US1463363A - Cement-kiln system - Google Patents

Description

July 3l`, 1923.

D. S. JACOBUS CEMENT Kme sYs'rsu Filed Aug. 17. 1916 15 Sheets-Sheet 1 1mm/ron @Liq :all Il July-31, 1923. 1,463,363

D. S. JACOBUS GEMENTKIVLN SYSTEM Filed Aux. 17. 1916 15 Sheets-Sheet 2 CEMENT KILN SYSTEM Filed Ault. 17. 1916 15 Sheets-Sheet 5 /AJ ATTORNEYS.

July 31, 19243.V 1,463,363

- D. s. JAcoBus CEMENT KILN SYSTEM I IlIl July 31,1923.

D. s. JAcoEus CEMENT KILN SYSTEM Filed All2- 17. 1-916 15 Sheets-Sheet 5 INTOR. 52%

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July 3l, l923.

D. s. JACOBUS CEMENT Kme s'sTu Fi1ed Au1. 17. 1916 15 Sheets-Sheet 6 NV roR.

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Jury a1, 1923.

n. s. JAccBus CEMENT KILH SYSTEI 15 Sheets-Sheet 8 Filed Lul. 17. 1916 ...........fll.......mw'

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July 31,1923.

D. S. JACOB US CEMENT KILN SYSTEM 15 sheets-sheet Filed Anl. 17. 1916 July 31, 1923.

D. S. JACOBUS CEMENT KILN SYSTEM Filed Anz. 17. 1916 15 Sheets-Sheet l 0 IN VEN TOR.

/A'ATroRNEYs.

July 3l, 1923. 1,463,363

D. s. JAcoBus CEMENT K I LN SYSTEM Filed Aug. 137-. 1916 15 Shasta-Sheet 11 /AJATTORNEYs July 3l, 1923.

, D. s. JAcoBus ummm MLN SYSTEM Filed Aug. 17. 1916 15 Sheets-Sheet 12 INVEN TOR.

/uI A TTORNEYS.

July 31, 1923.

D. ,5. JACOBUS CEMENT KILN SYSTEM 15 Sheets-Sheet 13 Filet@ Ault. 17. 1 916 July 31, 1923.

D. s. JAcoBus CEMENT KILN SYSTEM 15 Sheets-Shee 14 Filed Auk. 1'7. 1916 JNVENTOR.

/JA TTORNEYS.

D. S. JACOBUS CEMENT KILN SYSTEM Juy 3f, T923.

Filed M11 17, 1916 15 Sheets-Sheet 15 Patented July 31, 1923.

UNITED STATES 1,463,363 PATENT OFFICE.

DAVID S. JACOBUB, F JERSEY CITY, NEW JERSEY, .ABSIGNUR T0 THE BABCOCK WILCQX COMPANY, 0F BAYONNE, NEW JERSEY, A CORPORATION 0F NEW JERSEY.

CEMENT-mn sYsTEx.

Application lled August 17, 1918. Serial No. 115,507.

To all whom. it may.' concern:

Be it known that I, Davm S. JAoosUs, a citizen of the United States, residing at Jersey Cit in the county of Hudson and State of cw Jersey, have invented certain new and useful Improvements in Cement- Kiln Systems, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1 is a plan view, artly in section, showmg a portion of a ust-settling flue and wasteheat boiler setting for cement kilns;

Fig. 2 is a sectional side elevation of Fig. 1, showin the waste heat boiler and connections in p ace;

Fig. 3 is a cross section on the line III- III of the iiue part of Fig. 2;

Fig. 4 is a detail .vertical sectlon of the connection between the kiln stack and the common flue on the plane of the line IV-IV of Fig. 1;

F ig. 5 is a sectional side elevation showing the boiler and dust recovery system which I ma em loy with any of the forms of dust-setting ues shown;

Fig. 6 is a partial top lan view of the dry dust catcher system o Fig. 5;

Fig. 7 is a longitudinal section showing a modified form of dust separator;

Fig. 8 is a longitudinal vertical section of a dry dust catcher and series washer and economizer which I may employ with any of the boilers shown;

