JP5138662B2 - Steam compressor - Google Patents

Description

  The present invention relates to a steam compressor.

  2. Description of the Related Art Conventionally, there is known a steam compressor that compresses a steam sucked into a steam chamber while sending the steam downstream by a rotating screw rotor (for example, see Patent Document 1 below).

  In the steam compressor disclosed in Patent Document 1, a steam chamber and two bearing shaft sealing spaces are provided in a casing. The two bearing shaft sealing spaces are arranged separately on the upper side and the lower side of the steam chamber in the steam feeding direction by the screw rotor. The housing is provided with a suction channel for introducing steam into the steam chamber at a position corresponding to the upper end of the steam chamber. A rotor shaft of a screw rotor is inserted into each bearing shaft sealing space.

  A bearing for supporting the rotor shaft is provided in the bearing shaft sealing space on the upper side. Further, two lip seals are provided in a region located on the steam chamber side with respect to the bearing in the upper bearing shaft seal space. One of the two lip seals is provided in a direction to prevent the outflow of steam from the steam chamber to the upper bearing shaft seal space, and is disposed at the end of the upper bearing shaft seal space on the steam chamber side. ing. The other of the two lip seals is disposed at a position between the bearing and the one lip seal in the bearing shaft seal space on the upper side. The other lip seal is provided in such a direction as to prevent the lubricating oil filled in the bearing from flowing to the steam chamber side. The housing is provided with an open flow path that allows the region between the two lip seals of the bearing shaft seal space on the upper side to communicate with the external atmospheric space.

  The lower bearing shaft seal space is provided with a bearing that supports the rotor shaft in the same manner as the upper bearing shaft seal space. Further, a labyrinth seal for suppressing the outflow of steam from the steam chamber to the lower-side shaft seal space or a bearing in a region located on the steam chamber side with respect to the bearing in the lower-side bearing shaft seal space, A lip seal is provided for preventing grease from flowing from the steam chamber side.

  By the way, there is a case where steam having a pressure lower than the atmospheric pressure is sucked into the steam chamber of such a steam compressor through the suction passage. In this case, the pressure at the upstream end of the steam chamber to which the suction flow path is connected is lower than atmospheric pressure. On the other hand, in the upper bearing shaft seal space, the region between the two lip seals communicates with the atmospheric space through the open flow path, so that the pressure in the region becomes equal to the atmospheric pressure. That is, when steam having a pressure lower than atmospheric pressure is sucked into the steam chamber, the pressure in the region between the two lip seals is higher than the pressure at the upstream end of the steam chamber. In this case, due to the pressure difference between the region between the two lip seals in the upper bearing shaft seal space and the upstream end of the steam chamber, air flows from the region into the steam chamber, There is a risk that air (air) may be mixed into the compressed steam. The region and the upstream end of the steam chamber are partitioned by the one lip seal, and this lip seal causes the steam to flow from the steam chamber to the bearing shaft seal space on the upper side. Therefore, it is difficult to suppress air from flowing into the steam chamber from the upper bearing shaft seal space.

  Therefore, in Patent Document 2 below, even when steam having a pressure lower than atmospheric pressure is sucked into the steam chamber, steam compression that can be applied to prevent the atmosphere (air) from being mixed into the steam compressed in the steam chamber. The structure of the machine is disclosed.

  In the steam compressor disclosed in Patent Document 2, a plurality of labyrinth seals are provided at intervals in the axial direction in a region between the steam chamber and the bearing of the rotor shaft in the housing. And in this steam compressor, the supply path is provided so that it may connect with the space between the two labyrinth seals near the steam chamber from the pipe connected to the discharge port of the steam chamber. That is, in this steam compressor, after being compressed in the steam chamber, a part of the steam discharged from the steam chamber can be introduced into the space between the two labyrinth seals, and the pressure in the space can be made relatively high. It is like that.

  If this configuration is applied to a region located closer to the steam chamber with respect to the connection part of the open channel in the bearing shaft seal space on the upper side of Patent Document 1, the region where the atmosphere is introduced through the open channel and the steam Since an area filled with high-pressure steam can be formed between the upstream end of the chamber and steam at a pressure lower than atmospheric pressure is sucked into the upstream end of the steam chamber through the suction channel. Even in this case, it is possible to prevent the air introduced into the bearing shaft sealing space on the upper side through the open flow path from flowing into the steam chamber.

JP 2008-19631 A JP 2008-57452 A

  However, the compressed steam discharged from the steam chamber through the discharge port should be supplied to the steam utilization device and effectively used. Nevertheless, the use of the steam discharged from the steam chamber to prevent the inflow of air into the steam chamber reduces the proportion of the steam that can be effectively used in the generated compressed steam. If it sees from the viewpoint, it will lead to the fall of the production efficiency of compressed steam.

  The present invention has been made to solve the above-described problem, and its object is to suppress a decrease in the generation efficiency of compressed steam while the pressure of the steam sucked into the steam chamber is lower than the atmospheric pressure. However, it is to provide a steam compressor capable of preventing the atmosphere from flowing into the steam chamber.

In order to achieve the above object, a steam compressor according to the present invention comprises a steam chamber provided with a steam inlet on one side in the longitudinal direction and a steam outlet on the other side in the longitudinal direction, and the steam A suction side shaft sealing chamber that communicates with the steam suction side of the chamber, a discharge side shaft sealing chamber that communicates with the steam discharge side of the steam chamber, and an open air path that connects the suction side shaft sealing chamber and the atmospheric space A compressor part accommodated in the steam chamber, and a rotor shaft extending from the compression part through the shaft sealing chambers on both sides thereof, and the compression part is rotated by rotating around the axis. A compression rotor that compresses the steam sucked into the steam chamber while sending the steam to the discharge port side, and is disposed at a position spaced apart from the connection portion of the atmosphere opening path to the steam chamber side in the suction side shaft seal chamber. In order to prevent the steam in the steam chamber from flowing into the open air path The first seal portion and the suction side shaft seal chamber are disposed at a position between the connection portion of the atmosphere open path and the first seal portion to suppress the flow of steam to the atmosphere open path. The second seal part, and a non-contact third seal part disposed in the discharge side shaft seal chamber for increasing the flow resistance against the steam leaking from the steam chamber to the discharge side shaft seal chamber, A region located between the first seal portion and the second seal portion in the suction side shaft seal chamber, and on the opposite side of the steam chamber with respect to the third seal portion in the discharge side shaft seal chamber. A communication portion that communicates with a region that is positioned; and a pressure control valve connected to the communication portion , wherein the first seal portion includes an inner screw portion through which the rotor shaft is inserted, A gap is formed between the inner peripheral surface of the screw portion and the outer peripheral surface of the rotor shaft. Ri seal portion der contactless provided to the pressure regulating valve, the communication from a region located on the opposite side of the steam chamber relative to the third sealing portion of the discharge-side shaft sealing chamber When the pressure of the steam flowing through the part is equal to or higher than a predetermined set pressure higher than the atmospheric pressure, it is located between the first seal part and the second seal part in the suction side shaft sealing chamber from the communication part. The pressure of the steam introduced into the region can be maintained at the set pressure .

