Heating – Processes of heating or heater operation – Including passing – treating or conveying gas into or through...
Patent
1985-10-30
1987-05-05
Yuen, Henry C.
Heating
Processes of heating or heater operation
Including passing, treating or conveying gas into or through...
432 96, 432 99, F27D 108, F27B 1500
Patent
active
046628410
DESCRIPTION:
BRIEF SUMMARY
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a national phase application corresponding to PCT/DE85/00082 filed Mar. 14, 1985 and based upon German application P 34 727.9 filed Mar. 16, 1984 under the International Convention.
FIELD OF THE INVENTION
The invention refers to a process for burning and sintering of lump materials, such as limestone, dolomite, clay pellets of the aluminum industry and the like in a shaft furnace heated by oil, gas or coal dust, wherein the material passes successively through a preheating area, a burning area and a cooling area and wherein at the top end of the cooling area, cooling air traversing this area from bottom to top is aspirated and heated combustion air is supplied to the burner.
BACKGROUND OF THE INVENTION
It is known from German open application 31 40 582 that the cooling air, brought up from the bottom to the cooling area of a shaft furnace for cooling the burned and sintered goods and which gets heated in this cooling process, can be aspirated in the upper part of the cooling area and supplied to the burner as combustion air. In the case of such a shaft furnace the heat consumption is noticeably lower, since the heat content of the cooling air is used for the combustion process.
Unfortunately the quality of the aspirated reheated cooling air is variable in its heat and oxygen content. This has proven to be a disadvantage since it leads to undesired oscillations of the temperature in the combustion area.
The object of this invention is to make possible the use of the heat content of the reheated aspirated cooling air to supply the burner with combustion air having a constant heat and oxygen level.
SUMMARY OF THE INVENTION
In accordance with the invention, this object is attained by passing the combustion air supplied to the burner through a recuperator fed with the reheated cooling air.
When the temperature of the aspirated cooling air is high, part of this cooling air can be directed through a bypass duct which bypasses the recuperator. If, on the contrary, the aspirated cooling air does not reach the temperature required for the heating of the combustion air, the aspirated cooling air is reheated before entering the recuperator.
The heat content of the cooling air remaining in the recuperator after the combustion air has been heated, can be used as heating- or combustion air, but is preferably used in a drier for drying the material to be processed by the shaft furnace.
The installation according to the invention is characterized by the presence of a recuperator supplied with cooling air aspirated from the shaft furnace through a closed-circuit pipe and reheating the combustion air it directs towards the burner. Preferably, a bypass duct directing part of the cooling air past the recuperator is provided; thereby, the presence of a cyclone between the closed-circuit pipe and the recuperator is necessary.
An air preheater can be provided for further heating of the cooling air supplied to the recuperator.
BRIEF DESCRIPTION OF THE DRAWING
The drawings consist of a single FIGURE. This FIGURE provides a schematic overview of the claimed process and apparatus. Gas streams are diagrammatically displayed by means of arrows and equipment represented symbollically.
Further features and advantages of the invention result from the following description, wherein the example of one embodiment is illustrated in detail by the schematical drawing consisting of a sole FIGURE.
SPECIFIC DESCRIPTION
The material to be burnt and sintered prepared in the form of wet pellets is supplied by a bucket conveyor over a sluiceway 1, free from infiltrated air, to the shaft drier 2. The pellets travel through the shaft of the drier and are directed at its lower end via a sluiceway 3 and a sieve 4 towards the bucket conveyor 5 which car ries them to the sluiceway 12 of the shaft furnace 6.
The spent cooling air V.sub.2 directed through a recuperator 7 of the shaft furnace V.sub.6, after the admixing of dry fresh air 6 by a ventilator 8 and the cooling thereof to th
REFERENCES:
patent: 3033545 (1962-05-01), Azbe
patent: 3142480 (1964-07-01), Azbe
patent: 3392969 (1968-07-01), Muller
patent: 3544090 (1970-12-01), Peeters
patent: 3761567 (1973-09-01), Parsons
patent: 3955915 (1976-05-01), Buchner
patent: 4015932 (1977-04-01), Zurawski
patent: 4403951 (1983-09-01), Beckenbach et al.
patent: 4473352 (1984-09-01), Sonoda et al.
Dubno Herbert
Ross Karl F.
Yuen Henry C.
LandOfFree
Method for burning and sintering limestone, dolomite and the lik does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for burning and sintering limestone, dolomite and the lik, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for burning and sintering limestone, dolomite and the lik will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2396778