Fig. 9 is a sectional side elevation of the economizer of Fig. 8 showing the pipe arran ment;

ig. 10 is a detail view of one of the spray pines for the economizer of Figs.r8 and 9;

Fig. 11 is a longitudinal section showing a modified form of series washer;

Fig. 12 is a vertical section, taken along the line XII- XII of Fig. 11;

Fig. 13 is a detail view of one of the shakers. taken along the line XIII-XIII of Fig. 14;

Fig. 14 is a plan view of the shaker taken partially along the line XIV- XIV Fig. 13;

Fig. 15 is an elevation of a modified form of shaker;

Fig. 16 is a plan view of the modified form of shaker of Fig. 15;

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Fig. 17 is a detail view, partially in section, of a part of the modified form of shakerof Figs. 15 and 16;

Fi 18 is a diagrammatic cross section showing the caking action of hot cement dust on stationary rods;

Fig. 19 is a similar view showing the caking action of hot cement dust on rotating 'rods' Fi 20 is a front elevation of a screen of rotating rods;

Fig. 21 is an enlarged partial front elevation of the screen of Fi 20;

F Fig. 22 is a side View o one of the rods of i 23 is a sectional elevation of a modified orm of Hue system;

Fig. 24 is a cross section of Fig. 23, on line XXIV-XXIV.

Fig. 25 is an elevation of one of the rod screens emplo ed for the form of Fig. 23;

A Fig. 26 is a horizontal section on the irregular line XXVI-XXVI of Fig. 23;

Fig. 27 is a horizontal section showing a modified arrangement of rotating screens;

Fig. 28 is a diagrammatic lan view show ing another form of rod-ho ding and turning system;

Fig. 29 is an enlarged plan detail of one of the rotating elements of Fig. 28;

Fig. 30 is a sectional side elevation showing another form of dust-collecting line and boiler system with a washer;

Fig. 31 is aplan view partly in section of Fig. 30;

Fig. 32 is a detail view of one of the screens of Fig. 30;

Fig. 33 is a cross. sectional view of the form of Figs. 30 and 31, taken on line XXXIII-XXXIII of Fig. 31, looking to ward the boiler;

Fig. 34 is a detail view of a double washer system which may be used instead of the single washer system;

Fig. 34 is a detail view of a modification of Fig. 8;

Fig. 35 is a sectional side elevation showing a modified form of washers for the gases from a waste heat'boiler;

Fig. 36 is a top plan view, partly broken away, of the washers of Fig. 35 showing the valve arrangement for switching from one washer to the other; l

Fig. 37 is a detail view showing the com nections for operating the rotating shelf pieces of Fig. 35;

Fig. 38 is a detail view of one of the driving connections for giving orbital motion to a driving plate for rotating the shelf pieces of Fig. 35;

Fig. 39 is a sectional side elevation artly on the broken une XXXIX-xxiifx of Fi 40, showing a modified form of multip e washer system; and

Fig. 40 is a vertical section on the line XL-XL of Fig. 39.

My invention relates to the handlin of dust from cement kilns. The object o the invention is to provide a method and apparatus for removing and recovering the dust which, in addition to saving the dust which is a valuable part of the material fed to the kilns, will avoid the nuisance of the settlement of dust on the surroundin grounds and buildings. It is also designe to provide for recovery of valuable products from the gases, as I have found that by suitably treating the dust-laden gases, certain valuable ortions may be separated out and recovered) separately from the dust pro er.

