JP2019039471A - Shaft seal device - Google Patents

Abstract

To present an excellent mechanical seal function even in a case where a liquid in a sealed fluid region contains foreign substances such as solid particulates.SOLUTION: A shaft seal device M2 is configured to seal a sealed fluid region D that is a liquid region, with a mechanical seal 31 comprising a case-side seal ring 37 which is provided in a seal case 33, and a shaft-side seal ring 35 which is provided in a rotary shaft 34. In the shaft seal device, the mechanical seal 31 is configured into a non-contact mechanical seal in which both the seal rings are relatively rotated in a non-contact state. Heating means 42 which evaporates a liquid in the sealed fluid region D is provided in a sealed fluid end region D1 facing seal end faces 35a and 37a of both the seal rings 35 and 37 in the sealed fluid region D.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a shaft seal device used for rotating equipment such as a pump, a stirrer, a blower and a turbine for handling a liquid.

  As a conventional shaft seal device of this type, for example, as disclosed in Patent Document 1, two end-face contact type mechanical seals are arranged in tandem in the axial direction, and an in-machine region that is a liquid region and a device that is an air region. A tandem double seal (hereinafter referred to as “conventional shaft seal device”) configured to seal an outer region via an intermediate region formed between both mechanical seals is well known.

  In the conventional shaft seal device, each mechanical seal is held in a shaft-side sealing ring fixed to the rotating shaft and a seal case so as to be movable in the axial direction via an O-ring, and pressed to the shaft-side sealing ring. The case-side seal ring is configured to exert a sealing function by rotating relative to the case-side seal ring. By supplying the intermediate liquid to the intermediate region, the contact portion of both seal rings in each mechanical seal is liquid. And is designed to prevent liquid in the in-machine region from leaking from the in-machine region side mechanical seal to the atmosphere region.

Japanese Patent Application Laid-Open No. 08-082373

  However, in the conventional shaft seal device, if foreign matter such as solid particulates is mixed in the liquid in the in-machine region, in the in-machine mechanical seal, the contact part between both seal rings or the contact part between the case side seal ring and the O-ring There is a possibility that foreign matters such as solid fine particles may invade and the mechanical seal function may be deteriorated or lost.

  An object of the present invention is to provide a shaft seal device that can satisfactorily seal a liquid even when the liquid contains foreign matters such as solid fine particles without causing such problems.

  In order to achieve the above object, the present invention seals a sealed fluid region, which is a liquid region, with a mechanical seal including a case-side sealing ring provided on a seal case and a shaft-side sealing ring provided on a rotary shaft. A shaft seal device configured as described above, in which the liquid in the sealed fluid region is vaporized in the sealed fluid end region facing both sealed end surfaces that are opposite end surfaces of both sealed rings of the mechanical seal in the sealed fluid region The present invention proposes a shaft seal device provided with a heating means.

  In a preferred embodiment of such a shaft seal device, as the mechanical seal, a dynamic pressure generating groove is formed in one of both sealed end faces, and the both sealed end faces are generated by generating dynamic pressure therebetween. Use a non-contact type mechanical seal configured to hold the contact state, or form a static pressure generating groove on one of both sealed end surfaces as the mechanical seal, and generate the static pressure on both sealed end surfaces. A non-contact type mechanical seal configured to maintain a non-contact state is used by generating a static pressure between both sealed end surfaces by supplying a high-pressure seal gas from the sealed fluid region to the groove.

  Further, the shaft seal device of the present invention provides a second mechanical seal closer to the atmosphere region than the mechanical seal, and supplies a buffer gas to an intermediate region closed by the mechanical seal and the second mechanical seal. And it can comprise so that a to-be-sealed fluid area | region and an air | atmosphere area | region may be sealed via an intermediate area | region with the said both mechanical seals. In this case, the two mechanical seals each include a case-side sealing ring provided on the seal case and a shaft-side sealing ring provided on the rotating shaft, and are formed on one of the two sealing end faces that are opposite end faces of the two sealing rings. It is preferable that the non-contact type mechanical seal is configured to generate a dynamic pressure between the both sealed end surfaces by the generated dynamic pressure generating groove so as to keep the sealed end surfaces in a non-contact state.

