US2609149A

US2609149A - Clinker cooling

Info

Publication number: US2609149A
Application number: US92483A
Authority: US
Inventors: Posselt Ejnar
Original assignee: Lone Star Cement Corp
Current assignee: Lone Star Cement Corp
Priority date: 1949-05-10
Filing date: 1949-05-10
Publication date: 1952-09-02
Anticipated expiration: 1969-09-02

Description

E. POSSELT CLINKER COOLING Sept. 2, 1952 5 Sheets-Sheet l Filed May l0, 1949 INVENTOR.

1f/VAR PSSELT wrw ATTORN EYS E. POSSELT CLINKER COOLING Sept. 2, 1952 3 SheetS-Sheet 2 Filed May l0, 1949 .EJ/VAR POSSEL 7' gw? Qmwi M HTTQR NEY5 Sept. 2, 1952 E. Fossi-:LT 2,509,149

CLINKER COOLING Filed May 1o, 1949 s sheets-sheet s 5/ f INVENToR.

BY .EJ/VAR POSSELT im LMS/wws Patented Sept. 2, 1952 CLINKER COOLlNG Ejnar Posselt, Pelham Manor, N. Y., assigner `to Lone Star Cement Corporation, New York, N. Y., va lcorporation of Maine Y Application May 1o, 1949, serial Na. 92,483

13 Claims.

rihis invention relates to a method oi and apparatus forA breaking and cooling the coarse portion of a .hot material having a substantial range of particle size, such for example, as the clinker of mixed size frequently produced in the manufacture of Portland cement. More particularly, the invention is concerned with a novel method and apparatus for separating large and incompletely cooled pieces of a furnace product following discharge from a cooling apparatus and simultaneously breaking and returning by impact at least apart of the broken material to the cooling operation.

Following the heat treatment of ores and rock products during sintering, roasting, smelting, calcining or clinkering, the continuous furnace or kiln discharge is usually .cooled by passage through a cooler in which the entire charge is subjected to the action of an air stream. Such cooling may be carried out in order to effect an "air quenching of the material by arapid temperature reduction, to eiect a recuperation of sensible heat, or both, or to .complete the cooling of material discharged .from a recuperator. Many furnace or kiln operations, either 'inherently, or because of the nature of the material composition, or due to irregular operation,.result in a product containing particles of widely varying sizes.. -In the normal cooling of such material, the relatively iine ymaterial is readily cooled due to its large surface area, and the larger particles are .often discharged from the cooling vapparatus containing substantial quantities of heat. When the equipment is operated to cool the larger pieces to a desired'temperature, abnormally large amounts of air, and coolers of excessive capacity, are required. Thehandling of thevlarger pieces invsubsequent plant operations, and vparticularly when only partially cooled, is burdensome and necessitates additional equpiment and supervision.

One commercial operation, in which such diiiiculties are encountered, is the manufacture of Fortland cement in arotary kiln, and the method of the present invention is particularly adapted to the 'treatment of cement clinker so produced. rihe components present in the raw materials mix fed to the kiln, :may be such thatv excessive clinkering takes place even during y:the best burning conditions, and the kiln `discifla-rge may contain a high proportion of clinker Iup to` 4 `to 6 in.V diameter, the desired size usually being .less than 1 to 2". In other instances, slightvariations in the kiln feed mix, lor in the burning conditions, willresultlin largegproportions of oversize clinker, even though normal operation on the same material gives a product of the desired small size. Furthermore, large sections of material present in the kiln as coating, or as rings, frequently break loose from the walls of the kiln and are discharged as slabs of substantial proportions.

Cement clinker discharged from a kiln .may be cooled in various types of rotary coolers, or with particular advantage may be air quenched and cooled by the methods and apparatus disclosed in such U. S. Patents as Norvig No. 2,041,142, Douglass Nos. 2,137,158 and 2,163,513, and Newhouse No.. 2,055,940, in all of which the hot clinker, `at a temperature in excess of 25,00D F., is cooled by contact with a stream of cooling air, and to which patents reference may be .had for a more complete .statement of the problems involved in vthe cooling of ,Portland cement clinker.

