Patent Publication Number: US-11028839-B2

Title: Compressing device and method for carrying out compressing device

Description:
TECHNICAL FIELD 
     The present invention relates to a compressing device configured to compress gas in a housing and a method for carrying out a cylinder portion of the compressing device. 
     BACKGROUND ART 
     Compressed gas may be supplied outdoors (e.g. a hydrogen station). In this case, a compressor configured to compress the gas is situated outdoors. For protecting the compressor situated outdoors against wind and weather, the compressor is placed in a housing. 
     For maintenance work of the compressor; the compressor may be disassembled in the housing. JP 2015-232384 A proposes taking out disassembled parts of the compressor through an opening portion formed on a roof of the housing. 
     With regard to JP 2015-232384 A, heavy equipment configured to lift up a cylinder as one part of a reciprocating compressor is required because the cylinder is carried to the outside through the opening portion formed on the roof of the housing. Since it is necessary to prepare heavy equipment, operate the heavy equipment, and further obtain an installation space for the heavy equipment, the conventional compressing device needs a lot of labor for the maintenance of the compressor in the housing. 
     SUMMARY OF INVENTION 
     An object of the present invention is to provide techniques for a reduction in labor for maintenance of a compressor. 
     A compressing device according to one aspect of the present invention includes a compressor having a cylinder portion configured to form a compression chamber in which gas is compressed: a housing having a peripheral wall configured to form an internal space in which the compressor is stored; and a supporting member situated above the compressor in the internal space. The peripheral wall includes an opening wall in which a carry-out port is formed so that the cylinder portion is carried out through the carry-out port. The supporting member extends to guide movement of a first lifting device between a position above the compressor and a position above the carry-out port, the cylinder portion being hung from the first lifting device. 
     A method according to another aspect of the present invention is used for carrying a cylinder portion of a compressor out of a carry-out port formed in a peripheral wall of a housing configured to an internal space in which the compressor is stored, the cylinder portion forming a compression chamber in which gas is compressed. The method includes lifting the cylinder portion by using a first lifting device supported by a supporting member which is situated above the compressor in the internal space; and moving the first lifting device from a position above the compressor toward a position above the carry-out port along the supporting member to carry the cylinder portion to the carry-out port, the cylinder portion being lifted up by the first lifting device. 
     An object, features and advantages of the aforementioned compressing device and method will become more apparent from detailed description and accompanying drawings set forth below. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic perspective view of a part of a compressing device according to the first embodiment; 
         FIG. 2  is a schematic front view of a part of the compressing device; 
         FIG. 3  is a schematic perspective view of the compressing device; 
         FIG. 4  is a schematic sectional view of the compressing device; 
         FIG. 5  is a schematic perspective view of a cylinder portion as a conveyance object which is carried toward a carry-out port of the compressing device; 
         FIG. 6  is a schematic perspective view of the cylinder portion carried near the carry-out port; and 
         FIG. 7  is a schematic perspective view of a part of a compressing device according to the second embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     First Embodiment 
       FIG. 1  is a schematic perspective view of a part of a compressing device  100  according to the first embodiment.  FIG. 2  is a schematic front view of a part of the compressing device  100 .  FIG. 3  is a schematic perspective view of the compressing device  100 . A schematic structure of the compressing device  100  is described with reference to  FIGS. 1 to 3 . 
     The compressing device  100  is used for generating compressed gas (i.e. hydrogen). The compressing device  100  includes a housing  110 , a compressor  120  situated in the housing  110 , a supporting structure  130  situated above the compressor  120  in the housing  110 , and a canopy  140  attached to an outer surface of the housing  110 . The housing  110  forms an internal space  111  (c.f.  FIG. 1 ) in which the compressor  120  and the supporting structure  130  are stored. Not only the compressor  120  and the supporting structure  130  but also various devices (e.g. a heat exchanger) required for generating compressed gas (not shown) are stored in the internal space  111 . The compressor  120  fixed in the internal space  111  compresses gas. When a maintenance work of the compressor  120  is conducted, the supporting structure  130  is used for lifting up a part of the compressor  120  in the housing  110 . The canopy  140  situated outside the housing  110  not only protects workers getting into and out of the internal space  11  against rain but is also used for carrying out a part of the compressor  120  to the outside of the housing  110  when the maintenance work of the compressor  120  is conducted. Structures of the housing  110 , the canopy  140 , the compressor  120  and the supporting structure  130  are described below. 