  Further, in the shaft seal device of the present invention, the heating means is configured to provide a hollow heating jacket on the inner peripheral portion of the seal case and supply a heating fluid into the heating jacket. Is preferred. In addition, a cooling means for preventing the liquid in the sealed fluid area from being vaporized by the heating means is provided in the sealed fluid end area near the heating means and opposite to the mechanical seal across the heating means. It is preferable to keep it. In this case, it is preferable that the cooling means is configured to provide a cooling jacket adjacent to the heating jacket on the inner peripheral portion of the seal case and supply the cooling fluid into the cooling jacket. Furthermore, it is preferable to load a heat insulating material between the heating jacket and the cooling jacket.

  In the shaft seal device of the present invention, the liquid in the sealed fluid region is not in direct contact with the mechanical seal that seals the sealed fluid region, but the vaporized gas obtained by vaporizing the liquid by the heating means is in contact with the mechanical seal. Therefore, even when the liquid contains foreign matter such as solid fine particles, the foreign matter may enter between the structural members of the mechanical seal to deteriorate or lose the sealing function of the mechanical seal. And a good and stable mechanical seal function is exhibited. In addition, since a non-contact type mechanical seal that does not come into contact with the sealed end face can be used as a mechanical seal that seals gas such as vaporized gas or buffer gas of the liquid, a conventional shaft seal device that uses an end face contact type mechanical seal Compared to the above, the torque acting on the rotating shaft is small, and the power cost of the rotating shaft can be greatly reduced.

FIG. 1 is a cross-sectional view showing an example of a shaft seal device according to the present invention. FIG. 2 is a sectional view showing a modification of the shaft seal device according to the present invention. FIG. 3 is a cross-sectional view of a main part showing another modification of the shaft seal device according to the present invention.

  FIG. 1 is a sectional view showing an example of a shaft seal device according to the present invention. A shaft seal device (hereinafter referred to as a “first shaft seal device”) M1 shown in FIG. 1 is a low-boiling liquid (liquid ammonia, LPG, etc.). A mechanical seal (hereinafter referred to as “first mechanical seal”) 1 and a second gas seal (hereinafter referred to as “second mechanical seal”) that are arranged in the axial direction and are installed in a rotary device such as a pump that handles liquefied gas. 2), and an intermediate region C formed between the mechanical seals 1 and 2 is a sealed fluid region (in-machine region) A and an atmospheric region (external region) B, which are low-boiling liquid regions. It is sealed (isolated) via The sealed fluid region A is sealed by the first mechanical seal 1, and the intermediate region C is sealed by both mechanical seals 1 and 2.

  A first mechanical seal (primary seal) 1 on the low boiling point liquid region A side, as shown in FIG. 1, penetrates the seal case 4 concentrically with a cylindrical seal case 4 attached to the housing 3 of the rotating device. A shaft-side sealing ring 6 fixed to the rotating shaft 5 of the rotating device, a case-side sealing ring 7 held in the seal case 4 so as to be movable in the axial direction, and the case-side sealing ring 7 as the shaft-side sealing ring 6. It is a mechanical seal that includes a spring member 8 that is biased in the direction and that does not form a liquid lubricant film between the sealed end faces 6a and 7a, which are opposed end faces of the sealed rings 6 and 7. The second mechanical seal (secondary seal) 2 on the atmosphere region B side is movable in the axial direction with respect to the seal case 4, the shaft-side sealing ring 9 fixed to the rotating shaft 5, and the seal case 4. Both sealed end faces 9a, which are opposed end faces of the both seal rings 9, 10, comprising a case-side seal ring 10 held and a spring member 11 that urges the case-side seal ring 10 toward the shaft-side seal ring 9; 10a is a mechanical seal that does not form a liquid lubricating film between 10a.

