US1711964A - Paddle for impact type of pulverizers - Google Patents

Description

y 1929- w. w. PETTIB ONE 1,711,964

131mm,; FOR IMPACT TYPE OF PULVERIZERS Filed July 5, 1927 2 Sheets-Sheet 1 Inventor Peizibane A tlorney May. 7, 1929. w. w. PETTIBONE .PADDLE FOR IMPACT TYPE OF PULVERIZERS Filed July 5, 1927 2 Sheets-Sheet 2 Inventor W WPet bone Attorney Patented May 7, 1929.

UNITED STATES PATENT OFFICE- WALTER w. rn'r'rrnonn, or BIRMINGHAM, :ALABAMAQASSIGNORVTOV rm. EFFICIENCY ENGINEERING CGRIPORATION. A oonron-A'rion; or ALABAMA.

PADIDLE ron IMPACT TYPE orr'u rlvnniznns.

Application filed .Tuly 5,

My invention relates to a new and improved type of paddle impact type of pulverizers adapted for pulverizing coal, minerals, or chemicals, and relates to that class of pulverizers in which the material to be treated is passed successively through the desired number of stages in each o'fwhich it is subjected to an impact action by the rotating paddles, the liners, and theengag'ement of oneparticle against other particles under treatment.

Heretofore, in pulveri'zers of the type in question it has been the custom to mount the paddles upon the disk or other rotor by means of a pin or pins which intersected the base of the paddle and which were required to withstand the centrifugal strain on the paddle.

The object of my present invention. is to so design thepaddles and the rotor disk'upon which they are mounted that it is unnecessary to weaken the base of the paddle with a hole for a securing pin and in which the pin will co-act with a pair of shoulders on the paddle base so as to hold the paddle engaged in a non-radiaLslot in the periphery of the carrying disk. Asa result of this construction the paddle can be mounted very simply and yet with great strength and firmness on the disk and can be removed with great ease. I

My invention further comprises the novel details of construction and arrangements of parts which,in their preferred embodiment only, are illustrated in the accompanying 5 drawings which form a part of this specification, and'in which z- 1 Fig. 1 is a view illustrating inside elevation a typical impact pulverizer ofthe two stage type having the casing broken away to show the fan and two of the rotor disks in vertical cross-s'ection, the paddles mounted on the disks being shown in front elevation.

Fig. 2 is an enlarged detail viewin side elevation of one of the paddles shown mounted on a fragment of the rotor disk.

Fig. 3 is a cross-sectional view taken on the line III-III of Fig. 2 showing the paddle in rear elevation. Similar reference numerals reier'to similar parts throughout the drawings.

In the embodiment of my invention illus- 1927. SerialNo. 203,642.

trated, I have chosen for purposes of illustration, the type of iinpact pulverizer as especially adaptedfor the pulverizing ofcoal,

in which 4 indicatesa suitable feed mecha msm by means of which the coal is fed at a uniform rate into the initial treatment chamher 5, wherein is mounted a disk'dfast on a shaft 7 driven through a coupling 8 from the shaft 9 of a motor 10.. The shaft 7 turns in suitable bearings 11 and '12 in the- end walls 13 and 14. respectively, or thepulverizer casing. In the form shown, 'as'econd disk 6 is shown mounted in the second treatment chamber 5 both chambers being cylindrlcal in type-and the chamber 5 oi greater diameter than the chamber 5. The chambers i 5 and 5 are separated by a diaphragm 15 suitably mounted in the casing andproject ing inwardly from the peripheral wall ofthe chamber 5 a distance which brings its inner periphery wall within the periphery of-the disk 6. The disk 6 is made ofa larger diameter than the disk 6 to correspond with th e increased diameter ofthe chamber 5, and a diaphragm 15 defines the opening from the chamber 5 -into an air chamber 16, which has an annular valve 17 therein controlling a plurality of ports 18 and thereby regulat ing the volume of air admitted at this point. The diaphragm 15 is preferably designed so that its inner periphery stands at a greater distance from the shaft 7 than that of the diaphragm 15, but the diameter of cutter opening in diaphragm 15 is substantially less than the diameter of the disk 6. 'I The air chamber on its other side from the diaphragm 15 is'provided with an annular diaphragm wall 19, the inner periphery of which lies closer to the shaft than the inner periphery of the diaphragm 15 and leaves an annular outlet through which the treated products are borne on an air currentinto the fan chamber from which they are blown out by the fan 20 through the outlet connection 21 toany desired point of use.

" While I have defined structurally a suit-V able apparatus for the embodiment of my invention, it is nevertheless to be understood that that described presents merely the'suitable embodiment for itsuse and. may be va ried according to the material to be treated and the output desired and therefore may operate with a single stage or multiple stages.

