JP6266995B2 - Receiver tank with level gauge - Google Patents

Description

  The present invention relates to a receiver tank with a level gauge, and more specifically, introduces a compressed gas discharged as a gas-liquid mixed fluid with a cooling oil from a compressor body of an oil-cooled compressor, and includes the cooling oil contained in the compressed gas. The present invention relates to a receiver tank having a level gauge for displaying a liquid level position of cooling oil stored in the receiver tank.

  In an oil-cooled compressor, the compression action is performed while injecting oil (referred to as “cooling oil” in this specification) for the purpose of cooling, lubrication, and sealing in a gas such as air or gas sucked into the compressor body. As a result, the compressed gas discharged from the compressor body contains a large amount of cooling oil.

  Therefore, the oil-cooled compressor cannot supply the compressed gas discharged from the compressor body to the consumer side as it is, and removes the cooling oil from the compressed gas discharged from the compressor body before supplying it to the consumer side. Work is required.

  Therefore, in the oil-cooled compressor, the compressed gas discharged as a gas-liquid mixed fluid with the cooling oil from the discharge port of the compressor main body 150 is once introduced into the receiver tank 100 as shown in FIG. In the receiver tank 100, primary separation of the cooling oil contained in the compressed gas is performed, and the compressed gas from which the cooling oil has been separated by this primary separation is passed through the oil separator 160 and further contained in the compressed gas in the form of mist. After the cooling oil is removed, it can be supplied to the compressed gas consumption side to which an air working machine or the like is connected.

  On the other hand, the cooling oil separated from the compressed gas in the receiver tank 100 and accumulated at the bottom of the receiver tank 100 passes through an oil cooler or an oil filter (not shown) and is then introduced into the oil supply port of the compressor main body 150. By doing so, it is used again for lubrication, cooling and sealing of the compression working space.

  In the oil-cooled compressor configured as described above, the amount of the cooling oil stored in the receiver tank 100 may hinder the operation of the device if it is too large or too small. An appropriate amount of oil stored in the receiver tank 100 is determined in advance, and an upper limit of the coolant level stored in the receiver tank 100 so that the appropriate amount of cooling oil is stored in the receiver tank 100. A position HL and a lower limit position LL are determined.

  Then, by providing a level gauge 130 for displaying the liquid level position of the cooling oil stored in the receiver tank 100, the cooling oil displayed by the level gauge 130 during maintenance / inspection of the oil-cooled compressor is provided. The amount of oil stored in the receiver tank 100 is adjusted so that the liquid level is an appropriate amount between the above-described upper limit position HL and lower limit position LL.

  As shown in FIG. 9, the level gauge 130 provided in the receiver tank 100 is provided with an upper connection hole 131 formed through the side wall of the receiver tank 100 above the upper limit position HL of the liquid level. The lower connection hole 132 formed through the side wall of the receiver tank 100 is provided below the lower limit position LL of the liquid level, and attached to the upper connection hole 131 and the lower connection hole 132, respectively, outside the receiver tank 100. A visible portion 135 was formed between the joints (right angle elbows) 133 and 134 by attaching a transparent pipe such as a glass tube that can see through the cooling oil flowing into the internal flow path, and introduced into the visible portion 135. The liquid level position of the cooling oil stored in the receiver tank 100 can be confirmed by the liquid level position of the cooling oil. There is a (refer to Patent Documents 1 and 2).

  The primary separation of the cooling oil contained in the compressed gas in the receiver tank is that when the cooling oil is introduced into the receiver tank together with the compressed gas, the liquid cooling oil is placed at the bottom of the receiver tank due to the difference in specific gravity, and the compressed gas is It is carried out by utilizing the fact that it is separated and collected.

  On the other hand, in order to improve the primary separation performance in the receiver tank, a receiver tank configured to generate a swirling flow in the compressed gas introduced into the receiver tank has also been proposed (Patent Document 3).

  Thus, by rotating the compressed gas in the receiver tank, the cooling oil contained in the compressed gas in the form of fine oil droplets (for example, mist) is also subjected to centrifugal force during the rotation and receives the inner wall of the receiver tank. It is separated and recovered by colliding with the gas and falling on the oil reservoir at the bottom of the receiver tank through the inner wall, and the primary separation of the cooling oil contained in the compressed gas can be performed more efficiently.