  An intermediate region C closed by both mechanical seals 1 and 2 is a gas region to which a buffer gas G1 having a pressure higher than that of the sealed fluid region A and the atmospheric region B is supplied. As the buffer gas G1, a harmless gas, such as nitrogen gas, that is inert to the low-boiling liquid (liquefied ammonia, etc.) in the sealed fluid region A and that does not interfere with leakage to the atmosphere region B is used. Is done.

  The first shaft seal device M1 composed of both mechanical seals 1 and 2 has a double seal structure in which both case-side seal rings 7 and 10 are positioned on both axial sides of both shaft-side seal rings 6 and 9, Each of the mechanical seals 1 and 2 is configured as a dynamic pressure type non-contact type mechanical seal.

  That is, the shaft-side seal rings 6 and 9 are fixed to the fixed ring 12 attached to the rotary shaft 5 with the sealed end faces 6a and 9a facing in the opposite direction. On the sealing end faces 6a and 9a of the shaft-side sealing rings 6 and 9, dynamic pressure generating grooves 6b and 9b having a spiral shape or a helical shape that open to the intermediate region C are formed. Retaining rings 17, 18 are connected to the case-side sealing rings 7, 10 via O-rings 13, 14 and drive pins 15, 16. The holding rings 17, 18 are connected to the seal case 4 via O-rings 19, 20. And holding the spring members 8 and 11 between the seal case 4 and the holding rings 17 and 18 so that the case-side sealing rings 7 and 10 are respectively connected to the shaft side. The seal case 4 is held so as to be movable in the axial direction while being urged toward the seal rings 6 and 9. Therefore, according to the mechanical seals 1 and 2, the dynamic pressure generated by the buffer gas G1 in the intermediate region C is generated by the action of the dynamic pressure generating grooves 6b and 9b between the sealed end faces 6a and 7a or 9a and 10a, This dynamic pressure causes the sealed end faces 6a, 7a or 9a, 10a to rotate relative to each other in a non-contact state having a minute clearance, thereby sealing between the intermediate region C and the sealed fluid region A or the atmospheric region B ( Isolated).

  Thus, in the first shaft seal device M1, as shown in FIG. 1, the sealed fluid end region A1 facing the sealed end surfaces 6a and 7a of the first mechanical seal 1 in the sealed fluid region A is covered. Heating means 21 is provided for vaporizing the liquid (low-boiling liquid such as liquid ammonia) in the sealed fluid region A.

  In this example, the heating means 21 has a hollow heating jacket 22 attached to the inner peripheral portion of the seal case 4 and in the vicinity of the sealed end faces 6a and 7a of the first mechanical seal 1, as shown in FIG. A supply path 23 and a discharge path 24 communicating with the inside of the heating jacket 22 are formed in the case 4, and the heating fluid F <b> 1 is circulated and supplied into the heating jacket 21 through the supply path 23 and the discharge path 24.

  The heating jacket 22 is made of a metal having a hollow cylindrical shape surrounding the rotating shaft 5 in a concentric state adjacent to the rotating shaft 5, and the annular first and second side walls 22 a facing each other with an appropriate interval in the axial direction. , 22b and a cylindrical peripheral wall 22c that connects the inner peripheral ends of both side walls 22a, 22b, and the outer peripheral ends of both side walls 22a, 22b are attached to the inner peripheral portion of the seal case 4. The inner diameter of the peripheral wall 22c is set to be slightly larger than the outer diameter of the rotary shaft 5, and an annular gap 25 having a small radial dimension is formed between the opposed peripheral surfaces of the peripheral wall 22c and the rotary shaft 5. The sealed fluid end region A1 opposite to the first mechanical seal 1 (inside the machine) across the heating jacket 22 is attached to the inner periphery of the seal case 4 in the vicinity of the heating jacket 22. A labyrinth seal 26 is provided. The inner peripheral portion of the labyrinth seal 26 is close to the outer peripheral surface of the rotating shaft 5, and the sealed fluid region A on the inner side of the machine and the end of the sealed fluid on the outer side of the machine with the labyrinth seal 26 interposed therebetween. The flow of the low-boiling liquid is suppressed between the area A1 and the heat transfer is suppressed, and foreign matter such as solid fine particles contained in the low-boiling liquid is prevented from entering the heating area by the heating jacket 22 as much as possible. To do.

