JP4181817B2 - Two-stage screw compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a two-stage screw compressor having two compressor bodies and a cooler provided between the two compressor bodies.
[0002]
[Prior art]
Generally, a two-stage screw compressor has a low-pressure stage compressor body, a cooler that cools compressed air compressed by the low-pressure stage compressor body, and further compresses the compressed air cooled by the cooler. A high-pressure stage compressor body, and the compressed air that has been compressed by the low-pressure stage compressor body and heated to a high temperature is cooled by a cooler, thereby increasing the compression efficiency of the high-pressure stage compressor body. ing.
[0003]
At this time, in the cooler, depending on the temperature or humidity conditions of the intake air, moisture in the compressed air is condensed and droplets are generated. In particular, when the cooler is a water-cooled type, groundwater having a relatively low water temperature may be used as the cooling water, and in this case, the generation of droplets becomes significant. Therefore, usually, the two-stage screw compressor is provided with a primary droplet separation means between the cooler and the high-pressure stage compressor body, and the droplets generated in the cooler by the primary droplet separation means. By separating, droplets are prevented from being brought into the subsequent high-pressure stage compressor body.
[0004]
However, the droplet separation efficiency by the droplet primary separation means is limited, and as a result, droplets that cannot be separated by the droplet primary separation means flow into the high-pressure stage compressor body. The droplets flowing into the high-pressure stage compressor body in this way promote rusting of the casing of the high-pressure stage compressor body, particularly the suction port, and this rust bites the screw rotor of the high-pressure stage compressor body. This could cause a screw rotor stiffness.
[0005]
From such a background, for example, as described in JP-A-9-158870, it is provided between the low-pressure stage compressor body (one-stage compressor body) and the high-pressure stage compressor body (two-stage compressor body). A water-cooled cooler (intercooler) and a primary droplet separating means (drain separator) for separating droplets generated in the cooler, and a cooling water inlet pipe connected to the cooler and cooling water A two-stage screw compressor provided with a bypass pipe that bypasses the outlet pipe, a temperature control valve that detects the cooling water inlet temperature and adjusts the amount of cooling water flowing into the cooler according to the detected temperature. Has been advocated. According to this prior art, when the cooling water temperature is low, the cooling water flowing into the cooler is bypassed by a certain amount to reduce the cooling water amount to the cooler, and the temperature of the compressed air at the outlet of the cooler is reduced. By making it relatively high, the amount of droplets generated can be reduced. As a result, even if the separation efficiency of the droplet primary separation means is limited, the droplets can be prevented from flowing into the high-pressure stage compressor body.
[0006]
[Problems to be solved by the invention]
However, there are the following problems in the above-described prior art.
That is, in general, in a two-stage screw compressor, the compression efficiency of the high-pressure stage compressor body is reduced by cooling the compressed air that has been compressed by the low-pressure stage compressor body and heated to a high temperature as described above. To increase. Therefore, the range of increase in the compressed air temperature at the outlet of the cooler in the prior art is limited to a range that does not affect the performance of the compressor. Therefore, the amount of droplets generated cannot be reduced sufficiently depending on the temperature or humidity of the intake air. there is a possibility. For example, in a two-stage screw compressor capable of variably controlling the rotational speed of the motor using an inverter or the like, if the rotational speed of the motor decreases and the intake air amount becomes small, the cooling to the cooler Even if the amount of water is reduced, it becomes supercooled, and this may also not sufficiently reduce the amount of droplets generated.
[0007]
As described above, in the above-described prior art, there is a possibility that the amount of droplets generated cannot be reduced sufficiently depending on the state of the intake air or the operating conditions of the compressor, and the mixing of droplets into the high-pressure stage compressor body is suppressed. From this point of view, there is room for further improvement.
[0008]
An object of the present invention is to provide a two-stage screw compressor that can sufficiently suppress mixing of droplets into a high-pressure stage compressor body.
