US2065643A - Method and apparatus for treating clays - Google Patents

Description

A A Q e A N s IL T s D. G. BRANDT 2,065,643

Dec. 29,1936;

METHOD AND APPARATUS FOR TREATING CLAYS Fil'ed March 1'7, 1934 f mum-:Naea

grzlkgHEATib I f w i M l l 4* l A a T .4 N w Q I gXII ENTORN D I g i VD 6-864 T Q 1 7 ATTOR'NEY Patented Dec. 29, 1936 This invention relates orn'cr METHOD AND APPARATUS FOR TREATING CLAYS David G. Brandt, Westfield, N. Doherty Research Gompany,

1., assignor to New York, N. Y.,

a corporation of Delaware Application March 17, 1934, .Serial No. 116,056 6 Claims.- (01. asa -2) to the revivification of contact filtering or decolorizing agents such as fullers earth, bauxite, charcoal, metal oxides and other decolorizing agents used forthe refining of mineral and vegetable oils. More particularly the invention relates to'a process and apparatus for revivifying or reactivating pulverized clays or other contact um oils.

Granular clays which oils are usual type of processes are not cause clays. Cert developed for materials used for refining petroleand filtering agents through percolated may be revivified in the multiple hearth furnace, but such entirely. satisfactory even for ain other processes have been washing fine clay on filters with various solvent agents and steaming has been resorted to for the purpose of ing and cleaning clays. However, process has been developed which partially revivify no satisfactory will completely revivii'y or reactivate clays or other treating materials particularly where they have a fineness in theneighborhood of 200 mesh.

The important object therefore of the present invention is to devise a process by which contact clays and treating agents may be completely reactivated or revivified for reuse. A further object of the invention is the provision of a novel apparatus for carrying out this process.

particularly adapted In general the process comprises the steps of drying the filtering agent,

mixing a regulated stream or quantity of the dried filtering agent to be revivified with conducting the res a stream of a hot carrier gas, ulting mixture through a heating zone, and supplying sufiicient oxygen to the mixture at various points during its travel through the heating zone iication and reoxidation permitting an abnormal After the clay or filtering fied, it is separate least a portion of this gas the treating zone.

Further objects to carry out the reviviof the agent without rise in temperature. agent has been revivid fromthe carrier gas and at is recirculated through and advantages of the invention will be apparent to those skilled in the art description taken in connection with the accompanying drawing in which Fig. 1 is a diagrammatic tion of an apparatus carry out the process of view partly in secparticularly adapted to the present invention.

in which the imp out. i

roved process may be carried line 2i the light constituents are removed with steam .decolorizing clay such as fullers earth.

The clay and oil mixture is introduced into the- 5 system through apipe 2 asa slurry and forced by means of a pump 4 through a conduit 6 connecting with pipe coils 8 mounted in a pipe still furnace Ill. The oil-clay mixture in passing through the coils 8 is heatedto a temperature sufficiently 10 highto vaporize substantially all of the oil constituents. If necessary a pressure may be main-. tained sufiiciently high to retain substantially all of the oilconstituents in liquid phase in the coils 8. In most cases however, the oil is permitted to 15 vaporize in the cells. I Heated oil-clay mixture is conducted from the pipe still furnace i0 through a valved transfer line ;I2 and introduced into a flash or vapor separating chamber l4 comprising the lower portion of a fractionating tower l6. In 20 order to facilitate the substantially complete removal of hydrocarbon vapors from the clay settling out in chamber l4, superheated steam may be introduced through a distributor l8, but the velocity of steam should not be so great as to prevent settling out of the clay. The amount of steam is also, controlled for the purpose of regulating the oil content of the clay.

The gasoline or naphtha vapors separated in chamber M are conducted through a vapor out- 30 let 20 into the upper part of the fractionating tower I 6 where the vapors are rectified 'in accordance with the usual practice'to give a final gasoline product having the desired end boiling point. The heavy ends of the crude gasoline are condensed in tower l6 and withdrawn through a into a, steam stripper column 22, in which and passed through a vapor line 23 into tower IS. The bottoms in column 22 are passed to storage through a'valved line 24. The overhead gaso-v line vapors are conducted from tower it through a vapor line 26 and condensed in condensers 28. The resulting condensate, which containsvwater because of the use of superheated steam in chamber 14 and column'22, is withdrawn separator29 in which the water is withdrawn through a line 30. Gasoline and gas are passed from separator 29 into a receiver 3|. Gas is vented from receiver 3| through a valved line 32 and gasoline passed to storage through a valved line 34. In conducting the fractionation in the tower IE, it is of particular advantage to return a portion of the finished gasoline from receiver 3| to the upper plates of the tower,'and M into a water separated and the quantity of air introduced through lines 42 into an injector 44 mounted in exhaust line 14.

this may be accomplished by the use of a-line 88 in which is mounted a pump 38.

