BE366276A - - Google Patents

Description

       

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  "IMPROVEMENTS IN THE DISTILLATION OF TAR
AND SIMILAR MATERIALS "
This invention relates to the distillation of hydrocarbons such as tar, tarry oils, pitch, etc., and relates to an improved distillation process and apparatus.



   The process and apparatus according to the invention allow tar to produce high boiling pitch and distillation oils to be distilled to produce, with the aid of the tar thus distilled, 'CI-eg. - Lies in much greater distillation oils than those which had been obtained to date, to the knowledge of the applicant, by any of the methods of distillation

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 tillation previously applied.



   The process according to the invention is a continuous process in which the tar to be distilled is heated by its direct contact with gases at high temperature; the tar is introduced into these gases in a pulverized state and the volume, intensity, uniformity and perfection of the distribution of the tar thus introduced is such that the tar is rapidly heated and distilled, the superheated gases are rapidly cooled to a temperature considerably lower than their initial temperature, they are effectively freed of the entrained pitch and of the carbon they contained,

   and the amounts of distillation tar and superheated gas supplied per unit of temp for the distillation are controlled such that a high melting point pitch can be produced and removed directly and continuously and that it can be , by distillation, to obtain an extremely high clean oil yield by removing the mixed gases and vapors while still at a high temperature and cooling them to condense the distillation oils.



   The present invention provides a particularly advantageous process for the distillation of coke oven tar at a coking plant and allows such tar to be distilled by producing a remarkably high proportion of distillation oils, for example about 75% or more of the tar. distilled tar, and a pitch melting at a high temperature, for example vex 200 C or above.

   The present process also has advantages for the distillation of tar when not obtaining the maximum melting point pitch and maximum oil yield and allows tar to be distilled to produce pitches. lower melting point and a lower percentage of oil with

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 many advantages including perfect gas washing and cleaning, almost instantaneous cooling of the gases to a temperature almost equal to that of tar or pitch during distillation),

   the rapid and efficient heating of the tar or pitch to a temperature nearly equal to that of the gases and the use of nearly maximum distillation capacity of the gases to the point where they are cooled in the boiler.



   When this process is thus carried out in cocoa houses, advantage is taken of the hot gases leaving the coke ovens by introducing these gases continuously into a distillation boiler at or towards the maximum temperature which they possess at. their output from individual coke ovens.

   The material to be distilled, for example ordinary or partially distilled tar, is continuously introduced into the boiler and forced to pass through it and is sprayed in the divided state in the hot gases of the coke oven. in such quantity and with such intensity and uniformity that the coke oven gases are immediately cooled from their maximum temperature to a appreciably lower temperature, the tar or pitch is simultaneously heated and rapidly distilled, and the hot gases are so thoroughly washed that they are free of all or most of the entrained carbon and pitch particles.

   The resulting mixture of coke oven gas and vaporized oils is continuously removed at high temperature from the boiler and is then cooled to condense the oils; and the pitch produced is also continuously withdrawn from the boiler.



   The gases leaving the coke ovens leave the glowing upper parts of the ovens at a high temperature, for example in the region of 550 to 8000 C or more, depending on the circumstances. the construction of coke ovens, the coking cycle,

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 the degree of coking, etc. The temperature of these gases is higher than that at which the coking of the pitch takes place, but this coking is practically eliminated in the present process by bringing the hot gases immediately to their entry into the the distillation boiler,

   in contact with an extremely large volume of tar or pitch in a divided state which is at a much lower temperature and which therefore possesses to an adequate degree the power to absorb sensible heat and latent heat from gas. The effect of an intensive spraying of tar or pitch in a divided state in the gases is to suddenly and rapidly cool the gases to a temperature much lower than their initial temperature and at the same time , to heat the tar or pitch and to distill the vaporizable elements from it quickly, but uniformly and in a controlled manner.

   In this way, the gases are rapidly cooled to a temperature such that harmful coking can easily be avoided while taking advantage of the high temperature and the large amount of heat of the gases in a particularly advantageous manner. rapid distillation of materials such as tar, pitch, tarry oils, etc.



   The application of these gases at high temperature has the further advantage that, even after having been cooled by the distillation of the tar and the pitch, said gases can still have a high temperature. For example, when making molten pitch at 2000 C, these gases may still have a temperature of 3500 to 400 C after distillation and can be removed from the boiler 4 at such high temperaturesa, which presents advantages. ages that will be indicated later.

   The washing of the gases at high temperature is carried out effectively so that the gases are perfectly free of dust, pitch elements, etc., entrained and that the distillation oils which separate out together.

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 As a result, the gases by condensation are free or substantially free from pitch elements and the like, these elements being removed from the gases and incorporated into the pitch residue.



   The present invention provides an improved process for distilling oils, tars, tar oils, pitches, etc. from a variety of sources. In the case of tars these tars may be coke oven tars, gas retort tars, water gas tar or tars from other sources. Tarry oils or other oils can be distilled in a similar and advantageous manner, in particular those which leave a fluid residue on distillation and those which, when distilled by the usual methods, undergo a high degree of decomposition resulting in a great loss of distillation oil.

   In the case of a coke oven tar, for example, the tar may be the total tar produced at the coking plant, the heavy tar separated in the collector barrel, or the light tar or tar oil separated in the condensers. In the case of coke oven tar distilled at a coking plant using hot gases from coke ovens, the gases employed for the distillation may, after they have been cooled to separate the oils from it. distillation, be combined with the rest of the gas produced in the coking plant.



   The high temperature gases used for distillation can come from a variety of sources, including retorts, gasifier, water gas machines, and other carbonization, distillation and gasoline processes. - coal fication, but the process is particularly advantageous when carried out with hot coke oven gases which are available in large quantities at coke plants and which contain a large quantity of heat which

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 is usually lost in the ordinary operation of these coking plants.



   The gases exiting the horizontal gas retorts have a temperature of 500-700 µ or even much higher and can advantageously be applied to the distillation of the tar which normally separates from the gases upon cooling. Likewise, lean gas, which leaves the gasifier at 500-800 C, and water gas, which leaves the machines at 600-800. C, are usefully applicable in the present process. These and other high temperature gases are used in the present process to distill tar, tarry oils, pitches, etc., in a particularly advantageous manner.



     The apparatus applied according to the invention comprises a distillation boiler provided with means for: a) introducing the hot coke oven gases or other gases at high temperature; b) introduce the tar, pitch or other product to be distilled; c) removing the distillation residue; andd) removing the mixture of gas and steam from the boiler and cooling this mixture with a view to separating therefrom the distillation oils, etc. If it is a question of taking advantage of all the distillation power of the gas, the boiler should be in such a position that hot coke oven gases can enter it at a temperature not much lower than that at which they exit from individual coke ovens.



  It is therefore advantageous to place the boiler on the coke oven bank and to have the necessary number of individual ovens communicate directly with this boiler so that the gases from the furnaces enter the boiler if it has suffered a drop of high temperature.



  However, the hot gases could be led to a boiler in another position. Any moderate fall

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 temperature that the gases are likely to undergo, can be compensated by the supply of a certain quantity of gas at high temperature.

   The volume and composition of the coke oven gases exiting from adjacent wells vary, this volume being relatively large at the start of coking, when the oven has just been loaded !, but being much smaller towards the end of coking. before diversion., Adjacent kilns are usually loaded at different times, so that, for example, by the time a kiln is loaded, the adjacent kiln on one side is already quite advanced in the period coking oven, and the adjacent oven on the other side is itself quite advanced but to a different degree.