In this steam compressor, the third seal portion provided in the discharge-side shaft seal chamber is non-contact type, so that the high-pressure steam after being compressed in the steam chamber is the third seal in the discharge-side shaft seal chamber. It leaks slightly in the region located on the opposite side of the steam chamber from the part. In this steam compressor, the region located between the first seal portion and the second seal portion disposed on the steam chamber side with respect to the connection portion of the air release path in the suction side shaft seal chamber and the discharge side A region located on the opposite side of the steam chamber from the steam seal chamber in the shaft seal chamber is communicated by the communicating portion, so that the steam seal chamber is located on the opposite side of the steam chamber from the third seal portion. The high-pressure steam leaked into the region is introduced into the region located between the first seal portion and the second seal portion in the suction side shaft seal chamber through the communication portion, and is held by both seal portions. As a result, high-pressure steam is filled between the connection portion of the atmosphere opening path to the suction-side shaft sealing chamber and the steam suction-side portion of the steam chamber, and the pressure is increased between the first seal portion and the second seal on both sides. A space held by the seal portion is formed. For this reason, even when steam having a pressure lower than atmospheric pressure is sucked into the steam chamber through the suction port, the air sucked into the suction-side shaft sealing chamber through the atmosphere open path is transferred to the steam chamber by the space held at the high pressure. Inflow can be prevented. By the way, a non-contact type seal portion such as a labyrinth seal used in a conventional steam compressor is provided in the discharge side shaft sealing chamber so that the compressed steam flows out from the steam chamber to the discharge side shaft sealing chamber. In the case of suppression, it is difficult to completely stop the leakage of steam from the steam chamber to the discharge side shaft sealing chamber with the non-contact type seal portion, and the steam slightly leaks to the discharge side shaft sealing chamber. On the other hand, in the steam compressor of the present invention, the first seal portion of the suction-side shaft seal chamber allows the steam leaked from the steam chamber to the discharge-side shaft seal chamber through the gap formed by the non-contact type third seal portion. It can be used to prevent the air introduced into the suction-side shaft sealing chamber from flowing into the steam chamber through the atmosphere opening path. That is, it is possible to prevent the atmosphere from flowing into the steam chamber by using the steam that was originally leaked from the steam chamber to the discharge side shaft seal chamber. As a result, in this steam compressor, it is not necessary to allocate a part of the steam discharged from the discharge outlet of the steam chamber in order to prevent air from flowing into the steam chamber. It can suppress that the ratio of the vapor | steam which can be utilized reduces. Therefore, in this steam compressor, it is possible to prevent the atmosphere from flowing into the steam chamber even when the pressure of the steam sucked into the steam chamber is lower than the atmospheric pressure while suppressing a decrease in the generation efficiency of the compressed steam. Can do. Further, the pressure of the steam compressed by the compression unit in the steam chamber and sent to the discharge side may vary or may not be a constant pressure. In that case, the pressure of the steam leaking from the steam chamber to the region located on the opposite side of the steam chamber with respect to the third seal portion in the discharge side shaft seal chamber changes. On the other hand, in this steam compressor, the pressure control valve connected to the communication portion flows from the region located on the opposite side of the steam chamber to the third seal portion in the discharge side shaft sealing chamber to the communication portion. When the pressure of the steam is equal to or higher than a predetermined set pressure higher than the atmospheric pressure, the steam introduced from the communication portion to the region located between the first seal portion and the second seal portion in the suction side shaft seal chamber Since the pressure can be maintained at the set pressure, the pressure of the steam leaking to the region located on the opposite side of the steam chamber with respect to the third seal portion in the discharge side shaft seal chamber has changed at a pressure equal to or higher than the set pressure. However, the pressure in the region between the first seal portion and the second seal portion of the suction side shaft sealing chamber can be stably maintained at a constant pressure (set pressure) higher than the atmospheric pressure.

  In the steam compressor, the casing is provided with an oil chamber that communicates with the suction-side shaft sealing chamber and accommodates lubricating oil, and the connection to the atmosphere opening path in the suction-side shaft sealing chamber is provided. The position closer to the oil chamber than the portion contacts the outer peripheral surface of the rotor shaft in a posture that prevents the lubricating oil flowing out from the oil chamber from flowing toward the steam chamber side in the suction side shaft seal chamber. There may be provided a lip seal having a lip portion.

  In a lip seal having a lip portion provided so as to contact the outer peripheral surface of the rotor shaft in a posture to prevent the lubricating oil flowing out from the oil chamber from flowing toward the steam chamber side in the suction side shaft seal chamber, If the space located on the steam chamber side of the lip seal becomes lower than the space located on the oil chamber side of the lip seal due to the suction of steam at a pressure lower than atmospheric pressure, the pressure difference between the two spaces Thus, the lip portion is strongly pressed against the outer peripheral surface of the rotor shaft. If the compression rotor rotates in this state for a long time, the lip portion will be worn out. Finally, the sealing effect of the lip seal is impaired and the lubricating oil flowing out of the oil chamber is lost. May flow to the side. On the other hand, in this configuration, since a space higher than the atmospheric pressure held by the first seal portion and the second seal portion is formed between the lip seal and the steam chamber, the steam chamber Even when low-pressure steam is sucked, it is possible to prevent the space located on the steam chamber side of the lip seal from becoming lower than the space located on the oil chamber side of the lip seal. For this reason, it can prevent that a lip part is strongly pressed on the outer peripheral surface of a rotor shaft, As a result, it can suppress that the wear of a lip part becomes intense. Then, it is possible to prevent the lubricating oil that has flowed out of the oil chamber due to wear of the lip portion from flowing into the steam chamber and entering the steam chamber.

In the steam compressor , the communication portion includes a drain tank for separating liquid contained in steam flowing from the discharge side shaft sealing chamber to the suction side shaft sealing chamber, and the pressure control valve includes the drain It is preferable to maintain the pressure of the vapor from which the liquid is separated in the tank at the set pressure.

  The steam leaking from the steam chamber to the discharge-side shaft sealing chamber is introduced into the steam chamber for sealing or lubrication between, for example, condensate generated by cooling of the steam or the compression portion of the compression rotor and the inner surface of the steam chamber. May be included. When such liquid flows into the pressure control valve together with the vapor, the operation of the pressure control valve may become unstable. In contrast, in this configuration, the communication portion has a drain tank for separating the liquid contained in the vapor flowing from the discharge side shaft sealing chamber to the suction side shaft sealing chamber, and the pressure control valve is provided in the drain tank. The vapor pressure from which the liquid is separated is maintained at the set pressure. For this reason, even when the liquid leaked from the steam chamber to the discharge-side shaft sealing chamber contains liquid, it is possible to prevent the liquid from flowing into the pressure control valve. As a result, it is possible to prevent the operation of the pressure control valve from becoming unstable.

In the case of this, the drain tank drainage path for discharging liquid accumulated in the drain tank are connected, the drain discharge path is preferably connected to the inlet.

