US1912393A - Distillation of tar, etc. - Google Patents

Description

June 6, 1933. F. OSBORNE 1,912,393

DISTILLATION OF TAR, ETC

Filed Fb'. 26, 192'! 2 Sheets-Sheet l COKE OVEN BATTERY CON DEN 5 ER CONDENSER JMM BY PMMMW ATTORNEYS June 6, RNE I DISTILLATION OF TAR, ETC

Filed Feb. 26, 1927 2 Sheets-Sheet 2 Fig: cl

Li-IL 1m 3 E 5 l r l 24 COKE OVEN CONDENSER. J

g INVENTOR com; ovgu M%MM ATTORNEYS Patented June 6, 1933 UNITED STATES PATENT OFFICE,

' FRED OSBOKNE, F BI IIRMINGHAM, ALABAMA, ASSIGNOR TO THE BARRETT COMPANY,

OF NEW YORK N. "1., A CORPORATION OF NEW JERSEY DISTILLATION OF TAR, ETC.

Application filed February 26, 1927.

'This invention relates to improvements in the distillation of tar and the production I particularly, the invention relates to improvements 1n the distillation of coal tar and the production of pitches at coal distillation plants, such as by-product coke oven, gas oven or gas'retort plants.

In the ordinary operation of by-product coke ovens the gases produced by the coking operation pass from the individual ovens through individual uptake pipes and goosenecks to a collector main or mains common to a battery of ovens. The coke oven gases leaving the ovens at a high temperature are cooled to separate tar constituents therefrom, the tar constituents being separated partly in the collector mains and partly in subsequent condensers.

Coal tar produced at by-product coke ovens is commonly shipped or conveyed to tar distillation plants where it is subjected to distillation for the recovery of coal tar distillates and the production of pitches as residues of the distillation.

The present invention provides an im proved process of and apparatus for distillation of tar for the production of pitch at a coke oven plant, and with recovery of the volatile oils from the distillation along with the lighter tars and oils from the coke oven plant. More particularly, the invention relates to improvements in the distillation of tar with hot coke oven gases in modified uptake pipes located between the coke oven and the collector main.

When tar is distilled by atomizing or spraying it into the hot coke oven gases as they pass through the uptake pipes on their way from the coke ovens to the collector main, the volatile oils driven off from the tar pass with the gases into the collector main, while the pitch or residue from the distillation of the tar can be collected and separately tillation. If the distillation of the tar is carried to the point where heavy pitch is produced, a correspondingly increased recovered as a product of the disv Serial No. 171,154.

amount of heavy oils are driven off from the tar during the distillation and pass over with the gases into the collector main. These heavy oils tend to separate out with the tar in the collector main, and if the resulting tar is returned for further distillation to produce pitch therefrom, the heavy oils are again distilled and returned to the collector main and tend to increase in amount as they are repeatedly distilled by the hot coke oven gases and condensed in the collector main,

The improved method of operation of the present invention enables this objection to be overcome, and enables the oils or distillates driven off during the distillation of tar to be recovered in the ordinary by-product recovery system of the coke oven plant without the accumulation of heavy products of the distillation in the tar to be redistilled.

The present invention relates particularly to operations in which tar containing high According to the present invention, I pro- I vide separate collecting means, such as a separate collector main, for the modified uptake pipes which are employed for the distillation of tar, so that the distillates from such distillation do not enter the ordinary collector main, but are kept separate in the separate collector main; and I pass the gases and vapors from such separate main to the condensing system connected with the ordinary cross-over inain of the battery. In this way, I keep separate the heavy oils distilled from the tar, and recover them separately either in the separate collector main, or pass them over to the condensers of the battery and condense and recover them in admixture with the lighter tar and oils from the normal operation of the battery.

From the standpoint of apparatus or equipment, I provide, in addition to the ordinary collector main and condensing system of the battery, a separate short collector main or mains and I connect the uptake pipes which are modified to permit tar distillation therein, with the separate short collector main so that the gases and vapors resulting from the distillation are collected therein; and I then pass the gases and vapors from the separate main to the direct or indirect coolers forming part of the main condensing system of the battery. The modified uptake pipes are also advantageously connected with the usual collector main, and provided with valves for enabling the gases from the uptake pipes to be discharged either into the ordinary main, when not employed for distillation, or into the separate collector main, when employed for such distillation.