   Consequently, if one connects the gas intakes of the individual furnaces in such a way that the variations in the quantity, composition and temperature of the gases coming from the various furnaces are compensated, one will continuously obtain for the distillation, gases - of which the volume and average composition will be approximately constant.



   Individual gas ovens are usually connected at one end to a glued barrel. The distillation boiler may advantageously be located on the other side of the coke oven battery and be connected to the required number of ovens by communication pipes. or individual exhaust columns, so that some or all of the gas from this furnace can be transferred to the boiler for distillation.

   The location of the boiler will vary according to the construction of the eokerie, the location of the barrel or barrel, etc.,. Instead of placing the boiler immediately above the coke ovens and connecting the individual ovens separately to the boiler, the boiler can be placed.

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 at a certain distance from the ovens, at one end or side. battery, and connect it by a collector suitably insulated to the required number of ovens, as described in more detail in the patent application filed by the same applicant, on the same date as the present and entitled : Method and apparatus for the distillation of tar and the like.

   In general, when the gases leaving the furnaces are used for distillation, these furnaces are isolated from the ordinary barrel with the aid of shutters, so that all the gases from these furnaces pass through the boiler and the boiler pipe. related gas treatment. Obviously, a greater or lesser number of individual ovens can be connected to the boiler, depending on the amount of tar to be distilled and other considerations.



   To take full advantage of the high temperature and the large amount of heat of the superheated gases, for example in order to achieve the maximum distillation power and produce a pitch melting at a high temperature, it is important to heat insulate the boiler and avoid cooling the gases as much as possible after they have left the coke ovens and before they enter the boiler. Heat loss can be reduced to a minimum by strongly insulating the boiler and the communication pipes.



   The tar to be distilled can be coal tar containing the small proportion of usual water. Tou- tefoie, as the sensible and latent heats of water are high in comparison with those of coal tar oils and the boiling point of water is low, the distillation power of water can be considerably increased. a defined quantity of hot gases by preheating the tar to remove water from it before introducing it into the

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 boiler, for example at a temperature close to 1000 C but preferably a little higher;

   and 1 a further appreciable increase in distillation capacity can be obtained by preheating the tar to a higher temperature in order to provide, by means of low temperature sources, as much latent heat as possible and Sensitive necessary to distill low and medium boiling point oils. For example, by increasing the preheating of the tar from 100 C to 2000 C before it is admitted to the boiler. the distillation power of a unit of hot gas was increased by about 40% to produce a pitch of the same melting point (around 2000 c); and the power of dis-. The concentration of a cubic meter of gas was increased from about 1.04 liters of tar to about 1.44 liters of tar.

   The following examples show the distillation power of hot gases at different inlet temperatures of the tar. The tar preheated to the higher temperatures was preheated by the hot enriched gases exiting the boiler. In all cases, the hot gases penetrated to about 6500 and the applied tar contained 2% water by volume. The power of. distillation is expressed in liters of tar per cubic meter of gas, the volume being referred to normal conditions.

   A melting pitch at 2000 C was obtained in each case,
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<tb> Temperature <SEP> of <SEP> tar <SEP> Power <SEP> of <SEP> distillation
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<tb> 70 <SEP> C <SEP> 0.93 <SEP> liter <SEP>
<tb>
<tb>
<tb>
<tb>
<tb> 100 <SEP> C <SEP> 1 .-- <SEP> "
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> 150 C <SEP> 1.25 "
<tb>
<tb>
<tb>
<tb>
<tb> 200 <SEP> C <SEP> 1.56
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> 250 C <SEP> 2.15 "
<tb>
 
It is obvious to those skilled in the art that, in using the heat of a fluid at low temperature, for example for preheating to provide sensible and latent heat at low temperature,

   we can keep the

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 high temperature heat of the hottest gases to provide the latent and sensitive high temperature heat required for the production of high melting point pitch and high oil yields; the gas distillation power can, as we have seen, be considerably increased by preheating the tar or other product to be distilled,
The preheating of the tar, before its introduction into the boiler, can advantageously be carried out by a heat exchange with the hot gases and vapors leaving the boiler.

   The temperature of these gases and vapors is so high that a very significant preheating of the tar can be carried out at the same time as a cooling of the gases and vapors and a condensation of part of the oil elements. heavy that they contain. Of course, other heat sources can, if desired, be applied alone or in addition to the heat of the distillation gases to preheat the tar.



   It is particularly advantageous to preheat the tar to be treated and then to bring it into direct contact with the hot gases and vapors leaving the boiler. It is thus possible to partially distill the tar and increase the concentration of oil vapor in the gases without condensing and removing from the mixture of gases and vapors a significant fraction of the heavier vapor elements of this mixture.



  The tar thus preheated and partially distilled can then be supplied to the boiler. The distillation power of the boiler can thus be considerably increased and the percentage of oil vapors contained in the exhaust gases and vapors also significantly increased. For any particular pitch melting point, the temperatures of the gases leaving the boiler will vary somewhat according to the degree of preheating imparted to the tar brought into contact with the

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 exhaust gas, but even with a relatively low degree of preheating, the temperature of the exhaust gas is still low enough to avoid any practical difficulties.



   It is important, in the practice of the present process, to introduce the tar or pitch quickly. in hot gases by sprinkling: an intensive projection or spraying of this tar, so that the gases come into contact in an immediate, continuous and perfect manner with the particles of tar, which all parts of the boiler are thoroughly watered and washed with liquid pitch and that the walls are kept free from coke deposits.

   It is important not to produce any local heating of any part of the boiler
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 and, to avoid this overheating at all times, it will be ensured that the boiler contains constantly in the pulverized state, a quantity of tar (if necessary partially distilled) sufficient to absorb the heat of the hot gases while being itself. even transformed into pitch of the desired melting point by gradual and controlled distillation.

   It is im- portant to avoid insufficient pitch or partially distilled tar on all exposed surfaces of the still, since such insufficiency would locally cause excessive distillations and formation. of coke, due to the high temperature of the extremely heated gases. Therefore, it is appropriate that
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 all interior surfaces of the distillate apparatus are continuously and intensively washed with a stream of partially distilled pitch or tar.

   The same perfect and abundant washing of hot gases by tar,
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 oee appropriate partial distilled, the washing determined z rprrrià # s &qn;.: -ze, 7 and s rapid distillation of 6ea- "j 1; z =, gçs == e / = s ± => ce head * leo fS! H #S éee {RSSS ".o, .r ... a t ... 'lû.u sla Jis'T3 fytS..e $ ..

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 these from the boiler by partially distilled pitch or tar and prevent local overheating and coking on these surfaces. It is important for the best results that the boiler is of such size and shape that large amounts of material in the divided state reach all interior surfaces.

   It is also important that internal devices such as: exhaust columns, shutter mechanisms, etc., are arranged so that all exposed surfaces are heavily sprayed with pitch at all times.



   This perfect and abundant sprinkling of gases by the tar or pitch projected on them in a divided state, is effected by mechanisms whose nature, 1. erupla encircles and functioning are such that they achieve the intended goal, this is important, not only to ensure a large evaporation and distillation area, but also to ensure the presence, in the gas capacity of the distillation boiler, of a sufficient amount of tar to absorb the heat of the hot gases which It contains, for baling and washing the internal surfaces of the boiler with tar, to prevent the formation of harmful coke and to properly wash the gases to remove pitch or carbon particles therefrom. Various mechanisms can be applied for this purpose.

   In general, they should be immersed in the tar or pitch which is at the bottom of the boiler and that, by a rapid rotational movement or the like, they project large quantities of this tar in the state. , divided in gases, in all parts of the boiler and against all exposed surfaces. A sprinkler or spray mechanism comprises one or more rollers or elongated horizontal cylinders, including the cylinder surface. drique plunges into the tar or pitch which is at the lower part of the boiler and which is animated by a movement.

