US467605A - Process of and apparatus for purifying gas - Google Patents

Description

INVENTlI/i I %-//%M 2 Sheets-Sheet 1. 'P. BREDEL.

PROCESS OF AND APPARATUS FOR PURIPYING GAS.

Patented Jan. 26, 1892.

(No Model.

ATTORNEY.

*(NQ Model.) H 2 Sheet-Sheet 2 n 1-". BREDEL. PROGESSQPAND APPARATUS FOR PURIFYING GAS. No. 467,605. Patented Jan. 26, 11892.

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WITNESSES: INVENTOI? v UNITED STATES PATENT OFFICE.

FREDERICK BREDEL, OF MILXVAUKEE, VISCONSIN.

PROCESS OF AND APPARATUS FOR PURIFY ING GAS.

SPECIFICATION forming part of Letters Patent No. 467,605, dated January 26, 1892.

Application filed July 25, 1891. Serial No. 400,725. (No model.)

To all whom it may concern.-

Be it known that I, FREDERICK BREDEL, a citizen of the United States, residing at Milwaukee,in the county of Milwaukee and State of Wisconsin, have invented certain new and useful Improvements in Cooling and Purifying Illuminating-Gas and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to an improved method of eliminating the impurities of the gas in such a way and at such a time of the process that the heavier illuminants cannot be absorbed by far. These impurities are tar, carbonic acid, sulphureted hydrogen, bisulphide of carbon, ammonia, and other sulphur compounds; The illuminants are propene or propylene, butene or butylene, &c., and benzol and naphthaline vapors, which latter give the gas a great illuminating power, but which are readily absorbed by tar as soon as the temperature of the tar falls below 95 Fahrenheit. This new process and statementmoves the tar in such a way that the gases cannot come in contact with the tar-wetted surfaces when the cooling and purifying process proper begins.

Having now given a general outline of the process, I will now commence to describe same.

On the annexed sheets of drawings the apparatuses are shown in different sections. Figure 1 is a side view, and Fig. 2 a plan, of the apparatus.

Same figures always have reference to the same apparatus or part of apparatus.

A is a washer, which will hereinafter be called the cooling-Washer B, the compensator; C, the ammonia-extractor; D, the cooler; E, the pump, and F the storage tank. The cooling-washer A and ammonia-extractor C are apparatuses of the style known as immersion-washers, and similar to the one on which Letters Patent were granted, under No. 380,040, to Mr. Aug. Kloenne, of Dortmund, Germany, under date of March 27,1888. The

is a surface condenseran apparatus similar to one for cooling and condensing anhydrous ammonia-vapors used in ice and cold-storage factories. Pump E is a pump specially constructed for pumping ammoniacal liquor or gas-water. Storage-tank F is an ordinary stor age-tank, into which the cool ammoniacal liquor is pumped. All the pipes and valves shown on the different plans are so arranged that the gas and ammoniacal liquor can be conveyed from one apparatus to the other with the necessary amount of by-pass valves to enable the by-passing and cleaning of one apparatus while the others are in use, and which will readily be understood by anybody familiar with the manufacture of gas.

I will now commence to describe the process. The gas, after it has been manufactured in the retorts or producer and having passed the exhausters, passes a friction or air or water surface condenser, or both or all three apparatuses, which are not shown in this plan; but it is not absolutely necessary to use one of these latter three apparatuses as long as the gas reaches the inlet G at a temperature of from to 100 Fahrenheit, preferably at from to 100 Fahrenheit, and as long as the mechanical impurities-such as coke-dust, heavy pitch, ate-have been removed, which can be done by either one of the aforesaid condensers or by the necessary length of gas-mains, as the gas will deposit all these impurities in a very short time by passing through conduits. From G the gas enters into the cooling-washer A in its bottom section A, where it immediately has to plunge through ammoniacal liquor, whereby part of the tar drops into the liquor without having a chance to absorb any of the heavy hydrocarbons mentioned'in my general explanation. The temperature of the gas is thereby lowered also. The gas then passes consecutively into the sections A A A A, where it loses all its tar, and, as said before, all the carbonic acid and as much sulphur as the ammoniacal liquor, which enters atH and which contains a great amount of caustic ammo'nia, is able to absorb and transform into carbonates and bicarbonatcs of ammonium and sulphates and bisulphites of ammonium. The gas in the meantime has given .up part of its heat to the ammoniacal liquor and leaves the cooling-washer at I at a temperature of from to 7 0, and is absolutely free of tar, which it generally is already after passing section A or A The sectionsin the cooling-Washer are not limited to five, but can be more or less. The gas passes from I through the pipes, following direction of arrows K K K K and enters the compensator B. The gas there is kept at an even temperature of 60 Fahrenheit, and this compensator has only the duty to fulfill of keeping the gas as near as possible to a steady temperature of 60, which otherwise would not be possible, as the flow of ammoniacal liquor which enters at H is nearly constant, while the quantityof gas manufactured at differentperiods during a twenty-four-hours run is always variable. For economys sake this compensator might be omitted, but it is advisable not to. The gas leaves the compensator at L, follows the direction of arrows M M M M M andenters the ammonia-extractor-at N and passes the different sections 0' 0 0 C C of said ammonia-extractor O, consecutively, and leaves the extractor at 0 free of ammonia. This apparatusis also not limited to five compartments, but might-consist of more or less.

