CA1053459A - Cement making apparatus including preheater, kiln, cooler and auxiliary furnace - Google Patents

Cement making apparatus including preheater, kiln, cooler and auxiliary furnace

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Publication number
CA1053459A
CA1053459A CA254,245A CA254245A CA1053459A CA 1053459 A CA1053459 A CA 1053459A CA 254245 A CA254245 A CA 254245A CA 1053459 A CA1053459 A CA 1053459A
Authority
CA
Canada
Prior art keywords
level
auxiliary furnace
kiln
preheater
stage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA254,245A
Other languages
French (fr)
Inventor
Masaaki Takeuchi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Allis Chalmers Corp
Original Assignee
Allis Chalmers Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Allis Chalmers Corp filed Critical Allis Chalmers Corp
Priority to CA254,245A priority Critical patent/CA1053459A/en
Application granted granted Critical
Publication of CA1053459A publication Critical patent/CA1053459A/en
Expired legal-status Critical Current

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Abstract

CEMENT MAKING APPARATUS INCLUDING PREHEATER, KILN, COOLER AND AUXILIARY FURNACE

ABSTRACT OF THE DISCLOSURE
An apparatus is disclosed for producing such as Portland cement from pulverant raw material having a preheater, an auxiliary furnace 22, a rotary kiln 2, a cooler, and a single blower connected to the top of the preheater to draw air and combustion gases through the kiln, auxiliary furnace and preheater. Preheater receives waste gas from the rotary kiln for flow through first, second, third and fourth level cyclones, with the first level cyclone(s) C1 being at an elevation higher than the kiln and the second, third and fourth level cyclones (C2, C3, and C4) each being at successively higher elevations. The auxiliary furnace 22 is preferably at the approximate level of the second level cyclone C2. The auxiliary furnace 22 is fed pulverant material from third level cyclone C3 and discharges pulverant material to a flue leading from the kiln to first level cyclones C1, with both such feed to and discharge from the auxiliary furnace proceeding under the influence of gravity without the need for a second blower to pressurize air from the cooler to the auxiliary furnace as has been necessary with arrangements of such systems known to the prior art before the present invention.

Description

~053459 BACKGROUND''OF THE I~VENTI-ON
Field:of the I~vention This invention relates to an apparatus for pretreat-ing particulate feed material for a rotary kiln with heated exit gases from the kiln, as is utilized, or example, to produce Portland cement. In particular, this invention relates to such preheaters that comprise an assembly of cyclone dust separators and an auxiliary furnace to additi~nally heat feed material after the feed material has been preheated but prior to the feed material entering the rotary kiln.
Descript'ion of the Prior'Art Preheaters for rotary kilns known to the prior art that involve preheating finely divided raw material suspended in and moving generally counter to the flow of heated kiln exit gases flowing through one or more cyclone dust separators are disclosed in such patents as Czechozlovakian patent 48,169 of 1934; published German patent application K 156,877 of 1940; U.S. patents 2,648,532 and 2,663,560 of 1953; many others of such patents are identified in U.S. patent 3,441,258 of 1969 and German Auslegeschrift 1,941,045 published in 1970.
Preheaters of the aforementioned type but which are additionally provided with an auxiliary furnace having one or more auxiliary burners to additionally heat feed material after the feed material-has been preheated but prior to the feed material entering the rotary kiln are disclosed in patents such as U.S. 3,235,239 of 1966; U.S. 3,452,968 of 1969; U.S.
3,834,860 of 1974; U.S. 3,869,248; U.S. 3,873,331; U.S.
3~881J862; U.S. 3,891,382; U.S. 3,891,383; U.S. 3,914,098;
U.S~' 3,925,091 and U.S. 3,926,651, all of 1975; and U.S.

3,932,116 and U.S. 3,'932,117 of. 1976.

