Compositions: coating or plastic – Coating or plastic compositions – Inorganic settable ingredient containing
Patent
1997-10-28
1999-09-07
Marcantoni, Paul
Compositions: coating or plastic
Coating or plastic compositions
Inorganic settable ingredient containing
106752, C04B 743
Patent
active
059481587
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
This application is a 371 of PCT/DK95/00320 filed Aug. 3, 1995.
The present invention relates to an apparatus and a method for manufacturing clinker whereby the majority of the raw materials is introduced in a hydrous slurry. The apparatus comprises a gas suspension drier in which the slurry of raw materials is dried and a kiln in which the materials are burned and nodulized.
In connection with the traditional method for manufacturing cement clinker according to a wet process, the raw materials are ground subject to simultaneous addition of water and passed on to the kiln in a slurry so that the drying of the slurry is effected in the first and coldest part of the kiln.
Another possibility involves removal of the water from the raw materials prior to their entry into the kiln. Such a method is described in U.S. Pat. No. 5,173,044 according to which the raw materials are fed to a Gas Suspension Drier (GSD) prior to their entry into the kiln. In this context, the GSD unit is also operating as a scrubber, and, consequently, nearly all of the S0.sub.2 being generated in the kiln is expelled from the exhaust gasses. In this apparatus it is also possible to mix dry and hydrous raw materials in the GSD unit without causing the overall raw material mixture to become inhomogeneous.
However, it has emerged that the temperature profiles experienced during this process will increase the risk of volatile organic compounds being distilled off the raw materials in the first part of the kiln so that they are carried along by the exhaust gases through the GSD unit without being absorbed or destroyed since the temperature in the GSD unit is relatively low.
SUMMARY OF THE INVENTION
It is therefore the object of the invention-to provide a method for manufacturing clinker by means of which emission to the atmosphere of volatile organic compounds entrained in the exhaust gases is avoided.
This object is achieved by leading the exhaust gases from the kiln through a thermal unit in which the temperature is momentarily increased to a level which is sufficiently high for the volatile organic compounds to be destroyed.
The raw materials have a temperature of approximately 120-200.degree. C., on discharge from the GSD unit and in connection with the manufacture of cement clinker this temperature must momentarily be raised beyond 750.degree. C.
When manufacturing cement clinker, it may thus be advantageous to feed the raw materials to a calciner in which the temperature normally is above 800-900.degree. C.
BRIEF DESCRIPTION OF THE DRAWINGS
The FIGURE is a schematic of plant according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Illustrated in the FIGURE is a cement kiln plant which comprises a rotary kiln 1, a gas suspension drier (GSD) 4 with a subsequent separation cyclone 9, and a calciner 3 with a subsequent separation cyclone 5. A raw material slurry is fed to the GSD unit via a duct 6 and air for atomizing the slurry is introduced via a duct 8, dry raw materials may be fed via a duct 7.
Manufacturing of cement in an apparatus of the aforementioned kind is done by the raw material slurry being fed to the GSD unit via the duct 6 and atomized in a nozzle in the GSD unit by means of compressed air. Hot exhaust gases from the kiln are also fed to the GSD unit so as to ensure that the temperature in the GSD unit is increased to a level near 150.degree. C. Subsequent to being dried in the GSD unit, the gas/material slurry passes into the separation cyclone 9 where the exhaust gases are separated from the dried raw material and passed on to a not shown filter for dedusting via a duct 10. The dried raw material is routed via a duct 12 to the calciner 3 in which it is momentarily heated to a level near 800.degree. C. Hot exhaust gases from the kiln are fed to the calciner which also receives fuel via two burners which are located in the lower part of the calciner. Subsequent to calcination, the raw material passes to the separation cyclone 5 from which the exhaust gases are diver
REFERENCES:
patent: 3839058 (1974-10-01), Sylvest
patent: 3923536 (1975-12-01), Kobayashi
patent: 3986886 (1976-10-01), Sylvest
patent: 4080218 (1978-03-01), Mori et al.
patent: 4226585 (1980-10-01), Deussner
patent: 4248641 (1981-02-01), Deussner
patent: 5012751 (1991-05-01), Kirlin
patent: 5173044 (1992-12-01), Neilsen
patent: 5437721 (1995-08-01), Kupper et al.
F.L. Smidth & Co. A/S
Marcantoni Paul
LandOfFree
Apparatus and method for producing clinker from a hydrous slurry does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method for producing clinker from a hydrous slurry, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for producing clinker from a hydrous slurry will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1800748