Japanese Patent Laid-Open No. 08-247826 JP 60-192225 A JP 2004-52710 A

  In the receiver tank 100 including the level gauge 130 described with reference to FIG. 9, the liquid level position of the cooling oil stored in the receiver tank 100 can be confirmed from the outside of the receiver tank 100. By adjusting the oil amount so that the liquid level of the cooling oil stored in the receiver tank 100 is between the predetermined upper and lower limit positions according to the display, the appropriate amount of cooling oil can be maintained.

  However, in the level gauge having the above-described configuration, as shown in FIG. 10, when an air column is generated in the cooling oil in the visible portion 135, the cooling oil in the visible portion 135 is vertically divided by the air column. Thus, the liquid level position of the cooling oil stored in the receiver tank 100 cannot be accurately displayed.

  In addition, the air column generated in the cooling oil in the visible portion 135 is difficult to remove, and once the air column is generated, the air column remains in the visible portion 135 for a long time, while the liquid level is accurately displayed. Be disturbed.

  The generation of such an air column with respect to the cooling oil in the visible part 135 occurs when the cooling oil flows into the visible part 135 from the upper connection hole 131 provided in the side wall of the receiver tank 100 or from the lower connection hole 132. Occurs when gas (bubbles) is introduced into the visible part 135, and when such cooling oil flows or bubbles are introduced into the visible part 135 having a relatively small diameter, the gas (bubbles) is caused by the viscosity of the cooling oil. ) Is hindered from rising, and the gas is trapped in the cooling oil without replacing the gas (bubbles) with the cooling oil.

  Therefore, in order to prevent the formation of air columns in the cooling oil in the visible portion 135, the inflow of cooling oil through the upper connection hole 131 and the introduction of gas (bubbles) through the lower connection hole 132 are performed. It is necessary to suppress it.

  On the other hand, in order to improve the primary separation performance of the cooling oil contained in the compressed gas in the receiver tank as described above, in the receiver tank configured to generate a swirling flow in the compressed gas introduced into the receiver tank, the compressed gas The cooling oil introduced at the same time collides with the inner wall of the receiver tank, travels along the inner wall, and falls into the oil reservoir at the bottom of the receiver tank.

  Therefore, when the level gauge 130 having the structure described with reference to FIG. 9 is provided in this type of receiver tank, the cooling oil flows into the visible portion 135 through the upper connection hole 131 opened in the inner wall of the receiver tank. It is easy to form an air column in the cooling oil in the visible portion 135.

  Also, the cooling oil containing a large amount of bubbles introduced into the receiver tank together with the compressed gas is stored in the bottom of the receiver tank, so that the bubbles rise in the cooling oil and are discharged from the liquid surface. However, as described above, in the type of receiver tank that generates a swirling flow in the introduced compressed gas, a large amount of the just introduced into the receiver tank together with the compressed gas. Cooling oil containing air bubbles travels along the inner wall of the receiver tank and falls into the oil reservoir. When falling into the oil reservoir, the oil collides with the liquid surface and further entrains air bubbles in the cooling oil. Increase the bubble content of the cooling oil in the oil sump).

  Therefore, when the level gauge 130 having the structure described with reference to FIG. 9 is provided in such a receiver tank, the lower connection that opens at the inner wall of the receiver tank 100, that is, the portion containing the most bubbles in the cooling oil. Air bubbles are easily introduced into the holes 132, and in this respect as well, air columns are easily generated in the cooling oil in the visible portion 135.

  As described above, when the level gauge having the structure described with reference to FIG. 9 is provided as it is in the receiver tank having the configuration for generating the swirl flow in the compressed gas in the receiver tank, the liquid level is accurately displayed. Cannot be performed.

  Accordingly, the present invention has been made to eliminate the above-mentioned drawbacks, and even when applied to a receiver tank of a type in which the compressed gas discharged from the compressor body is introduced into the inside as a swirling flow, the transparent pipe An object of the present invention is to provide a receiver tank equipped with a level gauge capable of preventing air columns that cause erroneous display from occurring in the cooling oil in the visible portion constituted by the above.

  Hereinafter, means for solving the problem will be described together with reference numerals used in the embodiment for carrying out the invention. This code is used to clarify the correspondence between the description of the scope of claims and the description of the mode for carrying out the invention. Needless to say, it is used in a limited manner for the interpretation of the technical scope of the present invention. It is not a thing.

In order to achieve the above object, the receiver tank 1 with a level gauge of the present invention comprises:
Receiver tank body 2 which is a pressure vessel for introducing compressed gas discharged as a gas-liquid mixed fluid with cooling oil from an oil-cooled compressor body, and a liquid level of cooling oil stored in the receiver tank body 2 A level gauge 30 for displaying
The receiver tank body 2 is
An introduction port 11 provided at a position near the upper end on the outside of the side wall formed in a cylindrical shape;
A discharge port 13 for discharging the compressed gas from the introduction port 11 in the receiver tank body 2;
The inlet 11 and the outlet 13 communicate with each other, and the compressed gas introduced through the inlet 11 is guided so as to generate a swirling flow along the inner wall of the receiver tank body 2 to generate the discharge. A guide path 12 for discharging from the outlet 13;
The level gauge 30 is
An upper connection hole 31 formed through the side wall of the receiver tank body 2 above the upper limit position HL of the coolant level;
A lower connection hole 32 formed through the side wall of the receiver tank body 2 below the lower limit position LL of the coolant level;
Outside the receiver tank main body 2, a flow path is provided inside the upper connection hole 31 and the lower end is communicated with the lower connection hole 32, so that the cooling oil introduced into the flow path can be seen through. It has a visible part 35 such as a configured transparent pipe,
An upper extension pipe 36 protruding inward of the receiver tank body 2 from the upper connection hole 31 and / or a lower extension pipe 37 protruding inward of the receiver tank body 2 from the lower connection hole 32;
The openings 38 and 39 provided at the tip end portions (36a, 37a) of the upper extension pipe 36 and / or the lower extension pipe 37 are centered on the center O of the receiver tank body 2 in plan view, and the center O The discharge port 13 is arranged inside a circle C having a radius of a distance d between the inner peripheral side end portions 13a (Claim 1).

  The upper extension pipe 36 is preferably formed such that an opening 38 provided in the tip end portion 36a faces downward in the horizontal direction, and the lower extension pipe 37 is provided with an opening 39 provided in the tip end portion 37a. Is preferably formed so as to face upward with respect to the horizontal direction. (Claim 2: FIGS. 3B, 3C, and 5)

  In addition, an oil drain hole 38a that opens downward on the side surface of the upper extension pipe 36 at a position near the upper connection hole 31 with respect to the opening 38 provided in the distal end portion 36a of the upper extension pipe 36, preferably, It may be formed so as to be arranged in a circle C, and the side surface of the lower extension pipe 37 is positioned near the lower connection hole 32 with respect to the opening 39 provided in the tip end portion 37a of the lower extension pipe 37. An air vent 39a opened upward may be formed so as to be preferably disposed in the circle C (Claim 3; see FIG. 7).

  With the configuration of the present invention described above, the receiver tank 1 with a level gauge of the present invention employs a receiver tank body 2 having a structure for generating a swirling flow in the compressed gas introduced therein. Even in this case, the generation of air columns in the cooling oil in the visible portion 35 of the level gauge 30 can be suitably prevented.

  That is, by providing the upper extension pipe 36 having the above-described configuration, the opening position of the upper connection hole 31 inside the receiver tank body 2 can be extended inward of the receiver tank body 2 (the receiver tank body 2 of the receiver tank body 2). Even if the cooling oil falls along the inner wall of the receiver tank body 2 due to the centrifugal force associated with the generation of the swirling flow, the cooling oil can pass through the upper connection hole 31. Thus, it was possible to suitably prevent the liquid from flowing into the visible portion 35.

  In addition, the opening 38 provided in the distal end portion 36a of the upper extension pipe 36 is centered on the center O of the receiver tank body 2 in plan view, and the distance d between the center O and the inner peripheral side end portion 13a of the discharge port 13 is d. The tip 36a of the upper extension pipe 36 contains a large amount of cooling oil that is discharged from the discharge port 13 and moves along the inner wall of the receiver tank body 2. Since it is provided at a position deviating from the front of the flow direction of the compressed gas flow (see the arrow in FIG. 1), the cooling oil discharged through the discharge port 13 is directly applied to the tip of the upper extension pipe 36. It was possible to suitably prevent the liquid from flowing into the opening 38 provided in 36a.

  Furthermore, since the lower extension pipe 37 having the above-described configuration is provided, the opening 39 provided at the distal end portion 37a of the lower extension pipe 37 has the largest bubble content in the cooling oil accumulated at the bottom of the receiver tank body 2. Since it could be arranged near the center of the small oil reservoir, it was possible to prevent air bubbles from being introduced into the opening 39 provided in the distal end portion 37a of the lower extension pipe 37.

