US3925091A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and an apparatus for burning the material for the manufacture of cement
Assignee: Taiheiyo Cement Corp
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Filing: 1975-03-28
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Granted: 1975-12-09
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Expires: 1995-03-28
Abstract
Abstract A method and an apparatus for burning the material for the manufacture of cement, which comprises: setting up a calcining zone by forming a constriction in the charging-end duct of the kiln, providing a riser duct with a conicylindrical lower portion on the constriction, connecting a secondary-air intake duct to the riser duct, and installing inside the riser duct a combustion system so positioned as to inject fuel toward the center of the duct; disposing the calcining zone between the suspension preheater and the kiln; introducing the material preheated by the suspension preheater into the upper end of the calcining zone, while, at the same time, supplying secondary air for combustion of fuel to the riser duct, thus calcining the material with the ascending, swirling stream of the resulting combustion gas; and then separating the calcined material from the exhaust gas in a separator and feeding the material to the kiln.
Inventors
- 👤 Eiji Yoshida
- 👤 Yoshimasa Hayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 01:50
CPC Classifications
F; F27; F27B; F27B7/00; F27B7/20; F27B7/2016; F27B7/2025; F27B7/2033; C; C04; C04B; C04B7/00; C04B7/36; C04B7/43; C04B7/434
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
177 words
IN A METHOD OF BURNING CEMENT MATERIAL USING A ROTARY KILN WITH THE ATTACHMENT OF A SUSPENSION PREHEATER EQUIPPED WITH A MATERIAL BURNING FURNACE, SAID METHOD COMPRISING FORMING A CONSTRICTION IN THE CHARGING-END DUCT OF A ROTARY KILN, CONNECTING A RISER DUCT FORMED OF A STRAIGHTLY CYLINDRICAL UPPER BODY PORTION AND A CONI-CYLINDRICAL LOWER PORTION ONTO SAID CONSTRICTION AT THE CONI-CYLINDRICAL LOWER PORTION SAID RISER DUCT BEING PROVIDED WITH A SECONDARY-AIR INTAKE DUCT FOR UTILIZING AIR EXTRACTED FROM A CLINKER COOLER AND INSTALLING IN THE RISER DUCT A COMBUSTION MEANS SO POSTIONED AS TO INJECT FUEL TOWARDS THE CENTER OF THE DUCT, DISPOSISNG A CALCINING ZONE THUS SET UP BY SAID COMBUSTION MEANS BETWEEEN THE SUSPENSION PREHEATER AND KILN INTRODUCING THE MATERIAL PREHEATED BY THE SUSPENSION PREHEATER INTO THE UPPER END OF THE CALCINING ZONE, WHILE, AT THE SAMIE TIME, SUPPLYING SECONDARY AIR FOR COMBUSTION OF THE FUEL INTO THE RISER DUCT IN A TANGETINAL DIRECTION SO AS TO FORM A SWIRLING FLOW THEREIN, FLOWING THE EXHAUST GASES FROM SAID KILN THROUGH THE CONSTRICTION TO SUPPLY AN
Claim 2
Dependent Claim
177 words
IN A METHOD OF BURNING CEMENT MATERIAL USING A ROTARY KILN WITH THE ATTACHMENT OF A SUSPENSION PREHEATER EQUIPPED WITH A MATERIAL BURNING FURNACE, SAID METHOD COMPRISING FORMING A CONSTRICTION IN THE CHARGING-END DUCT OF A ROTARY KILN, CONNECTING A RISER DUCT FORMED OF A STRAIGHTLY CYLINDRICAL UPPER BODY PORTION AND A CONI-CYLINDRICAL LOWER PORTION ONTO SAID CONSTRICTION AT THE CONI-CYLINDRICAL LOWER PORTION SAID RISER DUCT BEING PROVIDED WITH A SECONDARY-AIR INTAKE DUCT FOR UTILIZING AIR EXTRACTED FROM A CLINKER COOLER AND INSTALLING IN THE RISER DUCT A COMBUSTION MEANS SO POSTIONED AS TO INJECT FUEL TOWARDS THE CENTER OF THE DUCT, DISPOSISNG A CALCINING ZONE THUS SET UP BY SAID COMBUSTION MEANS BETWEEEN THE SUSPENSION PREHEATER AND KILN INTRODUCING THE MATERIAL PREHEATED BY THE SUSPENSION PREHEATER INTO THE UPPER END OF THE CALCINING ZONE, WHILE, AT THE SAMIE TIME, SUPPLYING SECONDARY AIR FOR COMBUSTION OF THE FUEL INTO THE RISER DUCT IN A TANGETINAL DIRECTION SO AS TO FORM A SWIRLING FLOW THEREIN, FLOWING THE EXHAUST GASES FROM SAID KILN THROUGH THE CONSTRICTION TO SUPPLY AN
Claim 3
Dependent Claim
25 words
A method as claimed in claim 1 wherein the secondary air is tangentially delivered to the straightly cylindrical upper body portion of the riser duct.
