JPH1151576A - Trap unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To capture particles in a gas containing condensates or sublimates efficiently while enhancing the trap efficiency by providing a turning space having an opening in parallel with the flow at a nozzle section, changing the direction of main gas flow at the nozzle section and introducing a part of the particles into the turning space. SOLUTION: The trap unit is inserted into a exhaust line coupling between an incinerator and an external vacuum pump. Gas passes through the outside of a cooling pipe 2 in a tubular body 1 and it is cooled down through adiabatic expansion when passing through a nozzle section 4 and impinges on a cooling plate 3 to which a part of particles adheres. When passing through the nozzle section 4, the particles in the gas is subjected to inertia force and shunted because the direction of main gas flow is changed and introduced from the opening 6 of a partition 5 into a turning space S. The gas is turned in the turning space S and the particles in the gas are blown off centrifugally outwards and separated. Subsequently, the particles are collected and the grown up particle falls down gravitationally and collected below the turning space S.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trapping device which is suitably used as a trapping device for condensing or subliming a gas discharged from various furnaces such as a purifying furnace, a firing furnace and a vacuum sintering furnace. It is about.

[0002]

2. Description of the Related Art As is well known, for example, various sintered materials such as metals and ceramics are produced by molding a raw material powder into a desired shape and then sintering it at a high temperature. In the stage of producing a powder molded product from the raw material powder, various binders are added because it is necessary to ensure the moldability of the powder particles. On the other hand, in the sintering process, the binder acts as a harmful substance having various adverse effects on the sintered product. Therefore, in sintering the powder molded product, the binder contained in the molded product is used as a pre-treatment. Must be removed. Therefore, this type of sintering furnace is provided with a trap device for recovering the binder from the gas containing the binder vapor generated from the molded product during the binder removing step.

[0003] This trap device is interposed in an exhaust line to condense and sublimate the binder from the flowing gas containing the binder to separate it, thereby preventing the binder from being mixed into the exhaust line to the vacuum pump. Play a role. Conventionally, this type of trap device is generally configured such that a plurality of cooling surfaces are provided in a main body through which a gas containing a binder flows, and the binder is trapped on each cooling surface.

More specifically, as shown in FIGS. 10 to 11, a conventional trap device includes a cooling pipe 2 for maintaining a binder in a gas in a main body 1 at a temperature capable of condensing or sublimating the binder.
And a cooling plate 30 cooled by the cooling pipe 2
The cooling plate 303 and the inner periphery 1 of the main body 1 are provided.
and a nozzle portion 304 is provided between the nozzle portion 304 and the nozzle c. Then, the gas is introduced into the trap device and sequentially passed through the nozzle portion 304 in the main body 1 to cool the gas and capture the binder in the gas.

[0005]

However, even in such a conventional trap device, when a binder which is hardly condensed or a vapor of an impurity generated from a molded product is contained, fine sublimated dust is contained in the gas. It often flows to the downstream vacuum pump side while remaining in the vacuum pump. Dust remaining in these gases may cause problems such as obstructing the opening and closing of valves in the piping, and being sucked into the vacuum pump and being mixed into the oil to deteriorate the pump performance or render it inoperable. Was. In addition, there is a danger that the situation will be more serious, such as polluting the atmosphere by discharging dust-containing gas into the atmosphere.

The present invention has been made in view of such a problem, and has as its object to provide a trap device capable of more efficiently trapping particles from a gas containing condensate and sublimate. The purpose is.

[0007]

In order to achieve the above object, the present invention employs a trap device having the following configuration. That is, the trap device of the present invention
A main body having a plurality of cooling surfaces maintained at a temperature at which components in the gas can be condensed or sublimated by cooling, and a nozzle portion provided on the cooling surface of the main body and sequentially passing a gas containing particles is provided. In the trap device for capturing particles in the gas while cooling the gas, a swirl space that opens in parallel with the flow of the nozzle portion is provided, and the direction of the main flow of the gas is changed in the nozzle portion and the inside of the swirl space is changed. Characterized in that a part of the particles is introduced into the substrate.

[0008] With such a structure, the components in the gas are self-cooled by adiabatic expansion when passing through the nozzle portion when flowing through the main body, or are cooled by colliding with the cooling surface. , Condenses or sublimates into mist or dusty particles, some of which are trapped on the cooling surface. On the other hand, a part of the particles in the gas receive the inertial force and diverge from the main flow because the direction of the main flow changes when passing through the nozzle portion, are guided to the swirling space, and swirl in the space. During this swirl, the particles contained in the gas are blown outward by centrifugal force due to their large molecular weight compared to other gas molecules in the gas, and grow during the swirl by the aggregation of the particles, It falls down due to gravity and is caught.