  A configuration in which the upper extension pipe 36 is formed so that the opening 38 provided in the distal end portion 36a of the upper extension pipe 36 faces downward in the horizontal direction, and the opening 38 provided in the distal end portion 36a of the upper extension pipe 36 is provided. In the configuration formed as a hole formed downward in the side surface of the distal end portion 36 a of the upper extension pipe 36, the cooling oil discharged together with the compressed gas through the discharge port 13 temporarily enters the distal end portion 36 a of the upper extension pipe 36. Even if it falls directly, the opening 38 provided in the tip portion 36a is provided downward so that the cooling oil can be suitably prevented from flowing into the opening 38.

  Further, the opening 39 provided at the tip portion 37a of the lower extension tube 37 has a configuration in which the lower extension tube 37 is formed so as to face upward in the horizontal direction, and the opening 39 of the tip portion 37a of the lower extension tube 37 is formed. In the configuration formed as an upwardly formed hole in the side surface of the lower extension pipe 37 in the tip portion 37a, the bubble floating in the cooling oil passes through the vicinity of the opening 39 provided in the tip portion 37a of the lower extension pipe 37. Even in such a case, it was possible to suitably prevent bubbles from being introduced into the opening 39.

  Further, in the configuration in which the above-described oil drain hole 38a is provided in the upper extension pipe 36, even if the cooling oil flows into the upper extension pipe 36 through the opening 38, the cooling oil When moving toward the visible portion 35 through the inside 36, it always passes over the oil drain hole 38a and is discharged through the oil drain hole 38a, so that the visible portion 35 is cooled via the upper extension pipe 36. It was possible to more reliably prevent the oil from being introduced.

  Further, in the configuration in which the above-described bubble vent hole 39a is provided in the lower extension tube 37, even if the bubble is introduced into the lower extension tube 37 through the opening 39, the bubble is transferred to the lower extension tube 37. When moving toward the visible portion 35, it always passes under the bubble vent 39 a, and is floated and discharged in the cooling oil through the bubble vent 39 a, so that the lower extension pipe 37. The bubbles introduced into the inside could be discharged before reaching the visible portion 35.

The plane perspective view of the receiver tank with a level gauge of the present invention. The front perspective view of the receiver tank with a level gauge of this invention. It is explanatory drawing which shows the modification of an upper extension pipe and a lower extension pipe, (A) is the structure which narrowed down the front-end | tip part, (B) is the structure which cut the front-end | tip part diagonally, (C) is the side surface of a front-end | tip part. The form which formed the opening is shown. The plane perspective view of the receiver tank with a level gauge of this invention which shows the modification of the front-end | tip part of an upper extension pipe and a lower extension pipe. The front perspective view of the receiver tank with a level gauge of this invention which shows the modification of the front-end | tip part of an upper extension pipe and a lower extension pipe. The plane perspective view of the receiver tank with a level gauge which shows another modification of the front-end | tip part of an upper extension pipe and a lower extension pipe. The front perspective view of the receiver tank with a level gauge which shows another modification of the front-end | tip part of an upper extension pipe and a lower extension pipe. The top perspective view of the receiver tank with a level gauge which shows another modification of the front-end | tip part of an upper extension pipe and a lower extension pipe. Explanatory drawing which shows the whole structure of an oil-cooled compressor. Explanatory drawing of the generation | occurrence | production state of the air column in the visible part of a level gauge.

  Hereinafter, a receiver tank 1 with a level gauge according to the present invention will be described with reference to the accompanying drawings.

  In FIG. 1, reference numeral 1 denotes a receiver tank with a level gauge of the present invention.

  The receiver tank 1 with a level gauge includes a receiver tank body 2 that is a pressure vessel having a cylindrical side wall, and a level gauge 30 that displays a liquid level position in an oil reservoir 15 at the bottom of the receiver tank body 2.

  The above-described receiver tank main body 2 employed in the receiver tank 1 with a level gauge of the present invention includes a swirling flow generating means 10 that generates a swirling flow in the compressed gas introduced therein.

  The swirling flow generating means 10 includes an inlet 11 provided at a position near the upper end outside the side wall of the receiver tank body 2, and a discharge for discharging the compressed gas introduced through the inlet 11 into the receiver tank body 2. When a compressed gas from a compressor body (not shown) is introduced into the inlet 11, the outlet 13 is connected to the receiver 11 through the inlet 12 and communicates between the inlet 11 and the outlet 13. The tank body 2 is configured to be guided to generate a swirling flow along the inner wall of the tank body 2 and to be discharged from the discharge port 13.

