JPH0858885A - Ventilator for powder-storage tank - Google Patents

Abstract

PURPOSE: To replace the air inside a powder-storage tank with outside air so as to prevent condensation of moisture and so forth by providing at least two air, intake-discharge units each having a filter unit and a fan unit and a switchover valve between intake and discharge in each of the fan wits. CONSTITUTION: There are provided in a ventilator at least two air intake discharge units 12 each having a filter unit 16 and a fan unit 16. The filter unit 14 is placed above a powder-storage tank 38 for storing powder fed in through a powder-feeding port 40 and separates air from the powder. The fan unit 16 discharges the separated air to the outside and also takes in outside air and feeds it through the filter unit 14. In each of the fan units 16 there are provided a two-way suction-side switchover valve 30 and a discharge-side switchover valve 32: the valve 30 switches over a fan 24 and its suction port 26 either to a suction-discharge port 22 of the filter unit 14 or to the outside air; the valve 32 switches over the discharge port 28 of the fan 24 likewise to either of the two ways.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ventilation system for a powder storage tank. The present invention relates to a powder storage tank ventilation device capable of controlling temperature and humidity.

[0002]

2. Description of the Related Art In recent years, like powders such as cement, cereals such as wheat flour have been widely distributed such as transported and stored in bulk without being packed in bags. In response to the situation, the powder storage tanks at mills are also becoming larger. The powder is put into this large-sized powder storage tank by directly connecting its end to the powder storage tank by using pneumatic transportation. In addition, such pneumatic transportation of powder is a method often used for feeding powder from a tank of a powder transport vehicle to a powder storage tank of a user such as a bread making and noodle making factory.

The air used for the above-mentioned pneumatic transportation needs to be separated in the powder storage tank and discharged to the outside of the powder storage tank. For this reason, an exhaust pipe for the internal air of the powder storage tank is installed separately from the powder loading pipe in the powder storage tank, and a bag filter dedicated to exhaust is installed in the exhaust pipe. The air inside the powder storage tank is exhausted via the. As the filter described above, a filter having a pulse jet type backwashing mechanism is preferable because the bag filter can be cleaned even during powder transportation. However, a mechanical vibration type may be used, and the powder adhered to the dust can be sufficiently removed after the powder transportation is completed. This method is often used for the above-mentioned user's powder storage tank.

Even in the storage tanks for powder products in the mill,
Although such direct feeding by air transportation is often performed, in the case of a flour mill, there are problems as described below. That is, the temperature of the wheat flour immediately after being milled in the mill is slightly higher than that of the surroundings, specifically, about 5 to 8 ° C., due to pulverization and other treatments. Therefore, if this powder is directly put into the powder storage tank, there occurs a problem that a dew condensation phenomenon occurs on the wall or ceiling of the space above the powder storage tank during storage.

For this reason, a suction pipe is connected to the powder storage tank into which the powder immediately after being milled is introduced, and the air inside the powder storage tank is sucked and exhausted to the outside of the powder storage tank. The air outside the powder storage tank is introduced into the interior of the. That is, the air inside the powder storage tank is ventilated. In addition, the upper ceiling or wall of the powder storage tank, which is a space, may be heat-insulated with a heat insulating material or may be heated with a heating wire in order to block heat from the outside of the powder storage tank.

However, since such heat retention and halfway ventilation are not sufficient as measures against dew condensation, it is necessary to provide a more active ventilation device. It is considered to install a ventilation fan and piping for that purpose. When ventilating the internal air of the powder storage tank,
If the exhaust side of the ventilation fan is connected to the powder storage tank, that is, if external air is forced into the powder storage tank by the ventilation fan, powder may blow out from the powder storage tank and pollute the surroundings. Therefore, connect the intake side of the ventilation fan to the powder storage tank, that is, forcibly suck the internal air of the powder storage tank by the ventilation fan and force the internal air of the powder storage tank. It is being discharged. However, at this time, if the pipe on the intake side is thin, or if this pipe is clogged with powder, especially in the case of a steel powder storage tank,
There is also a problem that the powder storage tank may be damaged due to negative pressure inside the powder storage tank.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to solve various problems based on the above-mentioned prior art and replace the internal air of the powder storage tank with the external air to prevent dew condensation in the powder storage tank. In order to equalize the internal pressure and the external pressure of the powder storage tank by equalizing the intake air amount and the exhaust air amount when ventilating the internal air of the powder storage tank, It is an object of the present invention to provide a ventilation apparatus for a powder storage tank, which can be realized by switching intake and exhaust air to and from the intake and exhaust unit with a two-way switching valve in order to prevent damage to the storage tank.