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 of rapid rotation, so that they project the tar in a divided state into the gas space of the boiler.



   The surfaces can be smooth or have circumferential grooves or ribs or discoid projections.



   As regards the most general characteristics of the invention, the latter is not limited to any particular spraying mechanism and includes any suitable spraying mechanism to ensure sufficient agitation of the tar and to spray or project this tar at 1. divided state in the gases, to keep the walls of the boiler continuously sprayed with this tar and to effect the abrupt cooling of the gases and the rapid distillation mentioned above, as well as to wash the gases perfectly.

   a spraying member of generally cylindrical shape, such as a smooth cylindrical roller or one provided with circumferential grooves or protrusions, is particularly advantageous because it allows the distillation to be carried out with the minimum of difficulty, as regards the coke formation and with the production of a high melting point pitch and remarkably high yield of distillation oils using the treated tar.

   it will be noted that the pitch is thrown repeatedly, into the gases and onto the exposed surfaces of the boiler, so that on its way through the boiler any unitary particle of pitch may be thrown into the pipes. gas a lot of times. In this way, a high degree of intimacy between the gases and the pitch and a regular and controlled increase in the temperature of the pitch is achieved, these various factors contribute to the functioning * - '; of the installation considered as a whole.



   In the case of a boiler individually connected to several coke ovens, the hot coke oven gases enter the boiler at a corresponding number of points.

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  Tar will ordinarily be admitted to one end of the boiler, with high melting pitch being removed from the other end. If the gas and vapor outlet is located near the middle of the boiler, the gas and tar streams will generally be in the same direction at one end of the boiler and in reverse at the other end.

   If the outlet for gases and vapors is located near one end of the boiler, the pitch can be removed, either from the same end or from the opposite end, and the tar can be removed. introduced at the end opposite to the pitch outlet. The general streams of gas and tar will then either be in the same direction or in opposite directions, each of these working methods has certain advantages and certain disadvantages.



   When the gas stream and the tar and pitch stream are generally in the same direction, the hot gas leaving successive individual ovens enters the boiler in contact with tar, possibly partially distilled, and of pitch of increasing melting point, and the gases and vapors leave the boiler in contact with the final pitch. In this case, the temperature of. exhaust gases and vapors is relatively high and the distillation power of hot gases is lower than when the streams are generally in reverse.



   When the gas flow and the pitch flow are generally in opposite directions, the hot gases coming out of the individual ovens first come into contact with a more or fully distilled hot material, moving in opposite directions of the tar and the tar. pitch during distillation and leave the apparatus in contact with the incoming tar, the temperature of which is relatively low. In this case, the temperature of the exhaust gases and vapors is lower than when the currents are in the same direction and the power of

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 hot gas distillation is relatively higher. In the case of currents in the same direction, the final pitch leaves the boiler at a lower temperature than in the case of currents in reverse directions.



   The production of a pitch with a melting point as high as 200 C or above requires care because the risk of coke production is considerable if the process is not properly controlled. A relatively low degree of improperly controlled distillation is sufficient to convert a pitch melting at about 2000 C into the material usually called "coke" and it is important, in order to avoid this conversion, to avoid local overheating and to ensure the maintenance of a a suitable and well-regulated balance between the quantity of gas applied for the distillation, the quantity of tar distilled and the degree of spraying of the tar or pitch introduced into the gases.



   It is therefore evident that various factors of the process need to be studied and adjusted with respect to each other in view of the desired distillation.



  The high temperature gases applied may vary with respect to their temperatures and distillation power, as well as with respect to the volume of gas available.



  To ensure maximum tar distillation with a high yield of distillation oils and the production of a high melting point pitch, while avoiding harmful side- faction of the produced pitch, it is important to carefully control the amount of tar. tar and pitch brought into contact with a given quantity of hot gases, the temperature of the tar and other process factors, as previously indicated.



   It has been found that the process and apparatus according to the invention are eminently suitable for industrial operation on a large scale. As an example of
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 J /

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 embodiment of the invention, the following will be mentioned: an installation distilled for 10 months approximately 7,570 cubic meters of coke oven tar, producing approximately 5,680 cubic meters of distillation oils and a pitch with an average melting point, is around 1930 C. The distillation of coke oven tar has given oil yields of 75% or more over long periods of time with pitch melting at about 2000 C or above. Pitches melting at 224 and 232 ° C have been obtained for considerable periods of time.

   The coke oven gases entering the boiler had a temperature of around 550 ° C or above. The temperature of the gases and vapors leaving the boiler has varied, for example, from 350 to 4000 C. As an example of the application of the invention to the production of a pitch melting at 149 C with hot gases 5500 C approximately, the gases and vapors had a temperature of approximately 3060 C when they left the boiler and the pitch remaining in the boiler had a temperature of approximately 3280 C; whereas when a pitch melting at 200 C was produced the gases and vapors left the boiler at approximately 3240 C and the pitch remaining in the boiler had a temperature of approximately 3550 C.

   The boiler in this installation was approximately six meters in length and a square cross-section of one meter wide by one meter high, and six furnaces were connected by individual exhaust columns to this boiler.



   The total distillate produced by the present process, and which can be as large as 75% or more of the tar distilled, can be condensed as a single composite oil and used, for example, as creosote oil; or the mixture of gas and vapor can be cooled and condensed in a fractional fashion and obtained several fractions of oils.

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 of the oil produced had a specific gravity at 38 ° C of 1.110 and contained only a trace of free carbon. When this sample was subjected to distillation according to the A.S.T.M. process, 1.1% distilled to 200; 2.3% distilled between 2000 and 210;

   8.3% between 210 and 235; 22.4% between 2350 and 270; 34.3% between 2700 and 315; 48.8% between 3150 and 3550 and the percentage of coke residue obtained pex relative to the oil was 1.9%. It is obvious that the distillation can be carried out without producing the maximum yield! in oils and pitch of maximum melting point and that, under these conditions, the process lends itself advantageously to the distillation of a larger quantity of tar in order to produce a pitch of lower melting point and a yield. in oils correspondingly decreased;

   but the distillation will nevertheless be accompanied by a remarkably high yield of oils corresponding to the melting point of the pitch produced. When distilling coke oven tar, for example, in simple externally heated boilers of 37.85 cubic meters volumetric capacity, the oil yield is only about 44% when distillation J is pushed. to the point of producing pitch of about 1490 C ,,, and coking can begin before reaching pitch, melting at 200 C.

   By other distillation processes, somewhat higher oil yields can be obtained up to a melting point of 149 ° C for pitch, but a pitch melting up to a temperature as high as 200 ° C. could be obtained only at the cost of extreme difficulties.

   The present process, on the other hand, makes it possible to produce, in a completely satisfactory manner, a pitch melting at 200 ° C.; and yields of 75% or more of distillation oils can be obtained by distilling coke oven tar until a pitch melting at about 2000 C or above is obtained, while performing the distillation. in sight

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 By producing a lower melting point pitch, around 149 ° C, oil yields of about two-thirds or more can be obtained from the distilled tar.

   It is evident that different tars will vary, as regards their oil content, depending on the coal being coked and the nature of the coking, so that the percentage of oil which can be obtained using a coke oven tar from a factory, may not be the same as that which is Possible to obtain from another factory working with types of different furnaces on different coals and during a different coking period or with furnaces of different dimensions,
The invention will be described below in more detail, with reference to the accompanying drawings which show one of the improved apparatus according to the invention and apparatus arranged to carry out the method according to the invention,

   these drawings are schematic.



