US3926651A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for use in firing raw material for cement
Assignee: Kobe Steel Ltd
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Filing: 1973-12-05
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Granted: 1975-12-16
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Expires: 1993-12-05
Abstract
Abstract A method and an apparatus are disclosed for use in firing the raw materials for producing cement wherein a combination of a rotary kiln and a preheating device of a counter-flow type heat exchange system are utilized. The difficulties and drawbacks previously encountered with such type heat exchange systems, such as instabilities in flow and heat control, are avoided by the use of proper temperature adjustment, the application of additional heat, powdery-material preheating apparatus including a divergent nozzle and controls of the flow speed of a hot gas passing through the aforesaid system, thereby achieving considerable thermal economy and improved yield of cement per plant, without resorting to increase in the size of the rotary kiln.
Inventors
- 👤 Yoshihiro Ichikawa
- 👤 Tetsuo Fujisawa
- 👤 Yoshiro Seo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:26
CPC Classifications
C; C04; C04B; C04B7/00; C04B7/36; C04B7/43; C04B7/434
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
241 words
A METHOD FOR USE IN FIRING RAW MATERIAL FOR USE IN THE PRODUCTION OF CEMENT, UTILIZING A COMBINATION OF A COUNTERFLOW TYPE PREHEATING DEVICE WITH AN UPWARDLY DIVERGENT CONFIGUREATION FOR PREHEATING RAW MATERIAL OF CEMENT, A ROTARY KILN FOR FIRING THE RAW MATERIAL PREHEATED IN SAID PREHEATING DEVICE AND A COOLING DEVICE FOR COOLING BURNT CLINKER PRODUCED AS THE RESULT OF FIRING THE PREHEATED RAW MATERIAL IN SAID ROTARY KILN, IN WHICH AIR ACTS AS A COOLANT IS A COOLING DEVICE AND IS SUBSEQUENTLY HEATED, COMPRISING THE STEPS OF: WITHDRAWING AND FURTHER HEATING AIR WITH HOT GAS BEING DIRECTLY COOLING DEVICE; MIXING SAID FURTHER HEATED AIR WITH HOT GAS BEING DIRECTLY EXHAUSTED FROM SAID ROTARY KILN, THEREBY ADJUSTING THE TEMPERATURE OF SAID MIXED GAS BEING SO FORMED SO AS TO BE HIGHER THAN THAT OF THE RAW MATERIAL HEATED IN SAID PREHEATING DEVICE; INTRODUCING SAID MIXED GAS INTO THE BOTTOM OF SAID UPWARDLY DIVERGENT PREHEATING DEVICE IN AN ASCENDING MANNER; FEEDING POWDERY RAW MATERIAL INTO SAID PREHEATING DEVICE FROM ABOVE SO S TO FLOW DOWNWARDLY IN A COUNTER-FLOW MANNER WITH RESPECT TO SAID ASCENDING MIXED GAS; AND SUPPLYING FUEL INTO SAID PREHEATING DEVICE TO BURN THE SAME WITH SAID MIXED GAS, WHEREBY COMENT RAW MATERIAL IN A POWDER FROM FLOWING THEREIN AND CARRIED ON THE GAS FLOW THEREIN MAY BE CALCINATED AND CUASED TO FLOW DOWNWARDLY AGAINST THE ASCENDING FLOW OF SAID MIXED GAS FOR BEING FED INTO SAID ROTARY KLIN.
Claim 2
Independent Claim
241 words
A METHOD FOR USE IN FIRING RAW MATERIAL FOR USE IN THE PRODUCTION OF CEMENT, UTILIZING A COMBINATION OF A COUNTERFLOW TYPE PREHEATING DEVICE WITH AN UPWARDLY DIVERGENT CONFIGUREATION FOR PREHEATING RAW MATERIAL OF CEMENT, A ROTARY KILN FOR FIRING THE RAW MATERIAL PREHEATED IN SAID PREHEATING DEVICE AND A COOLING DEVICE FOR COOLING BURNT CLINKER PRODUCED AS THE RESULT OF FIRING THE PREHEATED RAW MATERIAL IN SAID ROTARY KILN, IN WHICH AIR ACTS AS A COOLANT IS A COOLING DEVICE AND IS SUBSEQUENTLY HEATED, COMPRISING THE STEPS OF: WITHDRAWING AND FURTHER HEATING AIR WITH HOT GAS BEING DIRECTLY COOLING DEVICE; MIXING SAID FURTHER HEATED AIR WITH HOT GAS BEING DIRECTLY EXHAUSTED FROM SAID ROTARY KILN, THEREBY ADJUSTING THE TEMPERATURE OF SAID MIXED GAS BEING SO FORMED SO AS TO BE HIGHER THAN THAT OF THE RAW MATERIAL HEATED IN SAID PREHEATING DEVICE; INTRODUCING SAID MIXED GAS INTO THE BOTTOM OF SAID UPWARDLY DIVERGENT PREHEATING DEVICE IN AN ASCENDING MANNER; FEEDING POWDERY RAW MATERIAL INTO SAID PREHEATING DEVICE FROM ABOVE SO S TO FLOW DOWNWARDLY IN A COUNTER-FLOW MANNER WITH RESPECT TO SAID ASCENDING MIXED GAS; AND SUPPLYING FUEL INTO SAID PREHEATING DEVICE TO BURN THE SAME WITH SAID MIXED GAS, WHEREBY COMENT RAW MATERIAL IN A POWDER FROM FLOWING THEREIN AND CARRIED ON THE GAS FLOW THEREIN MAY BE CALCINATED AND CUASED TO FLOW DOWNWARDLY AGAINST THE ASCENDING FLOW OF SAID MIXED GAS FOR BEING FED INTO SAID ROTARY KLIN.
Claim 3
Dependent Claim
91 words
A method as defined in claim 1, wherein said method further comprises: supplying heat of no more than 10% of the total heat to be supplied to the entire process to the hot air from said cooling device, to thereby raise the temperature of said hot air; supplying said fuel in an amount to produce heat of 30 to 70% of the total heat required for the entire process into said preheating device; and supplying the remaining heat of said total heat to said raw material being introduced in said kiln.
Claim 4
Dependent Claim
58 words
A method as defined in claim 2, wherein the heat supplied to the hot gas from said cooling device is in the range Of 3 to 8% of the total heat required for the entire process, and the heat supplied to said upwardly divergent preheating device is in the range of 50 to 65% of said total heat.
Claim 5
Dependent Claim
45 words
A method as defined to claim 1, wherein the speed of axial flow of the mixed gas within said upwardly divergent preheating device is in the range from 20 to 30 m/s at the smallest cross-sectional area of the lower part of said preheating device.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |