US3656722A - Apparatus for preheating fine granular material - Google Patents
Apparatus for preheating fine granular material Download PDFInfo
- Publication number
- US3656722A US3656722A US41286A US3656722DA US3656722A US 3656722 A US3656722 A US 3656722A US 41286 A US41286 A US 41286A US 3656722D A US3656722D A US 3656722DA US 3656722 A US3656722 A US 3656722A
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- eddy
- level
- chambers
- chamber
- gas
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- 239000008187 granular material Substances 0.000 title claims description 6
- 239000007789 gas Substances 0.000 claims abstract description 49
- 239000000463 material Substances 0.000 claims abstract description 28
- 238000000926 separation method Methods 0.000 claims description 6
- 239000007787 solid Substances 0.000 claims description 6
- 230000006866 deterioration Effects 0.000 claims description 4
- 238000007599 discharging Methods 0.000 claims description 2
- 230000014759 maintenance of location Effects 0.000 description 3
- 239000000428 dust Substances 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 1
- 231100001261 hazardous Toxicity 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B7/00—Rotary-drum furnaces, i.e. horizontal or slightly inclined
- F27B7/20—Details, accessories or equipment specially adapted for rotary-drum furnaces
- F27B7/2016—Arrangements of preheating devices for the charge
- F27B7/2025—Arrangements of preheating devices for the charge consisting of a single string of cyclones
Definitions
- the invention relates to an apparatus for the preheating of fine granular material by means of hot gases, consisting of a plurality of eddy chambers of the cyclone type arranged at several superimposed levels, wherein the hot gas stream which is distributed to the eddy chambers of the first, lowermost stage is reunited in a central eddy chamber of the second stage, before it is again distributed to the eddy chambers of the third stage, while the divided stream of material coming from the eddy chambers of the third stage is united in the central eddy chamber of the second stage, before it is again distributed to the eddy chambers of the first stage.
- the object of the invention accordingly is to construct an apparatus of the type which has been described in such a manner that the difficulty which has been mentioned is eliminated.
- this object is achieved by providing the cyclone-type eddy chambers with dip pipes in at least one stage, and by constructing the eddy chambers without dip pipes in at least one stage lying in a zone of higher gas temperature.
- the material discharge ducts of the eddy chambers are provided with shutoff devices, and in at least one of the stages which lie in a zone of higher gas temperature the material discharge ducts of the eddy chambers are constructed without shutoff devices.
- shutoff devices which are ordinarily provided in the material discharge ducts are subject to a substantial mechanical and thermal deterioration. This undesirable source of trouble is likewise eliminated by omission of the shutoff devices in the hottest stages of the preheater.
- the retention of these shutoff devices in at least one cooler stage of the preheater, preferably in the uppermost stage, guarantees on the other hand, in conjunction with the retention of the dip pipes in these stages, the good separating capacity which is necessary for a complete separation of dust from the gas stream.
- the open cross section of the material discharge ducts which are constructed without shutoff devices is advantageously made at least great enough so that a maximum of percent, preferably a maximum of 50 percent of the cross section is occupied by material, and at the most great enough so that in total a maximum of 10 percent, preferably a maximum of 5 percent of the entire gas stream passes through the material discharge ducts of this stage.
- the drawing is a schematic longitudinal section of a preferred form of apparatus embodying the invention DESCRIPTION OF THE PREFERRED EMBODIMENT
- the illustrated apparatus serves for the preheating of fine granular material, which is finally supplied to a rotary kiln l.
- the preheater comprises several eddy chambers arranged in superimposed levels, which are constructed like cyclone separators, and are referred to hereinafter as cyclone separators for the sake of simplicity.
- the lowermost stage of the preheater consists of the cyclone separators 2, 2, the second stage consists of one central cyclone separator 3, the third stage consists of two cyclone separators 4, 4' and the fourth stage consists of two cyclone separators 5, 5.
- cyclone separators are connected by means of their gas and material ducts as follows: the gas duct 6 coming from the rotary kiln l is divided and leads to both of the cyclone separators 2, and 2. Their gas discharge ducts 7, 7' both discharge into the central cyclone separator 3, and preferably are tangential in the same sense of rotation.
- the gas discharge duct 8 of the cyclone separator 3 is divided and leads to the cyclone separators 4 and 4', which are connected by means of 7 their gas discharge pipes 9, 9' with the cyclone separators 5, 5'.
