluid G to be compressed and the casing 11, and an inert gas 19 is provided in the casing 11. A second supply passage (supply means) 20 for supplying the exhaust gas, and two pumps (exhaust means) 22 and 23 that are connected to the casing 11 and exhaust the inert gas in the casing 11 through the exhaust passage 21. It has. These pumps 22 and 23 are arranged in parallel.

  However, a plurality of shaft sealing portions 17 and 18 are arranged across the same direction as the axial direction of the shaft body 14 between the bearing portions 12 and 13 in the casing 11 and the impeller. Specifically, the first shaft seal portions 17a and 18a, the second shaft seal portions 17b and 18b, and the third shaft seal portion 17c are directed from the bearing portions 12 and 13 toward the impeller side. , 18c, and fourth shaft seal portions 17d, 18d are respectively disposed. The impeller is disposed at a large diameter portion of the casing 11. In the vicinity of the impeller in the shaft body 14, a pedestal 24 that protrudes outward is provided. Also at this location, a shaft sealing portion 17e that has a protruding shape toward the base 24 is provided. Thereby, the inflow to the bearing parts 12 and 13 side of the fluid G to be compressed is suppressed.

  The first supply passage 15 is connected to the vicinity of the impeller in the casing 11, specifically, between the third shaft seal portions 17 c and 18 c and the fourth shaft seal portions 17 d and 18 d, A fluid 16 having the same component as the fluid to be compressed G is supplied in the vicinity of the impeller. The second supply passage 20 is connected to the vicinity of the bearing portions 12 and 13 in the casing 11, more specifically, to the bearing portions 12 and 13 side than the first shaft seal portions 17 a and 18 a, and the bearing portions 12 and 13 are connected. An inert gas 19 is supplied in the vicinity. The exhaust passage 21 is located between the supply position of the first fluid 16 from the first supply passage 15 in the casing 11 and the second supply passage 20, specifically, the second shaft sealing portions 17 b and 18 b and the second supply passage 20. It is connected between the third shaft seal portions 17c and 18c.

  By connecting the passages 20 and 21 to the casing 11 at such positions, the exhaust passage 21 is disposed between the supply position of the first fluid 16 to the casing 11 and the bearing portions 12 and 13. Thus, before the first fluid 16 flows out to the bearings 12 and 13 side, the pumps 22 and 23 are more reliably exhausted from the casing 11 through the exhaust passage 21. Further, an inert gas 19 is supplied in the vicinity of the bearing portions 12 and 13, and the gas 19 can prevent the first fluid 16 from flowing into the bearing portions 12 and 13. Therefore, inflow of the first fluid 16 into the bearing portions 12 and 13 can be prevented more reliably. The size of the gap between the shaft seals 17 and 18 and the shaft body 14 and the size of the exhaust force of the pumps 22 and 23 are adjusted as appropriate, and the inflow of the fluid G to be compressed into the exhaust passage 21. Is suppressed.

  Since the pumps 22 and 23 described above are arranged in parallel, the compressor 30 can be operated continuously by individually controlling them and using one as an operating machine and the other as a spare machine.

  Examples of the pumps 22 and 23 described above include diaphragm type pumps (exhaust devices having no sliding parts). With such a pump, even if the first fluid 16 flows into the pumps 22 and 23 through the exhaust passage 21, the fluid 16 and the outside of the pumps 22 and 23 are sealed. Since there is no need to provide a special mechanism, an increase in manufacturing cost due to the provision of such a special mechanism can be suppressed.

  The compressor 30 described above includes a tank (storage device) 25 that stores gas flowing through the passage 21 between the pumps 22 and 23 and the casing 11, that is, in the middle of the exhaust passage 21. Thereby, the pressure fluctuation in the casing 11 due to the operation of the pumps 22 and 23 can be suppressed, and the mixing of the bearing portions 12 and 13 into the lubricating oil and the exhaust passage 21 of the compressed fluid G due to the pressure fluctuation. It is possible to suppress / prevent contamination. This can prevent the quality (component) of the compressible fluid G from deteriorating.

