JPS628540Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a dust collection head for radioactive dust, particularly a dust collection head installed at a suction port of a suction conduit piped to a measurement point for radioactive dust.

At facilities that handle radioisotopes such as hospitals and various research institutes, or nuclear facilities such as nuclear power plants, nuclear fuel plants, and radioactive waste processing plants, air pollution around these facilities is a problem, and radioactive dust contained in the air is a problem. Measurement is required.

For this reason, traditionally, a suction conduit was installed at each measurement point, a dust collection head was attached to each suction port of this suction conduit, paper was attached to each of these dust collection heads, and air was sucked into the suction conduit. A dust collector is used that collects radioactive dust on paper in the dust collection head. In such an apparatus, it is necessary to take out the paper on which radioactive dust has been collected from the dust collection head for measurement, and to attach a new paper to the dust collection head for the next measurement. In general, there are many dust collection heads depending on the measurement location, so in order to reduce the radiation exposure of those who replace the paper, each dust collection head is required to have a structure that allows the paper to be replaced in an extremely short time. Ru.

1 and 2 are detailed explanatory diagrams of a conventionally used dust collecting head. In the figure, 10
1 is a suction conduit piped to the measurement location, and a dust collection head 14 is fixed to the suction port 10a of this conduit 10 via a flow meter 12. 16 is dust collection port 1
8, the dust collection head body has a dust collection port 1.
8 is provided with a mesh plate 20 for holding paper. Then, the paper 22 is placed on the front surface of the mesh plate 20, the cap 24 is screwed into the main body 16, the paper 22 is clamped and held between the cap 24 and the main body 16, and the gasket 26 inside the cap 24 is used to secure the paper 22. The clamping area is kept airtight.

However, in a dust collection head with such a structure, when replacing the paper 22, the operator rotates and removes the cap 24, and then removes the removed cap 2.
It is necessary to place the cap 24 on a returnable box or hold it in the left hand, pick out the paper 22 with tweezers, attach a new paper, and then screw the cap 24 into the main body 16. However, in order to maintain sufficient airtightness at the attachment point between the cap 24 and the main body 16,
The screw-in stroke must be increased, and for this reason, the cap 24 required for attaching and detaching the cap 24 is
The disadvantage was that the number of revolutions of the machine increased and it took a lot of work.
Further, since the cap 24 is completely detached from the main body 16, there is a drawback that the cap 24 gets in the way when replacing the paper 22.

This invention was developed in view of the conventional problems mentioned above, and its purpose is to enable paper replacement in a short time with simple operations, and as a result, reduce the radiation exposure of workers who replace paper. The object of the present invention is to provide a dust collection head for radioactive dust that can be used to collect radioactive dust.

In order to achieve the above object, the dust collection head of the present invention includes a dust collection head body having a dust collection port connected to the suction port of the suction conduit, and a dust collection head body that is airtightly provided around the dust collection port. a mesh plate for holding paper that is elastically supported by the packing; a paper holding door that is pivotally supported on the main body of the dust collecting head so as to be openable and closable and has an opening at a position opposite to the dust collecting port; The present invention is characterized by comprising a piece of paper that is dropped into a concave paper pocket provided at the opening of the paper holding door and is hermetically pressed by the gasket when the door is closed.

Next, a preferred embodiment of the present invention will be described based on the drawings. Note that the same reference numerals are given to the parts corresponding to those in the conventional example described above, and the explanation thereof will be omitted.

FIG. 3 is an exploded sectional view of the dust collecting head according to the present invention. In the figure, a ring-shaped packing 30 is adhesively fixed around the dust collecting port 18 of the dust collecting head main body 16, and a mesh plate 20 for holding paper is elastically held by this packing 30. Reference numeral 32 denotes a paper holding door, which is supported by a butterfly plate 34 (see FIGS. 4 and 5) disposed at one end of the head body 16 so as to be openable and closable with respect to the head body 16. FIG. 4 shows the door 32 in a closed state, and FIG. 5 shows the door 32 in an open state. An opening 36 is provided in the center of the door 32 so as to face the dust collection port 18 of the head body 16, and on the back side of the door 32, as shown in FIG. A concave paper pocket 38 is provided along the pocket 38, and the paper 22 is inserted into the pocket 38. Above the opening 36, the tip of a tweezers for attaching and removing the paper 22 is inserted into the pocket 38. A tweezers insertion port 40 is provided.