- the gas discharge ducts l0, 10 of the latter cyclone separators are connected to a common blower 11.
- the material discharge ducts l2, 12 of the cyclone separators 5, 5 discharge into the gas duct 8.
- the material discharge ducts 13, 13' of the cyclone separators 4, 4' are connected to the gas ducts 7, 7, while the material discharge 14 of the cyclone separator 3 discharges into the upper end of the gas duct 6.
- the material discharge ducts 15, 15 of the two lowermost cyclone separators are directly connected with the rotary kiln 1 or with its inlet housing.
- shutoff devices 12a, l2'a, 13a, 13'a for example in the form of balanced dampers
- Suchdevices are lacking in the material discharge ducts 14, 15 and 15' of the two lower preheater stages.
- Both cyclone separators 2, 2' of the lowermost preheater stages furthermore are constructed without dip pipes, while all of the other cyclone separators 3, 4, 4', 5, 5' are provided with the usual dip pipes 3a, 4a, 4a, 5a, and 5'a.
- the path of flow of the hot gases coming from the rotary kiln 1 is indicated by arrows 17; the hot gas stream is distributed first to the two cyclone separators 2, 2', is then reunited in the central cyclone separator 3, is distributed anew to the cyclone separators 4, 4 then passes through the cyclone separators 5, 5' and is finally withdrawn through the blower 1 1.
- the countercurrent path of the material being preheated is marked by the arrows 18: the material entering the gas ducts 9, 9' is separated in the cyclone separators 5, 5, then travels into the gas duct 8, is led to the cyclone separators 4, 4, travels after separation in these cyclone separators into the gas ducts 7, 7 is brought together anew in the central cyclone separator 3 and is once more distributed, after entering the gas duct 6, to the two cyclone separators 2, 2', before it travels, highly preheated, into the rotary kiln 1.
- Apparatus for preheating fine granular material by means of hot gases comprising a plurality of eddy chambers of the cyclone separator type, arranged in superimposed levels through which the material passes downward in series and through which the hot gases travel upward in series, each eddy chamber of the cyclone separator type having a lateral gas inlet which is located adjacent to the top of the eddy chamber and which is directed to cause the entering gas to eddy in cy'clonefashion so as to separate solids from the gas by centrifugal force, and each eddy chamber also having a lower portion that tapers downward to a bottom outlet for discharging separated solids, wherein the improvement comprises a central vertical gas outlet duct at the top of each eddy chamber, the lower end of such outlet duct of each eddy chamber in at least the uppermost level being extended downward into the eddy chamber in order to improve the separation of solids, and the lower end of the gas outlet duct of each eddy chamber in at least the lowermost level terminating
- Apparatus according to claim 1 wherein the eddy chambers are arranged in at least three superimposed levels, the first and third levels from the bottom each comprising two eddy chambers, and the second level from the bottom comprising only one eddy chamber having two gas inlet ducts, which lead from the two eddy chambers of the first level and into each of which discharges a material supply duct leading from one of the eddy chambers of the third level.
- a fourth level from the bottom comprises two eddy chambers each of which has a gas inlet duct leading from one of the eddy chambers of the third level, the latter eddy chambers being connected to a gas inlet duct, which leads from the eddy chamber of the second level and into which discharge two material supply ducts leading from the eddy chambers of the fourth level, each of such material supply ducts being providedwith a shutoff device.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Cyclones (AREA)
Abstract
A plurality of eddy chambers of the cyclone separator type are arranged in superimposed levels through which the material passes downward in series and through which the hot gases travel upward in series. Each eddy chamber in at least the uppermost level is provided with a dip pipe, and each eddy chamber in at least the lowermost level is constructed without any dip pipe.
Description
United States Patent Polysius et al.
[151 3,656,722 [451 Apr. 18, 1972 [54] APPARATUS FOR PREHEATING FINE GRANULAR MATERIAL [72] Inventors: Jochen Polysius; Horst Ritzrnann, both of Neubeckum, Germany [73} Assignee: Polysius AG, Neubeckum, Germany [22] Filed: May 28, 1970 [2 l] Appl. No.: 41,286 [30] Foreign Application Priority Data Aug. 12, 1969 Germany ..P 19 41 071.0 [52] US. Cl. ..263/21 A, 34/57 R [51] Int. Cl ....F27b 15/00, F26b 17/00 [58] Field of Search ..263/32 R, 21 A; 34/57 R [56] References Cited UNITED STATES PATENTS 3,364,583 1/1968 Friedrich ..263/32 3,317,201 5/1967 Muller et al. ..263/32 3,452,968 7/1969 Shimizu et al ..263/32 X Primary Examiner-John J. Camby Attorney-Marshall & Yeasting [5 7] ABSTRACT A plurality of eddy chambers of the cyclone separator type are arranged in superimposed levels through which the material passes downward in series and through which the hot gases travel upward in series. Each eddy chamber in at least the uppennost level is provided with a dip pipe, and each eddy chamber in at least the lowermost level is constructed without any dip pipe.
