1、 Low temperature operation, significantly lower energy consumption than traditional high-temperature evaporation

Traditional high-temperature evaporation methods, such as multi effect evaporation and MVR mechanical vapor recompression, require heating wastewater to above 100 ℃ (under normal pressure), resulting in extremely high energy consumption; The low-temperature evaporator relies on a vacuum environment (usually -0.085~-0.095MPa), which can lower the boiling point of wastewater to 35-55 ℃, significantly reducing heating requirements.

Energy consumption comparison: Taking the treatment of 1 ton of high salt wastewater (TDS ≥ 5%) as an example, the energy consumption of traditional MVR evaporators is about 25-40kW · h, while the energy consumption of low-temperature evaporators (combined with heat pump technology) is only 8-15kW · h, reducing energy consumption by 40% -60%. Long term operation can significantly reduce electricity expenses.

Adaptation scenario: Especially suitable for small and medium-sized water volume (daily processing capacity of 5-50 tons) or energy cost sensitive enterprises, without the need for large boilers or high-pressure steam systems, with lower installation and operation costs.

2、 Avoiding the problem of "high-temperature scaling and corrosion exacerbation" in high salt wastewater

Calcium, magnesium, silicon and other easily scaling ions in high salt wastewater will quickly precipitate and adhere to the surface of heat exchange tubes in high temperature environments (such as traditional evaporation at 80-120 ℃), forming hard scale; At the same time, high temperature will accelerate the corrosion of metal equipment by corrosive ions such as Cl ⁻ and F ⁻ (such as 316L stainless steel, which is prone to stress corrosion cracking in high temperature and high chlorine environments). The operating range of 35-55 ℃ for low-temperature evaporators can effectively alleviate these two major problems:

Slowing down scaling rate: Salt solubility is higher at low temperatures, and crystal precipitation is slower during concentration. The scaling cycle has been extended from 7-15 days for traditional evaporation to 30-60 days, reducing cleaning frequency and equipment loss.

Reduce corrosion risk: The electrochemical corrosion rate of metals in low-temperature environments significantly decreases (by about 50% for every 10 ℃ decrease in temperature), which can extend the service life of equipment (such as 316L stainless steel equipment, which has a service life extended from 3-5 years to 5-8 years), especially suitable for highly corrosive wastewater such as high chlorine and high fluorine.

3、 High recovery rate of condensate water, achieving water resource recycling

One of the core goals of high salt wastewater treatment is "reduction" and "resource reuse". The low-temperature evaporator can achieve a high proportion of condensed water recovery through efficient steam condensation and dehazing design

Recovery rate performance: Under normal operating conditions, the recovery rate of condensate water can reach 80%~95% (i.e. 1 ton of high salt wastewater can recover 0.8~0.95 tons of condensate water), and the quality of condensate water is excellent (usually salt content ≤ 100mg/L, COD ≤ 50mg/L, turbidity ≤ 5NTU), meeting the standards of "circulating cooling water replenishment" and "process water replenishment" in the "Industrial Water Quality for Urban Wastewater Reuse" (GB/T 19923-2005).

Value realization: The recycled condensate water can be directly reused in production workshops (such as electroplating rinsing, chemical ingredients), reducing the dependence of enterprises on municipal tap water or groundwater, especially suitable for water scarce areas or enterprises with high water bills, achieving "wastewater resource utilization" and reducing water costs.

4、 High concentration ratio, significantly reducing the amount of hazardous waste disposal

The "concentrated solution" (or crystalline salt) produced after the treatment of high salt wastewater is usually classified as hazardous waste (such as HW06, HW17, HW22, etc.), and the disposal cost is extremely high (market price is about 3000-8000 yuan/ton). Low temperature evaporators, with the advantage of stable salt solubility at low temperatures, can achieve higher concentration ratios:

Concentration effect: High salt wastewater (initial TDS 5%~15%) can be concentrated to a high concentration solution with TDS 30%~45% (some conditions can be directly concentrated to a crystalline state, producing solid salt), with a concentration factor of up to 8-10 times, which means a reduction of 80%~90% in hazardous waste.

Cost savings: Taking the daily treatment of 10 tons of high salt wastewater (initial TDS 10%) as an example, traditional processes produce about 3 tons/day of concentrated liquid, while low-temperature evaporators only produce 1-1.2 tons/day. The annual hazardous waste disposal cost can be saved by (3-1.2) × 365 × 5000=about 3.285 million yuan, with significant economic benefits.

5、 High safety, suitable for the treatment of flammable and volatile wastewater

Part of the high salt wastewater (such as coal chemical wastewater and pharmaceutical wastewater) contains flammable and volatile organic compounds (VOCs) such as methanol, ethanol, and benzene. Traditional high-temperature evaporation requires heating to above 100 ℃, which poses a risk of organic matter volatilization and even combustion and explosion; The low-temperature operation characteristics of low-temperature evaporators fundamentally reduce safety hazards:

Avoiding the volatilization of large amounts of VOCs: 35-55 ℃ is much lower than the flash point of most flammable organic compounds (such as methanol flash point of 12 ℃, but the volatilization rate at low temperatures is only 1/5-1/10 of that at high temperatures), reducing VOCs emissions and lowering the concentration of combustible gases in the workshop to avoid explosion risks.

No risk of high temperature and high pressure: The equipment operates under negative pressure (vacuum state), without high temperature and high pressure components, resulting in higher operational safety. There is no need to equip complex safety and explosion-proof systems (such as safety valves and explosion-proof walls), reducing safety investment.

6、 Small equipment footprint, high degree of automation, and convenient operation and maintenance

Compared to traditional multi effect evaporators (which require supporting boilers and circulating water systems, typically occupying 100-200 square meters), low-temperature evaporators (especially modular equipment) have the characteristics of "integration and miniaturization":

Land advantage: A single set of low-temperature evaporators (including pre-treatment, evaporation, condensation, and control systems) with a daily processing capacity of 5-20 tons only takes up 15-30 square meters and can be directly installed in the corners or outdoors of the workshop without the need for a separate factory building, saving land costs.

Convenient operation and maintenance: Equipped with a PLC fully automatic control system, it can achieve the full process of "water inlet heating evaporation condensation slag discharge" automatic operation, requiring only one operation and maintenance personnel to conduct daily inspections (checking liquid level, vacuum degree, water quality); And the equipment has few vulnerable parts (mainly vacuum pumps and circulation pumps), long maintenance cycles (vacuum pump oil is replaced every 3-6 months, heat exchange tubes are cleaned every 1-2 years), and reduces manual operation and maintenance costs.

Summary: The core value positioning of low-temperature evaporators

The advantage of low-temperature evaporators lies in balancing the four major demands of treatment efficiency, cost, safety, and environmental protection with "low temperature" as the core. It not only solves the pain points of high energy consumption, easy scaling, and high safety risks of traditional high-temperature evaporation, but also meets the core goals of "reduction, resource utilization, and standard discharge" of high salt wastewater. It is particularly suitable for high salt wastewater treatment scenarios with small and medium water volume, high corrosion, and high risk, and is one of the key equipment in the current industrial wastewater zero discharge system.