US1283229A - Coking pitch. - Google Patents

Description

R. A. LEE.

COKING PITCH.

APPLICATION FILED APR. 28. m7.

1,2832% Patented Oct. 29, 1918* nmu 5] vwewfoz I RALPH A. LEE, OF BROOKLYN, NEW YORK, ASSIGN OR TO THE BARRETT COMPANY, OF NEW YORK, N. Y., A CORPORATION OF WEST VIRGINIA.

COKING PITCH.

Specification of Letters Patent.

Application filed April 28, 1917. Serial N 0. 165,093.

To all whom it may concern:

Be it known that I, RALPH A. LEE, a c1t1- zen of the United States, residing in the borough of Brooklyn, county of Kings, and State of New York, have invented new and useful Improvements in Coking Pitch, of which the following is a specification.

This invention relates to the manufacture of coke from bituminous material such as coal tar pitch and the like, and has for its objects the conversion of such material into coke by means of heat and pressure in an expeditious and highly efficient manner.

The aforesaid material, as is well known, contains varying amounts of oils and other constituents which may be vaporized by heating to obtain a coke-residue. A substantial amount of such constituents must be removed, even in the case of coal-tar pitch of high melting point, 2'. 6., hard pitch. During the heatin rocess some of the said constituents usua ly break down forming new prod ucts often in part gases.

My invention has to do with results following from heating material such as coal tar pitch under pressure. It is important to note that wherever in my specification and claims I use the terms pressure without limitations I refer to super-atmospheric pressure.

It is well known that materials in the liquid or vapor form can be super-heated. For example, by supplying pressure a liquid can be heated above its normal boiling point, i. 6., its boiling point at atmospheric pressure, and still be maintained in liquid form instead of changing into vapor form. In such a case the liquid is said to be superheated and contains a certain amount of super-heat or'extra heat units. If the pressure is reduced to atmospheric, the superheat'becomes available for doing work and may act to cause the evaporation of a portion of the liquid, or to produce other effects. Also, a vapor can be super-heated so that it contains more than enough heat units to maintain it in thevapor form at a given pressure. Steam, for example, can be superheated and if brought into contact with cooler material under proper conditions can give up some of its heat units to act on the cooler material while at the same time remaining as-steam. I

I have discovered that under proper conditions the'super-heat, due to heating coaltar pitch under suitable pressure to a desired temperature is suflicient to start coking a portion of the pitch when at a less pressure. I have further discovered that as soon as the coking of pitch is begun the reaction is exothermic and is characterized by the evolution of a considerable amount of heat. In general, therefore, I heat the pitch under a pressure, for example, of pounds, to a temperature, preferably about that at which under such pressure it would begin to coke, say about 900 F. I then subject it to less pressure, while maintaining its container at about the same temperature as the pitch was while under 60 pounds pressure, say about 900 F. and conduct away the vapors evolved to suitable condensers. The super-heat made available by the reduction of pressure is suflicient to start the coking of a portion of the pitch and the exothermic heat from the coking reaction is suflicient to complete progressively the coking without requiring any heat from outside sources. Preferably, however, I supply a small amount of external heat to offset radiation losses and to hasten the coking operation.

In the accompanying drawings I have illustrated diagrammatically apparatus suitable for carrying out my improved process. The construction and operation of the apparatus therein illustrated is as follows Coal tar pitch, for example of a melting point about 300 F. heated to a temperature of about 700 F. to 800 F. is pumped from a reservoir by means of a pump (not shown) through pipe 1 to a preheater 2. The supply pump is regulated so that the speed of the discharge of the pitch passing through the conduit 3 of the preheater is such that the pitch is maintained under a pressure of about 60 lbs. above atmospheric and heat is supplied by as burners 4 so that the pitch is continuous y heated to a temperature of about. 900 F.

From the preheater 3 the super-heated pitch passes into the circulating pipe 5 which issupplied with Ts as 6, to connect said pipe to one or more retorts. From the pipe 5 the heated pitch passes into branch pipe 7 through valve 8 into pipe 9 and through nozzle 10 into the cokin retort 11, in which the pressure is preferably about atmospheric and around WlllCll a temperature preferably equivalent to about 900 F. is maintained by means of a heat jacket or flue 12 through Patented Oct. 29, 101%..

which heated gases flow to the exit chimney 13.

The super-heated pitch upon entering the coking retort 11 almost instantly separates into vapors and residue upon the release of pressure. The maintenance of a tempera ture outside of the coking retort equal to or somewhat abovethe tGll'lPGI'tltlll'G within the same, by means of a heat jacket or otherwise, prevents the heat liberated from escaping as a radiation lossand its activities are thus confined within the coking retort wherein it serves to volatilize certain portions of the volatile content of the pitch and also begins the coking operation which is continued by a second source of heat known as exothermic heat, 2'. e. evolved reaction-heat. The addition of the exothermic heat to the heat already liberated is suflieient to complete the operation and'a good commercial coke is thereby produced.

The vapors liberated and produced iri the retort pass through pipe 14 and valve 15 into the common vapor pipe 16 which connects all retorts, where more than one is used, with a condenser 17, maintained by a suitable heat absorbing medium at such a temperature as to condense a portion of the vapors. The distillate is then drawn through pipe 18 into receiver 19. Further condensers may be supplied if desired. The uncondensed vapors or fixed gases pass through pipe 20 into a suitable gas receiver 21 which is equipped with the usual water seal 92 in the well known manner.