4 Claims, 1 Drawing Figure BACKGROUND OF THE INVENTION The invention relates to an apparatus for the preheating of fine granular material by means of hot gases, consisting of a plurality of eddy chambers of the cyclone type arranged at several superimposed levels, wherein the hot gas stream which is distributed to the eddy chambers of the first, lowermost stage is reunited in a central eddy chamber of the second stage, before it is again distributed to the eddy chambers of the third stage, while the divided stream of material coming from the eddy chambers of the third stage is united in the central eddy chamber of the second stage, before it is again distributed to the eddy chambers of the first stage.
In the known preheaters of this type the eddy chambers are in the form of cyclone separators which are provided as usual with dip pipes. In practice it is found, however, that particulady in the high temperature zone of the preheater, i.e. in the lowermost stage, the dip pipes of the cyclone separators are subjected to extraordinarily severe thermal and mechanical deterioration. In many cases, the dip pipes of the lowermost cyclone separators are already burned out after a relatively short period of operation, and this has necessitated difficult repairs heretofore, which often bring about lengthy shutdowns of the entire installation.
SUMMARY OF THE INVENTION The object of the invention accordingly is to construct an apparatus of the type which has been described in such a manner that the difficulty which has been mentioned is eliminated.
In accordance with the invention, this object is achieved by providing the cyclone-type eddy chambers with dip pipes in at least one stage, and by constructing the eddy chambers without dip pipes in at least one stage lying in a zone of higher gas temperature.
When the dip pipes are eliminated, particularly in the lowermost stages of the preheater which are subjected to the highest gas temperature, an undesirable and hazardous source of trouble is thereby eliminated. As shown by tests, the omission of the dip pipes impairs only insignificantly the separating capacity in the cyclone separators in question. Moreover, in the lower stages of the preheater a somewhat prolonged dwell time of the material in the hot gas stream is even very desirable for an intensive exchange of heat in most cases. The retention of the dip pipes in the less intensively heated stages of the preheater, particularly in the uppermost stage of the preheater, guarantees on the other hand the complete separation of the material from the gas stream leaving the preheater.
Accordingly, in the practice of the invention there is achieved a substantial improvement in reliability of operation and freedom from shutdowns of the installation, with simultaneous preservation of a good rate of heat transfer and a complete separation of dust from the gas stream leaving the preheater.
In accordance with a practical embodiment of the invention, in at least one stage the material discharge ducts of the eddy chambers are provided with shutoff devices, and in at least one of the stages which lie in a zone of higher gas temperature the material discharge ducts of the eddy chambers are constructed without shutoff devices.
Like the dip pipes, the shutoff devices which are ordinarily provided in the material discharge ducts are subject to a substantial mechanical and thermal deterioration. This undesirable source of trouble is likewise eliminated by omission of the shutoff devices in the hottest stages of the preheater. The retention of these shutoff devices in at least one cooler stage of the preheater, preferably in the uppermost stage, guarantees on the other hand, in conjunction with the retention of the dip pipes in these stages, the good separating capacity which is necessary for a complete separation of dust from the gas stream.
The open cross section of the material discharge ducts which are constructed without shutoff devices is advantageously made at least great enough so that a maximum of percent, preferably a maximum of 50 percent of the cross section is occupied by material, and at the most great enough so that in total a maximum of 10 percent, preferably a maximum of 5 percent of the entire gas stream passes through the material discharge ducts of this stage.
BRIEF DESCRIPTION OF THE DRAWING The drawing is a schematic longitudinal section of a preferred form of apparatus embodying the invention DESCRIPTION OF THE PREFERRED EMBODIMENT The illustrated apparatus serves for the preheating of fine granular material, which is finally supplied to a rotary kiln l. The preheater comprises several eddy chambers arranged in superimposed levels, which are constructed like cyclone separators, and are referred to hereinafter as cyclone separators for the sake of simplicity. The lowermost stage of the preheater consists of the cyclone separators 2, 2, the second stage consists of one central cyclone separator 3, the third stage consists of two cyclone separators 4, 4' and the fourth stage consists of two cyclone separators 5, 5.