  If comprised in this way, the liquid collected in the drain tank can be returned to a vapor | steam chamber through a drain discharge channel. Thereby, the liquid leaking from the steam chamber to the discharge side shaft seal chamber and the condensate generated by the temperature drop of the steam leaking to the discharge side shaft seal chamber can be reused. As a result, a decrease in energy efficiency in vapor compression can be suppressed.

In the steam compressor , a surplus steam discharge path is connected to the pressure control valve, and the pressure control valve is connected to the surplus steam discharge path when the pressure of the steam in the communication portion exceeds the set pressure. Preferably, the surplus steam discharge path is connected to the suction port.

  If comprised in this way, the excess steam discharged | emitted from a pressure control valve can be returned to a steam chamber through a surplus steam discharge channel. For this reason, the steam discharged from the pressure control valve can be reused. As a result, a decrease in energy efficiency in vapor compression can be suppressed.

  In the above-described steam compressor, the steam compressor includes a drive source that rotates the compression rotor and a control unit that controls driving of the drive source, and the communication unit includes a connection path provided with an on-off valve. Preferably, the controller is connected to a steam pipe through which steam having a pressure higher than atmospheric pressure flows, and the control unit opens the open / close valve in accordance with the activation of the drive source.

  When the drive source is started, that is, when the steam compressor is started, the pressure in the region on the discharge side of the steam chamber is not increased because the steam is not yet compressed in the steam chamber. For this reason, when the steam compressor is started, steam having a pressure higher than atmospheric pressure may not leak from the steam chamber to the discharge side shaft seal chamber. On the other hand, in this configuration, the communication unit is connected to the steam pipe through which steam having a pressure higher than atmospheric pressure flows through the connection path provided with the on-off valve, and the control unit activates the drive source. Accordingly, since the on-off valve is opened, steam having a pressure higher than atmospheric pressure can be introduced from the steam pipe to the communicating portion through the connection path when the steam compressor is started. For this reason, even when steam having a pressure higher than atmospheric pressure does not leak from the steam chamber to the discharge-side shaft sealing chamber when the steam compressor is started, the space between the first seal portion and the second seal portion of the suction-side shaft sealing chamber It is possible to supply steam at a pressure higher than atmospheric pressure to the region, and to maintain the pressure in that region higher than atmospheric pressure.

  As described above, according to the present invention, the atmosphere enters the steam chamber even when the pressure of the steam sucked into the steam chamber is lower than the atmospheric pressure while suppressing the decrease in the generation efficiency of the compressed steam. Can be prevented.

It is a schematic diagram which shows roughly the structure of the vapor compressor by the reference example of this invention. It is a mimetic diagram showing roughly the composition of the steam compressor by a 1st embodiment of the present invention. It is a mimetic diagram showing roughly the composition of the steam compressor by a 2nd embodiment of the present invention. It is a mimetic diagram showing roughly the composition of the steam compressor by a 3rd embodiment of the present invention. It is a schematic diagram which shows roughly the structure of the steam compressor by 4th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

( Reference example )
First, with reference to FIG. 1, the structure of the steam compressor by the reference example of this invention is demonstrated.

The steam compressor according to this reference example compresses the steam sucked into the steam chamber 32 provided inside the casing 4 while sending it to the downstream side by the rotating compression rotor 2.

Specifically, the steam compressor according to this reference example includes a compression rotor 2, a drive source 3, a housing 4, a suction side bearing 6, a first suction side seal portion 10, and a second suction side seal. Portion 12, third suction side seal portion 14, discharge side bearing 15, first discharge side seal portion 16, second discharge side seal portion 18, third discharge side seal portion 20, and communication portion 22. It has.

  The compression rotor 2 is rotatably provided in the housing 4, and compresses the water vapor sucked into a steam chamber 32 (described later) in the housing 4 while sending it to the discharge port 34 (described later). The compression rotor 2 has a compression portion 2a and a rotor shaft 2b. Although not shown, the compression unit 2a is formed in a screw shape and is accommodated in a steam chamber 32 described later. The rotor shaft 2b extends from the compression portion 2a on both sides in the axial direction through shaft sealing chambers 35 and 39, bearing installation chambers 36 and 40, and oil chambers 37 and 41, which will be described later. A drive source 3 is connected to one end of the rotor shaft 2b. The driving source 3 rotates the compression rotor 2 around the axis by applying a driving force to the rotor shaft 2b. Then, when the compression rotor 2 rotates about the axis, the compression section 2a rotates in the steam chamber 32, and the compression section 2a sends the water vapor sucked into the steam chamber 32 to the discharge port 34 described later. While compressing.

  The casing 4 is configured in a cylindrical shape, and includes a steam chamber 32, a suction port 33, a discharge port 34, a suction side shaft sealing chamber 35, a suction side bearing installation chamber 36, and a suction side oil chamber 37. , A suction-side atmosphere opening path 38, a discharge-side shaft sealing chamber 39, a discharge-side bearing installation chamber 40, a discharge-side oil chamber 41, and a discharge-side atmosphere opening path 42.

  The steam chamber 32 is a space where water vapor is sucked and the water vapor is compressed by the compression unit 2a. The steam chamber 32 is provided inside the housing 4 so as to extend in the longitudinal direction of the housing 4 (the axial direction of the rotor shaft 2b).

  A suction port 33 for sucking water vapor into the steam chamber 32 is provided at a position corresponding to one end of the steam chamber 32 in the longitudinal direction of the housing 4. The suction port 33 extends in the radial direction of the housing 4 and is connected to the steam chamber 32 from the side. A suction side steam pipe (not shown) is connected to the suction port 33. Water vapor supplied from the suction side steam pipe is sucked into the steam chamber 32 through the suction port 33.

  Further, a discharge port 34 for discharging the compressed water vapor from the steam chamber 32 is provided at a position corresponding to the other end portion in the longitudinal direction of the steam chamber 32 in the housing 4. The discharge port 34 extends in the radial direction of the housing 4 and is connected to the steam chamber 32 from the side. A discharge side steam pipe (not shown) is connected to the discharge port 34. The water vapor discharged from the steam chamber 32 to the discharge side steam pipe through the discharge port 34 is supplied to a steam utilization device such as a heat exchanger through the discharge side steam pipe.

  The suction side shaft sealing chamber 35 is provided so as to communicate with the end of the steam chamber 32 on the suction side of water vapor. The suction side shaft sealing chamber 35 extends in the axial direction of the housing 4. A portion of the rotor shaft 2 b of the compression rotor 2 that extends from the compression portion 2 a to one side is inserted into the suction side shaft sealing chamber 35. In the suction side shaft sealing chamber 35, the space around the rotor shaft 2 b is sealed by the suction side seal portions 10, 12, and 14.

  The suction side bearing installation chamber 36 is a space in which the suction side bearing 6 is installed. The suction side bearing installation chamber 36 is provided at a position opposite to the steam chamber 32 with respect to the suction side shaft sealing chamber 35 in the axial direction of the housing 4, and communicates with the suction side shaft sealing chamber 35. .