- SUMM~:RY OF THE PRESENq~ 7ENTION
The present invention reIates to an improved preheater for pulverant kiln feed material of the type shown in the aforesaid German Auslegeschrift 1,941,045 published December 10, 1970. Such a preheater as therein disclosed and included in the present invention has a pair of cyclones at a first ele-vation above a kiln for receiving waste gas from the kiln which is discharged from the pair of first level cyclones Cl to a single second level cyclone C2 at an elevation above the first level cyclones Cl. The single second level cyclone C2 in turn discharges the kiln waste gas to a pair of third level cyclones C3 at an elevation above the second level cyclones C2. The third level cyclones C3 may discharge kiln waste gas to a pair of top level cyclones C4 (as shown in German Auslege-schrift 1,941,045) or to two pairs of top level cyclones C4 (an arrangement also known to the prior art) which then dis-charge to a common header connected to a blower. Pulverant raw material is fed into the kiln waste gas prior to such gas passing into the top level cyclones C4 and the raw material travels counter to such gases through cyclones C4, C3, C2, Cl, in that order, to be fed to a rotary kiln.
- While it is known to the prior art to feed some of the material discharge from a first level cyclone Cl to an auxiliary furnace before entering the kiln (as per aforesaid U.S. patent 3,881,861) and to similarly direct material from a second level cyclone to an auxiliary furnace, it is an impor-tant feature of the present invention that at least a portion of the pulverant material discharged from the third level cyclone C3 is delivered to an auxiliary furnace that burns fuel in air drawn from a cooler connected to the discharge end of the kiln. The material flowing to the auxiliary furnace is 1053~59 further heated therein and then discharged soley to the kiln waste gas flowing to the inlets of the first level cyclones Cl, thus bypassing the second level cyclones C2. The advantage of this arrangement according to the present invention is that the conduits to and from the auxiliary furnace have sufficient down-ward slope for the pulverant material to flow to and from the auxiliary furnace as a result of its own gravity flow, the entire system operates with a single blower connected to the top level cyclones C4, and no blower is required in the conduit from the cooler to the auxiliary furnace as in the case with the prior art arrangements which feed material from first or second level cyclones Cl or C2 to an auxiliary furnace.
The foregoing and other advantages attained by the present invention will be apparent from the following more detailed description of the present invention with reference to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
The accompanying drawing shows a diagram--materially a side elevation of an embodiment of the present invention with a cooler, preheater, and auxiliary furnace, all according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the preferred embodiment of the invention shown in the drawing, a gas stream for producing such as Portland cement clinker, originates as atmospheric air passing through a clinker cooler 1. A portion of the air which becomes heated by clinker cooling flow through the cooler 1, passes into a rotary kiln 2 having a fuel burner 2a for burning fuel in such air to produce combustion gases. Waste gases from kiln 2 pass into and through a flue 3 to a conduit 4 that delivers such iOS3459 kiln waste gases to a pair of first level cyclones Cl and then a pair of flues 5, 6 to a single second leveI cyclone C2 at an elevation spaced above the level of cyclone Cl. From cyclone C2 the kiln waste gases pass through a flue 7 to a conduit 8 that delivers such gases to a pair of third level cyclones C3 at an elevation spaced above the level of the cyclone C2. The kiln waste gases pass from the two cyclones C3 through flues 9 and 10, respectively, with flue 9 deliver-ing a portion of the kiln waste gases to a conduit 11 and a -first pair of fourth level cyclones C4 while the flue 10delivers another portion of the kiln waste gases to a conduit 12 and a second pair of fourth level cyclones C4. The four fourth level cyclones C4 are each at an elevation spaced above the third level cyclones C3 and discharge through flues 13-16 into a conduit 17 connected to the inlet of a blower 18.
A second portion of air from the cooler 1 is passed through a coarse pulverant separator 19, which may be such as a particle drop-out chamber, and a flue 21 to an auxiliary furnace 22 having a fuel burner 22a. The auxiliary furnace may be such as has been developed by Onoda Cement Co., Ltd.
of Japan and disclosed in Fig. 16 of U.S. patent 3,834,860, and such a furnace ~ischarges combustion gases and pulverant material through a downwardly inclined duct 23 to flue 3.
Pulverant raw material to move through the system counter to the flow of waste kiln gases is fed into the system through a pair of material inlet chutes 30 and 31 which dis-charge into flues 9 and 10, respectively. Kiln waste gases and pulverant feed material then pass into the fourth level cyclones C4. Pulverant material is discharged from the fourth level cyclones C4 through pipes 32 to the conduit 8 and into the pair of third level cyclones C3. Adjustable flow dividers 33, 34 divide pulverant discharged from the two third level cyclones C3 between pipes.35,.36 and 37, 38, respectively.
Material dropping through pipes.35 and.37 passes into the flues 5, 6, respectively, and into the single second level cyclone C2. From the second level cyclone C2 the pulverant material drops through a pipe 39 into an upper portion of the flue 3 where it is carried through the conduit 4 to both of the first level cyclones Cl. Pulverant material drops from the two first level cyclones Cl through pipes 40, 41 into a lower portion of flue 3 and passes through kiln 2 to the cooler 1.
Pulverant material directed by the flow dividers 33, 34, to pass into the pipes 36, 38 because of the considerable downward slope of pipes 36, 38, slides downwardly under the influence of gravity into the auxiliary furnace 22; and because of the considerable downward slope of the inclined duct 23 the pulverant material also slides from the auxiliary furnace 22 under the influence of gravity into the upper portion of flue 3. Pulverant material passing from duct 23 into flue 3 joins with pulverant material dropping therein through pipe 39 to pass through the first level cyclones C
and on through kiln 2 to cooler 1 as has been described.
Thus, according to the present invention, feeding the auxiliary furnace 22 pulverant material from the third level cyclones C3 and discharging pulverant material from the auxiliary furnace 22 to the first level cyclones Cl (i.e., bypassing the second level cyclone C2) provides a downward slope needed for flow through pipes 36, 38 and duct 23 to proceed under the influence of gravity without a need to provide a second blower in the flue 21. Prior art arrange-ments, such as have been referred to, in which either firstlevel Cl or second l.evel C2 cyclones feed an auxiliary furnace, _5_ ~053459 require a second blower because in such arrangements if the pipes feeding pulverant material to the auxiliary furnaces are given sufficient downward slope to cause gravity flow there-through, then the discharge duct from the auxiliary furnace 22 has insufficient slope for gravity feed and a blower is required in flue 21 to blow pulverant material into flue 3;
or if the disGharge duct 23 from the auxiliary furnace has sufficient downward slope to provide gravity flow of the pulverant material therethrough, then the pulverant material delivery pipes to the auxiliary furnace have insufficient slope for gravity flow therethrough and the flue 21 must be connected to such delivery pipes and a second blower must be provided to blow pulverant material into the auxiliary furnace 22.
Thus, with each variation of the described system that was known in this field before the present invention, a second blower was needed with the second blower being arranged to pressurize air from the cooler to the auxiliary furnace.
The system that has been described as being according to the present invention avoids such a need for a second blower and this is an important feature of the present invention.