[0009]
[Means for Solving the Problems]
(1) In order to achieve the above object, a two-stage screw compressor of the present invention includes a low-pressure stage compressor body, a cooler that cools compressed air compressed by the low-pressure stage compressor body, Drops generated in the compressed air by cooling the cooler , By colliding with a wall surface substantially perpendicular to the flow direction of the compressed air flowing in a substantially horizontal direction, Primary droplet separating means for primary separation, and primary droplet separating means And the droplet primary separation means provided above The droplets that could not be separated by Consists of a closed tube with a closed plate at the upper end of the cylindrical part that is secondarily separated by collision. Droplet secondary separation means; A lead-out pipe for deriving compressed air from which the droplets have been separated by the closing tube from the outside of the tube portion of the closing tube below the closing plate, and the substantially vertical wall surface of the droplet primary separation means A discharge port which is positioned below and discharges the droplets separated by the droplet primary separation means and the droplet secondary separation means; and the outlet tube And a high-pressure stage compressor main body for further compressing the compressed air.
[0010]
In the present invention, droplets generated when the compressed air compressed by the low-pressure stage compressor body and heated to a high temperature is cooled by a cooler is first primarily separated from the compressed air by the droplet primary separation means, Those that could not be separated here are further separated by the secondary droplet separation means. Thereby, a droplet can fully be isolate | separated from compressed air and mixing of the droplet to the high-pressure stage side compressor main body can fully be suppressed. Accordingly, it is possible to prevent solid astringency due to rust of the high-pressure stage compressor body, and it is possible to improve the reliability of the two-stage screw compressor.
[0012]
As a result, the fine droplets generated in the cooler collide with the collision portion together with the compressed air by the flow of the compressed air, so that aggregation is promoted and become larger droplets. As a result, the liquid drops easily due to its own weight and can be easily separated from the compressed air, so that the droplets can be separated efficiently.
[0013]
Also, for example, when the conventional structure is modified to realize the configuration of the present invention, the existing droplets can be obtained simply by modifying the piping from the droplet primary separation means to the high-pressure stage compressor body and providing a collision part. It is possible to promote the separation of droplets while leaving the primary separation means. Therefore, the modification from the conventional structure can be easily and inexpensively performed.
[0016]
(2) Above (1) Preferably, the primary droplet separating unit and the secondary droplet separating unit are integrally configured.
[0017]
In general, a water-cooled cooler is integrally provided with a droplet primary separation means at its outlet, whereas an air-cooled cooler is not provided with a droplet primary separation means. For this reason, normally, in an air-cooled two-stage screw compressor, for example, a commercially available droplet primary separation means is provided outside the main body and connected to the cooler and the high-pressure stage compressor main body. The generated droplets are separated.
[0018]
According to the present invention, when the air-cooled two-stage screw compressor having the above-described conventional structure is modified to realize the configuration of the present invention, the droplet primary separation means provided outside the main body is integrally configured. It is only necessary to replace the droplet primary separation means and the droplet secondary separation means, and the conventional structure can be easily and inexpensively modified.
[0019]
(3) In the above (1) or (2), the droplet primary separation means is a cooler header provided integrally with the cooler, Outlet tube Is provided penetrating so as to protrude from the outside of the side of the closing tube to the inside.
(4) In said (3), the said discharge port is provided in the bottom part of the exit chamber through which the compressed air from the said cooler flows in the said cooler header.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a two-stage screw compressor according to the present invention will be described below with reference to the drawings.
First, a first embodiment of a two-stage screw compressor according to the present invention will be described below with reference to FIGS.
[0021]
FIG. 1 is a schematic diagram showing the overall structure of the first embodiment of the two-stage screw compressor of the present invention. The white arrows in FIG. 1 indicate the flow of compressed air, the thick black arrows indicate the flow of oil, the black thin arrows indicate the flow of cooling water, and the gray arrows indicate the flow of cooling air. .
