JP2019174060A - Local exhaust ventilation system - Google Patents

Abstract

A local exhaust device capable of maintaining a required control wind speed while reducing an intake air flow amount is provided. A local exhaust device (E) of the present invention is installed in an opening (7o) of a container (7) for handling powder, air passing through an inner cylinder (1) flows into the container (7), and an air flow between the outer cylinder (2) and the inner cylinder (1). The gas is discharged to the exhaust port 2s1 through the gap 2i disposed therebetween. [Selection diagram] Fig. 1

Description

  The present invention relates to a local exhaust device.

Conventionally, in the production process of highly pharmacologically active substances such as pharmaceuticals and active pharmaceutical ingredients, it is necessary to prevent exposure to workers and cross-contamination between products due to generation of dust. Therefore, in the manufacturing process, a dust containment technique is applied.
When the wet highly pharmacologically active substance is dried and recovered as a powder, a conical dryer having a slope with a lower center side is used at the bottom to facilitate recovery.

In the conical dryer, most of the dried powder slides down the slope and is collected in a collection container installed at the bottom. However, a part remains on the wall surface of the conical dryer and is difficult to recover as it is.
Therefore, the worker scrapes out the residual powder adhering to the wall surface from the opening at the top of the conical dryer to the bottom container using, for example, a scraping jig having a long handle. At that time, it is necessary to provide local exhaust equipment so that the powder that has soared at the opening at the top of the conical dryer does not scatter to the worker and the work environment.

  The local exhaust system is installed at or near the tank opening, sucks the generated dust together with the surrounding air, passes through the exhaust duct, passes through a precision filter such as a HEPA filter, and after removing the contained dust, the general exhaust system It is common to join. Proper design of local exhaust equipment and prevention of dust scattering in the work environment are important for work environment conservation and product quality control.

For example, Patent Document 1 discloses a semicircular local exhaust device attached to an upper portion of a tank. Patent Document 2 discloses an all-round local exhaust device.
In the local exhaust devices of Patent Documents 1 and 2, wind speed parallel to the opening surface is generated, and dust generated together with surrounding air is sucked.

Japanese Patent No. 5576316 US6253330B1 publication

  By the way, in the local exhaust apparatus of patent document 1, internal visibility can be improved by making it a semicircle shape, and workability | operativity can be improved. However, the wind speed decreases as the distance from the air inlet increases as air near the opening is more easily sucked. For this reason, the shortage distribution becomes large and it is necessary to suck in a large amount of air.

  In the local exhaust device of Patent Document 2, a slit is provided on the side wall, and air is sucked in the horizontal direction of the opening. However, the wind speed is uneven, and a large air volume is required to produce a predetermined wind speed at the center.

  The present invention has been devised in view of the above circumstances, and an object thereof is to provide a local exhaust device capable of maintaining a necessary control wind speed while reducing an intake air volume.

  In order to solve the above problems, the local exhaust device of the first aspect of the present invention is installed in an opening of a container for handling powder, and air passing through the inner cylinder flows into the container, and the outer cylinder, the inner cylinder, It passes through the gap arranged between the two and is discharged to the exhaust port.

  In the local exhaust device of the second aspect of the present invention, an intake hole through which air outside the container flows is disposed inside the container that handles the powder.

  ADVANTAGE OF THE INVENTION According to this invention, the local exhaust apparatus which can maintain required control wind speed can be provided, reducing intake air volume.