T e invention also relates to the reduction of the temperature of the gases, preferably by a waste heat absorbing device, prior to the final separation of the dust therefrom. The invention also relates to certain combinations and arrangements of parts here inafter described, the advantages of which will be ap arent to those skilled in the art from the ollowing description:

Referring to the drawings, Figs. 1, 2 3 and 4 show a form of cement kiln and flue connections which may be used with the boiler arrangement shown, or with other boiler arrangements such as those shown in the other figures; it will be understood that any of the boilers and dust recover systems for such boilers may be used with any of the Hue systems shown herein. i

In Figs. 1, 2, 3 and 4 the numerals 2, 2, represent two of a series of inclined rotary cement kilns havin water-cooled spouts 3 (Fig. 3 through w ich the cement material is fed or clinkering or sintering. The upper end of each kiln into which the cementforming material is fed, dischar es the waste gas into the base portion 4 o an individual stack 5, this base portion having side doors 6, through which this base portion of the stack may be reached for clean .lver the higher ends of the rotary cement kilns extends a common-dust settling ilue 7, having hoppers 8 between the kilns. One

side of this ilus is connected with the cement kiln stacks through openings 9, as shown in detail in Fi Y. 3 and 4. These openings may be contro led by suitable closure plates or damper-s (not shown) movable in slots 11 (Fig. 4). When the kilns are discharging into the flue 7, the dampers in these slots are entirely removed and the slots covered by bricks or tiles t; and to regulate the flow of ases from the kilns to the flue and equalize the flow between the various kilns, bricks or tiles ma be laid in, as shown at l2. A door 13 Fig. 4) may be provided for introducing these bricks or tiles.

Experiments with these systems have shown that with certain grades of raw material some of the dust from the kilns will collect in caked form on hot surfaces, and

that this caked material contains potash 80 salts and other ingredients which make it valuable. It is therefore important to collect as much as possible of this caking material, as it ma be sold at a much higher price than the nished cement.

In the apparatus shown in Figs. 1, Q, 3 and 4, inwardly projecting wing walls 14 are provided which cause eddies to form in the dust carrying aseous current, which assists both in the the hoppers and in the deposition of the caking material on the sides of the flue. The sides of the llue and the wing walls become heated by the gases, and the caking material adheres to such hot surfaces. Instead of the hot surfaces above described for the collection of the caking material, other forms of hot surfaces may be employed, such as the rods or screen systems shown in other fi ures of the drawings and hereinafter descri ed.

The part of the dust adhering or cakin to the hot surfaces has a different chemica composition from the rest of the dust which will not so adhere. It is therefore possible by means of the apparatus herein described to effect a separation of the dust having the caking characteristics from the remainder of the dust, thus recovering a valuable byproduct from the cement kiln dust.

In the form of Figs. 1, 2, 3 and 4, the caking material which collects on the walls of the Hue is not rmly fused to the brickwork, and but little force is required to dislodge it. To remove this collection of caked material, I may employ a cleaning device 15, attached to a chain 16, which may be lowered through any of the doors 17 in the top of the flue, these doors being adjacent to the side walls to give easy access thereto. The chain may pass over a hand windlass 1.8, on the top of the flue, by which the chain may be raised and lowered. In order to reach more of the wall surface, the chain may be swun from side to side by means of a bar 19, with a ring or prong at its lower end, as shown at 20, which engages the chain, this bar projecting throu h one of the holes in the topA of the flue. ith a device of this character, the sides of the due may eposition of dust in be reached, except some portions near the top of the side walls, and these upper portions, as well as the roof of the flue, may be reached by curved bars passing through the doors 17. I may also use a wndlass or windlassess 18", as shown in Fig. 2, having two chains 16, extending through two of the adjoining doors in the top of the flue and connected to a horizontal scraper bar 15, extending between and beyond the chains. These cleaning means may be used while the hot gases are passing through the flue, so that the kilns need not be shut down for such cleaning. y

In order to clean the openings 9, between the furnace stacks and the ue, the stacks may be provided with doors 21, opposite the openings 9, and through which bars may be passed for cleaning oil` any deposit in the openings.' A cleaning device may also be dropped through this opening for cleaning olf the lower part of the stack.

In order to segregate the valuable caking material from the dust collecting in the hoppers, I preferably first remove all the loose dust from the ho per beneath the portion of the wall to be c eaned, and then break up and remove the caked material, so that it will collect in the spouts S below the hopper from which it may then be removed.