     The housing  110  is a rectangular box (c.f.  FIG. 3 ) having a peripheral wall  112  standing so as to surround the compressor  120 , and a roof  113  formed to close a rectangular opening portion surrounded by the upper edge of the peripheral wall  112 . Accordingly, the peripheral wall  112  of the housing  110  includes four wall portions forming four surfaces. A wide wall portion of the peripheral wall  112  shown in  FIG. 3  is referred to as “front wall  114 ” in the following description. A wall portion forming a surface extending backward from a left edge of the front wall  114  is referred to as “left wall  115 ”. According to the names of these wall portions, directional terms such as “front”, “rear”, “left” and “right” are used below. These directions are only for clarifying the description but not to be construed as limiting in any manner. 
     The left wall  115  of the housing  110  includes an opening wall  117 , in which a substantially rectangular carry-out port  116  (c.f.  FIG. 1 ) is formed so that a part of the compressor  120  is carried out from the carry-out port  116 , and a door  118  which opens and closes the carry-out port  116 . The door  118  shown in  FIGS. 1 and 2  opens the carry-out port  116 . The door  118  shown in  FIG. 3  closes the carry-out port  116 . The carry-out port  116  is used not only for carrying out the compressor  120  but also for allowing the workers to get into and out of the internal space  111 . 
     Above the carry-out port  116 , the canopy  140  is fixed to the outer surface of the opening wall  117 . 
     The workers may open the door  118  below the canopy  140  to enter the internal space  111 . There is a work space around the compressor  120 , the work space being wide enough for the workers to disassemble the compressor  120  in the internal space  111 . A structure of the compressor  120  is described below. 
       FIG. 4  is a schematic sectional view of the compressor  120 . The structure of the compressor  120  is schematically described with reference to  FIGS. 1 and 4 . 
     The compressor  120  includes a crank mechanism  121 , a first compression portion  122  situated above the crank mechanism  121 , and a second compression portion  123  situated above the crank mechanism  121  behind the first compression portion  122 . Gas is compressed in the first and second compression portions  122 ,  123  under an operation of the crank mechanism  121 . 
     The first compression portion  122  includes a piston configured to reciprocate vertically (not shown), and a cylinder portion  421  in which the piston is stored. The piston and the cylinder portion  421  form a compression chamber (not shown) in which the gas is compressed. 
     The cylinder portion  421  includes a substantially tubular member  423  forming a housing space in which the piston is stored, and a distal end portion  422  which closes the upper portion of the substantially tubular member  423 . A space surrounded by the distal end portion  422 , the substantially tubular member  423  and the piston is used as a compression chamber in which the gas is compressed. 
     The second compression portion  123  is situated behind the cylinder portion  421  formed by the substantially tubular member  423  and the distal end portion  422 . The second compression portion  123  includes a piston configured to reciprocate vertically (not shown), and a cylinder portion  321  in which the piston is stored. The cylinder portion  321  includes a substantially tubular member  323  forming a housing space in which the piston is stored, and a distal end portion  322  closing the upper portion of the substantially tubular member  323 . A space surrounded by the distal end portion  322 , the substantially tubular member  323  and the piston is used as a compression chamber in which the gas is compressed. 
     Bolt holes (not shown) are formed in the upper surfaces of the distal end portions  322 ,  422  of the first and second compression portions  122 ,  123 , respectively. Eyebolts EBTs are screwed into the bolt holes when the maintenance work of the compressor  120  is conducted. 