[0008]

In order to achieve the above object, the present invention is provided at the upper part of a powder storage tank for storing powder charged from a powder charging port, and separates powder from air. And a fan unit capable of exhausting the air separated by the filter unit to the outside and introducing the outside air into the filter unit. Is a fan, an intake side two-way switching valve that switches the intake port of the fan to either the intake port or the exhaust port of the filter unit or the external air, and the exhaust port of the fan to the intake port or the external port of the filter unit. The present invention provides a ventilation device for a powder storage tank, which has an exhaust side two-way switching valve that switches to either one of air.

Here, it is preferable that the intake / exhaust unit further includes a silencer arranged between the fan unit and the external air of the powder storage tank. Further, it is preferable that the filter unit further has a backwashing mechanism for the filter. Further, the backwashing mechanism of the filter is preferably a mechanism for ejecting a pulse jet to the filter from the side of separated air. The two-way switching valve of the fan unit preferably has an automatic drive mechanism.

[0010]

The ventilation device for a powder storage tank according to the present invention comprises a filter unit for separating air-transported powder from air.
By appropriately installing the two 2-way switching valves, either the internal air of the powder storage tank or the external air of the powder storage tank is sucked through the filter unit, and the air is supplied to either the inside or the outside of the powder storage tank. At least two intake / exhaust units each having a fan unit capable of exhausting air are provided, and at the time of powder introduction, in each intake / exhaust unit, two two-way switching valves are switched so that the intake port of the fan and Connect the exhaust port to the intake and exhaust ports of the filter unit and the external air, and when replacing the air after the powder is charged, in one of the intake and exhaust units, set the fan intake port and exhaust port to the intake and exhaust ports of the filter unit and the external air, respectively. In the other intake / exhaust unit, the intake and exhaust ports of the fan are connected to the external air and the filter unit, respectively. It can communicate with the other outlet of bets.

Further, the intake side two-way switching valve and the exhaust side two-way switching valve of this intake / exhaust unit are set so that the air inside the powder storage tank is exhausted to the outside of the powder storage tank in all of the intake / exhaust units. Thus, when the powder mixed air is introduced into the powder storage tank by pneumatic transportation, only the air carrying the powder can be exhausted to the outside of the powder storage tank via the filters of the two intake / exhaust units. .

At least one intake / exhaust unit sucks the air outside the powder storage tank into the powder storage tank, and at least another intake / exhaust unit transfers the internal air from the powder storage tank to the outside of the powder storage tank. By setting the intake side two-way switching valve and the exhaust side two-way switching valve of the at least two intake / exhaust units so as to exhaust, at least 1 is set after the powder mixed air is completely introduced into the powder storage tank by pneumatic transportation. The outside air of the powder storage tank is sucked into the inside of the powder storage tank through the filter of one intake / exhaust unit, and at the same time, only the air inside the powder storage tank is powdered through the filter of at least one other intake / exhaust unit. The air inside the powder storage tank can be efficiently ventilated by exhausting to the outside of the body storage tank, and the internal temperature of the powder storage tank can be adjusted. The inside of the powder storage tank becomes a negative pressure by balancing the amount of intake air to the powder storage tank by at least one intake / exhaust unit and the amount of exhaust air from the powder storage tank by at least one other intake mechanism. It is possible to prevent the powder storage tank from being damaged.

Further, the intake side two-way switching valve and the exhaust side two-way switching valve of this intake / exhaust unit are set so that the air outside the powder storage tank is sucked into the powder storage tank in all the intake / exhaust units. Thus, the powder adhering to the filters of at least two intake / exhaust units can be backwashed and cleaned. At this time, as an exhaust path for the external air of the powder storage tank sucked by the intake / exhaust unit,
For example, it is preferable to separately provide an exhaust port in the powder storage tank.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The ventilation device for a powder storage tank according to the present invention will now be described in detail with reference to the preferred embodiments shown in the accompanying drawings.