  The suction side oil chamber 37 is a space in which lubricating oil to be supplied to the suction side bearing 6 is accommodated. The suction side oil chamber 37 is included in the concept of the oil chamber of the present invention. The suction side oil chamber 37 is provided at a position opposite to the suction side shaft sealing chamber 35 with respect to the suction side bearing installation chamber 36 in the axial direction of the housing 4, and communicates with the suction side bearing installation chamber 36. Yes. That is, the suction side oil chamber 37 communicates with the suction side shaft sealing chamber 35 via the suction side bearing installation chamber 36.

  The suction-side atmosphere opening path 38 is for communicating the suction-side shaft sealing chamber 35 with the atmosphere space outside the housing 4. The suction side air opening path 38 is included in the concept of the air opening path of the present invention. The suction-side air release path 38 is provided in the housing 4 so as to extend radially outward from the axial intermediate portion of the suction-side shaft sealing chamber 35.

  The discharge-side shaft sealing chamber 39, the discharge-side bearing installation chamber 40, the discharge-side oil chamber 41, and the discharge-side atmosphere opening path 42 are disposed on the steam-side discharge side of the steam chamber 32. The discharge-side shaft sealing chamber 39, the discharge-side bearing installation chamber 40, the discharge-side oil chamber 41, and the discharge-side air release path 42 are arranged in the axial direction of the housing 4 with respect to the suction-side shaft sealing chamber 35, the suction-side bearing installation chamber 36, The suction side oil chamber 37 and the suction side air release path 38 are arranged symmetrically. The configurations of the discharge side shaft sealing chamber 39, the discharge side bearing installation chamber 40, the discharge side oil chamber 41, and the discharge side atmosphere opening path 42 are the suction side shaft sealing chamber 35, the suction side bearing installation chamber 36, the suction side oil chamber 37, and the like. The configuration is basically the same as that of the suction-side atmosphere opening path 38.

  The suction side bearing 6 is installed in the suction side bearing installation chamber 36, and rotatably supports the rotor shaft 2b.

  The first suction-side seal portion 10 is disposed at a position in the suction-side shaft sealing chamber 35 that is separated from the connection portion of the suction-side atmosphere opening path 38 toward the steam chamber 32. Specifically, the first suction side seal portion 10 is disposed at the end of the suction side shaft sealing chamber 35 on the steam chamber 32 side. The first suction side seal portion 10 is a non-contact type seal portion for suppressing the water vapor in the steam chamber 32 from leaking to the suction side atmosphere opening path 38, and is based on the concept of the first seal portion of the present invention. It is included. The first suction side seal portion 10 is formed of, for example, a so-called visco seal. The Bisco seal has an unillustrated inner screw portion provided on the inner surface of the housing 4 forming the suction side shaft sealing chamber 35, and the rotor shaft 2b is inserted through the inner screw portion. The inner screw portion has an inner diameter that is slightly larger than the outer diameter of the rotor shaft 2b, and the inner screw portion is entangled between a plurality of screw threads on the inner peripheral surface of the inner screw portion and the outer peripheral surface of the rotor shaft 2b. A small gap with an elliptical shape is formed. Since this gap has a high flow resistance of water vapor due to its complicated shape, the water vapor in the steam chamber 32 is substantially prevented from leaking to the suction side shaft sealing chamber 35.

  The second suction side seal portion 12 is disposed at a position between the connection portion of the suction side air release path 38 and the first suction side seal portion 10 in the suction side shaft sealing chamber 35. The second suction side seal portion 12 is a non-contact type seal portion for suppressing the flow of water vapor toward the connection site side of the suction side atmosphere opening path 38 along the rotor shaft 2b. It is included in the concept of a seal part. The second suction side seal portion 12 is formed of, for example, a visco seal similar to the first suction side seal portion 10.

  The third suction-side seal portion 14 is disposed in a position closer to the suction-side oil chamber 37 (suction-side bearing installation chamber 36) than the connection portion of the suction-side atmosphere opening path 38 in the suction-side shaft sealing chamber 35. . The third suction-side seal portion 14 flows from the suction-side oil chamber 37 into the suction-side shaft sealing chamber 35 through the suction-side bearing installation chamber 36, and the lubricating oil flows into the steam chamber 32 side in the suction-side shaft sealing chamber 35. It is a contact type seal part which prevents flowing toward.

  Specifically, the third suction side seal portion 14 is formed of a lip seal. The lip seal has a main body portion 14a and a lip portion 14b. The main body portion 14 a is an annular portion fitted into the suction side shaft sealing chamber 35. The lip portion 14b extends radially inward from the inner peripheral surface of the main body portion 14a. The lip portion 14b prevents the lubricating oil flowing from the suction-side oil chamber 37 through the suction-side bearing installation chamber 36 into the suction-side shaft sealing chamber 35 from flowing toward the steam chamber 32, and thus the rotor shaft 2b. It is in contact with the outer peripheral surface. In other words, the lip portion 14b gradually goes to the suction side oil chamber 37 side toward the radially inner edge, and radially ends in the curved state so as to be convex toward the steam chamber 32 side. The portion is in contact with the outer peripheral surface of the rotor shaft 2b. The lip portion 14b generates an elastic force by being curved, and the edge portion on the radially inner side of the lip portion 14b is pressed against the outer peripheral surface of the rotor shaft 2b by the elastic force.

  The discharge side bearing 15 is provided in the discharge side bearing installation chamber 40, and rotatably supports the rotor shaft 2b.

  The first discharge side seal portion 16, the second discharge side seal portion 18 and the third discharge side seal portion 20 are disposed in the discharge side shaft sealing chamber 39, and the axial direction of the casing 4 (the axis of the rotor shaft 2b). The first suction side seal part 10, the second suction side seal part 12 and the third suction side seal part 14 are arranged in the direction). The configurations of the first discharge side seal portion 16, the second discharge side seal portion 18 and the third discharge side seal portion 20 are the same as the first suction side seal portion 10, the second suction side seal portion 12 and the third suction side seal portion. This is the same as the configuration of FIG. The first discharge-side seal portion 16 is a non-contact seal portion for increasing the flow resistance against water vapor leaking from the steam chamber 32 along the rotor shaft 2b to the discharge-side shaft seal chamber 39. This is included in the concept of the third seal portion.

  The communication portion 22 includes a region located between the first suction side seal portion 10 and the second suction side seal portion 12 in the suction side shaft seal chamber 35 and a first discharge side seal in the discharge side shaft seal chamber 39. A region (a region located between the first discharge side seal portion 16 and the second discharge side seal portion 18) located on the opposite side of the steam chamber 32 with respect to the portion 16 is communicated. The water vapor leaked from the steam chamber 32 to the region between the first discharge side seal portion 16 and the second discharge side seal portion 18 of the discharge side shaft seal chamber 39 is connected to the first side of the suction side shaft seal chamber 35 through the communication portion 22. It is introduced into a region between the suction side seal portion 10 and the second suction side seal portion 12.