     The eyebolts EBTs attached to the distal end portions  322 ,  422  are connected to lifting wires LCN of two first lifting devices FCB shown above the compressor  120  in  FIG. 1  at the time of the maintenance work. These first lifting devices FCBs are used for lifting the cylinder portions  321 ,  421  in the internal space  111 . A chain block with a wheel is used as each of these first lifting devices FCBs. However, another device capable of lifting the cylinder portions  321 ,  421  may be used as the first lifting device FCB. When a chain block is used as the first lifting device FCB, the lifting wire LCN is a chain. However, the lifting wire LCN may be a wire which is strong enough for lifting the cylinder portions  321 ,  421 . 
     The two first lifting devices FCB which lift the cylinder portions  321 ,  421  are supported by the supporting structure  130 . The supporting structure  130  is described below with reference to  FIGS. 1 and 3 . 
     The supporting structure  130  includes two supporting members which support the two first lifting devices FCB, respectively. One of the two supporting members is situated in correspondence to the first compression portion  122 , and is referred to as “first supporting member  131 ” in the following description. The other supporting member is situated in correspondence to the second compression portion  123 , and is referred to as “second supporting member  132 ” in the following description. 
     Right ends of the first and second supporting members  131 ,  132  are connected to a reinforcing frame RFM extending backward from the front wall  114 , the reinforcing frame RFM being provided on the right of the left wall  115  to reinforce the housing  110 . Left ends of the first and second supporting members  131 ,  132  are connected to another reinforcing frame (not shown) situated above the carry-out port  116 , the other reinforcing frame extending substantially horizontally along the inner surface of the left wall  115 . Accordingly, the first and second supporting members  131 ,  132  extends rightward from the inner surface of the left wall  115 . The first supporting member  131  is substantially in parallel to the second supporting member  132 . 
     The first supporting member  131  is situated above the first compression portion  122 . The first supporting member  131  is not necessarily positioned immediately above the first compression portion  122 . The second supporting member  132  behind the first supporting member  131  is positioned above the second compression portion  123 . The second supporting member  132  is not necessarily positioned immediately above the second compression portion  123 . The second supporting member  132  is substantially the same in structure and shape as the first supporting member  131 . Accordingly, the following description about the structure and the shape of the first supporting member  131  is applicable to the second supporting member  132 . 
     The first supporting member  131  includes an intermediate plate portion  134 , which forms substantially vertical front and rear surfaces, a lower plate portion  135 , which protrudes forward and rearward from the lower edge of the intermediate plate portion  134 , and an upper plate portion  136 , which protrudes forward and rearward from the upper edge of the intermediate plate portion  134 . Since the first supporting member  131  has the H-shaped cross section, an H-shaped steel may be used as the first supporting member  131 . 
     The wheel of the chain block (not shown) used as the first lifting device FCB is inserted into a gap between the upper and lower plate portions  136 ,  135  of the first supporting member  131 , so that the chain block is supported by the first supporting member  131 . The wheel of the chain block rotates on the upper surface of the lower plate portion  135  so that the chain block moves leftward and rightward along the first supporting member  131 . 
     When the chain block moves from the position above the compressor  120  to the left end of the first supporting member  131  (or the second supporting member  132 ) (i.e. a position above the carry-out port  116 ) with lifting the cylinder portion  421  (or  321 ), the cylinder portion  421  (or  321 ) hung below the chain block is carried near the carry-out port  116 . A second lifting device SCB is attached to a lower part of the canopy  140  in order to carry the cylinder portion  421  (or  321 ), which has been carried near the carry-out port  116 , to the outside of the housing  110  through the carry-out port  116 . In short, the canopy  140  is formed so that the second lifting device SCB is attached, the canopy  140  being strong enough to support the cylinder portion  421  (or  321 ). 