As shown in FIG. 1, the powder storage tank ventilation device 10 of the present invention includes two intake / exhaust units 12 having the same structure.
(12a, 12b), the intake and exhaust unit 12
Is usually used by being disposed above the powder storage tank 38 that stores the powder that is input from the powder input port 40, and the powder and air after air transportation inside the powder storage tank 38 are used. The filter unit 14 to be separated and the air separated by the filter unit 14 are exhausted to the outside of the powder storage tank 38, or the air outside the powder storage tank 38 is filtered by the filter unit 1.
The fan unit 16 that supplies the powder to the inside of the powder storage tank 38 via the No. 4 and the silencer 34 for silencing.

Here, the filter unit 14 includes a filter 18 for separating powder and internal air, and the filter 1
Filter housing 20 for housing 8 and filter 18
The filter housing 20 communicates with the powder storage tank 38 in the lower part of the figure, and similarly, the filter housing 20 in the upper part of the figure has a suction port for connecting to the fan unit 16. It has an exhaust port. The fan unit 16 is provided with a fan 24 having an intake port 26 and an exhaust port 28, and an intake port 26 of the fan 24.
Intake-side two-way switching valve 3 that switches the external air taken in via the silencer 34 and the internal air of the powder storage tank 38 taken in via the filter 18 and supplies it to the fan 24.
0, similarly, the air exhausted from the fan 24 is disposed at the intake port 26 of the fan 24 and is exhausted to the outside via the silencer 34, or the powder storage tank 3 via the filter 18.
Exhaust side two-way switching valve 3 that switches between exhausting inside 8
2 and.

Here, the filter 18 is a filter provided with a pulse jet type backwash mechanism, and is a tubular cloth filter having an oval cross section with one end 18a opened and the other end 18b closed, and the outside of the filter 18 Is a powder storage tank 38 (powder-
A plurality of filters 18 are arranged in the filter housing 20 such that the air mixture side and the open end 18a side of the filter 18 are the filtration (separation) air sides. Here, the shapes, dimensions, and materials of the filter 18 and the filter housing 20 are
It is not particularly limited, and known ones can be used,
It may be appropriately selected depending on the target powder, the powder storage tank 38, the fan 24, and the like. Although two filters 18 are shown in the filter housing 20 in the illustrated example,
Capacity of fan 24 (intake / exhaust volume and ventilation volume), powder storage tank 38
It may be appropriately selected depending on the size, shape, material, etc. of the filter 18.

The backwashing mechanism 36 of the filter 18 is a pulse jet type backwashing mechanism, and includes a nozzle 36a opening to the open end side of the filter 18 and high pressure air for generating pulse jets from a plurality of nozzles 36a. A supply pipe 36b for supplying the air, a solenoid valve 36c provided at an end of the supply pipe 36b for generating a pulse jet ejected from the nozzle 36a, and a collecting pipe 36d for supplying high-pressure air supplied to the plurality of solenoid valves 36c. , A high pressure air source (not shown). The pulse jet type backwash mechanism 36 turns on and off the electromagnetic valve 36c in a pulsed manner to eject a pulse jet from the nozzle 36a, and causes the filter 18 to open the open end 18 thereof.
The pulse jet is blown from a. The filter 18 sprayed with the pulse jet rapidly expands, and the high-pressure air that has become a jet is filtered by the filter 18
Is flowed back from the inside to the outside, the powder adhering to the outside is separated from the surface of the filter 18, and is dropped or scattered far from the surface of the filter 18. Thus, the filter 18 is backwashed by the pulse jet.

In the pulse jet type backwash mechanism 36, the powder separated from the surface of the filter 18 falls or flies far from the surface of the filter 18, so that even during the filtration operation by the filter 18, It does not immediately adhere to the filter 18 again. Therefore, the filter unit 14 having the pulse jet type backwash mechanism 36
Can backwash the filter 18 even during the filtering operation.

In the illustrated example, each filter unit 14 is provided so that the filter 18 of each filter unit 14 can be backwashed for each of the two intake and exhaust units 12a and 12b.
Each unit is provided with a pulse jet type backwash mechanism 36, but the present invention is not limited to this, and both units 12a and 1 are provided.
A backwash mechanism common to 2b may be used. When a large number of filters 18 are used, a plurality of supply pipes 3
It is better to use 6b. The number of nozzles 36a provided in one supply pipe 36b, the number of electromagnetic valves 36c (supply pipe 36b) connected to one collecting pipe 36d, etc. may be appropriately selected according to the number and arrangement of the filters 18, the backwash capability, and the like. Good.

