US1844782A - Apparatus for cooling loose material - Google Patents

Description

3 Sheets-Sheet l Feb. 9, 1932. c. MITTAG APPARATUS FOR COOLING LOOSE MATERIAL Filed Oct. 30, 1926 /f 1/ /f f f///// l Feb. 9, 1932. c. MITTAG 1,844,782

APPARATUS FOR COOLING LOOSE MATERIAL Filed oct. 30, 192e 5 sheets-sheet 2 ation/441,11

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Feb. 9, 1932. c. MITTAG 1,844,782

APPARATUS FOR COOLING LOOSE MATERIAL Filed oct. so, 1926 s sheets-sheet s .Patented Feb. 9, 19324v UNITED STATES PATENT. 'oFFlcE ,l CARL MITTAG,.OF MAGDEBURG, GERMANY, ASSIGNOR TO FRIED-EBU?? GBUSONWEBK,

A. G., F MAGDEBURG-BUCKAU, GERMANY APPARATUS FOB. COOLING LOOSE MATERIAL Application filed October 80, 1926. Serial No. 145,359.

This invention relates to devices for cooling loose material such as clinker from a cement kiln.

The clinker comes out of the kiln at a temperature of about 1000 C. and at the present time is usually carried oif and allowed to cooll without any. special provision for hastening the cooling. One object of the present invention is to provide an arrangement whereby the clinker can be cooled down as quickly as possible after leaving the kiln.

Another object of the invention is to move the clinker slowly forward in a thin layer in the opposite direction to a stream of cooling air, the moving means being so constructed as to constantly turn the clinker over and over as it is moved forward, whereby all parts of the clinker will'be brought into contact with the cooling medium.

Another object is to pass the clinker to be cooled over a platform constructed of material having high heat conductivity, and to pass streams of air over and under the platform, the upper stream taking the heat by direct contact with the clinker, wnlle the lower stream takes up heat transmitted through the platform.

If it is found desirable to increase the coolling effect by spraying water over the clinker this will be done at a point where the clinker has been cooled to a certain extent. The upper stream of air then not .only dries the clinker but also carries off. the evaporated water. In this case the combustion air is taken only from the lower stream of air.

Other objects and advantages will appear from the following specification and accompanying drawings in which certain embodiments of the invention are described and ilvlustrated by way of example. In the drawings Fig. 1 is a vertical longitudinal section of one form of the device,

Fig. 2 is a cross section on the line 2 2 of Fig. 1f,

Fig. 3 is a longitudinal section of another form of the invention,

Fig. 4 is a longitudinal section of still another form of the invention,

Fig. 5 is a plan view of a portion of the chain conveyor shown in Figs. 1, 2, and 3, and

Fig. 6 is a plan view of a portion of another form of conveyor which may be used in either the device shown in Figs. 1 and 2, or that of Fig. 3.

The arrangement according to Figs. 1 and 2 will be described first. Over the discharge end of the rotary kiln 1 is arranged a hood 2 the connection between the two being constructecl so as to exclude air as far as possible. The bottom of the hood opens into a hole 3 in the top 4 of a housing 4. Partitions 5 and 6 extend downwardly from the top 4 on opposite sides of the hole 3 and form, to ether with the side walls 7 and 8 of the housmg 4', a shaft 5. At a short distance below the lower ends of partitions 5 and 6 is arranged a platform 9. These parts are all made of re brick to withstand the high temperature of the clinker. Y

Beyond the end of platform 9 extends a metallic shelf 10. A conveyor 11 is mounted on sprockets 12 and 13 so that its upper flight extends along the top of platform 9, 10 and its lower flight passes under the same. The

sprocket 12 is connected by means of suitable gearing 14 to a variable speed motor 14 which moves the conveyor in the direction indicated by the arrow m. The clinker falls from the kiln 1 through hood 2 and shaft 5 and piles up on the platform 9. The upper flight of the conveyor passes through the bottom of the pile of clinker and spreads the same out into a thin layer on the surface of the shelf 10.

The speed of the conveyor isso regulated that there is always a sufficient pile of clinker extending into the shaft 5 to seal the space between platform 9 and the lower ends of partitions 5 and 6.

