US2355784A

US2355784A - Pulverizer

Info

Publication number: US2355784A
Application number: US425833A
Authority: US
Inventors: Eugene J Dondlinger
Original assignee: Individual
Current assignee: Individual
Priority date: 1942-01-07
Filing date: 1942-01-07
Publication date: 1944-08-15
Anticipated expiration: 1961-08-15

Description

Augi- 1944- E. J. DONDLINGER 2,355,784

PULVERIZER.

Filed Jan. 7, 1942 2 Sheets-Sheet 1 Aug. 15, 1944. E. J. DONDLINGER 5 PULVERIZER Filed Jan. 7, 1942 2 Sheets-Sheet 2 INVENTOR.

Patented 'Aug. 15, 1944 UNITED STATES PATENT OFFICE PULVERIZER Eugene J. Dondlinger, Chicago, 111. Application January 7, 1942, Serial No. 425,833

v 10 Claims. (01. 83-11) Thi invention relates to pulverizers of the type suitable for pulverizing coal to be supplied in comminuted form to heating apparatus such as a furnace or boiler, or for use in brick kilns, core ovens or steam heating equipment.

One object of the invention is to provide an improved pulverizer in which th motor driven shaft is positioned vertically and has a blast fan combined with and built into the rotor of the pulverizing mechanism whereby the apparatus is rendered unusually compact and efllcient.

Another object of the invention is to provide a pulverizer of the hammermill type combined with suction apparatus which creates a flow of air for carrying of! the finely divided material and in which such air is led in a tortuous ath, which includes vanes or baifies, some of which are rotated with the pulverizlng mechanism and serve a to throw out of the air stream the coarser particles which require further pulverization.

It is also an object of the invention to provide a pulverizing apparatus having a comparatively simple casing structure adapted to be readily separated to give access to the pulverizing mechanism, and particularly to the liners which may require occasional renewal as a result of the wear to which they are subjected.

In general, it is'the object of the invention to provide an improved pulverizer of the type indicated, which shall be simple and economical in construction and eflicient in operation. Other objects and advantages will appear from the following description taken in conjunction with the accompanying drawings in which:

Figure 1 is a vertical sectional view taken substantially at the axis of the main shaft of the pulverizing mechanism and showing a machine embodying this invention.

Figure 2 is a horizontal section taken as indicated at line 2-2 on Figure 1.

Figure 3 is a horizontal section taken as indicated at line 33 onFig-ure 1 showing the auxiliary air fan or blower.

The pulverizer shown inthe drawings includes a base l adapted to be anchored to the floor, as by bolts 2, and formed to support the lower section 3 of the casing. This lower section houses the pulverizer mechanism and is surmounted by an upper section 4 containing a blower for supplying auxiliary air when the pulverizer is employed in connection with heating apparatus, so that the powdered coal delivered by the pulverizer requires additional air for complete combustion. Th casing 4 supports a driving motor 5 and encloses the drive pulley 6, the drive belt 1 and the driven pulley 8, which is secured to the upper end of the vertical shaft 9 disposed axially within the :asing. Roller bearings are shown at I for the lower end of the shaft, and ball bearings are provided at I l for the upper end of the shaft. These bearings are protected from the dust and gritof the pulverized material by suitable packing at l2, adjacent the lower hearing "I, and at l3, just below the upper bearings I I.

