JPH02290495A - Air cooler of oil-free type screw air compressor - Google Patents

Abstract

PURPOSE:To simplify a piping and thereby to improve operability by a construction wherein first and second headers are fitted on the opposite sides of a body, first to fifth chambers are provided for the first header, sixth and seventh chambers communicating with the second header are provided, and a pre-cooler element, a blow-off cooler element and an after-cooler element are made to communicate with the first and sixth chambers, the sixth and third chambers and the second and seventh chambers respectively, while a circulation space is made to communicate with the fourth and fifth chambers. CONSTITUTION:A first header 14 has first to fifth chambers 17 to 21 inside, a small- diameter trunk 29 fitted with a check valve 28 is provided inside a second header 15, and a sixth chamber 30 is formed inside the trunk, while a seventh chamber 31 is formed outside the same. A pre-cooler element 16a in a heat exchanger pipe group 16 is made to communicate with the first chamber 17 of the first header 14 and the sixth chamber 30 of the second header 15, an after-cooler element 16b to the second chamber 18 and the seventh chamber 31, and a blow-off cooler element 16c to the third chamber 19 and the sixth chamber 30, respectively. A pipe plate 13 is provided with a first through hole 32 and second through hole 33, which are made to communicate with the fourth chamber 20 and the fifth chamber 21 of the first heater 14 respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an air cooler for an oil-free screw air compressor.

(Prior art) Conventionally, in a screw air compressor (hereinafter referred to as a compressor), high-temperature, high-pressure compressed air discharged from the compressor body is sent to the consumption point via a check valve, and air cooling is performed. The compressed air is lowered to a predetermined temperature using a device.

In addition, in the so-called purge method, in which the intake valve is closed and the discharged air is discharged when the amount of air used at the compressed air consumption point decreases, the capacity of the compressed air to be discharged, that is, the compressor body and check valve It is preferable to provide a check valve immediately after the outlet of the compressor main body because the smaller the capacity between the compressor and the compressor, the lower the power loss.

However, like an oil-free compressor, one stage has a 7.0
When compressing to kg/cmtG and the discharge temperature is 350℃ or higher, use a check valve (heat resistant
℃) in an atmosphere at this discharge temperature, the valve body and spring will no longer function as they are used repeatedly. For example, the seat surface of the valve becomes worn, and the valve body no longer comes into close contact with the seat surface, making it impossible to prevent backflow. Furthermore, if high-temperature compressed air is directly blown outside the machine, it may be dangerous and cause various other problems. Therefore, it is necessary to install an air cooler between the compressor main body and the check valve.

Therefore, by separating the air cooler into a pre-cooler and an after-cooler, and installing a pre-turner between the compressor body and the check valve, the high-temperature compressed air discharged from the compressor body is primarily cooled in the pre-cooler. Then, during a-do operation, the compressed air is led to an aftercooler for further cooling and sent out, while during unloading, the primarily cooled compressed air is released through the check valve to prevent the check valve from being exposed to high temperatures. It is set as.

FIG. 7 shows an air and cooling water system diagram of a conventional oil-free compressor, in which a pre-cooler 2 and an after-cooler 4 are separately provided on the discharge side of the compressor body 1. And the compressed air discharged from the compressor main body l, for example 7.0k
g/cm"G, 3 5 After the compressed air at 0°C is primarily cooled to 150 to 200°C in the precooler 2, the check valve 3
After that, it is cooled down to 45° C. in an aftercooler 4, and then sent under pressure to a consumption point (not shown). In addition, it branches between the compressor main body I and the pre-cooler 2, and the pre-cooler 2
A blowoff line is provided that opens to the atmosphere through a blowoff cooler 2a inside the pre-cooler 2 and a blowoff valve 5, and when blowing air, the compressed air that has been primarily cooled by the blowoff cooler 2a inside the pre-cooler 2 is released into the atmosphere. It's supposed to be windy. In addition, 6 is a safety valve, 7
is the intake valve.

(Problem to be Solved by the Invention) In the conventional device, the pre-cooler 2 and the after-cooler 4
It is set up separately and independently. For this reason, this device requires air piping and cooling water piping between both taras, which not only complicates the piping, but also increases the piping space within the device, making the device bulky and requiring a large installation space. The problem is that it is necessary.

On the other hand, precooler 2. It is conceivable to form the check valve 3 and the aftercooler 4 in the same case song.

In this case, a large number of heat exchanger tube groups are arranged in parallel within the casing. In this respect, there is a known example shown in Japanese Utility Model Application Laid-Open No. 57-77672.

