Preheating device

Abstract

The invention discloses a preheating device which can preheat the solution to the evaporating temperature or the temperature close to the evaporating temperature and utilize all the heat of steam. The preheating device comprises a barrel, a solution inlet arranged on the upper part of the barrel and a steam inlet arranged on the lower part of the barrel, wherein a solution outlet is arranged at the lower end of the barrel; a transition chamber connected with the solution inlet is arranged in the barrel; an inner barrel with hollow middle part is arranged in the transition chamber; a membrane distributor is arranged below the inner barrel; the barrel is also provided with a steam pipeline with one end connected with the steam inlet; and the steam pipeline is arranged below the membrane distributor. The preheating device has the following advantages: the steam is directly contacted with the solution and is blended in the solution, so that all the heat of the steam enters into the solution, thus heating the solution to the evaporating temperature or the temperature close to the evaporating temperature, providing good conditions for evaporation of the follow-up solution and being incapable of wasting the heat of the steam.

Description

technical field [0001] The invention relates to a preheating device for preheating a solution before the solution evaporates. Background technique [0002] Falling film evaporators are widely used in papermaking, chemical industry and other fields. In order to improve the evaporation efficiency of the falling film evaporator, a preheating device is usually used to preheat the solution before the solution enters the falling film evaporator, so that the temperature of the solution is as close as possible to the evaporation temperature of the solution before entering the evaporator, thereby improving the falling film evaporation. Evaporation efficiency of the device. Commonly used preheating devices generally use indirect preheating. Steam transfers heat to the solution through heat transfer tubes or plates, and the steam condenses into water to increase the temperature of the solution. However, due to the characteristics of the heat transfer method , that is, limited by the ...

AI Technical Summary

Problems solved by technology

Commonly used preheating devices generally use indirect preheating. Steam transfers heat to the solution through heat transfer tubes or plates, and the steam condenses into water to increase the temperature of the solution. However, due to the characteristics of the heat transfer method , that is, limited by the heat transfer temperature difference, part of the heat in the steam is absorbed by the heat transfer tube or plate, so the solution temperature cannot be preheated to the evaporation temperature of the solution, and the heat of the steam cannot be fully utilized, resulting in a waste of energy

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