     The second lifting device SCB is attached to the lower part of the canopy  140  whereas the first lifting devices FCB are supported by the first and second supporting member  131 ,  132  extending along the lower surface of the roof  113  (c.f,  FIG. 3 ) at a higher position of the canopy  140 . Accordingly, the arrangement position of the second lifting device SCB is lower than the arrangement position of the first lifting device FCB. 
     Like the first lifting device FCB, the second lifting device SCB may be a chain block. However, another device capable of lifting the cylinder portion  421  (or  321 ) may be used as the second lifting device SCB. When a chain block is used as the second lifting device SCB, the lifting wire LCN of the second lifting device SCB is a chain. However, the lifting wire LCN of the second lifting device SCB may be a wire which is strong enough for lifting the cylinder portion  421  (or  321 ). 
     The second and first lifting devices SCB, FCB, and the canopy  140  and the supporting structure  130  supporting the second and first lifting devices SCB, FCB, respectively, are used for the maintenance work of the compressor  120 . Exemplary maintenance work of the compressor  120  is described below. 
     When the maintenance work is started, the workers install the lifting devices. One of the two first lifting devices FCB is attached to the first supporting member  131  so that the first lifting device FCB is situated above the cylinder portion  421  of the first compression portion  122 . The other first lifting device FCB is attached to the second supporting member  132  so that the other first lifting device FCB is situated above the cylinder portion  321  of the second compression portion  123 . The second lifting device SCB is attached to the canopy  140 . 
     After the installation work of the lifting devices FCB, SCB, the workers disassemble the cylinder portion as a conveyance object (i.e. either of the cylinder portion  321  or  421 ) from a crank case of the crank mechanism  121 . Consequently, the cylinder portion to be carried out becomes separable from the crank case of the crank mechanism  121 . Thereafter, a conveyance work is conducted to carry out the cylinder portion as the conveyance object to the outside of the housing  110 . 
     The conveyance work is roughly divided into a work of carrying the cylinder portion as the conveyance object to the carry-out port  116  and a work of carrying the cylinder portion as the conveyance object to the outside of the housing  110  through the carry-out port  116 . These works are described below. 
       FIG. 5  is a schematic perspective view of a cylinder portion  521  as the conveyance object (i.e. either of the cylinder portion  321  or  421 ) to the carry-out port  116 . It is described below with reference to  FIGS. 1 and 5  how to carry the cylinder portion  521  as the conveyance object to the carry-out port  116 . 
     With regard to the work of carrying the cylinder portion  521  as the conveyance object to the carry-out port  116 , the workers attach the eyebolt EBT to a distal end portion of the cylinder portion  521  (i.e. either the distal end portion  322  or  422  shown in  FIG. 1 ) at first. The workers attach a hook at the lower end of the lifting wire LCN of the first lifting device FCB to the eyebolt EBT. The workers operate the first lifting device FCB to wind up the lifting wire LCN. Accordingly, the cylinder portion  521  moves upward and is separated from the crank case of the crank mechanism  121 . 
     After the lifting wire LCN is wound up, the workers move the first lifting device FCB along a supporting member  133  (i.e. either of the first or second supporting member  131 ,  132  shown in  FIG. 1 ). Accordingly, the cylinder portion  521  hung from the first lifting device FCB moves toward the carry-out port  116 . It is described below how to carry out the cylinder portion  521  from the housing  110  through the carry-out port  116 , the cylinder portion  521  having been carried near the carry-out port  116 . 
       FIG. 6  is a schematic perspective view of the cylinder portion  521  which has been carried near the carry-out port  116 . The conveyance work of the cylinder portion  521  is described with reference to  FIG. 6 . 
     When the workers move the first lifting device FCB near the left end of the supporting member  133 , the cylinder portion  521  is positioned near the inner surface of the left wall  115 . The workers then operates the first lifting device FCB to move the cylinder portion  521  down so that the upper end of the cylinder portion  521  is positioned below the upper edge of the carry-out port  116 . 