The backwash mechanism 36 in the illustrated example is a pulse jet type backwash mechanism, but the present invention is not particularly limited to this, and a known backwash mechanism such as a mechanical vibration type backwash mechanism is used. Of course, you can. When using these known backwashing mechanisms, it is not preferable to perform backwashing during the filtration operation of the filter 18, and during the stoppage of the filtration operation,
Alternatively, it is preferable to perform backwashing during the backwashing operation (backwashing mode) of the filter 18, which will be described later.

Next, the fan 24 of the fan unit 16
Needs to have a required air volume and pressure, for example, a capacity of several m ³ / min and several tens to 200 mmAq, but a known fan may be used according to the required characteristics. Further, the intake side and exhaust side two-way switching valves 30 and 32 used for the intake port 26 side and the exhaust port 28 side of the fan 24 may be the same. The two-way switching valves 30 and 32 used here are valves that have openings on three sides and can be switched so that one opening communicates with either one of the remaining two openings. Any kind of valve may be used, and an on-off valve may be provided in each passage to open and close each other. 2 used here
The one-way switching valves 30 and 32 are preferably provided with an automatic drive mechanism. For example, switching of the valve communication direction is performed by an air cylinder (air actuator) or the like that is automatically driven by turning on / off a solenoid valve or the like. Is preferred.

One opening of the intake side two-way switching valve 30 is at the intake port 26 of the fan 24, and the two switching side openings of the intake side two-way switching valve 30 are the filtered air of the housing 20 of the filter unit 14. Installed on the side (upper side in the figure) (intake side)
The intake / exhaust port 22 and the opening (intake side) of the silencer 34 are connected directly or via an air pipe. Also,
The two switching-side openings of the exhaust side two-way switching valve 32 are connected to the exhaust port 28 of the fan 24 and the opening (exhaust side) of the silencer 34, and one opening of the two-way switching valve 32 is connected to the filter housing 20. It is connected to another provided (exhaust side) intake / exhaust port 22 directly or via an air pipe. The silencer 34 has two openings communicating with the outside air, and these openings are the opening connected to the intake side two-way switching valve 30 and the exhaust side opening connected to the two-way switching valve 32 of the silencer 34. It is in communication. The silencer 34 reduces the speed of the exhaust air (internal air) discharged to the outside to muffle the sound, and also reduces the intake speed even when the outside air is sucked from the outside, so that the silencer 34 uses a known silencer. You can

In the illustrated example, the filter unit 14
Intake / exhaust port 2 provided in the filter housing 20 of
The number of 2 is two, but the present invention is not limited to this and may be any number. The fan 2 used for the fan unit 16
The number of four is not limited to one in the illustrated example, and any number may be used, and the number of two-way switching valves 30 and 32 provided at the intake port 26 and the exhaust port 28 of the fan 24 is also arbitrary. May be. Further, the ventilation device 10 of the illustrated example has two identical intake / exhaust units 12, but the present invention is not limited to this, and the exhaust (filtration) operation (mode) and the ventilation operation (described later) will be described. Mode), backwash operation (mode), etc., as long as the pressure balance is not lost, any number may be used.

The ventilation device for a powder storage tank according to the present invention is basically constructed as described above. The operation will be described below by switching between the two two-way switching valves 30 and 32. The details will be mainly described.

In the powder storage tank ventilation device 10 of the present invention thus configured, the intake side two-way switching valve 30 and the exhaust side two-way switching valve 32 of the two intake / exhaust units 12 are appropriately switched. Thus, the following four combinations can be obtained. Note that other combinations do not make sense. Intake side two-way switching valve 30 Exhaust side two-way switching valve 32 Inhalation destination exhaust destination (a) Powder storage tank inside air → powder storage tank outside (one air intake / exhaust unit 12a setting) powder storage tank inside Air → Outside the powder storage tank (setting of the other intake / exhaust unit 12b) (b) Inside air of the powder storage tank → Outside of powder storage tank (the setting of one intake / exhaust unit 12a) External air of the powder storage tank → Powder Inside the body storage tank (setting of the other intake / exhaust unit 12b) (c) Outside air of the powder storage tank → Inside the powder storage tank (setting of one intake / exhaust unit 12a) Internal air of the powder storage tank → External (setting of the other intake / exhaust unit 12b) (d) External air of the powder storage tank → inside of the powder storage tank (setting of one intake / exhaust unit 12a) External air of the powder storage tank → Inside of the powder storage tank (other) Setting of intake / exhaust unit 12b)

