US1646752A - Pulverizer - Google Patents

Description

H. A. KIIMBER Oct. 25, 127.

PULVERIZER Filed Aug. 20, 1926 2 Sheets-Sheet 1 ATONEY I ll 1,646,752 Odo 25 9 1927' H. KEMBER PULVERI ZER Filed Aug. 20, 1926 2 Sheets-Sheet 2 ATTORNEY Patented a. 25, 1927.

PATENT OFFICE.

PULVERIZER.

Application filed August 20, 1926. Serial No. 130,371.

This invention relatesgenerally-to rotary devices for pulverizing or breaking up coal and similar materials to either powder-like or granular condition such as will enable it to pass through woven screens ofdifi'erent degrees of fineness of mesh, and is'designed to increase the efficiency and certainty of action of such apparatus.

More particularly the invention embodies certain improvements in apparatus of the above description in which aplurality of heaters or paddles are revolvedv in connected circular chambers formed in a cylindrical casing, the material to he pulverized being fed in at one end of said casing near the center thereof and the pulverized product expelled from the circumference of the chamber at the opposite end of said casing. To this end the invention comprises the provision, in apparatus of this type, of certain inclined beater blades or paddles and certain inclined stationary bafilcs between or adjacent successive sets of paddle wheels, by the interaction of which portions of the material being operated on are transferred from one chamber to another, or temporarily confined in one chamber, all in such a way that their pulverization is accomplished with certainty and with the least possible consumption of power.

The best form of apparatus at present known to me embodying my invention is illustrated in the accompanying two sheets of drawings in which Fig. l is a vertical axial section of the entire apparatus.

Fig. 2 is a detail plan view of a portion thereof with the upper part of the casing removed.

Fig. 3 is a detail side view with parts broken away of one rotary beater and one set of baffles, being essentially a side View of the parts shown in Fig. 2.

Fig. 4 is a diagrammatic development of r the preferred arrangement of heaters and battles, and

Fig. 5 is a section on line 55 of Fig. 1.

Throughout the drawings like reference characters indicate like parts. 1 is the cylindrical casing of the pulverizer to one end of which the coal or other material crushed preliminarily to standard size is fed through opening 2 in graduated quantities by asuitable feeding device 2. In this casing rotate sets of heaters, as 4, 4:, and 5, 5, carried by a revolving shaft 3, driven by coupling 3" from any suitable prime mover. Disposed around the cylindrical casing between or adjacent the different sets of heaters are stationary bafiies 6, 6, and 7 7. The finest material is ultimately sucked away from the heaters by fan 10 on shaft 3 and then blown out through the discharge passages 11.

In general character the above'described structure and mode of operation are not novel, and my invention consists in certain improvements in details of construction which produce a new mode of operation and improved results, and which I will now describe:

The first set of paddles 4 mounted on rotary disc 4, and forming the first beater encountered by the entering raw material, have their working faces slightly inclined toward the second set 5*, mounted on disc 5, and the space between the two sets is partly occupied by a plurality of short baffle plates (5, extending inwardly from the casing circumference. These baffle plates 6 have concave or sloping faces (as shown in Fig. 4) against which the material is thrown from heaters t, and are supported by riblike project-ions 6' from the interior of casing 1, or from a ring 6* mounted therein. The faces of these bafiles are not arranged exactly radially of the chamber but with a slight backward inclination to the radii thereof, as shown in Fig. 3.

The result of these features of construction is that when inclined paddles 4? revolve in the direction of the arrow in Fig. 3, a considerable portion of the material beaten up or knocked down by them is thrown against bafiles 6, the concave or sloping faces of which ensure the rebounding of the particles of material into the oath of the second set of paddles 5 by which they are consequentl struck with increased force due to the pad dles and particles travelling in opposite directions. Other portions of the material which have been broken down to a finer state of pulverization by being knocked back and forth between paddles *l and the hard lining rings 1 of easing 1 are dragged by the fan suction through the central open space 8 from the zone of the first heater 4, 4?, to that of the second one 5, 5.