The used clay separated out in the lower part of chamber 14 is removed therefrom by means of a rotary feed valve 48 and passed through a line a transfer line 48. Hot gas is supplied to the line '48 and injector 44 by a pump 48, and to this gas may be added preheated air supplied from a line 58 and forced by means of. a pump 52 through a line 54 and a preheating coil 55 into the line 46.

The ratio of contact clay to be revivified, to hot gas delivered to injector 44 may be adjusted by regulating the speed of rotary feed valve 48 in relation to the volume 'of gas passed into the injector. The proportionof clay should be properly adjusted so that it canbe readily car ried in suspension or conveyed by the gas mixture. The clay-gas mixture is forced,at a considerable velocity from the injector through the line 48 and passed through a (series of coil sections 58 perature of the mixture is preferably raisedin the first coil section we temperature at which oxidation starts or an exothermic reaction begins to take place. .throughout the remainder of the coil sections by the'heat of the furnace 60 and/or by the introduction of regulated quantities of oxygen or air through valved branch lines 82 which are supplied with air from line 54 through connecting line 54.

The temperature in the clay-gas mixture passing through the coil sections mounted in the furnace 88 is preferably controlled so that fusion of the clay particles is avoided and proper revivification effected. This is-accomplished by controlling the furnace temperature and particularly 62 and/or coil 55. The coil sections 58 are provided with thermocouples 65 which may be connected to recording instruments or to suitable automatic control apparatus to automatically of air introduced through regulate the quantity coil 58 and lines 82. The electrical mechanism for effecting such automatic control is common in various arts and therefore is not shown in detail.

If automatic control is desired, all that is necessary is to provide means for automatically regulating. the supply of air to-the various coil sections in response to variations in temperature in the coil sections as recorded by thermocouples 88. The clay-gas mixture is conducted from the last coil section 58,through a transfer line 88 into a centrifugal dust separator 18 in which the revivifled clay is separated from the gas. The revivifled clay is removed from separator 18 by means of a sealed rotary valve 12 similar to valve 48, while the hot gas is conducted through an The circulating gas introduced into injector 44 by pump 48 is drawn from exhaust line 14 through a' connecting line 18 while the excess gas is conducted from the line 14 into the lower part of a bag dust separator 18 in'which heat exchange coil 58 is mounted. The hot gases from line 14 pass in heat exchange with air conducted through coil 58.

The bag dust separator '18 is provided with a plurality of bag units 88 mounted above the coil 55. Each of these bag units includes a plurality of fabric bags 82 supported by a movable rack 84.-

The hot gas introduced from the pipe 14 naturally contains small amounts of very fine dust which is'filtered out in the bags 82 since the gas passes upwardly through the bags, leaving the dust inside. The cleaned gas is withdrawn v shown in Fig.1.

mounted in a furnace 58. The tem- This reaction is continued through individual valved conduits 88 into an exhaust line 88. in operation for a desired length of time, the outlet valve in the conduit 88 from that unit is closed and the valve in the outlet of another unit' After one set of bags has been lents as the revivifying partof the apparatus v The contact clay or other filtering medium from a process such as shownin Fig. 1, and which is to be revivifled, is introduced into the system through the rotary feed valve 48 and conducted through line 42 and injector into a stream of hot gas in line 48. As in Fig. 1, the spent gas produced in the system is passed into line 45 by means of pump 48. The mixture of hot gas andfinely divided filtering agent is discharged into the upper portion of a reaction tower 53 and allowed to settle therethrough while the reaction is being carried on. Air or oxygen is. supplied for the reviviflcation in tower. 58 by drawing air through pipe 58 and forcing it by means of a pump 51 through a valved line 54 and a heat exchanger 18 into a combustion chamber 55 through connecting lines 51, 58 and 8|. Gas from line 63 is burned in the lower part of the combustion chamber 55 in a burner 85 for the purpose of heating the air to the desired temperature. 59. The products of combustion from chamber 55, and introduced air, are mixed together and conducted through a valved line 81 into the line 48 in advance of the injector 44. Valved branch lines 59 are also provided for the introduction of the hot gaseous mixture into various parts of the reaction tower 58.

The control of the temperature of the gases passing through the line 81 may be accomplished by varyingthe amount of air introduced into the combustion chamber through the line 8| or by varying the preheat of the air thus introduced by directing any part of the air around the heat exchanger 19 through valved bypass line 58, 'or by varying the combustion of burner 55. In the normal operation of the apparatus shown in Fig. 2-the temperature in the tower 58 may be controlled in response to variations in the readings from thermocouples 85. The gas mixture passed into the injector 44 is preferably at a sumcient temperature to bring the contact clay up to ,the reaction temperature. Heat and oxygen are thereafter supplied to the reacting materials through the branch lines- 88. The revivifled clay or other contact material suspended in the gas is conducted from tower 58 through-thetransfer line 68 into a centrifugal separator 18 from which the reirivified clay is discharged through a rotary valve 12. The hot exhaust gases pass from the separator 18 througha valved line 14 and in heat exchange with the air passed through heat Air for the burner '85 is drawn from line.

exchanger 19. The recycle gas used in the procchanger 18 and/or an electrical precipitator may be used.