After the charge has stopped giving off vapors, which is an indication that the coking operation is complete, the charge is dropped through door 23 that is operated on a hinge 24 actuated by chain release 25 and quenched by water supplying apparatus 26.

The above description is for one retort only, but any number of retorts can be operated either simultaneously or successively in series as desired.

The heating of the pitch to the desired temperature under the requisite pressure may take place in a container holding a suitable quantity and the pitch may remain in the same container when the pressure is reduced or it may be conducted to another receiver coincident with reducing the pressure. I prefer to heat the pitch continuously while it is being conducted under the desired pressure through a pipe and then discharge it in turn through spray or atomizing nozzles into a series of coking retorts in which the pressure is less. As soon as each retort has received a suitable charge the flow is diverted to the next retort and so on. The retorts may be heavily insulated or are preferably surrounded by gases about or somewhat hotter than the retorts themselves.

The heat and pressure, required to produce conditions suitable for working my invention will vary with the grade of pitch used. Usually pitch of a relatively low melting point, i. e. a soft pitch, will contaln a higher percentage of volatile material than a pitch of a higher melting point. This volatile material must be removed by heat to secure a coke product, and in consequence more heat will be required with a pitch of relatively low melting point than with a pitch of a higher melting point. Also the pressure used will ordinarily be higher.

Having thus described my invention, what ll claim and desire to secure by Letters Patent is:

1. The process of coking bituminous material liquefiable by heat, which consists in heating such material under substantial pressure to a temperature in excess of 600 F., and then reducing such pressure while maintaining the materials at a coking temperature, whereby vaporizable portions are vaporized and a complete auto-coking operation is effected.

2. The process of coking bituminous material lique'fiable by heat, which consists in subjecting the same to a fluid pressure in excess of atmospheric, while maintaining such material at an elevated temperature in excess of 600 F., and then materially reducing such pressure to vaporize certain portions of the material and effect the coking of other portions.

3. The process of making coke from bituminous liquids which consists in heating the same while subjected to a pressure of several atmospheres, to a temperature in excess of 600 F., then reducing said pressure by causing the vaporizable gases to expand in a confined space under substantially atmospheric pressure while still heated to an ele vated temperature and thereby efi'ecting the coking of portions of the material, and

separating the residual coke so formed minous liquids which consists in heating the same while subjectedtoapressure of several atmospheres, to a temperature in excess of 600 F., then reducing said pressure by causing said material to expand in a chamber maintained at an elevated temperature and under substantially atmospheric pressure and efl'ecting the auto-coking or portions of the material and separating the residual coke so formed from the vapor portions of the material in said chambers.

5. The process of coking hydrocarbon material liquefiable by heat, which consists in heating such material under substantial pressure to a temperature in excess of 600 F., and then reducing such pressure while maintaining the materials at a coking temperature, whereby the liquid portions are vaporized and a complete auto-coking operation is effected.

6. The process of coking hydrocarbon material liquefiable by heat, which consists in subjecting the same to a fluid pressure in excess of atmospheric, While maintaining such material at an elevated temperature in excess of 600 F., and then materially reducing such pressure to vaporize certain portions of the material and-effect the coking of other portions.-

7. The process of making coke from hydrocarbon liquids which consists in heating the same while subjected to a pressure of several atmospheres, to a temperature in excess of 600 F, then reducing said pressure by causing said gases to expand in a confined space under substantially atmospheric pressure while still heated to an elevated temperature, and thereby efiecting the coking portions or' the material, and separating the residual coke so formed from the vapor portions of the material.

8. The process of making coke from hydrocarbon liquids which consists in heating the same while subjected to a pressure of several atmospheres, to a temperature in excess of 600 F then reducing said pressure by causing said material to expand in a chamber maintained at an elevated temperature and under substantially atmospheric pressure, and effecting the auto-coking of portions of the material and separating the residual coke so for-med from the Vapor portions of the material in said chambers.

9. The process of coking pitchy .material which comprises heating it under pressure to substantially the temperature at which it would begin coking under such pressure, then subjecting it to a less pressure, conducting away the vapors evolved, employing some of the available pressure heat to initiate the coking of the balance of the material and then employing substantially the available exothermic heat to complete the coking operation.

10.. The process which consists in heating pitchy material in a container above the boiling point of a substantial portion of its vaporizable constituents while preventing such constituents from vaporizing, then materially reducing the pressure thus created, conducting away the evolved vapors and effecting the self-coking of the balance of the material treated at such reduced ressure substantially by the pressure heat and exothermic heat.

11. The process of storing super-heat in pitchy material by heating it under pressure above the boiling point of a substantial portion of its constituents, then utilizing this heat to initiate the coking of a portion of the material at a less pressure, and efi'ecting the self-coking of a substantial portion of the material at such reduced pressure by exothermic and external heat.

12. The process of storing super-heat in pitchy material by heating it under pressure above the boiling point of a substantial por tion of its constituents, then utilizing this heat to initiate the coking of a portion of the material at a less pressure, and effecting the self-coking of a substantial portion of the material at such reduced pressure by exothermic heat.

Signed at New York, in the county and Stage of New York, this 27th day of April, 191

RALPH A. LEE.

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