US1829495A - Apparatus for the heat treatment of pulverulent materials - Google Patents

Description

J N. BAILEY Oct. 27, 1931.

APPARATUS FOR THE HEAT TREATMENT OF PULVERULENT MATERIALS Filed March 28, 1928 3 Sheets-Sheet 1 INVENTOR J, N. Bali leY WITNESS ATTORNEY Oct. 27, 1931. J N, BNLEY 1,829,495

APPARATUS FOR THE HEAT TREATMENT OF PULVERULENT MATERIALS Filed March 28, 1928 3 Sheets-Sheet 2 lwvemor LN-Bail eY J. N. BAILEY 1,829,495

APPARATUS FOR THE HEAT TREATMENT OF PULVERULENT MATERIALS Oct. 27, 1931.

Filed March 28, 1928 3 Sheets-Sheet 3 INVENTOR J. N.Bailey WITNESS BY CZ, ,ffi M ATTORNEY Patented Oct. 27, 1931 UNITED STATES PATENT OFFICE- JAMES NICOLSON BAILEY, OF GHORLTON-CUM-HARDY, ENGLAND, ASSIGNOR TO METROPOLITAN -VICKEBS ELECTRICAL COMPANY LIMITED, A COMPANY OF GREAT BRITAIN APPARATUS FOR. THE HEAT TREATMENT OF PULVERULENT IV'IATERIALS Application filed March 28, 1928, Serial No. 265,256, and in Great Britain March 29, 1927.

The invention relates to the heat treatment of pulverulent materials, and has for an object the provision of improved means for use for example in the carbonization of pulverized fuel.

A further object of the invention is the provision of an improved retort or more simple and compact form than those hitherto employed for this kind of heat treatment, whereby intimate contact between the solid particles and gaseous media is assured in a. uniform manner,.if desired with the aid of an improved feeding and distributing device for the material to be treated.

. Further objects of the invention include the provision of means for efiecting separation of the solid and volatile constituents of the contents of the retort at appropriate stages of the treatment, and an improved retort for tra tional distillation processes.

Various proposals have been made for the low temperature carbonization or distillation of coal, which entail bringing the coal in finely divided state into contact with a current of hot gases. the object being eventually to obtain powdered coke suitable for use in boiler furnaces and the like, and advantageously also various by-products, including gas for use in the carbonization of further coal by the same treatment. In one proposed apparatus the pulverized coal falls into a. stream of hot gas by which it is carbonized while being carried along in suspension through pipes terminating in an upwardly expanding chamber where carbonization is completed, the powdered coke being finally extracted from the gaseous products by means of a cyclone separator. The expansion chamber enables the heavier particles of coke to remain longer in contact with the hot gases and also effects relative movement between the particles and the gaseous stream constituting the fluid vehicle. In other apparatus the powdered coal is delivered into the upper end of vertical retorts in which it is carbonized while falling through rising currents of hot gas.

According to the present invention the heating of the p ulverulent material is effected in a retort comprising a vortex chamber in which the hot gases and the pulverized material are subjected to a violent whirling action whereby they are brought into intimate contact before beingpassed into a settling chamber, cyclone orother form of separating device to separate the treated pulverulent material from the fluid vehicle. Alternatively separation may be wholly or partly effected by one or more stages in the retort itself, which aflords particular advantages where the fractional distillation of pulverized fuel is concerned.

The invention also provides a retort and a device for feeding the pulverulent material into the retort, comprising a nozzle device through which said material is ejected in the desired direction by gas under pressure. A valve may be provided for controlling the supply of said material.

Thus the pulverulent material is thoroughly mixed with the hot gases and remains in Fig. 3 is a similar view showing a further modified form of retort according to the invention and Fig. 4: is a horizontal section on the line IVIV of Fig. 1.