     When the cylinder portion  521  moves down to an appropriate height position, the workers attach an end portion of a traction wire TWR to the hook attached to the end portion of the lifting wire LCN of the second lifting device SCB. Meanwhile, the other end portion of the traction wire TWR is connected to the eyebolt EBT which is attached to the cylinder portion  521 . Since the traction wire TWR and the lifting wire LCN of the second lifting device SCB, to which the traction wire TWR is tied, obliquely extend to the lower right from the second lifting device SCB outside the housing  110  toward the cylinder portion  521  in the housing  110 , one of component forces of tension acting on the traction wire TWR and the lifting wire LCN of the second lifting device SCB is oriented leftward. Since the carry-out port  116  is formed on the left side of the cylinder portion  521 , when the workers loosen the lifting wire LCN of the first lifting device FCB whereas the workers wind up the lifting wire LCN of the second lifting device SCB, the cylinder portion  521  is lifted upward and leftward so that the cylinder portion  521  is carried out of the housing  110  through the carry-out port  116 . 
     The first and second lifting devices FCB, SCB are used for the aforementioned maintenance work. A device having a size that can be arranged in the housing  110  (e.g. a chain block) may be used as the first and second lifting devices FCB, SCB. Accordingly, the workers may manually attach the first and second lifting devices FCB, SCB to a predetermined work position to carry the cylinder portions  321 ,  421  separated from the compressor  120  to the outside of the housing  110 . The maintenance work is conducted with less labor than a case where a cylinder portion is drawn out by heavy equipment through an opening formed in a ceiling portion of a housing. 
     The canopy  140 , to which the second lifting device SCB is attached, protects the cylinder portion  521  carried out of the carry-out port  116  and the workers conducting the maintenance work against rain. 
     With regard to the aforementioned embodiment, the compressor  120  has the two cylinder portions  321 ,  421 . However, the aforementioned carry-out techniques are applicable also to a compressor having one cylinder portion and a compressor having more than two cylinder portions. 
     With regard to the aforementioned embodiment, the first and second supporting members  131 ,  132  in correspondence to the cylinder portions  321 ,  421  are situated in the housing  110 . However, it may depend on a structure of a compressor how many supporting members are arranged in the housing. Accordingly, when a compressor has one cylinder portion, one supporting member may be arranged in the housing. Further, one supporting member may be arranged for cylinder portions although it depends on a distance between the cylinder portion and the supporting member, and an interval between the cylinder portions. In this case, one lifting device FCB is used for lifting the cylinder portions in the housing  110 . 
     With regard to the aforementioned embodiment, the cylinder portions  321 ,  421  are carried to the outside of the housing  110  through the carry-out port  116  by the second lifting device SCB after being carried near the carry-out port  116  by the first lifting device FCB. However, the cylinder portions  321 ,  421  may be carried out by a hand cart or the like near the carry-out port  116 . In this case, the second lifting device SCB is not required. 
     A single compression chamber or compression chambers may be formed in the cylinder portion  521  described in the context of the aforementioned embodiment. When the single compression chamber is formed in the cylinder portion  521 , one piston is stored in the cylinder portion  521 . When the compression chambers are formed in the cylinder portion  521 , pistons are stored in the cylinder portion  521 . 
     The cylinder portion  521  described in the context of the aforementioned embodiment may be configured with divisional parts. For example, the substantially tubular member  323  or  423  of the cylinder portion  521  may be configured with tubular elements. 
     With regard to the aforementioned embodiment, the cylinder portion  521  is lifted up alone. However, together with the cylinder portion  521 , other members of the compressing device  100  (e.g. a gas cooler or a piston) may be lifted up. 
     With regard to the aforementioned embodiment, the central axes of the cylinder portions  321 ,  421  extend vertically. However, the aforementioned carry-out techniques may be used for a compressing device which has a cylinder portion of which central axis extends horizontally. In this case, the laterally detached cylinder portion is raised by the first lifting device FCB so that the central axis extends vertically. Then, after being raised up by the first lifting device FCB, the cylinder portion is horizontally moved toward the carry-out port  116 . Eventually, the cylinder portion is carried out of the housing  110  through the carry-out port  116  by the second lifting device SCB outside the housing  110 . 
