JPH045918B2 - - Google Patents

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), the high-temperature, high-pressure compressed air discharged from the compressor body is cooled before being sent to the consumption point via a check valve. 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, in the case of an oil-free compressor that compresses up to 7.0 kg/cm ² G in one stage and has a discharge temperature of 350°C or higher, a check valve (heat-resistant temperature 200~
250°C) in an atmosphere at this discharge temperature, the valve body and spring will no longer perform their function after repeated use. 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-cooler 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 loading operation, the compressed air is led to an aftercooler for further cooling before being 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. be.

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 provided separately and independently on the discharge side of the compressor main body 1. Then, the compressed air discharged from the compressor main body 1, for example, 7.0 kg/cm ² G, 350°C compressed air, is primarily cooled to 150 to 200°C in the precooler 2, and then passed through the check valve 3 to the aftercooler 4. at 45℃
It is designed to be cooled down to a temperature of 100% and then pumped to a consumption point (not shown). In addition, an air release line is provided that branches between the compressor main body 1 and the precooler 2 and opens to the atmosphere via an air release cooler section 2a in the precooler 2 and an air release valve 5.
The compressed air that has been primarily cooled in the air cooler section 2a inside is blown into the atmosphere. Note that 6 is a safety valve and 7 is an intake valve.

(Problems to be Solved by the Invention) In the conventional device, the pre-cooler 2 and the after-cooler 4 are provided separately and independently. For this reason,
This equipment requires air piping and cooling water piping between both coolers, which not only complicates the piping, but also increases the piping space within the equipment, making the equipment bulky and requiring a large installation space. There is a problem.

On the other hand, it is conceivable to form the precooler 2, check valve 3, and aftercooler 4 in the same casing. 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 if a large number of tubes are installed in parallel, it only has one pass. Although there is a possibility of applying cooler 4 to improve the heat exchange rate,
It includes three devices, a pre-cooler 2, a check valve 3, and an after-cooler 4, each of which performs a different function.
There is a problem in that it cannot be applied to a line on the discharge side of a compressor that has multiple passes (a pass to a consumption point and a pass for blowing air).

In other words, the devices described in the above-mentioned publications differ only in the arrangement of the meandering flow path, that is, the plurality of pipes constituting one pass. There is basically no difference from the pre-cooler 2 and the after-cooler 4, which are independent coolers when omitted, and both are simply provided with one type of path within the same casing. Therefore, it cannot be applied to the above-mentioned compressor which requires branching of the discharge side line, multiple types of paths, and check valves.

The present invention has been made to address these conventional problems, and by housing the discharge side line including the pre-cooler, after-cooler, and blow-off cooler in the same casing, the functions of each part of the device are not impaired. The present invention aims to provide an air cooler for an oil-free compressor that has a structure that simplifies piping, reduces installation space, and requires less time and effort for manufacturing and maintenance.

(Means for Solving the Problems) In order to solve the above problems, the present invention includes first and second headers attached to both sides of a body whose ends are closed with tube sheets, and a precooler installed in a fluid circulation space inside the body. A group of heat transfer tubes consisting of a plurality of tubes arranged in separate areas in the section, aftercooler section, and air cooler section is provided to penetrate the tube plate, and a first chamber, which is a compressed air inlet, is provided in the first header. , a second chamber that is a compressed air outlet, 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 through a check valve, and the precooler section is connected to the first chamber. and the air cooler part in the 6th room and the 3rd room.
The aftercooler section was formed in the chamber to communicate with the second chamber and the seventh chamber, and the fluid circulation space was formed in communication with the fourth chamber and the fifth chamber through through holes provided in the tube plate, respectively.

(Function) By forming as above, the precooler,
The check valve, aftercooler, and air blower cooler are housed in the same casing, greatly simplifying piping, reducing installation space, and reducing labor during manufacturing and maintenance inspections.

Furthermore, since a check valve is provided at the outlet of the pre-cooler section, the amount of air blown during air blowing is minimized and corrosion of the check valve 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, an example of the present invention will be described with reference to the drawings.

1 to 5 show an air cooler 11 for an oil-free compressor according to the present invention, in which both ends of a body 12 are closed with tube sheets 13, 13a, and a A second header 15 is removably attached to the left side of the first header 14 and the tube plate 13a.
Inside the body 12 is a heat exchanger tube group 1 consisting of a plurality of tubes.
6 are arranged in parallel, passing through the tube plates 13 and 13a.

Note that, as shown in FIG.
It is slidably fitted into the end of 2 through a sealing means S.

The first header 14 has a first chamber 17, a second chamber 18, a third chamber 19, a fourth chamber 20, and a fifth chamber 21 inside, as shown in FIG. ，
23, 24, 25, and 26, and the second chamber 18 is further provided with a safety valve mounting seat 27. Note that the nozzle head 22 and the nozzle head 25 are a common nozzle head as shown in FIG.

Inside the second header 15, as shown in FIG. A sixth chamber 30 is formed inside, and a seventh chamber 31 is formed outside.

As shown in FIGS. 4 and 5, the heat exchanger tube group 16 includes a pre-cooler section 16a and an after-cooler section 16.
b and an air blowing cooler section 16c.
In FIG. 5, in order to clearly show these parts, the heat exchanger tubes forming each part are connected with solid lines.
Then, the pre-cooler section 16a is attached to the first header 1.
4 and the sixth chamber 3 of the second header 15.
0, the aftercooler section 16b communicates with the second chamber 18 and the seventh chamber 31, and the air discharge cooler section 16c communicates with the third chamber 19 and the sixth chamber 30, respectively.

As shown in FIG. 5, the tube sheet 13 is provided with a first through hole 32 below the pre-cooler section 16a and a second through hole 33 above the after-cooler section 16b. 4th room 20,
It communicates with the fifth chamber 21.

Inside the body 12, as shown in FIG. 1, a plurality of baffle plates 34 are arranged at appropriate intervals in the longitudinal direction of the heat exchanger tube group 16, and arranged in parallel. The water return pipe 35 is connected to the second through hole 3 of the tube sheet 13.
3 to the final baffle plate 34a closest to the tube plate 13a, and is formed so as to guide the cooling water on the tube plate 13a side to the fifth chamber 21.

The air cooler 11 having the above configuration is functionally homogeneous and is not simply an integrated unit of a pre-cooler (meaning one that does not include a blow-off cooler section) and an after-cooler located on one path. In contrast, the air discharge cooler section 16c branched from the line on the aftercooler section 16b side, and the discharge side part of the compressor, including the check valve 28, which has a completely different function from cooling, can be housed in the same casing without impairing the functions of each part. It is housed in and integrated into one. Specifically, as mentioned above, compressed air at, for example, 350°C is primarily cooled to 150 to 200°C in the pre-cooler section 16a, cooled to about 45°C in the after-cooler section 16b, and then
The pre-cooler section 16a is pumped to the consumption point.
In this case, the compressed air is in a temperature range where no condensate is generated and the check valve 28 is not damaged by heat, and the aftercooler section 16b is in a temperature range where condensate is generated. In the case of this device, the check valve 28 is installed on the side of the precooler section 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 28, even when the compressor is unloaded, the compressed air is primarily cooled in the pre-cooler section 16a while reliably preventing backflow of the compressed air from the after-cooler 16b side. The compressed air is further cooled in the air blowing cooler section 16c and blowing air is performed. Further, as mentioned 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 at the inlet of the pre-cooler section 16a.
By providing this, the amount of air discharged is reduced. On the other hand, if the check valve 28 is installed at a different position, for example on the aftercooler section 16b side, the compressed air inside the second header 15 will also be blown out, and the volume inside this second header 15 will be cannot be made too small in order to ensure a smooth flow of the discharged compressed air, so the amount of air discharged becomes large. As mentioned above, by housing the pre-cooler section 16a etc. in the same casing and integrating them, piping between each cooler and the check valve becomes unnecessary, which reduces the troublesome work during manufacturing and maintenance inspection. , the installation space is becoming smaller. Further, in this air cooler 11, all nozzles are concentrated in one first header 14 to form a common header. In other words, simply integrating the pre-cooler and after-cooler will not solve the problems described in U.S. Pat.
As in the heat exchanger described in the above publication, the connection parts with external piping are scattered over the entire circumference. Further, a nozzle holder is provided in the body 12, and fluid enters and exits through an external pipe connected to the nozzle holder. On the other hand, in the air cooler 11, not only the compressed air but also the cooling water are connected to the external piping, that is, all the nozzles are concentrated in the first header 14.
For example, the first through hole 32 and the water return pipe 3 are provided in the tube plate 13.
5 is provided, and the first through hole 33 is provided.
By forming a fourth chamber 30 and a fifth chamber 21 in the header 14 that communicate with these through holes, respectively,
Fluid can flow in and out of the body 12 by simply connecting external piping to the nozzles 25 and 26 provided in the first header 14. Therefore, air cooler 1
The piping to 1 is in one place, that is, the first header 14
This simplifies piping. In addition, the tube plate 13a, which is one fixed part of each cooler part, is completely independent from the connection point with the external piping and is provided so as to be able to slide freely, so that the tube plate 13a is a fixed part of each cooler part. Since it is designed to be able to respond freely, 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 cooler section of the air cooler 11 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, in which parts common to FIGS. 1 to 5 are given the same numbers, and the first chamber 17 is a discharge line b from the compressor main body 1, a second chamber 18 is a supply line c leading to a consumption point (not shown), a third chamber 19 is an air discharge line d having an air discharge valve 5, a fourth chamber 20 and a fifth chamber Cooling lines e and e' are connected to the chambers 21, respectively.

The safety valve 6 is connected to a nozzle 27 provided in the second chamber 18.
However, in FIG. 6, it is shown on the supply line c for convenience to avoid complicating the drawing.

The cooling water that has flowed into the fourth chamber 20 flows into the body 12 , 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 and flows into the first chamber 17 of the air cooler 11 through the discharge line b. Pre-cooler section 16a
It flows into the seventh chamber 31 from the sixth chamber 30 via the check valve 28, and is cooled in the aftercooler section 16b.
After being further cooled, it is sent from the second chamber 18 to the point of consumption through the supply line c.

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 section 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, the first and second
A header is attached, and a heat transfer tube group consisting of a plurality of tubes arranged in a pre-cooler section, an after-cooler section, and a ventilation cooler section in the fluid circulation space inside the body is provided by penetrating the tube sheet;
a first chamber serving as a compressed air inlet to the first header;
The second chamber is a compressed air outlet, the third chamber is a discharge air outlet, the fourth chamber is a cooling fluid inlet, the fifth chamber is a cooling fluid outlet, and a check valve is installed in the second header. A sixth chamber and a seventh chamber are provided which communicate with each other through the pre-cooler section, the air cooler section between the first chamber and the sixth chamber, the air cooler section between the sixth chamber and the third chamber, and the after-cooler section between the second chamber and the third chamber. The fluid circulation space is formed to communicate with the seventh chamber and the fourth chamber and the fifth chamber through through holes respectively provided in the tube plate.

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, the vibrations, thermal expansion, etc. of the air cooler body do not affect the piping, and it is possible to prevent the piping from loosening and vibration. Maintenance and inspection become easier.

Furthermore, it is possible to prolong the life of the check valve without exposing it to condensate generated from compressed air and high heat, and it also has the effect of minimizing the amount of air blown.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an air cooler according to the present invention;
2 is a right side view of the device shown in FIG. 1, FIG. 3 is a view showing only the bottom of the first header of the device shown in FIG. 1, and FIG. Figure 5 is a sectional view taken along the - line in Figure 1, Figure 6 is an air and cooling water system diagram of a screw air compressor to which the air cooler according to the present invention is applied, and Figure 7 is a diagram of a system using a conventional air cooler. It is an air and cooling water system diagram of the screw air compressor. 11... Air cooler, 12... Fuselage, 13,1
3a... Tube sheet, 14... First header, 15... Second header, 16... Heat exchanger tube group, 16a... Pre-cooler section, 16b... After-cooler section, 16c...
...Air cooler part, 17...1st room, 18...2nd room
Room, 19...3rd room, 20...4th room, 21...
Fifth chamber, 28... Check valve, 30... Sixth chamber, 31
...7th chamber, 32...1st through hole, 33...2nd
Through hole.

Claims (1)

[Claims] 1 The first and second
A header is attached, and a heat transfer tube group consisting of a plurality of tubes arranged in a pre-cooler section, an after-cooler section, and a ventilation cooler section in the fluid circulation space inside the body is provided by penetrating the tube sheet;
a first chamber serving as a compressed air inlet to the first header;
The second chamber is a compressed air outlet, the third chamber is a discharge air outlet, the fourth chamber is a cooling fluid inlet, the fifth chamber is a cooling fluid outlet, and a check valve is installed in the second header. A sixth chamber and a seventh chamber are provided, which communicate with each other through the pre-cooler section, the air cooler section between the first chamber and the sixth chamber, the air cooler section between the sixth chamber and the third chamber, and the after-cooler section between the second chamber and the third chamber. An oil-free screw air compressor, characterized in that the air is connected to the seventh chamber, and the fluid circulation space is connected to the fourth chamber and the fifth chamber through through holes provided in the tube plate. Cooler.