Referring to Fig. 1, the vortex chamber 1 is formed of inverted pear-shape and has a number of gas inlet ports 2' arranged more or less tangentially as shown in Fig. 4 in the walls at the part of greatest diameter, the gas being supplied through an annulus 3 which embraces the chamber 1 externally. With this arrangement the axis of the vortex produced is vertical. Alternatively or in addition to the use of tangentially directed gas inlets for producing the vortex, vanes coming gas, as will be apparent. The pow-.

or deflectors may be arranged in any desired manner in the retort for directing the in- V dered material to, be treated is fedthrough ahopper 4 at the top of the retort chamber .1, and after treatment leaves together with the gasesby way of an outlet at the. bottom I or" the chamber.

The temperature of the hot gases entering. the vortex chamber through the ports 2"is dependent upon the character of material to be treatediand the results desired. Forexample, in thedistillation of powdered coal,

. the temperature may be approximately 1300" F. It is to be understood however that this i figure is not to be considered as limiting the invention.

, gas inlet tube 7 arranged concentrically within the conduit 5 for the powdered material. Nozzle-like outlets 8 through which said material is ejected bythe gas are formed between the upper portions of the cup 6 and the lower end of the conduit 5, and in the ''construction shown are providedwi'th guide vanes 9 curved to direct the outflowing'material more or less tangentiallv of the vortex,

and; assist the uniform distribution (see Fig, 4). p

"A valve member 10 of spherical form'is mounted upon the end of the compressed gas inlet tube 7 so that by verticaldisplacementof the latter the flow of pulveruent 'material fro-mthe hoppermay becontrolled.

Control may also be effected by throttling the simply of the compressed'gas entering the annulus 3.

In the apparatus shown the solid and gaseous contents of the retort leavetogether by way ofthe pipe 11 at the bottom, the extra ctionot' said contents being assisted by a fan orother suitable suction means it desired. The said'con'tents may be-delivered either directly or after'further treatment to a separator where they are treated in known manner for the separation of the spend ed solids, and v the gases delivered to plant'for the recovery of the more valuable by-products, as is customary. If desired however, separation of the solid and gaseous contents otthe retort may take place wholly or partly in the retort itself, for example by forming the lower portion of the retort chamber as a cyclone separator of usual type or by ar rangements such as hereinafter described.

7 If desired the powdered materialand gases may pass'through a numberofretort chambers insuccession, in some or all of which theymay be subjected to whirling in a vortex during carbomzatlon as abovestated, the

temperature being preferably-higher in successive retorts. -A retort of this character is shown in Fig. 2.

In Fig. 2 a number of retort chambers 12, 18, 1a of a substantially similar form to that shown and described above, arearranged coaxially one above the other, the bottom of one openingdirectly into the top of the next, and a supply hopper 15 and a feeding and distributing device 16 for-the pulverulent material are provided upon the uppermost chamber 12. Through the bottom of the lowermost chamherle, which tapers downwardly towards a lateral outl-et 17, pass a number of concentric tubes 18, 19, 20 which form the eduction pipes for the portions of the contents to be extracted from the central regions of the several chambers. The innermost tube 18 opens at the top adjacent the central region of the uppermost retort chamber 12 and v the remainin tubes 19, 20 similarly open respectively into the corresponding lower chambers 13, 14:. Below the retort the tubes 18,19,20 branch laterally and are'adapted for connection to separate pipes for conducting away the products abstracted through the several tubes. Immediately above the upper end o- f'each tube 18, 19, 20 is arranged a deflector or apron 21 of conical form, whilst other deflectors 22 are advantageously mounted immediately below. the waist-likej unctures between adjacent chambers. These deflectors are conveniently carried by the eduction tubes 19, 18 and in the uppermost chamber 12 upon l. C i) the bottom of the fuel distributing device 16.