The pulverizing mechanism is of the hammermill type, including a rotor secured to the shaft 9 and comprising an upper plate 14 and a lower plate 15 between which the hammers l6 are carried on pivot pins IT. The rotor also includes a hollow hub structure composed of an inner sleeve I8 which fits the shaft 9 and is suitably keyed thereto, and an outer sleeve IS with an annular .wall 2!! connecting said sleeves at their upper ends. The space between the sleeves l8 and I9 is an annular chamber, open at the lower end except for a limited-number of spokes 2| extending substantially in the plane of the lower plate l5. This lower open end of the rotor hub communicates directly with an air intake chamber 22 which is formed between a horizontalpartition 23 and the horizontal bottom wall 24 of the pulverizing chamber. Said wall 24 has a central opening 25 directly opposite the lower open end of the rotor hub, and at one side the chamber 22 is provided with an air intake port 26 and an adjustable gate or cover 21 which is slidably shiftable to vary the effective area of the port and the resulting rate of air supply. The outer sleeve 19 or the rotor hub has a. plurality of outlet openings 28 disposed opposite the intervals between the hammers l6, and in these intervals there are secured between the upper plate I4 and lower plate l5 a plurality of fan blades 28 so that rotation of the rotor member operates to induce a flow of air from the port 26 through the chamber 22 into the hollow hub of the rotor and outwardly from the ports or openings 28 therein, and the centrifugal force of the rotation imparted to the air by blades 29 discharges the air forcibly past the hammers l6 and toward the impact lining 30 with which the hammers cooperate.

The pulverizlng chamber 3|, disposed between the bottom wall 24 and the top wall 32, communicates at one side with the feed tube 33, having a feed conveyor screw 34 therein, as shown in Figure 2, and the lining 30 is interrupted at 35 to provide an opening through which the material advanced by the screw 34 may be picked up by the hammers I 8 as they revolve past the opening 35. This material is thus carried around in the of said top wall.

pulverizing chamber and thrown against the lining 30 by centrifugal force acquired in its rotation, and is broken up and crushed by the impact of the hammers IS in this action. The finer particles are picked up by the air stream which travels in the general direction of the arrows in Figure 1 and escapes upwardly through an outlet port 36 in the top wall 32 of the pulverizing chamber and adjacent the central portion thereof.

The outlet 36 leads directly into the fan chamber 31, which encloses fan blades 38 secured to the shaft 9 and rotating therewith to operate as a centrifugal blower. This blower includes an air intake passage 39 having an adjustable intake valve or gate 40, said passage being disposed between the outer wall of the upper casing section 4 and the wall 4| of the fan chamber 31, and being upwardly open for communication with a space 42 between the partition 43 of the casing section 4 and the top wall 44 of the fan chamber.

The latter wall 44 has a central opening 45 by which the air is admitted to the fan chamber, whereupon it is picked up by the fan blades and thrown by centrifugal force through the outlet passage 46. This passage may be coupled to any suitable conduit leading to the combustion apparatus, such as a furnace or kiln in which the mixture or air and finely pulverized fuel is to be burned.

In the pulverizing chamber the air stream will at first pick up some of the coarser particles of coal which are not sufliciently reduced for satisfactory combustion, and to prevent these particles from passing out of the chamber 3| I provide a system of baiiies tending to arrest the movement of the coarse fuel particles without interfering with the continued flow'of air. Stationary bafiles 41 are disposed in substantially radial planes, depending from the top wall 32 of the pulverizing chamber, being in the form of plates bolted to suitable lugs 48 on the under side Additional baflies or blades 49 are secured in substantially radial position upstanding from the upper plate l4 of the rotor, and, as shown, the lower inner corners of the baflle plates 41 are notched at 50 to provide clearance for the passage of the upper outer corners of the baffles 49 as they rotate. It may be understood that the fixed baffles 41 are not necessarily disposed in strictly radial planes, and that experiment may determine the more effective angles for these plates, slightly away from the radial position, so that they shall function to arrest the swirling movement of the coal particles incident to the rotation imparted to them by the hammers I6 and by the general direction of the air stream through the pulverizing chamber. With their velocity thus reduced the coarser particles will tend to fall by gravity back to the pulverizing zone where they will be further treated and comminuted by the action of the hammers against the cooperating lining 30. The finer particles, however, will travel in a dust cloud along with the air stream past the surfaces of the baffies 4'! toward the outlet 36. If some of the coarser particles are carried past the baflie plates 47 they will encounter the rotating blades 43, and the centrifugal force thus imparted will operate to throw the particles clear of the air.

draw airthrough the intake 45 in the upper wall I of its housing but will also exert a pull on the air entering by way of the opening 36 in the wall 32.