   Fig. 1 is a partially cutaway plan of part of a coking plant and shows part of the ordinary by-product recovery apparatus as well as the improved apparatus according to the invention.



   Fig. 2 is a vertical section on a larger scale of a still boiler constructed in accordance with the invention.



   Fig. 3 is a vertical section along 3-3 (fig.2).



     Fig. 4, 5 and 6 are vertical sections showing other arrangements of chambers or settling towers arranged to replace the tower of FIG. 2.



   Fig. 7 is a plan of fig, 2.



   Fig. 8 is a horizontal sectional detail of fis2.



   Fig. 9 is a cross section along 9-9 (fig.



  7 and 8).

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   Fig. 10 is a view on a larger scale with partial section of a type of fractionation condenser.



   Fig. 11 and 12 are horizontal sections following
11-11 and 12-12 (fig 10).



   Fig. 13 is a schematic view showing the distillation boiler and the condensing apparatus of FIGS. 1 to 3 and 7 to 12.



   Fig. 14 is a schematic view of a boiler established to work against the current.



   Fig. 15 is a similar view of a boiler set up to work partly with currents in the same direction and partly with currents in opposite directions.
Fig. 16 is a schematic view of a boiler established to work with streams of the same direction and provided with a device supplying tar directly to. boiler or tower and an indirect downdraft condenser.



   Fig. 17 is a schematic view of two boilers, one set up to work with currents in the same direction and the other to work with currents in the opposite direction, these boilers being fitted with devices making it possible to supply tar to both. boilers, to remove pitch from both boilers or to distill the pitch successively in the boilers.

   Means are also provided for carrying out the direct fractional condensation of the oils.
Fig. 18 is a schematic view of two boilers: arranged to work against the current and so that the pitch passes from one of these boilers to the other, these. boilers being provided with separate gas and steam outlets and means for preheating the tar; by its indirect contact with the hot vapors and gases from @ two boilers.



   In the accompanying drawings, part of a battery

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 of coke ovens is shown schematically at 1 and part of the usual by-product recovery system is shown in fig. 1, the individual coke ovens 2 being provided with exhaust columns ± terminating in a cylinder. common to a number of battery ovens.



  The transverse pipe connects the barrel to the condensers 6, and the gases then pass through the enhancer 2. to the ammonia absorber, to the benzol scrubber, etc.



  Usually, an ammoniacal liquor or a mixture of this liquor with tar is introduced into the barrel to cool the gases and wash the walls of the barrel with a stream of liquid. indicates a drain pipe through which the tar and the ammoniacal liquor are led to a settling tank 9, the tar of which is transferred to the tar receptacle 10. The condensers 6, which can be direct condensers, are fitted with devices allowing transferring the coolant and the light tar to a decanter 11. A suitable container (not shown) collects the ammoniacal liquor from this decanter, and a container 12 collects the light tar from this decanter.



   The apparatus described so far, and which has only been shown schematically, varies somewhat in different coking plants and has only been described for explanatory purposes. It operates in the ordinary manner, except for the modifications made by the present invention.



   One or more distillation boilers are provided for convenience on the side of the coke oven battery opposite to that of the barrel, one of them being shown at 32 .. this boiler has, as shown, a rectangular cross-section, and its length is such that four exhaust columns from four individual furnaces, open into said boiler, these columns being shown in the form of

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 internal columns 21. Two additional exhaust columns 22 connect the boiler to furnaces located beyond the ends of this boiler and enter the boiler through said ends.

   The internal exhaust columns 21 have side openings opening into the boiler and shutters 23, operated by control levers 24, make it possible to close the individual columns during the filling of the coke ovens or when wishes to isolate any furnace from the boiler. Cleaning openings 25 are provided for each of the exhaust columns. Obviously, the location and arrangement of the exhaust columns from the individual ovens to the boiler may vary.



  For example, all columns can be external columns.



   The boiler and the external columns are highly insulated, as shown, to prevent or reduce heat loss and to prevent the temperature of the gases entering the boiler from decreasing. In some of the figures not all or part of the heat-insulating coatings have been shown, but it goes without saying that the pipes or parts of the apparatus which contain tar, pitch or hot gases will ordinarily be heat-insulating for prevent heat loss. If the thermal insulation is satisfactory, the gases will enter the boiler at a temperature not much lower than that at which they come out of the individual ovens and there will be available for distillation gas having the maximum temperature.



   The outlet pipe for the gases and vapors from the boiler opens at 27 into a large chamber 28 which constitutes both a deposition chamber and a distillation chamber used to preheat and distill the tar as will be described below, A baffle 29 is placed

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 above the entrance to the duct in the bedroom. The gas and vapor exhaust line 30 from chamber 28 leads to a condenser 31, which here is a three-stage fractionation condenser. From the bottom of this condenser, the cooled gases pass through a pipe 32 to the gas treatment apparatus of the coking plant and enter this apparatus between the condensers ± and the exhauster 7.



   The condenser shown is a three-stage condenser having two lower cooling sections cooled by a suitable coolant such as water and an upper cooling section 34 which serves as a preheater for the tar and as a preliminary condenser for the gases and vapors. . The upper section or tar preheater is provided with a 35 tar supply pipe leading to tar coils.
36 at the outlet of which the preheated tar passes through a pipe 37 to a distributor or spray head 38 placed in the tower 28 between two sections 39 and 40 filled with crushed material or cylindrical rings, for example rings
Well-known Raschig.

   The upper section 39 serves to decrease the entrainment of suspended particles and the lower section 40 performs the same function and further serves to bring the preheated tar into intimate contact with the mixture of gases and vapors leaving the chamber. boiler. The preheated tar is thus partially distilled and the residue accumulates at the bottom of tower 28 in the header section 41 and passes through a pipe 42 to one end of the boiler.
20.



   At the other end of this boiler is arranged a pitch exhaust duct constituted, in this case, by a pit 43 provided with an adjustable overflow duct, 46 leading to a trough or channel 47 which receives a supply pipe 44 a stream of water animated by a rapid movement

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 pide The pitch is granulated by rapid cooling in the water of the trough, at the outlet of which the water and the granulated pitch are collected in a container 45. This method of cooling and treating the pitch does not constitute only one of the various processes that can be applied. For some purposes, the pitch can be cooled without water to provide a solidified pitch free from water.



   In the boiler 20 are placed suitable atomizing or sprinkling devices for introducing the tar and pitch into the gases in a pulverized or divided state and in such a manner that all parts of the gases which the boiler contains are perfectly washed with tar and pitch and that all internal surfaces of the boiler are swept or washed with excess tar; or pitch. When internal exhaust columns are applied, the space behind these columns, a place that the projected tar cannot reach, is filled with a suitable material 70, as shown in fig.8.



  The mechanical sprinkler devices shown are; cylindrical rollers about 25 centimeters in diameter.



  There are three of them, indicated at 48, 49 and 50, and are operated at a relatively high speed, for example at 900-1000 revolutions per minute, by motors and 52 located at the ends of the boiler. The middle roller 49 is coupled with one of the end rollers at 53 and these rollers are actuated by one of the motors. In order to constitute bearings 55 serving to support the individual rollers, a part of the boiler is cut out or internally offset as indicated in 54 (fig. 8). The rollers plunge into the tar or pitch located at the bottom of the boiler, and the adjustable pitch outlet duct makes it possible to adjust the height of the tar or pitch layer, and consequently the immersion depth of the rollers.

   When this depth is shallow, the particles projected are relatively fine

 <Desc / Clms Page number 24>

 and the projected volume is relatively small. By increasing the depth of immersion, the quantity of tar or pitch sprayed and the proportion of relatively large droplets can be considerably increased. The nature and intensity of the sprinkling can therefore be regulated at will by adjusting the height of the tar or pitch layer.

