US1538192A - Apparatus for conditioning crushed material - Google Patents

Description

May 19, 1925. 1,538,192

v. G. LEAC H APPARATUS FOR CONDITIUNING CRUSHED MATERIAL Filed March 21, 1924 2 sheets-sheet 1 2/ f1. g j I Vzzzazz' Gazde @ach May 19, 1925.

V. G. LEACH APPARATUS FOR CONDITIONINQQRUSHED MATERIAL Filed March 21, 1924 2 Sl 1eets-Sheet 2 VE I Derzzozz (iarde e I {each Patented May 19,- 1 925.

VERNON canon-amen, or omcaeo, rumors. 1

APPARATUS roa connirronme caosnan murmur;

Application filed March 21, 1924. Serial Ito. 700,787.

To all whom it my camera:

Be it known that I, VERNON GARDE LEACH,

a citizen of the United States, and a resi- I dent of the city of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in an A paratus for Conditioning Crushed Material; and I do hereby declare that the following is a full, clear, and exact descripaccompanyin tion of the same, reference being had to the drawings, and to the numerals of re erence marked thereon, which form a part of this specification.

This invention relates to an apparatus for-- conditioning granular or pulve'rulent materiall more particularly crushed or powdered O08.

not only for the reason that the efficiency of combustion is increasedbut also because moisture in coal creates difficulties in conveying, handling, and storing.

Further, in pulverizing crushed. or granu- I lar coal,more power is required if the coal is moist.

In addition to the desirability of low moisture content, itis advantageous to pass thecoarsely crushed coal to the pulverizers cold. One' of the great difliculties with all dryers on the market today isthe fact that the coal is introduced into the pulverizer while hot. When hot, the particles of coal tend to adhere to each other and clog the pulverizer, transportation pipe lines, etc. Further, when a warm lump of coal is .broken it steams as the result of the .va-

porization of the moisture contained in the interior of the lump. This steam or water ,vapor then condenses on the cold walls of the pulverizer, ipe line and so forthand causes the pow ered coal to adhere thereto. If, hgyever, the lump is cooled to at mospheric temperature this 7 vaporization does not occur.. Hence it is desirable not only to dry the coal but also to cool it nearly to atmospheric temperature before introducin it into the pulverizer. The coal shoul' therefore,be conditioned rather than merely dried.

Various methods and apparatus have'been proposed for ,drying coal. -Thus it has been proposed to use the heat from waste or chimney gases to dry the coal. This involvesnot only-diificulties in controllin the heat used but also occasions loss of V0 atile constituents,*danger of ignition of the pdwdered fuel and so forth. i

siderable proportion of water-vapor so that when cooled to atmospheric temperature dew will be deposited withthe resultthat if powdered coal dried by such ases is passed through a pipe line expose to the atmosphere dewlwill deposit on the interior of the pipe which dew will cause the coal to adhere tothe side of the pipe and"olog also-to reduce the moisture content'of the air or gas entrained in the crushed mass below the dew point. This involves first Powdered coal should" be dry when used much water. Most'oi the water may be re- 1 moved by air drying at ordinary temperatures, while the remainder (usually some 2 'to 3' percent) is almost completely lost at 105 degreescentigrade.

The moisture which air or other gases can take up is a function of temperature.

Waste 1 or chimney gases contain a con- Atmospheric air is rarely saturated but its capacity to take up additional moisture is small. If the air s heated, its capacity to absorb water vapor is reatly increased.

If heated air is passed through a mass of coal, the air takes up a part at least of the moisture of the latter and simultaneously heats up the coal. It, therefore, air at atmospheric temperature is passed throu 11 such heatedcoal the air is warmed there y andits moisture absorbing power is increased.

Very-eflicientdr ying may be obtained by first passing heated air through the mass to eliminate a part of the moisture and simultanecusly heat the coal and then passing air at atmospheric temperature throu h the heated coalto utilize the heat of t e latter-in warmingthe' air sothat it is capable of readily absorbing the moisture in the coal in the first stage of the process or for other useful purposes such as airfor combustion.

.The passage of air at atmospheric temperature through the crushed coal sweeps 15 crushed coal.

