US2031047A

US2031047A - Apparatus for manufacturing, treating, and cooling cement clinkers

Info

Publication number: US2031047A
Application number: US592774A
Authority: US
Inventors: Harry S Lee
Original assignee: Individual
Current assignee: Individual
Priority date: 1932-02-13
Filing date: 1932-02-13
Publication date: 1936-02-18
Anticipated expiration: 1953-02-18

Description

H. s. LEE 2,031,047-

NG CEMENT CLINKERS Feb. 18, 1936.

APPARATUS FOR MANUFACTURING, TREATING, AND COOL Filed Feb. 13, 1932 5 Sheets-Sheet l INVENTOR. Harry 3- L e B i IL I ATTORNEYS.

Feb. 18, 19336, H. 8. LEE 2,031,047

APPARATUS FOR MANUFACTURING, TREATING,. AND COOLING CEMENT CLINKERS Filed Feb. 13, 1932 5 Sheets-Sheet 2 ATTORNE Feb. 18, 1936. H. 5. LEE 2,031,047

APPARATUS FOR MANUFACTURING, TREATING, AND COOLING CEMENT GLINKERS INVENTOR. Harry S. Lee

ATTORNEYS.

H. 5. LEE 2,031,047

APPARATUS FOR MANUFACTURING, TREATING; AND COOLING CEMENT GLINKERS Feb. 18,1936.

.5 Sheets-Sheet 4 Filed Feb. 13, 1932 INVENTOR. Harry L, as

B? ATTORNEYS.

Feb. 18, 1936. 5, LEE 2,031,047

APPARATUS FOR MANUFACTURING, TREATING, AND COOLING CEMENT CLINKERS f/arig 5. Lee

ATTORNEY,$,

Patented Feb. 18, 1936 UNITED STATES PATENT OFFICE APPARATUS FOR MANUFACTURING, TREAT- ING, AND COOLING CEMENT CLINKERS 3 Claims.

My invention relates to improvements in the process and apparatus for manufacturing, treating, and cooling cement clinker.

An object is to provide an improved process 5 and apparatus whereby an improved clinker is produced at a reduced cost. A feature of my invention is the provision of such a process and apparatus whereby the kiln within which the clinker is formed is caused to function in a most efiicient manner and at a reduced cost and whereby the cooling of the clinker after it leaves the kiln is accomplished in a most efficient manner and a clinker of substantially improved quantity is produced.

In carrying out my improved process with the apparatus herein shown, I provide means for cooling the clinker very rapidly so as to produce clinker of an improved fineness and quantity. Of the air which is employed to cool the clinker, a selected portion which has been raised to a relatively high temperature is delivered into the kiln. This air is delivered into the kiln at a temperature substantially above the initial distillation or disintegration characteristic of the par- 7 ticular fuel used in the kiln, for example, be-

tween 900 and 1200 Fahr. This air is delivered at such a temperature and in such a quantity to the kiln as to measurably affect the heat inthe kiln and the combustion which occurs therein. In this manner I am able to appreciably control the functioning of the kiln.

An object is to appreciably control the functioning of the kiln through control exercised over this air and a subsidiary object is to control the characteristics of the air either manually or automatically.

A further object is to automatically control the temperature of the air by control automatically exercised over the bed of clinker being cooled and particularly by control automatically exercised over the movement and thickness of said clinker bed during the cooling operation.

The functioning of the kiln is further regulated by a control exercised over the feed of fuel into the kiln and particularly by a control exercised over the heated air employed to feed such fuel into the kiln. A subsidiary purpose is to heat such air, which fuel feed air is termed primary air, by heat withdrawn from the clinker during its cooling.

In carrying out this process an object is to take air which has been passed directly through the clinker in its cooling and through the clinker bed at its higher temperatures and to deliver the same in a predetermined quantity into the kiln, or rather into the enclosure or bustle which surrounds the fuel feed pipe that leads into the kiln to mix with the fuel before or as it enters the kiln and which assists to set up a substantial swirl and turbulence in said fuel stream, which has theretofore been mixed with a certain limited quantity of air at a lower temperature, so that aparticularly high combustion occurs immediately adjacent the entrance of the fuel into the kiln. A feature is that this swirling and turbulence at the entrance of the fuel and air into the kiln is in a direction opposite to the normal direction of rotation of the rotatable kiln. It is an object of my invention to deliver this highly heated air, which is termed secondary air, at a very high temperature so as to measurably control the temperature of the kiln.