However, the device described in this publication is a shell-and-tube heat exchanger, and even though many tubes are arranged in parallel, it merely has one pass. Regarding the cooler 4, although there is a possibility of application to improve the heat exchange rate, the precooler 2. has a different function. There is a problem in that it cannot be applied to a line on the discharge side of a compressor that includes three devices, a check valve 3 and an aftercooler 4, and has multiple paths (a path to a consumption point and a path for blowing air).

In other words, each device described in the above publication has a meandering flow path, that is! The only difference is in the arrangement method of the plurality of pipes that make up the path.Excluding this difference in arrangement method, the precooler 2. after. - There is basically no difference from each cooler 4 as a single cooler, and all of them are simply provided with I types of paths in the same casing. Therefore, it cannot be applied to the above-mentioned compressor which requires a branch-and-failure type path and a reverse valve on the discharge side line.

The present invention has been made to address these conventional problems, and is therefore a pre-cooler. By housing the discharge side line, including the aftercooler and air cooler, in the same casing, the functions of each part of the device are not compromised, the piping is simplified, the installation space is reduced, and manufacturing and maintenance inspections are not time-consuming. It is an object of the present invention to provide an air cooler for an oil-free compressor with a structured structure.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides first tubes on both sides of a body whose ends are closed with tube plates. A second header is attached, and a group of heat transfer tubes consisting of a plurality of tubes arranged in a pre-cooler section, an after-cooler section, and an air blowing cooler section are installed in the fluid circulation space inside the body by penetrating the tube sheet. With,
The first header has a first chamber that is a compressed air inlet, a second chamber that is a compressed air outlet, and a third chamber that is a discharge air outlet;
A fourth chamber, which is a cooling fluid inlet, and a fifth chamber, which is a cooling fluid outlet, are provided with a sixth chamber and a seventh chamber, which communicate with the second header via a check valve, and the precooler section is connected to a chamber I. and in the 6th room,
The air discharge cooler section is communicated with the sixth and third chambers, the aftercooler section is communicated with the second and seventh chambers, and the fluid circulation space is communicated with the fourth chamber through through holes provided in the tube plate. and the fifth
It was formed by communicating with the chamber.

(Function) By forming it as described above, a pre-cooler reverse valve can be created. The aftercooler and air blower cooler are housed in the same casing, greatly simplifying piping, reducing installation space, and reducing labor during manufacturing and maintenance.

In addition, since a check valve is provided at the outlet of the pre-cooler section,
The amount of air blown during air blowing is kept to a minimum, and check valve corrosion due to condensate generated from compressed air is also eliminated.

Furthermore, all the piping parts are concentrated in the first header part, and there is no piping connection part in the second header on the check valve side.

(Example) Next, one embodiment of the present invention will be described with reference to the drawings.

1 to 5 show the air cooler II of the oil-free compressor according to the present invention, in which both ends of the body 12 are connected to the tube plate 13.
13a, and in FIG. 1, a first header l4 is removably attached to the right side of the tube plate I3, and a second header 15 is detachably attached to the left side of the tube plate 13a. A heat exchanger tube group I6 consisting of a plurality of tubes is arranged in parallel inside the tube plate 2, passing through the tube plates 13 and 13a.

As shown in FIG. 1, the tube plate 13a is slidably fitted into the end of the body l2 via a sealing means S.

As shown in FIG. 2, the first header I4 includes a first chamber +7, a second chamber 18, a third chamber 19, a fourth chamber 20 and a fifth chamber.
It has 2 l chambers, each chamber leading to external piping attached to nozzles 22, 23, 24, 25 and 26, and a second chamber 1
8 is further provided with a safety valve mounting seat 27. In addition, the nozzle stand 22. The nozzle 25 is a common nozzle as shown in FIG.

Inside the second header 15, as shown in FIG. The 6th room is 30. A seventh chamber 3l is formed outside.

As shown in FIG. 4 and FIG. 5, the heat exchanger tube 1nl6 includes a pre-cooler section 16a. It consists of an aftercooler +6b and a blowout cooler16c. In FIG. 5, in order to clearly show these parts, the heat exchanger tubes constituting each section are connected with solid lines. Then, the pre-cooler 16a is placed in the first chamber 17 of the first header 14 and the sixth chamber 30 of the second header 15, and the after-cooler 16a is placed in the first chamber 17 of the first header 14 and the sixth chamber 30 of the second header 15. 6b communicates with the second chamber 18 and the seventh chamber 31, and the ventilation cooler section 16c communicates with the third chamber and the sixth chamber 30, respectively.

As shown in FIG. 5, the tube sheet 13 has a pre-cooler section 16.
The first through hole 32.a is located below the first through hole 32. A second through hole 33 is provided above the aftercooler part 16b, and each of the second through holes 33
It communicates with the fourth chamber 20 and fifth chamber 2I of the header I4.

