Lime shaft kiln: DCS control system engineering for desulfurization and denitrification equipment

1、 Basic process and principle of mixed firing lime kiln:

Mixed burning lime shaft kiln is also called lime shaft kiln. The burning principle is to mix solid fuel (coke or anthracite) with qualified limestone raw materials evenly, lift the materials to the kiln top with lifting equipment, and evenly distribute the materials into the kiln through the rotary distributor on the kiln top. The mixture is heated and calcined by fuel combustion, and the kiln body is divided into three zones: pre heating zone, calcination zone, and cooling zone. Under the action of its own gravity, the mixture passes through the pre heating zone, calcination zone, and cooling zone to calcine into qualified finished lime. In the calcination zone, the coke or anthracite in the preheated mixture and the secondary air of the cooling lime from the kiln bottom burn to generate heat, so that the temperature of the calcination zone can reach 1100~1250 ℃ evenly, and then drop to the cooling zone to cool and complete the lime calcination. The finished lime is discharged from the kiln into the finished ash silo by the ash unloading device in a sealed state.

2、 Functional structure division of vertical kiln:

The structure of the lime vertical kiln is divided into eight parts: kiln body, raw material and fuel proportioning system, feeding and distribution system, ash unloading system, air supply system, temperature control system, material level detection system, environmental protection system, and automation system.

3、 Technical parameters:

1. Kiln volume: total volume, effective volume, total volume refers to the total space inside the kiln barrel, and effective volume refers to the actual volume of the space section for removing fabric, air supply, and ash discharge. The volume of the lime kiln is designed according to the required output, usually with a design volume of: 100; 200； 300； 400； 500； 600； 800, etc.

2. Utilization coefficient: refers to the production capacity of the kiln (24-hour output per unit effective volume). The utilization coefficient of the lime kiln is 0.6-0.75.

3. Operating reference cost: Lime kiln consumption: Limestone: 1.75t/t. ash. Coal: 120-150Kg/t. ash.

4. Environmental indicators: dust removal efficiency of 99%, smoke concentration ≤ 30mg, desulfurization efficiency greater than 80%, and SO2 concentration at the outlet of the desulfurization tower less than 200mg.

4、 Gas fired lime shaft kilns are classified into natural gas, blast furnace gas, coke oven gas, converter gas, and gas producer gas according to different gas types.

Zhengzhou Zhongwei Environmental Protection Equipment Co., Ltd. is a "general contracting" engineering manufacturer for lime shaft kiln burners, industrial kilns, automation control systems, and desulfurization and denitrification equipment. The types of gas burners designed for lime shaft kilns include natural gas burners, coke oven gas burners, blast furnace gas burners, converter gas burners, and yellow phosphorus tail gas burners. Design and integrate an automated control cabinet for the vertical kiln to achieve fully automatic control of burner combustion and production operations. Design, manufacture, and be responsible for the construction of desulfurization and denitrification equipment in response to increasingly urgent environmental protection tasks. Supporting online monitoring devices, coordinating with the Environmental Protection Bureau's technology, and assisting in environmental acceptance work. For more information, please feel free to call (WeChat synchronization): 15713691937.

Zhongwei Environmental Protection Group Co., Ltd.: Zhengzhou Zhongwei Environmental Protection Equipment Co., Ltd. and Zhengzhou Deste Automation Equipment Co., Ltd. undertake the "general contracting" project of large-scale lime shaft kilns, lime shaft kiln burners, shaft kiln control cabinets, desulfurization and denitrification equipment, and online monitoring devices at home and abroad, and provide and implement one-stop solutions for "coal to gas" environmental protection kiln solutions.

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