The structure and principle of the tubular multi-effect distilled water machine

The tubular multi-effect distilled water machine is a highly efficient and energy-saving pure water preparation equipment. Its core principle is to achieve the cascade utilization of heat energy through multi-effect evaporation series technology. The following is a detailed analysis of its working principle and key processes:

1. Equipment core structure:

‌1. Multiple-effect evaporator‌

It is usually composed of 4-6 vertical tube evaporators in series, each effect includes heating tubes, spraying device and vapor-liquid separator.

2. Preheating system

It includes a condenser and preheaters for each effect, which are used to gradually increase the temperature of the raw water.

‌3. Vapor-liquid separation device‌

Use spiral centrifugal separation or wire mesh demister to remove droplets and impurities in the steam.

‌4. Condensation system‌

The final steam and distilled water are cooled and collected here, and some models use waste heat to preheat the raw water.

2. Working Principle Process:

‌1. Warm-up phase‌

After the raw water (deionized water or purified water) is pressurized by the pump, it passes through the condenser and each effect preheater in turn to absorb the waste heat and raise the temperature to 97-130℃.

‌2. Evaporation and heat energy cycle‌

First-effect evaporation: High-temperature industrial steam heats the first-effect tube array, and the raw water forms a falling liquid film on the inner wall of the tube, which partially evaporates into pure steam after being heated.

‌Multiple-effect series connection‌: The pure steam generated in the first effect is used as the heat source for the secondary effect, driving the subsequent evaporators in sequence; the unevaporated concentrated water flows from effect to effect and evaporates repeatedly, forming a cascade utilization of thermal energy‌.

Final effect treatment: The final effect steam enters the condenser and is cooled into distilled water, and the non-condensable gas is discharged through the discharge valve.

‌3. Vapor-liquid separation‌

Each separation chamber removes impurities entrained in the steam through centrifugal force or wire mesh defoaming device to ensure the cleanliness of pure steam.

‌4. Condensation Collection‌

The pure steam from the last effect is combined with the condensed water from each effect and then cooled to the standard of water for injection (output after the conductivity is qualified after online detection).