  In the illustrated embodiment, the above-described guide path 12 is formed as a flow path that connects the introduction port 11 and the discharge port 13 in a straight line, and in the plan view of the receiver tank 1 shown in FIG. Is provided at a position parallel to and close to the tangent TL to the circle drawn by the inner wall of the receiver tank body 2 to guide the introduced compressed gas along the inner wall of the receiver tank body 2 and swivel. The flow can be generated.

  In the example shown in FIG. 1, the case where the guide path 12 is formed as a linear flow path has been described as an example. However, the guide path 12 is configured so that the compressed gas introduced into the receiver tank body 2 is received by the receiver tank. As long as it can be guided to generate a swirling flow along the inner wall of the main body 2, various modifications are possible without being limited to the illustrated configuration. For example, a receiver tank such as a receiver tank previously introduced as Patent Document 3 can be used. A curved guiding path formed along the inner wall surface of the tank body 2 may be provided (see FIGS. 2, 3, and 5 of Patent Document 3).

  The above-described level gauge 30 provided in the receiver tank 1 is an upper connection hole formed through the side wall of the receiver tank body 2 at an upper position with respect to the liquid level upper limit position HL of the cooling oil stored in the receiver tank body 20. 31, a lower connection hole 32 formed through the side wall of the receiver tank body 2 at a position below the liquid level lower limit position LL of the stored cooling oil, and an upper end at the upper connection hole 31 outside the receiver tank body 2 Is connected to the lower connection hole 32, and has a visible portion 35 formed by attaching a member that can see through the cooling oil introduced into the internal flow path, such as a transparent pipe. This is common with the conventional level gauge described with reference to FIG.

  In the illustrated embodiment, the visible portion 35 described above is formed of a transparent pipe such as a glass tube, and the upper end of the transparent pipe 35 is connected to the lower connection to a joint (right angle elbow) 33 attached to the upper connection hole 31. The transparent pipe (visible part) 35 is connected to the upper connection hole 31 and the lower connection hole 32 by connecting the lower end of the transparent pipe 35 to the joint (right angle elbow) 34 attached to the hole 32. The configuration of the visible portion 35 is not limited to that using a transparent pipe. For example, the visible portion 35 may be a metal cylinder (cylindrical or square cylinder) in which a transparent plate is fitted to form a window through which the internal flow path can be seen. The visible portion 35 may be formed by connecting the upper and lower ends of the cylindrical body to the upper connection hole 31 and the lower connection hole 32 directly or via a joint or the like.

  The level gauge 30 provided in the receiver tank 1 of the present invention further includes one or both of the above-described upper connection hole 31 and lower connection hole 32 in the receiver tank body 2 (both in the illustrated example), An extension pipe (upper extension pipe 36, lower extension pipe 37) extending inward of the receiver tank body 2 is provided, and openings provided at the distal ends 36a, 37a of the extension pipes (upper extension pipe 36, lower extension pipe 37). As shown in FIG. 1, the circles 38 and 39 are centered on the center O of the receiver tank main body 2 in plan view, and the radius C is a distance d between the center O and the inner peripheral side end 13a of the discharge port 13. It is provided inside.

  In the illustrated embodiment, the upper extension pipe 36 and the lower extension pipe 37 are formed of a pipe material formed separately from the joints 33 and 34 that are the right angle elbows described above, and one end of the pipe material is used as the receiver tank body 2. However, the extension pipes 36 and 37 may be formed integrally with the joints 33 and 34, respectively. Alternatively, the level gauge 30 may be attached directly to the connection holes 31 and 32 formed on the side wall of the receiver tank body 2 by welding or other methods without being attached to the joints 33 and 34. If the communication position is inward from the inner wall of the receiver tank body 2 and can extend to the inside of the circle C described above, Formed is not particularly limited.

  In the example shown in FIGS. 1 and 2, the upper extension pipe 36 and the lower extension pipe 37 are formed to have a constant diameter over the entire length, and the tips thereof are respectively axis lines of the upper extension pipe 36 and the lower extension pipe 37. However, instead of this configuration, the tip portions 36a, 37a of the upper extension pipe 36 and the lower extension pipe 37 are narrowed as shown in FIG. 3 (A). As shown in FIG. 3B, the upper extension tube 36 is cut obliquely so that the opening 38 faces downward and the lower extension tube 37 faces the opening 39 upward. Alternatively, as shown in FIG. 3 (C), the tip of the upper extension tube 36 is closed and a downward hole is formed in the side surface of the tip portion 36a to form an opening 38, thereby forming a lower extension tube 37. When closing the tip of , Which may be used as the opening 39 to form a side surface in an upward bore in the tip portion 37a.