The front sectional view showing typically the flow of the air at the time of attachment of the local exhaust device concerning the embodiment of the present invention, the tank, and the local exhaust device. The typical disassembly sectional drawing of the local exhaust apparatus and tank of embodiment. The disassembled perspective view of the local exhaust apparatus and tank of embodiment. The typical sectional view showing the assembly process to the tank of a local exhaust device. The typical sectional view showing the assembly process to the tank of a local exhaust device. The typical sectional view showing the assembly process to the tank of a local exhaust device. The perspective perspective view which shows the assembly state of a local exhaust apparatus, and an exhaust flow path with the thick broken line arrow. The top view seen from the upper direction at the time of installing a local exhaust apparatus on a tank. The figure which compares the exhaust air volume with the local exhaust apparatus of embodiment, and the exhaust air volume with the all-circular type | mold which implement | achieves a control wind speed in the horizontal direction from the hole opened on the conventional circumference, and a control wind speed. The disassembled perspective view of the local exhaust apparatus and tank of a modification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
These embodiments are preferred specific examples of the present invention, and may have various technically preferable limitations. However, the technical scope of the present invention is not particularly limited unless otherwise specified. It is not limited to these aspects.

FIG. 1 is a front sectional view schematically showing an air flow when the local exhaust device E, the tank 7 and the local exhaust device E according to the embodiment of the present invention are attached.
When the wet highly pharmacologically active substance is dried and recovered as a powder, for example, a conical dryer having a tank 7 having a slope with a lower center side is used at the bottom for easy recovery.

  In the conical dryer, most of the dried powder slides down the inclined wall surface 7k of the tank 7 and is collected in a collection container (not shown) installed at the bottom. However, a part remains on the inclined wall surface of the tank 7 and is difficult to collect as it is.

  Therefore, the operator P uses the opening 7o at the top of the tank 7 to remove residual powder adhering to the inclined wall surface 7k of the tank 7 using a scraping jig 14 with a long handle, for example. Scrape out into a collection container (not shown) provided on the bottom 7t.

At that time, the local exhaust device E of the embodiment is provided so that the powder that has soared in the opening 7o at the upper part of the tank 7 does not scatter to the worker P and the working environment.
The local exhaust device E of the embodiment is installed on the tank 7 via the packing 4.

FIG. 2 is a schematic exploded sectional view of the local exhaust device E and the tank 7 of the embodiment. FIG. 3 is an exploded perspective view of the local exhaust device E and the tank 7 according to the embodiment.
The local exhaust device E includes an inner cylinder 1 and an outer cylinder 2.

For the inner cylinder 1 and the outer cylinder 2, a material having corrosion resistance, for example, stainless steel is used. Note that other materials may be used as long as they have corrosion resistance.
The inner cylinder 1 has an inner cylinder peripheral plate 1s and an inner cylinder upper plate 1u.

The inner cylinder peripheral plate 1s is formed in a cylindrical shape.
The inner cylinder upper plate 1u is an annular plate material extending outward from the upper edge of the inner cylinder peripheral plate 1s. A pair of inner cylinder handles 6 are installed on the inner cylinder upper plate 1u.

An annular packing 4a (see FIG. 2) is installed below the inner cylinder upper plate 1u. In addition, you may comprise without using the packing 4a.
The outer cylinder 2 includes an outer cylinder peripheral plate 2s, an outer cylinder upper plate 2o, an outer cylinder lower plate 2u, a guide cylinder 2a, and an exhaust duct connection portion 3.

The outer cylinder peripheral plate 2s is formed in a cylindrical shape having a diameter larger than the outer diameter of the inner cylinder peripheral plate 1s of the inner cylinder 1. As a result, an annular space gap 2i (see FIG. 1) is formed between the outer cylinder peripheral plate 2s of the outer cylinder 2 and the inner cylinder peripheral plate 1s of the inner cylinder 1.
An opening 2s1 (see FIG. 3) is formed in a part of the outer cylinder peripheral plate 2s. A cylindrical exhaust duct connecting portion 3 that is an exhaust hole is connected to the opening 2s1.

  The outer cylinder upper plate 2o is an annular plate extending inward from the upper edge of the outer cylinder peripheral plate 2s. A pair of outer cylinder handles 5 are attached on the outer cylinder upper plate 2o. Since the inner diameter s2 of the opening 2o1 of the outer cylinder upper plate 2o is used for positioning the outer cylinder 2 and the inner cylinder 1, it is set slightly larger than the outer diameter s1 of the inner cylinder peripheral plate 1s of the inner cylinder 1.

