Product Overview

The EHZT series activated carbon adsorption and steam desorption tower is an efficient, economical and practical system designed for the purification of industrial organic exhaust gas. It combines exhaust gas filtration, VOC adsorption, odor removal, steam desorption and solvent recovery in an integrated treatment process.

The system uses the strong adsorption capacity of activated carbon together with fan-generated airflow to capture organic vapor molecules from contaminated air. It provides effective adsorption performance for exhaust gases containing benzene compounds, alcohols, ketones, esters, gasoline vapors and other organic solvents.

The adsorption time is designed according to the type and concentration of pollutants, while the required adsorption area is determined according to the exhaust gas volume. Each system is therefore engineered according to the actual working conditions of the project.

Different production processes may generate exhaust gases with different temperatures, concentrations and contaminant characteristics. Oil mist, dust, liquid droplets and high-temperature gas may reduce activated carbon performance. For this reason, coolers, filters and other pretreatment sections can be installed at the system inlet to protect the adsorption bed and ensure efficient long-term operation.

Working Principle

The EHZT activated carbon adsorption and steam desorption tower is designed for low-concentration, high-air-volume exhaust gas and high-concentration intermittent emission applications.

Activated carbon contains a large number of micropores capable of adsorbing organic compounds. When low-concentration organic exhaust gas passes through the activated carbon bed, organic solvent molecules are captured and concentrated inside the pores. The purified gas is then discharged through the exhaust stack after meeting the applicable emission requirements.

The adsorption process is a physical concentration process. It does not immediately destroy the organic solvents. After the activated carbon has adsorbed a certain amount of organic compounds, it must undergo steam desorption and regeneration.

During regeneration, saturated steam is introduced from the bottom of the adsorption tower. The steam heats the activated carbon bed and removes the adsorbed organic solvents. The resulting steam and organic vapor mixture enters the condenser and is converted into liquid.

The condensed liquid then enters a separation tank. Recoverable organic solvents can be separated and reused. If solvent recovery is not required, the liquid can be sent to the wastewater treatment system for further processing.

After steam desorption, the activated carbon contains considerable heat and moisture. A drying fan supplies air to remove residual moisture and reduce the temperature of the carbon bed. Once drying and cooling are completed, the adsorption tower returns to the next adsorption cycle.

The system normally includes at least two activated carbon adsorption units. While one unit performs adsorption, the other can carry out desorption, regeneration, drying or cooling. The two units operate alternately to ensure continuous exhaust gas treatment.

Operating Cycle

Key Features

• High adsorption efficiency and large adsorption capacity
• Suitable for a wide range of organic exhaust gas applications
• Steam desorption provides safe and effective activated carbon regeneration
• Organic solvents can be condensed, separated and recovered for reuse
• Large specific surface area and good selective adsorption performance
• Activated carbon is widely available and relatively economical
• Compact structure with a small installation footprint
• Simple maintenance and relatively low operating costs
• Capable of treating mixed organic exhaust gases
• Automatic control system provides simple and safe operation
• Fully enclosed structure suitable for indoor or outdoor installation
• Alternating adsorption and desorption units support continuous operation

System Components

Heat Exchanger

The heat exchanger is an important part of the cooling and condensation process. In a shell-and-tube heat exchanger, one fluid flows inside the tubes, known as the tube side, while the other fluid flows outside the tubes inside the shell, known as the shell side.

The tube bundle wall acts as the heat transfer surface. Transverse baffles are usually installed inside the shell to prevent flow short-circuiting, increase fluid velocity and force the shell-side fluid to repeatedly flow across the tube bundle.

This structure increases turbulence and improves heat transfer efficiency. Common baffle designs include segmental and disc-type baffles, with segmental baffles being widely used in industrial systems.

Multiple tube passes can be created by installing partitions in the end covers. This forces the fluid to pass through different groups of tubes several times, increasing fluid velocity and improving heat exchange performance.

When oil-containing exhaust gas or water-mist-containing gas passes through the heat exchanger, its temperature is reduced to the designed level. Water vapor and oil mist are condensed into larger droplets, improving subsequent separation and helping reduce visible white vapor emissions.