Here, (a) can be referred to as an exhaust (filtering) operation mode, and in this mode, the internal air of the powder storage tank 38 is supplied to the powder storage tank 38 for both the two intake / exhaust units 12 (12a, 12b). It is exhausted to the outside. Also,
(b) and (c) can be referred to as a replacement operation mode. In this mode, in one of the intake / exhaust units 12 (12a or 12b), the internal air of the powder storage tank 38 is exhausted to the outside of the powder storage tank 38, And the other intake / exhaust unit 12
In (12a or 12b), the air outside the powder storage tank 38 is introduced into the powder storage tank 38. And (d) can be said to be a backwash operation mode, and in this mode, two intake / exhaust units 12 (12a, 12b)
In both cases, the air outside the powder storage tank 38 is sucked into the powder storage tank 38.

The four ventilation paths described above are shown in FIGS.
Further, a more specific description will be given with reference to the specific drawing shown in FIG. In the powder storage tank ventilation device 10 of the present invention shown in FIGS. 1 to 3, the one intake / exhaust unit 12 described above refers to the intake / exhaust unit 12a on the left side, and similarly, the other intake / exhaust unit 12 is used. The following description will be given assuming that the intake / exhaust unit 12a on the right side is shown. However, it is natural that the same operation can be performed even if it is reversed.

First, FIG. 1 is a schematic view showing one embodiment of the powder storage tank ventilation device 10 of the present invention when powder is charged. The powder storage tank ventilation device 10 shown in the same figure has two intake / exhaust units 1 included in the above-described powder storage tank ventilation device 10 of the present invention.
In the four combinations of the two intake side two-way switching valve 30 and the exhaust side two-way switching valve 32, the combination of (a) is set, and both the intake and exhaust units 12 are powdered by air transportation. At the same time, the air flowing into the powder storage tank 38 is exhausted to the outside of the powder storage tank 38 by the fan 24.

As described above, in the exhaust operation mode of the ventilation apparatus 10 for a powder storage tank of the present invention in which the intake side two-way switching valve 30 and the exhaust side two-way switching valve 32 are combined, the air-mixed powder is transported by air transportation. When the powder is introduced into the powder storage tank 38 through the powder input port 40, the air-transported powder is piled up on the lower surface side of the powder storage tank 38, and at the same time, the powder-mixed air used for pneumatic transportation of the powder. Both the intake and exhaust units 12 (12
a, 12b), the filter unit 1
The air separated from the powder through the filter 18 of No. 4 and filtered passes through the intake / exhaust port 22 of the housing 20 and the two-way switching valve 30 and is sucked from the intake port 26 by the fan 24, and the exhaust port 28. Is discharged to the outside through the two-way switching valve 32, the silencer 34, and the outside. That is, in both units 12a and 12b, the air flowing into the powder storage tank 38 is blown into the powder storage tank 38 by the fan 24.
Function to exhaust to the outside of. Here, the powder device 10
Operates so that the amount of air flowing into the powder storage tank 38 due to air transportation is the same as the amount of air exhausted to the outside through the fan 24, and the pressure balance in the powder storage tank 38 (slightly negative) Pressure) does not collapse.

Next, FIG. 2 is a schematic diagram showing an embodiment in which the internal air of the powder storage tank 38 is replaced with the external air after the powder is put into the powder storage tank ventilation device 10 of the present invention. The powder storage tank ventilation device 10 shown in the same figure has two intake and exhaust units 12 included in the above-described powder storage tank ventilation device 10 of the present invention.
Of the intake side two-way switching valve 30 and the exhaust side two-way switching valve 32 of
Among the combinations, the combination of (c) is set, and the air outside the powder storage tank 38 in one intake / exhaust unit 12a is blown by the fan 24 into the powder storage tank 38
Intake and exhaust of the other intake / exhaust unit 12
In b, the air inside the powder storage tank 38 is exhausted to the outside of the powder storage tank 38 by the fan 24.