Paddles 5, 5, have no inclination, and as the second set of short bafiles 7, 7, between said paddles 5 and the fan 10 have faces '7' curved or sloping toward paddles 5, all that portion of the material which is of large enough mesh to have individual solidity and momentum is thrown against these bafiies and by them turned back into the path of paddles 5. Thus the material is knocked down again and again until the continued impact and friction of paddles and ballles reduces it to a condition of such fineness and flufiiness that it ,has little weight and momentum relative to its area of surface exposed to air resistance. The, portion so pulverized is not thrown out centrifngally but is sucked out laterally by fan 10 through the central open space 9 and then blown out through discharge passages 11. The faces T of the batlies 7 may also be made straight, as shown in dotted lines in Fig. 4.

Among the advantages of the invention may be mentioned the efiicient action of the paddles 5, due to the fact that a large proportion of the particles struck by them are travelling in the opposite direction, having ricochetted from the inclined paddles 4* and concave or sloping inclined hafile faces 6; the prolonged beating received by the material from the second set of heaters 5 because of the feed back action of baffles 7, and the robust and durable character of the baflle systems resulting from their short, rib supported structure. This baffle construction at the same time does not clog up the air passage from inlet 2 to fan 10, because of the ample central openings 8 and 9 left by the-:e relatively short battles. It has been heretofore proposed to insert radial battle strips between sets of heaters, but as these cstendcd all the way to the central shaft they had to be made thin in order not to clog up the air passages, and because of this frail structure they soon broke or were out under the constant pounding and attrition experienced from the masses of flying coal or other material being treated. Also the inclination of the battle faces 6, toward the center of the casing, as shown in Fig. 3, contriluitcs to cliicienry in action as the material striking them is more apt to rebound into the path of the paddles 5 than to pack out against the annular lining 1*, as is the case when the batlles extend exactly radially of the chamber. thereby tending to form pockets with the enclosing easing into which pockets masses of material are thrown and thereafter hold to serve as cushions against which moving particles are thrown. thus absorbing power without producing useful results in the breaking up and grimling down of the materialbcing treated, which is mainly accomplished by direct contact with the paddles, batlles or casing walls.

This inclination of the beater fa es in effect serves to make them more nearly perpendicular to the line of travel of particles of material thrown against them by the heaters, and consequently the rebound of said particles is more apt to throw them back into the path of the heaters.

By the rebounding of the particles a heavier blow is struck, thereby reducing the materials more quickly and making it possible to get a large'capacity from a relatively small machine with the minimum of chambers and power.

Obviously various changes could be made in the angularity or curvature of the working surfaces used as above explained in carrying out my invention. and in the rela tive proportions of the various parts, without departing from the substantial novelty herein disclosed, or from the underlying principles of my invention, so long as the general arrangement of parts and mode of cooperation above set out, are retained.

Having described my invention, 1 claim:

1. In a rotary pulverizing apparatus the combination. with a casing containing a. generally circular chamber, of a series of sets of rotary heaters revolving in said chamher, and a set of stationary bafiles locatedin said chamber between said sets of heaters and having their faces against which the material is thrown sloped to facilitate the rebounding toward one set of heaters of the material thrown against them by another set. v

2. A combination such as defined in claim 1 in which the paddles of one of said sets of heaters are inclined laterally toward said battles; I

3. A. combination such as defined in claim 1 in which said haflle faces are concave.

4. A combination such as defined in claim 1 in which said bafiie faces are also inclined to the radii of the casing so as to be nearly perpendicular to the path of the particles thrown against them by said heaters.

55. In a rotary pulverizing apparatus comprising a casing. a set of rotary heaters and a fan both revolving in said casing upon a common axis, the combination, with said above recited elements, of short radial baffies set around the periphery of said casing between said heateirand fan, which battles have inclined faces on their sides adjacent. the beater, whereby the material thrown against them by said heater is returned tothe path of the heater paddles until it becomes fine enough to be sucked out by the fan through the central opening leftby the battles.

6. A combination such as described in claim 5 in which said inclined faces are curved concavely.

HARRY ARTHUR KIMBER.

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