Low-temperature evaporators are prone to various malfunctions during operation due to factors such as water quality, operational conditions, and equipment aging. Below are six common types of failures and their key symptoms to facilitate quick troubleshooting:

Scale / Clogging Failure  This is the most frequent fault, primarily caused by wastewater containing high levels of salt, calcium/magnesium ions, or organic matter. Symptoms include:  - White scale/hard scale buildup on heating tubes/heat exchange surfaces, leading to a sharp decline in heat transfer efficiency;  - Clogging of pipelines, nozzles, or vacuum pump inlets, resulting in "flow interruption," "sudden drop in vacuum level," or "abrupt reduction in evaporation capacity.".

Vacuum system failure affects low-temperature evaporation by disrupting the stable vacuum environment required to maintain a low boiling point. The consequences directly impair evaporation efficiency, manifesting as: abnormal vacuum gauge readings (below set values or significant fluctuations); elevated temperatures within the evaporator that fail to sustain low levels (e.g., evaporation intended at 40°C rising above 55°C); unusual noises or overheating of the vacuum pump; or a noticeably reduced vacuum pumping speed.

Refrigeration system failure: The refrigeration module is responsible for condensing vapor. After a malfunction, it may lead to "inability to liquefy vapor." Symptoms include: no condensation on the outer wall of the condenser or minimal condensation; frequent startup of the refrigeration compressor, overload shutdown, or abnormal noise during operation; no rise in the liquid level of the condensate tank, and exhaust gas carrying a large amount of water vapor.

Heating system failure  The heating module (such as electric heating or heat pump heating) serves as the "power source" for evaporation, and its malfunction leads to a significant decline in evaporation efficiency. Symptoms include:  - The heating tube not heating up or insufficient heating temperature (thermometer shows below the set heating temperature);  - Heating circuit tripping (overload protection triggered);  - Reduced heating capacity of the heat pump system, with slow temperature rise inside the evaporator.

Level control failure: Abnormalities in the liquid level sensor or control system can lead to "dry burning" or "liquid overflow." Symptoms include: excessively high liquid level in the evaporator, causing the solution to spill into the vacuum system; excessively low liquid level, exposing the heating tube to air and resulting in "dry burning" (accompanied by a burnt smell or overheating alarm); and the liquid level gauge displaying severe fluctuations that do not match the actual liquid level.

Mechanical component failures primarily involve moving parts such as pumps and valves. These failures manifest as: abnormal noise or excessive vibration in circulation pumps, or insufficient outlet pressure (leading to reduced wastewater circulation flow); sticking of solenoid valves and globe valves, preventing normal operation (e.g., feed valves failing to close tightly causing leaks, or discharge valves failing to open resulting in slurry accumulation); and stopping or abnormal rotation speed of mixers (if present), causing uneven heating of wastewater.