Another object is to deliver the primary air which is used to feed the fuel into the kiln through the fuel feed apparatus at a temperature maintained below a predetermined maximum so as to prevent pre-ignition or destructive distillation of the fuel thereby. This primary air is delivered, however, at as high atemperature as is compatible with the characteristics of the fuel being used so that the kiln may be maintained in operation with the-minimum amount of fuel.

A further important feature is the employment in the process and apparatus illustrated of improved mechanism for cooling the clinker and employing the air so used for cooling in the functioning of the apparatus. One of the advantageous characteristics is that the clinker is moved through a stationary chamber in a bed or stream, the thickness of which may be varied at will or automatically in response to the requirements of the kiln as to heat. Means is provided to segregate selected portions of this air at varying temperatures for different uses. Means is provided to carry away the fine dust like particles'which fall from the bed or stream of clinker being conveyed and to deliver the same to a suitable depository. Means is provided to employ a sufficient quantity of air, not limited in any way by the demands of the kiln, to cool the clinker as rapidly as possible.

The cooling chamber employs refractory Walls at different portions throughout its length, which walls vary as to heat transference characteristics and as to heat and abrasive resistance characteristics. The cooling chamber is also fitted with dividing or levelling gate mechanisms, which are suitably cooled, and which are adapted to level off the bed of clinker as it is advanced and also adapted to divide the chamber into compartments for purposes of air distribution and kiln functioning as hereinafter described.

Various other objects and advantages of my invention will more fully appear from the following specification, appended claims, and accompanying drawings wherein:

Fig. 1 is an elevation of a structure embodying my invention shownalso partly in section,

Fig. 2 is a cross sectional .view taken online 2-2 of Fig. 1 and showing a portion of the cooling chamber in plan',

Fig. 3 is a cross sectional view taken on line 3-3 of Fig. 2,

Fig. 4 is a cross sectional view taken on line 4-8 .of Fig. 2,

Fig. 5 is a cross sectional view taken on line 55 of Fig. 1,

Fig. 6 is a cross sectional view taken on line 5-6 of Fig. 1,

Fig. '7 is a cross sectional view taken on line 'l'l of Fig. 1,

Fig. 8 is an enlarged cross sectional view taken on line 88 of Fig. 1,

Fig. 9 is an enlarged fragmentary sectional view taken on line'8-8 of Fig. 1, and

Fig. 10 is a view taken on line I 0--l0 of Fig. 1.

A general arrangement of the apparatus employed by me and utilized to carry out my process is shown in Fig. 1 wherein a rotary cement kiln of conventional type is indicated at 20. This kiln is adapted to discharge cement clinker from its lower end through a vertical passage way 22 as shown in Figs. 1 and 5. This clinker falls into a receptacle 24 in a cooling chamber indicated generally in Fig. 1 as 28. The receptacle 24 is arranged underneath a travelling drag chain 28 which passes through the chamber and is carried on sprockets 30 and 32. A driving belt is indicated as 34 which is adapted to drive at varying rates of speed, through variable speed drive mechanism 36, a belt 38 to actuate the drag chain 28 to move at varying rates of speed. The chain travels over a stationary grate 40. Cement clinker 42 is supported on the grate and actuated by the chain. The receptacle 24 is arranged underneath the forward end of the chain below the chute 22 so that the clinker falls therein.

The receptacle 24 and drag chain 28 are offset radially the axis of the rotating kiln as shown in Fig. 5. During the rotation of the'kiln the cement clinker rides up on the side toward which the kiln is rotating. By thisofisetting the clinker stream falls directly into the receptacle 24 and upon the moving drag chain. This is one feature of the construction.

The cooling chamber is jacketed as shown in the drawing and particularly as shown in Figs. 2,

5, 6, '7, 8, and 9. The inner wall of the cooling chamber is formed of suitable refractory material which will withstand the heat and abrasive action of the cement clinker at its highest temperature. The outer wall of the chamber is indicated as 44. The entire structure is supported upon suitable standards 48. The inner wall is indicated at the forward end as 48. By forward end is meant the end at which the-cement clinker is deposited into the chamber. The refractory wall at this end is of a very high test fire brick character which possesses high heat and abrasive resistance characteristics. The heat transference characteristic at this end is relatively low. The wall is made, of course, to withstand the heat of the clinker and the combustion which apparently occurs within this portion of the chamber,

The tail end of the chamber or the discharge end has an inner wall which is formed of a difierent character of material. A product known as Cementite indicated as may be used. It has a much higher heat transference characteristic than does the fire brick but its heat resistance capacity is less, though obviously suflicient for the purpose. This feature of a plurality of refractories of varying heat resistance and heat transference capacities is also a characteristic of the invention.

