DE3205536A1 - DEVICE FOR WASHING OUT DUST PARTICLES FROM EXHAUST GAS FROM A NUCLEAR TECHNICAL PLANT - Google Patents

Description

Device for washing out dust particles from the exhaust gases of a nuclear plant

The liquid highly radioactive during glazing Waste gases generated in the melting furnace must be kept from entrained dust particles be released because they are highly radioactive. It is possible to use a gas scrubber for this purpose, that from a washing column or a tower washer consists. There is a collecting vessel below the gas washer arranged for the washing liquid. the Washing liquid is applied to the head of the gas scrubber and runs down the gas scrubber from above and drips into the collecting vessel. The furnace exhaust is introduced into the gas scrubber from below and flows through it from bottom to top in countercurrent to the. Washing liquid. As it flows through the scrubber, the largest toilet becomes

2'0 d ~ * r dust part i.kfi.1 absorbed by the washing liquid.

The contaminated washing liquid flows into the collecting vessel. From this receptacle it becomes like -25. returned to: -n head of scrubber. This Circulation of the washing liquid was therefore provided to prevent the accumulation of radioactive secondary waste to minimize.

To bring the scrubbing liquid back to the head of the scrubber So-called airlift conveyor systems have proven their worth. At these Alrlift conveyor facilities the conveying movement is achieved by bubbling air into a column of liquid. The promotion of the washing liquid means

Airlift is safer than with a pump because the Airlift has no moving parts. Through this there is no need to replace a pump, which might otherwise be necessary. There is no secondary waste due to a contaminated pump and the possible radiation exposure of the personnel during the pump change not applicable.

If now the washing liquid circulating in the circuit is heavily soiled after a certain time and is sucked in with the airlift and into the gas scrubber the airlift or the gas scrubber can become clogged. At least but becomes the decontamination factor of the gas scrubber decreased. It has therefore hitherto been necessary to replace the washing liquid at shorter intervals.

The invention is based on the object of creating a device for washing out dust particles from the exhaust gas of a nuclear plant, at d ¹ · .; die im Kre. '.., l.'iuf a ^ :; uhr Le washing liquid eirir * has a significantly longer service life.

According to the invention, the object is achieved by the characteristics of claim 1 mentioned features solved.

The dirty washing liquid flowing from the gas scrubber into the collecting vessel is used for cleaning subjected to sedimentation and decantation.

The lower partition forms an overflow weir for the Washing liquid, while the upper partition wall on the one hand for the exhaust gas separation of the lower one Dividing wall formed two chambers serves and on the other hand by their submersion below the level the first chamber contributes to the retention of dust components in the first chamber.

With the invention, the dirty washing liquid subjected to a coarse cleaning, which extends the service life of the washing liquid ...

This intermediate cleaning of the washing liquid in the sedimentation and decantation stage according to the invention causes less pollution of the gas scrubber and thus achieves a higher level Decontamination factor of the wet dust extractor. A blockage "of the gas scrubber or the Airlif't conveyor direction by entrained with washing liquid Dust is effectively prevented.

An advantageous embodiment of the invention is . indicated in the characterizing part of claim 2. By

In this configuration, the collecting vessel is divided into more than two chambers below the gas scrubber. Several sedimentation stages alternate with decantation stages.
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E-int-ä v / eitere vorte Lib -ir.tu i \ .u3q ^j otaltuny the Krf indurvj is disclosed by the features specified in the characterizing part of claim 3. The sediment that collects at the bottom of the chamber connected to the liquid inlet can thus be easily sucked off and returned to the pre-larjacje vessel for the highly radioactive waste.

An exemplary embodiment is explained in more detail below with the aid of the drawing.

The device for washing out dust particles from the exhaust gas of a melting furnace has a collecting vessel 1 which is surrounded by two transverse partition walls 2 and 3 is crossed. Through the lower,

The partition 2 attached to the bottom of the vessel divides the collecting vessel into two liquid chimneys 4 and 5. The upper partition 3 is attached to the housing cover and protrudes vertically into the collecting vessel 1 into the liquid chamber 4. The upper partition 3 is arranged at a distance from the partition 2 and protrudes beyond the end of the partition 2.

