US1750573A - Abrading and crushing machine - Google Patents

Description

March 11, 1930. P. L. cROwE ABRADING AND CRUSHING MACHINE Filed July 27, 1928 2 Sheets-Sheet 2 Mercia? IL. (fame Patented Mar. 11, 1930 UNITED STATES maize IAUL L. CROWE, OF BALTIMORE, MARYLAND ABRADING AND CRUSHING MACHINE App1ication filed July 27,

This invention relates to abrading and crushing machines, and especially to a machine for pulverizing and feeding coal.

The invention also relates to an electrically driven pulverizing machine which includes a peripheral motor.

One object of this invention is to provide a machine of this character which is of very simple and compact construction, which is very effectivein its operation, and thoroughly practical from the standpoint of the manufacturer and the user.

Other objects and important features are pointed out or implied in the following details of description, in connection with the accompanying drawings, in which:

Figure 1 is a central vertical sectional view of a machine constructed in accordance with this invention, the section being taken along the line 11 of Figure 2. v

Figure 2 is a horizontal sectional view, the section being taken along the line 2-2 of Figure 1.

Figure 3 is a fragmental detail view illustrating a somewhat modified form of the invention.

Figure 4 is an enlarged fragmental detail view showing a part of the ribbed and perforated hopper which forms a part of the grinding and crushing means.

Referring to these drawings in detail in which similar reference characters correspond to similar parts in the several views, the invention will now be described in detail as follows:

A 'main stationary frame is secured by bolts or other appropriate means to a floor F, and this main frame includes a base-plate 5 having thereon radially and upwardly extending supports 6,and an annular stator seat 7 on the'supports 6 and spaced therefrom, as indicated at 8, to provide for the passage of air for cooling the motor and the lower bearings, Which latter are indicated at 9. The bearings 9 include lower and upper bearing rings, and ball bearings between them, the lower bearing ring being seated on a central part of the plate 5, and surrounded by an annular wall 10.

The main frame also iI Cl ldBS a s t u 1923. Serial No. 295,754.

tially cylindrical part 11, a substantially horizontal part 12, and a substantially domelike part or arch 13, the latter including a centrally disposed bearing seat 14 in which is fitted a bearing ring15 for cooperation with ball bearings 16 and a rotary bearing ring 17 It should be understood that the main frame 5-6711121314, may be formed in any appropriate number of separable sections, for the purpose of assembling and disassembling, although it is here shown as an integral unit. The part 12 is provided with any appropriate number of outlet openings 12 which may be connected by tubes or other appropriate means (not shown) to a boiler, furnace or other fuel utilizing means.

The main frame also includes apertured inwardly extending cars 18 through which extend bolts 19 having adjusting nuts thereon, and these bolts also extend through openings in an annular inwardly extending flange 20 which is formed integrally with an inverted hollow truncated cone 21 which will hereinafter be referred to as the hopper. This hopper is open at its lower and upper ends, and is also provided with a number of annular series of lateral openings or perforations 22 which are outwardly flared or diverging, to prevent the comminuted or pulverized coal from lodging therein and choking these open ings. In this connection, it should be understood that the size of the openings 22. is greatly exaggerated in the drawings, an d that in practice, they are only a small fraction of an inch in diameter, to permit finely co1nminuted or pulverized coal to pass therethrough, while preventlng larger pieces or lumps of coal from passing therethrough. This hopper 21 is preferably formed of a thick heavy casting which has very considerable weight, so it will retain its position under ordinary circumstances, but will yield laterally, within predetermined limits, to prevent breakage of any of its parts, and of the abrading wheels which will presently be described. Moreover, this hopper is preferably formed with oneor more spiral helixes or ribs 23 which have relatively sharp inner edges, for a purpose which will presently be described,

The arched upright part 13 may have one or both sides open, as indicated at 24, which provides an inlet opening through which coal may be introduced into the hopper, through the open top of the latter.

A rotor is mounted to rest and ride upon the bearings 9 while the bearings 151617 assist in holding the rotor in its central operative position with respect to the main frame. More specifically, the rotor includes a disk provided with a central opening through which extends the lower end of a vertical shaft 26. A nut 27 (or other appropriate securing means) may be employed for recurring the shaft 26 in rigid relation to the disk 25, while a nut 28 on the top of the shaft 26 holds the bearing ring 17 in rigid relation therewith.