Inside the body 12, as shown in FIG. 1, a plurality of baffle plates 34 are arranged in the longitudinal direction of the heat exchanger tube group 16 at appropriate intervals and arranged in a row. A water return pipe 35 extends from the second through hole 33 of the tube sheet l3 to the final baffle plate 34a closest to the tube sheet 13a, so as to guide the cooling water from the tube sheet 13a side to the fifth chamber 21. It is formed in

Air cooler consisting of the above configuration 1. 1 is functionally the same and is different from the one that simply integrates the pre-cooler (meaning the one that does not include the air cooler) and the after-cooler located on the first bus, and the after-cooler part +6b side. The discharge side part of the compressor, including the air discharge cooler 16c branched from the line and the check valve 28, which has a completely different function from cooling, is housed in the same casing and integrated without impairing the functions of each part. It is. Specifically (as mentioned above, for example, compressed air at 350°C
The compressed air is primarily cooled to 150 to 200 degrees Celsius in the precooler section 16a, cooled to about 45 degrees Celsius in the aftercooler section 16b, and then pumped to the consumption point. The stop valve 28 is in a temperature range where it does not receive damage due to heat, and the aftercooler section 16
In b, there is one temperature range in which condensate occurs. In the case of this device, the check valve 28 is installed on the side of the pre-trough portion 16a that is not exposed to drain or high heat, thereby ensuring its normal operation. On the other hand, if the check valve 28 is installed in another position, for example on the side of the aftercooler section 16b, the check valve 28 will corrode due to drainage and its life will be shortened.

By ensuring the normal operation of the check valve 2g, even when the compressor is unloaded, the aftercooler 16b
While reliably preventing the backflow of compressed air from the side, the compressed air that has been primarily cooled in the pre-cooler 16a is transferred to the air cooler section 1.
At 6c, further cooling is performed and air is discharged. Further, as described above, it is preferable that the amount of compressed air to be discharged is as small as possible, and a check valve 28 is installed in the artificial part of the pre-teller part 16a.
By providing this, the amount of air discharged is reduced.

On the other hand, another position, for example aftercooler part +6
If the check valve 28 is installed on the b side, the compressed air in the second header 15 will also be blown out, and this second header l
Since the volume within 5 cannot be made too small in order to ensure a smooth flow of the discharged compressed air, the amount of air discharged becomes large. As mentioned above, by housing the pre-cooler section 16a etc. in the same caning and integrating them, piping between each cooler and check valve becomes unnecessary, and it is possible to save time during manufacturing. This reduces the hassle of maintenance and inspection work, and also reduces the installation space. Further, in this air cooler l1, all nozzles are concentrated in one first header 14 to form a common header. In other words, simply integrating the pre-tara and the aftercooler will not solve the problem.
As in the heat exchanger described in Japanese Patent No. 672, the connection portions with external piping are scattered over the entire circumference. Further, a nozzle holder is provided in the body l2, and fluid enters and exits through an external pipe connected to the nozzle holder. On the other hand, in the air cooler 1l, not only the compressed air but also the cooling water are connected to external piping, that is, all the nozzle stubs are concentrated in the first header l4. For example, a first through hole 32 and a second through hole 33 to which a water return pipe 35 is attached are provided in the tube plate l3, and the first through hole 33 is
By forming a fourth chamber 30 and a fifth chamber 2l communicating with these through holes in the header l4, the first header I
Fluid can flow in and out of the body 12 by simply connecting external piping to the nozzles 25 and 26 provided in the body 12. Therefore, the piping to the air cooler 1l is in one place, namely the first header! 4, and the piping is simplified. Further, the tube plate 13a, which is one fixed part of each cooler part, is completely independent of the connection point with the external piping and is provided so as to be freely slidable, so that the tube plate 13a which is one of the fixed parts of each cooler part is provided so as to be able to slide freely. Since it can freely respond to expansion and contraction, even if vibration, thermal expansion, etc. occur in the main body of the air cooler 11, no vibration or thermal stress will occur in the piping. Furthermore, there is no need to remove the piping even during maintenance and inspection of each tarpaulin part of the air cooling ill and the check valve 28.

FIG. 6 shows an oil-free compressor to which the air cooler 11 according to the present invention is applied, and parts common to those in FIGS. 1 to 5 are shown with the same numbers, so A discharge line b from the compressor main body l, a supply line c leading to a consumption point (not shown) in the second chamber l8, an air discharge line d having a discharge valve 5 in the third chamber l9, a fourth chamber 20 and a fifth chamber 21 cooling line e. e' is connected.