  Specifically, the communication portion 22 includes a suction side flow path 22a, a discharge side flow path 22b, and a communication path 22c.

  The suction-side flow path 22a is provided in the housing 4 and is radially outward from the region located between the first suction-side seal portion 10 and the second suction-side seal portion 12 in the suction-side shaft sealing chamber 35. It extends to.

  The discharge side flow path 22b is provided in the housing 4 and is radially outward from the region located between the first discharge side seal portion 16 and the second discharge side seal portion 18 in the discharge side shaft sealing chamber 39. It extends to.

  The communication path 22c connects the suction side flow path 22a and the discharge side flow path 22b to each other, and includes a pipe that connects the flow paths 22a and 22b.

Next, the operation of the steam compressor according to this reference example will be described.

In the steam compressor according to this reference example , water vapor is supplied from a suction side steam pipe (not shown) to the suction port 33, and the water vapor is sucked into the steam chamber 32 from the suction port 33. The compression rotor 2 rotates when a driving force is applied from the driving source 3, and thereby compresses the water vapor while the compression unit 2 a rotates in the steam chamber 32. At this time, the compressing unit 2 a compresses the water vapor sucked into the steam chamber 32 from the suction port 33 while sending it to the discharge port 34 side. The water vapor thus compressed is discharged from the vapor chamber 32 through the discharge port 34 to a discharge side steam pipe (not shown).

  Then, because the first discharge side seal portion 16 is a non-contact type seal portion, the first discharge side seal portion 16 and the first discharge side seal portion 16 of the discharge side shaft seal chamber 39 are connected to the first end from the discharge side end of the steam chamber 32. The compressed water vapor slightly leaks into the region between the two discharge side seal portions 18. The leaked water vapor passes between the first suction side seal part 10 and the second suction side seal part 12 of the suction side shaft sealing chamber 35 through the discharge side flow path 22b, the communication path 22c, and the suction side flow path 22a of the communication part 22. Introduced in the area. As a result, the space between the first suction side seal portion 10 and the second suction side seal portion 12 is filled with relatively high-pressure water vapor, and the vapor pressure in the space is substantially held by the seal portions 10 and 12 on both sides. Is done. That is, the space between the seal parts 10 and 12 is higher than the atmospheric pressure.

  By the way, in some cases, water vapor having a pressure lower than the atmospheric pressure is supplied from the suction side steam pipe to the suction port 33. In this case, the pressure at the end of the vapor chamber 32 on the suction side is lower than atmospheric pressure. In this case, if the high-pressure space held by the first suction side seal portion 10 and the second suction side seal portion 12 is not formed in the suction side shaft sealing chamber 35, the suction side through the suction side air release path 38 is used. The atmosphere (air) introduced into the shaft seal chamber 35 flows into the steam chamber 32.

In this reference example , as described above, the region between the first suction side seal portion 10 and the second suction side seal portion 12, the region between the first discharge side seal portion 16 and the second discharge side seal portion 18, and Are communicated by the communication part 22, high-pressure steam is filled between the connection part of the suction-side atmosphere opening path 38 to the suction-side shaft sealing chamber 35 and the steam-suction-side end part of the steam chamber 32, In addition, a space is formed in which the vapor pressure is held by the first suction side seal portion 10 and the second suction side seal portion 12 on both sides. For this reason, even when water vapor having a pressure lower than the atmospheric pressure is sucked into the steam chamber 32 through the suction port 33, the steam is introduced into the suction-side shaft sealing chamber 35 through the suction-side atmosphere opening path 38 by the space held at the high pressure. It is possible to prevent the atmospheric air from flowing into the steam chamber 32.

Further, in this reference example , the steam leaked from the steam chamber 32 to the discharge side shaft sealing chamber 39 through the gap formed by the non-contact type first discharge side seal portion 16 is first suction side of the suction side shaft sealing chamber 35. In order to prevent the air introduced into the suction-side shaft sealing chamber 35 through the suction-side atmosphere opening path 38 from flowing into the steam chamber 32 by being introduced into the region between the seal portion 10 and the second suction-side seal portion 12. Can be used. That is, it is possible to prevent the atmosphere from flowing into the steam chamber 32 using the steam that was originally leaked from the steam chamber 32 to the discharge side shaft sealing chamber 39 in vain. As a result, in this reference example , it is not necessary to allocate a part of the steam discharged from the discharge port 34 of the steam chamber 32 in order to prevent the atmosphere from flowing into the steam chamber 32. It can suppress that the ratio of the steam which can be utilized effectively among them decreases. Therefore, in this reference example , while suppressing a decrease in the generation efficiency of the compressed steam, the atmosphere is prevented from flowing into the steam chamber 32 even when the pressure of the steam sucked into the steam chamber 32 is lower than the atmospheric pressure. be able to.

Further, in this reference example , in the suction side shaft sealing chamber 35, the lubricating oil flowing out from the suction side oil chamber 37 is located at a position closer to the suction side oil chamber 37 than the connection portion of the suction side air release path 38. A third suction-side seal portion 14 having a lip portion 14b that comes into contact with the outer peripheral surface of the rotor shaft 2b in a posture that prevents the flow toward the steam chamber 32 side in the shaft seal chamber 35 is provided.

In such a third suction side seal portion 14, when the space located on the steam chamber 32 side of the seal portion 14 is at a lower pressure than the space located on the suction side oil chamber 37 side of the seal portion 14, both these spaces are used. The lip portion 14b is strongly pressed against the outer peripheral surface of the rotor shaft 2b by the pressure difference. If the compression rotor 2 is rotated for a long time in this state, the lip portion 14b is severely worn, and finally, the sealing effect by the lip portion 14b is impaired and the lubricating oil flowing out from the suction side oil chamber 37 is lost. There is a risk that oil flows to the steam chamber 32 side. On the other hand, in this reference example , the pressure is higher than the atmospheric pressure held by the first suction side seal portion 10 and the second suction side seal portion 12 between the third suction side seal portion 14 and the steam chamber 32. Since the space is formed, even when water vapor having a pressure lower than atmospheric pressure is sucked into the steam chamber 32, the space located on the steam chamber 32 side of the third suction side seal portion 14 is the suction side oil of the seal portion 14. It is possible to prevent the pressure from becoming lower than the space located on the chamber 37 side. For this reason, it can prevent that the lip | rip part 14b is strongly pressed on the outer peripheral surface of the rotor shaft 2b, As a result, it can suppress that the wear of the lip | rip part 14b becomes intense. Then, it is possible to prevent the lubricating oil flowing out from the suction side oil chamber 37 due to wear of the lip portion 14 b from flowing into the steam chamber 32 and entering the steam chamber 32.

(First Embodiment)
Next, the configuration of the steam compressor according to the first embodiment of the present invention will be described with reference to FIG.