  As described above, the tip portions 36a and 37a of the upper extension tube 36 and the lower extension tube 37 are drawn (see FIG. 3A), or obliquely cut (see FIG. 3B), or the tips are By closing and forming a hole in the side surface of the extension pipe (see FIG. 3C), the cooling oil is opened in the upper extension pipe 36 even when the cooling oil falls on the tip 36a from above. 38, and it is difficult for the lower extension pipe 37 to be trapped in the opening 39 even when bubbles rising in the cooling oil come into contact with the tip 37a. it can.

  Similarly, as shown in FIG. 5, the upper extension pipe 36 can be prevented from inflowing the cooling oil into the opening 38 by bending the tip portion 36a downward with respect to the horizontal direction.

  Further, as shown in FIG. 5, the lower extension pipe 37 can be prevented from introducing bubbles into the opening 39 by curving the tip portion 37 a upward with respect to the horizontal direction.

  In order to allow the cooling oil to flow out through the opening 38 provided at the distal end portion 36a of the upper extension pipe 36 so that it can be discharged out of the upper extension pipe 36, An oil drain hole 38 a that opens downward may be provided on the side surface of the upper extension pipe 36 at a position near the upper connection hole 31 with respect to the opening 38.

  By providing such an oil drain hole 38a, even if the cooling oil flows in through the opening 38 provided in the distal end portion 36a of the upper extension pipe 36, the flowing cooling oil is not visible. Even when the cooling oil flows into the upper extension pipe 36 through the opening 38 when passing through the oil drain hole 38a during the movement toward the pipe 35, the cooling oil flows into the upper extension pipe 36. The visible part 35 is not reached.

  Similarly, the lower extension pipe 37 is also provided with a bubble vent hole 39a that opens upward on the side surface near the lower connection hole 32 with respect to the opening 39 provided in the tip end part 37a. Even when air bubbles are introduced through the opening 39 provided at the distal end portion 37a of the air 37, the introduced air bubbles are outside the lower extension pipe 37 through the air bubble vent 39a before reaching the visible portion 35. It can be made to be discharged.

  The oil drain hole 38a and the bubble vent hole 39a are similar to the opening 38 provided at the distal end portion 36a of the upper extension tube 36 and the opening 39 provided at the distal end portion 37a of the lower extension tube 37, in a receiver tank in plan view. The center 2 is preferably provided inside a circle C centered on the center O of the main body 2 and having a radius d between the center O and the inner peripheral side end 13a of the discharge port 13.

  Depending on the formation position and the formation angle of the upper connection hole 31 and the lower connection hole 32, the distal end portions 36a and 37a may be disposed inside the circle C by attaching the linear extension pipes 36 and 37. In this case, as shown in a plan view in FIG. 8, all or part of the upper extension pipe 36 and the lower extension pipe 37, and the tip ends 36 a, 37 a are on the center O side of the receiver tank body 2. It may be configured such that the openings 38 and 39 formed in the tip portions 36a and 37a are arranged on the inner side of the circle C by being curved so as to approach each other.

  In the above description, the configuration in which both the upper extension tube 36 and the lower extension tube 37 are provided has been described. However, only one of the upper extension tube 36 and the lower extension tube 37 may be provided.

  In the above description, the tip shapes of the upper extension tube 36 and the lower extension tube 37 have been described as corresponding to each other. However, the tip shape of the upper extension tube 36 and the lower extension tube 37 The tip shapes do not need to correspond to each other, and may be adopted by appropriately combining the various shapes described above.

  As described above, by providing the upper extension pipe 36 that protrudes inward of the receiver tank body 2 from the upper connection hole 31 provided in the side wall of the receiver tank body 2, the distal end portion 36a of the upper extension pipe 36 is provided. This is the case where the level gauge 30 is provided in the receiver tank 1 which can be arranged away from the side wall of the receiver tank body 2 and the receiver tank 1 configured to generate a swirling flow in the compressed gas introduced therein. However, the cooling oil flowing along the inner wall of the receiver tank body 2 does not flow into the visible portion 35 through the opening 38 provided in the tip portion 36a of the upper extension tube 36, and the tip of the upper extension tube 36 The flow of the compressed gas containing a large amount of cooling oil introduced into the receiver tank body 2 through the guide path 12 by arranging the opening 38 provided in the portion 36a inside the circle C described above. An opening 38 provided at the tip 36a of the upper extension pipe 36 can be provided at a position deviated from the front of the direction (see the arrow in FIG. 1), and the cooling oil in the compressed gas directly flows into the upper extension pipe 36. It was also possible to prevent inflow into the opening 38 provided in the tip portion 36a.