As shown in FIG. 2, the outer cylinder lower plate 2u is an annular plate extending inward from the lower edge of the outer cylinder peripheral plate 2s.
The guide cylinder 2a has a cylindrical shape extending downward from the inner edge of the outer cylinder lower plate 2u. Since the outer diameter s3 of the guide cylinder 2a is used for positioning the outer cylinder 2 and the tank 7, it is set slightly smaller than the inner diameter s4 of the opening 7o of the tank 7.

An annular packing 4 is installed at the connecting portion between the outer cylinder lower plate 2u and the guide cylinder 2a. The packings 4 and 4a are made of silicone rubber, EPDM rubber (Ethylene propylen diene rubber) or the like.
Note that the packing 4 may not be used.

  With the above configuration, the lower portion between the inner cylinder peripheral plate 1s of the inner cylinder 1 and the outer cylinder peripheral plate 2s of the outer cylinder 2 is formed with an intake hole Ei (see FIG. 1) over the entire circumference. Air taken in from the intake hole Ei is sucked into the gap 2i between the outer cylinder 2 and the inner cylinder 1.

As shown in FIG. 1, an exhaust system is connected to an exhaust duct connection portion 3 of the outer cylinder 2.
As an exhaust system, a HEPA filter 9 is attached upstream of the exhaust fan 10. An exhaust system 11 such as an exhaust duct is connected downstream of the exhaust fan 10.

The exhaust duct connecting portion 3 of the outer cylinder 2 is connected to the HEPA filter 9 via the exhaust duct 8. That is, the exhaust duct 8 connected to the HEPA filter 9 and the exhaust duct connection part 3 of the outer cylinder 2 are connected.
The above-described local exhaust device E is used as follows.

By operating the exhaust fan 10, as shown in FIG. 1, air flows in from the outside through the opening surface 1 o of the inner cylinder 1 (arrow α <b> 11 in FIG. 1).
The inflowing air is sucked from the suction hole Ei together with the powder generated inside the tank 7 and taken into a gap 2i formed between the inner cylinder 1 and the outer cylinder 2. The taken-in air passes through the gap 2i (arrow α13 in FIG. 1), passes through the exhaust duct connection portion 3, and is discharged to the exhaust duct 8 (arrow α14 in FIG. 1). The inflowing air is discharged together with the powder through the exhaust duct 8 (arrow α15 in FIG. 1).

  At this time, as shown in FIG. 1, almost all of the exhausted air is air that has passed through the inner cylinder 1 in the vertical direction (arrow α11 in FIG. 1). The lower part of the inner cylinder 1 is located below the height of the opening surface 7o1 of the opening 7o of the tank 7. Thereby, the air direction at the height position of the opening surface 7o1 of the tank 7 is made uniform.

  As a result, the powder generated inside the tank 7 cannot rise against the air (arrow α11 in FIG. 1) entering the inner cylinder 1 and flows into the inner cylinder 1 and the outer cylinder from the annular intake hole Ei. 2 passes through the gap 2i between the two, and is exhausted through the exhaust duct connection portion 3 and the exhaust duct 8 (arrow α15 in FIG. 1). Therefore, it is possible to suppress the worker P from being exposed to the powder as much as possible.

  The assembly of the local exhaust device E as an example to the tank 7 is performed as follows.

  4 to 6 are schematic cross-sectional views showing the process of assembling the local exhaust device E to the tank 7. 4 to 6, the worker P is omitted.

As shown in FIG. 4, the worker P attaches the packing 4 to the outer cylinder 2. At this time, an adhesive may or may not be used.
The operator P holds the outer cylinder handle 5 to lift the outer cylinder 2, inserts the guide cylinder 2 a of the outer cylinder 2 into the opening 7 o of the tank 7, and places the outer cylinder 2 in the opening 7 o of the tank 7. (See FIG. 5).