The distillation of the tar, in the modified uptake pipes, is effected by the heat contained in the hot coke oven gases passing upwardly therethrough, for example, by atomizing or spraying the tar or otherwise bringing it into intimate contact with the hot coke oven gases immediately after they leave the coke ovens, or at least while they are at a temperature high enough to accomplish the desired distillation. This distillation of the tar by the hot coke oven gases gives pitch or a heavy residue, and increases the vapor content of the gases by the Vapors driven off from the tar during the distilla-r tion. Some of the heavier constituents of the gas are removed therefrom by the scrubbing action of the tar spray and are added to the pitch residue, while the remainder of the condensable constituents of the hot coke oven gases pass with the added vapors from the distillation to the separate collector main.

The number of ovens provided with the modified uptake pipes and employed for the distillation of tar, can be varied. A few only of these modified uptake pipes are suffi- .cient for distilling the tar from an entire battery. However, by providing connections between the modified uptake pipes and the ordinary collector main, as well as with the separate collector main, it is possible to provide a considerable number of the modified uptake pipes and to use as many or as few of them as desired for tar distillation. Those which are not so employed can be opened to the ordinary collector main, while those which are employed for tar distillation can be opened to the separate collector main.

The separate collector main, which collects the gases and vapors from the distillation, may be provided with tar or ammonia liquor spray to assist in condensing the heavier constituents, and the tar or oil thus condensed can be drawn oil from the separate collector main as one of the products of the process. The gases and vapors that remain after such preliminary condensation are then passed over to the ordinary coolers or condensers to which the gases and vapors from the ordinary collector main pass for the recovery of light tars and oils therefrom. In this way, a separate condensing system is not necessary, while the. heavier oils from the distillation of the tar are prevented from entering the ordinary collector main and becoming admixed with the heavy tar separated therein.

From the standpoint of battery operation, the greater part of the battery may be operated in the ordinary way with discharge of the gases from the ovens into the common collector main which may be provided with tar and ammonia liquor sprays, and in which the heavier tar will be thrown down and separated as a heavy tar product. The remaining gases and vapors then pass over through the cross-over main to the coolers or condensers which may be of the direct or indirect type and in which the gases are further cooled to separate the greater part of the remaining condensable constituents therefrom.

That part of the battery which is provided with the modified uptake pipe leading to a separate collector main, is operated with tar sprays to effect distillation of the tar by the hot coke oven gases in the modified uptake pipes and the resulting admixed gases and vapors then pass to the separate collector main where some of the heavier constituents may be condensed and separated, and the remaining gaseous and vapor mixture then passes to the condensers or coolers above mentioned.

The tar which is distilled according to the present process, may be tar produced at the same coal carbonizing plant at which it is distilled, or it may be tar from another coal carbonizing or other plant. It may be a heavy tar, a light tar, or tar of widely varying properties. It may be a heavy tar containing only part of the oils from the coal distillation, or it may contain all or practically all of the condensable oils, as where all of the tar constituents are normally collected or condensed together. The manner in which the tar is brought into direct contact with the hot vapors can be varied. A suitable atomizing or spray nozzle, to which the preheated and thinly fluid tar is supplied under a sufiicient pressure to bring about atomizing or spraying and resulting intimate contact of the tar with the hot gases, can be located in the upper part of the modified uptake pipe to bring the tar into intimate contact with the hot gases.

A single tar spray can be used in each of the individual uptake pipes, or a plurality or series of such sprays, and the rate at which the tar is sprayed, as well as its temperature, can be regulated and controlled to obtain a greater or less degree of distillation of the tar andthe production of distillates of desired characteristics and of harder or softer pitches or pitch-like products.

The gases esca ing from the top of a coke oven are at a hi temperature, e. g., around 600 to 700 or in some cases much hi her. The temperature of these gases is su ciently high so that effective distillation of the tar can be accomplished by an intimate and regulated spray of the tar into the hot gases. By employing the gases at practically top-of-oven temperature their maximum heating and distilling effect is utilized. The amount of tar and the intimacy and time of contact of theparticles of the tar spray with the gases, and the nature and amount of oil distilled therefrom, can be varied. I