The lining 30 of the pulverizing chamber may be made in sections, secured in place by screws or bolts 5| extending into or through the wall 3 of the lower casing section. The inner surfaces of these sections will be formed with vertically extending corrugations 30, as seen in Figure 2, and when these surfaces become worn the sections can be readily replaced upon removing the upper portion of the casing, including the wall 4 and the motor 5 superimposed thereon. As shown in Figure 2, the feed tube 33 includes an extension 33 beyond the opening 35 through which the coal normally enters the pulverizing chamber. This extension or pocket will tend to fill with coal as it is fed along the tube by the screw 34, but any large, hard lumps of foreign material, such as tramp iron, will be driven into the body of coal in the pocket 33 by the impact of the hammers IS in their travel past the opening 35, and the accumulation of such material can be removed from the pocket at intervals.

With the structure as described, the air stream delivered by the fan blades 29 of the rotor mingles immediately with the material under treatment by the hammers l6, and is thus disposed most fflciently for entraining the fine particles which are ready for delivery to the combustion apparatus; --and, at the same time, the baflie plates 41 and battle blades 49 are positioned to act immediately upon the material picked up in the air stream so as to eliminate therefrom the coarser particles which should not be transferred to the combustion zone without further pulverization. To further insure elimination of the coarser material the outlet 36 is surroundedbv a depending baiile ring 5| which deflects the air stream downward to a slight extent in the vicinity of the rotating vanes 49. As indicated in Figure 1, the incoming air stream passing upwardly through the central opening 25 in the bottom wall 24 of the pulverizing chamber may be allowed to divide so that a portion of the air flows outwardly under the lower flange IE only a short distance above the bottom wall and toward the peripheral lining 30. This air sweeps across any accumulation of coal lying on the bottom wall 24 so as to pick up all the finer material therefrom and carryit along upwardly toward the discharge opening at 36, thus preventing the undue accumulation of material in the bottom of the chamber where it might interfere with rotation of the rotor and with the free action of the hammers l6.

While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the invention, and that the same is not limited to the particular form herein shown and described, except in so far as indicated by the appended claims.

I claim as my invention:

1. In a pulverizer which includes a casing and a vertical shaft journaled for rotation therein, the combination of a pulverizing chamber, a rotor in said chamber including vertically spaced horizontal flanges with an inlet for air only leading to the space between said flanges, impact members swingably mounted in said space between the flanges, and fan blades disposed at intervals verized and an opening in its upper wall for around the shaft in said space, together with a separate passage through which material to be pulverized is admitted to the chamber.

2. In a pulverizer which includes a casing and a vertical shaft journaled for rotation' therein,

for admixture with material pulverized by the impact members, together with-means delivering -material to be pulverized directly into the peripheral portion of the chamber in the path of said, impact members.

3. In a ulverizer which includes a casing and a vertical shaft journaled for rotation therein, the combination of a pulverizing chamber, a rotor in said chamber comprising a hollow hub on the shaft with an upper plate and a lower plate extending horizontally therefrom in vertically i said stream.

spaced relation, said hub being closed at its upper end and open at its lower end, the interior of the hub opening into the space between said plates, impact members pivotally carried between said plates and extending outwardly beyond them, and fan blades disposed at intervals around the shaft in the space between the plates inducing a flow of air only into the openend of said hub and outwardly between the plates when the shaft rotates, together with means delivering material to be pulverized directly into the outer portion of said chamber in the path of said impact members.

4. In a pulverizer which includes a casing and a vertical shaft journaled for rotation therein, the combination of a pulverizing chamber, a rotor in said chamber comprising a hollow hub on the shaft with an upper plate and a lower plate extending horizontally therefrom in vertically spaced relation, said hub being closed at its upper end and open at its lower end, the interior of the hub opening intothe space between said plates, impact members pivotally carried between said plates and extending outwardly beyond them, and fan blades disposed at intervals around the shaft in the space between the plates inducing a flow of air only into the open end of said hub and out- -wardly between the plates when the shaft rotates, said pulverizing chamber having an opening through which material to be pulverized is admitted directly to the outer portion of the chamber in the path of the impact members and having a centrally disposed opening in its upper wall for discharge of air and any pulverized material entrained thereby.