It has heretofore been proposed in Gaffney U. S. Patent No. 2,312,034 to remove from the cooling zone, the ne particles which have .been cooled to a desired degree prior to completion of the cooling operation. It has also been proposed to crush oversize clinker as it is .discharged from a cooler following a furnace or kiln, but such crushing exposes new hot surfaces which may be red or White hot and must again be cooled in order not to cause difficulty lin 4the conveying equipment which transports the crushed material to storage or to grinding mills. Such an additional cooling operation is a serious disadvantage, since :it usually involves a large .investment in equipment, particularly in view of the intermittent and variable quantity of crushed material to be treated. According to a more recent proposal, hot oversize clinker is separated from the cooler discharge, delivered to a conventional crushing mechanism, crushed to a desired size, elevated and conveyed to a point above the cooler. and reintroduced into the bed of partially cooled Aclinker at a predetermined point. Such an .arrangement is undesirably expensive .and mechanically complicated. Following the steps ofrcrushing and delivery tothe base .of an elevator, the hot broken material must be .ele-v vated and conveyed horizontally, and .introduced into the top -of the cooler. This requires costly heat .resistant crushing, elevating and conveying equipment, andthe -cost of maintenance, supervisionV .and power .are excessive. Furthermore, the arrangement ,requires additional iioor space and 'head room-wliichare vfrequently difficult to provide, and .special arrangements ,are necessary at the point of return to the cooler to avoid diversion of heated air.

The present invention is. accordingly, directed to the provision of a method for breaking and cooling the undesired oversize particles discharged from a cooler, which makes use of a principle of operation different from those heretofore employed,.and which-is not subject to the disadvantages of the prior systems. In the practice of the new method, I cool the mixed size furnace discharge to a degree sufficient to cool the fine particles to a desired temperature, separate the partially cooled large particles, break them by impact and, by the same impact, return a substantial proportion of the broken hot pieces to the initial cooling treatment. By this procedure. I am able to operate the cooling mechanism with maximum efficiency, and to reduce the large particles. by means of impact breaking equipment, to any size required for subsequent crushing and grinding operations, while, at the same time and by the use of the same breaking equipment, the hot broken pieces are projected to a zone in which they-Will be adequately cooled by contact with the partially cooled fine particles and by being subjected to the same cooling air required in the operation of the cooler.

In operating in accordance with the new method of my invention, I employ a novel form of clnker breaker. Throughout the specication and claims the word clnker is used generically to designate hot material which may result from any heat treatment such as sintering, calcining, roasting, smelting or nodulizing operations. The term furnace is used broadly to designate the heat treating equipment, preferably of the continuous discharge type, which may be in the form of a rotary or vertical kiln. The novel clnker breaker embodied in the invention may, with advantage, be employed in combination with a suitable cooler and size separator, to yield a product cooled to any desired degree and having any desired maximum particle size.

In order that my invention may be clearly understood, it will be described with reference to the accompanying drawings, in which:

Fig. 1 is a vertical diagrammatic view, partly in section, of a preferred form of apparatus for the practice of the new method, the apparatus as shown including an inclined reciprocating grate cooler;

Fig. 2 is an enlarged top plan view of one-half of the breaker structure of Fig. 1;

Fig. 3 is an enlarged vertical section showing details of construction of the breaker shown in plan in Fig.2;

Fig. 4 is a vertical View of an alternative type of breaker for practicing the new method; and

Fig. 5 is a vertical view of a second alternative type of breaker for practicing the new method.