Claims (3)

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:
1. An apparatus for such as burning pulverant raw material to produce Portland cement in which pulverant feed material and gases follow generally countercurrent paths through a preheater (C1, C2 and C3), an auxiliary furnace (22), a rotary kiln (2), a cooler (1) and a blower (18) connected to the preheaters to draw air and combustion gases through the apparatus: with the preheater having at least a first level stage (C1) at an elevation vertically spaced above the kiln (2), a second level stage (C2) spaced vertically above the first level stage (C1) and a third level stage (C3) spaced vertically above the second level stage (C2); and with both the kiln (2) and the auxiliary furnace (22) being separately connected to the cooler (1) to receive fuel combustion supporting air therefrom; the improvement comprising;
(a) a pulverant material transfer pipe (36 and/or 38) connected on a first end thereof to a pulverant material discharge opening (33) of the third level preheater stage (C3) and on a second end thereof to an inlet of the auxiliary furnace (22) for delivering at least a portion of the pulverant material from the third level stage (C3) to the auxiliary furnace (22);
(b) a pulverant material transfer duct (23) connected on a first end to a material outlet of the auxiliary furnace (22) providing the sole outlet therefrom and on a second end thereof to a flue passage (3, 4) delivering kiln waste gas to the first level preheater stage (C1); and (c) the auxiliary furnace (22) being located at a vertical level between the levels of the first and third level preheater stages (C1 and C3) to provide both the pipe 36 and/or 38) and the duct (23), a downward slope of an angle causing gravity flow of pulverant material through both the pipe and duct.
2. An apparatus according to claim 1 in which the first level preheater stage (C1) comprises a pair of cyclones, the second level preheater stage (C2) comprises a single stage, the third level preheater stage (C3) comprises a pair of cyclones, and a pair of pulverant material transfer pipes (36, 38) are provided with each connecting the discharge of one of the cyclones of the third level preheater stage (C3) to the auxiliary furnace (22).
3. An apparatus according to claim 2 in which the pulverant material discharge opening of each third level (C3) is provided with an adjustable flow divider operative to selectively control and divide the portion of pulverant material flowing therethrough between flows to the auxiliary furnace (22) and to the second level cyclone (C2).
CA254,245A 1976-06-07 1976-06-07 Cement making apparatus including preheater, kiln, cooler and auxiliary furnace Expired CA1053459A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CA254,245A CA1053459A (en) 1976-06-07 1976-06-07 Cement making apparatus including preheater, kiln, cooler and auxiliary furnace

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA254,245A CA1053459A (en) 1976-06-07 1976-06-07 Cement making apparatus including preheater, kiln, cooler and auxiliary furnace

Publications (1)

Publication Number Publication Date
CA1053459A true CA1053459A (en) 1979-05-01

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ID=4106153

Family Applications (1)

Application Number Title Priority Date Filing Date
CA254,245A Expired CA1053459A (en) 1976-06-07 1976-06-07 Cement making apparatus including preheater, kiln, cooler and auxiliary furnace

Country Status (1)

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CA (1) CA1053459A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT13401U1 (en) * 2013-04-11 2013-12-15 A Tec Holding Gmbh Device for removing hot gas

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT13401U1 (en) * 2013-04-11 2013-12-15 A Tec Holding Gmbh Device for removing hot gas

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