  Thus, according to the heating means 21 described above, both the side walls 22a and 22b and the peripheral wall 22c of the heating jacket 22 are heated by circulatingly supplying the heating fluid F1 into the heating jacket 22. Therefore, the low-boiling liquid in contact with the heating jacket 22 is vaporized, and the sealed fluid end region A1 between the sealed end surfaces 6a and 7a of the first mechanical seal 1 and the heating jacket 22 is low-boiling liquid. The vaporized gas region is filled with vaporized gas (for example, ammonia gas when the low-boiling liquid is liquid ammonia).

  The temperature of the heating fluid F1, the thickness and material of the side walls 22a and 22b and the peripheral wall 22c of the heating jacket 22, and the volume of the sealed fluid end region (vaporized gas region) A1 are determined by the low boiling point liquid in the sealed fluid region A. Depending on the properties (vaporization temperature and the like), the low-boiling liquid is appropriately selected and set on condition that the low-boiling liquid is surely vaporized and the sealed fluid end region A1 becomes a complete vaporized gas region.

  By the way, in a factory or facility where a rotating device using the first shaft seal device M1 is installed, generally, an appropriate high-temperature fluid (steam, hot water, waste heat gas, etc.) is used for cleaning, air conditioning, or the like. Since the supply equipment and the discharge equipment are equipped, it is preferable to use a high-temperature fluid such as steam used or discarded in the factory or facility as the heating fluid F1 supplied to the heating jacket 22.

  In the first shaft seal device M <b> 1 configured as described above, the low boiling point liquid is in contact with the heating jacket 22 in the sealed fluid end region A <b> 1 contacting the sealed end surfaces 6 a and 7 a of the first mechanical seal 1. Since the vaporized gas heated and vaporized by the contact is filled, the dynamic pressure type non-contact between the sealed fluid end region A1 which is the vaporized gas region and the intermediate region C which is the buffer gas region. It is sealed well by the first mechanical seal 1 which is a shape mechanical seal. Further, the intermediate region C that is a gas region and the atmospheric region B are also well sealed by the second mechanical seal 2 that is a dynamic pressure type non-contact mechanical seal. Therefore, although the sealed fluid region A is a liquid region (low boiling point liquid region), the sealed fluid region A and the atmospheric region B are separated by the dynamic pressure type non-contact type mechanical seals 1 and 2 that are gas seals. Is well sealed through the intermediate region C.

  Therefore, even when foreign matter such as solid fine particles is mixed in the low-boiling liquid in the sealed fluid region A, the low-boiling liquid does not come into contact with the sealed end surfaces 6a and 7a of the first mechanical seal 1. Since the vaporized gas which is vaporized by the heating means 21 and does not contain foreign matters such as solid fine particles comes into contact, the foreign matters such as solid fine particles contained in the low boiling point liquid are sealed between the sealed end faces 6a and 7a or between the holding ring 17 and the case side. A good and stable mechanical seal function is exhibited without intruding into the contact portion of the O-rings 13 and 19 loaded between the seal ring 7 and the seal case 4 to deteriorate or lose the mechanical seal function. The

  The two mechanical seals 1 and 2 are non-contact type mechanical units in which the sealing end surfaces 6a and 9a of the shaft-side sealing rings 6 and 9 and the sealing end surfaces 7a and 10a of the case-side sealing rings 7 and 10 are held in a non-contact state. Since it is a seal, the torque acting on the rotary shaft 5 is greatly reduced compared to a conventional shaft seal device using an end-face contact type mechanical seal in which both sealed end faces rotate in contact with each other. The running cost including is greatly reduced.