In FIG. 1, the first embodiment of the two-stage screw compressor of the present invention is a water-cooled two-stage screw compressor, which includes a low-pressure stage compressor body 1, And a high-pressure stage compressor body 2. Each of the low pressure stage side compressor body 1 and the high pressure stage side compressor body 2 includes drive screw rotors 1a and 2a and driven screw rotors 1b and 2b. These drive screw rotors 1 a and 2 a are respectively connected to pinion gears 5 and 6 via driven shafts 3 and 4, and these pinion gears 5 and 6 are bull gears 9 attached to the tip of the drive shaft 8 of the motor 7. Is engaged. As a result, when the drive shaft 8 of the motor 7 rotates, the drive force is transmitted to the drive screw rotors 1a and 2a via the bull gear 9, the pinion gears 5 and 6, and the driven shafts 3 and 4, whereby the drive screw rotor 1a, The driven screw rotors 1b, 2b rotate in conjunction with 2a, and the low-pressure stage compressor body 1 and the high-pressure stage compressor body 2 compress air.
[0022]
The pinion gears 5 and 6 and the bull gear 9 are housed in a gear case 10. The oil in the gear case 10 is circulated by the oil pump 11 (see the black thick arrow in FIG. 1), and the low pressure stage side compressor body 1 and the high pressure stage side compressor are passed through the oil cooler 12 and the oil filter 13. After being supplied to the main body 2, it returns to the gear case 10 again.
[0023]
When the low-pressure stage compressor body 1 rotates, the compression air is sucked into the low-pressure stage compressor body 1 from the outside via the filter 14 and compressed. The compressed air that has been compressed by the low-pressure stage compressor main body 1 to a high temperature is introduced into the inlet chamber 16 </ b> A of the intercooler header 16 through the introduction pipe 15 and cooled by the intercooler 17. The compressed air cooled by the intercooler 17 is sucked into the high-pressure stage compressor body 2 from the outlet chamber 16B of the intercooler header 16 through the closing pipe 18 and the outlet pipe 19 and further compressed. The compressed air further compressed by the high-pressure stage compressor body 2 is introduced into the aftercooler 22 through the discharge pipe 20 and the check valve 21, cooled by the aftercooler 22, and then discharged to the outside. It is like that.
[0024]
The oil cooler 12, the intercooler 17, and the after cooler 22 are supplied with cooling water (see the black thin line arrows in FIG. 1), and the cooling water cools oil or compressed air. ing. Further, by introducing cooling air into the compressor unit by the ventilation fan 23, the inside of the compressor unit can be ventilated (see gray arrows in FIG. 1).
[0025]
As described above, the interior of the intercooler header 16 is separated into the inlet chamber 16A and the outlet chamber 16B. FIG. 2 is a longitudinal sectional view showing the detailed structure of the intercooler header 16.
In FIG. 2, the intercooler header 16 is internally separated into an inlet chamber 16A and an outlet chamber 16B located above the inlet chamber 16A by a partition wall 24, and the inlet chamber 16A and the outlet chamber 16B are connected to each other. The cooler 17 side is open. In addition, the intercooler header 16 includes a flange portion 16a on the outer peripheral side at the end on the intercooler 17 side.
[0026]
A flange 25 is fixed to the end portion of the intercooler 17 on the side of the intercooler header 16 by, for example, welding. The flange 25 and the intercooler header collar portion 16a are bolted at a plurality of positions with the connection plate 26 interposed therebetween. The intercooler header 16 and the intercooler 17 are fixed by being fastened and fixed by the nut 27 and the nut 28.
[0027]
The intercooler 17 includes a plurality of substantially U-shaped air pipes 29 therein, and both ends of the air pipes 29 penetrate the connection plate 26 and the inlet chamber 16A of the intercooler header 16. The outlet chamber 16B is divided and communicated with each other. Thereby, the compressed air introduced from the introduction pipe 15 flows into the air pipe 29 from the inlet chamber 16A, is cooled in the intercooler 17 while flowing through the air pipe 29, and is led out to the outlet chamber 16B. It has become.