  Examples of the compressed fluid G described above include butadiene gas. Even if the fluid to be compressed G is butadiene gas and the environment of the polymerization reaction of the gas (temperature of about 90 ° C. or higher, concentration of about 90% or higher) is reached, the fluid G to be compressed is the first fluid 16. The shaft is sealed by. Furthermore, it can be mixed with the inert gas 19 and prevented from flowing into the bearing portions 12 and 13. Therefore, there is no possibility that the performance of the bearing portions 12 and 13 deteriorates due to the generation of a polymer due to the polymerization reaction of the first fluid 16.

  Further, a third supply passage 27 for supplying a separation gas (third fluid) 26 such as nitrogen which is an inert gas to the vicinity of the bearing portions 12 and 13 rather than the second supply passage 20 in the casing 11. Are concatenated. Thereby, inflow to the exhaust passage 19 of the lubricating oil which lubricates the bearing parts 12 and 13 is suppressed.

  That is, in the compressor 30 described above, the third supply passage 27, the second supply passage 20, the exhaust passage 21, and the first supply passage 15 are arranged in this order from the bearing portions 12 and 13 side to the impeller side. And connected to the casing 11. A check valve 28 is provided between the passages 15, 20, 21, 27 and the casing 11.

  Therefore, according to the compressor 30 described above, the compressed fluid G is shaft-sealed by the first fluid 16. In addition, since the inert gas 19 is supplied into the casing 11 and the gas 19 is exhausted from the casing 11 through the exhaust passage 21 by the pumps 22 and 23, the first fluid 16 flows into the bearing portions 12 and 13. Can be prevented. Furthermore, since the first fluid 16 is also exhausted from the casing 11 by the pumps 22 and 23, the fluid 16 can be prevented from flowing into the bearing portions 12 and 13. Further, the structure is simple, and an increase in manufacturing cost can be suppressed.

  In addition, although demonstrated using the compressor 30 provided with the two pumps 22 and 23 above, it is good also as a compressor provided with one pump, Even if it is such a compressor, the said compressor The same effect as 30 is produced.

  In the above description, the compressor 30 including the tank 25 has been described. However, a compressor that does not include the tank may be used, and even such a compressor has the same operational effects as the compressor 30.

  INDUSTRIAL APPLICABILITY The present invention can be used for a compressor that seals a fluid to be compressed and suppresses the flow of the fluid into a bearing portion, and particularly compresses butadiene gas or the like that generates a polymer by a polymerization reaction in a predetermined environment. It can be used for compressors.

It is a schematic diagram of a compressor concerning one embodiment of the present invention.

Explanation of symbols

11 Casing 12, 13 Bearing 14 Shaft 15 First supply passage 16 First fluid 17, 18 Shaft seal 19 Inert gas 20 Second supply passage 21 Exhaust passage 22, 23 Pump 24 Base 25 Tank 26 First Third fluid 27 Third supply passage 28 Check valve 30 Compressor G Fluid to be compressed

Claims (6)

A casing,
A shaft body rotatably supported by the casing via a bearing portion;
An impeller attached to the shaft and rotating to compress the fluid to be compressed;
A shaft sealing portion that is fixed in the casing, has a protruding shape toward the shaft body side, is supplied with a fluid having the same component as the fluid to be compressed, and shaft seals the fluid to be compressed;
A supply means connected to the casing for supplying an inert gas into the casing;
A compressor comprising exhaust means connected to the casing and exhausting inert gas in the casing. A compressor according to claim 1, wherein
The supply means is disposed in the vicinity of the bearing portion,
The compressor is characterized in that the exhaust means is disposed between a supply position of a fluid having the same component as the fluid to be compressed and the supply means. A compressor according to claim 1 or claim 2, wherein
The compressor characterized in that the exhaust means is a diaphragm type. A compressor according to claim 3, wherein
The compressor further comprising a tank disposed between the exhaust means and the casing. A compressor according to any one of claims 1 to 4,
A compressor characterized in that there are two exhaust means and these are arranged in parallel. A compressor according to any one of claims 1 to 5,
The compressor, wherein the fluid to be compressed is butadiene gas.

Images