DE813677C - Process for firing ceramic products with a high carbon content and ring or chamber ring furnace for this purpose - Google Patents

Description

For kilns for ceramic. Products are known types at which the combustion gases wholly or partially through a before the vent to the chimney Fan extracted and then via a collecting duct, if required with fresh air mixed, fed back into the fire. Also the use of the unmixed and flue gases mixed with fresh air to preheat the insert is known, likewise the possibility of switching off chambers.

However, these known types are only suitable for burning one Material that contains less or as much carbon than for the cooking firing temperature is required. For ceramic products with a higher carbon content, undesirably high temperatures in the fire zone cannot be prevented, since the supplied Mixture of extracted flue gases and fresh air upon entry into the fire zone either has too high a temperature or contains too much oxygen, so that the The firing temperature of the briquettes is exceeded and that results from the incineration the amount of heat generated by the carbon contained in the material is not dissipated can be.

Also known is a method according to which a mixture of Water vapor and carbon dioxide, if necessary with nitrogen and other indifferent ones Gases diluted, the .Regulation of the combustion process is used, but must in this case the mixture can be generated in special steam generators, generators or the like.

The method on which the present application is based looks against it before the flue gases extracted from the combustion chambers with the help of a fan to send via a collecting duct through a flue gas air heater to cool down and then to use again chilled.

The cooled flue gases are then with fresh air, which through a controllable flap F is fed, mixed fed back to the fire. Corresponding of the fresh air supplied, flue gases can also be regulated Outlet flap are removed.

Due to the low temperature of the mixture it is achieved that in spite of contact with the cooling moldings, the temperature of the mixture is present Entry into the fire zone remains low and, as a result, a slow glow of use in the fire zone is achieved. At the same time, the amount of mixture supplied can be dimensioned so that that results from the combustion of the contained in the material Carbon-generating heat is absorbed and dissipated.

There is also the possibility, in a known manner, of one or more Switch off chambers from the fire zone and use them by means of cooled smoke gases cool quickly.

Each of the connection channels shown in the drawing can be opened and be closed. However, these closures are for the sake of clarity omitted.

Claims (2)

PATENT CLAIMS: i. Process for firing ceramic products with a high carbon content with the aid of a flue gas-air mixture, characterized in that the flue gas-air mixture is passed through a cooler before being reintroduced into the furnace. 2. Ring furnace or chamber ring furnace to carry out the process according to claim i, characterized by a fan (V) in a pipeline system is interposed, by means of which smoke gases are extracted from the individual chambers, passed through a flue gas air heater (L) and then, if necessary, with Fresh air mixed, reintroduced into the combustion chambers. Referred publications: German patent specifications No. 212495, 468784 524070.