Triple-effect Evaporator for Recovery of Waste Ni-Cd Battery

A multiple-effect evaporator is a combination of multiple sets of single-effect evaporators, the characteristic is that the exhaust steam from the previous effect is reused in the aftereffect as heating source. There are double-effect, triple-effect, four-effect and even more effects, which are selected according to the working conditions.

MAIN PRINCIPLE 

In the multiple-effect evaporator, the Effect I is heated by the live steam, and the exhaust steam from Effect I flows to Effect II and acts as the heating source, thus the live steam consumption is reduced. The total temperature difference between the heating temperature in Effect I and the boiling point in last effect, is distributed in each effect, the temperature difference between effects decreases as the amount of effect increases.

The water evaporated forms exhaust steam (called as secondary steam) is reused by multiple times, the live steam consumption is reduced, so as to achieve the purpose of energy saving.  

MAIN FEATURE

1. The multiple-effect evaporator is suitable in case there is sufficient and low-cost steam;

2. It is appropriate for concentration of solution which is of big elevation of boiling point (eg. Sodium hydroxide, calcium chloride and etc);

3. It is recommended if there are various wastewater being treated, which are big differences in physical property and need to be treated separately;

4. The process flow is adjustable based on actual condition, different evaporation process (eg. Forward flow, cocurrent flow, countercurrent flow and cross flow) can be adopted  accordingly.

Application Scope

       Multiple-effect evaporator is a widely used evaporation and concentration equipment applied in fermentation industry, starch/starch sugar industry, fruit juice and beverage industry, pharmaceutical industry, chemical industry and wastewater treatment.

System Configuration

        A multiple-effect evaporator is composed of heaters of each effects, separator (crystallizer) of each effects, condenser, thermal compression pump, vacuum pump, material circulating pumps, operation platform, instrumentation and control cabinet, and pipline and fittings.

Equipment Specification

The evaporation capacity ranges from 200kg/h to 500ton/h maximum, can be customized according to demands. And the evaporator type can be falling film type, rising film type, forced circulation type, external circulation type and etc. And the structure can be tubular type, plate type and scraper type for option.