  Further, as described above, the heating fluid F1, which is a heating source for vaporizing the low boiling point liquid, is used as a high temperature fluid equipped in a factory or facility where the rotating device in which the first shaft seal device M1 is used is installed. When it can be procured using supply equipment or discharge equipment (such as steam or waste heat gas), the initial cost and running cost of the heating means 21 can be reduced by using the high-temperature fluid as the heating fluid F1. The installation cost and maintenance cost of the included first shaft seal device M1 can be greatly reduced.

  FIG. 2 is a sectional view showing a modification of the shaft seal device according to the present invention. The shaft seal device (hereinafter referred to as “second shaft seal device”) M2 shown in FIG. This is a single seal composed of one mechanical seal 31 and is a sealed fluid region (in-machine region) D that is a low-boiling point liquid region. And the atmospheric region (external region) E, which is a non-sealed fluid region, is shield-sealed.

  As shown in FIG. 2, the mechanical seal 31 includes a cylindrical seal case 33 attached to a housing 32 of the rotating device, and a shaft fixed to the rotating shaft 34 of the rotating device concentrically penetrating the seal case 33. A side seal ring 35, a case side seal ring 37 held in the seal case 33 via an O-ring 36 so as to be movable in the axial direction, and a spring member for biasing the case side seal ring 37 in the direction of the shaft side seal ring 35 38, a mechanical seal that does not form a liquid lubricating film between the sealed end faces 35a, 37a, which are the opposed end faces of the sealed rings 35, 37, and between the sealed gas passage 39 and the sealed end faces 35a, 37a. By supplying the sealing gas G2, the sealed end faces 35a, 37a rotate relative to each other in a non-contact state. It is a Karushiru "hereinafter).

  That is, as shown in FIG. 2, the seal gas passage 39 is formed between the static pressure generating groove 39 a formed in the sealed end surface 37 a of the case side sealing ring 37 and the opposed peripheral surface of the seal case 33 and the case side sealing ring 37. A communication space 39b, which is an annular space formed and sealed by O-rings 40a and 40b, a case-side passage 39c formed in the seal case 33 and communicating with the communication space 39b, and a case-side sealing ring 37. The seal ring side passage 39d communicates the communication space 39b and the static pressure generating groove 39a, and the seal gas G2 is supplied from the case side passage 39c to the static pressure generating groove 39a. The static pressure generating groove 39a is a shallow concave groove that is intermittently or continuously formed in a concentric ring shape with the sealing end surface 37a of the case side sealing ring 37, and an orifice 41 is disposed in the sealing ring side passage 39d. . The sealing gas G2 is a gas having a pressure higher than that of the sealed fluid region D and the atmospheric region E, and is harmless even if it flows into both the regions D and E and adversely affects the low boiling point liquid in the sealed fluid region D. Some inert (eg, nitrogen gas) is used.

  According to the static pressure type mechanical seal 31 configured as described above, a static pressure is generated between the sealed end faces 35a and 37a by the seal gas G2 supplied to the static pressure generating groove 39a, whereby the sealed end faces 35a, 37a is held in a non-contact state having a minute clearance and rotates relatively to seal (isolate) the two regions D and E.

  Thus, even in the second shaft seal device M2, as shown in FIG. 2, the sealed fluid end region facing the sealed end surfaces 35a and 37a in the sealed fluid region D is similar to the first shaft seal device M1. D1 is provided with a heating means 42 for vaporizing the low boiling point liquid (liquid ammonia or the like) in the sealed fluid region D.

  Since the heating means 42 has the same structure as the heating means 21 of the first shaft seal device M1, the components of the heating means 42 having the same configuration as the heating means 21 shown in FIG. In FIG. 2, the same reference numerals as those in FIG. In the second shaft seal device M2, a labyrinth seal similar to that of the first shaft seal device M1 is provided in the sealed fluid end region D1 on the opposite side (inside the machine) with the heating jacket 22 interposed therebetween. 26 is provided.

  Thus, in the second shaft sealing device M2 configured as described above, the low boiling point liquid in the sealed fluid region D comes into contact with the heating jacket 22 as in the first shaft sealing device M1. The sealed fluid end region D1 between the sealed end surfaces 35a and 37a and the heating jacket 22 is a vaporized gas region filled with the vaporized gas of the low boiling point liquid.

