Low temperature evaporator is an important part of the entire series of industrial wastewater treatment technology products.

The V-HP series vacuum heat pump evaporation system uniquely adopts compression heat pump technology, combined with suitable vacuum operation range, making it widely adaptable to the evaporation and concentration treatment of various industrial wastewater, and significantly reducing the energy consumption of treatment. This not only makes the concentration and reduction of various wastewater more reasonable technically, but more importantly, makes the application users economically willing to accept it.

The V-HP series vacuum heat pump evaporation system has a host energy efficiency ratio of over 9 under standard operating conditions, far exceeding that of multi effect evaporators (with energy efficiency ratios of 0.9, 1.7, 2.4, 3.0 for first effect, second effect, third effect, and fourth effect evaporators, respectively) and expanded concentration evaporators (with energy efficiency ratios of 4.2). More importantly, due to its adoption of a different technical organization than before, the operating temperature throughout the entire process is below 45 ℃, making it very suitable for applications in industrial wastewater treatment plants with the recovery of heat sensitive substances. At the same time, because the optimized heat pump system in the system has sufficient adaptability to a wide range of operating conditions, it has the ability to adapt to the threshold of boiling point increase commonly encountered in the evaporation and concentration process of wastewater, and can still maintain its high energy efficiency ratio. (Example for NaOH); 25% solution, its host energy efficiency ratio can still reach 6.5)

The main application industries of V-HP series vacuum heat pump evaporation system are:

★ Electrochemical industry:
Purification and recovery of wastewater
Purification and recovery of ion exchange device effluent
Purification and recovery of membrane device effluent
Purification and recovery of precious metals and nickel/chromium plating solutions

★ Petrochemical:
Concentration of emulsified oils and fats
Solvent recovery
Ethylene glycol recovery
Separation of organic compounds in water

★ Food industry:
Purification and recovery of wastewater
Collection of vegetable oil
Collection of whey and protein

★ Steel industry:
Purification and recycling of wastewater

★ Chemical Pharmaceutical:
Purification and recovery of wastewater
Purification and recovery of solvents

★ Textile printing and dyeing:
Reduction of silk wastewater and recovery of light alkali

Advantages of V-HP series vacuum heat pump evaporation system:
The V-HP system can make the goal of "zero emissions" more feasible
● Compact structure, small footprint, and no special requirements for construction sites.
. Low energy consumption, no need for steam supply. During operation, there is no odor spreading.
● Fully automatic operation, 24-hour operation. Minimize the amount of wastewater being sent out for treatment. Greatly enhance the image of corporate social responsibility.

V-HP series vacuum heat pump evaporation system:
★ The V-HP system uses scroll compressors and screw compressors, as well as environmentally friendly 410A refrigerant, and adopts strict processes to ensure the airtightness of the high-pressure operating refrigerant. ★ The V-HP system creatively combines with the wastewater circulation and distribution system, using a magnetic sealed pump to consume very little electrical energy, greatly improving the heat transfer efficiency of the heating coil, completely avoiding the adverse factor of boiling point increase caused by liquid column pressure, and overall improving the energy efficiency ratio of the entire system. The V-HP extraction method solves the impact of non condensable gases on the efficiency of cooling coils, while greatly reducing the impact of uncondensed steam extraction on the thermal load of the vacuum pump, thereby minimizing the operation requirements of the auxiliary maintenance system, significantly reducing energy demand and dependence, and lowering the capacity and usage time of the vacuum pump.
★ The V-HP system integrates and optimizes the system logic operation control, greatly simplifying the working requirements of the system and components, making it unnecessary to omit devices such as inlet pumps, outlet pumps, and vacuum detection in some situations. The evaporation concentration ratio of the V-HP system can be adjusted according to user needs, corresponding to wastewater without boiling point rise or material crystallization. In principle, the discharge of residual liquid can be minimized as much as possible through multiple cycles.

The V-HP vacuum heat pump evaporation system consists of five main subsystems: the refrigeration heat pump compressor system, the sewage evaporation condensation concentration system, the vacuum holding system, the intermediate circulation cooling system, and the automatic control operation system.

The joint working process of refrigeration heat pump compressor system and sewage evaporation condensation concentration system.

For sewage concentration, it is necessary to have a heating source to vaporize the water, separating the moisture in the sewage from the wastewater. Then, a lower temperature cooling source is needed to condense the vaporized water vapor into condensate water that does not contain pollution sources, either for qualified discharge or qualified reuse.

The composition of the cold and heat sources in this system is achieved through a compressor to obtain high pressure and high temperature. The working fluid gas is cooled into a liquid through a condenser, and the heat is transferred to the sewage, causing it to vaporize. The condensed working fluid is depressurized by an electronic expansion valve and absorbs the heat of water vapor generated by the vaporization of sewage in the evaporator. The working fluid (410A) becomes a low-pressure gas, which is then sucked in by the compressor and compressed, and works in a cyclic manner.