I provide a suitable blower 52 driven by a controlled variable speed electric motor 54 which communicates with a manifold 58. This manifold is provided with a series of feed pipes 58 which lead into the cooling chamber as shown particularly in Figs. 1, 2, 4, 5, 6, and 8. These are air passageways which discharge air from the manifold into the chamber below the grate 40 so that the air enters at spaced intervals throughout the length of the grate as appears in Fig. 1. The air moves up through the grate and about the cement clinker which is being advanced over the grate by the drag chain 28. There is a sloping wall 60 underneath the grate which leads to a trough or a passageway 62. This passageway extends lengthwise the chamber underneath the grate and at one side thereof and into which fine 'particles'of cement of a dust like character are discharged as they fall through the grate.

This trough 62 is provided with a conveyor 64 which is suitably driven as appears in Fig. 3 from a driving wheel. 66 which may be driven by a belt 68 from the same source as the drive for the drag chain 28. normally closed at its discharge end by a gate 10 held in the closed position by a counterweight 12. It is provided with a strip 14 which is adapted to be actuated by a swinging arm 16 which is in turn adapted to be actuated by a cam 18 mounted on the driving mechanism. This closure is therefore actuated at ,intervals to discharge the fine clinker particles which have been collected at such end of the trough. This trough discharges into a passageway 88 which leads to a suitable depository for such fine cement particles.

The travelling conveyor ,28 enters the chamber at the forward end through sealing mechanism indicated generally as 82, so that the chamber is kept sealed against the escape of fine clinker dust or the like. This construction is particularly described in an application filed of even date herewith by this inventor Serial No. 592,722. It is likewise sealed at other places as efiectively as possible, considering the use to which the mechanism is put.

The air which enters the chamber through the plurality of pipes 58 and which goes up through the grate and about the cement clinker being carried through the chamber is segregated so that a selected portion of the hottest air is taken into the kiln. It will be seen that the chamber is provided with a plurality of dividing gates or valve like levelling devices indicated generally by the number 84. Three of these are here shown. One of these devices is shown in detail in Fig. 8. An application of even date of this inventor- Serial No. 592,722 illustrates and describes specifically This trough or passageway is the construction of these levelling dividing gates.

For the purpose of this application it is to be noted that, as shown in Fig. 8, each of these gate structures is air cooled, is hollow and carried by a hollow shaft with which it communicates to receive cooling air therefrom.

In the construction shown in Fig. 8 there appears a hollow shaft 86 which communicates with the manifold 56 through the inlet pipe 88, illustrated in Fig. 2. This shaft carries a valve flap portion indicated generally in Fig. 8 as 90. This valve flap portion is shown as built up of three similar hollow sections. Each section communicates with the interior of the shaft to receive cooling air or other fluid therefrom. A shoe or wear plate member 92 is secured to the outer end of this flap portion and rests upon the cement clinker bed which is being advanced through the chamber. Each of these levelling dividing gates is held by a counterweight 94 to bear against the clinker to level the same. The counterweight is adjustable to bring the necessary pressure to bear on the bed of cement clinker.

These gates also serve another purpose. The first gate, or the one nearest the entrance of the cement clinker into the chamber, serves as a barrier to prevent air from flowing backwardly up through the clinker chute. The rear gate serves as a barrier to prevent escape of clinker dust and also entrance of air at such point. Obviously these seals are not absolute. In addition, at the rear end of the machine, is a gate 93 shown in Fig. 1.

The intermediate gate is adjustable within a slot 96 in the wall of the chamber. The shaft 86 of this intermediate gate is connected with the manifold 56 by a flexible conduit 98 to permit the adjustment of the gate lengthwise ofthe chamber. This adjustment is for the purpose of varying the relative size of the two compartments formed by this intermediate gate between the two end gates. This adjustment of the space of the compartments varies the amount of air taken off from each compartment and necessarily varies the temperature of the air. This is of particular importance with respect to the air taken off at the head of the chamber, which air is utilized in the kiln. The function of this is set forth in the description of the operation hereinafter.