  Therefore, even in the second shaft seal device M2, the sealed fluid end region D1 and the atmospheric region E, which are vaporized gas regions, are well shielded and sealed by the static pressure mechanical seal 31, and the sealed fluid region D is low. Even when foreign substances such as solid fine particles are mixed in the boiling liquid, the foreign substances are loaded between the sealing end faces 35a and 37a or between the case-side sealing ring 37 and the sealing case 33, and the O-rings 36, 40a and 40b. The mechanical seal function is not deteriorated and lost due to intrusion into the contact portion, and a good and stable mechanical seal function is exhibited.

  Further, since the static pressure type mechanical seal 31 is a non-contact type mechanical seal in which both the sealing end faces 35a and 37a are rotated in a non-contact state, the static pressure type mechanical seal 31 is rotated as compared with a conventional shaft seal device using an end face contact type mechanical seal. The torque acting on the shaft 34 is greatly reduced, and the running cost including the power cost of the rotating shaft is greatly reduced. Further, the heating fluid F1 that is a heating source for vaporizing the low boiling point liquid is converted into a high-temperature fluid (steam or waste) that is installed in a factory or facility where the rotating device in which the second shaft seal device M2 is used is installed. In the case where it is possible to procure using a supply facility or a discharge facility of hot gas or the like, the second temperature including the initial cost and running cost of the heating means 42 can be obtained by using the high-temperature fluid as the heating fluid F1. The equipment cost and maintenance cost of the shaft seal device M2 can be greatly reduced.

  By the way, in the shaft seal devices M1 and M2, there is a concern that the vaporizing action by the heating means 21 and 42 extends to the labyrinth seal 26 side (inside the machine), thereby affecting the performance (pump performance and the like) of the rotating device. In this case, as shown in FIG. 3, a cooling means 43 is provided on the labyling seal 26 side with respect to the heating means 21 and 42, and the vaporizing action of the low boiling point heating means 21 and 42 is applied to the sealed fluid end region. It is preferable to prevent a large expansion from A1 and D1 to the sealed fluid areas A and D on the inside of the aircraft.

  The cooling means 43 includes heating means 21 and 42 in the sealed fluid end regions A1 and D1 opposite to the mechanical seals 1 and 31 (inside the machine) across the heating means 21 and 42 in the shaft seal devices M1 and M2. It is good to arrange in the vicinity. For example, as shown in FIG. 3, the cooling means 43 is disposed between the heating jacket 22 and the labyrinth seal 26, and a hollow cooling jacket 44 is attached to the inner peripheral portions of the seal cases 4, 33 and the seal case 4. 33, a supply passage 45 and a discharge passage 46 communicating with each other in the cooling jacket 44 are formed, and the cooling fluid F2 is circulated and supplied into the cooling jacket 44 through the supply passage 45 and the discharge passage 46.

  The cooling jacket 44 is made of a metal having the same shape as the heating jacket 22, and includes annular first and second side walls 44a and 44b opposed to each other at an appropriate interval in the axial direction, and both side walls 44a and 44b. It consists of a cylindrical peripheral wall 44 c that connects the inner peripheral ends and is close to the outer peripheral surface of the rotating shaft 5. Between the outer peripheral ends of the first side wall 44a on the heating jacket 22 side in the cooling jacket 44 and the second side wall 22b on the cooling jacket 44 side in the heating jacket 22, both side walls 22b and 44a are appropriately spaced in the axial direction. Are connected. The cooling jacket 44 is attached to the inner peripheral portion of the seal cases 4 and 33 integrally with the heating jacket 22.

  According to the cooling means 43 configured as described above, the cooling fluid F2 is circulated and supplied into the cooling jacket 44, whereby the side walls 44a, 44b and the peripheral wall 44c of the cooling jacket 44 are cooled and come into contact with the cooling jacket 44. The low boiling point liquid is not vaporized by the heating means 21, 42, and the vaporizing action of the low boiling point liquid by the heating means 21, 42 is from the sealed fluid end regions A1, D1 to the labyrinth seal 26 side (machine interior). It does not spread.

