JPH07313824A - Trap for vacuum piping - Google Patents

Abstract

PURPOSE:To prevent the re-splashing of the caught foreign matter and the clogging due to it by including a foreign matter collecting body inside a vacuum tank, installing a washing liquid dispersing means in the upper part of the foreign matter collecting body, installing a gas inflow port and a gas discharge port in the upper wall and the lower wall of the vacuum tank across the foreign matter collecting body respectively, and further installing a washing liquid circulating means. CONSTITUTION:A foreign matter collecting body 4 is included inside a vacuum tank 1 and also a washing liquid spraying means 5 is installed above the foreign matter collecting body 4. In the upper part wall and the lower part wall of the vacuum tank 1 across the foreign matter collecting body 4, a gas discharge port 2' and a gas inflow port 2 are installed respectively. And also a circulating means 7, 8 for a washing liquid 6 is formed. The washing liquid 6 is a circulating liquid showing vapor pressure equal to or not more than that of a sealing liquid of a vacuum generator connected to the gas discharge port 2' of the vacuum tank 1. Further, a droplet catching means 12 for preventing droplets sprayed from a spraying means 5 from flowing in the vacuum generator is installed between the gas discharge port 2' and the spraying means 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for removing foreign substances from a gas containing foreign substances such as oligomers and low boiling point vapors through an exhaust port of a melt extruder for producing fibers, resins, films and the like. The present invention relates to a trap for vacuum piping.

[0002]

2. Description of the Related Art Generally, an extruder is used as an apparatus for producing fibers, resins, films and the like. As such an extruder, a vent type extruder is widely used, which molds while removing foreign substances such as low boiling substances generated inside. In this way, foreign matter generated in the extruder etc. flows into the vacuum generator,
It is generally practiced to provide a trap for removing foreign matter in the pipeline of the vacuum piping so that the foreign matter does not hinder the continuous operation of the vacuum generator. For example, Japanese Examined Patent Publication No. 3-31729 proposes a device for removing these foreign substances by filling a vacuum container with Raschig rings or pole rings as a collector.

However, the foreign substances trapped in these collectors are likely to become clay-like, and if left as they are, the collectors themselves will be clogged with these foreign substances. As a result, an increase in pressure loss is caused when the gas passes through the vacuum pipe trap, and the required degree of vacuum cannot be maintained.

[0004]

SUMMARY OF THE INVENTION In view of the problems described above, an object of the present invention is to solve the following problems.

That is, when a very high degree of vacuum is required as in a vent type extruder that is a manufacturing facility for fibers, resins, films, etc., the foreign substances accompanying exhaust will cause a large pressure loss in the vacuum piping trap. To provide a trap that does not do. Then, by using such a trap, it is possible to prevent the inflow of foreign matter into the vacuum generating device, prevent troubles due to mixing of foreign matter, and ensure that the vacuum generator and the trap can always maintain a high degree of vacuum. It is in.

[0006]

According to the present invention, there is provided a vacuum piping trap which simultaneously satisfies the following requirements A to E. A. A vacuum vessel, B. A foreign matter collector contained inside the vacuum container, C.I. A means for spraying the cleaning liquid, which is provided on the foreign matter collector, D. Circulation means for the cleaning liquid, and E. A gas inlet and a gas outlet respectively provided on the upper wall and the lower wall of the vacuum container with the foreign matter collector interposed therebetween.

Further, it is preferable that the cleaning liquid is a circulating liquid having a vapor pressure equal to or lower than that of the sealing liquid of the vacuum generator connected to the exhaust port of the vacuum container.

Further, a droplet capturing means for preventing the droplets of the cleaning liquid sprayed from the spraying means from flowing into the vacuum generator may be installed between the exhaust port of the vacuum container and the spraying means. preferable.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a front sectional view of a trap for vacuum piping, which illustrates the trap for vacuum piping of the present invention.

In the figure, reference numeral 1 is a vacuum container of a trap for a vacuum pipe, which illustrates the present invention, and a gas containing a foreign substance flows in from a gas inlet 2 thereof. This inflowing gas is
It passes through the foreign matter collector (4) made of a laminated wire net supported by the foreign matter collector support plate (3). At this time, the foreign matter contained in the inflow gas is captured by the foreign matter collector (4). The gas that has passed through the foreign matter collector (4) is exhausted from the exhaust port (2 ′), but the foreign matter trapped by the foreign matter collector (4) is washed off at the upper part of the foreign matter collector (4). There is provided a spray nozzle (5) which is a means for spraying the cleaning liquid. Thus, the gas inlet (2) and the exhaust outlet (2 ') are
They are attached to the upper part wall and the lower part wall of the vacuum container (1) with the foreign matter collector (4) interposed therebetween.