[0028]
The outlet chamber 16B has a substantially upper half area inside the intercooler header 16 and an upper and lower area opposite to the intercooler 17 (right side in FIG. 2). Thereby, the compressed air led out from the air pipe 29 of the intercooler 17 flows in the outlet chamber 16B to the opposite side to the intercooler 17, and collides with the inner surface of the side wall 16b in a substantially horizontal direction. . Further, a droplet (drain) receiving portion 16B is provided at the lower portion of the outlet chamber 16B on the side wall 16b side region. ₁ Is formed, and this droplet receiving portion 16B ₁ A droplet discharge port 16d is formed in the bottom portion 16c. Thus, the droplet receiving portion 16B is passed from the droplet discharge port 16d via the drain pipe 30, the check valve 31, the filter 32, and the orifice 33. ₁ The liquid droplets received in step 1 can be discharged at any time (details will be described later).
[0029]
The upper portion of the outlet chamber 16B (more specifically, the droplet receiving portion 16B ₁ Is formed with a discharge port 16e, and an edge portion 16f is provided around the discharge port 16e. Further, a flange 34 is fixed to the lower end portion of the closing tube 18 by, for example, welding, and the closing tube 18 is fixed to the intercooler by fixing the flange 34 and the edge portion 16f with a plurality of bolts 35. It stands on the top of the header 16.
[0030]
FIG. 3 is a longitudinal sectional view showing the structure of the closing tube 18.
In FIG. 3, the closing tube 18 includes a cylindrical portion 18a and an upper opening 18a of the cylindrical portion 18a. ₁ And the flange 34 fixed to the cylindrical portion 18a by welding as described above is bolted to the intercooler header edge 16f so as to be fixed to the intercooler header 16. It has become. At this time, the lower opening 18a of the cylindrical portion 18a ₂ Is in communication with the intercooler header discharge port 16e.
[0031]
The cylindrical portion 18a has a through hole 18a. ₃ Are formed in the through hole 18a. ₃ The lead-out pipe 19 is inserted into the cylindrical portion 18a from the outside to the inside, and is fixed by, for example, welding. The outlet tube 19 includes a short tube portion 19a inserted into the cylindrical portion 18a, an elbow portion 19b connected to the short tube portion 19a, and a short tube portion 19c connected to the elbow portion 19b (see FIG. 2). ) And an elbow portion 19d having one end connected to the short pipe portion 19c and the other end connected to the high-pressure stage compressor body 2 via a flange 36. The short pipe portion 19a, the elbow portion 19b, the short pipe portion 19c, and the elbow portion 19d are connected to each other by, for example, butt welding.
[0032]
In the above, the intercooler 17 constitutes a cooler that cools the compressed air that is compressed by the low-pressure stage compressor body described in the claims, and the outlet chamber 16B is formed in the compressed air by cooling the cooler. Constitutes a primary droplet separation unit that primarily separates the droplets generated in the liquid droplets, and the closed tube 18 constitutes a secondary droplet separation unit that further separates droplets that could not be separated by the primary droplet separation unit. To do. The intercooler header 16 constitutes a cooler header, the intercooler header side wall 16b constitutes a wall surface substantially perpendicular to the flow direction of the compressed air, and the closing plate portion 18b constitutes a collision portion where the compressed air collides. To do.
[0033]
Next, the operation and action of the first embodiment of the two-stage screw compressor of the present invention having the above configuration will be described below.
Compressed air that has been compressed by the low-pressure stage compressor body 1 to a high temperature is introduced into the inlet chamber 16A of the intercooler header 16 through the inlet pipe 15, and flows into the air pipe 29 from the inlet chamber 16A. 17 is cooled.