  Therefore, by providing the cooling means 43, there is a concern that the performance (pump performance, etc.) of the rotating device is affected by vaporizing the low boiling point liquid in the sealed fluid regions A and D by the heating means 21 and 42. This can be wiped off reliably. The temperature of the cooling fluid F2 and the material of the constituent walls 44a, 44b, 44c of the cooling jacket 44 are such that the heating means 21, 42 vaporizes the low boiling point liquid according to the properties of the low boiling point liquid in the sealed fluid region A. It is selected and set as appropriate on the condition that it can be surely prevented. Further, when a low-temperature fluid (cooling water, drainage, etc.) used or discarded at a factory or facility where the rotating device is installed can be used, it is preferable to use such a low-temperature fluid as the cooling fluid F2. .

  Incidentally, the cooling jacket 44 is preferably provided as close as possible to the heating jacket 22. However, if the jackets 22 and 44 are brought close to each other in this way, the heating action (vaporization) by the heating means 21 and 42 is achieved. Action) and the cooling action (vaporization prevention action) by the cooling means 43 interfere with each other, the vaporization action by the heating jacket 22 is inhibited by the cooling action by the cooling jacket 43, and the gas in the sealed fluid end regions A1, D1 There is a possibility that the conversion is not performed well. In such a case, as shown in FIG. 3, between the heating jacket 22 and the cooling jacket 44, that is, between the second side wall 22b of the heating jacket 22 and the first side wall 44a of the cooling jacket 44. It is preferable to fill with an appropriate heat insulating material 47. Of course, when there is no possibility that the heating action by the heating means 21, 42 is hindered by the cooling action by the cooling means 42, it is not always necessary to provide such a heat insulating material 47.

  The configuration of the present invention is not limited to the above-described embodiments, and can be appropriately improved and changed without departing from the basic principle of the present invention.

  For example, the first shaft seal device M1 includes the seal rings 6 and 7 of the first mechanical seal 1 and the seal rings 9 and 10 of the second mechanical seal 2 in the same manner as the shaft seal device disclosed in Patent Document 1. It is also possible to configure a tandem double seal having a tandem arrangement in which the axial positional relationships are the same. In this case, a dynamic pressure generating groove communicating with the sealed fluid end region (vaporized gas region) A1 is formed on one of the sealed end surfaces 6a and 7a of the first mechanical seal 1, and the sealed fluid region is formed in the intermediate region C. By supplying a buffer gas G1 having a pressure lower than that of A and a pressure higher than or equal to that of the atmosphere region B, the first mechanical seal 1 is sealed by the vaporized gas in the sealed fluid end region A1 with the sealed end surfaces 6, 7 A dynamic pressure type non-contact type mechanical seal in which dynamic pressure is generated therebetween and the sealed end faces 6a and 7a rotate relative to each other in a non-contact state is formed.

  Further, in the second shaft seal device M2 that is a single seal, a hydrodynamic non-contact type mechanical seal similar to the first mechanical seal 1 described above can be used instead of the static pressure type mechanical seal 31. .

  Further, depending on the sealing conditions such as the low speed of the rotating shaft, the mechanical seal constituting the shaft seal device of the present invention is an end face contact type mechanical seal that rotates relative to each other while the sealing end faces of both sealing rings are in contact with each other. As disclosed in Japanese Patent Application No. 2006-166630 or a general dry contact seal in which one or both of the seal rings are made of a material having excellent self-lubricating properties (such as carbon or polytetrafluoroethylene containing glass fiber). It is also possible to use a special dry contact seal with a diamond coating on the sealed end face.

