Patent US2481294A successfully refreshed from Google Patents.
US4043746A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the heat treatment of fine-grained materials containing alkali compounds
Assignee: ThyssenKrupp Industrial Solutions AG
•
Filing: 1976-04-23
•
Granted: 1977-08-23
•
Expires: 1996-04-23
Abstract
Abstract A method for the heat treatment of fine-grained materials containing alkali compounds which liquify at critical temperatures comprises pre-heating the materials and discharging them to a rotary kiln in counterflow to the kiln exhaust gases, and introducing cooling air to the kiln in such quantity and at such temperature as to reduce the temperature of the exhaust gases to a level lower than that required for the compounds to liquify.
Inventors
- 👤 Horst Ritzmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 16:06
CPC Classifications
F; F27; F27B; F27B7/00; F27B7/20; F27B7/2016; F27B7/2025; C; C04; C04B; C04B7/00; C04B7/36; C04B7/43; C04B7/44
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
188 words
A two-stage method of sintering fine-grained raw cement meal containing a solid compound which at a critical temperature lower than the sintering temperature of said material tends to liquify and form deposits, said solid compound being from the group composed of SiO 2 , Al 2 O 3 , TiO 2 , Fe 2 O 3 , Mn 2 O 3 , CaO, MgO, SO 3 , P 2 O 5 , Na 2 O, K 2 O, Cl, and mixtures thereof, said method comprising discharging said material from a preheater to one end of a sintering kiln; directing through said kiln from the other end thereof toward said one end hot gases at a temperature sufficiently high to sinter said material; exhausting the gases from said kiln to said preheater to preheat said material prior to its discharge to said one end of said kiln; and introducing cooling air into said kiln adjacent said one end thereof in sufficient quantity and at such temperature to ensure that the temperature of the gases exhausted from said kiln to said preheater is lower than that of said critical temperature.
Claim 2
Dependent Claim
188 words
A two-stage method of sintering fine-grained raw cement meal containing a solid compound which at a critical temperature lower than the sintering temperature of said material tends to liquify and form deposits, said solid compound being from the group composed of SiO 2 , Al 2 O 3 , TiO 2 , Fe 2 O 3 , Mn 2 O 3 , CaO, MgO, SO 3 , P 2 O 5 , Na 2 O, K 2 O, Cl, and mixtures thereof, said method comprising discharging said material from a preheater to one end of a sintering kiln; directing through said kiln from the other end thereof toward said one end hot gases at a temperature sufficiently high to sinter said material; exhausting the gases from said kiln to said preheater to preheat said material prior to its discharge to said one end of said kiln; and introducing cooling air into said kiln adjacent said one end thereof in sufficient quantity and at such temperature to ensure that the temperature of the gases exhausted from said kiln to said preheater is lower than that of said critical temperature.
Claim 3
Dependent Claim
133 words
A two-stage heat treatment method of treating fine-grained raw material having a sintering temperature and containing a solid compound which at a critical temperature lower than said sintering temperature tends to liquify and form deposits, said method comprising directing through a sintering kiln from one end thereof toward the other hot gases at a temperature higher than said critical temperature; preheating said material by exhausting the gases from said kiln to a preheater to which said material is introduced and subsequently delivered to said other end of said kiln; and introducing cooling air into said kiln adjacent said other end thereof in sufficient quantity and at such temperature as to ensure that the temperature of the gases exhausted from said kiln to said preheater is at a temperature lower than said critical temperature.
Claim 4
Dependent Claim
133 words
A two-stage heat treatment method of treating fine-grained raw material having a sintering temperature and containing a solid compound which at a critical temperature lower than said sintering temperature tends to liquify and form deposits, said method comprising directing through a sintering kiln from one end thereof toward the other hot gases at a temperature higher than said critical temperature; preheating said material by exhausting the gases from said kiln to a preheater to which said material is introduced and subsequently delivered to said other end of said kiln; and introducing cooling air into said kiln adjacent said other end thereof in sufficient quantity and at such temperature as to ensure that the temperature of the gases exhausted from said kiln to said preheater is at a temperature lower than said critical temperature.
Claim 5
Dependent Claim
40 words
A method according to claim 2 including introducing said air to said kiln at a sufficient distance from said other end thereof that a substantially homogeneous mixture of air and exhaust gases exists at said other end of said kiln.
Claim 6
Dependent Claim
34 words
A method according to claim 2 including introducing said air to said kiln at a distance from said other end thereof which is between about two to three times the diameter of said kiln.
Claim 7
Dependent Claim
14 words
A method according to claim 2 including forcibly blowing said air into said kiln.
Claim 8
Dependent Claim
16 words
A method according to claim 2 including varying the quantity of air introduced to said kiln.
Claim 9
Dependent Claim
13 words
A method according to claim 2 wherein said raw material is cement meal.
Claim 10
Dependent Claim
31 words
A method according to claim 2 including maintaining the temperature of said gases adjacent said one end of said kiln at least as high as the sintering temperture of said material.
References Cited (Backward Citations)
US1350750A
Cited
US1071303A
Cited
US2590090A
Cited
US2743918A
Cited
US2754197A
Cited
US3188751A
Cited
US3584850A
Cited
US3595543A
Cited
US3888621A
Cited
US3966560A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-22 | 1981-02-21 | 1981-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-22 | 1985-02-21 | 1985-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-22 | 1989-02-21 | 1989-08-23 | $7700.00 | Window Closed / Lapsed |