US2042494A - Baffled rotary kiln - Google Patents

Description

June 2, 1936. T. AvNsoE ET Al.

BAFFLED ROTARY KILN Filed March 9, 1934 2 Sheets-Sheet 1 Filed March 9, 1934 2 Sheets-Sheet 2 Patented June 2, 1936 UNITED STATES PATENT OFFICE BAH'LED ROTARY KILN 'umana amm. neuem, and Enmromeu,

Pelham, N. Y., assignors to International Cement Corporation, New York, N. Y., a corporation of Maine Application March 9, 1934, Serial N o. '114,742

13 Claims. (Cl. 263-22) This invention relates to the construction iofso. rotary kiln and more particularly-'tothe provision of battles-within the kiln.

' VIny the use of a rotary kiln for the burning of `Portland cement and similar products. very low 1 a large amount of heat is retained in the gases leaving the kiln. Furthermore the C0: carried along with the gases forms a blanket of CO: saturated air over the mix during calcination and retards the dissociation of the CaCOs.

Various attempts have been made to improve these conditions but because of the high temperatures encountered it has been diilicult or uneconomical to accomplish the desired improvement. f

It is an object of the present invention to provide an improved construction whereby the exposed surface of raw material is increased; the CO2 Aliberated during the calcining is agitated and removed from the surface of the raw material; the material being treated is cascaded directly through the hot gases; the length of the calcining zone and the radiating losses may be reduced; and the parts exposed to the heat may be maintained at a suiiiciently low temperature to assure low maintenance cost. It is also an object to provide improved means for supporting and cooling bailies'within a rotary kiln. Another object is to provide an improved arrangement for supplying cooling air to the baille. A further object is to provide an improved construction for retaining members within the kiln whereby the expansion and contraction of the kiln will be accommodated. Other objects will become apparent.

In describing the invention reference will be made to the drawings in which,

Figure 1 is a side elevation of the improved` ln'ln and cooling unit with portions of the kiln and cooler broken-away opposite the bailles.

Figure -2 is a fractional top plan view opposite one set of baies. y

Figure 3 is a section taken on the line 3-3 of Figure 1.

Figure 4 is a fractional diagrammatic view illustrating the means for retaining one end of the tubes in the shell of the kiln and lFigure 5 is a .similar .wiewloftheineans for retaining the other end of the tube. f-

Figure 6 is a diagrammatic section through vthe kiln illustrating the manner in which the bales are installed. 6

Figure 7 is a fractional side elevation of the kiln with the blowers removed and with portions cut away to illustrate the bailie construction and tubes, and f Figure 8 is a section taken on the line 8 8 of l0 Figure '7 a portion being broken away to illustrate the tubes.

In the drawings the numeral I0 designates a rotary kiln and .II a cooler. The kiln is heated by a burner at its lower end (not shown) or other 15 suitable means. The cooler is provided with means for supplying a current of air over the surface of the material therein (not shown). The kiln is rotated by the motor and gearing indicated at I2 and the cooler may be driven from 20 the kiln by a suitable gear or chain (not shown) or may be driven by a separate driving unit similar to that illustrated at I 2.

The kiln is provided with the usual lining I3 of refractory material and with a plurality of 25 baies I I spaced apart and positioned intermediate the ends of` the kiln, preferably in the calcining zone. The spaced baies I5, extend at right angles to the baflles I4 and are alternately positioned in relation to them. The baflies are made 30 up of a plurality of pipes or tubes I6 extending through and supporting a series of blocks I1. These blocks I1 are elongated blocks of refractory material each having a plurality of holes for the pipes I6 and being shaped to fit into each 35 other and to form a continuous baille. The pipes I6 are open to the air at their outer ends and at their inner ends are connected to a manifold communicating with an air blower. The pipes of the baliies I4 are connected to manifold I8 40 communicating with air blower I9 having an air intake 20 and the pipes of baille I5 are connected with the manifold 2I communicating with the air blower 22 having an intake 23. The air blower 22 is preferably positioned c iiametrically opposite 45 the blower I9 in order that the weight may be balanced around the circumference of the kiln.

The cooler II is also provided with baiiles 24 and 25 spaced apart and positioned at right angles to each other. These bailies are provided 50 with similar pipes, which pipes are open to the air at their outer ends and communicate at their inner ends with manifolds 26 and 2l, both of which manifolds communicate with a single air blower 28 having an air inlet 29. If preferred 55 this arrangement may be used on the kiln or the arrangement shown on the kiln may be used on the cooler.

In operating the kiln the raw mix is charged into the upper end of the inclined kiln I0 and as the kiln rotates the mix passes downwardly through the kiln toward the burning zone and the discharge end. Asv the material passes through the portion of the kiln having the bailles Il and I5 therein it is agitated and tumbled by the bailles and new surfaces are exposed t0 the hot gases from the burner. The mixture then passes on into the nal burning zone and the burned cement is discharged into the receiver for the cooler Il. As the' burned clinkers are fed through the cooler II they are agitated by the bailles 24 and 25 to give better contact with the cooling air introduced at the lower end of the cooler, which cooling air may be discharged in preheated condition from the upper end of the cooler and used as a. source of preheated air in the burners for the kiln or in some other manner.