   The volume of pitch at the bottom of the boiler can be considerably reduced by filling the lower angle opposite the roller to form a ramp 71, as shown in fig. 9. This decreases the volume of the pitch mass, ensures the repeated return of the pitch to the spray roller and decreases the time that the pitch is held in the boiler.



   As regards its most general characteristics, the invention is not limited to the preheating of the tar, just as it is not limited to the fact of introducing the tar into the exhaust gases and vapors. to perform partial distillation before entering the boiler. However, this preheating and this partial distillation are particularly advantageous and allow important advantages to be realized.



   The condensing apparatus shown in some of the figures is a fractionating apparatus, or with several stages, the first section or stage of which is a tar preheater in which the tar is preheated by its indirect contact with the Hot gases and vapors. The amount of tar distilled per unit time can be considerably increased by preheating the tar in this manner and at the same time cooling the gases to condense part of the distillates of said tar.



  The mixture of gas and vapors undergoes further cooling in the lower stages of the condenser, for example by their indirect contact with coils containing

 <Desc / Clms Page number 25>

 cooling water. The condenser apparatus of figs 10 to 13 comprises water inlet 60 and water outlet 51 conduits supplying the lower cooling sections 33. Three exhaust conduits 52, 63 and 64 have provided for the condensation products of the respective sections. Two return pipes 65 and terminating respectively in distributors fiz and 68 return the condensate from the upper section to the directly lower section where it mixes with the condensate separated in this section.

   By returning the condensate from each of the two upper sections to the lower sections, a condenser is obtained in which all the elements are condensed and collected together to be discharged through the lower exhaust duct 64. The construction of the conden - sor may vary and that of fig. 10 to 12 is only one of the various types of condensers that can be applied, but this particular condenser is advantageous and ensures the preheating of the tar to a high temperature before it enters the boiler,
The gases and vapors can be cooled in condensers of the direct type in which the cooled. Sement eet carried out by ammoniacal liquor brought directly into contact with the gases.



   The cooling of the gases can be carried out both by the condenser of the indirect type and by the condenser of the direct type. However, from the point of view of the subsequent treatments to which the gases may be subjected, each type of condenser has advantages defined in special cases. The direct condenser is in particular advantageously applicable to plants in which ammonia is recovered from the gases by the indirect system, such as for example in plants working according to the Semet-Solvay system, given that, in this system,

 <Desc / Clms Page number 26>

 Specially cooled ammoniacal liquor is available in large quantities to cool the gases.

   The required fraction of this cooled liquor is applied to the cooling of the gases and to the condensation of the oils in the still. The ammoniacal liquor separated from the oil is returned to the regular liquor circulation system.



   In factories working with the semi-direct system to recover ammonia, for example according to the Koppers system, most of the ammonia is recovered directly in the form of ammonia sulphate, which is obtained by passing the Coke oven gas through dilute sulfuric acid. A relatively small proportion of ammonia is recovered from the condensed aramoniacal liquor of the gases in the manifold, the oven barrels. coke and primary refrigerants. In this system it is desirable that the production of such liquor be kept at its minimum value, while in the indirect system very large amounts of water are continuously introduced to absorb ammonia.

   In addition, in the semi-direct system of the Koppers type, since no device is provided for cooling the ammoniacal liquor, cooled liquors are not available for directly cooling the gases coming from the still. In such a system, it is preferable to apply the condenser of the indirect type, since in this condenser a relatively small amount of ammoniacal liquor is collected and this liquor can be mixed with that recovered. gases which have not been used for the distillation.



   The tar supplied to the boiler may be that collected in the by-product recuperator of the same plant and may then be transferred, by pumps 56 and 57 and pipe 58, from tanks 10 and 12 to the boiler. We

 <Desc / Clms Page number 27>

 can also introduce a tar from another source of supply through a pipe 59 or introduce and distill mixtures of different tars, etc. This not only makes it possible to obtain pitches of a special nature by distillation, but also to regulate the nature of the oils obtained.

   The light and heavy tars from tanks 12 and 10 can be mixed in a tank (not shown), then pumped to the boiler through pipe 58; or they can be left separate and distilled separately. Light tars will give relatively high amounts of lighter oils, relatively rich in tar acids and naphthalene, while heavier tars will give relatively small amounts of heavier oils and higher amounts of tar. tar, and the oils will be relatively poor in tar and naphthalene acids.

   Thus, by separately distilling these light and heavy tars and by mixing them in suitable proportions, not only can the quantities of oil obtained for various pitches be regulated within certain limits, but also the nature of the oils and pitches obtained. .



   When the tar is not introduced into the boiler through the chamber 28, this chamber can be an open chamber, as shown in fig. 4. In this case, the tar can be introduced directly into the boiler from the end opposite the gas exhaust duct.



   When chamber 28 is open, it serves as a deposition chamber in which entrained tar particles from the intensive spray zone of the boiler are made to settle and return to the boiler. In a boiler in which the spraying or spraying is so perfect and so efficient as to achieve the objects of this invention, some of the particles projected tend to leave the boiler with the gases and vapors, and

 <Desc / Clms Page number 28>

 it is therefore important to allow these suspended particles to separate upon settling if it is to be avoided that these gases are contaminated with suspended pitch particles when the oils separate from said gases by condensation.

   The deposition chamber, suitably insulated to avoid cooling the gases and condensing the oil and in which the gas velocity is low enough to allow entrained pitch particles to settle, is suitable for the purpose.



   Fig. 5 and 6 represent other arrangements of deposit chambers or towers. In fig. b, the chamber 28b is provided with inclined baffles 39b over which the preheated tar passes, so that it provides a large contact surface for the gases and vapors rising inside the chamber. These gases and vapors are thus brought into intimate contact with the preheated tar with a view to its aistillation, and at the same time the arrangement of the baffles favors the elimination of the pitch particles entrained by the gases.



   In fig. 6, chamber 2 Se is provided with a series of trays 39c arranged so that the preheated tar flows from one tray to the next. The gases and vapors rising from the boiler pass over the surfaces of the preheated tar and help to distill it.



   The gradual distillation to which the tar is subjected for the production of pitch has the effect of vaporizing a large part of the oils contained in the tar to produce vapors which mix with the gases and remain in the vapor state. . The mixture of gases and vapors goes from the boiler to the exhaust duct 27 leading to the deposition chamber 28. With a deposition chamber such as the chamber 28a of FIG. 4, entrained pitch particles are brought to the same

 <Desc / Clms Page number 29>

 to be deposited, and the mixture of gases and vapors then passes into the condensing apparatus.

   With chambers such as those of fig. 2, 5 and 6 and 13 and a condenser in which the tar is preheated ;, the preheated tar is brought into direct and intimate contact with the gases and vapors which escape, and it follows that this tar undergoes heating complementary and partially distilled, the resulting oil vapors adding to the gases and vapors passing through the tower.

   The preliminary heating and distillation of the tar thus has the effect of increasing the distillation by the application of heat which would otherwise be wasted, increasing the vapor content of the gases and oils. also dramatically increase the amount of distillate per unit time, as the amount of heat that preheated and partially distilled tar entering the boiler requires in that boiler to be distilled and produce high melting point pitch is lower only in the case of unpreheated or not partially distilled tar.



   The following data were taken during the production of a pitch melting at about 2000 ° C. and will illustrate the invention. Tar was admitted to the preheater at a temperature close to 63 C and preheated to approximately 2210 C by its indirect contact with the hot gases and vapors, the latter themselves being cooled from approximately 2930 C to approximately 1750 C. the preheated tar then entered the deposition chamber where it undergoes a new heating and was distilled by its direct contact with the hot gases and vapors which this chamber contained and which were thereby cooled to a temperature of approximately 293 C before entering in the preheater.