     With regard to the aforementioned embodiment, the cylinder portions  321 ,  421  and the crank case of the crank mechanism  121  are disassembled after the installation of the first and second lifting devices FCB, SCB. However, the cylinder portions  321 ,  421  and the crank case of the crank mechanism  121  may be disassembled before or during the installation of the first and second lifting devices FCB, SCB. 
     With regard to the aforementioned embodiment, the first and second lifting devices FCB, SCB are installed to the supporting member  133  and the canopy  140  at the start of the maintenance work. However, the first and second lifting devices FCB, SCB may be always placed on the supporting member  133  and the canopy  140 , respectively. 
     With regard to the aforementioned embodiment, the H-shaped steel is used as the supporting member  133 . However, the supporting member  133  may have another shape (e.g. a member having an I-shaped or C-shaped cross section) which guides horizontal movement of the first lifting device FCB. If a device for use together with a dedicated rail member is used as the first lifting device FCB, the dedicated rail is used as the supporting member. 
     With regard to the aforementioned embodiment, the first lifting device FCB is attached to the supporting member  133  whereas the second lifting device SCB is attached to the canopy  140 . However, the first and second lifting devices FCB, SCB may be attached to a common beam member. For example, an H-shaped steel extending through the opening wall  117  above the carry-out port  116  may be used as a beam member. In this case, the first lifting device FCB is attached to the H-shaped steel in the internal space  111 , and the second lifting device SCB is attached to the H-shaped steel outside the housing  110 . The first and second lifting devices FCB, SCB attached to the common H-shaped steel are supported at substantially the same height. 
     Second Embodiment 
     Since the canopy  140  of the compressing device  100  according to the first embodiment protrudes outward from the opening wall  117  above the carry-out port  116 , the canopy is suitably used as an attachment part of the second lifting device SCB which pulls the cylinder portion  521  outward. However, another protrusion member instead of the canopy  140  may be used as an attachment part of the second lifting device SCB. An alternative protrusion member is described in the second embodiment. 
       FIG. 7  is a schematic perspective view of a part of a compressing device  100 A according to the second embodiment. The compressing device  100 A is described with reference to  FIGS. 1 and 7 . 
     The compressing device  100 A is different from the compressing device  100  of the first embodiment only in a structure for supporting the second lifting device SCB. The description of the first embodiment is applicable to the compressing device  100 A except for the supporting structure for the second lifting device SCB. 
     As the supporting structure for the second lifting device SCB, the compressing device  100 A has a housing  110 A and a supporting frame  150 . The housing  110 A has a left wall  115 A instead of the left wall  115  described in the context of the first embodiment, two opening regions  211  being formed above the carry-out port  116  in the left wall  115 A ( FIG. 7  shows one of the two opening regions  211 ). The supporting frame  150  attached to the left wall  115 A is used as a protrusion member which is substituted for the canopy  140  described in the context of the first embodiment. Like the canopy  140  of the first embodiment, the supporting frame  150  is attached to the left wall  115 A. The second lifting device SCB is attached to the supporting frame  150 . Structures of the left wall  115 A and the supporting frame  150  are described below. 
     Like the first embodiment, the left wall  115 A includes the door  118 . The description of the first embodiment is applicable to the door  118 . 
     In addition to the door  118 , the left wall  115 A includes an opening wall  117 A and two covers  119  attached to the upper portion of the opening wall  117 A ( FIG. 7  shows one of the two covers  119 ). The carry-out port  116  and the aforementioned two opening regions  211  are formed in the opening wall  117 A. The two covers  119  are formed to close the two opening regions  211 . The cover  119  shown in  FIG. 7  closes the front opening region  211  whereas the cover  119  for closing the rear opening region  211  is detached. Accordingly, the rear opening region  211  appears in  FIG. 7 . 
