Technological process of cement clinker vertical grinding production line
Date：2019-06-28 09:35 Source：未知Views:
1. Crushing and pre-homogenization
2. Preparation of raw material
(1) Raw material ingredients: the raw materials are provided with limestone, sandstone, iron ore and fly ash four-seat material base (or other special auxiliary materials base), and the bottom of the warehouse bottom is respectively provided with a weighing feeder, and various materials are quantitatively given according to the ratio required by the production process. And the belt conveyor is fed into a vertical mill system for grinding.
(2) Raw material grinding: through the locking air feeding device, the material falls into the center of the grinding plate through the cutting slip, and under the action of centrifugal force, it is thrown to the edge of the grinding disk and rolled and ground by the grinding roller. The comminuted material spills from the edge of the grinding disk and is dried by the hot air flow from the nozzle high speed upward. According to the different air flow velocity, some materials are brought to the high efficiency powder separator by the air flow, and the coarse powder is returned to the grinding disk after separation. Re-grinding; The qualified fine powder is mixed with the dust collected by humidifying tower and electric dust collector after being ground out of the air flow, and sent to the raw material homogenization reservoir through the inclined slot and bucket hoist for homogenization and storage.
4. Preheating and pre-decomposition.
The preheating and partial decomposition of raw meal are completed by preheater instead of part of the function of rotary kiln, so as to shorten the length of return kiln, at the same time, the process of gas material heat transfer in the kiln is carried out in the stacking state, and moved to the internal suspension state of preheater, so that the raw meal can be fully mixed with the hot gas discharged from the kiln, and the contact area of gas material is increased, the heat transfer speed is fast, and the heat exchange efficiency is high, so as to improve the production efficiency of kiln system. The purpose of reducing the heat consumption of clinker firing.
(1)Preheater:the main function is to make full use of the waste heat discharged from the rotary kiln and the decomposition furnace to heat the raw material to preheat the raw material and decompose some carbonates. In order to maximize the heat exchange efficiency of gas-solid room and realize the high quality, high yield and low consumption of the whole calcination system, it is necessary to have three functions of uniform gas-solid dispersion, rapid heat exchange and efficient separation.
(2) pre-decomposition: the emergence of pre-decomposition technology is a technical leap in cement calcination process. It is to add calciner between preheater and rotary kiln, to set up fuel injection device between preheater and rotary kiln, so that the exothermic process of fuel combustion and the endothermic process of carbonate decomposition of raw meal can be carried out rapidly in suspension state or fluidization state in the calciner, and the decomposition rate of raw meal into kiln can be increased to more than 90%. The original carbonate decomposition task carried out in the rotary kiln is moved to the calciner; most of the fuel is added from the calciner, and a small part is added by the kiln head, which reduces the heat load of the calcined belt in the kiln and prolongs the service life of the lining. The fuel and the raw material are uniformly mixed, the combustion heat of the fuel is communicated to the material in time, and the combustion, the heat exchange and the carbonate decomposition process are optimized. Thus having a series of excellent properties and characteristics such as high quality, high efficiency, low consumption and the like.
5. firing of cement clinker
After the raw meal is preheated and predecomposed in the cyclone preheater, it enters the rotary kiln for clinker firing. Carbonate is further decomposed rapidly in rotary kiln and a series of solid state reactions take place to form AC3,AFC4,SC2 and other minerals in cement clinker. With the increase of material temperature near C01300, AC3,AFC4,SC2 and other minerals will become liquid phase, and SC2 dissolved in liquid phase will react with CaO to form a large amount of SC3 (clinker). After the clinker is burned, the temperature begins to decrease. Finally, the high temperature clinker unloaded from the rotary kiln is cooled by the cement clinker cooler to the set temperature of the storage. And meanwhile, the sensible heat of the high-temperature clinker is recycled, and the thermal efficiency and the clinker quality of the system are improved.
6. Cement batching station
Cement batching station is equipped with clinker, gypsum, auxiliary material storehouse, each warehouse bottom is equipped with weighing feeder, according to the set ratio to give all kinds of materials quantitatively. Another bulk clinker loading facility is provided on the storeroom side of the clinker storeroom for external use of clinker. After the material is discharged proportionately by the feeding metering equipment, it is sent to the ball mill by the belt conveyor for grinding.
7. Cement grinding
Cement grinding is the last working procedure of cement manufacturing, and is also the most power consuming process. The method mainly comprises the following steps of: grinding the cement clinker (and the gelling agent, the performance adjusting material and the like) to a proper particle size (expressed by the fineness, the specific surface area and the like), The cement finished product is collected by an air box pulse bag type dust collector and then is conveyed by an air conveying chute, and the bucket elevator is sent to a cement finished product library for storage.
8. Cement packaging
After the delivery cement is discharged from the base unloading device, it is sent to the cement packing workshop and the cement bulk bin by the adhesive tape conveyor, the bucket elevator and the air conveying chute. In which the cement package adopts an eight-mouth rotary packaging machine, and the packaged bagged cement is sent to a bagged cement finished product warehouse for storage through a bag discharging and conveying system, and can be directly loaded and shipped. The cement bulk storage room is provided with a cement truck bulk facility for bulk use by the vehicle.