In the operation of the retort above de scribed, for example, for the fractional distillation of powdered coal, according to the preferred arrangement, the particles of coal are fed into the uppermost retort chamber] 2 by fuel feeding means such as described? above, and mix with the hot gases, delivered through the lateral inlets 2 of said chamber. lnthis chamber the coal is heated to a certain degree, and some of the more volatile constituents may be driven off. Owing to the centriiugal action the heavier fuel particles tend to occupy positions nearer to the walls in the lower part of the chamber, while the lighter gases and vapours tend to occupy the central region of the vortex and may be drawn off through the eduction pipe 18. The

*heavier portions of the contents of the re-.

tort thus do not enter the eduction pipe but descend'into the next lower retortchamber T 13, at the entrance to which they are defiected somewhat outwardly by the conical deflector 22 and readily mix with the hot gases supplied through the lateral inlets2 of this gas ispreferably somewhat higher than that chamber. The temperature of the entering eral retort chambers. and gases may be removed from the last re- "of the retort chambers.

cessive chambers so that the pulverulent fuel particles leave the final chamber in the form of coke substantially free of volatile matter.

The gases or vapours removed by the several eduction pipes may be delivered to gas treating plant of known kind for the recovery of the by-products, and may incidentally serve to preheat the gas supplied to the sev- The powdered coke tort chamber and separated externally thereof in any suitable manner, or the centrifugal action in the last vortex chamber may be utilized to separate the coke finally from the products of distillation.

' 3i es. The latter ma also be arran ed to be adjustable in position so that the products may be removed from the appropriate regions Thus, in the construction shown in Fig. 2, the eduction pipes 19, 20 are vertically slidable, and may be ap propriately adjusted, for example, by the aid of rack and pinion means 23, 2a. Suitable glands 25 are provided to prevent gas leak- The arrangement is preferably such that separation of the powdered coke from the gases does not occur in the zone in a chamber immediately opposite to the tangential inlets of the hot gases but at a lower level where the chamber narrows towards the axis, the velocity of the gases and powdered coke being increased somewhat at this narrower region, where the centrifugal separating action is more pronounced. The deflectors aforesaid positioned immediately above the openings of the eductionpipes facilitate the separation and prevent the heavier particles from entering said pipes.

From the above description with reference to Figs. 1 and 2, it will be apparent that the invention may be carried out in various other forms without departing from the spirit or scope thereof. For example, a plurality of eduction pipes may be associated with a single retort chamber, the inlet openings of said pipes being located adjacent dilferent zones 7 in said chamber. Such a construction is illustrated in Fig. 3 which also shows gas inlet means arranged at different regions of the retort chamber.

Thus, referring to Fig. 3, a retort chamber 26 is provided with fuel feeding means 27,

which may be similar to that described above with reference to Fig. 1. Annular gas supply conduits 28,29 surround the chamber at different levels and communicate therewith by way of inlets 30. 31 disposed more or less tangentially in the walls of the chamber. Eduction conduits 32, 33 extend axially within the chamber 26 and open at different zones therein, said pipes being vertically adjustable substantially as previously described with reference to Fig. 2. Aprons 34, 35 are also providedabove the open ends'of the eduction conduits. By securing the apron 35, for example, to the end of conduit 33 and providing a sliding en agement thereof with conduit 32, the spacing of said apron above the end of conduit 33 is rendered invariable.

lVhile in the construction shown, the chamber 26 is associated with a further vortex chamber 36 therebeneath provided with gas inlet and eduction means 37, 38 respectively, and a final delivery outlet 39 for the heavier particles remaining after the treatment, it will be apparent that such further retort chamber may in some cases be dispensed with i or may be otherwise formed if desired without departing from the invention. Furthermore, while I have shown two sets of gas inlets. each adapted to assist in the creation of vortices in the retort chamber 26, it will be apparent that any desired number of sets of inlets may be provided for this purpose, the temperature of the entering through said inlets being preferably, but not necessarily, progressively higher in successively lower regions of the retort. For example, in a three-stage process the temperature of the gases entering the successive stages may be 600700 F. in the first, 1000 F. in the second and 1300 F. in the third.