From the flue 7, the hot gases pass through a heat-absorbing device, which reduces their temperature before passing to the apparatus beyond, in which the final separation of the dust is effected. The heat-absorbing device is preferably one in which the waste heat is utilized, and is illustrated in the drawings as `a waste heat boiler 22, connected at the end of the ilue, this boiler being of the general Babcock & Wilcox type with three vertical passes, beneath which are located dust ho pers 8", to collect the dust dropping from the gases passing through the boiler. The hoppers both for the flue and boiler are also preferably provided with side doors 24, through which cleaning devices may be inserted for cleaning the hoppers when needed.

The waste heat boiler 22 eil'ects a considerable reduction in the temperature of the gases, and therefore their volume, thereby reducing the velocity of the gases and permitting the dust to be more readily separated therefrom, not. only during the paage of the gases through the passes of the boiler, but also in the dust separator system through which the gases are afterward passed to effeet the final separation of the dust. Because of the cooling of the gases, the dry dust separators beyond the boiler have gases of less volume and consequently of less velocity to handle.' Moreover, the washers through which the gases subsequentl pass operate much more satisfactorily on t e cooled gases as very hot gases tend to evaporate an carry away the s ray water in the form of steam and inter ere with the satisfactory operation of the washers generally. Also, the cooled gases are much more readily handled by the fan. In cases where the inal removal of the dust is effected by electrical means, the reduction in temperature of the gases is of great advantage.

'1` he non-caking dust collected in the hoppers 8* beneath the boiler from the gases as they are cooled in their passage through the boiler passes, is of a diiferent nature from the non-caking dust collected in the flue 7, and in some instances contains enough potash to warrant its recovery from the dust. The introduction of the boiler influences the character and amount of dust collected at this point.

In Figs'. 5 and 6, -I show one form of a separator system for the gases coming from the Waste heat boiler, fed from a cement kiln flue. In these figures, 25 represents a Babcock & Wilcox boiler of the cross drum type, the waste gases from the cement ilue entering through the flue 2G and passing out through the flue 27, to the economizer 28, and thence through Hue 29 to fan 30. Some water from the boiler may be used for the economizer where the feed water supply is not hot enough to prevent sweating of the economizer pipes, since the dust will stick to a sweating pipe. Such water drawn from the boiler passes through a settling chamber 25', and is forced by a centrifugal pump 32 through a valved pipe 33 into pipe 34 leading to the economizer 28. A feed water heater 35 is shown for heating the feed water, before it enters the feed pump 36, by which it is forced through pipes 37 and 34 into the economizer. Steam for this feed water heater 35 may be takenv from the steam turbine 38, which is emplo ed for operating the induced draft fan 30, tliis steam passing down to the heater 35 through pipe 39.

From the induced draft fan, the gases are led tangentially into the dry dust catchers or -separators 4:0, of which I show two in series. Wardly directed entering gaseous current, together with the change in direction, owing to the outlets 41 being at the top.` will cause the dust to settle in the hopper bottoms of these separators. The quality of the du'st in the separators will vary, that which is farthest from the kilns containing the greater amount of potash. In certain instances the potash may be recovered from the dust from some of the separators and not from others. In any case the dust which is recovered is suitable for returning to the kilns by mixing it with the raw material fed to the kilns, and in rcalit formsthe best part of the product fed to t e kilns as it is in the mose finely divided state.

Instead of the dry separators of Figs. 5

The centrifugal force of the down` lll and 6, I may employ the separating system of Fig. 7, in which the gases entering from the boiler through flue 42 enter aI large gravity separaborl. This separating chamber has partitions or baflles 44 and 45, which cause the gases to flow slowly up and down in an upward and downward course through the chamber. In this type of separator the reduction in volume and velocity of the gases due to their cooling in the waste heat boiler is of especial importance. The heavier particles of dust collect in the lower hoppers 46, and may be removed by conveyors 46'. The gases flow into the up er portion of a washer 47, which may be similar to the washers hereinafter more fully shown and described and which remove the finer particles of dust and certain gaseous matter.