  In particular, as shown in FIG. 3 (A), the tip end portion 36a of the upper extension tube 36 is narrowed, and as shown in FIGS. 3 (B), 3 (C), and 5, the tip end portion of the upper extension tube 36 is shown. In the configuration in which the opening 38 provided in 36 a is provided downward, even if the cooling oil falls on the tip 36 a of the upper extension pipe 36, it is difficult for the cooling oil to flow into the opening 38.

  On the other hand, in the configuration in which the lower extension pipe 37 having the above-described configuration is provided, in the oil reservoir 15 at the bottom of the receiver tank body 2, the bubble content is the smallest, and the tip portion 37 a of the lower cooling pipe 37 is located near the center. Since the provided opening 39 is arranged, the introduction of bubbles through the opening 39 of the lower extension pipe 37 can be suitably prevented.

  That is, bubbles in the cooling oil accumulated at the bottom of the receiver tank main body 2 are removed with the passage of time as they float in the cooling oil and escape from the liquid surface as time elapses. In the receiver tank of the type in which a swirl flow is generated in the compressed gas in the inside, the cooling oil containing a large amount of air bubbles just introduced into the receiver tank together with the compressed gas travels along the inner wall surface of the receiver tank body 2 in the oil reservoir 15. As a result, the bubble content in the vicinity of the inner wall of the receiver tank body 2 of the oil reservoir 15 is increased.

  Moreover, since the cooling oil that has fallen along the inner wall collides with the liquid surface when flowing into the oil reservoir 15, gas is entrained in the cooling oil, and also in this respect, the vicinity of the inner wall of the receiver tank body 2 of the oil reservoir 15 Increase the bubble content in.

  In addition, when the compressed gas flow is swirled in the receiver tank main body 2, the cooling oil in the oil reservoir 15 at the bottom of the receiver tank main body 2 is also swirled in the same swiveling direction.

  However, the swirling of the cooling oil generated in this way has a relatively low rotational speed, and air bubbles that can become air columns when introduced into the visible portion 35 (the air bubbles to be prevented from entering the lower extension pipe 37 in the present application). ) Has a relatively large size of several millimeters to 1 cm, and therefore has a strong buoyancy in the cooling oil. Unlike microscopic bubbles, the time spent in the cooling oil is relatively short, and the viscosity of the cooling oil Therefore, even if a slight centrifugal force is applied to the cooling oil due to swirling, the bubbles in the cooling oil float up in the cooling oil and are released from the liquid level before moving to the center of the receiver tank. Therefore, the cooling oil near the center of the oil reservoir 15 is maintained in a state where the bubble content is low.

  As a result, as described above, the distal end portion 37a of the lower extension tube 37 is extended inward of the receiver tank body 2 from the lower connection hole 32 to the inner side of the circle C described above, whereby the distal end of the lower extension tube 37 is obtained. The opening 39 provided in the portion 37a can be disposed in the portion of the cooling oil collected in the oil reservoir 15 with the least amount of bubbles, and the opening 39 provided in the tip portion 37a of the lower extension pipe 37 is provided through the opening 39. The introduction of air bubbles that could be generated in this way could also be suitably prevented.

  In particular, as shown in FIG. 3 (A), the distal end portion 37a of the lower extension tube 37 is narrowed, and as shown in FIGS. 3 (B), 3 (C), and 5, the distal end portion of the lower extension tube 37 is shown. In the configuration in which the opening 39 provided in the upper portion 37a is provided upward, the opening 39 collects the bubbles even when the air bubbles floating in the cooling oil come into contact with the tip portion 37a of the lower extension pipe 37. It was difficult to introduce bubbles more reliably.

  As shown in FIGS. 6 and 7, in the configuration in which the oil extension hole 38 a is provided in the upper extension pipe 36 and the bubble release hole 39 a is provided in the lower extension pipe 37, Even when cooling oil flows into the extension pipe 36 and bubbles are introduced into the lower extension pipe 37 through the opening 39, the introduced cooling oil or introduced bubbles reach the visible portion 35. Could be discharged before.