Claim 4
Dependent Claim
22 words
A method as claimed in claim 1 wherein the secondary air is tangentially delivered to the coni-cylindrical portion of the riser duct.
Claim 5
Dependent Claim
53 words
A method as claimed in claim 1 wherein the diameter and length of the constriction in the kiln duct are so chosen as to provide no differential between the pressure loss of the gas in the kiln and that of the air extracted from the clinker cooler through the secondary air intake duct.
Claim 6
Dependent Claim
33 words
A method as claimed in claim 1 wherein the flow velocity of the exhaust gas from the kiln is determined depending upon the diameter and length of the constriction in the kiln duct.
Claim 7
Dependent Claim
147 words
In an apparatus for burning the material for the manufacture of cement, including a suspension preheater, a rotary kiln, and a cement clinker cooler, the improvement comprising: a kiln duct formed with a given length of a cylindrical constriction; a riser duct having a coni-cylindrical lower portion and a straightly cylindrical upper body portion, said riser duct being connected at its conical lower end to the upper end of the kiln duct; and said riser duct being connected to a material separator by an exhaust gas outlet duct; a secondary-air intake duct connected to the riser duct; and a combustion system installed inside the riser duct and so positioned as to inject fuel toward the center of the duct; said riser duct being connected at its upper end to the lower end of the suspension preheater, said secondary-air intake duct being connected to the cement clinker cooler.
Claim 8
Dependent Claim
147 words
In an apparatus for burning the material for the manufacture of cement, including a suspension preheater, a rotary kiln, and a cement clinker cooler, the improvement comprising: a kiln duct formed with a given length of a cylindrical constriction; a riser duct having a coni-cylindrical lower portion and a straightly cylindrical upper body portion, said riser duct being connected at its conical lower end to the upper end of the kiln duct; and said riser duct being connected to a material separator by an exhaust gas outlet duct; a secondary-air intake duct connected to the riser duct; and a combustion system installed inside the riser duct and so positioned as to inject fuel toward the center of the duct; said riser duct being connected at its upper end to the lower end of the suspension preheater, said secondary-air intake duct being connected to the cement clinker cooler.
Claim 9
Dependent Claim
22 words
An apparatus as claimed in claim 6 wherein the secondary-air intake duct is connected to the cement clinker cooler via air-extracting means.
Claim 10
Dependent Claim
32 words
An apparatus as claimed in claim 6 wherein the combustion system is installed in the coni-cylindrical portion of the riser duCt and directed obliquely upward and toward the center of the duct.
Claim 11
Dependent Claim
29 words
An apparatus as claimed in claim 6 wherein the combustion system is installed in the straightly cylindrical body portion of the riser duct and directed toward the center thereof.
Claim 12
Dependent Claim
24 words
An apparatus as claimed in claim 6 wherein the secondary-air intake duct is open tangentially in the straightly cylindrical portion of the riser duct.
Claim 13
Dependent Claim
23 words
An apparatus as claimed in claim 6 wherein the secondary-air intake duct is open tangentially in the coni-cylindrical portion of the riser duct.
References Cited (Backward Citations)
US1605279A
Cited
US3452968A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-08 | 1979-06-09 | 1979-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-08 | 1983-06-09 | 1983-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-08 | 1987-06-09 | 1987-12-09 | $7700.00 | Window Closed / Lapsed |