The finely divided clay and other materials to accuses with the process of the present invention usu be revivified in accordance ally contain small amounts of adsorbed hydrocarbons so that some oxygen is used up in the combustion of these materials during the early part of the revivificatlon operation, Gxygen is also used in the oxidation of adsorbed sulphur and in the oxidation of inorganic materials reduced by the oil treating process. The exhaust ewes from the process therefore contain a relatively larger proportion of nitrogen and small proportions of carbon dioxide and water vapor, of other gases such as sulphur dioxide are also present. I

The proportion or oil or hydrocarbon constituents left in the clay to be treated has an important eiiect on the reylvification operation and it is thereiore necessary to properly control the filming of the stay ash; is separated from the vapors in chamber ill, some combustible material should be left in the clay to aid in controlling the temperature and oxidation, but an excess sufficient to give a. iuslon temperature must be avoided. In some cases preheated air may be used without recirculating exhaust gases.

The process is applicable to the treatment of finely divided clay used in any process of oil refining, but it is to be understood that the clay before being introduced into the revivification operation is to be substantially free of heavy hydrocarbons. Clays used in the contactflitration of lubricating 011 stocks or preferably washed with a solvent such as gasoline, butane or propane prior to being revivlfied.

In describingthe process as carried out in the apparatus disclosed in the drawing reference has been moreparticularly made to the revivification of contact clays, but it is to be understood that the invention is equally applicable to the revivification of silicates, oxides ,and other inorganic refining agents or mixtures thereof. Metallic oxides either alone or when mixed with clays or silicates may be readily revivified bythe proces of the present invention, since the oxidation may be controlled accurately. In treating va-. rious types of materials, it is who understood that diil'erent temperatures may be required in order to convert the material into its original or desired form. Some clays or oxides or mixtures thereof may require relatively large amounts of oxygen and high or low temperatures for reviviflcation, whereas other materials may require only a relatively small amount of oxygen and relatively high orlow temperatures.

Having thus described the invention, what is claimed as new is:

1. The process of revivifying and reactivating 7 used solid inorganic refining agents, which comprises passing a rapidly flowing stream of, carrier gas through a heating zone in contact with an extensive heating surface, introducing into said stream entering said zone a stream of the finely divided agent to be revivified whereby said agent is passed with said gas through said heating zone, adding oxygen to said gas in said zone at a plurality of points to control the oxidation and revivification of the agent passing therethrough, discharging the stream of gas and agent into a separating zone in which the agent is precipitated from the gas, and returning a, part of the gas to the reaction zone as a carrier medium for the agent being conducted thereto.

2.- An apparatus for treating solid adsorbent,

whichcomprises a'mixer for intimately mixing 3 heating surface, vmeans for passing the mixture of gas and solid adsorbent through said heating element in a continuous stream, means for supplying an to said mixer, means for supplying air to said tubular element at a plurality oi points therealong to mix with the stream of gas and adsorbent passing therethrough, means for supplying heat to the material passing through said tubular element said means including means for externally heating the tubular heating element, and means for separating solid adsorbent from gas after passage of the mixture through said tubular heating element.

3. The apparatus as defined by claim 2 in which means is provided for recirculating through the apparatus a portion of the gas separated from the treated solid adsorbent.

4. The process oireilning solid treating agents,

which comprises passing a carrier gas in a rapidly flowing stream of restricted cross-section through a heating zone in contact withan extensive heat ing surface, introducing into and suspending in the said gas stream entering said-zone a stream of thefinely divided agent to be refined and passing said agent with said gas through and out of ,said heating zone, adding oxygen to said mixture of gas and suspended agent passing through said zone at a plurality of points to control the oxida .tlon and refining reactions taking place in said zone,-and discharging the stream of gas and agent from said heating zone into a separating zone in which the refined agent is separated from the gas.

heating surface to regulate and control the temperature to which the gas and agent mixture is heated, introducing oxygen into said gas mixture in said heating zone at a plurality oi points to control the refining of the agent passing therethrough, discharging the stream of gas and refined agent from said heating zone into a separating zone in the gas.

6. The process of refining solid treating agents which comprises passing a carrier gas containing free-oxygen in'a rapidly flowing stream through an externally heated coil of restricted cross-section relative to its length, introducing into and suspending in said gas streani passing to the inlet of said coil a stream of the finely divided treating agent to berefined and passing said agent in suspension in said gas stream through and out 01- said coil, controlling the application of heat to said coil to regulate and control the temperature to which the gas and agent mixture is heated therein tocontrol the refining of the agent passing therethrough, further aiding in the con trol of the refining of said agent passing through said coil by introducing oxygen into the mixture of gas and agent at an intermediate'point in said pnvrp G. BRANDT.

which the agent is separated from

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