Abstract: An apparatus is disclosed for the conveyance and/or treatment of material-laden hot gases in a furnace for the calcination and sintering of lime, magnesite, dolomite or the like. The apparatus is utilized as a ventilator or ventilator mill in the furnace and is cooled by means of a cooling liquid circulating in a closed cooling circuit. Channels are provided in the ventilating apparatus for the liquid coolant and particularly such channels are provided in portions of the apparatus such as blades which are subject to the greatest heat stresses.

Abstract: A furnace is disclosed for the heat treatment of mainly lumpy to fine grained material. The furnace is either a shaft furnace or a rotary furnace for the calcination or sintering of limestone, dolomite or magnesite. The calcination material passes through a preheating zone, a calcination zone and a cooling zone. The calcination zone has a gas feed and gas withdrawal device. A calcination device is provided in the calcination zone to which is connected a gas conveying device for the production of a hot gas circulation. The hot gas circulation device is situated between the gas withdrawal device and the calcination device and is provided as a conveying blower subjected to a cooling liquid.

Abstract: A mechanism and method for preheating a coarse fraction and a more fine limestone fraction in a shaft preheater including a first central vertical inlet for receiving the coarse fraction which forms a descending core in a vertical preheating chamber, and a second vertical inlet receiving the finer fraction annularly around the core, directing a first upper gas feed radially into the fractions with the gas first penetrating the outer finer fraction and then the inner fraction, and directing a second heating gas flow at a lower level into the core to bring the core up to the temperature of the outer layer, with the gases being received from a rotary kiln, and mixing the fractions and directing them to the rotary kiln from the lower end of the preheating chamber.

Abstract: A method and apparatus is disclosed for the cooling of a lime shaft furnace for the calcining of limestone and which is operable with a combustible fuel. In shaft chambers of the shaft furnace, a hollow beam is provided to convey combustible fuel into the shaft chamber. Associated with the hollow beam is a cooling unit for cooling walls of the beam. A closed circuit cooling liquid system connects with the cooling unit so as to maintain a flow of a cooling liquid through the cooling unit. The cooling liquid has a boiling point of greater than 100.degree. C. This cooling liquid is continuously recooled by a heat exchanger.

Abstract: A device for treating granular or lumpy material by passing a gaseous medium therethrough characterized by a chamber having a material discharge device at the lower end and a material supply device comprising a pair of coaxially arranged supply channels at the upper end. The chamber has either a gas inlet or a plurality of burners to provide a gas flow through a portion of the material in the chamber and the material being added through the supply channels which are each connected to separate gas discharge conduits so that the material being added to the chamber is subjected to a uniform treatment by the gaseous medium.

Abstract: In vertical continuous furnace calcining of lime, dolomite, magnesite, or the like, part of the air which is introduced at the lower end of the furnace chamber is drawn off in the area of the cooling zone within the chamber and is then reintroduced in encompassing relation into the material column in the firing zone within the furnace chamber and which is located immediately above the cooling zone, the remainder of the air flowing up through the column of material being treated in the chamber. Cleaning of the withdrawn cooling air and addition of fresh air are provided for.

Abstract: A calcining method and apparatus are provided wherein material to be treated is fed into the top of the furnace and the finished material discharges from the bottom of the furnace and cooling and combustion air enters under forced draft through the bottom of the furnace and flows upwardly through the column of material. A part of the fuel supply is delivered to the region between an upper preheating zone in the furnace and a subjacent combustion or firing zone and the balance of fuel required for firing is introduced into the combustion zone about its periphery. Provision is also made for bypassing part of the cooling air from a lower cooling zone to the combustion zone, with intermediate cleaning of the bypassed air.