1. The core reason for the absence of obvious odor is the closed vacuum design: The low-temperature evaporator operates entirely within a negative pressure closed system, ensuring that steam and volatile organic compounds (VOCs) generated by wastewater evaporation do not directly leak into the workshop environment. The steam is recovered as distilled water through a condensation system, and the tail gas consists only of a small amount of non-condensable gases, which are discharged through a closed pipeline.

Exhaust gas treatment system: Mainstream industrial models are equipped with exhaust gas treatment units such as condensation recovery + activated carbon adsorption / photo-catalytic oxidation / scrubber, which further capture residual odor molecules (such as hydrogen sulfide, ammonia, volatile organic acids, etc.) to ensure emissions meet standards.

Suppression of Volatilization under Low Temperature Conditions: Compared to normal-pressure high-temperature evaporation, a low-temperature operating environment ranging from 30 to 60℃ can significantly reduce the volatilization rate of volatile odor substances in wastewater, thereby reducing odor source emissions.

II. Common Causes of Odor Generation: Equipment Seal Failure: Aging of vacuum system seals, leakage at flange/pipeline connections, and damage to vacuum pump oil seals can lead to the leakage of non-condensable gases containing odors.

Failure of exhaust gas treatment unit: The activated carbon adsorption was saturated and not replaced in time, the concentration of the washing liquid was insufficient/not replaced regularly, and the photo-catalytic oxidation equipment malfunctioned, resulting in the odor molecules not being effectively treated.

Wastewater with special components: When treating wastewater containing high concentrations of sulfides, ammonia nitrogen, organic acids, and aromatic compounds (such as wastewater from pharmaceutical, chemical, electroplating, and food processing industries), if the pretreatment is insufficient, odor substances will enter the exhaust system along with the steam.

Improper operation and maintenance: Failure to clean the equipment promptly after shutdown, leading to fermentation of residual waste liquid inside the equipment; excessive feedstock quantity causing fluctuations in system vacuum degree and abnormal tail gas emissions.

III. Practical Solutions for Odor Elimination: Check the Sealing and Vacuum System: Regularly inspect the vacuum pump oil quality, sealing components, and flange connections, and promptly replace aging parts; monitor the vacuum level daily to ensure stable negative pressure in the system.

Enhance exhaust gas treatment: Replace activated carbon periodically based on adsorption saturation/operating duration; maintain the liquid level and chemical concentration of the scrubber, and regularly test exhaust gas emission indicators; for high-odor wastewater, add two-stage adsorption or photo-catalytic oxidation units.

Optimize wastewater pretreatment: For wastewater with high ammonia nitrogen and high sulfide content, pretreatment processes such as stripping, oxidation, and neutralization should be carried out first to reduce the concentration of odor substances before entering the evaporator.

Standardize operation and maintenance procedures: After shutdown, the pipeline and heat exchange surface must be rinsed with clean water, and residual waste liquid must be drained; avoid overload operation to prevent abnormal vacuum levels from causing odor leakage.