Heat Exchanger Advantages

• Low risk of blockage
• Convenient inspection and cleaning
• Strong adaptability to different operating conditions
• Efficient cooling and condensation performance
• Suitable for oil mist and water vapor pretreatment

Applicable Industries

The EHZT series activated carbon adsorption and steam desorption tower is suitable for VOC purification and organic solvent recovery in the following industries:

• Electronic component manufacturing
• Battery production
• Acid pickling workshops
• Laboratory exhaust systems
• Metallurgical processing
• Chemical plants
• Pharmaceutical production
• Industrial coating and painting workshops
• Food processing and brewing
• Furniture manufacturing
• Printing and packaging
• Adhesive and laminating processes
• Organic solvent storage and transfer

The system is particularly suitable for spray-painting exhaust gas containing recoverable organic solvents.

Typical Treatable Organic Compounds

Automatic Control and Safety

The EHZT system can be equipped with PLC automatic control. The control program coordinates adsorption, valve switching, steam desorption, condensation, drying and cooling.

• Automatic switching between adsorption and desorption towers
• Temperature and pressure monitoring
• Fan interlock control
• Automatic steam valve control
• Emergency shutdown protection
• Process alarm and fault indication
• Fully enclosed operation for improved workplace safety

Round Cooling Tower

A round cooling tower can be integrated into the condensation and cooling system to circulate cooling water and remove heat from the condenser and heat exchanger.

Precautions Before Starting the Circulating Water Pump

1. The piping system must be completely filled with water before startup. All air inside the pipes should be discharged before continuous operation.
2. After the pump starts, the water level in the basin will gradually decrease. Refill water until the normal operating level is restored.
3. Adjust the circulating water flow to the specified value and confirm that the water distribution system operates correctly.

Precautions Before Starting the Cooling Tower Fan

1. Remove any objects blocking the cooling tower air inlet, air outlet or surrounding ventilation area.
2. After the fan starts, check the operating current and voltage and confirm that they match the motor nameplate specifications.
3. If the motor is overloaded, stop the equipment, identify the cause and correct the problem before restarting.

Why Choose ES Air EHZT Series?

• Customized process design according to exhaust gas volume and VOC concentration
• Integrated adsorption, desorption, condensation and solvent recovery
• Alternating adsorption towers support continuous treatment
• Steam regeneration reduces activated carbon replacement frequency
• Pretreatment sections protect the activated carbon bed
• Suitable for mixed VOC exhaust gas
• Automatic operation with flexible process configuration
• Compact structure and convenient maintenance

Frequently Asked Questions

What is an activated carbon adsorption and steam desorption tower?

It is an industrial VOC treatment system that uses activated carbon to capture organic compounds and saturated steam to remove the adsorbed solvents. The desorbed solvents can then be condensed and recovered.

What working conditions are suitable for the EHZT series?

The system is suitable for low-concentration, high-air-volume exhaust gas and high-concentration intermittent VOC emissions.

Can the system operate continuously?

Yes. The system normally includes at least two adsorption towers. One tower performs adsorption while the other performs desorption, regeneration, drying or cooling.

Can the organic solvents be recovered?

Yes. Desorbed organic vapors can be condensed into liquid and separated through a recovery tank or phase separator. Recoverable solvents may be reused after appropriate purification.

Why is exhaust gas pretreatment necessary?

Dust, oil mist, liquid droplets and high temperatures can reduce activated carbon adsorption performance. Pretreatment helps protect the adsorption bed and extend its service life.

Can ES Air customize the system?

Yes. ES Air can design the system according to exhaust gas volume, VOC composition, concentration, temperature, humidity, emission pattern, solvent recovery requirements and available installation space.

Customized VOC Adsorption and Solvent Recovery Solutions

ES Air provides activated carbon adsorption, steam desorption, condensation recovery and industrial VOC treatment systems for different manufacturing processes.

Contact ES Air for exhaust gas evaluation, process design, equipment selection and customized engineering solutions.

Brief: The ES Air EHZT Series Activated Carbon Adsorption and Steam Desorption Tower is designed for industrial VOC purification and organic solvent recovery. The system combines activated carbon adsorption, steam regeneration, condensation, phase separation and automatic control for coating, chemical, pharmaceutical, printing, furniture and other industrial applications.