A washing column 6 is arranged vertically above the collecting vessel 1 and the lower end is above a pipe 10 is connected to the collecting vessel 1 in the region of the chamber 4 '. At the head of the washing column 6 the outlet line 7 for the cleaned exhaust gas and a feed line 8 for the washing liquid is attached. This feed line 8 is connected to an outlet 9 of the collecting vessel 1 at the bottom of the vessel in the area of the Chamber 5 connected.

In the connection line 11 between the supply line and the outlet 9 is a connection line 12 of a known ¹ Air "! L --- Li :: ■ ^; LL ^ r :: qeschaltot ..

The delivery line 13 of a further airlift device reaches to the bottom of the liquid chamber 4. 25

The collecting vessel 1 has an exhaust gas feed line 14 in the area of the Kamro-ar 4, which is at a height above the end of the partition 2 is arranged.

The operation of the device described above is as follows.

The contaminated flowing back from the washing column 6 WaschElussigko.it initially arrives in the first chamber 4. When the liquid level has reached the upper edge of the partition 2, flows

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the washing liquid over this upper edge of the Partition 2 and runs into the second chamber 5. The partition 2 forms an overflow weir for the Washing liquid. Dust particles can settle in the first chamber 4.

Through the partition 3, the chambers 4 and 5 separated from each other in terms of exhaust gas. Furthermore, the submersion of the partition 3 causes below the liquid level retention of lighter constituents floating on the solution in chamber 4. Next becomes a direct transition through .the submersion of dust particles falling over the partition 2 is prevented. ".

In the second chamber 5 is by means of the airlift conveyor 12 maintain a lower level than in the chamber 4 via the pipeline 11. The linaaro flow rate of the washing liquid in the transition from chamber 4 in K.M: '. R.r-r 5 itah nui-'Ti'v. ν'ί ck? s great Strömuiigsquer— cut relatively low. As a result, the sedimentation of the dust particles in chamber 4 is hardly disturbed. Thus, only a washing solution largely free of dust particles reaches chamber 5. She is going over the airlift conveying device 12 is conveyed back to the head of the washing column 6.

The sediment that accumulates at the bottom of chamber 4 from dust particles is periodically sucked off with the aid of the second Airlifc conveyor 13 and returned to the receptacle for the highly active waste. . . "

It is also possible to subdivide the washing liquid to increase the cleaning effect

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Collecting vessel 1 to carry out in more than two chambers. The division is made by dividing walls that are alternately attached from above and below achieved.

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1 Collecting vessel 2 Partition wall . 3 Trennv; and 4th Liquid chamber 5 Flüö aigke i hskammer β Washing column 7th Output line 8th Supply line 9 sequence 10 pipe 11 Connecting line 12th Connection 13th Delivery line 14th Exhaust pipe

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Claims (3)

Deutsche Gesellschaft Hannover, February 10th, 1982 for reprocessing VS / Gg / Hu von Kernbrennstoffen mbH ηη {fj Hamburger Allee 4 ΰά / J 3000 Hannover 1 Schutzansorüche 10 1. Device for washing out dust particles from the exhaust gas of a nuclear facility, in particular from the exhaust gas of a vitrification furnace for highly radioactive waste, with a vertical standing countercurrent washer and a collecting vessel arranged below for the washing liquid, whereby the washing liquid is circulated, characterized , that the collecting vessel (T) two at a lateral distance having partition walls (2, 3) arranged to one another and extending transversely through the collecting vessel, which have a lower height than the collecting vessel that the one adjacent to the washing liquid inlet The partition (3) is attached to the vessel lid and extends into the collecting vessel (1), that the partition (2) located at a distance behind it is attached to the bottom of the vessel, that the ends of the two partitions overlap somewhat and that the drain (9) of the washing liquid is arranged on the bottom of the vessel behind the lower partition (2). 2. Device according to claim 1, characterized in that that more than two partitions (2,3) are provided, which alternate on the vessel lid and on the vessel bottom are appropriate. 3. Device according to claim 1, characterized in that that a suction line (13) which can be acted upon at the bottom of the vessel in the one connected to the inlet and formed by the lower partition (2) in the collecting vessel (1) Chamber (4) ends.