As shown in Figs. 8 and 9, there is a seal provided about each one of these rotatable shafts at the inner wall where the opening for the shaft is oversize the shaft. The shaft 86 is shown as having a suitable bearing I in the outer wall. This bearing includes a rigid bracket I02 and a plate or casting I04 supported thereupon and of suflicient length to cover at any adjusted position the slot I06 formed in the outer wall The slot 96 formed in the inner wall is covered by plate IIII through which the shaft extends. This plate H0 is supported on bracket I I I. Spaced apart collars I I2 encircle the shaft and are held in spaced apart relationship by studs II 4 and expansion springs I I6 which urge the collars against the side walls and hold the plate I I0 against the inner wall 48 so as to prevent leakage of air or clinker dust at such point notwithstanding the adjustment of the device within the slot. The corresponding collars at the inner wall on the non-adjustable shafts also form a seal.

The air which passes through these shafts 86 and the hollow flap portions 90, as is more specifically described in the copending application above referred to, is later discharged from the opposite ends of such shafts. In the two forward shafts the discharge is into an exhaust manifold H8.

The cooling chamber is provided with a pair of air outlets one for each compartment formed by the intermediate gate structure. The outlet I leads from the forward compartment and the 1 air driven therethrough is carried by the pipe I22 insulated with refractory as at I23 to disencircles the fuel feed pipe I26. Fuel enters this feed pipe I26 through an intake I28 and is driven by what is termed the primary air, the system of which is later described, through such feed pipe I26 into the kiln. This feed pipe is of a suitable heat resisting alloy.

There is an outlet I30 from the rear compartment of the cooling chamber and from which air is taken by a pipe I32 to a suitable stack for exhaust.

In the functioning of the device it has been found that the temperature of the clinker is mo mentarily raised to a substantial extent in the forward compartment of the cooling chamber. This probably results from a residue of combustible material carried by the clinker into the cooling chamber from the kiln. The intermediate gate member is adjusted so that a desired quantity of air, as is dependent upon the necessities of the kiln, is taken off through the pipe I22. The temperature of this air is maintained at its highest possible factor of efliciency compatible with the functioning of the machine as, for example, 900 to 1200 Fahr.

The increase in temperature in the clinker in the cooling chamber occurs only during a relatively short time and then the temperature of the clinker rapidly falls. The fall in temperature is probably facilitated by the completion of the consumption of the residue of combustible material in the clinker and the intermediate gate is adjusted and located at a point where the air taken off through the pipe I 22 will have the desired high temperature. t

The air which is taken off through the conduit I32 is the air which is primarily responsible for the cooling. It has a substantially lower temperature than the air taken off through pipe I22. Such air may be put through the cooling chamber in any amount which is necessary to effect the desired rapidity of cooling of the clinker. As

its quantity does not effect in any way the functioning of the kiln it may be put through in whatever quantity is desired to perform the required cooling without any regard to the requirements of the kiln.

The space between the two walls of the chamber, shown particularly in Figs. 2, 5, 6, 7, and 8, is

the jacketed portion through which air is taken from the tail end of the cooling chamber as shown in Fig. 2. This airafter passing through such jacketed portion is driven bya control motor and the air passes from the blower into a portion of the fuel feed pipe I26 as shown in Fig. 1 and is used to drive the fuel into the kiln. The manifold II8 which collected the air from the hollow gate shafts 86 leads into this pipe I34.

This air should be taken off at as high a temperature as is possible but which will not induce preignition of the fuel and with the fuels conventionally used a temperature of 250 to 400 Fahr. has been found suitable. At such temperatures the air, which is mixed with the fuel, is at a temperature close to the point of distillation of the fuel but sufficiently below such point so that combustion will not occur prematurely. This air drives the fuel through the feed" v pipe I28.

This feed pipe is provided with deflectors I40 so that fuel and air enter the enclosure I24 in a turbulent swirling condition. This mixed fuel and air is picked up in the enclosure I24 by the large stream of air entering through tube I22.

This air, as heretofore stated, is very highly heated. Combustion occurs immediately and the fuel and air are swept into the kiln so that combustion takes place at the very entrance into the kiln. The enclosure I24,- which is also insulated as at I25, is provided with deflectors I42 which set up a swirl of these burning particles in a direction opposite to the directo'n of rotation of the kiln.

The feed pipe I26 is carried by a thimble I2'I mounted in a. plate I29 secured over the end of the enclosure as shown in Fig. 1. It is axially adjustable through such thimble by an adjustment indicated generally as I 3I which may be of a turn buckle character. The plate I29 is rotatably adjustable with respect to the enclosure I24. As the pipe and thimble mounting are eccentric with respect to the plate I29, rotatable adjustment of the plate adjusts the pipe with respect to the enclosure and kiln whereby the most efllcient position may be attained.