The safety valve 6 is attached to a nozzle 27 provided in the second chamber 18, but is shown on the supply line C in FIG. 6 for convenience to avoid complicating the drawing.

The cooling water that has flowed into the fourth chamber 20 flows into the body l2, sequentially detours between the baffle plates 34, acts as a cooling medium, and flows out from the fifth chamber 21 through the inside of the water return pipe 35. .

Therefore, the air sucked into the compressor main body 1 through the intake line a having the intake valve 7 is compressed to a predetermined pressure, flows through the discharge line b into the first chamber l7 of the air cooler l1, and enters the precooler l7. It is cooled in the section 16a, flows from the sixth chamber 30 into the seventh chamber 3l via the check valve 28, is further cooled in the aftercooler section tab, and then passes through the supply line C from the second chamber I8 for consumption. sent to the location.

In addition, when compressed air is discharged during unloading, the compressed air is cooled in the pre-cooler section 16a and reaches the discharge cooler 16c from the sixth chamber 30 without passing through the check valve 28, where it is further After being cooled, air is blown out from the third chamber 19 through the air blowing line d.

(Effects of the Invention) As is clear from the above description, according to the present invention, first and second headers are attached to both sides of a body whose ends are closed with tube sheets, and a precooler is installed in a fluid circulation space inside the body. Department. Aftercooler section. A group of heat transfer tubes consisting of a plurality of tubes arranged in separate areas is provided in the ventilation cooler section, penetrating the tube plate, and a first chamber, which is a compressed air inlet, and a compressed air outlet, are installed in the first header. A second chamber which is a discharge air outlet, a third chamber which is a discharge air outlet, a fourth chamber which is a cooling fluid inlet, and a fifth chamber which is a cooling fluid outlet are communicated with the second header via a check valve. The 6th and 7th rooms are established, with the Moeki pre-cooler section in the 1st and 6th rooms, the air blower coolers in the 6th and 3rd rooms, and the after-coolers in the 2nd and 7th rooms. The fluid circulation space is formed to communicate with the fourth chamber and the fifth chamber through through holes provided in the tube plate, respectively.

Therefore, installation and piping space are reduced, and the compressor unit can be made more compact.

Furthermore, by simplifying the piping by reducing the length of the piping, reducing the number of piping connections, and centralizing the piping, it is possible to reduce the number of parts and improve workability during manufacturing and maintenance and inspection.

Furthermore, vibrations, thermal expansion, etc. of the air cooler body do not affect the piping, and loosening and vibration of the piping can be prevented, and the inside of the air cooler can be removed without removing the piping. In other words, each cooler. Maintenance and inspection of the check valve becomes easier.

In addition, the check valve is connected to a drain generated from compressed air. In addition to being able to extend the lifespan without exposing it to high heat,
This has the effect of minimizing the amount of air being blown out.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an air cooler according to the present invention, FIG. 2 is a right side view of the device shown in FIG. 1, and FIG. 3 shows only the bottom surface of the first header of the device shown in FIG. Figure 4 is a cross-sectional view taken along line I-[ of Figure 1, Figure 5 is a cross-sectional view taken along line ■-n of Figure 1, and Figure 6 is a screw air compressor to which the air cooler according to the present invention is applied. Figure 7 is an air and cooling water system diagram of a screw air compressor using a conventional air cooler. I1... Air cooler, ■2... Fuselage, 13, 13a
... Tube sheet, l4... First header, l5... Second header, l6... Heat exchanger tube group, +6a... Pre-turner section, +6b... After cooler section, 16c... Radiation Kaze Kuraro, 17...1st house, l...2nd house, 19...
・3rd room, 20...4th room, 21...5th room, 28
...Check valve, 30...6th chamber, 31...7th chamber,
32...first through hole, 33...second through hole.

Claims (1)

[Claims] (1) First and second headers are installed on both sides of a body whose ends are closed with tube plates, and the fluid circulation space inside the body is divided into a pre-cooler section, an after-cooler section, and an air cooler section. A heat transfer tube group consisting of a plurality of tubes is provided to penetrate the tube sheet, and the first header has a first chamber as a compressed air inlet, a second chamber as a compressed air outlet, and a left air outlet. a third chamber, a fourth chamber serving as a cooling fluid inlet;
A fifth chamber, which is a cooling fluid outlet, is provided with a sixth chamber and a seventh chamber communicating with the second header via a check valve, and the pre-cooler section is connected to the first chamber and the sixth chamber, and an air discharge cooler section is provided. to the sixth and third chambers, the aftercooler part to the second and seventh chambers, and the fluid circulation space to the fourth and fifth chambers through through holes provided in the tube plate, respectively. An air cooler for an oil-free screw air compressor characterized by being formed in communication with each other.