These cyclone separators are connected by means of their gas and material ducts as follows: the gas duct 6 coming from the rotary kiln l is divided and leads to both of the cyclone separators 2, and 2. Their gas discharge ducts 7, 7' both discharge into the central cyclone separator 3, and preferably are tangential in the same sense of rotation. The gas discharge duct 8 of the cyclone separator 3 is divided and leads to the cyclone separators 4 and 4', which are connected by means of 7 their gas discharge pipes 9, 9' with the cyclone separators 5, 5'. The gas discharge ducts l0, 10 of the latter cyclone separators are connected to a common blower 11.
The material discharge ducts l2, 12 of the cyclone separators 5, 5 discharge into the gas duct 8. The material discharge ducts 13, 13' of the cyclone separators 4, 4' are connected to the gas ducts 7, 7, while the material discharge 14 of the cyclone separator 3 discharges into the upper end of the gas duct 6. The material discharge ducts 15, 15 of the two lowermost cyclone separators are directly connected with the rotary kiln 1 or with its inlet housing.
While the material discharge ducts l2, l2 and 13, 13+ of the two uppermost stages of the preheater are provided with shutoff devices 12a, l2'a, 13a, 13'a, for example in the form of balanced dampers, suchdevices are lacking in the material discharge ducts 14, 15 and 15' of the two lower preheater stages. Both cyclone separators 2, 2' of the lowermost preheater stages furthermore are constructed without dip pipes, while all of the other cyclone separators 3, 4, 4', 5, 5' are provided with the usual dip pipes 3a, 4a, 4a, 5a, and 5'a.
The path of flow of the hot gases coming from the rotary kiln 1 is indicated by arrows 17; the hot gas stream is distributed first to the two cyclone separators 2, 2', is then reunited in the central cyclone separator 3, is distributed anew to the cyclone separators 4, 4 then passes through the cyclone separators 5, 5' and is finally withdrawn through the blower 1 1.
The countercurrent path of the material being preheated is marked by the arrows 18: the material entering the gas ducts 9, 9' is separated in the cyclone separators 5, 5, then travels into the gas duct 8, is led to the cyclone separators 4, 4, travels after separation in these cyclone separators into the gas ducts 7, 7 is brought together anew in the central cyclone separator 3 and is once more distributed, after entering the gas duct 6, to the two cyclone separators 2, 2', before it travels, highly preheated, into the rotary kiln 1.
We claim:
1. Apparatus for preheating fine granular material by means of hot gases, comprising a plurality of eddy chambers of the cyclone separator type, arranged in superimposed levels through which the material passes downward in series and through which the hot gases travel upward in series, each eddy chamber of the cyclone separator type having a lateral gas inlet which is located adjacent to the top of the eddy chamber and which is directed to cause the entering gas to eddy in cy'clonefashion so as to separate solids from the gas by centrifugal force, and each eddy chamber also having a lower portion that tapers downward to a bottom outlet for discharging separated solids, wherein the improvement comprises a central vertical gas outlet duct at the top of each eddy chamber, the lower end of such outlet duct of each eddy chamber in at least the uppermost level being extended downward into the eddy chamber in order to improve the separation of solids, and the lower end of the gas outlet duct of each eddy chamber in at least the lowermost level terminating flush with the top of the eddy chamber in order to protect the duct from thermal deterioration.
2. Apparatus according to claim 1 wherein the eddy chambers are arranged in at least three superimposed levels, the lower end of the central vertical gas outlet duct of each eddy chamber above the lowermost level being extended downward into the eddy chamber. 7
3. Apparatus according to claim 1 wherein the eddy chambers are arranged in at least three superimposed levels, the first and third levels from the bottom each comprising two eddy chambers, and the second level from the bottom comprising only one eddy chamber having two gas inlet ducts, which lead from the two eddy chambers of the first level and into each of which discharges a material supply duct leading from one of the eddy chambers of the third level.
