US2456073A - Tube or ball mill with cooled trunnion - Google Patents

Description

, 14, 1948. R. c. Nr-:wHousE TUBE on BALL MILL wrm cooLEn Tamron Filed sept. 15

Patented Dec. 14, 1948 UNITED STATES OFFICE r2,456,073 p, y

TUBE on BALL MILL WITH oooL1 :D

TRUNN0N Ray C. Newhouse, Wauwatosm-Wisaassigner to Allis-Chalmers Manufacturing Company, Milwaulree, Wis., a corporation of'llelaware Application September 15, 11943, Serial'N.o'.,502,427

1 claim. (C1. gen-,67)-

This invention relates to ball mills for the comminution of materials in a heated condition.

-It has been previously known in the yart to grind heated materials both dry and in a liquid medium by tumbling them about with or without steel balls or other grinding media. It is also known `to cool the bearings of such mills in or der to keep bearing temperatures within a range for efficient operation.

An object of this invention is to provide an improved mill for heated materials with bearing trunnion structure spatially insulated from the mill end and from material feed and discharge conduits operating in contact with the heated materials and mediums.

Another object oi the invention is to provide for the circulation of gaseous cooling medium through the space between a mill end with its feed or discharge conduit and a bearing trunnion coaxially surrounding the material conduit.

It is a further object of this invention to provide a simple inexpensive and effective structure for maintaining an effective insulation of a ball mill bearing trunnion from parts of such mill operating in contact with heated materials which continuously pass through the bearing trunnion.

Specically the invention consists in a structure providing a clear space for the free ilow of air between a mill supporting bearing trunnion and mill end and the parts of the mill operating in continuous contact with heated materials being ground in the mill and passing through the bearing trunnions.

Other and still further objects may appear from the following description with reference to the accompanying drawing, in which:

Fig. l is a vertical longitudinal View of a ball mill according to the invention; and

Fig. 2 is a fragmentary top elevation showing a portion oi the edge of the heads and flange of the mill of Fig. l.

Rotating mill drum I is supported by bearing trunnions 2 on the heads 3. The bearing trunnions 2 rest in bearings 1l. Within the head 3 at the feed end of the mill and spaced from Chambers.-

-, The mill I may be provided with La ,suitable ...avisan head ils-.ifa is desired to since ne grinding space int@ Coarse ,and flle ,grinding At thesis@ are@ end .a positivedischarging head l@ vsimilar to that lscload in R. C.N.W house U. S. Patent 2,259,769 lis `arra'nged to dischargemaiefial from hefsrindinsspase ist@ the discharge conduit I1 which extends from the discharge end wall or liner IB closing the grinding space in coaXially spaced relation to bearing trunnion 2. The end liner I6 may be secured adjacent the said discharge head I4 and be spaced annularly from the end head 3. A stationary housing i8 receives the ground product and carries a valve I9 for a purpose disclosed in above cited U. S. Patent 2,259,769. Flanges l2 are provided on the ends of the mill drum for securing the end liners 6 and I6.

As shown in Fig. 2 the supporting heads 3 are bolted to flanges I2. The end liners 6 and I6 may be secured between anges I2 and heads 3, and may be spaced from heads 3 around their peripheries by a plurality oi arcuate bosses 2| on heads 3, in such a manner that recesses or openings 22 are formed to communicate with the annular space between said end liners 6 and I6 and supporting heads 3. Bolts 23 may be used to secure the end liners and plates to flanges I2.

In operation the mill I is arranged to be charged with a quantity of highly heated materials, as for instance, a mixture of coal or other solid material supplied through chute 9 and normally high viscosity uid such as bunker C fuel oil. This iiuid has been heated to a degree sufficient to lower its viscosity to permit ready flow as, for instance, 325 degrees Fahrenheit or more. The mixture is tumbled as in ordinary ball mill wet grinding and a uid suspension of line ground solids in oil is produced. The highly heated mixture flowing through the trunnons and drum oi the mill ordinarily would overheat the bearing trunnions and would, ultimately, causing bearing failure. The mill supporting heads and trunnions are spatially isolated from the highly heated end liners and trunnion liners or material conduits. This prevents direct conduction of heat to the bearing except through the limited and circuitous path olered by bosses 2I and heads 3.

Free llow of cooling media through the space between the end liners 6 and I6 and the corresponding structural heads 3, as shown by arrows in Fig. 1, is also provided for. This space being open to atmosphere, flow is induced by centrifugal force coupled with gravity draft due to contact of the air cooling uid with the highly heated parts 6, 1, I6 and I1.

The invention has at once lprovided for insulation and flow cooling medium between the surfaces of a ball mill which may be used for heated material and the structural end heads and hollow bearing trunnions.

While a particular embodiment of the invention has been illustrated and described it will be understood that such Vmodifications and equivalents as may readily occur to persons skilled in the art are included within the scope of the invention which is limited only bythe scope of the appended claim.

It is claimed and desired to secure by Letters Patent:

material treating container and said tubular vextension forming a material conduit opening into said container, means to support said container for rotation comprising a hollow trunnion of a diameter intermediate the diameter of said tubular extension and said drum shell in coax- 4 ially spaced relation to said tubular extension, said trunnion being physically connected in supporting relation to said container solely -by a structural end head axially spaced from said end Wall except adjacent to the outer periphery of said end Wall and passages opening radially outwardly from the space between said end wall and said structural end head to provide for free circulation of cooling fluid through the space between said end wall and said structural end head and hollow trunnion.

RAY C. NEWHOUSE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED 'STATES PATENTS Number Name Date 1,337,033 Ball Apr. 13, 1920 1,813,086 Sahmel July 7, 1931 1,819,093 Hardinge Aug. 18, 1931 1,937,788 Ross Dec. 5, 1933 2,206,477 Hardinge July 2, 1940 FOREIGN PATENTS Number Country Date 24,710 Denmark June 21, 1919 263,288 Great Britain Dec. 30, 1926

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