The steam compressor according to the first embodiment includes a pressure control valve 52 connected to the communication unit 22. The pressure of the water vapor compressed by the compression unit 2a in the steam chamber 32 and sent to the discharge side may fluctuate or may not be constant, and in this case, the first pressure from the steam chamber 32 to the first shaft sealing chamber 39 in the discharge side may be. The pressure of the water vapor that leaks into the region between the discharge-side seal portion 16 and the second discharge-side seal portion 18 and flows to the communication portion 22 changes. In this case, the pressure control valve 52 is provided to maintain the pressure of the water vapor flowing through the communication portion 22 at a predetermined set pressure higher than the atmospheric pressure.

  Specifically, the pressure control valve 52 is connected to the communication path 22 c of the communication unit 22.

  When the pressure of the water vapor flowing from the region between the first discharge side seal portion 16 and the second discharge side seal portion 18 of the discharge side shaft sealing chamber 39 to the communication portion 22 is equal to or higher than the set pressure. Further, the pressure of the water vapor introduced from the communication portion 22 to the region between the first suction side seal portion 10 and the second suction side seal portion 12 of the suction side shaft sealing chamber 35 can be maintained at the set pressure. ing. The set pressure is determined by the pressure control valve 52. An excess steam discharge path 53 is connected to the pressure control valve 52. The pressure regulating valve 52 automatically discharges excess steam when the water vapor pressure in the region on the discharge side shaft seal chamber 39 side exceeds the set pressure with respect to the location where the pressure regulating valve 52 is provided in the communication portion 22. Excess water vapor is discharged to the channel 53. The pressure control valve 52 maintains the pressure of the water vapor flowing through the communication portion 22 at the set pressure by discharging the excess water vapor. At the time of steady operation of the steam compressor, the pressure of water vapor leaking from the steam chamber 32 to the region between the first discharge side seal portion 16 and the second discharge side seal portion 18 in the discharge side shaft seal chamber 39 is: Since the pressure is equal to or higher than the set pressure, the water vapor introduced into the region between the first suction side seal portion 10 and the second suction side seal portion 12 of the suction side shaft sealing chamber 35 from the communication portion 22 during the steady operation. The pressure is always maintained at the set pressure by the pressure control valve 52.

The other configuration of the steam compressor according to the first embodiment is the same as that of the steam compressor of the reference example .

As described above, in the first embodiment, the pressure adjustment valve 52 is connected to the communication portion 22, and the pressure adjustment valve 52 is connected to the first discharge side seal portion 16 of the discharge side shaft sealing chamber 39 and the first pressure seal valve 16. When the pressure of water vapor flowing from the region between the two discharge side seal portions 18 to the communication portion 22 is equal to or higher than a predetermined set pressure higher than the atmospheric pressure, the first suction of the suction side shaft sealing chamber 35 from the communication portion 22 is performed. The water vapor pressure introduced into the region between the side seal portion 10 and the second suction side seal portion 12 is configured to be able to maintain the set pressure. For this reason, the first discharge-side seal portion 16 and the second discharge-side seal portion 16 in the discharge-side shaft sealing chamber 39 are caused by fluctuations in the pressure of the water vapor that is compressed by the compression portion 2a in the steam chamber 32 and sent to the discharge side. Even if the pressure of the steam leaking into the region between the discharge side seal portions 18 changes by a pressure equal to or higher than the set pressure, the pressure in the region between the seal portions 10 and 12 of the suction side shaft sealing chamber 35 is set to be higher than the atmospheric pressure. It can be stably maintained at a high constant pressure.

The other effects of the first embodiment are the same as the effects of the reference example .

( Second Embodiment)
Next, with reference to FIG. 3, the structure of the steam compressor by 2nd Embodiment of this invention is demonstrated.

In the vapor compressor according to the second embodiment, the communication part 22 has a drain tank 54 for separating water contained in water vapor flowing from the discharge side shaft sealing chamber 39 to the suction side shaft sealing chamber 35 through the communication part 22. The pressure control valve 52 is configured to maintain the pressure of water vapor from which water has been separated by the drain tank 54 at a set pressure.

  Specifically, for the water vapor leaking from the steam chamber 32 to the region between the seal portions 16 and 18 of the discharge side shaft sealing chamber 39, for example, the inner peripheral surface of the housing 4 that forms the steam chamber 32 and the compression rotor 2. In some cases, water introduced into the steam chamber 32 for sealing and lubrication with the compression portion 2a is included. In addition, the water vapor leaked from the steam chamber 32 to the region between the seal portions 16 and 18 of the discharge side shaft seal chamber 39 may drop in temperature, thereby generating condensed water. Therefore, the water vapor flowing out from the discharge side shaft sealing chamber 39 to the discharge side flow path 22b may contain water. When water contained in such water vapor flows into the pressure control valve 52, the operation of the pressure control valve 52 may become unstable. For this reason, in the present embodiment, the pressure of the water vapor after the water is separated in the drain tank 54 is maintained at the set pressure by the pressure control valve 52.

Specifically, in the second embodiment, the drain tank 54 is provided in the communication passage 22 c of the communication portion 22, and the communication passage 22 c and the pressure control valve 52 are connected to the upper portion of the drain tank 54. A drain discharge path 56 for discharging the water accumulated in the drain tank 54 is connected to the bottom of the drain tank 54. A drain valve 58 is provided in the drain discharge path 56. The drain valve 58 discharges water accumulated in the drain tank 54 while keeping a space in the drain tank 54 in which water vapor is stored in a watertight state. That is, the drain valve 58 maintains a state in which water is interposed between the space in the drain tank 54 in which water vapor is stored and the atmospheric space connected to the space in the drain tank 54 through the drain discharge path 56. The water in the drain tank 54 is gradually discharged.

  Water vapor containing water flowing out from the discharge-side shaft sealing chamber 39 to the communication portion 22 is introduced into the drain tank 54 from its upper part. At this time, the water accumulates in the lower part of the drain tank 54 and is separated from the water vapor. The flow rate of water discharged from the drain tank 54 is such that the flow path diameter of the drain discharge path 56 is appropriately set, so that the water level accumulated in the drain tank 54 is changed to the communication path 22c and the pressure control valve 52 with respect to the drain tank 54. The flow rate is set so as to be maintained at a position lower than the connection site. As a result, the water vapor after the water is separated in the drain tank 54 is introduced into the region between the seal portions 10 and 12 in the suction side shaft sealing chamber 35 through the communication path 22c and the suction side flow path 22a. Further, the pressure control valve 52 is configured to maintain the water vapor pressure existing in the upper space in the drain tank 54 at the set pressure after the water is separated in the drain tank 54. If it exceeds, surplus steam will be discharged to the surplus steam discharge path 53.

Other configurations of the steam compressor according to the second embodiment are the same as those of the steam compressor according to the first embodiment.

As described above, in the second embodiment, the communication part 22 has the drain tank 54 for separating water contained in the water vapor flowing from the discharge side shaft sealing chamber 39 to the suction side shaft sealing chamber 35. The pressure control valve 52 maintains the pressure of the water vapor after the water is separated in the drain tank 54 at the set pressure. For this reason, even when water is contained in the water vapor leaked from the steam chamber 32 to the discharge side shaft sealing chamber 39, it is possible to prevent water from flowing into the pressure control valve 52. As a result, it is possible to prevent the operation of the pressure control valve 52 from becoming unstable.