Any appropriate and desired number of abrading wheels 29 are secured on the shaft 26, so as to rotate with the latter, and to cooperate with the annularly ribbed hopper for abrading and crushing lumps of coal in the hopper. These wheels 29 are preferably of a uniform size and shape, and are preferably of much larger diameter at their middle parts than at their ends, so each of such abrading wheels presents an upwardly and laterally facing surface which abrades the lumps of coal which rest upon these surfaces while they rotate. It is not desirable to key these abrading wheels on the shaft, for it is not desirable toweaken them by the provision of key-ways therein, but it is desirable to prevent them from turning with respect to the shaft 26, and for this purpose, I provide washers 30 between them and between the upper one and the clamping nut 31 which is adjustable upward and downward on the shaft 26. These washers 30 may be of any appropriate material, such as vulcanite, fiber board, rubber, or any material or composition which is somewhat yielding and elastic. By means of these washers 30, the ends of the abrading wheels are protected from contact with one another, and at the same time elastically and frictionally clamped. Moreover, these relatively tough washers 30 reenforce the relatively brittle abrading wheels 29, so that even if one of them should split radially, its parts would be held in place by the elastic and frictional clamp which is provided by the cooperation of the nuts 27 and 31 and the washers 30. The rotor also ineludes an annular series of fan blades 32 which may be secured to the disk 25 by bolts 33 or other appropriate means. Each of these fan blades is preferably crescent-shaped in horizontal section, as shown in Figure 2.

The blades 32 are spaced from one another, to

provide air passages therebetween, and they extend from the disk 25 to within a slight distance of the part 12, so they effectively force the pulverized coal through openings 12, as will presently bev explained.

The rotor also includes an annular motor element or series of windings such as indicated at 34, surrounding the series of fan blades 32, and separated therefrom by a ring of appropriate material. The ring 35 may be secured to the disk 25 by any appropriate means, and the windings 34 may be secured to the ring 35 by any appropriate means.

An electric stator may properly be considered as including the stator seat 7, and an annular series of metal shoes 36, and electric windings 37 secured on the shoes 36, bolts 38 being employed for removably securing the shoes 36 in the stator seat. The motor (which comprises the windings 34 and 37) may be of any appropriate kind, and connected in any appropriate way with a source of electric energy (not shown); the novel feature of this invention not being dependentupon the particular form of motor (whether D. C. or A. (3.). However, an important feature of this invention is the provision of a motor of the peripheral type which has an exceedingly large diameter in proportion to the diameter of the abrading and crushing surfaces, so it is exceedingly powerful in comparison with the resistance to be overcome thereby.

In operating the device, either selected lumps or the general run of coal may be passed through the opening 24, into the hopper, and fed into the latter, either constantly or intermittently by any appropriate means (not shown); and now, when the motor is energized, it will cause the rotor to turn, so abrading wheels 29 and fan blades 32 rotate in unison with respect to the main frame and the hopper. The pulverized coal is immediately caused (by gravity, and by air-suction) to pass out through the openings 22, and thence upward through the spaces between the fan blades, and outward through the openings 12. In this connection, it should be understood that the fan blades rotate in the direction of the curved arrow shown in Figure 2. As the large lumps of coal rest upon the inclined or upwardly and laterally facing surfaces of the hopper and of the abrading wheels, the rotation of thelatter abrades the lumps of coal, and the abraded or powdered coal passes downward and outward through the openings 22, by the suction provided as previously described; and at the same time, the sizes of the lumps of coal are reduced, and tend to pass downward and to choke the machine by wedging between the hopper andthe abrading wheels, but this tendency is offset because of the lower side of each abrading wheel being approximately parallel With the inner surface of the hopper; or more specifically, the enlarged central part of each abrading Wheel is nearer the wall of the hopper than is its lower end. Therefore, when a lump of coal is reduced until it passes the enlarged central,- part of the upper abrading wheel 29, it falls onto the upper surface of the next lower abrading wheel, and no wedging action results from gravitation of the lumps of coal. On the other hand, because of the irregular shapes of the lumps of coal, they tend to wedge because of their tendency to be carried around by the abrading wheels. This latter wedging tendency is overcome by the annular ribs 23, which being upwardly inclined in the direction of rotation tend to lift the lumps of oal, and at the same time tend to cut and split the surfaces of the lumps by means of the relatively sharp edges of the ribs 23. Because of such inclination of the ribs 23, the lumps of coal are slightly raised, and then, because of their irregular shapes, they again fall onto the upper surfaces of the ribs and of the abrading wheels, thereby repeatedly dislodging the powdered coal from the lumps, the ribs 23 and the abrading wheels, by the impact of the falling lumps.