5. In a pulverizer which includes a casing and a vertical shaft journaled for rotation therein,-

the combination of a pulverizing chamber, a rotor in said chamber including vertically spaced flanges with an inlet for air only leading to the space between said flanges, impact members mounted in said space between the flanges and traversing the outer portion of the chamber, and means operated by rotation of the shaft and producing an air blast outwardly between the flanges, said chamber having an opening in its peripheral portion admitting material to be puldischarge of air and material treated therein, together with approximately radial baiiles depending from said upper wall radially beyond the discharge opening and in the path of the air stream toward the discharge opening for arresting the coarser, solid particles and causing them to drop back into the pulverizing zone.

, 6. In a pulverizer which includes a casing and a vertical shaft iournaled for rotation therein, the combination of a pulverizing chamber, a rotor in said chamberincluding vertically spaced flanges with an inlet for air only leading to the space between said flanges, impact members mounted in said space between the flanges, and means operated by rotation of the shaft and producing an air blast outwardly between the flanges, said chamber having an inlet for material to be pulverized and having a centrally disposed opening in its upper wall for discharge of air and material treated thereby, together with baffles supported fixedly in the pulverizing chamber above the impact members radially beyond the discharge opening and in the path of the air stream flowing toward said discharge opening for removing the coarser particles from 7. In a pulverizer which includes a casing and a vertical shaft J'ournaled for rotation therein, the combination of a pulverizing chamber, a rotor in said chamber including vertically spaced flanges with an air inlet leading to the space between said, flanges, impact-members mounted in said space between the flanges, and means operated by rotation of the shaft and producing an air blast outwardly between the flanges, said chamber'having an opening in its upper wall for discharge of air and material treated thereby, together with approximately radial baiiles depending from said upper wall radially beyond the discharge opening and in the path of the air stream for arresting the coarser, solid particles and causing them to drop back into the pulverizing zone,'and radially disposed vanes carried by the rotor in a path closely adjacent said baflles to fling said .particles outwardly away from the discharge opening as they fall out of the air stream.

8. In a pulverizer which includes a casing and a vertical shaft journaled for rotation therein, the combination of a pulverizing chamber, a rotor in said chamber including vertically spaced flanges with an inlet for air only leading to said space between the flanges, impact members mounted in said space between the flanges, and means operated by rotation of the shaft and producing an air blast outwardly between the flanges, said chamber having an inlet for material to be pulverized and an opening in its upper wall for discharge of air and material treated thereby, together with a bafiie ring depending from the upper wall of the pulverizing chamber around its discharge opening, and radially disposed vanes carried by the upper side of the rotor directly below said ring.

9. In a pulverizer which includes a casing and a vertical shaft journaled for rotation therein, the combination of a pulverizing chamber, a rotor in said chamber including vertically spaced flanges with an air inlet leading to the space between said flanges, impact members mounted in said space between the flanges, and means operated by rotation of the shaft and producing an air blast outwardly between the flanges, said chamber having an opening in its upper wall for discharge of air and material treated thereby, together with approximately radial baflles depending from said upper wall radially beyond the discharge opening and in the path of the air stream for arresting the coarser, solid particles and causing them to drop back into the pulverizing zone, radially disposed vanes carried by the rotor in a path closely adjacent said baffles, and an annular baflle adjacent the discharge opening and above said vanes.

10. In a pulverizer which includes a casing and a vertical shaft journaled for rotation therein, the combination of a pulverizing chamber having a centrally disposed air inlet in its bottom wall, a rotor in said chamber including vertically spaced flanges with an air inlet leading from the inlet of the chamber to said space, impact memv hers mounted in said space between the flanges, and means operated by rotation of the shaft and producing an air blast outwardly between the flanges, said chamber having an opening in its upper wall for discharge of air and material treated thereby, together with a blower surmounting the pulverizing chamber with its fan carried on the shaft of the pulverizer, said discharge opening leading into the fan chamber of the blower, and an air inlet for additional air leading into the fan chamber of the blower with means for varying the capacity .of said inlet at will.

EUGENE J. DONDLINGER.