US1937460A

US1937460A - Process for removing naphthalene from gases

Info

Publication number: US1937460A
Application number: US516821A
Authority: US
Inventors: Muhlendyck Wilhelm
Original assignee: Individual
Current assignee: Individual
Priority date: 1930-02-19
Filing date: 1931-02-18
Publication date: 1933-11-28
Anticipated expiration: 1950-11-28

Description

Nov. 28, 1933. w. MUHLENDYCK 1,937,460

PROCESS FOR REMOVING NAPHTHALENE FROM GASES Filed Feb. 18, 1931 Patented Nov. 28, 1933 UNITED STATES PATENT OFFICE Wilhelm Miihlendyck, Dortmund, Germany Application February 18, 1931, Serial No. 516,821, and in Germany February 19, 1930 7 Claims.

This invention relates to a process for removing naphthalene from gases.

The gas produced during the dry distillation or gasification of fuels contains naphthalene and cannot be completely freed therefrom by the ordinary oil washing processes, because considerable quantities of naphthalene invariably remain in the gas. This residual naphthalene contained in the gas is always a source of difficulty when 10 conveying the gas in tubular conduits and especially when the gas is to be forced through the pipes under pressure for supplying places at a distance. Serious diificulties are occasioned by the constrictions or stoppings up which are produced by deposition of the naphthalene in the cooler portions of the pipes, and especially in circuits for conveying the gas to any distance.

Attempts have therefore been made to effect the complete removal of the naphthalene from the gas. To this end it has been attempted to remove the naphthalene by adsorption agents of various kinds; and it also has been thought that the naphthalene could be removed by super-cooling the gas. However, all these measures have hitherto not led to satisfactory results. Separating out the naphthalene by washing, by irrigation or by spraying with water has in a similar manner led to no satisfactory result.

It has now been found in accordance with the 80 present invention, that it is possible to effect the complete removal of naphthalene from the gas by means of water, by spraying the water in a finely divided state into the current of gas, so that a perfect mist formation is obtained. The last traces of naphthalene can be removed from the gas by virtue of this precaution. It is important in this connection to cause the fine mist to occupy the whole cross section of the washing pipe or tower. The water, the flow of which can be regulated by a pressure release valve, flows away and entrains the naphthalene, which latter is collected in a separate container preferably provided with one or more thin layers of sand, quartz or the like. The water thus freed from naphthalene can be re-employed for further washing operations.

It has also been observed that it is not necessary to maintain low temperatures of 15 C. or slightly above during the process:-Thus, when the temperature rises to C., an equally effective washing effect has been obtained. It has thus been possible by means of the present invention, not only to effect the completeremoval of naphthalene from the gas with the cheapest of all washing agents. but to bring about this action with very small quantities of water, since after removing the naphthalene from the water by a simple process of purification the said water is capable of repeated application. Moreover .the fact that the opera- 0 tion is independent of the maintenance of definite temperature limits is conducive of assuring an economical result.

In order to carry out the process a simple washing device is employed in combination with 5. nozzles by means of which a very fine mist formation can be obtained. The washing tower or the washing tube is advantageously chosen in such a manner that the washing process may also be carried out under pressure. If the wash- 7o ing process is to be carried out under pressure then the dimensions of the washing'vessel may be made considerably smaller.

Under some circumstances it is also of advantage to remove the bulk of the naphthalene in a 7 known manner with washing oils and to dispose of the residual remaining quantity by means of the finely divided spray of water. With this modification of the process it is possible to operate with a very small quantity of water and further to reduce the erecting costs of the plant as well as the operating costs.

The process according to the invention is carried out in a washing plant which is shown diagrammatically in the annexed drawing in which Figure 1 is a vertical section and Figure 2 a top plan view of Figure 1. This washing plant comprises three

washing towers

1, 1a and 1b which are connected in series, the

requisite filters

2, 22 and 32 by means of which the water used as a puri- .90 fying agent is freed from the naphthalene and delivered to a collecting tank 3. The naphthalene containing gas enters at A, passes through the three washing towers by way of conduits '7 in the direction of the arrows and through regulating valve 8is discharged at B completely freed from naphthalene. The valve 8a serves for re moving liquid-constituents. The washing out of the naphthalene from the gas is effected by a fine water spray (indicated by small dots) covering the entire cross sectional area of the

washing towers

1, 1a and 1b which are sprayed through the nozzles fixed to the rising

pipe

5 and 5a. These nozzles are alternately arranged on both sides in such a way as to prevent the intersection of the spraying cones and to render impossible the formation of drops. The water which is present in the atomized state is loaded with the naphthalene of the gas and collects on the bottom of the washing towers whence it flows off through the valves 8a and the water outlet .pipes 6 into the filters 2 and from there into the collecting tank '3 subdivided into three compartments. The

filters

2, 22 and 32 contain layers 2b of quartz or regulating the gas outlet. -9 are water gauges.

indicating the level of the water that has collected on the bottom of each of the washing towers. Numeral 10 designates a gas outlet. cock of the pinch-cock type and is normally closed. Numerals 11 designates baflle plates. For attending to the various valves, etc., a diagrammatically drawn platform 12 is provided which may be reached bymeans or the stairs 13.

I claim:-- a

1. A process for removing naphthalene from gases Whichcomprises washing outv the naphthalene by means of a fine mist-dike spray of water at a temperature between 15 and C., passing the water through filter beds tofree it from naphthalene'andreturning it to the process.

2. A process'ior removing naphthalene from gases which comprises washing out the naph-- thalene by means of a fine mist-like spray of water at a temperature between. 15 and 40 0.,

passing the water through beds of sand to free it from naphthalene and returning it to the process.

water, passing the water through beds of quartz to free'it from naphthalene and returning it to the process. 4

4. A process for removing naphthalene from.

gases which comprises treating the gases with washingoils, washing out the residual naphthalene by means of a fine mist-like spray of water,

passing the water through filter beds to free it from naphthalene and returning it to the process.

*5. A process for removing naphthalene from gases which comprises treating the gases with washing oils, washing out the residual naphthalene by means of a fine mist-like spray of water, passing the water through beds of sand to free it from naphthalene and returning it to the process. v

6. A process forremoving naphthalene from gases which comprises treatingthe gases with washing oils, washing out the residual naphthalene by means of a fine mist-like spray of water, passing the water through beds of quartz to free it from naphthalene and returning it to the process. I

7. A process for removing naphthalene from gases which comprises washing out the naphthalene by means of a fine mistlike spray or water.

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