  In particular, the oil drain hole 38a is centered on the center O of the receiver tank body 2 in plan view, and inside the circle C having a radius of the distance d between the center O and the inner peripheral side end 13a of the discharge port 13. In the arrangement, the flow direction of the compressed gas flow containing a large amount of cooling oil discharged from the discharge port 13 and moving along the inner wall of the receiver tank body 2 through the oil drain hole 38a (in FIG. 1). The cooling oil discharged through the discharge port 13 can be prevented from directly reaching the oil drain hole 38a, and the oil drain hole 38a is directed downward. In combination with the opening, it was possible to suitably prevent the cooling oil from flowing into the upper extension pipe 36 through the oil drain hole 38a.

  Similarly, in the configuration in which the bubble vent hole 39a is arranged in the circle C, the bubble vent hole 39a can be opened at the portion where the bubbles are the least in the oil reservoir 15, and the bubble vent hole 39a is opened upward. In combination with this, it was possible to prevent bubbles from being introduced into the lower extension pipe 37 through the bubble vent 39a.

  As described above, by providing the upper extension pipe 36 and / or the lower extension pipe 37 having the above-described configuration, it is possible to reliably prevent air columns from being generated in the cooling oil in the visible portion 35 that may cause erroneous display. I was able to.

1 Receiver tank (receiver tank with level gauge)
2 receiver tank body 10 swirl flow generating means 11 introduction port 12 guide path 13 discharge port 13a inner peripheral side end (of discharge port)
15 Oil reservoir 30 Level gauge 31 Upper connection hole 32 Lower connection hole 33, 34 Joint (right angle elbow)
35 Visible part (transparent pipe)
36 Upper extension pipe 36a Tip (of the upper extension pipe)
37 Lower extension pipe 37a Tip (of the lower extension pipe)
38, 39 Opening 38a Oil drain hole 39a Bubble vent hole HL Upper limit position of liquid level LL Lower limit position of liquid level O Center of receiver tank body d Distance between center O of receiver tank body and inner peripheral side end 13a of discharge port C Circle with center O of receiver tank body and radius d as distance TL Tangent line to circle drawn by inner wall of receiver tank body 100 Receiver tank 130 Level gauge 131 Upper connection hole 132 Lower connection hole 133, 134 Pipe fitting (right angle elbow )
135 Visible part 150 Compressor body 160 Oil separator

Claims (3)

The receiver tank body, which is a pressure vessel that introduces compressed gas discharged as a gas-liquid mixed fluid with cooling oil from the oil-cooled compressor body, and the liquid level of the cooling oil stored in the receiver tank body are displayed. Equipped with a level gauge to
The receiver tank body is
An introduction port provided at a position near the upper part outside the side wall formed in a cylindrical shape;
A discharge port for discharging compressed gas from the introduction port in the receiver tank body;
The introduction port communicates with the discharge port, and the compressed gas introduced through the introduction port is guided to cause a swirling flow along the inner wall of the receiver tank body and discharged from the discharge port. With taxiway,
The level gauge is
An upper connection hole formed through the side wall of the receiver tank body above the upper limit position of the coolant level;
A lower connection hole formed through the side wall of the receiver tank body below the lower limit position of the coolant level;
Outside the receiver tank body, the upper end is connected to the upper connection hole and the lower end is connected to the lower connection hole, and the cooling oil introduced into the flow path can be seen through. With a visible part,
An upper extension pipe projecting inward of the receiver tank body from the upper connection hole, and / or a lower extension pipe projecting inward of the receiver tank body from the lower connection hole,
The opening provided at the tip of the upper extension pipe and / or the lower extension pipe is centered on the center of the receiver tank body in plan view, and the distance between the center and the inner peripheral end of the discharge port is A receiver tank with a level gauge, which is placed inside a circle with a radius. Forming the upper extension pipe so that the opening provided at the tip of the upper extension pipe faces downward in the horizontal direction;
The receiver tank with a level gauge according to claim 1, wherein the lower extension pipe is formed so that an opening provided at the tip of the lower extension pipe faces upward in a horizontal direction. An oil drain hole that opens downward on the side surface of the upper extension pipe is formed at a position near the upper connection hole with respect to the opening provided at the tip of the upper extension pipe,
2. A bubble vent hole opened upward is formed in a side surface of the lower extension pipe at a position near the lower connection hole with respect to an opening provided at the tip of the lower extension pipe. Receiver tank with level gauge.

Images