Although low-temperature evaporation equipment and high-temperature evaporation equipment belong to wastewater concentration and separation equipment, their core differences stem from the essential differences in evaporation temperature and energy consumption modes. This difference further extends to multiple dimensions such as applicable scenarios, equipment design, and operating costs, directly determining the application boundaries and selection logic of the two types of equipment. Below is a detailed analysis from six core dimensions:

From the perspective of core operating principles and temperature control, the implementation paths of the two types of devices are completely different. The core of low-temperature evaporation equipment is to create a negative pressure environment through a vacuum pump, reduce the boiling point of water, and enable wastewater to vaporize and evaporate at a low temperature of 40-60 ℃ - for example, when the system vacuum degree is maintained at -0.09MPa, the boiling point of water can be reduced to around 45 ℃, and water separation can be completed without high-temperature heating. High temperature evaporation equipment relies on direct high-temperature heating and operates in atmospheric or slightly positive pressure environments. It raises the temperature of wastewater to 100-180 ℃ through heat sources such as steam and fuel (coal, natural gas), and uses high temperature to directly break the intermolecular forces of water molecules, achieving rapid vaporization. The key to the former lies in "negative pressure temperature control", while the key to the latter lies in "high temperature heating". This principle difference is the root cause of all the differences between the two types of equipment.

The difference between the two types of equipment is particularly significant in terms of energy consumption mode and operating costs. Low temperature evaporation equipment mainly relies on "electricity+heat pump" as its energy source, and has the ability to recover heat - the equipment releases condensation heat when condensing steam, which can be transported back to the heating stage through the heat pump system to achieve heat recycling and greatly reduce energy loss. The energy consumption cost for treating one ton of wastewater is usually only 0.2~0.5 yuan. However, high-temperature evaporation equipment relies on steam or fuel for heating, resulting in significant heat loss during the high-temperature heating process (such as boiler thermal efficiency of about 80%, pipeline heat dissipation loss of about 10%), and the inability to effectively recover condensation heat, leading to high operating costs. The cost of treating one ton of wastewater is generally between 1-3 yuan, and even higher in some high energy consumption scenarios. For small and medium-sized processing projects, the cost advantage of low-temperature equipment will directly affect the economic viability of the project.

The difference in applicable wastewater types is essentially due to the different tolerance of the two types of equipment to "heat sensitive substances". Low temperature evaporation equipment, due to its low operating temperature, can effectively prevent the decomposition or volatilization of thermosensitive components in wastewater, making it more suitable for treating high salt wastewater containing alcohol, organic acids, and easily oxidizable organic compounds (such as pharmaceutical wastewater and food processing wastewater). For example, when treating high salt wastewater containing ethanol, a low-temperature environment can prevent resource waste and air pollution caused by the high temperature volatilization of ethanol. High temperature evaporation equipment, due to its high temperature, can cause the decomposition of thermosensitive substances (such as high-temperature carbonization of organic compounds) or the production of volatile harmful gases (such as acidic gases and VOCs). Therefore, it is only suitable for high salt wastewater without thermosensitive components and with stable chemical properties (such as concentrated salt water in chemical parks and metallurgical wastewater). Even if such wastewater is treated at high temperatures, it will not produce additional secondary pollution or compositional changes.

The differences in equipment material and structural design are directly determined by operating temperature and pressure. Low temperature evaporation equipment operates at low temperatures and has negative pressure in the system, requiring low temperature resistance of materials. The mainstream materials used are 316L stainless steel (salt corrosion resistance) or titanium (high salt and high corrosion scenarios) to meet the requirements; Structurally, there is no need for complex high-temperature and pressure resistant designs. The core components are only the vacuum pump, heat pump unit, and evaporator, making the overall structure compact. High temperature evaporation equipment needs to withstand high temperatures above 100 ℃ and atmospheric/micro positive pressure, with extremely high requirements for material temperature and pressure resistance. Carbon steel (high temperature resistance and low cost) or Hastelloy alloy (high corrosion and high temperature scenarios) are usually selected; Structurally, it is necessary to install high-temperature and pressure resistant components such as steam boilers, high-temperature pipelines, and safety valves. At the same time, to reduce heat loss, thick insulation layers need to be added to the pipelines and equipment casings, resulting in larger equipment volumes and more complex structures.

The difference in evaporation efficiency and processing scale reflects the application scenario positioning of the two types of equipment. Low temperature evaporation equipment, due to its low temperature and slow vaporization rate of water molecules, has a relatively small processing capacity per unit, usually 0.5-5 tons/day, making it more suitable for small and medium-sized, decentralized wastewater treatment needs (such as point-to-point treatment in enterprise workshops and small industrial parks). High temperature evaporation equipment, with its advantage of high temperature, has a fast vaporization rate of water molecules. The processing capacity of a single device can reach 10-100 tons/day, or even larger, which can meet the large-scale and centralized wastewater treatment needs (such as centralized treatment stations in large chemical parks and concentrated brine treatment in municipal sewage plants). The former pursues "flexibility and low consumption", while the latter pursues "efficiency and large quantity", and the two correspond to processing needs of different scales, with almost no direct competitive relationship.

The differences in supporting facilities and site requirements affect the initial investment and site planning of the project. The supporting facilities for low-temperature evaporation equipment are extremely simple, only requiring the connection of power supply and wastewater pipeline network, without the need for additional construction of steam boilers, chimneys or soft water preparation systems (to avoid boiler scaling), occupying a small area, and can even be designed as mobile equipment, with strong adaptability to the site. High temperature evaporation equipment requires the construction of supporting facilities such as steam boilers (including fuel storage areas), flue gas treatment systems (treating boiler exhaust), and soft water preparation systems. The investment and land area of these supporting facilities even exceed that of the equipment itself, and the boilers are special equipment that require special approval procedures. The initial investment is large and the construction period is long, which is only suitable for large-scale projects with sufficient space and approval conditions.