4. Apparatus according to claim 3 wherein a fourth level from the bottom comprises two eddy chambers each of which has a gas inlet duct leading from one of the eddy chambers of the third level, the latter eddy chambers being connected to a gas inlet duct, which leads from the eddy chamber of the second level and into which discharge two material supply ducts leading from the eddy chambers of the fourth level, each of such material supply ducts being providedwith a shutoff device.
Claims (4)
1. Apparatus for preheating fine granular material by means of hot gases, comprising a plurality of eddy chambers of the cyclone separator type, arranged in superimposed levels through which the material passes downward in series and through which the hot gases travel upward in series, each eddy chamber of the cyclone separator type having a lateral gas inlet which is located adjacent to the top of the eddy chamber and which is directed to cause the entering gas to eddy in cyclone fashion so as to separate solids from the gas by centrifugal force, and each eddy chamber also having a lower portion that tapers downward to a bottom outlet for discharging separated solids, wherein the improvement comprises a central vertical gas outlet duct at the top of each eddy chamber, the lower end of such outlet duct of each eddy chamber in at least the uppermost level being extended downward into the eddy chamber in order to improve the separation of solids, and the lower end of the gas outlet duct of each eddy chamber in at least the lowermost level terminating flush with the top of the eddy chamber in order to protect the duct from thermal deterioration.
2. Apparatus according to claim 1 wherein the eddy chambers are arranged in at least three superimposed levels, the lower end of the central vertical gas outlet duct of each eddy chamber above the lowermost level being extended downward into the eddy chamber.
3. Apparatus according to claim 1 wherein the eddy chambers are arranged in at least three superimposed levels, the first and third levels from the bottom each comprising two eddy chambers, and the second level from the bottom comprising only one eddy chamber having two gas inlet ducts, which lead from the two eddy chambers of the first level and into each of which discharges a material supply duct leading from one of the eddy chambers of the third level.
4. Apparatus according to claim 3 wherein a fourth level from the bottom comprises two eddy chambers each of which has a gas inlet duct leading from one of the eddy chambers of the third level, the latter eddy chambers being connected to a gas inlet duct, which leads from the eddy chamber of the second level and into which discharge two material supply ducts leading from the eddy chambers of the fourth level, each of such material supply ducts being provided with a shutoff device.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19691941071 DE1941071A1 (en) | 1969-08-12 | 1969-08-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3656722A true US3656722A (en) | 1972-04-18 |
Family
ID=5742611
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US41286A Expired - Lifetime US3656722A (en) | 1969-08-12 | 1970-05-28 | Apparatus for preheating fine granular material |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US3656722A (en) |
| DE (1) | DE1941071A1 (en) |
| FR (1) | FR2056869A5 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3836323A (en) * | 1971-12-02 | 1974-09-17 | Smidth & Co As F L | Pre-heating apparatus in rotary kiln plant |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3317201A (en) * | 1964-04-13 | 1967-05-02 | Polysius Gmbh | Method of and arrangement for increasing the alkali content in alkali-laden dusts of flue gases |
| US3364583A (en) * | 1964-01-31 | 1968-01-23 | Miag Muehlenbau & Ind Gmbh | Method and apparatus for the continuous treatment of granular and/or powdered material with steam and/or gas |
| US3452968A (en) * | 1966-10-12 | 1969-07-01 | Ishikawajima Harima Heavy Ind | Roasting process of fine ore and a device therefor |
-
1969
- 1969-08-12 DE DE19691941071 patent/DE1941071A1/de not_active Withdrawn
-
1970
- 1970-05-28 US US41286A patent/US3656722A/en not_active Expired - Lifetime
- 1970-08-11 FR FR7029594A patent/FR2056869A5/fr not_active Expired
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3364583A (en) * | 1964-01-31 | 1968-01-23 | Miag Muehlenbau & Ind Gmbh | Method and apparatus for the continuous treatment of granular and/or powdered material with steam and/or gas |
| US3317201A (en) * | 1964-04-13 | 1967-05-02 | Polysius Gmbh | Method of and arrangement for increasing the alkali content in alkali-laden dusts of flue gases |
| US3452968A (en) * | 1966-10-12 | 1969-07-01 | Ishikawajima Harima Heavy Ind | Roasting process of fine ore and a device therefor |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3836323A (en) * | 1971-12-02 | 1974-09-17 | Smidth & Co As F L | Pre-heating apparatus in rotary kiln plant |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2056869A5 (en) | 1971-05-14 |
| DE1941071B2 (en) | 1971-01-28 |
| DE1941071A1 (en) | 1971-01-28 |
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