Further, the cleaning liquid is collected at the bottom of the vacuum container (1), is passed through the cleaning liquid circulation pipe (7) and is sent to the circulation pump (8), and the foreign matter collector ( Circulation is applied from above 4). At this time, the foreign matter removal filter (10) is on the conduit of the cleaning liquid circulation pipe (7) so that the cleaning liquid circulation pipe (7) is not clogged by the foreign substances trapped in the cleaning liquid and trouble does not occur in the circulation pump (8). It is installed in. When the filter (10) is clogged, the valve (9) is closed and the filter (10) is replaced. In the embodiment of FIG. 1, since only one system of the filter (10) is provided, it is necessary to stop the operation and replace the filter (10), but the filter (10) is connected in parallel. If two systems are installed and switched and used, it is possible to replace them without stopping the operation.

As described above, since the vacuum pipe trap of the present invention sprays the cleaning liquid, it is necessary that the cleaning liquid does not flow back to the vacuum generating device (not shown) to cause a trouble in the vacuum generating device. become. Therefore, above the vacuum container (1), a demister (12) which is a droplet collecting means for capturing the cleaning liquid is provided.
It is supported and installed in 1). As such a demister (12), a woven or non-woven fabric of metal fibers, ceramic fibers, synthetic resin fibers or the like can be used. Further, a cleaning liquid draining valve (13) for periodically exchanging the cleaning liquid is attached to the bottom of the vacuum container (1), and the cleaning liquid is drained from the liquid draining pipe (14) to the container (15). You can

As described above, in the present invention,
Since the cleaning liquid is used so that the collector (4) for capturing the foreign matter is not clogged, the cleaning liquid is preferably a circulating liquid having a vapor pressure equal to or lower than the sealing liquid of the vacuum generator.

FIG. 2 is a system diagram when the present invention is applied to a vent type extruder for producing polyester fibers.
In the figure, oligomers, ethylene glycol and the like generated by thermal decomposition of the polymer melted in the extruder (16) are discharged in a vapor state from the exhaust port (17) of the extruder. The discharged oligomer, ethylene glycol, and the like are discharged from the exhaust port (17), then pass through the exhaust pipe (18), and flow into the vacuum pipe trap (20). At this time, oligomers, ethylene glycol, etc. discharged in a vapor state from the exhaust port (17) of the extruder are discharged from the exhaust port (17) and then cooled so that they do not adhere to the exhaust pipe (18) and the like. The exhaust pipe (18) is preferably heated or kept warm.

In this way, the trap for vacuum piping (2
The gas containing the oligomer, ethylene glycol, etc., which has flown into the (0) is trapped in the vacuum pipe trap (2) as described above.
In 0), foreign substances such as ligomer and ethylene glycol are removed. Then, the gas from which the foreign matter has been removed is discharged from the vacuum generator (19) into the atmosphere.

The foreign matter collector of the vacuum pipe trap is preferably a laminated wire mesh, but it may be changed depending on the operating conditions such as the nature of the foreign matter to be exhausted, the required ultimate vacuum, and the exhaust flow rate. The optimum mesh size, number of laminated layers, laminated structure, material, etc. may be selected.

[0017]

As described above, according to the present invention, the foreign matter collector can be installed inside the vacuum container to remove the foreign matter contained in the exhaust gas, and the foreign matter can be transferred to the vacuum generator. Inflow can be prevented. In addition, by washing off the foreign matter adhering to the foreign matter collector with a cleaning liquid,
It is possible to prevent the captured foreign matter from being most scattered and flowing into the vacuum generating device. Moreover, it is possible to prevent foreign matter from adhering to the foreign matter collector and causing clogging, which increases pressure loss when passing gas through the foreign matter collector.

Furthermore, by selecting and using a cleaning liquid having the same properties as the sealing liquid of the vacuum generator, even if the cleaning liquid enters the vacuum generator, trouble does not occur in the vacuum generator. .

[Brief description of drawings]

FIG. 1 is a front cross-sectional view of a trap for vacuum piping, illustrating a trap for vacuum piping of the present invention.

FIG. 2 is a system diagram when the present invention is applied to a vent type extruder for producing polyester fibers.

[Explanation of symbols]

 1 Vacuum Container 2 Gas Inlet 2'Gas Outlet 4 Foreign Material Collector 5 Spray Nozzle 6 Cleaning Liquid 7 Cleaning Liquid Circulation Pipe 8 Circulation Pump 10 Filter 12 Demister 17 Exhaust Port 18 Exhaust Pipe 19 Vacuum Generator 20 Vacuum Trap

Claims (3)

[Claims] 1. A trap for vacuum piping which simultaneously satisfies the following requirements A to E: A. A vacuum vessel, B. A foreign matter collector contained inside the vacuum container, C.I. A means for spraying the cleaning liquid, which is provided on the foreign matter collector, D. Circulation means for the cleaning liquid, and E. A gas inlet and a gas outlet respectively provided on the upper wall and the lower wall of the vacuum container with the foreign matter collector interposed therebetween. 2. The vacuum pipe trap according to claim 1, wherein the cleaning liquid is a circulating liquid having a vapor pressure equal to or lower than that of a sealing liquid of a vacuum generator connected to an exhaust port of the vacuum container. 3. A droplet capturing means for preventing the droplets of the cleaning liquid sprayed from the spraying means from flowing into the vacuum generator, is installed between the exhaust port of the vacuum container and the spraying means. The trap for vacuum piping according to claim 1 or claim 2.