DE573417C - Process for the operation of drying plants - Google Patents

Description

Process for the operation of drying systems Those drying processes, where the raw material to be dried is in a stream of hot air, hot combustion gases, superheated vapor or in mixtures thereof entered and in this stream up is held in suspension for complete drying, run at such a speed, that a uniform degree of drying is only possible if the steady state is precisely maintained the drying system with regard to the supply of raw materials and heat. is. Accordingly was previously able to, when commissioning and shutting down such systems, Desired degree of dryness cannot be maintained.

Are drying systems of the type mentioned in the peculiar to them, heat-economically particularly advantageous way at high temperatures and with operated with a high throughput, so must according to the above when switching on and off the plant as well as with occasional interruption of the raw material supply large amounts of under or. overdried end product accumulate. In the event of unintentional interruptions in the In addition, there is a risk of damage to the device when the dry material is fed in, because the heat coming from the heating source into the drying device is in such Cases are not used to evaporate water from the dry material, rather fully against the walls of the device or against its expensive lining device.

The difficulties mentioned can according to the invention with particular Advantage with the high initial temperatures that occur with fire gas drying, be avoided that as long as the supply of the dry material in the under Fire standing dry days, be it with or without intent, in whole or in part is locked, the material to be absorbed by the dry material during normal operation of the system Heat is destroyed by introducing water behind the heating source to such an extent that that the 'introduced water evaporates completely and with the thereby cooled Removes heating gases as steam from the system. In doing so, the water to be evaporated expediently distributed over the entire cross section of the heating gas flow, what. can be done for example by spraying using nozzles.

According to the invention, water-containing substances can be used in the drying process, if desired Raw materials are proceeded in such a way that after turning on the furnace before the entry of Dry material the steady state of the system in relation to the evaporation of the Raw material moisture, required amount of heat and thermal tension under spraying of water is set beforehand. After reaching the desired steady state wind from water to dry material, in order to shut down the plant the other way round from dry material switched to water. In both cases it is particularly advisable to use the one brought in Measure the amount of water.

The specified method offers in its application to drying flammable raw materials, especially from Brennstoffezi, the simultaneous advantage an immediate and effective protection against the niennals in such cases - Completely avoidable fire hazard.

Claims (1)

PATENT CLAIM: Method of operation. of drying systems, in which the raw material to be dried is introduced into a stream of hot gaseous or vaporous desiccants and is kept in suspension by the same until the drying is complete, characterized in that the temperature of the heating gases passing through the drying pile, if dry material is not in the drying room is present, wind is reduced by introducing water into the heating gas flow.