42 is a locking device for the door 32, in which a pair of opposing boards 44a and 44b are fixed to the head main body 16 and the door 32, round holes 46a and 46b are provided at opposing positions of the boards 44a and 44b, and the door is locked. 32
It is formed by attaching Nylatsu (registered trademark) 48 to the side substrate 44a. Nairatsuchi 48 above
As shown in FIG. 6, the round hole 46 of the board 44a
A grommet 4 that is engaged and fixed to a and whose split end is inserted into a round hole 46b of another board 44b.
8a, and a plunger 48b which is inserted into the grommet 48a and pushes open the split end of the grommet 48a. Therefore, door 32
When the plunger 48b is closed, insert the plunger 48b into the grommet 4.
8a, it will open into the round hole 46b of the other board 44b.
The split tip of the grommet 48a inserted into the grommet 48a is pushed open around the periphery. As a result, the tip of the grommet 48a fixed to one substrate 44a is prevented from coming out from the round hole 46b of the other substrate 44b, and the door 32 is locked in the closed state. In this way, when opening the locked door 32, the plunger 48b can be pulled toward the user. As a result, the tip of the grommet 48a closes to its original position, the plunger 48b can be pulled out from the round hole 46b of the other board 44b, and the lock is released. In this way, when the locking device 42 is used with the nail latch 48, it can be locked and unlocked with a single touch, which is convenient.

Also, if necessary, a third
As shown in the figure, a hose connection port 50 can be attached. The hose connection port 50 is attached to the door 32 by threading a thread provided on the outer wall of the hose connection port 50 into a thread groove provided on the inner wall of the opening 36 of the door 32.

Further, a ring-shaped groove 52 is provided on the end surface of the head body 16 at the outer periphery of the packing 30, and an airtight ring 54 is fixed within this groove 52.

The present invention consists of the above configuration, and its operation will be explained next.

First, when the door 32 is in the closed state as shown in FIG. 4, the plunger 48b of the nail latch 48 is pulled forward to unlock the locking device 42 and the door 32 is opened. Then, with the door 32 open as shown in FIG. 5, the tip of the tweezers is inserted into the insertion port 40 and the paper 22 inside the pocket 38 is taken out. Thereafter, a new piece of paper 22 is dropped into the pocket 38 using tweezers, and the door 32 is closed and locked. In this state, the paper 22 is
and the door 32, and the airtight ring 54 is also airtightly fitted between the head body 16 and the door 32, so that air flows into the dust collection port 18 from the direction of the end surface of the paper 22. is prevented.

Thereafter, suction of air by the suction conduit 10 is started. As a result, air is sucked into the dust collection port 18 from the opening 36 via the paper 22 and the mesh plate 20, its flow rate is measured by the flow meter 12, and the air is further sucked into the suction port 10a of the suction conduit 10. Radioactive dust in the air during this passage is collected on the paper 22. Then, the paper 22 on which the radioactive dust was collected in this way was used for measurement as described above.
The locking device 42 is unlocked, the door 32 is opened and the paper 22 is taken out using tweezers or the like, a new paper 22 is dropped into the pocket 38, and the door 32 is closed and locked.

In this embodiment, a locking device using a nylon lock is shown, but the locking device is not limited to this, and other locking devices such as a clasp may be used.

According to the present invention, by pivotally holding the paper holding door on the main body of the dust collection head, it is possible to create a structure that does not require screwing, which conventionally caused a decrease in work efficiency. Since the door is held in the main body of the head, there is a large degree of freedom in the hands and paper can be easily replaced.Also, paper can be inserted into the concave paper pocket provided on the door. Even when replacing the paper using tweezers or the like, the paper can be securely held in the paper pocket. As a result, the paper in the dust collection head can be replaced easily and quickly, and workers are prevented from being exposed to unnecessary radiation.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of a conventional dust collection head for radioactive dust, Fig. 2 is a front view of a conventional dust collection head, Fig. 3 is an exploded sectional view of the dust collection head according to the present invention, and Fig. 4 is a side sectional view of a conventional dust collection head. FIG. 5 is a front view showing the door in the closed state, FIG. 5 is a front view showing the door in the open state, and FIG. 6 is a right side view of FIG. 4. The same members in each figure are given the same reference numerals, 10 is the suction conduit, 10a is the suction port, 16 is the dust collection head body, 18 is the dust collection port, 20 is the mesh plate, 22 is the paper, 30 is the packing, 32 is the door, 36 is the opening,
38 is a concave paper pocket, and 54 is an airtight ring.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A dust collection head body having a dust collection port connected to the suction port of the suction conduit, a gasket airtightly provided around the dust collection port of the dust collection head main body, A mesh plate for holding paper that is elastically supported by the packing; a paper holding door that is pivotally supported on the dust collection head body so as to be openable and closable and has an opening at a position opposite to the dust collection port; A dust collecting head for radioactive dust, comprising: a piece of paper that is inserted into a concave paper pocket provided in an opening and is hermetically pressed by the gasket when the door is closed. (2) A collection of radioactive dust, characterized in that, in the dust collection head described in claim (1) of the utility model registration, an airtight ring is provided between the dust collection head main body and the door along the outer edge of the paper. Dust head.