[0034]
Here, the cooling capacity of the intercooler 17 is set so that the air temperature at the outlet of the intercooler 17 becomes the cooling water temperature + about 20 ° C., the air temperature is 30 ° C., the humidity is 80%, and the cooling water temperature is the above air. It is designed so that the droplets are not theoretically contained in the air flowing out from the intercooler 17 under the conditions that are substantially equal to the temperature. However, when the intake air temperature or humidity is relatively high, or when the cooling water temperature is relatively low, moisture in the compressed air is condensed and droplets are generated.
[0035]
In this way, when droplets are generated by being cooled by the intercooler 17, the compressed air led out from the air pipe 29 to the outlet chamber 16B is generated inside the intercooler header side wall 16b together with the generated minute droplets. Collides with the surface in a substantially horizontal direction. As a result, the minute droplets are promoted to agglomerate on the inner surface of the side wall 16b, become larger droplets, and the droplet receiving portion 16B is caused by its own weight. ₁ Fall into. In this way, compressed air and droplets are primarily separated in the outlet chamber 16B.
[0036]
However, at this time, the droplet separation efficiency in the outlet chamber 16B is about 80 to 90%, and the remaining about 10 to 20% of the droplets that could not be separated flows into the closed tube 18 at the rear stage together with the compressed air. To do.
[0037]
The compressed air that has flowed into the blocking tube 18 rises in the cylindrical portion 18a and collides with the inner surface of the blocking plate 18b together with liquid droplets that cannot be separated in the outlet chamber 16B. As a result, as in the case of the collision of the side wall 16b, the minute droplets are promoted to agglomerate on the inner surface of the closing plate 18b, become larger droplets, and the droplet receiving portion 16B below the self-weight. ₁ Fall towards In this way, compressed air and droplets are secondarily separated in the closed tube 18.
[0038]
At this time, the droplets separated from the compressed air in the outlet chamber 16B and the closed tube 18 are dropped into the droplet receiving portion 16B. ₁ From the droplet discharge port 16 d, the drain pipe 30, the check valve 31, the filter 32, and the orifice 33.
[0039]
The compressed air from which the droplets are secondarily separated in the closed tube 18 flows into the outlet tube short tube portion 19a, and enters the high pressure stage compressor body 2 via the elbow portion 19b, the short tube portion 19c, and the elbow portion 19d. be introduced. The compressed air further compressed by the high-pressure stage compressor body 2 is introduced into the aftercooler 22 through the discharge pipe 20 and the check valve 21, cooled by the aftercooler 22, and then discharged to the outside. .
[0040]
As described above, in the first embodiment of the two-stage screw compressor of the present invention, liquid droplets generated when the intercooler 17 cools the compressed air from the low-pressure stage compressor body 1. Are first separated from the compressed air in the outlet chamber 16B, and the droplets that could not be separated in the outlet chamber 16B are further subjected to secondary separation in the closed tube 18 at the subsequent stage. Thereby, the droplet which generate | occur | produces in the intercooler 17 can fully be isolate | separated from compressed air, and mixing of the droplet to the high pressure stage side compressor main body 2 can fully be suppressed. Therefore, it is possible to prevent the agitation of the screw rotors 2a and 2b due to rusting of the casing of the high-pressure stage compressor body 2, particularly the suction port portion, and to improve the reliability of the two-stage screw compressor. Can do.
[0041]
Further, according to the present embodiment, the droplets separated by the closing tube 18 are dropped into the droplet receiving portion 16B of the lower outlet chamber 16B. ₁ Therefore, the liquid droplet discharge port 16d provided in the outlet chamber 16B, the drain pipe 30, the check valve 31, and the filter 32 are not provided without newly providing a liquid droplet discharge facility for the blocking pipe 18. , And the droplet discharge facility comprising the orifice 33 can be shared.
