In recent years, the concept of environmental protection has been deeply rooted in the hearts of the people, air pollution control has attracted attention from all walks of life, and waste gas treatment has become a topic of concern in various industries. This article will introduce the process flow, working principle and application of activated carbon adsorption tower, as follows:

2. Process description

??The organic waste gas from the workshop is collected by the suction hood, and under the action of the exhaust fan, it is transported into the dry filter through the pipeline, and then enters the activated carbon adsorption device. The organic pollutants are absorbed by the activated carbon, and the purified gas is discharged after being pressurized by the fan.

??After the activated carbon is saturated with adsorption, please recycle it after regeneration by a professional manufacturer.

??3. The adsorption principle of activated carbon

??A. The adsorption phenomenon is a phenomenon that occurs at the interface of two different phases. The adsorption process is the diffusion process at the interface, and the adsorption occurs on the solid surface, which is caused by the residual attraction on the solid surface.

Adsorption can be divided into physical adsorption and chemical adsorption; physical adsorption, also known as van der Waals adsorption, is caused by the electrostatic force between the adsorbent and adsorbate molecules or van der Waals gravitation. When the molecular gravitational force between the solid and the gas is greater than that of the gas Under the gravitational force between molecules, even if the gas pressure is lower than the operating temperature and the saturated vapor pressure, the gas molecules will condense on the solid surface, and physical adsorption is an endothermic process.

??Chemical adsorption, also known as active adsorption, is due to the chemical reaction between the surface of the adsorbent and the adsorbate molecules. It involves the destruction and recombination of chemical bonds in the molecules. Therefore, the adsorption heat of the chemical adsorption process is larger than that of the physical adsorption process.

??In the adsorption process, there is no strict boundary between physical adsorption and chemical adsorption. The same substance is often chemically adsorbed at lower temperatures. Activated carbon fiber adsorption is mainly physical adsorption, but due to the presence of surfactants, it also has a certain chemical adsorption effect.

??B. The characteristics of activated carbon adsorption of exhaust gas:

??(1). The adsorption of aromatic compounds is better than the adsorption of non-aromatic compounds.

??(2) The physics of hydrocarbons with branch bonds is better than the adsorption of straight-chain hydrocarbons.

??(3). The adsorption of substances containing inorganic groups in organic substances is always lower than the adsorption of substances without inorganic groups.

??(4). The adsorption of compounds with large molecular weight and high boiling point is always higher than the adsorption of compounds with small molecular weight and low boiling point.

??(5), the higher the concentration of adsorbate, the higher the adsorption capacity.

??(6), the larger the internal surface area of the adsorbent. The higher the adsorption capacity.

??Activated carbon fiber

The adsorption method using a new type of adsorbent-activated carbon fiber (ACF) as the adsorbent is a new type of organic waste gas recovery method developed in recent years. It is considered to be the most effective new method for recycling and purifying organic waste gas. Great attention of the majority of researchers and related companies.

??Compared with traditional activated carbon, activated carbon fiber has the following excellent characteristics:

??1) Large specific surface area, high effective adsorption capacity;

??2) Fast adsorption and desorption, low energy consumption and easy regeneration;

??3) High strength and long life;

??4) Various shapes, convenient for engineering applications;

??5) Can adsorb low-concentration gas;

??6) Strong adsorption selectivity.

??Activated carbon fiber organic waste gas recovery device

??Take the typical three-box adsorption device in the activated carbon fiber organic waste gas recovery device as an example to analyze its equipment composition, process flow and technical characteristics.

??Equipment composition

The adsorption equipment consists of an induced draft fan, a surface cooler, a filter, an adsorber, a layered tank, etc. The operation of the entire system is controlled by a PLC program, and the adsorber is automatically switched to alternately perform the operation of the adsorption, desorption and drying process. .

??Process flow

The volatile organic gas passes through a certain pre-treatment device, and then further removes impurities in the exhaust gas through a filter to ensure that these impurities do not occupy the pores of the activated carbon fiber and affect the adsorption efficiency and service life of the activated carbon fiber; the filtered exhaust gas is introduced by the fan Adsorption equipment.

The activated carbon fiber that has adsorbed a certain amount of organic solvent is desorbed with saturated water vapor. After the desorption is completed, the filtered outside air is sent to the adsorber to be dried by a fan, so that the activated carbon fiber bed is cooled and the residual steam is removed to make the activated carbon fiber Maintain a high adsorption efficiency. The dried adsorber enters the next working program cycle for adsorption.

The desorbed mixed steam containing organic matter enters the condenser for one-stage condensation. The condensate is cooled by a plate condenser. The condensed organic matter and condensed water enter the stratification tank. After gravity stratification, the upper organic matter automatically overflows to The storage tank is then sent to the adsorption recovery equipment by the transfer pump; the condensate in the lower layer is discharged into the wastewater treatment system.

??Technical features

??(1) Reasonable structure

??The adsorption core is a cage structure, which has the characteristics of small amount of activated carbon fiber and large air volume, which can greatly reduce the cost of organic waste gas treatment.

??(2) High adsorption rate

??Due to the specific surface area of activated carbon fiber, the adsorption rate can be as high as 95%. The patented technology can achieve multi-stage adsorption, and can achieve extremely high adsorption rate. It is currently an adsorption device that can meet the stringent environmental protection emission requirements in the world.

??(3) Low operating energy consumption and low cost

??Because of the desorption of activated carbon fiber and low energy consumption for regeneration, coupled with the low airflow resistance of the activated carbon fiber winding core and low fan power, the air and power consumption of the activated carbon fiber organic waste gas purification and recovery device during operation are relatively low.

??(4) Fully automatic control, unattended operation

??Using German Siemens programmable controller central control, integrated solenoid valve, German Festo cylinder to perform actions, high reliability. According to the design of the simulation panel display of the process flow, the operating status can be clear at a glance, and the design has fault detection and indication functions. Strong reliability, simple operation and easy maintenance.

??(5) Safe and reliable, suitable for explosive dangerous places

??Use explosion-proof fan and explosion-proof pump. The control cabinet and pneumatic cabinet adopt positive pressure explosion-proof technology, the external signal is connected through the safety barrier, and the system is grounded to ensure the safety of the device.