As described above, in addition to cooling the gas sequentially on the cooling surface, the direction of the main flow of the gas is changed at the nozzle portion, and a part of the particles is drawn into the swirling space to effectively capture the particles. Therefore, it is possible to surely improve the trap efficiency as compared with the related art.

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
This will be described with reference to FIG. Parts having the same structure as the conventional example are denoted by the same reference numerals as in FIGS. Further, in this embodiment, a case where particles as impurities contained in a gas have not only a condensability but also a sublimation property will be described.

This trap device is interposed in an exhaust line connecting the sintering furnace and an external vacuum pump, separates condensed and sublimed components from the gas, and prevents these particles from flowing into the vacuum pump. Things. That is, as shown in FIGS. 1 and 2, the trap device has a cylindrical main body 1 having one end 1a connected to an exhaust port of a sintering furnace and the other end 1b connected to a vacuum pump. And a plurality of cooling plates 3 as cooling surfaces supported by the cooling pipes 2.

The cooling pipe 2 cools the cooling plate 3 by flowing cooling water inside. Cooling plate 3
As shown in FIG. 2 and FIG. 3, a substantially disk-shaped metal thin plate alternately arranged at equal intervals in the axial direction of the main body 1 is provided. The nozzle portion 4 having a substantially rectangular opening is formed between the nozzle portion 4 and the partition plate 5. The partition plate 5 protrudes from the front and back surfaces along the longitudinal direction of the main body 1 at the other end facing the one end of the cooling plate 3. As shown in FIG. 4, the cooling plates 3 are arranged so that the nozzle portions 4 of the adjacent cooling plates 3 open alternately symmetrically to allow the gas introduced into the main body 1 to flow sequentially. , And change its direction.
Further, an opening 6 is disposed so as to be opposed to the nozzle portion 4, and a swirling space S is provided at a position surrounded by the inner periphery 1 c of the main body 1 and the partition plate 5. And turn it.

With such a configuration, as shown in FIG. 4, gas passes through the inside of the main body 1 sequentially, and
Self-cooling by adiabatic expansion when passing through, and being cooled by colliding with the cooling plate 3, a part of the particles solidify and adhere to the cooling plate 3. On the other hand, the particles in the gas undergo a change in the direction of the main flow of the gas when passing through the nozzle portion 4, are separated from the main flow by the inertial force, and guided to the swirling space S.
Then, the gas in the swirling space S swirls under the influence of the main flow. During this swirling, the particles contained in the gas are separated and separated by the centrifugal force because the molecular weight is larger than the other gas molecules in the gas, and the particles aggregate and grow. It falls by gravity and is captured below the turning space S.

As described above, in addition to cooling and capturing the main flow of the gas by the cooling plate 3, the particles are effectively captured by drawing the particles into the swirling space S and swirling. As a result, the trap efficiency can be reliably improved. For example, even if the ratio of particles that are not captured and pass through the nozzle units 4 in each stage is 60%, if nine nozzle units 4 are installed in the main body 1, the ratio of particles that pass through all the nozzle units 4 Is 9 in (0.6)
, Ie, at most about 1%.

Since the cooling plate 3 and the partition plate 5 can be easily removed from the main body 1 together with the cooling pipe 2, particles fixed to the cooling plate 3 and the inner periphery 1c of the main body 1 can be easily removed. It becomes possible. In the above-described embodiment, the capturing of particles having condensability or sublimation has been described. However, when the three-phase state of the captured particles is clear, the main body 1 may be heated to an appropriate temperature. By
The particles can be collected in a tank in a liquid phase. In this case, as shown in FIGS. 2 and 3, a notch 7 is provided at the lower end of the cooling plate 3, and the main body 1 is arranged to be inclined in the tank, so that The particles can be collected in the tank in a liquid phase.

On the other hand, when the gas component mainly has sublimability, sublimation proceeds by cooling the main body 1 from the outside, so that trap efficiency can be improved.
In addition, the specific configuration of each unit is not limited to the above-described embodiment, and includes, for example, the following modified examples. First, a first modified example will be described with reference to FIGS.

As shown in FIG. 5, this device has substantially the same structure as that of the above-described embodiment, and is configured so that the gas introduced into the main body 1 can be sequentially circulated as in the above-described embodiment. However, the structure of the cooling plate and the partition plate is different. Note that portions having the same structure as in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

This cooling plate 103 is, as shown in FIG.
In the cooling plate 3 of the above-described embodiment, the nozzle portion 104 has a substantially semi-annular shape, the opening portion 106 is provided in the partition plate 105, and the partition plate 105 is extended to the lower side to provide the stagnation portion 107 below the swirling space S. Things. With such a configuration, the swirling speed of the gas in the stagnation portion 107 is reduced, and the trapping efficiency of the gas containing a large amount of sublimate is more reliably improved.