Referring to Fig. 1, a clnker cooler lli, such as is disclosed in the referred to Douglass and Gaffney patents, is illustrated diagrammatically. An elongated chamber is divided into upper hot gas chamber 1, and lower plenum chamber 8, by an inclined surface in the form of a grate mechanism having alternate xed and movable grates, which supports and conveys a bed of material through the cooler. Hot material discharged from the kiln falls directly into the cooler through chute :9 and is distributedV horizontally by plate l0. The inclined grate structure, illustrated in detail section at its lower discharge end, comprises horizontal stationary grate plates Il, mounted on side frame Wear plates I2, and movable reciprocating plates I3, rigidly supported on movable side frames I4. These side frames, given a horizontal reciprocating motion by a driving mechanism indicated at l5, and supported on wheel mechanisms indicated at I6, cause the alternate movable gr-ates to agitate and advance the inclined bed of hot material through the cooler. Cooling air, supplied to plenum chamber 8 through duct I1, passes upwardly through the bed of material during its travel down the inclined support, and thence into the hot gas chamber 8 usually lined with protective refractory Walls I8. A desired proportion of heated air is directed to the kiln through chute 8, to be used as pre-heated secondary combustion air, and the remainder is vented to the atmosphere through stack I9. The cooling air passes vertically through perforations in the individual grate plates, and horizontally through the slight vertical spacings between adjacent grate plates. A limited amount of fine material passes between the grates and into the plenum chamber, and is periodically removed by opening a series of ports 20 in longitudinal housing 2l, in which a screw 22 advances the fine material, discharging it into a transverse pit 23.

The bed of cooled material containing hot oversize particles is advanced to a size separator, here shown asa grizzly 24. The individual grizzly bars 25, horizontally spaced to permit the passage of a desired size clinker, for example less than about 2", aresupported by transverse supports 26. The separating bars are preferably constructed, as shown in Fig. 3, to have a generally horizontal section' 21 and a steeply sloping section 28. The satisfactorily cooled undersize material passing through the grizzly bars falls into pit 23 and is removed by a belt conveyor 29 protected by guard plate 30. The hot oversize material is pushed across the horizontal section of the separator bars and slides down the steeply sloping section to a throat plate 3|. At this point it is broken up into smaller pieces by the impact of rotating swinging hammers 32, and simultaneously impelled lin an upwardly sloping direction.

The impact breaker mechanism, as illustrated in Figs. 2 and 3, comprises a plurality of horizontally spaced pairs of free swinging hammers 32, each hammer being suspended on a supporting pin `33, mounted in hammer discs 34. These are connected in pairs by means of hubs 35,110 a drive shaft 3B, which is rotatedby motor 31 through driving means 38. It will be noted that this device is similar in arrangement to a hammer mill but operating in the reverse direction. there being no crusing action between moving hammers and an anvil plate, as in the normal hammer mill. A Asmallfproportion of the shattered pieces of clnker `will'iind their way downwardly, and these are discharged through openings 39 into pit 23 to join the cooled fine material passing grizzly 24 and delivered by screw 22. Ihe entire'assembly is enclosed in housing 40 and made integral with the cooler walls, thus preventing the vescape'of fine 'material or the ingress of air except at the vdesired points.

A further proportion of the broken clnker is driven between.. the sloping grizzly bars 28 and falls into the pit with the separated fine fraction. At least a part, however, and with proper design ofequipment, a major part of the broken hot clnker, is impelled in' direct or deflected trajectories such that it is scatteredv across-the top of lthe side wall protection plates 4|.

the partially cooled bed of material advancing through the cooler, thus subjecting it to further cooling action. Depending on the eleavages, some particles of varying size will be impelled directly up the cooler, while others will be deflected from In order to increase the proportion and horizontal travel of the broken pieces entering the cooler, a sloping baille plate 42 may be positioned, as shown, above the grizzly. This plate serves the further purpose of providing increased breakage of some of the material striking it. To protect the refractory roof from wear, improve particle breakage, and increase deflection up the cooler, a plate 43 may be suspended from the brick roof. At times particles having a size close to that of thegrizzly bar spacing become wedged between the sloping bars 28, and are conveniently dislodged by grizzly cleaner arms 44, pivotally mounted on shaft 45 which is manually operated as needed.

In certain burning operations it is desirable to shift the location of the burning zone in the kiln, thereby causing a large ring of clinker to dro-p and be discharged to the cooler in the form of large slabs. In order that this abnormal load of coarse material will not be delivered to the breaker hammers at one time, a series of quadrant plates 45, mounted on manually operated shaft 41, are provided in order that the operator by raising them through the grizzly bars 21 may control the delivery of the excess of material to the breaker hammers.