In this manner, in the ventilation operation mode of the ventilation apparatus 10 for a powder storage tank according to the present invention, in which the intake side two-way switching valve 30 and the exhaust side two-way switching valve 32 are combined, the powder is powdered by air transportation. After being charged into the powder storage tank 38 through the body charging port 40, in the other intake / exhaust unit 12b, the air (powder mixed) present on the upper surface side of the powder storage tank 38 passes through the filter 18 of the filter unit 14. Only the internal air after being filtered and separated from the powder passes through the intake / exhaust port 22 and the two-way switching valve 30 of the housing 20, is sucked by the fan 24 from the intake port 26, and is exhausted from the exhaust port 28.
It is exhausted to the outside of the powder storage tank 38 through the one-way switching valve 32 and the silencer 34. At the same time, in the intake / exhaust unit 12a on one side, the external air flows through the silencer 34,
The air is sucked from the intake port 26 by the fan 24 through the two-way switching valve, exhausted from the exhaust port 28, passes through the two-way switching valve 32, and enters the housing 20 of the filter unit 14 through the intake and exhaust ports 22 of the housing 20. Then, it is introduced into the powder storage tank 38 through the filter 18. That is, it functions so that the internal air of the powder storage tank 38 can be efficiently replaced with the external air to adjust the internal temperature of the powder storage tank 38. In the ventilation device 10, the replacement of the internal air of the powder storage tank 38 with the external air is performed so that the intake air and the exhaust air have the same amount so that the pressure balance (slightly negative pressure) in the powder storage tank 38 is not disturbed. You can and need to be well balanced. This is because when the balance is lost and the pressure in the powder storage tank 38 becomes large negative pressure,
This is because there is a risk of deformation and damage.

In the figure, one intake / exhaust unit 12a sucks external air into the powder storage tank 38, and the other intake / exhaust unit 12b sucks the powder storage tank 3 into the powder storage tank 3.
Although an example of exhausting the internal air of No. 8 to the outside has been shown, conversely to this, one of the intake / exhaust units 12a is used for the powder storage tank 3
8 may be exhausted to the outside, and the other intake / exhaust unit 12b may inject the external air into the powder storage tank 38. That is, in the four combinations of the intake-side two-way switching valve 30 and the exhaust-side two-way switching valve 32 of the two intake / exhaust units 12 of the powder storage tank ventilation device 10 of the present invention described above, As a matter of course, the combination may be set.

FIG. 3 is a schematic view showing an embodiment of backwashing the filter 18 of the ventilation device 10 for a powder storage tank according to the present invention. The ventilation device 10 for a powder storage tank shown in FIG. 1 includes an intake-side two-way switching valve 30 and an exhaust side 2 for two intake / exhaust units 12 (12a, 12b) included in the ventilation device 10 for a powder storage tank of the present invention described above. In the four combinations with the one-way switching valve 32, the combination of (d) is set, and both the intake and exhaust units 12a and 12b use the fan 24 to blow the air outside the powder storage tank 38 into the powder storage tank 38. It is introduced inside.

In the powder storage tank ventilation device 10 backwash operation mode of the present invention in which the intake side two-way switching valve 30 and the exhaust side two-way switching valve 32 are combined in this manner, both intake and exhaust units 12a and 12b. Both suck outside air through the silencer 34 and the two-way switching valve 30 from the intake port 26 by the fan 24, exhaust from the exhaust port 28, enter the filter unit 14 from the intake / exhaust port 22 of the housing 20, and filter the filter 18. It functions so as to be introduced into the inside of the powder storage tank 38. Both intake and exhaust units 12a and 1
The powder adhering to the filter 18 of 2b can be backwashed for cleaning. At this time, the filter unit 1
The backwashing of the filter 18 can be carried out more effectively by simultaneously operating the backwashing device 36 provided in FIG. At this time, the exhaust path of the external air taken in by both the intake and exhaust units 12 is not particularly shown, but for example, the powder inlet 40 of the powder storage tank 38 is used.
Alternatively, an exhaust port or the like may be separately provided.

In the above-mentioned embodiment, one ventilation device 10 for the powder storage tank is used to discharge the powder of the powder into the powder storage tank 38, and to discharge the powder to the powder storage tank 38. The replacement path of the internal air of the powder storage tank 38 after the body is thrown in and the intake path of the external air when the filter 18 of the ventilation device 10 of the powder storage tank is backwashed are shown. The storage tank ventilation device 10 is not limited to this embodiment, and the number of the powder storage tank ventilation devices 10 used and the ventilation amount (intake amount and exhaust amount) per unit time are, for example, powder. Appropriate selection may be made so that the air taken in with the powder when the powder is put into the storage tank 38 can be exhausted. Further, when ventilating the internal air of the powder storage tank 38, the ventilation amount may be appropriately selected in consideration of the time required for ventilation.