   The intensive washing to which the gases are subjected in the boiler during the distillation, effectively separates

 <Desc / Clms Page number 30>

 the carbon and pitch particles suspended in these gases. It follows that when the gases and vapors leaving the boiler are subjected to condensation, the condensed oils are clean oils substantially free from tarry elements or based on pitch and it is found that they contain only traces. free carbon when subjected to the usual benzol extraction test.



   When tar is distilled by the present process to produce a pitch pitch. High melting, around 2000 C or above, the distillate contains heavy elements which, in isolation, are solid or semi-solid at ordinary temperatures. When the gases are cooled directly or indirectly to condense all or most of the vapors as a single composite product, the heavy elements remain dissolved in the lighter oils and form with them a precious creosote oil. The condensing apparatus shown enables total condensate to be produced by combining the condensate from the three sections of the condensing apparatus.



   In the operation of the apparatus and in the practice of the process according to the invention, the hot coke oven gases pass from the individual coke ovens to the distillation boiler at substantially their maximum temperature. , which can be preheated and partially distilled, is continuously introduced into the boiler, and a tar or pitch layer is maintained at the bottom of the boiler. This tar or pitch is -projected in a divided state into the gases of the boiler in such a large quantity and in such a perfectly distributed manner, that the gases at high temperature are rapidly cooled and the tar and pitch are quickly distilled.

   All exposed surfaces of the boiler are strongly swept and washed by &quot; the jet of tar and pitch, and the quantity of tar pro-

 <Desc / Clms Page number 31>

 jetty is so large that local overheating by gas is avoided. high temperature and that there is a rapid and efficient dilation of the tar and pitch and a simultaneous and immediate reduction of the temperature of the gases.



  The pitch is withdrawn at one end of the boiler while the tar, which can be preheated or even partially distilled, is admitted continuously at the other end. The tar admitted to one of the ends is gradually distilled and a pitch of progressively increasing melting point is obtained which leaves the boiler at its maximum melting point.



   In the apparatus shown, it is possible to connect the six ovens to the boiler in a continuous manner and to lead the gases from the six ovens through the boiler or to isolate one or more ovens by closing one of the exhaust openings opening into the boiler. boiler and by connecting this or these furnaces to the ordinary barrel.

   When the six furnaces are connected to the boiler, they are isolated from the usual barrel, the arrangement being such that all the furnaces can be connected either to the boiler or to the barrel, or that part of the tubes can be connected. furnaces to each of these two organs, '
The cooling of the hot gases and vapors for the condensation of the oils can be carried out so as to produce a single total condensate suitable, for example, in view of its application as creosote oil; or it can be made to produce heavier oils and lighter oils.

   In 1 apparatus of fig. the. 13 separate fractions can be removed from the individual sections of the condenser shown, ie through pipes 62, 63 and 64 of FIG. 10, the condensate withdrawn from the upper section being a heavy condensate and those withdrawing the lower sections being lighter condensates, these separate fractions can be used separately or mixed.

 <Desc / Clms Page number 32>

 processed in any desired proportion to produce particular oils for particular uses.



   The condenser of fig. 1 to 13 is an indirect condenser in which the gases and vapors do not come into direct contact with the refrigerant liquid. In some cases, it is more advantageous to use direct condensers in which the ammoniacal liquor or water is brought directly into contact with the hot gases and vapors to cool and condense them;. Or to carry out fractional condensation. by direct cooling with oils of lower boiling point.



   The apparatus of FIGS. 1 to 13 is an apparatus in which the streams of gas and tar or pitch passing through the boiler are generally in the same direction, the pitch leaving the boiler at the same end as that through which the hot gases and vapors s' escape. In this arrangement, the hot gases come into contact with fresh tar and partially distilled tar, and the relatively colder and more or less saturated gases leave the apparatus in contact with the final pitch more or less completely distilled. .

   In this procedure, the hot exhaust gases are not cooled in the boiler as much as they would if they left the distillation barrel in contact with the relatively cool and cool tar, so that they can leave the boiler at a higher temperature, in which case they can be used for further distillation of the tar in chamber 28.

   When applying these currents in the same direction of gas and tar, the risk of coke formation by local overheating is less, since the pitch more or less completely distilled is in contact with gases which are already more or less saturated with oil vapors and relatively cooler than in the case of one-sided currents

 <Desc / Clms Page number 33>

 reverse in the case of which the final pitch leaves the installation immediately after its contact with new hot gases having their maximum temperature. In the same direction flow system, the final pitch leaves the plant at a lower temperature than in the case of reverse flow, assuming the pitches have the same melting point.



   The apparatus of fig. 14 is a countercurrent apparatus in which the direction of gas flow is generally the reverse of that of tar and pitch through the boiler. In this figure, the chamber 28d is an open deposition chamber from the upper part of which the gases and vapors go to the condenser 34d containing the coil 36d serving to preheat the tar. The tar admitted by the pipe 35d is preheated by its indirect contact with the hot gases and vapors and has the effect of cooling these gases, the condensate being removed at 62d. The gases -, and vapors then pass into a condenser 33d in which they are subjected to a new cooling and to a new condensation), 1 condensed oil being withdrawn in 63d.



   The gas and tar streams pass through the boiler in reverse directions. The new hot gases at nearly their maximum temperature come into contact with the final pitch, and the partially cooled final gases leave on contact with relatively cooler tar. this allows the gases to be cooled to a lower temperature and to be used more efficiently in the boiler, but the need to take precautions to prevent overheating and coking of the pitch coming out of the boiler. :

  ) is increased since the pitch cokes more easily in contact with the hotter gases and the hotter surfaces of the boiler,
Instead of applying gas and pitch streams

 <Desc / Clms Page number 34>

 Usually in the same direction or generally in opposite directions, one can apply a combination of thematic currents in set and of opposite directions and obtain many of the advantages of both systems. Combined currents in the same direction and in reverse directions of this kind will take place in the apparatus of FIG. 15.

   In this arrangement, the tar (which can be preheated and partially distilled) enters through a pipe 42e at one end of the boiler, while the pitch escapes from the other end, during the first part of the boiler. movement of the tar and pitch through the boiler, the current is generally in the same direction as that of the gases, while the movement of the pitch through the other part of the boiler is generally counter-necked. - rant with respect to hot gases. The tar spray is so intense that the gases are quickly brought to or near a state of equilibrium with the tar sprayed on them.

   The arrangement of fig. This is such that the initial distillation of the tar and the production of a softer pitch are carried out with streams in the same direction, whereas a hard pitch is obtained with streams in the reverse direction.



   In fig. 15, a tower of the type shown in in FIG. 1 or a single 28th deposit room. The condenser of fig. 15 is a condenser cooled by direct contact with an ammoniacal liquor introduced at 6 Ce by suitable distributors and descending on grids or other filling material contained in tower 34e. The mixture of condensate and liquor s The 64th escapes and the ammoniacal liquor can be recirculated after separation, or another liquor can be used.



   In the apparatus of fig. 16, means are provided for admitting the tar directly to one end of the boiler and removing the pitch from the other end.

 <Desc / Clms Page number 35>

 you. Means are also provided for introducing all or part of the tar directly into tower 28f and bringing it into direct contact with the hot enriched gases passing through the tower to preheat and partially distill the tar, after which the resulting pitch enters the boiler. ,. The gas and pitch streams generally run in the same direction in the still barrel 20f. The tar can be introduced partly through the whole and] 1 partly directly into one of the ends of the boiler without preheating.