  Then, as shown in FIG. 6, the worker P holds the inner cylinder handle 6 to lift the inner cylinder 1 and places the inner cylinder peripheral plate 1 s of the inner cylinder 1 on the opening 7 o of the tank 7. The cylinder 2 is fitted into the opening 2o1 of the outer cylinder upper plate 2o, and the inner cylinder 1 is placed on the outer cylinder 2 on the tank 7 (see FIG. 7).

An annular space gap 2 i is formed between the inner cylinder 1 and the outer cylinder 2. FIG. 7 is a perspective perspective view showing the assembled state of the local exhaust device E and the exhaust flow path with thick broken line arrows. In FIG. 7, the air flow is indicated by a thick broken line.
As a result, the local exhaust device E is installed in the opening 7 o of the tank 7. Then, as shown in FIG. 1, the exhaust duct connecting portion 3 of the outer cylinder 2 and the exhaust duct 8 to which the HEPA filter 9 and the like are connected are connected.

FIG. 1 shows an example in which the inner cylinder 1 and the outer cylinder 2 can be disassembled. And in order to improve operativity at the time of installing each, although the outer cylinder handle 5 and the inner cylinder handle 6 were illustrated, the presence or absence of a handle is not limited and is arbitrary.
Moreover, although the case where the inner cylinder 1 and the outer cylinder 2 were separate members was shown, this is to improve the cleaning performance of the inner cylinder 1 and the outer cylinder 2. On the other hand, it is possible to adopt an integral configuration in which the inner cylinder 1 and the outer cylinder 2 are fixed.

<Exhaust air volume and control air speed at the exhaust fan 10>
FIG. 8 is a top view seen from above when the local exhaust device E is installed on the tank 7. (1)-(4) of FIG. 8 has shown the measurement point of the wind speed.

With the configuration shown in FIG. 1, the wind speed distribution at the position of the opening surface 1 o of the inner cylinder 1 when the exhaust air volume at the exhaust fan 10 was set to 4.02 m ³ / min was measured.
As shown in FIG. 8, Table 1 shows the result of measuring the control wind speed at each measurement point (1) to (4) by dividing the opening surface 1o into four (1) to (4). The control wind speed is the wind speed at the opening surface 1o.

Among the measurement points (1) to (4), the maximum was 0.90 m / s of (1) and the minimum was 0.76 m / s of (3). The difference is 0.14 m / s. The average of the measured wind speed at the measurement points (1) to (4) was 0.80 m / s.
Therefore, generally consistent control wind speeds were obtained at all the measurement points (1) to (4) on the opening surface 1o of the inner cylinder 1.

FIG. 9 shows the exhaust air volume and the control of the local exhaust device E of the embodiment and the conventional circular exhaust system that achieves the control wind speed by sucking in the horizontal direction from the hole (corresponding to the opening surface 1o) drilled on the circumference. It is a figure which compares a wind speed. The horizontal axis represents the exhaust air volume (m ³ / min), and the vertical axis represents the control wind speed (m / s). The exhaust air volume is the air volume of the exhaust fan (corresponding to the exhaust fan 10).

Conventional off-the-shelf (for example, Patent Document 2) ready-made products require an exhaust air volume of about 19 m ³ / min (cubic meter per minute) in order to achieve a control wind speed of 0.5 m / s (meter per second). is there.
On the other hand, in the local exhaust device E of the embodiment, 4 m ³ / min is sufficient to realize a control wind speed of 0.8 m / s.

Therefore, in the local exhaust apparatus E of embodiment, it was confirmed that the exhaust air volume of the exhaust fan 10 can be reduced significantly.
In addition, it was confirmed that the leakage of the powder from the container 7 can be suppressed if the wind speed at the opening surface 1o of the inner cylinder 1 is 0.1 m / s or more. That is, if the wind speed at the opening surface 1o is 0.1 m / s or more, the backflow of the powder from the container 7 can be suppressed.

According to the local exhaust device E having the above configuration, since air is once sucked into the tank 7, it is possible to suppress the worker P from sucking the substance in the tank 7 as much as possible.
Further, the exhaust air volume of the exhaust fan 10 can be reduced.