[0042]
For example, when remodeling a conventional two-stage screw compressor to achieve the configuration of the present embodiment, the corner of the pipe from the conventional intercooler header to the high-pressure stage compressor body is modified. Then, only by forming the closed tube 18, it is possible to perform the secondary separation of the droplets while leaving the existing intercooler header. Therefore, the modification from the conventional structure can be easily and inexpensively performed. Further, in this case, by providing the closing tube 18 above the existing intercooler header, the existing intercooler header droplet discharge facility can be diverted.
[0043]
In addition, according to the present embodiment, since no filter is used at all, it is possible to prevent an increase in pressure or an increase in pressure loss due to filter clogging that occurs when a droplet separator having a general structure with a built-in filter is used. Can be prevented.
[0044]
In the first embodiment of the present invention, the through hole 18a in which the blocking tube 18 and the outlet tube 19 are provided in the cylindrical portion 18a. ₃ However, the present invention is not limited to this, and the tee portion 37 is used to form the closed tube 18 ′ as shown in FIG. 4, and the tee portion 37 connects to the derivation tube 19. You may make it do.
[0045]
Next, a second embodiment of the two-stage screw compressor of the present invention will be described below with reference to FIGS. In this embodiment, the present invention is applied to an air-cooled two-stage screw compressor.
[0046]
FIG. 5 is a schematic diagram showing the overall structure of the second embodiment of the two-stage screw compressor of the present invention. The white arrows in FIG. 5 indicate the flow of compressed air, and the gray arrows indicate the flow of cooling air.
In FIG. 5, the second embodiment of the two-stage screw compressor of the present invention is an air-cooled two-stage screw compressor, which includes a low-pressure stage side compressor body 39, And a high-pressure stage compressor main body 40. Each of the low-pressure stage side compressor body 39 and the high-pressure stage side compressor body 40 includes driving screw rotors 39a and 40a and driven screw rotors 39b and 40b, and the driving force of the motor 41 is a pulley 42 and a bull gear 43. By being transmitted to the drive screw rotors 39a and 40a via the pinion gears 44 and 45, the low-pressure stage side compressor body 39 and the high-pressure stage side compressor body 40 respectively compress air.
[0047]
The compressed air compressed by the low-pressure stage compressor body 39 is introduced into the intercooler 47 through the introduction pipe 46 and cooled. The compressed air cooled by the intercooler 47 is introduced into the droplet separator 49 through the introduction pipe 48, and the compressed air from which the droplets have been separated by the droplet separator 49 is pressurized through the outlet pipe 50. It is sucked into the stage side compressor body 40 and further compressed. The compressed air further compressed by the high-pressure stage compressor body 40 is cooled by the aftercooler 51 and then discharged to the outside.
[0048]
The intercooler 47 and the aftercooler 51 are air-cooled by cooling air sucked into the compressor unit by the ventilation fan 52 (see gray arrows in FIG. 5).
[0049]
FIG. 6 is a longitudinal sectional view showing the structure of the droplet separator 49.
In FIG. 6, the droplet separator 49 includes a short tube 53, a primary separation chamber 54, a closing tube 55 as a secondary separation chamber, and a short tube 56.
[0050]
The short pipe 53 is connected to the introduction pipe 48 via the flange 57, and introduces the cooled compressed air from the intercooler 47 into the primary separation chamber 54.
[0051]
In the primary separation chamber 54, a collision plate 58 is provided substantially perpendicular to the flow direction of the compressed air introduced from the short tube 53, and a droplet discharge port 54b is provided at the bottom 54a of the primary separation chamber 54. It has been drilled. The droplets separated in the primary separation chamber 54 can be always discharged from the droplet discharge port 54b via the drain pipe 59 and the check valve 60 (see FIG. 5).
[0052]
The closing tube 55 includes a cylindrical portion 55a and a closing plate portion 55b fixed to the upper end portion of the cylindrical portion 55a. The lower end portion of the cylindrical portion 55a is penetrated so as to be inserted into the primary separation chamber 54, For example, it is fixed by welding.