To extract the ammonia, clear water, as free as possible of lime, is admitted at P. This water flows from section to section in the way described in the aforesaid patent, No. 380,040, till it'lea'ves the ammonia-extractor G at' R. It is then thoroughly charged with the ammonia originally contained in the gas, and partly with sulphates of ammonium. From B it flows in thedirection of arrow Q and enters the'coolin'g-washer A at I-Ltogether'with other ammoniacal liquor, coming from storage-tank F through pipes S. It goes then from section to section, as described in Patent No. 380,040, till it leaves the first section A of cooling-washer A at T. The water has naturally taken up partof the heat originally contained in the gas. At T it goes into a tar and light-oil separator U, where the tar and light oil are separated fromthe liquor and flow through Z and Z to the tar-well, while the ammoniacal liquor'leaves the separatorU and goes through V and pipe V and enters the cooler D at V and passing through the pipes Viwhich are continually cooled by cold water, it is cooled down to between 60 and Fahrenheit. After the ammoniacal liquor leaves the cooler at V it goes into distributing tank W, where a quantity of ammoniacal liquor equal to a quantity of clear water admitted at P is discharged at W into the ammonia-well, and the balance passes through pipe W- -into pump E, and-is then forced through pipe XV into storage-tank F and repeats the process. The position of pump E may be at option either ahead of or after cooler D. Also tank W may be ahead of cooler D, at option.

Instead of using only one cooling-washer A, it might under certain conditions be advisable to use two, either together or consecutively. It is not necessary to use a coolingwasher A or ammonia-extractor O of the construction shown and described in Letters Patent No. 380,040, for any good plunger or immersion washer might be substituted for either of them, and if a rotating Washer should be available such a one may be substituted for ammonia-extractor C. For compensator B any multitubular condenser having sufficient water capacity might be substituted. For cooler A any water cooler might be substituted. If it is deemed advisable to remove all the sulphur-impuritiesout 0f the gas with this purifying-machine, it is necessary that there should be enough-am monia in the gas to chemically bind all the carbonic-acid and sulphur compounds contained in the gas. This condition is scarcely ever fulfilled. To increase the capacityofth s purifying-machine itisnecessary to makemore austic ammonia available to do this work. This is done by letting all-the ammoniacal liquor which comes from the hydraulic main and condensation ahead of this machine, which liquor contains a large amount of caustic ainmonia, enter either by gravityor bypumprng it into any of the compartments of th'ewashers A or 0, preferably in compartments C C or A It naturally must not-'be-introduced 1n O or 0 This introduction can bedone in anyway which might suggest itself, or as shown on plan 1 at'P and H; butthis amount of caustic ammonia will generally not be sufficient to freethe gas of all its-impurities; as it forms-carbon and sulphur-compounds-of ammonia. If, therefore, the complete purification of the gas by this apparatusis deemed necessary and advisable, instead of, as :it is now generally done, passing the gas through iron-oxide orlime purifiers after leaving this apparatus, an additional quantity of caustic ammonia in the shapeof either aqua-ammonia in its crude or purified stateor in the shape of anhydrous ammonia, the latter-preferable in gas form, has to be procured.

As there are different processes'well known to everybody conversed in the art, I will not try to explain the processes of manufacturing either aqua or anhydrous ammonia here, but only the way they have to be used. If aqua-ammonia is used, it is preferable to use a weak solution not containing more than from ten to eighteen per cent. of ammonia,

(NH,,,) as otherwise the loss by evaporation would be too great. This solution could best be introduced in the necessary quantities-at either 0, A or A If'anhydrous or an ammonia gas is used, then it should best-be mixed with the gas before it enters the coolingwasher A. The quantity of ammonia re quired for the complete purification of the gas would differ according to the impurities originally contained in the gas manufactured, as all the time sufficient ammonia has to be present to absorb by neutralization or chemical combination the impurities of the crude gas.

I am perfectly aware that plunger-washers have been used before, but do not know, to my best knowledge and belief, that they have ever been used for cooling the gas, by which is meant to bring the gas from a high temperature to such a temperature where the rational elimination of ammonia is possible. This work has up to now been done by what is known as air or water condensers, which offered the passing gas large tar-wetted surfaces, which tar being at a lower temperature than the passing gas readily absorbs the heaviest of the olefiant gases and the benzol and naphthaline vapors, which latter are the best illuminants. Furthermore, by so chilling the gas in the presence of tar the condensation into and formation of naphthaline crystals, commonly known as naphthaline, is made possible, while, as is done in my apparatus and process, the formation of such naphthaline crystals by cooling the gas through the medium of direct contact with more or less caustic ammoniacal liqnorbecomes impossible, and the naphthaline or benzol vapors remain as a more or less permanent vapor in the gas.

In the following claims the cooling of the gas is always understood to be the process of bringing the gas safely over its critical cooling moments, which lie for the formation of naphthaline crystals below 95 Fahrenheit in the presence of tar, and which formation is impossible when all the tar is removed by immersion of the gas in more or less caustic ammoniacal liquor before it reaches the temperature of 74 Fahrenheit.

Having thus described the process and dif-. ferent apparatuses used, I claim as new and as my invention- 1. The process of cooling and completely or partly purifying coal or carbureted watergas, which consists in passing the gas through an immersion or plunger washer while it is yet at a temperature which would prevent the partial condensation of benzol and naphthaline vapors or the absorption of same by tar, cooling the gas gradually by immersion in and passing through ammoniacal liquor, and then passing it through an ammonia-extractor of any form, substantially as and for the purpose specified.

2. The combination of a cooling-washer A, a compensator B, an ammonia-extractor C, cooler D, pump E, with storage-tank F, substantially as and for the purpose specified.

In testimony whereof I affix my signature in presence of two witnesses.

FREDERICK BREDEL.

\Vitnesses:

THEo. KRAUSE, FRANK M. HOYT.

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