Keywords: lime production line, lime rotary kiln, lime production equipment, pulverized coal preparation, pulverized coal ball mill
1. Page description
Cathay (Wusu) Biomaterials Co., Ltd. is located in Wusu, Xinjiang. In November 2016, it ordered an active calcium production line with a daily output of 400 tons from Henan Zhengzhou Mining Machinery Co., Ltd., and is equipped with coal powder preparation and calcium oxide grinding equipment. The entire production line was installed and debugged in October 2017 and went into production smoothly.
Signing date: 2016-11-30
Processing materials: limestone, raw coal
Processing capacity: active calcium oxide 400t/d, pulverized coal 200 t/d
Equipment configuration: lime rotary kiln, rotary cooler, coal mill, bag filter, lime storage bin, lime ball mill, other supporting equipment and electrical control system
2. Project Overview
Cathay (Wusu) Biomaterials Company is mainly engaged in research and development, production of biotechnology products, research and development of biotechnology, etc. In November 2016, due to business needs, a full set of production equipment with 400 t/d activated calcium oxide, 200 t/d pulverized coal preparation and 40 t/h calcium oxide grinding mill, was ordered from Henan Zhengzhou Mining Machinery Co., Ltd.. The design, equipment manufacturing, installation, and commissioning of the production line were all undertaken by Henan ZK Corp, and it was officially put into production in October 2017.
The final product of the production line is calcium oxide powder, which integrates active calcium calcination, coal powder preparation, calcium oxide cooling, storage, grinding and waste gas treatment. The unit energy consumption is less than 1150kCal/kg, and the temperature of the product out of the cooler is ambient temperature +60 ℃, the exhaust gas emission concentration is less than or equal to 30 mg/Nm3, it has the characteristics of high output, stable operation, low rate of burnout and overburn, environmental protection and energy saving.
3. Solution
This project is a limestone production line turnkey project. It mainly provides and implements limestone calcination, coal powder preparation, active calcium cooling storage, active calcium grinding, and exhaust gas purification treatment during the production process of active calcium oxide:
1) Limestone is calcined in a professional lime rotary kiln. During production, the limestone in the silo enters the kiln from the end of the kiln, and moves to the kiln head as the kiln barrel rotates. During the movement, it contacts the high-temperature gas coming from the kiln head and exchanges heat, and completes the preheating and decomposition process and is calcined. Active calcium oxide. The structure of the production line of this scheme is simple, the materials are heated evenly, the rate of product burnout and overburn is low, and the quality is stable.
2) Coal powder preparation system. The pulverized coal preparation system is set in the kiln head, which is an air-swept ball mill system. The raw coal uses part of the hot air from the cooler to dry the raw coal. The finished product is taken out of the mill by the hot air and collected into the pulverized coal bin by a bag filter for supply to the kiln head. Multi-channel burners are used. The program has a compact process flow, short pulverized coal transportation distance, saves land area, and recycles heat energy after calcium oxide cooling to save energy.
3) Activated calcium oxide is cooled and stored. The activated calcium oxide product enters the single-tube cooler after leaving the kiln for cooling. It is cooled from 900°C out of the kiln to ambient temperature plus 60°C. The cooling efficiency is high. Hot air enters the kiln, enters the mill for auxiliary combustion and raw coal drying. The activated calcium oxide from the cooler is transported into the silo into the bucket elevator.
4) Activated calcium oxide is ground to prepare calcium oxide powder and stored in the warehouse. The scheme is to add a ball mill between the two storage bins, and the block-shaped active calcium oxide is discharged from the bin and directly enters the ball mill for grinding. After the grinding, the calcium oxide powder enters the elevator and is transported into the bin for storage. The process is simple and applicable. Compared with the ordinary grinding system, it saves a lot of conveying and powder selection equipment and saves investment.
5) Treatment of kiln exhaust gas. The exhaust gas from the kiln is first purified by the cyclone dust collector, and then it is filtered by the bag filter for secondary filtration. The clean air is discharged into the atmosphere through the dust collecting centrifugal fan through the chimney. After being filtered by a bag filter, the dust content in the gas is less than 30mg/Nm3, which meets environmental protection requirements.