Furthermore, since the intake hole Ei of the local exhaust device E is formed over the entire circumference of the opening 7o of the tank 7, the unevenness of the air sucked through the opening 7o is reduced.
In addition, since the local exhaust device E is divided into the inner cylinder 1 and the outer cylinder 2, cleaning is easy. Further, since the inner cylinder 1 and the outer cylinder 2 are divided, the weight is light and easy to handle.

Further, by installing the packing 4, leakage of air from between the container 7 and the outer cylinder 2 can be suppressed. In addition, damage to the outer cylinder 2 and the tank 7 is suppressed by using the packing 4.
Similarly, the leakage of air from between the inner cylinder 1 and the outer cylinder 2 can be suppressed by installing the packing 4a. In addition, damage to the outer cylinder 2 and the inner cylinder 1 is suppressed by using the packing 4a.

  Therefore, it is possible to provide the local exhaust device E that can maintain the necessary control wind speed while reducing the intake air volume (exhaust air volume).

<< Modification >>
FIG. 10 is an exploded perspective view of the local exhaust device 2E and the tank 7 according to a modification.
The modified local exhaust device 2E is configured such that the inner cylinder upper plate 1u of the inner cylinder 1 of the embodiment is widely formed as indicated by reference numeral 21u in FIG. 10 and the outer cylinder upper plate 2o of the outer cylinder 2 is eliminated. is there.

Since other configurations are the same as those in the embodiment, they are denoted by reference numerals in the 20s, and detailed description thereof is omitted as appropriate.
The modified local exhaust device 2 </ b> E includes an inner cylinder 21, an outer cylinder 22, and a packing 24.
The inner cylinder 21 includes an inner cylinder peripheral plate 21s and an inner cylinder upper wide plate 21u.

The inner cylinder peripheral plate 21s is formed in a cylindrical shape.
The inner cylinder upper wide plate 21u is an annular plate extending widely outward from the upper edge of the inner cylinder peripheral plate 21s. The outer diameter s5 of the inner cylinder upper wide plate 21u is set to be equal to or larger than the outer diameter s6 of the outer cylinder 22. On the inner cylinder upper wide plate 21, a pair of inner cylinder handles 26 are attached.

The outer cylinder 22 includes an outer cylinder peripheral plate 22s, an outer cylinder lower plate 22u, a guide cylinder 22a, and an exhaust duct connection portion 23.
The outer cylinder peripheral plate 22s is formed in a cylindrical shape having a larger diameter than the outer diameter of the inner cylinder peripheral plate 21s of the inner cylinder 21. A gap 22 i that is an annular space is formed between the inner cylinder peripheral plate 21 s of the inner cylinder 21 and the outer cylinder peripheral plate 22 s of the outer cylinder 22.

An opening 22s1 is formed in a part of the outer cylinder peripheral plate 22s. A cylindrical exhaust duct connection portion 23 is connected to the opening 22s1.
An outer cylinder handle 25 is attached to the outer cylinder circumferential plate 22s.

The outer cylinder lower plate 22u is an annular plate extending inward from the lower edge of the outer cylinder peripheral plate 22s.
The guide cylinder 22a has a cylindrical shape extending downward from the inner edge of the outer cylinder lower plate 22u. The outer diameter s7 of the guide tube 22a is set slightly smaller than the inner diameter s8 of the opening 7o of the tank 7.

An annular packing 24 is installed at a connection location between the outer cylinder lower plate 22u and the guide cylinder 22a. Note that the packing 24 may be omitted.
As in the embodiment, the local exhaust device 2E is assembled after inserting the guide tube 22a of the outer tube 22 into the opening 7o of the tank 7 and placing the outer tube 22 provided with the annular packing 24 inside. The cylinder 21 is placed on the outer cylinder 22.