In Figs. 8 and 9, I show a combined dry separator 48, a Washing system 49 and a feed water heater or economizer 50, for the gases coming from the Waste heat boiler. In this case, the dry separator 48 may be similar to one of the separators of Figs. 5 and 6, the flue 5l from its to entering the top of one member of the waslling system. The Washer consists of a large chamber divided by partitions 52 into a series of chambers communicating with each other alternately at the top and bottom so that the gases flow in an upward and downward course therethrough. In the last pass of this flow, the

ases are acted upon by a fresh water spray rom spray pipe 54, which rojects into the upper part of the right han compartment of the last chamber. The water collecting in the lower part of this last chamber is drawn out through pipe 55 to a circulating pump 56, which lifts it to the spray pipes 57 and 57".

The pump 56 and spray pipes 57 recirculate the Water through the last chamber while the spray pipe 57" sprays a portion of the water into the middle chamber, the amount being regulated by means of a valve 57. The water dropping in the middle chamber passes out throu h the pipe 55 to circulating pump 56, whic lifts it through pipe 56" to the spray pipes 57b and 57, both spraying in the central chamber; the pipe 56" also leads water to the pi es 57, which spray water in the right han com artment of the first chamber. the amount ing regulated by means of a valve 56. The spray pipes 57c spray water over the feed Water heater, shown at 50. From the first chamber the water descends through pipe 55" to pump 56" which lifts it to the spray pipes 57, which spray water in both compartments of the first chamber. In this way the water is recirculated throu h both compartments of each chamber endg a portion of the water from each chamber except the first passes back to the chamber in advance of it, so that the concentration of the `water in each of the chambers becomes successively greater from the last toward the first chamber. The concentrated water may be drawn off from th lirst chamber through the tap or valve 13 In one of the left-hand compartments of the center chamber I locate the feed water heater or economizer 50, shown in detail in Fig. 9, and comprising alternate opposite headers 58, connected by inclined horizontal pipes 59 (Fi 9). The circulating pump 56 is preferaEly larger than the others, and lifts the water to the series of special spray pipes 57, which spray the water over the feed water heater tubes, thus giving a greater flow of Water to prevent the material building up on the tubes of the feed water heater.

The'dust from the cement kilns will bccome attached to tubes or pipes where there is a limited amount of moisture or water, but by providing excess of water, the tendency of the dust to attach to the tubes is greatly lessened. The feed water heater or economizer is so built that the tubes are readily accessible. The feed water preferably enters at the bottom and is taken out at the top. This feed water may'be used in connection with the Waste heat boiler of any of the figures.

In the bottom hopper of each double chamber of thewasher I employ scraping blades 61 on hubs 61, each journaled in the bottom of a hopper and carrying, exterior thereof, a worm wheel meshing with a Worm on shaft 62a driven by any suitable connections. A Wall of each hopper is extended and downwardly inclined to form the bottom wall 49e of the open top trough-like structure E, so that the mud passing from the hopper and lodging in the trough, may be removed by a grab bucket 49, 0r by other means, such as a screw or drag conveyor. In Fig. 8 the normal position of structure E is shown in full lines for the first and middle chambers, and in dotted lines for the last chamber. The structure shown in full lines for the last chamber is designedly turned out of position for purposes of illustration. The concentrated solution may be drawn from the bottom of the first chamber by means of a tap or valve 137.

In Figs. 11 to 14 is illustrated another form of washing system for the gases coming from the waste heat boiler, the feed water heater or economizer being omitted. In the form shown the fresh water is fed through pipe 150 to spray 151 in the righthand compartment of the last chamber. In this wa the coldest water is sprayed into the col est gases, and the fresh water is sprayed into the cleanest gases, as in Fig. 8.

In addition to the water sprayed through pipe 150, I also introduce Water into the right-hand compartment, of the last chamber from tank 66, through pump 152, pipe 153 `and spray 154. The water from the bottom of the last chamber passes downward through pipe 155 to pump 156, and is raised by the latter to sprays 157 in both compartments of the last chamber and also to spray 158 in the right-hand compartment of the third chamber. The amount of water passing through spray 158 is regulated by a valve 159, through means exterior of the casing. The water is recirculated through the other compartments and chambers in the same general way by the pipes, pumps and sprays shown in the drawing. The concentrated water is drawn oil' from the first chamber through the tap or valve 138.