Alternative types of mechanism which break the oversize hot clinker by impact and simultaneously return at least a part to the cooler are illustrated in Figs. 4 and 5. Both of these devices may be associated with a cooler in a manner similar to that illustrated in Figs. 1 to 3.

In Fig. 5, sloping grizzly bars 48, supported by

cross members

49 and 50 are shown positioned to receive clinker discharged from a reciprocating grate cooler of the type previously described. Clinker having a maximum size less than the grizzly bar spacings will be separated and fall into a pit 5l to be removed by an appropriate conveyor. The oversize slides down the grizzly bars and is stopped by the extensions 52 forming a grid which preferably has a slope complementary to the separating bars. Short vertical extensions 53 further insure that the oversize is held in the desired position to be broken. The breaker mechanism comprises a series of breaker armsor hammer blades 54 arranged to pass between each successive pair of grizzly bar extensions 52. These breaker blades are mounted on a transverse supporting shaft 55 by means of hubs 56, the blades being held in place in the hub in a machined recess. The hubs have suitably shaped projections 5l to permit actuation by cams 58 mounted on a cam drive shaft 59 attached to appropriate driving means. Each breaker arm is moved to its lowest position by a slowly rotating cam and placed under stress by a lcoil spring arrangement as shown. A spring guide rod 60, pivotally attached to the lower side of the hammer arm at 6l, and guided through a hole in the web of an I beam 82, provides support for an impeller spring 63 and a snubber spring 64. In operation, the cam slowly lowers the breaker arm to its point of maximum tension, and suddenly releases it causing it to pass through the space between the grizzly bar extensions and by impact break the large hot clinker held thereon, and at the same time project the broken pieces upwardly with trajectories such that a major portion will be distributed over the grate plates of the cooler. The snubber spring serves to limit the upward travel of the hammer arm to a desired maximum point. In Fig. 4 is illustrated an alternative spring structure for actuating the hammer arms. The particle size classifier and breaker arm structure are similar to those in Fig. 5 and equivalent parts have been identified by the ,same reference numerals. [In this alternative structure heavy duty leaf springs provide the impact force for the breaker arms. Such a spring 65, is rigidly mounted on the top of hub 5,6, the upward movement of its free end being limited by the horizontal roll'- er 66 Yduring compression, and its downward movement being stopped by roller 61 which serves as a snubber for the upward movement of the hammer arm. The limits of travel of the breaker blade and of the spring are shown in dotted lines. This structure has the advantage over the device of Fig. 5, in that the spring is farther removed from the hot zone, and thus is not as rapidly affected by the radiant heat from broken clinker. In both modiiications illustrated in Figs. a and 5, theY cams 5S are arranged on the drive shaft to produce a staggered release of the breaker arms.

In general it may be said that the novel apparatus of my invention comprises a separator which discharges suiiiciently cool fine sizes and delivers the hot oversize to a support on which it is broken by a properly placed impact means such as swing hammers or hammer blades, and by the impact the broken pieces are projected in a forward direction directly onto the moving bed. Such aV device when employed in combination with a cooler for furnace products of mixed particle size eliminates large particles and effects the cooling of all of the material to a desired temperature withmaximum efficiency by returning a major proportion of the hot broken pieces to the cooler.

. I claim: y

x l. A :clinker separator and breaker which comprises a separating zone having a separator including spaced grizzly bars for receiving partially cooled material of mixed particle size and for separating and discharging the suciently cooled fine sizes, means for receiving from the separator and for supporting the larger hot particles, means forl impacting separated larger particles with a force suiiicient to break them into smaller pieces, saidirnpacting means being constructed and arn ranged to return by the force of the impact at least a part of the broken pieces through the separating zone back to a point in advance of the separator, and a series of spaced arms fulcrumed on a supporting shaft below the grizzly bars and movable upwardly between the grizzly bars to dislodge clinker wedged between them.