That is, the worker P holds the outer cylinder handle 25 provided with the packing 24 to hold the outer cylinder 22, inserts the guide cylinder 22 a of the outer cylinder 22 into the opening 7 o of the tank 7, and installs the outer cylinder 22 into the tank. 7 is placed in the opening 7o.
The operator P holds the inner cylinder handle 26 to hold the inner cylinder 1, and the outer cylinder circumference of the outer cylinder 22 in which the inner cylinder peripheral plate 21 s of the inner cylinder 21 is placed in the opening 7 o of the tank 7. The inner cylinder 21 is placed on the outer cylinder 22 by being inserted into the plate 22s. Between the inner cylinder 21 and the outer cylinder 22, an annular space gap 22i is formed.

According to the modified example, since the outer cylinder upper plate (see reference numeral 2o in FIGS. 2 and 3) of the outer cylinder 22 is not provided, the inside of the outer cylinder peripheral plate 22s can be easily cleaned. Therefore, it is easy to clean the outer cylinder 22, and the cleaning performance of the local exhaust device 2E is excellent.
Moreover, since the inner cylinder 21 and the outer cylinder 22 are divided | segmented, it is lightweight and workability | operativity is good.

<< Other Embodiments >>
1. In the above-described embodiment, the case where the intake holes Ei of the local exhaust device E are continuously formed around the entire periphery of the inlet of the tank 7 is exemplified. By forming the intake holes Ei over the entire circumference of the inlet of the tank 7, a nearly uniform control wind speed can be obtained.

2. In the above embodiment, the case where the local exhaust device E is configured by the inner cylinders 1, 21 and the outer cylinders 2, 22 is exemplified, but if the intake hole Ei is inside the tank 7, other configurations are adopted. Also good.

3. In the above embodiment, the case where the packings 4 and 4a (24 and 24a) are provided has been illustrated. However, only the packing 4 (24) and the packing 4a (24a) may be provided.

4). The present invention is not limited to the embodiments described above, and includes various modifications. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to the one having all the configurations described. A part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is also possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

1,21 Inner cylinder 1o, 21o Opening surface (opening)
1u Inner cylinder upper plate (upper plate)
2, 22 Outer cylinder 2i, 22i Clearance (gap)
2o Outer cylinder upper plate (upper plate)
3, 23 Exhaust duct connection part (exhaust port)
4, 24, 4a, 24a Packing (seal material)
7 Container 7o Opening (Inlet of container)
21u inner cylinder upper wide plate (upper plate)
E, 2E Local exhaust system Ei Intake hole

Claims (8)

It is installed at the opening of a container that handles powder,
Air passing through the inner cylinder flows into the container,
Through a gap arranged between the outer cylinder and the inner cylinder,
A local exhaust device which is discharged to an exhaust port. The local exhaust system according to claim 1, wherein
The outer cylinder is installed at the opening of the container for handling powder, and has the exhaust port,
The inner cylinder is installed in the outer cylinder with the gap between the inner cylinder and the outer cylinder,
An upper plate provided between the outer cylinder and the inner cylinder and closing the opposite side of the container in the gap;
A local exhaust device comprising: an air intake hole disposed in the container and into which air that has flowed into the container from the outside flows into the gap. The local exhaust system according to claim 1, wherein
The local exhaust device, wherein the outer cylinder and the inner cylinder have a divided structure. The local exhaust system according to claim 1, wherein
The local exhaust apparatus, wherein a control wind speed of air flowing into the container at an opening at an upper portion of the inner cylinder is 0.1 m / s or more. The local exhaust system according to claim 1, wherein
A local exhaust device, wherein a sealing material is provided between at least one of the outer cylinder and the container or between the outer cylinder and the inner cylinder. The local exhaust system according to claim 1, wherein
The outer cylinder and the inner cylinder are divided structures,
A local exhaust device comprising an upper plate provided in the inner cylinder without being provided in the outer cylinder. A local exhaust apparatus, wherein an air intake hole through which air outside the container flows is disposed inside a container that handles powder. The local exhaust system according to claim 7,
The local exhaust device, wherein the intake hole is provided over the entire circumference of the inlet of the container.

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