In connection with this washing system is shown a system for collecting the dust washed from the gases. In this system the scraper blades 61b are connected to chains 62, which are run continuously in the same direction. The material in the form of mud is removed from the bottoms of the spray chambers by means of conveyors 64", shown in Fig. 12. The tube 139, in which the conveyor runs, extends exteriorly to a level above the water line in the spray chambers, so that the water is not taken from the spray chambers by the action of the conveyor. The conveyors are run by sprocket wheels 63 in the direction indicated by the arrows. The material taken by the conveyors 64 is delivered to the tank 66. The conveyor blades as they ass above the tank are washed by means o a spray supplied from a water pi 68, the water and washed off material .fa ing into the tank 66. The material collecting in the bottom tank is carried along its inclined bottom by the chain and scraper system 70, and is delivered to a second conveyor 71. The conveyor 71, like the conveyor 64", consists of a chain carrying a number of conveyor blades and driven in thedirection indicated by the arrows b sprockets71. The conveyor 71 delivers t e material taken from the bottom of the tank 66 onto a belt conveyor 72, travcling on an inclined pulley system over a tank 73. Shakers or strikers 139'l are arranged to dislodge the material from the conve or 71 and cause it to fall on the belt 72. ne of the strikers 139* is shown in detail in Figs. 13 and 14, and consists of a tapper arm 140 actuated by means of a spring 141 and cam wheel 142 to strikeA the blades of the conveyor and knock of the wet materialadhering to them. y t In Figs. 15, 16 and 17 is illustrated a modified form of knocker for clearing the conveyor blades of the wet material. This form of knocker consists of a number of rods 143 hung by means of chains 144 from a circular plate 145. The plate is raised and suddenly allowed to drop b means of a cam wheel 146 vengaleging a rol er 147 carred by the plate supporting shaft 148. The rods 143 fall against the conveyor blades and chain and dislodge the material therefrom. The shaft 148 is given a slow rotary movement. The guards 149 are rovided to direct the material to the mid e of the belt conveyor 72 and to direct the lower ends of the rods against the conveyor blades and chain. The guards 149 also cause the rods to strike a ainst each other and keep them clear of temuddy material.

In Figs. 18 to 22 is illustrated mechanism for collecting the valuable caking material from the dust, which` has been found to be particularly eiective for such purpose.

he mechanism consists of rods rotatably mounted in the llue through which the heated ses from the kilns pass. The rods are pre erably of iron or steel and areV illustrated as hung vertical in the flue. These rods become heated by the gases to about the temperature of the gases, so as to present the hot surfaces which have been found effective for collecting the caking material. By rotating the rods they can be made to more eil'ectivel collect the caking material. If a rod is he d stationary in the path of the gases, a limited amount of material will collect, the geater part of which is deposited on the opposite side of the rodfrom that which the current of gas strikes. This is indicated in Fig. 18, where the views show successive building up of the caking formation a at the side of the rod o ite that upon which the gases impinge. have found that by turning the rod slowly the material will build up around it and the capacity of the rod for collecting the caking 'material is thereb greatly increased. This is illustrated in ig. 19, in which the arrows indicate a clockwise direction of rotation or turning, and the successive cross sections illustrate the building up of the cake material b around the entire circum. ference of the rod. A distinct separation of the caking material from the remainder of the dust is assisted by the rotation of the rod, as any dust which will not cake will be blown away from the rod when the rod is revolved to a position where the gases produce a swee ing effect on that part of the rod where the dust has lodged.

In Figs. 20, 21 and 22 I have shown a screen formed of these turning rods, which I may use in an of the (lues near the kilns. In this form a -bar carrier 74 supports a series of rods 75, these rods having gear wheels '76 arranged at alternate levels so that a driving mechanism may be used for those ends of the rods projecting above the flue to rotate the portions hanging within the `Hue and on which the caking material collects. The lower ends of these rods are shown as having bearings in a bar 77, which holds them in' spaced relation. These

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