DD251196A1 - BRUEDENWAER USE FOR THE PRE-AND AFTER DRYING OF BROWN COAL - Google Patents

Abstract

The invention relates to a method for drying Schuettguetern, in particular koerniger brown coal, which according to the principle of convective heat and mass transfer in Schuett- and fluidized beds, as well as in Gutstroemen taking advantage of the Bruederwaerme anfaellt in another drying process and usually unused in the atmosphere escapes. The method is characterized in that a liquid heat carrier is heated by the brussels and delivered to a gaseous heat carrier at the point of use and some or all of the bruises and / or the brude condensate heat up a liquid heat carrier and this or the brude condensate itself has its heat Place the place of use to a gaseous heat carrier, which is then passed into a separate apparatus that works on the principle of convective heat and mass transfer in Schuett- or fluidized beds.

Description

Field of application of the invention

The invention relates to a process for the drying of bulk materials, in particular granular lignite, according to the principle of convective heat and mass transfer in debris or fluidized beds and material flows taking advantage of the vapor heat, which is obtained in another drying process and discharged usually unused into the atmosphere becomes.

Characteristic of the known technical solutions

According to the commercial patent "Method of Brüdenwärmenutzung for the drying of bulk materials" (WP 235 904), the gaseous heat carrier is heated by the vapors and then passed into a separate apparatus that works on the principle of convective heat and mass transfer in debris or fluidized beds. A disadvantage of this technical solution is that, with a greater removal of the heat for the drying of bulk solids, the heat transfer with a gaseous heat transfer medium is material-consuming and loss-rich.

Object of the invention

The object of the invention is the development of a method for drying bulk materials by utilizing the accumulated in another drying process and unused Brüdenwärme, so that at the same final moisture content of the dry material total thermal energy is saved. This reduces the specific steam requirement at a higher throughput or the absolute and specific steam requirement at the same throughput of the dry material.

Explanation of the essence of the invention

The invention has for its object to develop a method for waste heat utilization in the drying process, especially in tube dryers of the lignite industry. The vapor heat should be fed via a suitable heat transfer to another drying process in which the heat transfer according to the principle of convective heat and mass transfer in beds and streams gives off its heat.

According to the invention, the object of the Brüdenwärmenutzung is achieved in that a part or all of the vapors and / or the vapor condensate heat a liquid heat carrier and this or the vapor condensate itself emits its heat at the place of use of a gaseous heat transfer medium.

This is then fed to a separate drying process, which runs on the principle of convective heat and mass transfer. Advantageous compared to the Brüdenwärmegewinnung means gaseous heat transfer is that in liquid heat carriers the necessary apparatus size in the heat recovery and the cost of materials and losses in the heat transfer are low. This makes it easy to retrofit into existing systems.

It is possible, in certain applications, to heat the heat transfer medium beyond the temperature level achieved by the vapor.

embodiment

The vapor stream of a tube dryer in the briquette factory releases its heat content to a moving liquid. The thus heated liquid is discharged directly at the point of use in a heat exchanger to a gaseous heat transfer medium. This is then fed to an apparatus that works on the principle of convective heat and mass transfer and used there for drying. Optionally, the gas or liquid stream before the convection dryer can also be heated additionally.

Claims (2)

1. A method of Brüdenwärmenutzung for the drying of bulk materials, especially lignite, characterized in that the vapor condensate or a liquid heat carrier, which is heated by the vapor and / or by the vapor condensate, emits its heat at the point of use of a gaseous heat transfer medium which is then directed to a separate apparatus operating on the principle of convective heat and mass transfer in debris or fluidized beds. 2. The method according to item 1, characterized in that a necessary heating of the liquid or gaseous heat carrier over the temperature level achieved by the vapor out with other heat sources is possible.