   The condenser of fig. 16 is an indirect downdraft condenser in which the coolant rises upon indirect contact with gases and vapors. The oil condensed in the upper part of the condenser flows downwards and washes the lower condenser coils, thus protecting them against any risk of naphthalene deposit. ¯
It is sometimes desirable to produce high melting point and low melting point pitches simultaneously. This can be easily done by removing pitch from an intermediate part of the boiler together with the pitch exhaust port at one end.

   It is also possible to provide two or more boilers for distilling pitches of progressively increasing melting points and to operate the boilers in such a way as to produce pitches of different melting points. Two arrangements of multiple boilers are shown in figs. . 17 and 18.



   In fig. 17, the boilers 20g and 20g 'are arranged so that the gases of the vapors leaving the first pass through the second. The tar is introduced directly into each boiler or directly into the tower through which the hot enriched gases pass to

 <Desc / Clms Page number 36>

 their exit from the boiler 20g '. Pitch is removed from both boilers and means are also provided for transferring low melting point pitch from boiler 20g 'to boiler 20g for further distillation. The arrangement shown 'provides for currents in reverse direction for pitch and gases in the boiler 20g' and currents in the same direction in the boiler 20g.

   Some of the low or medium melting point pitch produced in the 20g boiler can be removed as a separate product and the rest can be fed into the 20g boiler to undergo further distillation and give a point pitch. higher fusion. The combination of currents in opposite directions and currents in the same direction of fig. 17 thus differs somewhat from that provided in fig, 15.



   The tower 28g of fig. 1,7 can be similar to the tower 28 of fig. 13, tar being introduced (with or without preheating and partial distillation) into the boiler through the tower. The condenser of fig. 17 effects fractional condensation of the oils by direct contact with oils introduced into the cough, which oils can themselves be vaporized. The fractionation condenser 34g is a two-stage condenser provided with means for introducing the oil into each stage and removing the condensate from each stage.



   The two boilers of fig. 18 are arranged to allow the production of pitches of different melting points in the different boilers or, by operating the boilers in series, to produce a high melting point pitch with the aid of the second boiler.

   The 28h and 28h 'deposit chambers are provided without the introduction of tar or pitch through these chambers, but the condensers 34h and 34h' are indirect condensers through which

 <Desc / Clms Page number 37>

 the tar is brought into indirect contact with the hot gases and vapors with a view to its preheating ;. this tar then being introduced into the 20h 'boiler. The preheating of the tar is carried out in countercurrent, Means are provided to allow the transfer of the low melting point pitch from the 20h' boiler to the 20h boiler as well as to remove the low melting point pitch from this boiler. The tar (which may or may not be preheated) can be introduced directly into one or each of the boilers.



   Figs. 13-18, which are diagrammatic, show various arrangements of same-direction currents, reverse-direction currents or combined same-direction and reverse-direction currents for gas and pitch. These figures also represent various arrangements of condensers and various arrangements of preheaters making it possible to preheat the tar either indirectly or directly before introducing it into the boiler. It is obvious that we can combine the different processes? preheating and condensation represented in the different figures with the different operating modes with currents either in the same direction, or in reverse directions, or combined.

   For this reason, the different types of preheaters and condors have been represented with different types of gas flow and pitch in the boiler, instead of representing each type of boiler with the various types of preheaters and heaters. of condensers likely to be used.



   When a preheating and distilla tower'- '.; . tion is intended to distill tar by its direct contact with the hot gases and vapors coming out of the boiler, the action which takes place in the tower is generally. a counter-current action. this counter-distillation of the goûdron before it enters the boiler can

 <Desc / Clms Page number 38>

 be combined with a distillation either with streams in the same direction, or with streams in opposite directions, in the boiler, or with a distillation partly with streams in the same direction and partly with streams in opposite directions, as generally shown in fig. 13 to 18.

   In the case of the counterflow system, as the higher melting point pitch is in contact with the hottest gases in the boiler, the pitch leaves the boiler at a higher temperature and, as mentioned above, the risk of overheating and coke formation is greater, especially in the case of pitches with a high melting point, for example 2000 C. The amount of heat lost with the pitch is less and the pitch leaves the boiler at a lower temperature than when working with currents in the same direction.



   The temperature of the pitch leaving the boiler as well as the temperature of the gases and vapors leaving the boiler will vary to a certain extent with the operating mode, whether with currents in the same direction, with currents in opposite directions or with currents. partly in the same direction and partly in opposite directions for gas and pitch. With parallel or in the same direction currents for gases and pitch in the boiler, without tar distillation in the settling cough and with gases initially at about 5500 C, a pitch melting at about 2000 C can leave the boiler at a temperature of around 3600 C, and the gases and vapors can leave the decantation tower at a temperature of around 325 u.

   With flows in the same direction for the gases and the pitch in the boiler and with preheating and partial distillation of the tar in the settling or washing tower, a pitch melting at around 2000 C can leave the boiler at a similar temperature. of 375 C. - and .. the gases and, vapors little-

 <Desc / Clms Page number 39>

 wind leaving the top of this tower at a temperature of around 255 C.

   In the case of combined currents in the same direction and in reverse directions, as shown in fig. 15, together with preheating and distillation of. tar in the washing and settling tower: the pitch melting at about 200 C can leave the boiler at a temperature of 410 C and the gases and steam can leave the top of the tower at a temperature of 270 C. .



   It goes without saying that the temperatures indicated will vary according to the initial temperature of the hot gases in the coke ovens, the nature, temperature and water content of the tar, the thickness and the effectiveness of the heat-repellent coatings of the tar. 'equipment, etc ... The temperatures indicated' are those which prevailed under the existing conditions of devices of the types described.



   When the tar is preheated by its indirect contact with the hot gases and vapors in a separate heat exchanger, then introduced directly into the boiler, as in fig. 14 and 18, 11 can be preheated to a higher temperature than in the apparatus of FIG. 13 in which the gases and vapors leaving the whole and entering the tar preheater have a lower temperature;

   however, in the apparatus of fig. 13. the preheated tar will again be heated and partially distilled in the tower, as previously described.
The aforementioned temperatures will vary with the melting point of the pitch produced and with other working conditions, and the particular temperatures mentioned are for the purposes of understanding the invention only and do not limit it in any way. .



   In an apparatus such as that shown in which the gases from the six coke ovens pass through the boiler

 <Desc / Clms Page number 40>

 and wherein the tar is distilled to produce pitch melting at about 200 C, the average time required for the gases to pass through the boiler is only .1. to about 5 seconds and, during this time, the gases are cooled from an average temperature of about 6000 C to 250-350 C, for example. It goes without saying that this period of time will vary according to the initial temperature of the gases, the dimensions of the coke oven, the nature and degree of coking of the coal, etc.

   The figure shown indicates the order of magnitude of the period, when the tar is distilled in the boiler to produce a pitch melting at 2000
C, the average time required for the tar to pass through the boiler and its distillation in this boiler is only a few minutes, for example 2 to 10 minutes.



   This period of time will depend on several factors, but the time specified above indicates the order of magnitude of the period. Therefore ', we see that the heat of gases. heat from coke ovens is employed almost instantaneously during the short period of passage of the gases through the boiler, and the superheated gases are cooled almost instantaneously to a much lower temperature by their intimate and perfect contact with the projected tar and pitch. in the divided state.

   The tar and pitch are in turn thrown repeatedly into the gases and rapidly distilled, so that the time required to distill the tar and produce a high melting point pitch is very short. This time will vary with the dimensions and operation of the boiler and with the volume and nature of the tar or pitch contained in the boiler in service, very distillation will be a rapid distillation carried out continuously with gases at high temperature.



