In the process of cement production, cement clinker, materials, slag can be used after grinding, however, the results show that the best grinding efficiency can be achieved only by different materials separately.
First, process introduction
1.Feeding system
Wet slag, cement clinker, gypsum and other mixed materials are transported to the storage yard by truck transport, and into the hopper by forklift, this product line is provided with 5 feed hopper, in order to meet the requirements of different products. The bottom of each hopper is provided with a quantitative feeding method, through the transfer station into the vertical mill, a vibration screen is arranged at the transfer station, the aim is to remove impurities from raw materials when producing slag, but when producing the cement, this vibrating screen requires short circuit. In order to prevent metal block from entering vertical mill, the conveyor belt is arranged on the separator and metal detector.
2. Grinding system
The material from the feed into the central millstone mill, motor driven by reducer rotating disc, under the action of centrifugal force to the disc edge and the grinding roller compacted by mobile, the crushed material overflow from the disc edge, at the same time from the nozzle ring (air ring) high efficiency separator of high speed upward hot air flow to the mill and one in the coarse powder separator after separation after the return to the disc, re grinding; fine powder with gas outflow mill, collected in the dust collecting system, which is product. Entering the warehouse storage through the conveying and lifting machine. No metal parts by hot air flow with the coarse particles and accidentally enter the sink from the wind ring, the scraper scraping, the outer loop bucket feed mill for regrinding.
3.Finished product storage
At mill end provided with two mixing machine and the external active admixture device, to meet the production requirements of concrete admixture. Qualified finished hoist, chute into the 3 x 26 meters of 15 seat plate stored in the library. The bottom is provided with a charging chute, finished by the bottom unloading equipment, bulk loading machine factory.
Second, production line design characteristics and Practice
1.Control of particle size of grinding material
2.Vertical mill feed inlet
Vertical mill grinding system is the core of the whole production line, in order to meet the requirements of a multi-purpose grinding, the mill feed to do a lot of technical improvements. The common vertical upper lateral mill inlet due to water content of raw materials caused by excessive clogging, the inlet to the central screw conveyor feeding. This production line set a total of two mill feed inlet, the upper lateral inlet retention, to ensure the smooth feeding of clinker. According to the production on site, the setting of the two materials can ensure that the material is smooth, there is no phenomenon of blanking.
3.Design of hot air system
In order to ensure the stability of the boiling furnace heating, effective regulation and reduce costs, set up a circulating air system, and in the hot blast stove outlet pipe is set with electric high temperature control valve and cold air valve. In order to boiling hot stove and circulating air, cold air can effectively mix. Practice shows that, in the boiling furnace outlet temperature of hot air under controlled conditions, as close as possible to the cold air valve, circulating air to adjust the temperature of the feed gas, to reduce energy consumption.
4.Selection of dust collector for finished bag
This project finished collecting selection of air box pulse bag dust collector, used in the design of acrylic waterproof and oil temperature for dust collector polyester needle felt filter material. The filter material has good air permeability, the instantaneous working temperature is 160 ℃, the normal working temperature is 140 ℃. Put into operation since the dust collecting effect is good, the emission concentration is less than or equal to 20mg/Nm3.
5.Production process control
The DCS control system is used to control and monitor the whole process of the grinding system, the finished product transportation storage and the boiling furnace combustion system. The system adopts the module structure, the program is operated, the modification is convenient, the transmission speed is fast, the interface is simple and intuitive, the operation is reliable, and the productivity is improved.