The temperature of the air entering through the tube I34 into the blower I33 is maintained by a thermostatically controlled device which admits atmospheric air as shown in Figs. 1 and 10. This includes a valve structure I44 which is operated from a reversible electric motor I46. Reversible movement of this motor is controlled by a switch I48. The switch is controlled by a thermostat I50 so positioned as to be responsive to the temperature of the air entering the blower so as to maintain a temperature at approximately a predetermined point. This point is below the preignition temperature" of the fuel as heretofore described.

To maintain the temperature of the air entering through the inlet I22 at the high temperature required to give the maximum emciency to the kiln there is provided a speed controlling mechanism in the form of. a conventional variable speed drive device 36, heretofore referred to, which regulates the travel of the drag chain 28. This variable speed mechanism is controlled by a reversible electric motor I52 which is in circuit as indicated at. I54 with a control switch I55. This switch is itself controlled by a thermostat I58 responsive to the temperature in the pipe I22. The reversing movements of this motor as they regulate the variable speed mechanism speed up or slow up the movement of the drag chain 28.

The variable speed device is provided with a master manual control, not specifically illustrated as the same is conventional apparatus, so that the movement of the drag chain may be manually regulated.

It is apparent that speeding up of the drag chain will cause the bedof cement clinker to thin out. Slowing 'up of the drag chain will cause the cement clinker to pile up and increase in thickness in the bed. In 'this manner the temperature of the air passing through the pipe I22 may be regulated. Through the thermostatic control this temperature may be maintained at substantially its maximum of emciency for facilitating the functioning of the kiln.

It is therefore possible to control the functioning of the kiln so that notwithstanding the noror portions of varying depth and combustion in a normal kiln is therefore interfered with. In

centage of air is admitted directly at a normally constant temperature.

It is likewise apparent that in this manner the quantity of fuel consumed is very materially reduced. In the functioning of a cement kiln it is necessary that there be maintained a definite proportion as to fuel and air to secure maximum emciency. An excess of fuel or air interferes with this balance or equilibrium. By the method I have shown and through the use of the apparatus disclosed it is possible to control, to a measurable degree, the temperature within the kiln. This control is secured by a control exercised over the secondary air passing through the pipe I22. The remaining air. which is needed for combustion, is taken in with the fuel feed, allowance being made as is always necessary for such leakage as will naturally occur, and the amount of which can be reasonably predetermined. w

What I claim:

1. In apparatus for the manufacture and treatment of cement clinker, a kiln having an outlet for the discharge of clinker, a fuel feed for the kiln, a stationary closed chamber to receive the clinker discharged from the kiln, clinker moving means arranged within said chamber to advance the clinker in a moving bed through the chamber, means for causing an air stream to pass through the chamber and through the moving clinker, means for delivering a. portion of said air from said chamber into the kiln, control mechanism responsive to the temperature of the air delivered from said chamber to the kiln coupled with the clinker moving mechanism to regulate the same as a function of said temperature.

2. Apparatus for the manufacture and treatmentof cement clinker comprising, in combination, a kiln, a cooling chamber communicating with the kiln to receive clinkers therefrom, clinker conveying mechanism operable to advance the clinker as a moving bed through the cooling chamber, driving means for the conveying mechanism, and means for causing a stream of air to pass through the moving bed of clinker to be heated thereby and for delivering said air heated by said clinker to the kiln, and control mechanism responsive to the temperature of the heated air delivered to the'kiln coupled with the clinker moving] mechanism to increase its rate of travel as the temperature of the heated air delivered to the kiln exceeds a determined temperature and to retard its rate of travel as the temperature of said air falls below a determined temperature.

3. Apparatus for the manufacture and treatment of cement clinker comprising. in combination, a kiln, a cooling chamber communicating with the kiln to receive clinker therefrom, clinker conveying mechanism operable to advance the 2 clinker as a moving bed through the cooling chamber, means for causing a stream of air to passthrough the clinker in the forward portion of said bed to be heated thereby and delivering said air so heated into the kiln, means for causing a stream of air to pass through the clinker in the remaining-portion of said bed to cool the clinker, means for controlling the temperature of the air delivered from the forward portion of the bed to the kiln, and mechanism responsive to the temperature of said air and coupled with the clinker conveying mechanism toregulate the speed thereof as a function of the temperature of said air.

HARRY S. LEE.