On the top 4 is arranged a blower 15', the suction conduit 16 of which passes through the top, and the exhaust conduit 17 of which opens into the atmosphere. A partition 18 is arranged a short distance above the shelf 10 formin a passage 19, and a wall 20 seals the end of space 21. The air drawn in by the blower 15 must therefore pass along the passage 19 in close contact with the clinker and then back through space 21 to the blower.

A second blower 22, also mounted on top 4, has an exhaust conduit 23 opening into the hood 2 and a suction conduit 24 opening into a chamber 25 communicating with the passage 26 below platform 9, 10. The blower 22 supplies air for combustion, which has been preheated by contact with platform 9, 10, to the kiln 1, and also serves to blow fuel, such as coal dust, which is fed from hopper 27, into the kiln.

The cross bars 28 of the conveyor 11 are constructed as shown in detail in Fig. 5, their upper surfaces being in the form of a series of plow shares. As these shares are drawn through the layer of clinker they con stantly turn it over and over as they move it slowly forward, so that all the particles of clinker are brought in contact with the cooling air in passage 19 andalso with the shelf 10 cooled by the air passing through space 26. A bar having right hand plow shares is followed by one having left hand plow shares so that the material is kept evenly distributed over the surface of the shelf. The cooling of shelf 10 can be made more rapid by providing its lower surface with ribs 28.

`vTo speed the cooling still more a rose 29 may be provided for sprinkling the clinker. The water evaporates and is carried oil" by the air passing over the clinker. This water does not get into the combustion air which is drawn only from the lower passage 26. Flap valves 29', 30 are provided for regulating the flow of air through each blower. The clinker drops from the end of shelf 10 into a conveyor 37 of any suitable form. A sight hole is provided at 39 for observing the height of the pile of clinker which can be regulated by changing the variable speed motor 14. This is necessary because the amount of discharge from the kiln is not constant.

If water is not to be used for cooling, the arrangement `shown in Fig. 3 ma be used. This apparatus is exactly like the first described except in the details which will now be pointed out. The single blower 31 has a suction conduit extending through top 4. Its exhaust conduit is branched, one branch, 32 leading to the hood 2 and the other, 33 opening into the atmosphere. The flap valves 34 and 34 are provided for regulating the quantity of air passing into the kiln. The space 25 is connected to the space 21 by means of a by-pass 35 in which is arranged a flap valve 36 for regulating the proportion of air passing through passages 19 and 26. A valve 37 may also be provided for regulating the total flow of air through the blower. With this arrangement one blower is eliminated without sacrificing any facility of regulation.

In Fig. 6 another form of conveyor is shown which Consists of a plurality of chains 38 each of which bears a series of plow shares 39. In this form also a transverse series of right hand plow shares is followed by a transverse series of left hand low shares. The exact form of the system o plows used is not important,lthe essence of this part of my invention being a device which will turn the material over and over as it moves it forward so as to bring all the particles of clinker in contact with the cooling media.

A particularly desirable form of the invention, especially for small kilns, is shown in Fig. 4. In this case again the kiln 1 discharges into the hood 2 'which communicates at the bottom with a hole 3 in top 4. The clinker is discharged into the pit 40 formed by walls 41. The bottom of the pit is a platform 42 of fire brick which forms the central portion of a rotary circular table. A ring shaped flange of metal, 44 completes the surface of the table. The lower surface of the metal ring is provided ,with a plurality of radiating ribs 45 which rest on a second ring 46 provided at its center with a hollow hub 47. The hub is rotatably mounted in a suitable hollow casting 48, the hub 47 and casting 48 having flanges 47 and 48 respectively, between which are interposed ball bearings 62. The table is rotated by means of gears 49, 50, 51 and 52 driven by a suitable source of power. Air is sucked in through the space between rings 44 and 46 into the hollow hub 47 and casting 48, thence through conduit 53, by blower 54. The exhaust conduit of blower 54 opens into hood 2. A second blower 57 draws air over the clinker through a space formed between a stationary upper plate 55 and the surface of the table, thence through conduit 56, and discharges it into the atmosphere. The plate 46 and hub 47 and the plate 55 correspond in this embodiment to the housing 4 of the first two forms shown, the space between .these parts being divided by the ring 44 and platform 42 into two compartments. A series of stationary plows 58 are arranged on radiating beams 59. The plows turn the material over and over as they move it outward from the center of the table. A water sprinkler 61 can also be used with this form of apparatus. The material is discharged from the periphery of the table by means of a stationary scoop 60.