The other effects of the second embodiment are the same as the effects of the reference example and the first embodiment.

( Third embodiment)
Next, with reference to FIG. 4, the structure of the steam compressor by 3rd Embodiment of this invention is demonstrated.

In the steam compressor according to the third embodiment, water vapor can be taken into the communicating portion 22 from the discharge side steam pipe 102 when the drive source 3 is started.

Specifically, the steam compressor according to the third embodiment includes a control unit 59 for controlling driving of the driving source 3 and other devices constituting the steam compressor. The steam compressor includes a connection path 60 and an on-off valve 62.

The connection path 60 connects a position higher than the maximum water level in the drain tank 54 of the communication unit 22 where water accumulates and the discharge side steam pipe 102 to each other. The on-off valve 62 is an electromagnetic valve that is controlled to be opened and closed by the control unit 59, and is provided in the connection path 60. That is, in the third embodiment, the communication part 22 is connected to the discharge side steam pipe 102 via the connection path 60 provided with the on-off valve 62. The discharge side steam pipe 102 is included in the concept of the steam pipe of the present invention.

  Then, the control unit 59 opens the closed on-off valve 62 with the activation of the drive source 3. Specifically, the steam compressor is provided with an unillustrated start switch. When the start switch is turned on, the control unit 59 starts driving the drive source 3 and opens the on-off valve 62 for a certain time. Steam at a pressure higher than atmospheric pressure flows in the discharge-side steam pipe 102, and the steam in the discharge-side steam pipe 102 is constant in the drain tank 54 through the connection path 60 by opening the on-off valve 62. Supplied on time. Thereby, after starting the steam compressor, steam having a pressure higher than the atmospheric pressure is introduced into the region between the seal portions 10 and 12 of the suction side shaft sealing chamber 35 for a certain period of time.

The other configurations of the steam compressor according to the third embodiment are the same as those of the steam compressor according to the second embodiment.

At the start of the steam compressor, since the steam is not yet compressed in the steam chamber 32, the pressure in the discharge side region of the steam chamber 32 is not increased. For this reason, when the steam compressor is started, steam having a pressure higher than atmospheric pressure may not leak from the steam chamber 32 to the discharge side shaft sealing chamber 39. In contrast, in the third embodiment, the communication unit 22 is connected to the discharge-side steam pipe 102 via the connection path 60 provided with the on-off valve 62, and the control unit 59 activates the drive source 3. Accordingly, since the on-off valve 62 is opened, water vapor having a pressure higher than atmospheric pressure can be introduced from the discharge-side steam pipe 102 to the communication portion 22 through the connection path 60 when the steam compressor is started. For this reason, even when steam having a pressure higher than atmospheric pressure does not leak from the steam chamber 32 to the discharge-side shaft seal chamber 39 when the steam compressor is started, the region between the seal portions 10 and 12 of the suction-side shaft seal chamber 35 Water vapor having a pressure higher than atmospheric pressure can be supplied to the gas, and the pressure in that region can be maintained at a pressure higher than atmospheric pressure.

The other effects of the third embodiment are the same as the effects of the reference example and the embodiments.

( Fourth embodiment)
Next, with reference to FIG. 5, the structure of the steam compressor by 4th Embodiment of this invention is demonstrated.

In the steam compressor according to the fourth embodiment, a drain discharge path 56 connected to the drain tank 54 and an excess steam discharge path 53 connected to the pressure control valve 52 are connected to the suction port 33.

  Since water vapor having a pressure higher than atmospheric pressure is introduced into the drain tank 54, the water accumulated in the drain tank 54 is discharged into the drain discharge path 56 at a pressure higher than atmospheric pressure. For this reason, when water vapor having a pressure lower than atmospheric pressure is supplied to the suction port 33 from an unillustrated suction side steam pipe, the pressure of the water discharged to the drain discharge path 56 is higher than the pressure in the suction port 33. Also gets higher. As a result, the water discharged to the drain discharge path 56 is easily sucked into the suction port 33 and introduced into the steam chamber 32 due to the pressure difference between the water and the suction port 33.

  Further, since the set pressure of the pressure control valve 52 is set to a pressure slightly higher than the atmospheric pressure, the pressure of the excess water vapor discharged from the pressure control valve 52 to the excess steam discharge path 53 is higher than the atmospheric pressure. Get higher. For this reason, when water vapor having a pressure lower than atmospheric pressure is supplied from the suction side steam pipe to the suction port 33, the pressure of the surplus steam discharged to the surplus steam discharge path 53 is higher than the pressure in the suction port 33. Also gets higher. As a result, surplus water vapor discharged to the surplus steam discharge path 53 is easily sucked into the suction port 33 and introduced into the steam chamber 32 due to a pressure difference between the steam and the suction port 33.

The other configuration of the steam compressor according to the fourth embodiment is the same as that of the steam compressor according to the third embodiment.

In the fourth embodiment, since the drain discharge path 56 connected to the drain tank 54 is connected to the suction port 33, the water accumulated in the drain tank 54 can be returned to the steam chamber 32 through the drain discharge path 56. Thereby, the water leaked from the steam chamber 32 to the discharge side shaft seal chamber 39 and the condensed water generated by the temperature drop of the water vapor leaked to the discharge side shaft seal chamber 39 can be reused. As a result, a decrease in energy efficiency in vapor compression can be suppressed.

Further, in the fourth embodiment, the surplus steam discharge path 53 through which surplus steam is discharged from the pressure control valve 52 is connected to the suction port 33, so that surplus steam discharged from the pressure control valve 52 is discharged from the surplus steam. It can be returned to the steam chamber 32 through the passage 53. For this reason, the water vapor discharged from the pressure control valve 52 can be reused. As a result, a decrease in energy efficiency in vapor compression can be further suppressed.

The effects of the fourth embodiment other than those described above are the same as the effects of the reference example and the embodiments described above.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes meanings equivalent to the scope of claims for patent and all modifications within the scope.

  For example, the first suction side seal portion 10, the second suction side seal portion 12, the first discharge side seal portion 16, and the second discharge side seal portion 18 may be non-contact type seal portions other than the Bisco seal. Good. For example, each of these seal portions 10, 12, 16, and 18 may be a known labyrinth seal.

Further, each of the seal portions 12, 16, 18 made of the Bisco seal may have an external screw portion provided on the outer peripheral surface of the rotor shaft 2b in place of the internal screw portion. That is, each of the seal portions 12, 16, and 18 has a shape in which the seal portion is inserted between the plurality of screw threads on the outer peripheral surface of the outer screw portion and the inner peripheral surface of the casing 4 that forms the shaft sealing chambers 35 and 39. It may be such that a minute gap is formed. As a reference example, the first suction side seal portion may be the same.

  Moreover, the 3rd suction | inhalation side seal part 14 and the 3rd discharge side seal part 20 may consist of contact-type seal parts other than a lip seal. For example, each of the seal portions 14 and 20 may be a known mechanical seal, various oil seals, a gland packing, or the like.