Figure 1.

out of the interstices in the latter any air having a high moisture content so that the air entrained in the final'product will not deposit dew in any subsequent operation. In this condition both the crushed coal-itself and the air surrounding the particles and entrained therein-are in substantial equilibrium with the prevailing atmospheric conditions so far astheir temperature and moisture contents are concerned,

It is an object-of the present invention, therefore, to provide efificient, simple and readily-controlled "means for condltioning granular or pulverulent material such as Other and further important objects of this invention will be apparent from the disclosures in the accompanying drawings and the following specification.

The invention (in a preferred form) is I illustrated in the drawings and hereinafter more fully described. v

On the drawings:

Figure 1 is a vertlcal section through an 25 apparatus constructed in accordance with the resent invention.

Figure 2 is a section onsthe line 2-2 of Figure 1. a

Figure 3 is a section on the line 3-3 of Figure 4 is a vertical section through a. mod'fied form of ap aratus.

As shown on the rawinfis: s The form of apparatus s own in Figures 1, 2 and 3 comprisesacasing provided w1th an air inlet duct 11 and air dischargeduct 12 and a partition 13 adapted to prevent air passing directly from the duct 11 to the duct 12. The lower chamber formed by the partition 13 is in communication with 5 through I the series of bars 18 arrangedstep-wise I the eccentric the intake 14 of a centrifu 1 fan 15. The discharge duct 16 of this i an is connected with the upper chamber of the casing.

Extending obliquely across the casing and for the material to be treated. This su port may conveniently be constructed on t e r principle of one or othe nof the well-known forms of mechanical stokers comprisingf a or simultaneous movement by an eccentric 19.

. The crushed material 20 is fed onto this inclined support from a hopper 21 by means of a plunger 22 which is 'reciprocated by 19. A gate 23 at the front of the hop or is provided to adjust. the amount of e1 delivered to the support 17.

the end of the support 17.

Below' the artition 13 are arranged means for heating the air which is drawn throu h the bed: of material from the duct ese means may be varied suit vapartition 13 is a support 17 rying conditions. In man cases it will be convenient to use heat exc angers, suchfor example as a series of coils 25 heated by steam, waste gases, etc. By this means the air discharged by the fan 15 and forced upwardl through the bed of material into the discharge duct 12 is heated first by the warm bed of material and second by the steam coils.

The passage of air directly from the duct 11 to the duct 12 over the layer of material passing down the support 17 is prevented by means of a series of shoes 26 pivotally supported by links 27. These shoes ride on the upper face of the layer of material and may rise and fall with it. is

n the form of construction shown in Fi ure 4, the air is not passed twice throug the bed of material with an intermediate heating operation.

In this case there are two inlet ducts 30 and 31 leading to the casing 32, through which air may be passed by fans or blowers not shown. Where air is introduced throu h both ducts the upper duct 30 contains eat exchanging means such for example as a steam coil 33 for heatin the air flowing therethrough. If waste hot gases are introduced through the duct 30, the heating means may The air which passes throu h t e lower duct may to advantage be use in combustion, in view of the heatit contains.

shown in Figures 1 to 3.

In the present art of furnace construction it has been found desirable to use hollow furnace wall's, air cooled, largely for their be omitted.

. In other respects, the construction is similar to that rotection. Such air is used to support comsubstantial depth over said support, and

means for passing first a current of'heated gas and then a current of unheated gas through the material as it passes oversaid support. 'At the lower end of the support a screw or other suitable conveyor 24 is. rovided' for, discharging the material as it rops ofi 2. An apparatus for conditioning crushed material, comprising a support, means for passing a continuous layer of material of substantial depth over said sup ort, means for passing a current of u eated gas ilshrough the material as it passes over the. 1 ast art of said support :m'eans for heating t e current of gas after it has passed tioning I through the material and means for repass ing the gas so heated through thematerial as it passes over the first part of said support'.-

3. An apparatus for conditioning crushed material comprising a casing, a support within said casin means for passing a continuous layer 0 depth over said support, a partition within the casing intermediate the ends of said support, a movable closure member adapted to rest upon said layer and rise and fall therewith to prevent the passage of gases between the lowerjedge of said partition and said layer of material.

material of substantial ends of said support, and means for pass-.

ing currents of gases throu h said stream of materialp on either side 0 said partition.

In testimony whereof I have hereunto subscribed my name in the presence of two 26 subscribing witnesses.

Witnesses:

Rmsmu: Ems, Hmrwnsoo'rr Wanna PVERNONIGARDE LEAOHJ

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