Cement production line flow
Date：2019-06-14 13:42 Source：未知Views:
Nissan 1000 tons cement production line solution
1. design parameters:
2. process flow:
Fragmentation and pre-homogenization
(1) Crushing: During the cement production process, most of the raw materials are broken, such as limestone, clay, iron ore and coal. Limestone is a raw material for producing large amount of cement. After mining, the particle size is larger and the hardness is higher. Therefore, limestone is a raw material for producing large amount of cement. After mining, the particle size is larger and the hardness is higher. The crushing process is more economical than the grinding process. Conveniently, as much as possible, the bulk material is broken into small, uniform particle size to reduce the load of the grinding equipment and increase the output of the machine. After the material is crushed, the separation of materials of different particle sizes during transportation and storage can be reduced, and the raw materials with uniform composition can be obtained, and the accuracy of the ingredients can be improved.
(2) Pre-homogenization of raw materials: Pre-homogenization of raw materials means that when the materials are stacked, the incoming raw materials are continuously stacked in a certain manner into as many parallel layers, upper and lower overlaps and layers of the same thickness. When taking the material, in the direction perpendicular to the layer of the material, all the layers are cut as much as possible, and cut in order, until the end is taken, that is, "tiling straight". The raw material storage yard has the functions of storage and homogenization.
Raw meal preparation
(1) Raw material ingredients: The raw material ingredients are provided with four parts of limestone, sandstone, iron ore and fly ash (or other special auxiliary materials). The bottom of the library is equipped with weighing feeders, which are matched according to the production process requirements. It is given more quantitatively than various materials. It is fed by a belt conveyor into a vertical grinding system for grinding.
(2) Raw material grinding: The material is dropped into the center of the grinding disc by the wind-feeding device through the wind-feeding device, and is pressed by the centrifugal force to the edge of the grinding disc to be rubbed by the grinding roller. The crushed material is from the grinding disc. The edge overflows and is dried by the hot air flow from the nozzle at a high speed. According to the different air flow speed, part of the material is taken by the air flow to the high-efficiency classifier, and the coarse powder is separated and returned to the grinding disc for re-grinding; The fine powder is mixed with the dust collected by the humidification tower and the electric precipitator after being sent out by the airflow, and sent to the raw material homogenization storage tank for homogenization and storage through the chute and the bucket elevator.
Raw material homogenization
When the raw meal powder is discharged downward, it is stirred by air and gravity, and a “funnel effect” is generated. The multi-layered material surface is cut as much as possible and thoroughly mixed. Different fluidizing air is used to cause different sizes of fluidization expansion in the parallel material surface of the reservoir. Some areas are unloaded and some areas are fluidized, so that the inner surface of the reservoir is inclined and radially mixed and homogenized. In the cement production process, the stable raw material composition is the premise of stabilizing the clinker burning thermal system, and the raw material homogenization system plays a role in stabilizing the raw material composition.
preheating and pre-decomposition
The preheating and partial decomposition of the raw material are completed by the preheater, instead of the partial function of the rotary kiln, the length of the return kiln is shortened, and the gas heat exchange process in the kiln is carried out in a stacked state, and moved to the preheater in a suspended state. Under the process, the raw material can be fully mixed with the hot gas discharged from the kiln, the contact area of the gas material is increased, the heat transfer speed is fast, and the heat exchange efficiency is high, thereby improving the production efficiency of the kiln system and reducing the heat consumption of the clinker. purpose.
(1) Preheater: The main function is to make full use of the residual heat of the exhaust gas discharged from the rotary kiln and the decomposition furnace to heat the raw material, so that the raw material is preheated and some carbonate is decomposed. In order to greatly improve the heat exchange efficiency between gas and solid, to achieve high quality, high yield and low consumption of the entire calcination system, it is necessary to have three functions of uniform gas-solid dispersion, rapid heat transfer and high-efficiency separation.
(2) Pre-decomposition: The emergence of pre-decomposition technology is a technological leap in the cement calcination process. It is a decomposing furnace added between the preheater and the rotary kiln, and a flue gas is used to raise the flue by the kiln tail, and a fuel injection device is provided to make the exothermic process of burning the fuel and the endothermic carbonate decomposition process. The furnace is rapidly carried out in a suspended state or a fluidized state, so that the decomposition rate of the raw material into the kiln is increased to 90% or more. The carbonate decomposition task originally carried out in the rotary kiln is moved to the decomposition furnace; most of the fuel is added from the decomposition furnace, and a small part is added by the kiln head, which reduces the heat load of the calcination zone in the kiln and extends the lining. The material life is beneficial to the large-scale production; due to the uniform mixing of the fuel and the raw material, the fuel combustion heat is transferred to the material in time, and the combustion, heat exchange and carbonate decomposition processes are optimized. Therefore, it has a series of excellent performances and features such as high quality, high efficiency and low consumption.
Burning of cement clinker
After the raw material is preheated and pre-decomposed in the cyclone preheater, it enters the rotary kiln for firing of the clinker. In the rotary kiln, the carbonate is further rapidly decomposed and a series of solid phase reactions occur to form minerals such as AC3, AFC4 and SC2 in the cement clinker. As the temperature of the material increases near C01300, the minerals such as AC3, AFC4, and SC2 become liquid, and SC2 and CaO dissolved in the liquid phase react to form a large amount of SC3 (clinker). After the clinker is fired, the temperature begins to decrease. After that, the high temperature clinker discharged from the rotary kiln is cooled by the cement clinker cooler to the set temperature of the storage for storage, and the sensible heat of the high temperature clinker is recovered, thereby improving the thermal efficiency of the system and the quality of the clinker.
Cement batching station
The cement batching station is provided with clinker, gypsum and auxiliary material warehouses, and each of the stocks is provided with a weighing feeder, and various materials are quantitatively given according to the set ratio. The clinker batching library is also provided with clinker bulk facilities for clinker use. After the materials are discharged by the feeding and metering equipment in proportion, they are sent to the ball mill by the belt conveyor for grinding.
Cement grinding is a post-process of cement manufacturing and a process that consumes a lot of electricity. The main material is that the cement clinker (and gelling agent, performance adjusting material, etc.) is ground to a suitable particle size (expressed by fineness, specific surface area, etc.), and the grinding material is sent to the high efficiency by the bucket elevator. The powder machine is sorted, the coarse powder is ground and the grinding is continued. The finished cement product is collected by the air box pulse bag type dust collector and then sent by the air conveying chute and the bucket elevator to the cement product storage.
After the unloading cement is discharged from the bottom discharge device, it is sent to the cement packaging workshop and the cement bulk bin by the belt conveyor, the bucket elevator and the air conveying chute. The cement packaging adopts the eight-mouth rotary packaging machine, and the packaged bagged cement is sent into the bagged cement finished product warehouse through the unloading bag conveying system, and can also be directly loaded and shipped. There are cement vehicle bulk facilities under the cement bulk warehouse for bulk use in automobiles.
Note: The material is ultimately subject to the material conditions provided by the user.
Large production capacity, high degree of automation, high product quality, low energy consumption, low emissions of harmful substances, and large amount of industrial waste.