Cooling air is forced through the pipes I6 by the blowers which rotate with the kiln and may be operated by a motor supplied with current through a collector ring 39 or by other suitable means.

Becauseof the expansion and contraction of the kiln upon heating and cooling, each pipe I6 is fixed to the shell' of the kiln or cooler at only one end. This is accomplished by a collar 30 threaded to an end of the pipe I6, which collar 30 is fixed to the shell by the bolts 3| projecting from the plate 32 which is riveted to the shell as illustrated at 33. The other end of each pipe I6 is retained by the tightly fitting collar 34 which is bolted to the plate 35 by means of the bolts 36, the plate 35 being riveted to the shell as illustrated at 31.

With this arrangement the expansion of the shell will cause the tightly fitting collars 34 to slip along the pipes I6 thus accommodating expansion and contraction of the shell.

The bailles may be Ainstalled as illustrated in Figure 6. A temporary scaffolding 33 may be inserted within the kiln and the blocks I1 may be laid out on the top of the scaffolding with their apertures registering with the oppositely positioned apertures in the shell. The pipes I6 may then be slipped through the apertures and the collars 30 may be bolted to the plate 32. 'Ihe collars 34 may then be applied to the other ends of the pipes I6 and bolted to the plate 35.

It is obvious that many variations may be made in the above apparatus and it is not intended to limit the invention to the particular arrangement -or details shown or described. For example, the

arrangement or numbers of the bailles may be varied or they may be placed at diil'erent angles to each other or all in the same plane or, if desired, only one section may be used. Also the means for cooling the bailles may be different or the means for supplying the cooling gas or liquid may be altered. The blowers and manifolds may be diilerently arranged and if desired the air or other cooling medium may be drawn through the pipes I6 by the blower or a pump instead ot being forced through them or in some cases sumcient cooling may be accomplished by a natural draft through the tubes, in which case the details of the invention may be utilized without using 'the blowers. The construction and means for supporting the baflles or the means for retaining the pipes may also be altered to suit particular conditions. If desired, the position of the baffles longitudinally of the kiln may be varied, although it is preferred to use the arrangement shown.

Theterms and expressions used in describing 5 and claiming the invention have been used in their descriptive senses and not as terms of limitation and it is intended that all equivalents of the terms used be included within the scope of the appended claims.

What we claim is:

1. A rotary cement kiln having an inlet at one end for cement materials and an inlet at the other end for fuel, comprising a shell having a plurality of transverse longitudinally extending bailles spaced from each other in the calcining zone ofv the kiln.

2. A rotary kiln comprising a shell having therein a plurality of transverse bailles extending longitudinally of the kiln and spaced from each other longitudinally of said kiln and angularly positioned relative to each other.

3. A rotary kiln comprising a cylindrical shell having therein a plurality of longitudinally spaced diametrically positioned baiiles angularly positioned relative to each other and extending longitudinally of the kiln.

4. A rotary kiln comprising a cylindrical :shell having therein a plurality of longitudinally spaced diametrically positioned baiiles at right angles to 30 each other and extending longitudinally of the kiln.

5. A rotary kiln comprising a shell and a transverse baille within the calcining zone thereof having a series of tubes extending through it and the 35 adjacent portion of the shell, and an air blower carried on said shell and adapted to force air through said tubes.

6. A rotary kiln comprising a shell, a plurality of bail'ies positioned in said shell with air conduits extending through them and the adjacent portions of the shell, and air ,blowers positioned at diametrically opposed positions on said shell and adapted to force air through said conduits.

7. A rotary kiln comprising a shell, a plurality of longitudinally spaced bames positioned at angles to each other in said shell and having air conduits adapted to conduct cooling currents of air through said bailles, and a plurality of air blowers positioned at diametrically opposed positions on said shell, and adapted to force air through said conduits.

8. A rotary kiln comprising a shell having a plurality of shelves therein extending longitudinally of the kiln and spaced from each other, each said shelf having means for conducting a cooling medium through it.

9. In a rotary kiln, a shell, a plurality of refractory partitions extending longitudinally of the kiln and arranged to serve as baliles for material moving circumterentially of the shell, said partitions being longitudinally spaced from each other with respect to the shell, and means to cool said partitions.

10. In a rotary kiln, a shell, a plurality of refractory partitions in the calcining zone of said shell extending longitudinally of the kiln and arranged to serve as bailles for material moving circumferentially of the shell, said partitions being longitudinally spaced and angularly disposed to each other with respect to the shell, and means to cool said partitions.

11. A rotary cement kiln comprising a shell having therein a plurality of transverse bailles extending longitudinally of the kiln and spaced from 7 each other longitudinally of said kiln and angularly positioned relative to each other, said bailies being positioned in the calcining zone .of the kiln.

l2. A rotary kiln comprising a shell, a plurality of partitions extending longitudinally of the kiln and arranged to serve as baiiies for material moving circumferentially of the shell, said partitions being longitudinally spaced from each other and comprising a plurality of hollow tubes encased in refractory material.

13. A rotary kiln comprising a shell,`a plurality of partitions extending longitudinally of the kiln and arranged to serve as baiies for material moving circumferentially of the shell, said partitions extending diametrically across the shell, being spaced longitudinally from each other, and comprising refractory material surrounding a plurality of pipes.

TH. AVNSOE. EJNAR POSSELT.l

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