Air classification grinder

——Sodium bicarbonate grinding in flue gas deacidification process

Hazardous waste treatment, steel plant coke oven, thermal power generation, municipal waste, sludge incineration, non-metallic ore burning, ceramic industry, glass manufacturing

With the increasingly strict requirements of environmental regulations, the dry deacidification principle of baking soda developed by Parman in combination with advanced processes in Europe and America has been increasingly applied. Dry adsorption using sodium bicarbonate as adsorbent to remove various pollutants contained in flue gas. Its purification effect can be compared with other known methods, such as spray adsorption with lime milk as adsorbent. Dry flue gas purification can not only be used in coal-fired power plants, hazardous waste treatment, municipal waste or alternative fuel incineration plants, but also widely used in industrial furnaces in industries such as glass, cement, and metallurgy. The use of dry flue gas purification can economically remove gases containing acidic substances, such as SO2, HCI, etc., and meet the national standard for flue gas emissions.

The flue gas contains a large amount of acidic gases. After extensive data and experiments, it has been found that only when sodium bicarbonate (baking soda, NaHCO3) is small enough to react with the acidic components in the flue gas with greater efficiency. It removes acidic pollutants from flue gas through chemical adsorption, and can also remove some inorganic and organic trace substances through physical adsorption. This process directly sprays sodium bicarbonate fine powder into high-temperature flue gas. Sodium bicarbonate decomposes at high temperatures to produce sodium carbonate Na2CO3, H2O, and CO2.

In general, the flue gas temperature is between 140 and 250 ° C. Due to the high activity of sodium bicarbonate adsorbents, a slight excess of sodium bicarbonate (with a stoichiometric factor between 1.1 and 1.3) is usually sufficient.

The particle requirements are related to the composition of the flue gas, and the required particle size for the removal of SO2 and HCl may vary. Due to transportation and storage reasons, sodium bicarbonate raw materials are usually coarse particles (with a d50 value of approximately 200 microns). To achieve high reaction activity, the adsorbent must have a large specific surface area. Therefore, before injecting into the flue gas pipeline, sodium bicarbonate must be ground to a certain fineness. For example, to remove SO2, the fineness of sodium bicarbonate must reach d90<20 µ m. And removing HCl only requires d90<35 µ m. If the system operation is correct, more than 95% of SO2 can be removed; The removal rate of HCl can even reach 99%. In order to maintain the required fineness of sodium bicarbonate in long-term operation, an air grinder is usually used for grinding, and the adsorbent is transported by gas transportation and directly introduced into the flue gas pipeline through multiple nozzles to ensure uniform dispersion in the pipeline. This equipment is designed to be simple and durable, and its investment and operating costs are lower compared to other flue gas purification methods.

The sodium bicarbonate grinding process will be the core process of this technology.

Product Introduction:

The CAM-V series internal classification grinding machine (vertical classification) is a micro powder production equipment with ultra-fine classification function, belonging to the same class of models as foreign ACM. This machine is mainly suitable for crushing materials with Mohs hardness below 3.5, and can obtain ultrafine powders of 5-150um. The large flow rate of cooling gas can be used for crushing thermosensitive materials.

Performance characteristics:

1. The built-in classifier of this machine replaces the traditional model's sieve to adjust the fineness.

2. By adjusting the speed of the grading impeller, the particle size of the product can be adjusted without stopping the machine.

3. The powerful crushing airflow during system crushing generates strong cooling function, and the temperature rise during crushing is low, making it particularly suitable for processing thermosensitive and fibrous materials, with uniform product particle size.

4. The bearings and transmission belts are made of imported components, which have a long service life.

5. Based on the characteristics of the materials, specialized designs will be made for crushing and grading components, upgrading from a universal crusher to a specialized crusher to further improve crushing efficiency.

6. Suitable for crushing materials with low to medium hardness (below Mohs 3.5), special materials need to be improved in terms of material and structure customization.

Component composition:

operational principle

Sodium bicarbonate is uniformly fed into the CAM air classification mill through a weight loss spiral feeding system, where it collides, rubs, and shears with the high-speed rotating grinding block and gear ring under various forces. After crushing, it enters the classification area with the airflow, and qualified materials enter the flue through the classification wheel for reaction. Coarse materials fall into the crushing area and continue to be crushed. The size of the particles can be adjusted by adjusting the speed of the classification wheel.

Process description:

Integrated with grinding and grading functions, it can flexibly obtain the required particle size;

Optimize structural design, reduce the temperature rise of the grinding machine;

Durable design, compact and sturdy structure; The hammer head and gear ring are made of special wear-resistant materials, requiring less maintenance;

Hydraulic cover design for grinding machine, easy to open for cleaning and maintenance;

Reasonable structure, can be compactly arranged with feeding devices, fans, etc;

Can integrate temperature, pressure, vibration and other sensors for real-time monitoring system;

Technical parameters: