Blow-off valve for turbo blower

A blow-off valve for a turbo blower 1000 has a body part 100 which includes a cylinder part 110, a valve-guide plate 130 on the cylinder part 110 and a head part 150 covering the valve-guide plate 130. In the cylinder part 110, a blow-connection opening 1038 connected with a blow opening 2500 of the turbo blower 2000 and a blow-off opening 1058 to blow off the emission air from the turbo blower 2000. A spool valve 300 is provided and a blow-pressure spool 380 is located at space connected with the blow-connection opening 1038 and a blow-pressure opposing spool 330 is located between the valve-guide plate 130 and the head part 150 and a stem of the spool valve penetrates the valve-guide plate 130 and is supported thereby. A three-way solenoid valve 20 is mounted on the head part 150.

FIELD OF THE INVENTION

The present invention relates to a blow-off valve for a turbo blower and, more particularly, to the blow-off valve for the turbo blower which blows off emission air to the atmosphere at early operation stage of the turbo blower.

BACKGROUND

The turbo blower is a machine which revolves an impeller at high speed by means of a motor to draw external air and blow it. The turbo compressor is the same machine as the turbo blower, however, the term of the turbo compressor is used when the discharging pressure is high. If the pressure is less than 1 bar we usually call it turbo blower and if the pressure is over 1 bar we usually call it turbo compressor.

The turbo blower is generally used for pneumatic conveying or aeration at a sewage disposal plant so on and the turbo compressor is used for pneumatic conveying or supplying pressurized air to pneumatic equipment and so on.

In the present invention, the term of the turbo blower includes the turbo compressor.

The pressure of the emission air is low at early stage of operation of the turbo blower since the motor does not reach the steady state and it is difficult to use the air. For example, the emission air pressure at the early stage is too low to use for the aeration. Accordingly, the air is blown off to the atmosphere until the motor reaches the steady state. After the motor reaches the steady state, the air is emitted to the originally-intended place.

For this purpose, conventionally, a butterfly valve has been used, which requires a compressor and an actuator. The compressor generates high pressure air to operate the actuator for the butterfly valve. The actuator operates the butterfly valve to blow off the air at the early stage of the turbo blower and emit the air to the originally-intended place after the turbo blower reaches the steady state.

However, in this case, electricity rates are wasted for the operation of the compressor. Further, the compressor may cause a problem, which leads to the problem of the turbo blower. Furthermore, tube connecting the compressor and the butterfly valve occupy space, the length of the tube may be the problem and installation of a separated power source is required for the operation of the compressor, all which causes complication. Therefore, it is desirable if the blow-off the air is performed without the compressor. The present invention satisfies this demand.

DISCLOSURE

Technical Problem

The purpose of the present invention is to provide a blow-off valve which can blow off the air to the atmosphere at the early stage of the turbo blower without the compressor.

Technical Solution

The present invention provides a blow-off valve for a turbo blower comprising: a body part including a blow-connection opening connected with a blow opening of a turbo blower and a blow-off opening through which air emitted from the turbo blower through the blow-connection opening is blown off; a spool valve provided in the inner part of the body part having a blow-pressure spool located at a blow-pressure supply space formed in the inner part of the body part and connected with the blow-connection opening and a blow-pressure opposing spool located at a blow-pressure opposing space formed in the opposite space to the blow-pressure supply space; wherein pressure applying area of the blow-pressure spool is smaller than that of the blow-pressure opposing spool and the blow-off opening is formed between the blow-pressure spool and the blow-pressure opposing spool of the spool valve; and a three-way valve provided in the body part having a port connected with the blow-pressure supply space, a port connected with the blow-pressure opposing space and a port connected with an external atmosphere, the three-way valve shutting off the port connected with the blow-pressure supply space to connect the blow-pressure opposing space and the external atmosphere at early operation stage of the turbo blower and shutting off the off the port connected with the external atmosphere to connect the blow-pressure supply space and the blow-pressure opposing space.

In this case, it is desirable if the blow-pressure opposing spool is formed by a diaphragm.

In this case, it is desirable if the three-way valve is a three-way solenoid valve.

In this case, it is desirable if the body part has a cylinder part and a valve-guide plate through which a stem of the spool valve penetrate and is supported, the valve-guide plate mounted on the cylinder part, and a head part mounted on the valve-guide plate for covering the valve-guide plate; and the blow-pressure spool is located at the cylinder part and the blow-pressure opposing spool is located between the vale-guide plate and the head part.

In this case, it is desirable if an atmosphere connection opening is formed on the side of the valve-guide plate to communicate with the external atmosphere.

In this case, it is desirable if cross section of the valve-guide plate is nearly U-shape and the internal space of the upper portion of the valve-guide plate becomes larger.

In this case, it is desirable if the three-way valve is mounted on the head part and a ring is mounted on lower surface of the head part, an area formed inside the ring being larger than the pressure applying area of the blow-pressure spool.

Advantageous Effects

The present invention provides the blow-off valve which can blow off the emission air from the turbo blower by means of the emission air itself and without the compressor. Especially, the spool in the blow-pressure opposing space is formed by the diaphragm and the rapid response with the short stroke is assured.

MODE FOR INVENTION

FIG. 1shows an external appearance of a blow-off valve1000according to the embodiment of the present invention.

Firstly, the blow-off valve1000has a body part100. The body part100includes a cylinder part110and a valve-guide plate130on the cylinder part110and a head part150mounted on the valve-guide plate130.

It is preferable if the cross section of the valve-guide plate130is nearly U-shape and the internal space of the upper portion becomes larger.

According to the present invention, a blow-connection opening1038connected with a blow opening2500of the turbo blower2000is formed on the body part100.

Further, a blow-off opening1058through which the emitting air from the blow-connection opening1038is blown off is formed on the body part100.

In the embodiment, the blow-connection opening1038and the blow-off opening1058are all formed on the cylinder part110and, especially, the blow-connection opening1038is formed on the bottom of the cylinder part110and the blow-off opening1058is formed on the side of the cylinder part110with reference toFIG. 1.

According to the embodiment, flanges103and105are formed around the blow-connection opening1038and the blow-off opening1058, respectively and they are connected with flanges2053and1805around the blow opening2500of the turbo blower2000and a silencer1800, respectively. (Refer toFIG. 6)

Accordingly, the emitting air emitted through the blow opening2500of the turbo blower2000flows into the body part100through the blow-connection opening1038, and then is blown off through the blow-off opening1058to the external atmosphere after the suppression of noise by means of the silencer1800.

According to the present invention, a three-way valve20is provided in the body part100to connect blow-pressure supply space51, blow-pressure opposing space S2and the external atmosphere external to the body part100. In this embodiment, solenoid valve is provided as the three-way valve20and the solenoid valve20is mounted on the head part150of the body part100.

As described later, in the solenoid valve20, a port22is connected to the blow-pressure supply space51through a tube8and a port24is connected to the blow-pressure opposing space S2by perforating the head part150, and an air vent28is connected to the external atmosphere.

FIGS. 2 to 5show the internal structure of the blow-off valve1000according to the embodiment of the present invention. Specifically,FIG. 2shows an exploded view of the blow-off valve1000,FIG. 3shows a front sectional view of the blow-off valve1000,FIG. 4shows a side sectional view of the blow-off valve1000andFIG. 5shows a partially broken away perspective view of the blow-off valve1000.

As shown, the blow-connection opening1038is formed on the bottom of the cylinder part110.

A support ring200is provided in the inner part of the cylinder part110and the valve-guide plate130is mounted on the cylinder part110. As shown, an opening is formed on the center of the valve-guide plate130and a guide part1350in which a hollow portion1358is formed is provided in the opening on the center of the valve-guide plate130.

According to the present invention, a disk valve300is provided in the inner part of the body part100. In this embodiment, in the disk valve300, a disk380is located on the support ring200in the inner part of the cylinder part110and an opposite disk330is located in the space formed by the valve-guide plate130and the head part150. A stem350connecting the disks380and330is placed through the hollow portion1358of the guide part1350in the valve-guide plate130. At this time, bushings214are arranged at the hollow portion1358of the guide part1350in the valve-guide plate130.

In this case, an internal space of the cylinder part110between the disk380and the blow-connection opening1038forms blow-pressure supply space51. An internal space between the head part150and the disk330in the inner part of the body part100forms the blow-pressure opposing space S2and the pressure which opposes the pressure in the blow-pressure supply space51is formed therein.

According to the present invention, the disk330may include a diaphragm333and a plate335contacting the lower surface of the diaphragm333.