[0053]
The short pipe 56 is inserted into the cylinder portion 55a from the lateral outside to the inside, and is fixed by, for example, welding. The end of the short pipe 56 opposite to the closing pipe 55 is connected to the outlet pipe 50 via a flange 61 so that the compressed air that is secondarily separated from the droplets by the closing pipe 55 is led to the outlet pipe 50. It has become.
[0054]
In the above, the intercooler 47 constitutes a cooler that cools the compressed air compressed by the low-pressure stage compressor body described in the claims, and the primary separation chamber 54 is compressed air by cooling the cooler. The liquid droplet primary separation means that primarily separates the liquid droplets generated therein is configured, and the closing tube 55 is a liquid droplet secondary separation means for further separating the liquid droplets that could not be separated by the liquid droplet primary separation means. Constitute. Further, the collision plate 58 constitutes a wall surface substantially perpendicular to the flow direction of the compressed air, and the blocking plate portion 55b constitutes a collision portion where the compressed air collides.
[0055]
Next, the operation and action of the second embodiment of the two-stage screw compressor of the present invention having the above configuration will be described below.
The compressed air compressed by the low-pressure stage compressor body 39 is introduced into the intercooler 47 through the introduction pipe 46 and cooled. At this time, as described above in the first embodiment, depending on the temperature and humidity conditions of the intake air, moisture in the compressed air is condensed and droplets are generated.
[0056]
When droplets are generated by cooling in the intercooler 17, the compressed air is introduced into the droplet separator 49 from the introduction tube 48 together with the droplets. The compressed air introduced from the introduction pipe 48 into the primary separation chamber 54 via the short pipe 53 collides with the collision plate 58 in the substantially horizontal direction together with the minute droplets generated in the intercooler 17. Thereby, the minute droplets are promoted to agglomerate on the surface of the collision plate 58, become larger droplets, and fall to the bottom 54 a of the primary separation chamber 54 by their own weight. In this way, compressed air and droplets are primarily separated in the primary separation chamber 54.
[0057]
Thereafter, the compressed air flows into the closed tube 55 together with the droplets that could not be separated in the primary separation chamber 54. The compressed air that has flowed into the blocking tube 55 rises in the cylindrical portion 55a and collides with the inner surface of the blocking plate 55b. Thereby, the minute droplets are promoted to agglomerate on the inner surface of the closing plate 55b, become larger droplets, and fall to the bottom 54a of the lower primary separation chamber 54 by their own weight. In this way, compressed air and droplets are secondarily separated in the closed tube 55.
[0058]
At this time, the droplets separated from the compressed air in the primary separation chamber 54 and the closed tube 55 are always discharged from the bottom 54 a of the primary separation chamber 54 through the droplet discharge port 54 b and the drain pipe 59.
[0059]
The compressed air from which the droplets have been separated by the droplet separator 49 as described above is further compressed by the high-pressure stage compressor body 40, cooled by the aftercooler 51, and then discharged to the outside.
[0060]
As described above, according to the second embodiment of the two-stage screw compressor of the present invention, droplets generated by the intercooler 47 are compressed air as in the first embodiment. Can be sufficiently separated from each other, and mixing of droplets into the high-pressure stage compressor body 40 can be sufficiently suppressed.
[0061]
Here, in general, in a water-cooled two-stage screw compressor, the intercooler is integrally provided with a droplet separator such as the intercooler header outlet chamber 16B in the first embodiment described above. On the other hand, in an air-cooled two-stage screw compressor, the intercooler does not include a droplet separator. For this reason, in an air-cooled two-stage screw compressor having a conventional structure, a commercially available droplet separator is usually provided outside the main body and connected to the intercooler and the high-pressure stage compressor main body. The droplets generated in the cooler are separated.
[0062]
According to the present embodiment, when the air-cooled two-stage screw compressor having the conventional structure is modified to realize the configuration of the present embodiment, a commercially available droplet separation provided outside the main body is provided. Since it is only necessary to replace the vessel with the droplet separator 49, modification from the conventional structure can be performed easily and inexpensively.
