US1959796A - Manufacture of portland cement - Google Patents

Description

Patented May 22, 1934 UNITED STATES MANUFACTURE OF PORTLAND CEMENT Martin Newcomer, Woodbridge, N. J., and Vincent Kay Newcomer, Independence, M0.

N Drawing. Application June 7, 1933, Serial No. 674,714

2 Claims.

In the manufacture of Portland cement the cement raw materials are passed through a rotary kiln in which they are subjected successively to a drying operation, a calcining operation and a 5 sintering operation under the influence of the intense heat of combustion of fuel which is supplied at the end of the kiln at whch the resulting clinker is discharged. In the succession of operations at some point in the sintering zone of the kiln the sintered material begins to adhere to the wall of the kiln and there is gradually built up on the wall of the kiln a ring of sintered material which eventually, if the formation is allowed to continue, reduces greatly the capacity 5 of the kiln. Such rings difier, under different conditions, in type, shape and chemical analysis. Sometimes they are hard, as in the case of what are called coal rings, which form near the discharge end of the kiln. Others may be long and somewhat soft and sticky, but at the same time tough. To restore the production capacity of the kiln the ring must be broken down and removed. To stop the kiln for this purpose involves production loss, increased fuel cost in reheating, and often damage to the refractory lining of the kiln. The usual practice, therefore, is to attempt to break down the ring by successive discharges into it of solid projectiles from a suitable type of gun, the intention being in that manner to cut gaps in the ring with the hope that eventually the remaining portions of the ring will break loose and move onward through the kiln to the point of discharge. This procedure is not only uncertain in results but consumes much time because many shots are necessary and the gunner must be protected from the intense heat at the firing point.

It has been the object of the present invention to make it possible to break down the ring more completely and expeditiously and therefore to avoid the serious production loss incident to the methods heretofore employed and in accordance with the invention the heat of the ring itself is taken advantage of to effect the explosion of a projectile, loaded with an explosive charge, fired into the ring from a suitable gun. It has been found that the ring can be broken down by a few explosions, the explosive charge within each projectile being so regulated as to break down the ring without injury to the refractory lining of the kiln. It will be obvious that the character of the explosive charge can be varied to suit conditions. It might be formed of a suitable explosive, such as black powder, for example, or it might even be formed of water, the heat of the ring being sufficient to set off the powder or to vaporize the water so quickly as to produce an explosive effect.

Each projectile is formed as a hollow shell of iron or brass or other suitable material in shape like a bullet and adapted to have enclosed within it a suitable quantity of the explosive employed. It is of such diameter as to permit it to be discharged from a gun of suitable calibre. The cavity of the projectile has enclosed within it the proper explosive charge, Whether of powder, or any other ordinary explosive, or water, or any other substance capable of exerting great gaseous pressure in the shell when heated to a temperature such as that attained by the ring, which may be from 2000 F. to 2750 F. The projectile is propelled by a charge sufficient only to drive it into the ring where it remains until the heat penetrates the shell and explodes the charge within it. The explosion of the shell has a shattering effect on the material of the ring. It will be understood that the time of flight of the projectile from the gun to the ring is so brief that the shell will not be raised, in the heated atmosphere of the kiln, to a degree sufficient to cause the shell to explode.

We claim as our invention:

1. The method of breaking down a ring of sintered material on the wall of a rotary cement kiln while the same is in a highly heated condition which consists in introducing an explosive charge within the substance of the ring and exploding the same by the heat of the ring.

2. The method of breaking down a ring of sintered material on the wall of a rotary cement kiln while the same is in a highly heated condition which consists in introducing into the substance of the ring a hollow body charged with a substance susceptible of being exploded by the heat of the ring.

MARTIN NEWCOMER. VINCENT KAY NEWCOMER.