In this case, the circumferential part of diaphragm333is placed between the contacting surfaces of the head part150and the valve-guide plate130and the disk330is mounted.

As described, the disk330is formed by the diaphragm333so that the disk valve300can move with a short stroke and the response is very rapid.

In this embodiment, a spring211is mounted on the on the stem350below the plate335in the space between the valve-guide plate130and the head part150. Accordingly, more rapid response of the disk valve300is assured.

According to the embodiment, the disk380is located in the inner part of the cylinder part110and the disk330is located in the inner part of the valve-guide plate130and is in contact with the inner surface thereof. In the valve-guide plate130, the cross section is nearly U shape and the internal space of the upper portion becomes larger. Accordingly, pressure applying area of the disk330which is in contact with the inner surface of the valve-guide plate130is larger than that of the disk380.

In this embodiment, the blow-off opening1058is formed between the disks330and380on the side of the cylinder part110of the body part100.

According to the present invention, the three-way valve20is provided in the body part100to connect the blow-pressure supply space51, the blow-pressure opposing space S2and the external atmosphere.

In this embodiment, the solenoid valve mounted on the head part150of the body part100is provided as the three-way valve20. The port22of the solenoid valve20is connected to the blow-pressure supply space51through the tube8and the port24of the solenoid valve20is connected to the blow-pressure opposing space S2by perforating the head part150, and the air vent28of the solenoid valve20is connected to the external atmosphere.

To connect the tube8with the blow-pressure supply space51in the cylinder part110of the body part100, as shown, through holes218and118are formed on the support ring200and the cylinder part110, respectively and a fitting member of the tube8is fitted through the through holes218and118.

Further, an atmosphere connection opening138is formed on the side of the valve-guide plate130to communicate with the external atmosphere.

The operation of the blow-off valve1000having the described structure is, now, explained.

At the early operation stage of the turbo blower2000, if the revolution power of the motor is weak and there is a need to blow off the emission air from the turbo blower2000, the solenoid valve20shuts off the port22in connection with the blow-pressure supply space51and makes the blow-pressure opposing space S2communicate with the external atmosphere.

At this state, the emission air from the turbo blower2000flows into the blow-pressure supply space51through the blow-connection opening1038.

At this time, whereas the pressure in the blow-pressure opposing space S2is at the external atmosphere pressure, the blow-pressure supply space51is at the emission pressure from the turbo blower2000so that the disk380of the disk valve300moves and the blow-connection opening1038and the blow-off opening1058are connected. As a result, the emission air is blown off through the blow-off opening1058.

Then, if the operation of the turbo blower reaches the steady state, the solenoid valve20shuts off the port28to the external atmosphere and connects the blow-pressure supply space S1and blow-pressure opposing space S2.

In this case, the pressure in the blow-pressure opposing space S2becomes almost same as the pressure in the blow-pressure supply space51.

Since the pressure applying area of the disk330is larger than that of the disk380so that the disk valve300moves to close the disk380. Accordingly, the emission air in the blow-pressure supply space51from the turbo blower2000is no longer blown off and is sent to blow opening2500.

In this case, since the air between the disk330and the valve-guide plate130is communicated with the external atmosphere through the atmosphere connection opening138, the disk330rapidly moves to close the bottom disk380.

At this time, the disk330is formed by the diaphragm333and the rapid response with the short stroke is assured, as described. If a sealing member is provided for preventing leakage between the disk380and the support ring200below the disk380, it is preferable.

In this embodiment, on the lower surface of the head part150, a ring158is mounted to guarantee minimum pressure applying area for the disk330.

If the ring is not provided, when the disk330contacts the lower surface of the head part150, the pressure applying area may become the area corresponding to the port24of the solenoid valve20and the pressure applying area in the blow-pressure opposing space S2may be smaller than that in the blow-pressure supply area51, which leads to malfunction of the blow-off valve1000.

The ring158prevents the malfunction. The area formed inside the ring should be larger than the pressure applying area of the disk380.

As described above, the present invention provides the blow-off valve which can blow off the emission air from the turbo blower by means of the emission air itself and without the compressor. Especially, the disk330in the blow-pressure opposing space S2is formed by the diaphragm333and the rapid response with the short stroke is assured.

Therefore, it is understood that the purpose of the present invention is accomplished.

The present invention is described with reference to the specific embodiments, but the invention is not limited thereto. Only the following claims will determine the scope of the invention.