Method for drying materials by utilizing superheated steam

Abstract

The invention discloses a method for drying materials by utilizing superheated steam, which is characterized in that the superheated steam is added into a sealed container in which materials to be dried are arranged, the superheated steam is used for evaporating the moisture in the materials to be dried to generate steam, and the superheated steam is cooled into low-temperature steam; the low-temperature steam enters a low-temperature steam system from the sealed container under the condition that the flow rate of the low-temperature steam is controlled; a mechanical pressurizing device is used by the low-temperature steam system for pressurizing the low-temperature steam to obtain the boosted steam; and the boosted steam is used for indirectly heating the steam in the sealed container, the boosted steam discharges the latent heat of vaporization to generate condensed water, and the steam in the sealed container receives the heat to become the superheated steam for continuously drying the materials to be dried. In the invention, the moisture of the materials to be dried is similar to the moisture of a multiple-effect evaporation system and is discharged in a form of the condensed water. The invention has the advantages of high drying efficiency, low energy consumption and simple processes, and has an industrial base of large-scale implementation.

Description

Technical field: [0001] The invention relates to a method for drying materials by using superheated steam, more precisely, it relates to a method for directly drying materials by using superheated steam so that the moisture in the materials to be dried is separated in the form of condensed water. Background technique: [0002] In the current drying methods, there are mainly two types of drying methods. The first type uses air or flue gas as the drying medium, and uses the heat carried by the drying medium to evaporate the moisture of the material to be dried. The water vapor formed by the evaporation of water is mixed with the drying medium. Since it is difficult to separate the two gases, the heat energy has to be Exit the drying system in the form of water vapor, which is the main source of high energy consumption. The second type is to use superheated steam to dry materials (including vacuum drying). The materials to be dried are placed in containers (including vacuum co...

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Problems solved by technology

The second type is to use superheated steam to dry materials (including vacuum drying). The materials to be dried are placed in containers (including vacuum containers), and heating devices can be installed inside and outside the container. The heat energy provided by the heating device evaporates the moisture of the materials to be dried into Water vapor, this kind of low-temperature water vapor, is further used to do work. Although there are various methods and devices for doing work, due to the lack of practicability of these current methods and devices, it is difficult to form large-scale industrial use of this type of drying method, and even The vacuum drying method that has been successfully used in industry is also because the production efficiency is very low (less heat transfer medium under vacuum conditions), and the thermal efficiency is lower, only about 20-25%. This method is only suitable for heat-sensitive materials (see "Inorganic Salt Industry Handbook, edited by Tianjin Research Institute of Chemical Industry, etc.)

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