2. A clinker separator and breaker which comprises a separating zone having a separator including spaced grizzly bars for receiving partialv ly cooled material of mixed particle size and for separating and discharging the sufficiently cooled fine sizes, means for receiving from the separator and for supporting the larger hot particles, means for impacting separated larger particles with a force suiiicient to break them into smaller pieces, said impacting means being constructed and arranged to return by the force of the im-V pact at least a part of the broken pieces through the separating zone back to a point in advance of the separator, and means for intercepting material above the grizzly bars to regulate the quantity of clinkerpassing thereover.

3. The clinker separator and breaker of claim 7 2 in which the means `for intercepting the material above the grizzly bars are arms projectable upwardly through the grizzly bars.

4. The method of treating hot furnace products of mixed particle size which comprises cooling the mixture in a cooling zone to produce a desired amount of cooling of the fine particles, separating the cooled iine particles, causing at least a part of the remaining larger particles to move into an impacting zone, impacting the larger particles in said impacting' zone with a force suicient to break them into smaller components, and reversing the direction of movement of at least some of said components and returning them in suspension backward into the cooling zone by the force of the impact to be subjected to further cooling.

5. The method of claim 4 in which the hot furnace products are formed into and are advanced through the cooling zone in a relatively thin bed.

6. The method of claim 5 in which the larger of the components resulting from the impacting are returned to the moving bed at points farther from the discharge end of the cooling zone than the smaller of such components, so that such larger components are subjected to cooling for a greater period of time.

7. The method of claim 5 which includes the further step of projecting the components resulting from the impacting onto a deflecting and impacting surface for further breakage and for deflection onto the moving bed.

8. Apparatus for treating hot materials of mixed particle size comprising a grate structure, means for passing a stream of cooling gas through material on said grate structure, a separator positioned to receive material discharged from the grate structure and to separate cooled ne particles of the material from larger and hotter particles, means for receiving and supporting separated larger and hotter particles in position to be impacted, means for impacting said separated larger and hott-er particles with a force sufncient to break them into smaller components, means for advancing the material over said grate structure in the form of a bed and along the separator, with the larger particles passing to the material receiving-and-supporting means, said impacting means being constructed and arranged to reverse the direction of movement of the components of the larger and hotter particles fed to it and to return them, -by the force of the impact, and in suspension, over the separator and onto the bed of material on the grate structure for further cooling.

9. The apparatus of claim 8 in which the means for receiving and supporting the larger and hotter particles is a generally horizontal plate, and in which the impacting means includes a rotatable shaft in spaced relation to the receiving and supporting plate, a plurality of spaced discsA rigidly mounted on the shaft, a plurality ofAfree-swinging hammer members pivotally mounted on pins supported by adjacent pairs of discs, with each-pair of discs supporting at least two balanced opposing hammers and driving means for rotating the shaft.

10. The apparatus of claim 8 in which the separator includes a plurality of substantially parallel grizzly bars positioned in spaced relationship, each of which has a generally horizontal section to receive material from the cooler and a steeply downwardly sloping section t0 deliver the separated larger and hotter particles to the means for receiving and supporting said particles in position to be impacted.

11. The apparatus of claim 8 which includes a series of arms fulcrumed below the grizzly bars and spaced on a supporting pivotal shaft for upward passage between the bars to dislodge material wedged between them.

l2. The apparatus of claim 8 in which the separator includes a plurality of substantially parallel grizzly bars, the means for receiving and supporting the larger hotter particles includes extensions of the grizzly bars and the impacting means includes breaker blades mounted to be passed between the extensions of the grizzly bars.

13. The apparatus of claim 12 which also includes a hub for each breaker blade fulcrumed on a blade-carrying shaft, leaf springs with bases rigidly mounted on the hubs, means for engaging the free ends of the springs to place them under tension and to limit their recoil, a drive shaft in spaced relation to the said blade-carrying shaft, driving means for rotating the drive shaft, and cam members spaced on the drive shaft to engage projections on the hubs and cooperatewith the springs to produce successive thrust and recoil movement of the blades.

EJNAR POSSELT.

D iile of this patent:

f UNITED STATES PATENTS