US551390A - lande - Google Patents

Description

2 Sheets-Sheet 1'.

(No Modal.)

P. M. LANDE GEMENT KILN.

Patented Dec. 17, 1895.

(No Model.) 2 Sheets-Sheet 2. F. M. LANDE. CEMENT KILN.

No 551,390. Patented Dec. 17, 1895.

ANDREW E.GRAHlNvPHOTO-UTNO.WASN1NGTUK.D.C.

Fries.

PATENT FREDERIO M. LANDE,

OF NEIV YORK, N. Y.

CEMENT-KILN.

SPECIFICATION forming part of Letters Patent No. 551,390, dated December 1895- Applicatidi filed February 16, 1895. Serial No. 538,721. (No model.)

To aZZ whom it may concern.-

Be it known that I, FREDERIC M. LANDE, a citizen of the United States of America, residing at New York, county and State of New York, have invented certain new and useful Improvements in Cement-Kilns, of which the following is a specification.

My invention relates to kilns for the burning of Portland cement and the calcination of limestone and gypsum.

The two general methods of burning Portland cement are known as the draw and rotary kiln methods. In the first there is not only less of heat but loss of material in the underburned and overburned elinkers, one required to be reburned, the other thrown away. Moreover, in the ordinary vertical kilns powdered material cannot be burned. In the rotary kilns there is great loss of heat, not only through the stack but by reason of the admission of an excess of cold air at the discharge end of the cylinder. Again, such kilns require frequent relining and other repairs and are expensive to construct and operate, as each requires a separate engine to rotate it.

In the kiln here presented I can pass the materials continuously and obviate the objections to the methods just described.

The accompanying drawings illustrate the construction of the device to attain the desired results.

In, the drawings, Figure 1 is a vertical section of the kiln, showing the combustionchamber and conical receiving-base; Fig. 2, a section on line Y Y, Fig. 1, showing the adjustable shelves and means of support therefor; Fig. 3, a plan view of the kiln; Fig. 4, a detail sectional view of the upper shelves and supports; Fig. 5, a detail plan view of one of the shelves; Fig. 6, a detail side view of same, and Fig. 7 an end section of the feedin g apparatus.

The kiln maybe built of any suitable height and width, depending on the quantity of material to be passed through in a given time. The outer shell A is preferably of hardburned brick, the lining consisting of one or brioks e e", the bricks e being placed below the bricks e on opposite sides, as shown in Fig. 2. Inclined to the side walls and supported by these ledge-bricks are the deflect ing shelves D D. These shelves consist of fire-clay slabs cut away at one side so as to leave lugs d, Fig. 5, which rest on the supporting-ledges, the openings 0 formin g a passage tor the descent of the clinkers and the ascent of the gases. One under edge of the slab is made V-shaped to engage the edge of the supportingbrick, the opposite edge resting flat on the opposite lower brick. The shelves in the upper half of the kiln are inclined at an angle of about forty'iive degrees, the lower shelves being inclined at an angle of about thirty degrees.

The raw material when it is first fed into the kiln is sharp and angular, and there is a tendency to adhere to the slash. Therefore, to insure a more rapid descent on the upper shelves, such shelves are given a greater angle of inclination. As the material approaches calcination and clinkers are formed, the surfaces of the clinkers become rounded, there is less friction and retardation on the shelves, and they begin to descend rapidly. New, in order that the full effect of the heat may be obtained, the lower shelves (about one-half of the series) are given a decreased angle of inclination and thus increase the time of transit. This arrangement of shelves will meet the burning requirements for ordinary quick-setting Portland low in lime. If, however, a high-limed slow-settin g Portland is wanted, the material requires a longer burning period in order to produce a perfect clinker. In this case, in order to retard the downward movement of the clinkers, the shelves are given a decreased angle of inclination. This is accomplished by removing the bricks e and dropping the upper ends of the shelves so as to rest 011 the bricks c. This, it will be noted, gives an adj ustability to the shelves and an adaptability of the kiln to high or low limed cements. The formed clinkcrs fall to a cone-shaped bottom 13, where they are permitted to remain a suflicient time and yield up their heat to outside air and thus give an increased volume of hot gases to assist in the bu rning. After remaining at the bars a suitable time the clinkers are drawn through doors 0. The kiln is stepped at A to form a combustion-chamber for the gases given off by the petroleum or other gaseous fuel-burners 1), arranged above the grates a. The air-chamber A has an air-inlet a and an air-outlet to the clinker-chamber by means of the damper a At certain stages of the burning when the clinker-chamber has become partially filled the fuel may be reduced and air admitted to combine with the heated gases in this clinker-chamber, thus minimizing the consumption of fuel. This cannot be done in the rotary kiln, as a great volume of cold air is constantly being admitted at the discharge end of the cylinder. It will also be observed that the attrition on the shelves is a minimum, as there is not at any time a mass of material thereon.

In the rotary kilns the grinding action of the sliding mass of clinkers wears away the lining rapidly. This is obviated by the construction here shown, and, therefore, the cost of repairs is reduced to a minimum.

The required heat is generated by a suitable vapor burner or burners b.

It is of course necessary that the material be fed to the shelves in a uniform quantity. To-atta'in this hoppers M are-provided. These hoppers extend across the topof the series of chambers and are closed atthe'bot' tom by tworigid rectangular bars H and a central movable bar H, pivoted centrallyand actuatedby a lever K, having a fulcrum attached at the upper angle of bar H, Fig. 7,

the opposite edges of the square being in contact with theinner edgesnof bars H. When bar H is moved by the lever K an opening at n is left between the edges, and the powdered material is permitted to fall through the shelves. The lever is given motion at definite intervals, so that the material may be fed uniformly. The feed may be increased or diminished by lengthening or shortening the lever-fulcrum.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, isr 1. A kiln for the purpose described having one or more chambers, each chamber having a series of removable, adjustable shelves, 0

FREDERI'G M. L'XNDIQv \Vitnessesr WILLIAM ltIoLno-v,

I. H. MACDONALD.

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