What is a detailed desulfurization limestone mill?

As a large coal consumption country, China’s atmospheric environment is heavily polluted by sulfur-containing flue gas emitted by coal combustion. The flue gas desulfurization work of thermal power plants, the large coal-burning households, is very important. At present, the desulfurization technology with mature technology can be divided into three types: wet method, dry method and semi-dry method. The principle is simple to let the alkaline desulfurizer react with SO2 in the flue gas to avoid the direct discharge of acidic substances into the atmosphere.

1. Common desulfurization process in power plants

Wet desulfurization: common desulfurization agents: limestone, lime/slaked lime

Advantage

1. It has high desulfurization efficiency, reliable operation, and is suitable for a wide range of coal types.

2. The raw material limestone desulfurizer is rich in resources and low in price.

Disadvantage

1. The system occupies a large area, high energy consumption for operation, and high initial construction cost.

2. The pipeline is easy to block, scale and wear.

3. A large amount of gypsum and waste water are produced.

Dry desulfurization: common desulfurization agent: limestone

advantage

1. The process is simple, and there is no problem of sewage and acid treatment.

2. Low energy consumption.

3. The temperature of flue gas after purification is higher, which is conducive to the diffusion of chimney exhaust.

shortcoming

1. The desulfurization efficiency is low.

2. The equipment is huge, the investment is large, and the area is large.

3. High technical requirements for operation.

Semi-dry desulfurization: common desulfurization agent: lime/slaked lime

advantage

1. The process is simple.

2. The equipment basically has no corrosion, no wear, no scaling, and no waste water discharge.

3. It occupies less land, saves space, and has low investment in equipment.

shortcoming

1. Lime with high purity and activity needs to be used as desulfurizer.

2. The comprehensive utilization of desulfurization products is also subject to certain restrictions.

Power plant desulfurization technical indicators:

Limestone: Composition requirements: CaCo3 content > 90% Particle size requirements: 250 mesh 90% sieving rate (low sulfur content coal) 325 mesh 90% sieving rate (high sulfur content coal)

Lime: Composition requirements: CaO content > 85% Particle size requirements: 200 mesh 90% sieving rate

Slaked lime: composition requirements: Ca(OH)₂ content > 90% particle size requirements: 325 mesh 90% sieving rate

2. Production process of desulfurizer

Crushing: Large pieces of limestone or lime need to be crushed first, and the particle size of the abrasive should be within 2 cm.

Production process

Grinding: The crushed material is evenly sent into the mill, and crushed under the force of the grinding roller. The material with qualified fineness is sent to the classifier with the airflow and passes smoothly.

Production process

Collection: The qualified materials selected by sorting enter the pulse dust collector or cyclone collector to realize the separation of material and gas, and the collected materials are sent to the next process through the discharge valve. Most of the airflow participates in the next cycle, and the excess airflow is cleaned by pulse dust removal and then discharged to the atmosphere.

Production process

Conveying: The unloading valve under the cyclone/pulse collector can be connected to the bulk machine for direct loading and transportation to the destination, or sent to the finished product warehouse for storage through the conveying mechanism.