By regulation of the rate and type of tar spray and its temperature of preheating, and by redistillation when necessary, it is possible to regulate the hardness of the pitches produced, and produce softer or harder pitches, as desired, and oils of different characteristics may be formed. The further distillation of the pitch first produced to recover additional oil therefrom, can be carried out in the same uptake pipe still, or it may be subjected to further dis-' tillation in another uptake pipe still. The invention is particularly advantageous in that the distillation of the tar or pitch effects the vaporization of some of the heavier oils which would normally be thrown down in the ordinary collector main as a part of the heavy tar andwhich, if so thrown down, would be returned and redistilled repeatedly with resulting accumulation of the amount of these heavy oils in the heavy tar. By separately collecting these heavy oil vapors in the separate collector main, they can then be passed over to the ordinary condensing system and kept out of the heavy tar. The invention thus provides a means for distilling the heavy tar and separating heavy oils therefrom and recovering these heavy oils in the ordinary condensing system of the coke. oven plant.

The invention will be further illustrated by the following more detailed description taken together with the accompanying drawings, which show apparatus embodying the invention and adapted for the practice of the process of the invention, but it is intended and will be understood that the invention is illustrated thereby but not limited thereto. I

In the accompanying drawings,

Fig. 1 shows a plan view of art of a coke oven battery modified to emb y the present invention and to permit operation of. the process of the invention,

Fig. 2, is a view in elevation showing part of one end of the battery,

Fig. 3 is an enlarged sectional view through the modified uptake pipes and collector main, and,

' Fig. 4 shows one form of modified uptake ipes.

p The invention is of more or less general application to different types and construction of by-product coke ovens such as Semet-Solvay ovens, Koppers ovens, etc., but will be more particularly described and illustrated in connection with by-product coke ovens of the Semet-Solvay type.

In the drawings, the coke oven is illustrated conventionally at 1 and has the usual gas outlet 2 for the escape of the hot coke oven gases. The outlet pipe 3 is seated in a suitable seal over the gas outlet 2 and con.- nects at its upper end with the lower end of the casing 4. The upper end of the casing 4 connects with the uptake L 5 which leads to the ordinary collector main 6 and to the separate collector main 7, valves 8 and 9 being provided for connecting the uptake L with one or the other of these mains as desired.

The casing 4 is enlarged to provide a space around the inner pipe member 10 which extends upwardly into the enlarged casing 4. The lower ends of the pipe 10 and the casing 4 are preferably integral or otherwise arranged to provide an annular receptacle for the collection of the pitch or residue from the distillation.

Located within the casing 4 and above the end of the pipe 10 is a baflie or hood 11 and above this is a spray head 12 connected with a pipe 13 for spraying tar to be distilled.

An outlet 14 for pitch or residue is located.

at the bottom of the enlarged casing 4 for discharging the pitch or--residue from the annular space at the bottom of the casing, to a tank or other receptacle 14'. The casing 4 is attached at its lower end to the outlet pipe 3 which in turn is sealed in the roof structure of the ovens.

.the casing.

The connection from the uptake pipe stills to the collector mains may be provided with a spray 19 for cooling or assisting in cooling condensable constituents of the gas and for spraying the valves 8 and 9. Ad ditional spray nozzles 20 may also be provided in the ordinary collector main 6 and other sprays 21 in a separate collector main 7. Ammonia liquor can be used in such sprays, or tar, or a mixture of liquor and tar.

The coke oven battery illustrated in Fig. 1 has the ordinary pipes 22 connected with the usual collector main 6. The usual crossover mainis indicated at 23, leading to the coolers or condensers 24 and 25 connected to decanter 26. The exhauster for drawing the gases through the system is indicated at 27. This part of the system comprising the uptake pipes 22, collector main 6, cross-over main 23, coolers, etc., is the ordinary byproduct coke oven system.

The tar collected in the collector main and cross-over main is shown as running to a tar collecting tank 28 in which the tar separates from the ammonia liquor and this tar in turn is shown as leading to a dehydrator 29 for completely freeing the tar from water or preheating it for distillation. The dehydrator may be of any suitable construction. The dehydrated and preheated tar is then pumped by the pump 30 through the tar supply line 13 to the spray nozzles 12. Undehydrated tar may be used if desired. It is, however, advantageous to the spraying operation that the tar be preheated to the extent that it is in a thinly fluid condition as it is delivered to the sprays.