[0063]
【The invention's effect】
According to the present invention, by providing the droplet secondary separation means between the droplet primary separation means and the high pressure stage side compressor body, the compressed air compressed by the low pressure stage side compressor body is cooled by the cooler. The droplets generated at the time of the separation are first separated from the compressed air by the droplet primary separation means, and those that could not be separated here are further separated by the droplet secondary separation means. Thereby, a droplet can fully be isolate | separated from compressed air and mixing of the droplet to the high-pressure stage side compressor main body can fully be suppressed. Accordingly, it is possible to prevent solid astringency due to rust of the high-pressure stage compressor body, and it is possible to improve the reliability of the two-stage screw compressor.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing the overall structure of a first embodiment of a two-stage screw compressor according to the present invention.
FIG. 2 is a longitudinal sectional view showing a detailed structure of an intercooler header constituting the first embodiment of the two-stage screw compressor of the present invention.
FIG. 3 is a longitudinal sectional view showing the structure of a closed tube constituting the first embodiment of the two-stage screw compressor of the present invention.
FIG. 4 is a longitudinal sectional view showing the structure of a modified example of the closed tube constituting the first embodiment of the two-stage screw compressor of the present invention.
FIG. 5 is a schematic diagram showing the overall structure of a second embodiment of the two-stage screw compressor of the present invention.
FIG. 6 is a longitudinal sectional view showing the structure of a droplet separator constituting a second embodiment of the two-stage screw compressor of the present invention.
[Explanation of symbols]
1 Low pressure stage compressor body
2 High-pressure stage compressor body
16 Intercooler header (cooler header)
16B outlet chamber (primary droplet separation means)
16b Side wall (wall surface)
17 Intercooler (cooler)
18 Closure tube (Droplet secondary separation means)
18 'Occlusion tube (secondary droplet separation means)
18b Blocking plate part (collision part; blocking plate)
19 Lead pipe
39 Low pressure stage compressor body
40 High-pressure stage compressor body
47 Intercooler (cooler)
50 Lead pipe
54 Primary separation chamber (Droplet primary separation means)
55 Closure tube (secondary droplet separation means)
55b Blocking plate part (collision part; blocking plate)
58 Collision plate (wall surface)

Claims (4)

A low-pressure stage compressor body,
A cooler for cooling the compressed air compressed by the low-pressure stage compressor body;
Droplet primary separation that primarily separates droplets generated in the compressed air by cooling the cooler by colliding with a wall surface substantially perpendicular to the flow direction of the compressed air flowing in a substantially horizontal direction. Means,
A blocking plate provided above the droplet primary separating means and secondarily separating by colliding with a droplet that could not be separated by the droplet primary separating means was provided at the upper end of the cylindrical portion. A droplet secondary separation means comprising:
A lead-out pipe for deriving compressed air from which droplets have been separated by the closing pipe from outside the side of the cylinder portion of the closing pipe below the closing plate;
A discharge port which is located below the substantially vertical wall surface of the droplet primary separation means and discharges the droplets separated by the droplet primary separation means and the droplet secondary separation means;
A two-stage screw compressor comprising a high-pressure stage compressor body for further compressing compressed air from the outlet pipe.   2. The two-stage screw compressor according to claim 1, wherein the droplet primary separation means and the droplet secondary separation means are integrally formed. The two-stage screw compressor according to claim 1 or 2, wherein the droplet primary separation means is a cooler header provided integrally with the cooler,
The two-stage screw compressor is characterized in that the lead-out pipe is provided so as to penetrate from the outside of the side of the closing pipe to the inside.   4. The two-stage screw compressor according to claim 3, wherein the discharge port is provided at a bottom portion of an outlet chamber through which compressed air from the cooler flows in the cooler header. Compressor.

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