[0037]

As described in detail above, the ventilation device for a powder storage tank according to the present invention is the powder mixed air used for pneumatic transportation of powder and flowing into the powder storage tank, or the powder storage tank. A filter unit for separating the powder from the mixed air present in the powder and the transport air or the internal air, and a powder storage tank separated from the powder by the filter unit by appropriately setting two two-way switching valves And a fan unit capable of sucking either one of the transport air or the internal air flowing into the inside and the outside air of the powder storage tank and exhausting it to either the inside or the outside of the powder storage tank. At least two intake and exhaust units are provided.

Therefore, according to the powder storage tank ventilation apparatus of the present invention, the intake side and the exhaust side are appropriately changed by the intake side two-way switching valve and the exhaust side two-way switching valve. By selecting, it is possible to efficiently exhaust the inflowing transport air into the powder storage tank and replace the internal air in the powder storage tank without disturbing the pressure balance in the powder storage tank. It is possible to prevent the dew condensation from occurring in the powder storage tank by adjusting the internal temperature of, and it is also possible to easily clean the filter of the intake / exhaust unit. Further, by providing at least two intake / exhaust units, it is possible to balance the amount of intake air and the amount of exhaust air into the powder storage tank when the air inside the powder storage tank is replaced, and the inside of the powder storage tank is negative. It is possible to prevent pressure and damage to the powder storage tank.

Further, in the present invention, the one having the silencer can reduce the noise during operation,
A filter with a backwashing mechanism can effectively clean the filter, and a pulsejet type backwashing mechanism can also backwash the filter during the filtering operation to improve the filter cleaning effect. This enables continuous operation for a long period of time. Further, if the two-way switching valve has an automatic drive mechanism, it is possible to switch the operation modes extremely easily and fully automatically.

[Brief description of drawings]

FIG. 1 is a schematic view of an embodiment of the present invention when a powder storage tank ventilation device is charged with powder.

FIG. 2 is a schematic view of an example of the ventilation apparatus for a powder storage tank according to the present invention when air is replaced.

FIG. 3 is a schematic view of an example of backwashing the filter of the ventilation device for the powder storage tank of the present invention.

[Explanation of symbols]

 10 Powder Storage Ventilator 12 (12a, 12b) Intake / Exhaust Unit 14 Filter Unit 16 Fan Unit 18 Filter 20 Filter Housing 22 Intake / Exhaust Port 24 Fan 26 Inlet Port 28 Exhaust Port 30 Intake Side Two-way Switching Valve 32 Exhaust Side 2 One-way switching valve 34 Silencer 36 Backwash mechanism 36a Nozzle 36b Supply pipe 36c Solenoid valve 36d Collecting pipe 38 Powder storage tank 40 Powder input port

Claims (5)

[Claims] 1. A filter unit which is provided above a powder storage tank for storing powder charged from a powder charging port, and which separates powder from air, and the air separated by this filter unit to the outside. At least two intake / exhaust units each having a fan unit capable of exhausting air and introducing external air into the filter unit are provided, and the fan unit includes a fan and an intake port of the fan for sucking the filter unit. An intake-side two-way switching valve that switches to either one of an exhaust port and external air, and an exhaust-side two-way switching valve that switches the exhaust port of the fan to one of an intake and exhaust port of the filter unit and external air. A ventilation device for a powder storage tank, which is characterized in that 2. The ventilation device for a powder storage tank according to claim 1, wherein the intake / exhaust unit further includes a silencer arranged between the fan unit and the outside air of the powder storage tank. 3. The powder storage tank ventilation device according to claim 1, wherein the filter unit further has a backwashing mechanism for the filter. 4. The ventilation device for a powder storage tank according to claim 3, wherein the backwashing mechanism of the filter is a mechanism for ejecting a pulse jet to the filter from the separated air side. 5. The powder storage tank ventilation device according to claim 1, wherein the two-way switching valve of the fan unit includes an automatic drive mechanism.