Having described my invention, I claim:

1. Apparatus for cooling pulverulent or granular material comprising a platform, an endless chain arranged soy that one span of the same passes over said platform, a system of plows on said endless chain, means for dumping the material onto said platform, means for moving said endless chain to cause said plows to spread the material in a thin layer on said platform, to advance the material along the platform, and to plow the material over and over as it advances, and means for passing a cooling medium in heat exchanging relation with the thin layer of material.

2. Apparatus for cooling pulverulent or granular material comprising a platform composed of material having a high coeiiicient of thermal conductivity, means for spreading and advancing the pulverulent or granular material in a thin layer along said platform, and means for passing two separate streams of a cooling medium above and below said platform respectively, both in countercurrent with respect to the travel of the material.

3. The combination with a cement kiln of a cooling apparatus for the clinker discharged therefrom comprising a housing divided into two compartments, at least a portion of the dividing partition thereof being in the form of a platform composed of material having a high coefficient of thermal conductivity, means for spreading and advancing the clinker in a thin layer along said platform, means for sprinkling water upon said thin layer of clinker, means for passing two separate streams of cooling air through said compartments, both incounter current with respect to the travel of the material, and means for conveying air from the compartment at the opposite side of the partition to said layer to the kiln for combustion purposes.

4. Apparatus for cooling pulverulent or granular material comprising a housing, a platform within said housing, at least a portion of said platform being'composed of material having a high coefficient of thermal conductivity, a shaft formed by walls extending from the top of said housing to within a short distance of said platform, said shaft being adapted to receive and convey the loose material to said platform, the arrangement being such that the space within said housing is divided into two separate 'compartments by said platform, said shaft, and the material piled upon said platform below said shaft, an endless chain arranged so that one span runs over said platform and through said pile of material while the other span returns under said platform, means on said chain to carry the loose material forward and spread it in a thin layer upon said platform, and means for causing two separate streams of cooling medium to pass through said two chambers in counter current to the loose material.

5. In an apparatus for cooling pulverulent or granular material discharged from a kiln, a platform comprising a section composed of a refractory substance positioned to receive directly the material discharged from the kiln and a section composed of a substance having a high coefficient of thermal conductivity, means to move the material from the receiving section and over the other section in a thin layer, and means to cause two separate streams of cooling air to pass above and below the platform in counter current to the travel of the material.

6. In an apparatus for cooling pulverulent or granular material, a shaft, a substantially horizontal platform beneath the shaft, said shaft and a portion of the platform being adapted to receive the material as it is discharged from a kiln, means for withdrawing the material from said platform portion and passing it in a thin layer over another portion of the platform, said other portion being composed of a substance having high thermal conductivity and means for forcing air in separate and distinct currents above and below the platform in counter current to the travel of the material.

7. The combination with a kiln adapted to produce hot pulverulent or granular material, of apparatus for cooling said material comprising a shaft, a substantially horizontal platform beneath the shaft, said shaft and a portion of the platform being adapted to receive the material as it is discharged from the kiln, means for passing the material in a thin layer over another portion of the platform, said other portion being composed of a substance having a high thermal conductivity means for forcing air in separate and distinct currents above and below the platform in counter current to the travel of the material, a sprinkler arranged to discharge above the platform and a conduit for conducting the air emerging from the lower side of the platform to the kiln for combustion purposes.

8. Apparatus for cooling pulverulent or granular material, comprising a rotary table havingsacentral section composed of refractory material adapted to receive the hot material, and a surround section composed o f a substance having high thermal conductivity, plates above and below said table .in spaced relation forming two air conduits upon opposite sides of said table, sa1dyconduits being open at the edge of the table, means for drawing two separate currents of air through said conduits toward the center of the table, and stationary shovels arranged above said table and adapted to dig the material away from said central sectlon as the table rotates and to advance the material in a thin layer toward the edge of the table.

9. Apparatus as described in claim 8 1n which said rotary table is mounted upon a .hollow hub communicating with the air conduit under said table and `in which a suction fication is signed.

CARL MITTAG.

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