   The present invention makes it possible to produce a wide variety of pitches and oils and simultaneously produce

 <Desc / Clms Page number 41>

 pitches of various melting points as well as oils of various characteristics. High melting point pitches and intermediate or low melting point pitches can be produced simultaneously and removed from the same boiler or from different boilers. Creosote oils, tar or carbalic acid oils or other oil fractions can be produced directly. In addition, the oils will be clean oils substantially free of carbon or heavy pitch due to the intense scrubbing to which the gases are introduced during distillation and which removes "tar mist" particles therefrom.



   It is also seen that the present invention provides an improved process and apparatus for the distillation of tar having, inter alia, the following advantages. Extremely high yield of distillation oils and high melting point pitch are obtained; the distillation is carried out by the direct contact of the tar with gases at high temperature; the gases are suddenly and rapidly cooled by an extremely intimate contact with a large quantity of tar or pitch to be distilled, projected in the divided state; the tar or pitch in the divided state is rapidly distilled; the gases are effectively washed and cleaned by the tar and pitch projected in the divided state;

   the distillation is carried out in a continuous manner producing a liquid pitch of much higher melting point than that obtainable by any of the prior processes and an extremely high oil yield.



   It can also be seen that the distillation power of the process and of the apparatus can be radically increased by preheating the tar and introducing it into direct contact with the hot gases and vapors leaving the boiler at the same time that the vapor content of gases

 <Desc / Clms Page number 42>

 and that the tar is partially distilled, so that the boiler receives hot, partially distilled tar, which saves heat in the distillation and advantages in subsequent cooling, owing to the partial cooling of gases and vapors by the distillation of tar, and other advantages.



   This preheating and this preliminary distillation of the tar by the hot gases and vapors make it possible to considerably reduce the dimensions of the installation or, for an installation of given dimensions, to considerably increase its distillation power.



   As stated previously, the present invention is in particular advantageously applicable to the distillation of coke oven tars and other tars in coking plants and to the application, with a view to this distillation, of hot gases from coke ovens. As to the more general characteristics, it includes the application of other gases at high temperature. The process and apparatus are advantageous in coal distillation and carbonization plants which produce high temperature fuel gases which are useful for distillation and constitute a source of heat which would otherwise be wasted.


    

Claims (1)

ABSTRACT 1. process for the distillation of hydrocarbons such as tar, etc. by their direct contact with gases at high temperature and in particular gases laden with tar resulting from the distillation of coal, this process consisting in spraying or spray the gases in a repeated, continuous and abundant manner with the aid of the sprayed hydrocarbon in the divided state, in large quantities and in such a way that the gases are perfectly washed and freed of the particles of "mist. tar "in suspension, the hy- <Desc / Clms Page number 43> The hydrocarbon is rapidly heated and distilled, and the gas is cooled almost instantaneously to a temperature near that to which the hydrocarbon is heated, to separate the entrained hydrocarbon particles from the resulting gases and vapors and to cool. these gases and vapors to condense the hydrocarbon vapors in the form of clean oils. This process can, moreover, be characterized by the following points, together or separately: a) It is introduced continuously in a channel. on the one hand the gases at high temperature and on the other hand the hydrocarbon to be distilled and one continuously withdraws from said boiler, on the one hand the residue and on the other hand the gases and vapors resulting from distillation. b) The gases are introduced at a temperature which is not much lower than that at which they leave the coal distillation apparatus, and the quantity of tar or pitch supplied is regulated so that it is rapidly distilled. c) The amount of tar or pitch supplied per unit time is adjusted so that the tar is rapidly distilled to produce high melting point pitch and high oil yield, the pitch being removed from a continuously from the boiler and the gas and vapor mixture itself being continuously withdrawn and cooled in order to condense the oils. d) The admission of tar and the projection of this tar in the divided state are regulated in such a way as to ensure the distillation of more than 75% of the tar in the form of distilled oils and the production of a pitch residue melting at about 200 ° C. or above, the pitch produced being maintained in a fluid and homogeneous state. e) The gases and vapors are transferred from the boiler to a deposition chamber in which the particles of <Desc / Clms Page number 44> tar are separated from said gas before they are cooled to condense the oils. f) To preheat the tar before entering the boiler and cool the gases and vapors to condense the oils they contain, the tar is passed in indirect contact or in a heat exchange relationship with these gases and vapors. g) The hot gases and vapors leaving the boiler are brought into direct contact with the tar, preheated where appropriate, in order to effect a partial distillation of this tar before it enters the boiler. h) A small mass of tar or pitch is kept in an elongated boiler, tar or pitch is continuously introduced into one end of this boiler and pitch is withdrawn from the other end , the currents of pitch and gas through the boiler being either generally in the same direction, or generally in opposite directions, or again partly in the same direction and partly in reverse senna. i) The high temperature gases coming directly from the coke ovens are introduced into the boiler at several points along its length. j) The spraying of tar in the divided state is carried out by means of spraying elements of generally cylindrical shape immersed in the mass of liquid and animated by a rapid rotating movement. k) The point in the boiler at which the pre-heated tar is introduced is remote from that at which gases and vapors exit the boiler, and the pitch is withdrawn from a point remote from that at which the tar enters the boiler, the currents of pitch and gas passing through the boiler generally in the same direction, 1) The preheated tar is subjected to heating <Desc / Clms Page number 45> and further distillation by bringing this tar into direct contact with the hot gases and vapors leaving the boiler before introducing the preheated tar into the boiler. : or m) To produce several oil fractions in close proximity, the hot gases and vapors are subjected to fractional cooling or condensation, EMI45.1 n) Gas cooling and vaPElUI'S "'éhsude",: ;;; 4 !. v "'.'-" / is carried out so as to give a condensate of oils>' iotai. "; :: advantageously applicable as creosote oil., 8. An apparatus for the distillation of hydrocarbons * such as tar, etc ...;, this apparatus being because, by the fact that it includes a distillation boiler EMI45.2 arranged to contain a small mass of hydrocarbon, 8 means for admitting gases at high temperature to the boiler and for removing gases and vapors from the boiler, means for admitting the hydrocarbon to be distilled and removing the residue from the boiler and a mechanical propelling device arranged in the boiler and arranged to EMI45.3 , ¯, .J .., .., r, .. J :: 4!;: To project the hydrocarbon in the divided state into the gases and against the internal surfaces of the boiler with an intensity and a volume such that the gases are almost instantaneously cooled by the hydrocarbon thus projected at a temperature close to that of this hydrocarbon and that the latter is rapidly heated and distilled. this apparatus may further be characterized by the following points, together EMI45.4 separately \ ...- ² or selaarement.- #. '"' '' - $ pa) The projection device comprises a large cylindrical one B 'sgenerally arranged' herizpata 'lament and animated by a rapid rotational movement. b) a deposition chamber is provided to deposit the particles hydrocarbon projections entrained by the gases and vapors leaving the boiler. <Desc / Clms Page number 46> c) An indirect preheater and condenser are provided to preheat the tar and cool the gases and vapors so as to condense oils by indirect heat exchange between the tar and the gases and vapors. d) A tower receives, on the one hand, the gases and vapors leaving the boiler and, on the other hand, the tar to be distilled which is introduced into it in direct contact with said gases and vapors with a view to its preheating and its distillation partial before entering the boiler. e) The inlet and outlet ducts of the apparatus are so arranged that the gas and pitch streams pass through the boiler either generally in the same direction, or generally in opposite directions, or partly in the same direction. the same direction and partly in opposite directions. <Desc / Clms Page number 47> EMI47.1 <Desc / Clms Page number 48>