  Moreover, the structure of the heating means 21 and 42 and the cooling means 43 is arbitrary, for example, the heating jacket 22 and the cooling jacket 44 can also be integrally formed in the seal cases 4 and 33, respectively. Further, the heating means 21 and 42 and the cooling means 43 can be configured to electrically heat and cool the jackets 22 and 44, rather than heating and cooling the jackets 22 and 44 with the fluids F1 and F2, respectively. However, as described above, when the jackets 22 and 44 are heated and cooled by the fluids F1 and F2, a high-temperature fluid or a low-temperature fluid that is used or discarded in a factory or facility where the shaft seal devices M1 and M2 are installed. Can be used as the heating fluid F1 and the cooling fluid F2, it is advantageous in terms of cost.

  As described above, the shaft seal device of the present invention is suitable in terms of operating cost when used in a rotating device that handles low-boiling liquids, but of course is limited to rotating devices that handle low-boiling liquids. Alternatively, it may be used in a rotating device that handles a liquid having a boiling point higher than that of water.

1 First mechanical seal (mechanical seal)
2 Second mechanical seal (second mechanical seal)
4 Seal Case 5 Rotating Shaft 6 Shaft Side Seal Ring 7 Case Side Seal Ring 9 Shaft Side Seal Ring 10 Case Side Seal Ring 21 Heating Means 22 Heating Jacket 31 Hydrostatic Mechanical Seal (Mechanical Seal)
42 Heating means 43 Cooling means 44 Cooling jacket 47 Heat insulating material A Sealed fluid region A1 Sealed fluid end region B Atmospheric region C Intermediate region D Sealed fluid region D1 Sealed fluid end region E Atmospheric region F1 Heating fluid F2 Cooling fluid

Claims (9)

A shaft seal device configured to seal a sealed fluid region, which is a liquid region, with a mechanical seal including a case-side seal ring provided on a seal case and a shaft-side seal ring provided on a rotary shaft,
A shaft provided with a heating means for vaporizing the liquid in the sealed fluid region in the sealed fluid end region facing both sealed end surfaces, which are opposite end surfaces of both sealed rings of the mechanical seal in the sealed fluid region. Sealing device.   A non-contact type mechanical structure in which the mechanical seal is configured to form a dynamic pressure generating groove on one of both sealed end faces, and to hold the sealed end faces in a non-contact state by generating dynamic pressure therebetween. The shaft seal device according to claim 1, wherein the shaft seal device is a seal.   The mechanical seal forms a static pressure generating groove on one of both sealed end faces, and supplies both the sealed end faces to the static pressure generating groove by supplying a high-pressure seal gas from the sealed fluid region. The shaft seal device according to claim 1, wherein the shaft seal device is a non-contact type mechanical seal configured to be held in a non-contact state by generating a static pressure therebetween.   A second mechanical seal is provided closer to the atmosphere region than the mechanical seal, and a buffer gas is supplied to an intermediate region closed by the mechanical seal and the second mechanical seal. The shaft seal device according to claim 1, wherein the region and the atmospheric region are configured to be sealed through an intermediate region.   The two mechanical seals each include a case-side sealing ring provided on the seal case and a shaft-side sealing ring provided on the rotating shaft, and are formed on one of the two sealing end faces that are opposite end faces of the two sealing rings. 5. A non-contact type mechanical seal configured to generate a dynamic pressure between both sealed end faces by a pressure generating groove so as to keep the sealed end faces in a non-contact state. The shaft seal device described in 1.   6. The heating means according to claim 1, wherein a hollow heating jacket is provided on an inner periphery of the seal case, and a heating fluid is supplied into the heating jacket. The shaft seal device described in 1.   Cooling means for preventing the liquid in the sealed fluid region from being vaporized by the heating means is provided in the sealed fluid end region near the heating means and opposite to the mechanical seal across the heating means. The shaft seal device according to any one of claims 1 to 6, wherein   8. The cooling means according to claim 7, wherein a cooling jacket adjacent to the heating jacket is provided on an inner periphery of a seal case, and cooling fluid is supplied into the cooling jacket. A shaft seal device to be described.   The shaft seal device according to claim 8, wherein a heat insulating material is loaded between the heating jacket and the cooling jacket.

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