From the foregoing description, it will be seen that the invention includes a number of very important and practical features, including the elastic frictional clamping of the abrading wheels, the upwardly and laterally facing surfaces of the abrading wheels and the hopper, and the downwardly and laterally facing surfaces of the abrading wheels, by which the clogging or choking of the ma chine is effectively prevented.

Another important feature of this invention is the vertical adjustment of the hopper with respect to the grinding wheels, for properly positioning the lower end of the hopper with respect to the central part of the lowermost grinding wheel 29, for the purpose of preventing unpulverized pieces of coal from passing through the lower end of the hopper.

Referring now to the modified form shown in Figure 3, it will be seen that all parts are similar to those previously described, except the fan blades 3.4 which differ from the fan blades 32 by being upwardly and outwardly inclined, and being spaced from the rotorring 35.

Referring again to Figure 1, where it will beseen that the air-ga-p 39 communicates with the air space 8, under the disk 25, it will now be seen that the fan blades, while creating a suction and a draught through the hopper, also create a suction and a draught through the air-gap 39, thereby keeping the air-gap relatively cool and free from dust and pulverized coal.

Although I have described this embodiment of my invention very specifically, I do not intend to limit my patent protection to these exact details of construction and arrangement, for the invention is susceptible of numerous changes within the scope of the inventive ideas as implied and claimed.

What I claim as my invention is:

1. In a machine of the character described,

the combination of a hopper which is open at its upper and lower ends, a shaft extending upward through the lower and upper openings of the hopper and provided with an abrading element which is disposed in the lower end of the hopper and has various diameters, means to effect a relative rotary movement between said shaft and hopper, means to effect an air current thru said hopper, and means to effect a relative vertical adjustment between said shaft and hopper, for the purposes specified.

2. In a machine of the character described, the combination of a hopper having a downwardly and inwardly inclined wall and having a relatively large inlet or feed opening at its upper end, and a relatively small cir cular outlet opening at its lower end; an abrading unit including superposed abrading wheels each of which is outwardly flared from its top to its middle part, and thence inwardly inclined to its lower end, the said lower end of each abrading wheel being further from the wall of the hopper than is the said middle part, for the purpose specified; the relatively large middle part of one of saidwheels approximately closing said relatively small outlet opening when properly adjusted; means to effect a relative vertical adjustment between said hopper and abrading unit; and means to effect a relative rotary motion between the hopper and the said abrading unit.

In a machine of the character described, the combination of a hopper having a clownwardly and inwardly inclined wall, the hopper also having a relatively large opening at its upper end, for receiving lumps of coal, and a relatively small opening at its lower end, the hoppers inner surface being provided with a ridge that extends helically there-around; an abrading unit extending upward through the said relatively small lower opening and approximately closing the latter; and means to effect a relative rotary movement between said hopper and abrading unit in a proper direction for causing said ridge to raise the lumps of coal while abrading them, for the purpose specified.

4. A machine which includes a stationary unit and a rotary unit, the said stationary unit having bearings at its top and bottom parts and also having inlet and outlet openings, and a hopper adapted to receive lumps of coal through its inlet opening; the rotary unit including bearing elements to combine with said bearings of said stationary unit, the rotary unit also including an abrading unit which extends upward through said hopper, the rotary unit also including a series of fan-blades for creating an air currentthrough said hopper and outward through said outlet openings, and the rotary unit also including an annular actuating element surrounding said series of fan-blades; said statlonary unit being provided with means to cause said actuating element to impart a rotary movement to said rotary unit.

5. The structure defined by claim 4:, the said actuating element being an electric rotor, the said means being an electric stator which is spaced from said electric rotor by an airgap, and said stationary unit having air inlet openings under and in communication with said air-gap, whereby the electric rotor and stator are air-cooled in consequence of the air current caused by said fan-blades.

6. The structure defined by claim 4, the said fan blades being arranged in an annular series around said hopper, and said outlet openings of the stationary unit being directly over said fan-blades.

7 The structure defined by claim at, and means to adjust said hopper vertically with respect to said rotary unit.

In testimony whereof I affix my signature.

PAUL L. CRO'WE.

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