It will. be understood that the gas employed for ejecting the pulverulent material into the first retort chamber or for treating said material in the several chambers may be gas recovered from the products of the treatment or'gas obtained from some other source or air or mixtures of these, according to the character or circumstances of the desired treatment. Also the powdered material may be subjected to preliminary heat treatment before entering the retort.

While the invention is more particularly applicable to the treatment of pulverized fuel it is not necessarily limited in this respect, but may be employed with advantage for roasting other powdered or granular materials, for example, powdered cement, prepared foodstulfs or the like.

lVhile I have shown my invention in a number of preferred forms it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications, without departing from the spirit thereof, and I desire, therefore,

that only such limitations shall be placed thereupon as are imposed by the prior'ar't or s as are specifically set forth in the appended claims:

1 I'claim'as my invention 1."In apparatus for the heattreatment of, pulverulent i material, a heating chamber, means for achnitting hot gases to the cham- V ber, means for. creating. a Vortex with said gases therein,.and means for feeding and distributingsaid pulverulent material therein, comprising a conduit extending towards the centre of the chamber and terminating I in a nozzle device'for the ejection of pulverulent material supplied through said conduit. 2-.In apparatus for the heat treatment of pulverulent material, a heating chamber,

means for admitting hot gases to the chamber, 'means for creatlng a vortex -w1th said gases "there1n,*and means for feeding and distributing'said pulverulent material therein, comrisin 'a conduit extendin within the chamber, a nozzle device mounted thereon and a tube extending within said conduit and 'n0zzle device. v V

1 3. In apparatus for the heat treatment of pulveru'lent material, a heating chamber,

means for admitting hot gases to the chamber, means for creatmg a vortex with said gasestherein, and means for feeding and distributing said pulverulent material there in, comprising a conduit extending within the chamber, a nozzle'device mounted there on, a tube extendingwithin said conduit and adjustable longitudinally therein, and valve distributing said pulverulent material therein, comprising a hopper disposed above the means. for adjusting the positions of said relatively high temperatures into the chamher so as to create a vortex therein, a gas eduction conduit having an inlet orifice disposed within thecentral portions of the chamber,

and means providing for movement of the inlet orifice so that the gas may be abstracted from any desired point in the chamber.

, 7, A retort for the fractional distillation of carbonaceous material in pulverulent form comprising a plurality of vortex chambers of roughly pear-shaped configuration, .ar-

ranged one above the other with the bottom of one openinginto the top of the next,.tangential gas inlet means disposed at the part of greatest diameter in each chamber for introducing thereinto gaseous media at relatively high temperatures, means for feeding the materials into the uppermost chamber in directions outwardly with respect tothe axis thereof, gas eduction pipes extending axially through the retort and opening adjacent the centers of the several chambers, means providing for the withdrawal of the residual products of distillation from the periphery of the lowermost chamber,-and means for de fleeting the entering material outwardly in each of the chambersbelow the uppermost chamber. 7 I "V In testimony whereof I have hereunto subscribed my name this second day of; March, 1928. I V I ,JAMES NICOLSON BAILEY.

chamber a vertical conduit connected at its upper end to said hopper and at its lower end "to a cup-shaped member within said chamber, a longitudinally movable tube within said conduit opening into said cup-shaped member, a valve member carried by said tube in said cup-shaped member, and means for directing material passed through said conduit and cup-shaped member in a direction upwardly and tangentially within the chamber. I a V V v 5. A retort comprising a pluralityof vortex chambers connected in series, means: for

. feeding pulverulent carbonaceous material .to

the first chamber of said series, substantially tangentially directed gas inlet means arranged perlpherally in each of said chambers for supplying gaseous media at relatively high temperatures, gas eduction conduits extending" into andopening adjacent the vcentral region of each chamber, and

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