The water vapor generated by sewage absorbs heat in the working medium (410A) while releasing heat, condenses into clean condensate in the evaporator, and is discharged through the collection tank and water tank.

As the process continues, the water in the sewage is constantly vaporized and condensed, and the concentration of the sewage continues to increase. Until the target concentration is reached, it is discharged by the concentrated solution pump. For different types of wastewater, the remaining high concentration wastewater is subjected to crystallization separation, direct heating, drying, incineration, and other advanced treatments.

★ Automatic control system (omitted)

★ Vacuum Maintenance System:

The V-HP vacuum heat pump evaporation system is specially designed to operate in a vacuum environment. On the one hand, it vaporizes water at 100 ℃ or above (depending on the concentration and pollutant content of the wastewater) under normal pressure, making it controllable to operate within the range of about 40-50 ℃. This not only reduces system heat loss and improves efficiency, but also greatly improves the production and condensation efficiency of water vapor in the vacuum environment, which significantly reduces the demand for heat transfer surface of the equipment, reduces equipment cost and volume. At the same time, the lower working temperature prevents many reusable materials such as dyes, essential oils, and proteins in concentrated wastewater from high-temperature denaturation.

The vacuum maintenance system of this system adopts a two-stage water ring vacuum pump to maintain the system at around -95 to -97Kpa. During the operation of the system, due to inevitable leaks, as well as the air and other non condensable gases carried by the sewage to be treated during the addition process, the vacuum degree of the system will be continuously destroyed, affecting the system efficiency. Therefore, the system is designed to automatically detect and discriminate, and start the vacuum pump to work, usually for 1-2 minutes every half hour.

★ Intermediate circulation cooling system:

The V-HP vacuum heat pump evaporation system innovatively incorporates an intermediate circulation cooling system, which automatically adjusts the system to work stably according to different seasons. Through a simple system composition, it effectively eliminates the entropy increase heat of the system while obtaining the production of evaporated condensate water. In theory, there is always a situation where the input power entropy of a refrigeration heat pump unit increases and becomes heat. To maintain system balance, this part of heat must be removed. The V-HP system has found a good working point in the process design of removing unbalanced heat in the system, and compared with similar systems in the international and domestic markets, it has been determined to improve the energy efficiency ratio.

Operating parameters of the compressor under different operating conditions:

Selection parameters:

The main energy-saving principle of the V-HP series vacuum heat pump evaporation system is that, in addition to system heat dissipation, cooling loss, and thermodynamic entropy increase loss during operation, the heat used to evaporate wastewater and the heat generated by condensing evaporated water vapor is continuously recycled through the heat pump system. The higher the utilization and repetition rate, the higher the energy efficiency ratio. Secondly, the system should operate as close as possible to the environmental conditions, so that its comprehensive heat dissipation and cooling losses are lower, and its irreversible losses are also smaller. In a broad sense, its damage to physical properties is also lower. Therefore, a vacuum based heat pump system is adopted. Thirdly, for the operation control of the internal cold and hot ends of the system, minimizing the energy level difference as much as possible is the pursuit point to reduce the internal thermodynamic entropy increase. To improve the energy efficiency of the entire system, there is a long way to go, and it is necessary to effectively develop products that are adaptable to the field. It is confident that this is not a big problem both in theory and industrial technology capabilities. However, in the initial stage of such application fields, there are no relevant enterprises that recognize this huge application field, which is also the stage faced by the vacuum steam direct heat pump that we are developing and researching.

★ Technical and Economic Case:
1. A certain automobile tire cord production enterprise generates about 80 tons of drawing lubrication waste liquid every day. The waste liquid contains pollution sources such as oil, soap solution, and metal dust. The cost of handing over the waste liquid to the designated environmental protection sewage treatment center is 2500-3000 yuan/ton. When the production is at full capacity, the treatment fee reaches 250000 yuan/day. After a total investment of 8 million yuan (including civil engineering) was made to build an evaporation and concentration system with a daily processing capacity of 80 tons, the concentration reduction was less than 6 tons of sewage delivered to the designated environmental protection sewage treatment center every day, and the emissions were reduced by 90% to 95%. At that time, the energy efficiency ratio of the system operation did not exceed 4.0, and the daily operating direct cost was 20000 yuan, which not only effectively solved environmental problems but also had significant economic benefits.
2、 A certain textile printing and dyeing enterprise used triple effect concentrated silk wastewater (NaOH) for light alkali silk dyeing in the past, with a daily processing capacity of 90 tons. The concentration was reduced from 5% to 25%, and the concentrated solution was used for recycling. The daily steam consumption was 45 tons and the electricity was 400 kWh, with an energy cost of 10000 RMB. If we switch to a vacuum heat pump evaporation and concentration system, the daily energy cost will be reduced to 7000 RMB. (Note: The vacuum heat pump evaporation and concentration system is basically an all electric system, so it has more advantages if used in rich electric industrial areas, especially in the situation of continuous control of boiler equipment. It has obvious advantages in terms of environmental protection, economy, and convenient operation.)