My present invention is more particularly concerned with the construction of the paddles 22 which are suitably mounted on the r0- tor disks 6 and 6, and by reference to Figs. 2 and 3 the detail construction of these paddles and the preferred manner of mounting them on the disks will be better understood. In Fig. 2 it will be observed that the disk 6 is provided with a slot 23 projecting i11- wardly from its periphery at an acute angle in a radial line, this angle being preferably in the direction of the rotation of the disk, and the slot is also preferably of equal width throughout its length. An intermediate point of the underlying edge of the slot is intersected by an annular bnre or drill hole formed in the disk for the reception of a paddle lock pin 24, whichhole will lie preferably tangent to the edge of the slot. It of course will be understood that pins of different shape can be used, but the round pin shown is preferred. The pin is designed to project substantially on each side of the disk so as to engage the grooved outer ends of lugs 25 that project rearwardly from the base 26 of the paddle 22. This base is wider than the slot and at its intermediate portion is cut away and reduced to provide a web 27 shown in dotted lines Fig. 2, which will fit loosely in the slot 23 in the disk while the sides of the base will straddle the disk with a snug fit on each side, and the pin 24 will project substantially beyond the sides of the shoulders 25 to receive a cotter pin 28 in each end by means of which it is demountably held in operating position. Preferably, the web 27 stops short of the end of the base so that the latter will overlap the disk below the bottom of the slot, as appears more clearly in Fig. 3. Also, the front face of the paddle opposite the reduced web 27 is sloped inwardly at 29 to facilitate the casting or forging of the paddle with the design of the base described. It will be noted that the working or front surface of the paddle extends down below the periphery of the disk and is radially disposed and therefore at an acute angle to its base. The advantage of so constructing and mounting the paddle base lies in the fact that in operation the action of centrifugal forces will be distributed from the base to the slot walls of the disk and, through the shoulders 25, to the pin, and the latter will hold the paddle with its full shearing strength interlocked with the disk. The paddle will, therefore, not be weakened by reason of holes for any attaching pins or bolts, nor does the lock pin take the entire centrifugal strain on the paddle. There is another particular advantage arising from my manner of mounting the paddles, which is that I avoid the difliculty of accurate align ment of the holes in the paddle base and disk, which has heretofore been necessary, as in my construction the paddles will fit loosely in the slots 23 and will set themselves in working position when subjected to centrifugal force.

In Fig. 2 I have shown a somewhat exaggerated clearance between the web 27 of the paddle base and the forward edge of the slot 23 and I have not sought to show the paddle in the exact position that it will assume at work, it being contemplated that the paddle will rock further rearward and its base will rock forward and take a bearing against the inner end of the forward edge of the slot and against any suitable point either on the pin or rear edge of the slot.

Having mounted the paddles in the manner described, the operation of the pulverizer is that well understood by those skilled in the art, the fuel being carried through by an air draft and submitted to the action of the pulverizer impact rotors in the one or more stages employed and passing out with the air current to the point of use.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

1. In a pulverizer, a rotor disk having a plurality of paddle mounting slots inclined to a radial line, paddles having bases adapted to enter the slots, a lock element for-each paddle, and a lock shoulder comprising a lug formed on each paddle base extending alongside the disk and adapted to be engaged by its said'respective lock element to hold the paddle base in its respective slot.

2. A pulverizer. according to claim 1, in which the slots are inclined forwardly relative to a radial line- 3. Av pulverizer according to claim 1, in which the lock shoulder is formed on the rear face of the base of each paddle.

4. A pulverizer according to claim 1, in which the lock element is an axially extending pin mounted in the rotor adjacent to each paddle base.

5. In a pulverizer, a rotor disk having a plurality of non-radial peripheral slots, paddles having bases adapted to fit loosely in said slots and having rearwardly projecting lugs which straddle the disk, and demountable lock pins mounted in the disk and each adapted to engage the lugs of its respective paddle to lock same on the disk.

6. In a pulverizer, a rotor disk having a plurality of non-radial peripheral slots, paddles having bases reduced along their centers to fit loosely in said slots and to provide portions overhanging the front and rear edges of said slots, and locking pins adapted to engage the rearwardly projecting portions of the bases to lock them in position in their respective slots.

7. A pulverizer according to claim 6, in bases, and a demountable lock element on the which the paddle bases overlap the base of the rotor adapted to engage the lock shoulders slots. of each paddle and hold some in the slot, the 10 8. In a pulverizer, a rotor having a plupaddle base being wide enough to overlap the rality of non-radia1 slots, paddles having lock element.

bases adapted to be received in the slots, reztr- In testimony whereof I affix my signature. wvardly disposed lock shoulders on the paddle WALTER WV. PETTIBONE.

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