Next, a second modification will be described with reference to FIGS. Note that portions having the same structure as in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. This trap device, as shown in FIG.
A cooling pipe 2 is disposed in a cylindrical main body 1, and two types of cooling plates 203 A and 203 B are alternately disposed in the cooling pipe 2, and the gas introduced into the main body 1 is similar to the above embodiment. Are arranged so that the cooling plate and the partition plate are different from the above embodiment.

More specifically, as shown in FIG. 8, the cooling plate 203A is provided with a substantially semi-annular notch at the lower end of a disk-shaped thin plate, and the notch extends in the longitudinal direction of the main body 1 in the notch. A cylindrical partition plate 205 is abutted,
The left and right ends of the substantially semi-annular notch are further cut inward to form a nozzle portion 204A. Partition plate 20
5 is an opening 206 at a position facing the nozzle 204A.
To form a swirling space S that is surrounded by the inner periphery 1c of the main body 1 and the partition plate 205 and communicates with the nozzle portion 204A through the opening 206, and has a stagnation portion 20 below it.
7 are formed.

As shown in FIG. 9, the cooling plate 203B is provided with a notch at the upper end of a disk-shaped thin plate to form a nozzle portion 204B.
Is formed. With such a configuration, as shown in FIG. 7, the main flow of the gas containing particles is:
When a parallel flow is created and distributed in the main body 1, the cooling plate 20
3A and 203B, self-cooled and condensed or sublimated, or collided with the cooling plates 203A and 203B and captured. On the other hand, some of the particles receive an inertial force when passing through the nozzle portion 204A, and are diverted from the main stream, and the opening 206
Is led to the turning space S, and turns inside the space S. During this swirling, the particles contained in the gas have a higher molecular weight than the other gas molecules in the gas, so they are blown off by centrifugal force and separated, and agglomerated during the swirling to increase the particle size and the gravity. As a result, it falls to the lower stagnation portion 207 and is captured.

It is needless to say that the first and second modifications can provide the same effects as those of the above-described embodiment, and that various modifications can be made to the applied particles and the like. For example, the trap device can also be applied as a dust collector for removing dust in a high-temperature gas. Also,
Condensable paraffin vapor or mist may be mixed into the sublimable gas, captured together in the trap device, and the dust may be loaded on the liquid phase of the mist and captured in the tank.

Further, the nozzle portions 4, 10 as described above
4, 204A and 204B can also expect the effect of aggregating particles by vibrating gas like a flute sound wave,
Further, the nozzle units 4, 104, 204A, 2
04B is also expected to have the effect of charging the particles when passing through the gas and aggregating the particles by static electricity.
Further, the cooling plates 3, 103, 203A, 203B and the main body 1
A voltage may be positively applied between the opposing surfaces to electrostatically adsorb the particles on one of the opposing surfaces.

In addition, various modifications can be made without departing from the spirit of the present invention, such as forming the main body 1 and the cooling plate 3 in a rectangular shape.

[0024]

The present invention is embodied in the form described above and has the following effects. That is, the trap device of the present invention is effective in that the main flow of gas is self-cooled at the nozzle portion or cooled at the cooling surface to capture particles, and a part of the particles is drawn into the swirling space and swirled. Trapping particles, it is possible to improve the trapping efficiency more reliably than before, and prevent the gas containing particles from flowing out to the vacuum pump or the outside, thereby deteriorating the vacuum pump. Alternatively, problems such as inoperability and problems such as air pollution can be effectively solved.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing one embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along line AA in FIG.

FIG. 3 is a view showing the cooling plate.

FIG. 4 is an explanatory view of the operation.

FIG. 5 is a schematic longitudinal sectional view showing a first modification of the present invention.

FIG. 6 is an enlarged sectional view taken along line BB in FIG. 5;

FIG. 7 is a schematic longitudinal sectional view showing a second modification of the present invention.

FIG. 8 is an enlarged sectional view taken along line CC in FIG. 7;

FIG. 9 is an enlarged sectional view taken along line DD in FIG. 7;

FIG. 10 is a schematic longitudinal sectional view showing a conventional example.

FIG. 11 is an enlarged sectional view taken along line EE in FIG. 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Main body 3, 103, 203A, 203B ... Cooling surface (cooling plate) 4, 104, 204A, 204B ... Nozzle part S ... Swirling space

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Ryunosuke Yamada 1-8-1, Tsukuwa, Otsu-shi, Shiga Prefecture Shimadzu Mectem Corporation

Claims (1)

[Claims] 1. A main body having a plurality of cooling surfaces maintained at a temperature at which components in a gas can be condensed or sublimated by cooling, and a nozzle portion provided on the cooling surface of the main body and sequentially passing a gas containing particles. In a trap device for capturing particles in a gas while cooling the gas, a swirling space that opens in parallel with the flow of the nozzle portion is provided, and a direction of a main flow of the gas is changed in the nozzle portion. And a part of the particles is introduced into the swirling space.