     The cover  119  for closing the rear opening region  211  is detached when the cylinder portion  321  of the second compression portion  123  is carried out through the carry-out port  116  as shown in  FIG. 7 . On the other hand, the cover  119  for closing the front opening region  211  is detached when the cylinder portion  421  of the first compression portion  122  is carried out through the carry-out port  116 . 
     When the cover  119  is detached, a strut  212  appears, the strut  212  extending vertically so as to divide the opening region  211  into two regions. The strut  212  is incorporated into the opening wall  117 A as a part of the left wall  115 A in order to enhance a strength of the left wall  115 A around the opening region  211 . 
     The supporting frame  150  is attached to the strut  212  using a bolt (not shown). The supporting frame  150  includes an upper frame member  151  extending substantially horizontally from the strut  212  and a lower frame member  152  extending obliquely downward from the lower surface of the upper frame member  151  toward the left surface of the strut  212 . The second lifting device SCB is attached to the left end of the lower surface of the upper frame member  151 . When the second lifting device SCB lifts up the cylinder portion  321 , loads of the cylinder portion  321  and the second lifting device SCB are applied to the left end of the upper frame member  151 . Accordingly, the upper frame member  151  is about to bend downward. The lower frame member  152  arranged below the upper frame member  151  suppresses downward bending of the upper frame member  151 . Accordingly, the supporting frame  150  has a structure capable of satisfactorily enduring a heavy load of the cylinder portion  321 . 
     The workers may conduct the same maintenance work as in the first embodiment by using the second lifting device SCB attached to the supporting frame  150  to carry out the cylinder portion  521  from the housing  110 A through the carry-out port  116 . After the maintenance work, the workers detach the supporting frame  150  from the strut  212 . Thereafter, the workers close the opening region  211  with the cover  119 . 
     Since the workers detach the supporting frame  150  protruding from the left wall  115 A at the end of the maintenance work, the supporting frame  150  does not interfere with other works conducted after the maintenance work. Since the supporting frame  150  is designed only for the maintenance work, the supporting frame  150  does not have to be as large as the canopy  140  which is used not only for the maintenance work but also protection of the workers against rain. Accordingly, the supporting frame  150  is formed at low costs. 
     With regard to the aforementioned embodiment, the supporting frame  150  is attached to the strut  212  which is exposed when the cover  119  is detached. However, the supporting frame  150  may be directly attached to an opening wall having a high strength. In this case, neither the opening region  211  nor the cover  119  which covers the opening region  211  is required. 
     The disclosed embodiments are for illustrative purpose only and not to be construed as limiting in any manner. The scope of the present invention is demonstrated not by the above description but by the scope of claims and is construed to include meaning equivalent to the scope of claims and all modifications within the scope. 
     The aforementioned embodiments mainly include a compressing device having the following configuration and a method for carrying out the compressing device. 
     A compressing device according to one aspect of the aforementioned embodiment includes a compressor having a cylinder portion configured to form a compression chamber in which gas is compressed; a housing having a peripheral wall configured to form an internal space in which the compressor is stored; and a supporting member situated above the compressor in the internal space. The peripheral wall includes an opening wall in which a carry-out port is formed so that the cylinder portion is carried out through the carry-out port. The supporting member extends to guide movement of a first lifting device between a position above the compressor and a position above the carry-out port, the cylinder portion being hung from the first lifting device. 
     According to the aforementioned configuration, a worker may move the first lifting device from a position above the compressor toward a position above the carry-out port with hanging the cylinder portion from the first lifting device under a guide of the supporting member. Accordingly, the worker may carry the cylinder portion of the compressor toward the carry-out port. Since no heavy equipment is required for carrying the cylinder portion to the carry-out port, there is a reduction in labor for the maintenance of the compressor. 