In the third embodiment, the drain tank 54, the drain discharge path 56, and the drain valve 58 may be omitted, and the connection path 60 may be directly connected to the communication path 22c.

In the third and fourth embodiments, the control unit 59 opens and closes the open / close valve based on the pressure of the steam sucked into the steam chamber 32 and the pressure of the steam discharged from the steam chamber 32 when the drive source 3 is started. You may make it determine whether 62 is made into an open state. That is, in this modification, pressure sensors are provided at the suction port 33 and the discharge port 34, respectively, and a detection signal is input to the control unit 59 from each pressure sensor. When the start switch is turned on, the control unit 59 determines whether or not the pressure of the suction port 33 is lower than the atmospheric pressure based on the input detection signal, and the pressure of the discharge port 34 is high. It is determined whether the pressure is lower than the atmospheric pressure. When the control unit 59 determines that the pressure at the suction port 33 is lower than atmospheric pressure and the pressure at the discharge port 34 is lower than atmospheric pressure, the control unit 59 opens the on-off valve 62.

  In this configuration, only when the steam sucked into the steam chamber 32 immediately after the start of the steam compressor is lower than the atmospheric pressure and the vapor pressure at the discharge port 34 of the steam chamber 32 is lower than the atmospheric pressure, Steam having a pressure higher than atmospheric pressure is supplied from the discharge-side steam pipe 102 to the communication portion 22. When the steam compressor is started, the steam sucked into the steam chamber 32 is lower than the atmospheric pressure, and the steam pressure in the vicinity of the discharge port 34 of the steam chamber 32 (steam leaking from the steam chamber 32 to the discharge side shaft seal chamber 39). When the pressure is lower than the atmospheric pressure, it is preferable to supply steam at a pressure higher than the atmospheric pressure from the discharge side steam pipe 102 to the region between the seal portions 10 and 12 of the suction side shaft sealing chamber 35. Therefore, in this configuration, it is possible to supply steam to the region only in such a case. In other words, when it is not necessary to supply steam from the discharge-side steam pipe 102 to the region between the seal portions 10 and 12 of the suction-side shaft sealing chamber 35 when the steam compressor is started, steam is not supplied to the region. It is possible to prevent the steam in the discharge side steam pipe 102 from being wasted.

  The steam compressed by the steam compressor may be steam other than water vapor. In this case, the liquid contained in the vapor flowing out from the discharge side shaft sealing chamber 39 to the communication portion 22 may be a liquid other than water.

2 Rotor for compression 2a Compression portion 2b Rotor shaft 3 Drive source 4 Housing 10 First suction side seal portion (first seal portion)
12 Second suction side seal part (second seal part)
14 Third suction side seal (lip seal)
14b Lip part 16 1st discharge side seal part (3rd seal part)
22 Communication Portion 32 Steam Chamber 33 Suction Port 34 Discharge Port 35 Suction Side Shaft Seal Chamber 37 Suction Side Oil Chamber (Oil Chamber)
38 Suction-side open air path (open air path)
39 Discharge side shaft seal chamber 52 Pressure control valve 53 Excess steam discharge path 54 Drain tank 56 Drain discharge path 58 Control unit 60 Connection path 62 On-off valve 102 Discharge side steam pipe (steam pipe)

Claims (6)

A steam chamber provided with a steam suction port on one side in the longitudinal direction and a steam discharge port on the other side in the longitudinal direction; a suction side shaft sealing chamber communicating with the steam suction side of the steam chamber; A housing having a discharge-side shaft sealing chamber that communicates with the steam discharge side of the steam chamber, and an atmosphere opening path that communicates the suction-side shaft sealing chamber and the atmospheric space;
Steam having a compression section accommodated in the steam chamber and a rotor shaft extending through the shaft sealing chamber on both sides from the compression section, and the compression section being sucked into the steam chamber by rotating around the axis A rotor for compression that compresses while sending to the discharge port side,
A first seal that is disposed in a position spaced from the connection portion of the atmosphere opening path to the steam chamber side in the suction side shaft sealing chamber, and suppresses the flow of the steam in the steam chamber to the atmosphere opening path. And
A second seal portion disposed at a position between the connection portion of the atmosphere opening path and the first seal portion in the suction side shaft sealing chamber, and for suppressing the flow of steam to the atmosphere opening path; ,
A non-contact third seal portion disposed in the discharge-side shaft seal chamber, for increasing a flow resistance against steam leaking from the steam chamber to the discharge-side shaft seal chamber;
A region of the suction side shaft sealing chamber located between the first seal portion and the second seal portion, and a side opposite to the steam chamber with respect to the third seal portion of the discharge side shaft sealing chamber. a communicating portion for communicating the region located,
A pressure control valve connected to the communication part ,
The first seal portion has an inner screw portion through which the rotor shaft is inserted, and a gap is formed between the inner peripheral surface of the inner screw portion and the outer peripheral surface of the rotor shaft. Ri contactless seal portion der provided so that,
The pressure regulating valve has a predetermined setting in which the pressure of the steam flowing from the region located on the opposite side of the steam chamber to the third seal portion in the discharge side shaft seal chamber is higher than the atmospheric pressure. When the pressure is higher than the pressure, it is possible to maintain the pressure of the steam introduced from the communication portion into the region located between the first seal portion and the second seal portion in the suction side shaft seal chamber at the set pressure. Constructed in a steam compressor. The housing communicates with the suction side shaft sealing chamber, and is provided with an oil chamber in which lubricating oil is stored.
Lubricating oil that has flowed out of the oil chamber flows toward the steam chamber in the suction-side shaft seal chamber at a position closer to the oil chamber than the connection site of the atmosphere opening path in the suction-side shaft seal chamber. The steam compressor according to claim 1, further comprising a lip seal having a lip portion that comes into contact with the outer peripheral surface of the rotor shaft in a posture to prevent the above. The communication portion has a drain tank for separating liquid contained in the vapor flowing from the discharge side shaft sealing chamber to the suction side shaft sealing chamber,
3. The steam compressor according to claim 1, wherein the pressure control valve maintains the pressure of the steam from which the liquid is separated in the drain tank at the set pressure. The steam compressor according to claim 3 , wherein a drain discharge path for discharging liquid accumulated in the drain tank is connected to the drain tank, and the drain discharge path is connected to the suction port. An excess steam discharge path is connected to the pressure control valve, and the pressure control valve discharges excess steam to the excess steam discharge path when the pressure of the steam in the communication portion exceeds the set pressure. Composed of
The steam compressor according to any one of claims 1 to 4 , wherein the surplus steam discharge passage is connected to the suction port. A drive source for rotating the compression rotor;
A control unit for controlling the driving of the driving source,
The communication portion is connected to a steam pipe through which steam having a pressure higher than atmospheric pressure flows through a connection path provided with an on-off valve,
The steam compressor according to any one of claims 1 to 5 , wherein the control unit opens the on-off valve with the activation of the drive source.

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