The separate collector main has a discharge pipe 33 leading to a decanter 34 for collecting the heavy condensates separated in this separate collector main. The uncondensed vapors and admixed gases pass from this separate collector main through a separate cross-over main 32 to the condensers or coolers 24 or 25 above described. The piping arrangement is such that the gases and vapors from the separate collector main may pass either to the condenser or cooler 24 or to the condenser or cooler 25 or through the two condensers or coolers in series, so that the products separated out from the gases and vapors may be admixed with one or the other of the products from these separate condensers or coolers, where these products are kept separate. A pipe 35 controlled by a valve 36 permits delivery of gases and vapors from the pipe 32 directly to the cross-over main 23 when such operation is desired.

The products thus separated and recovered in the condensers and coolers 24 and 25 will be composite products, being made up in part from products condensed from the main coke oven gases of the battery and in part from the distillates from the separate distilling system. The relative proportions of these separate condensed constituents can be regulated by regulating the extent to which the admixed gases and vapors are cooled and scrubbed in the separate collector main, and by regulating the condenser or cooler into which the separate .of the uptake stills will gases and vapors pass for further condensation. A further regulation is possible by increasing or decreasing the amount of tar distilled, or the extent to which the tar is distilled. When the amount of tar to be distilled is increased, a larger number of the uptake pipe stills can be employed for the istillation and connected with the separate collector main. When the amount of tar to be distilled is decreased, a smaller number he required. In the apparatus illustrated, a greater or smaller number of the u take pipes can be employed for the distil ation and connected to the separate collector main, while those which are not so employed can be connected with the ordinary collector main, thus keeping separate the gases employed for the distillation from those which are not so employed.

Considering the operation of a single coke oven battery, the invention makes possible the distilling of all of the heavy tar collected in the collector and cross-over mains and the driving off and recovery therefrom of volatile oils and the production of pitch, the volatile oils being carried over and collected in the ordinary condensing system of the battery. In this way, all of the heavy tar is converted into pitch and distillate oils, and all of the distillate oils are separately recovered along with the lighter tars and oils from the normal operation of the battery.

While I have described and illustrated a particular type and construction of uptake pipe still, and a particular arrangement and size of separate collector mains, and a particular arrangement of connections with the ordinary condensing system, it will be evident that the invention in its. broader aspects can be carried out in the apparatus .of

other constructions and that variations and modifications can be made therein without departing from the spirit and scope of the invention.

I claim:

1. The improvement in the operation of the by-product recovery system of a coal distillation .plant which comprises collecting coal distillation gases from part of a battery and removing heavier tar constituents therefrom, distilling tar by bringing it into contact with hot coal distillation gases evolved from another part of the battery to distill volatile oils from the tar and produce pitch therefrom, collecting the resulting gases and vapors separately from the gases from the mixture with condensates from the li hter constituents of the gases first mentione 2. The improvement in the operation of the by-product recovery system of a coke oven plant which comprises collecting coke oven gases from part of a coke oven battery and recovering heavier tar constituents therefrom, distilling coal tar to pitch by bringing it into contact with hot coke oven gases evolved from another part of the battery to distill volatile oils from the tar and produce a gas mixture containing vapors of heavier condensable constituents and lighter condensable constituents distilled from the tar, recovering the heavier condensable constituents from said gas mixture apart from the aforementioned recovery of heavier tar constituents from coke oven gases, and recovering lighter constituents from said gas mixture together with lighter constituents from the first mentioned coke oven gases by combining the gases with the gas mixture, and cooling the combined gases.

3. The improvement in the operation of the by-product recovery system of a coke oven plant, which comprises cooling coke oven gases from part of a coke oven battery to separate heavier tar constituents therefrom, recovering the heavier tar constituents and distilling them by bringing them into contact with hot coke oven gases evolved from another part of the battery thereby distilling the tar to ,pitch and forming'a gas mixture containing volatile oils distilled from the tar, separately collecting the resulting gas mixture and combining it with said coke oven gases from which heavier tar constituents have been separated, and cooling the combined gases to separate condensable oils therefrom.

4. The improvement in the operation of the by-product recovery system of a coal distillation plant, which comprises collecting coal distillation gases from part of a battery and removing heavier tar constituents therefrom, distilling tar by bringing it into contact with hot coal distillation gases evolved from another part of the battery to distill volatile oils from the tar, cooling these gases to remove heavier condensable constituents, blending these gases with the first-named gases after said removal of heavier tar constituents and cooling the blended gases to recover lighter condensable constituents.

In testimony whereof I afiix my signature.

FRED OSBORNE.

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