     With regard to the aforementioned configuration, the compressing device may further include a protrusion member which protrudes outward from the opening wall above the carry-out port, the protrusion member being configured to support a second lifting device having a lifting wire extending obliquely downward through the carry-out port so that the lifting wire is connected to the cylinder portion which has been carried to the carry-out port. 
     According to the aforementioned configuration, since the supporting member extends in the internal space of the housing, the cylinder portion stays in the internal space of the housing even when the worker moves the first lifting device along the supporting member. On the other hand, the second lifting device used together with the first lifting device is situated outside the housing since the second lifting device is attached to the protrusion member which protrudes outward from the opening wall above the carry-out port. The lifting wire of the second lifting device extends obliquely downward through the carry-out port and is connected to the cylinder portion since the second lifting device is supported by the protrusion member positioned above the carry-out port outside the housing whereas the cylinder portion stays in the internal space of the housing before the second lifting device lifts up the cylinder portion. When the worker uses the second lifting device to lift up the cylinder portion, one of component forces acting on the lifting wire of the second lifting device is oriented outward, so that the cylinder portion is easily carried to the outside of the housing through the carry-out port. 
     With regard to the aforementioned configuration, the protrusion member is a canopy provided for the carry-out port. 
     According to the aforementioned configuration, since the protrusion member is a canopy provided for the carry-out port, the compressing device may protect the cylinder portion against rain when the cylinder portion is carried out of the housing through the carry-out port. 
     With regard to the aforementioned configuration, the protrusion member is detachable from the opening wall. 
     According to the aforementioned configuration, since the protrusion member is detachable from the opening wall, the worker may detach the protrusion member from the opening wall after the cylinder portion is carried out of the housing. Accordingly, there is no risk of the protrusion member interfering with other works for the compressing device after a maintenance work of the compressor. 
     A method according to the aforementioned embodiment is used for carrying a cylinder portion of a compressor out of a carry-out port formed in a peripheral wall of a housing configured to form an internal space in which the compressor is stored, the cylinder portion forming a compression chamber in which gas is compressed. The method includes lifting the cylinder portion by using a first lifting device supported by a supporting member which is situated above the compressor in the internal space; and moving the first lifting device from a position above the compressor toward a position above the carry-out port along the supporting member to carry the cylinder portion to the carry-out port, the cylinder portion being lifted up by the first lifting device. 
     According to the aforementioned configuration, the first lifting device situated in the internal space of the housing may move from a position above the compressor toward a position above the carry-out port along the supporting member. Therefore, it is possible to carry the cylinder portion to the carry-out port with the cylinder portion being lifted up by the first lifting device, Since no heavy equipment is required for carrying the cylinder portion to the carry-out port, there is a reduction in labor for the maintenance of the compressor. 
     With regard to the aforementioned configuration, the method further includes connecting a lifting wire to the cylinder portion which has been carried to the carry-out port, the lifting wire extending obliquely downward into the internal space through the carry-out port from a second lifting device which is situated outside the housing; and winding up the lifting wire of the second lifting device to lift up the cylinder portion connected to the lifting wire to carry the cylinder portion out of the carry-out port. 
     According to the aforementioned configuration, the worker may move the first lifting device along the supporting member to carry the cylinder portion up to a position in front of the carry-out port. The worker may extend the lifting wire obliquely downward from the second lifting device situated outside the housing to connect the lifting wire to the cylinder portion in front of the carry-out port. When the worker winds up the lifting wire of the second lifting device, one of component forces of tension acting on the lifting wire is oriented outward, so that the cylinder portion is easily carried to the outside of the housing through the carry-out port. 
     The aforementioned techniques enable to reduce labor for maintenance of a compressor. 
     The principle of the aforementioned embodiments is suitably used in various technical fields requiring compression of gas. 
     This application is based on Japanese Patent application No. 2018-097114 filed in Japan Patent Office on May 21, 2018, the contents of which are hereby incorporated by reference. 
     Although the present invention has been fully described by way of example with reference to the accompanying drawings, it is to be understood that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention hereinafter defined, they should be construed as being included therein.