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EPC projects’ management and operations.

What are the basic parameters that the roller press can adjust?

2019-11-07 16:52:25 | mill
Product introduction:https://www.lvssn.com/mill/Roller-Press.html

Jiangsu LVSSN company core cement epc


The roll press is like the roll crusher, but its function is different, there are essential differences.Roller mill in cement powder has occupied a dominant position, what are the basic parameters of roller mill can be adjusted?
 



1. Working principle of roller press




roller press
 



The roller press consists of two rollers (namely moving roller and fixed roller), frame, reducer, torque support, motor, pressure system and feeding device.When the two rollers run in opposite directions under the power, the material from the upper part is pulled into the gap between the two rollers. Then the hydraulic cylinder installed on the back side of the moving roller starts to pressurize, driving the piston forward and pushing the moving roller to put pressure on the material.With the two rollers continue to pull the material into the gap of the roller and compacted and crushed, into the cake unloading, the cake after the finished products into the mill or storage, unqualified products return to continue rolling, until the final complete grinding.
 



2. Parameters of roller press



 



2.1 pressure of roller press




The pressure of the roller press is a key parameter of work efficiency.The yield of ground powder is almost determined by pressure.When the pressure is 60MPa, the passing rate of 32 micron fine powder is about 20%. If the content of fine powder increases to 30%, the pressure should reach 100-300mpa.At the same time, the experiment shows that when the pressure is very high, the increase of fine powder production rate is not obvious, but the power consumption is doubled. At the same time, because of the pressure increase, the material cake is not easy to break, the power consumption of tube mill will also increase.The conclusion of the experiment on a small roller press is that when the passage rate of 45 microns is 36.1%, the required working pressure is 205MPa, from which it can be seen that the passage rate of 80 microns will be higher.Domestic data show that the average roll pressure in 120- 150MPa, 0.08 fine powder production rate can reach 50%.

Combined with the actual situation, the average roller pressure should be more than 60MPa, if it can reach more than 100MPa is the best, so not only the fine powder production rate is high, high work efficiency of the roller press, but also reduce the cycle load, transmission equipment energy consumption will be reduced, is conducive to reducing the system power consumption.

 



2.2 control of feed size




The feed particle size of the roller press, can be determined by 3.5% of the roller diameter, under the appropriate pressure, stable operation, should not be too large, the data shows that when the diameter of 7.0% of the roller diameter, the current fluctuation of the roller press will increase several times, not conducive to stable operation.
 



2.3 selection of roller seam




Roller gap is also one of the important parameters of roller press, generally 2.0% of roller diameter.The original roller gap is generally about 10mm. It needs to be reminded that, before setting the original roller gap, the radial runout of the roller should be tested radial, the most prominent position of the two rollers should be transferred to the horizontal position of the opposite direction, and then the limit block should be fixed so that the gap is about 10mm, and the two axes should be parallel.




roller press
 



2.4 installed power of roller press




When the average roll pressure is at 60MPa, the power consumption of tons of materials is 2.4kw, but the actual pressure at ordinary times will be about 1.5 standby. A large number of experimental data show that rolling a ton of clinker requires 3.5kwh, a ton of limestone requires 3.0kwh, and a ton of slag requires 6.0kwh, so the installed power should be greater than this value.
 



2.5 selection of roll seam displacement




Roller press roll gap to stabilize the best, but in actual operation, due to the change of particle size, the influence of oil compressibility, vibration, etc, is bound to change, but I did not allow unlimited expansion, roll gap must set a reasonable displacement, if the displacement is too large, will surpass the self-aligning bearing Angle, bearing damage, so must limit, generally offset control in 3 to 5 mm, but the best through the allowed Angle calculated bearing, both to ensure the safety of bearing, also ensure the extrusion effect.
 



2.6 roller linear speed




The linear velocity of roller is closely related to the production, but the experiment shows that the linear velocity is linearly related to the production when the linear velocity is 0.2-1.5 m/s.When the linear velocity is 1.5-1.8m /s, the relationship between output and velocity decreases, indicating that the ability of roller to bite the material is decreasing.Therefore, the linear speed of the roller press should be below 1.8m/s.
 



2.7 output of roller press




The output of the roller press is measured by the passing quantity, which is related to the speed of the roller, the volume and weight of the cake, the thickness of the cake and the width of the roller.namely

G = 3600 BVSP (t/h)

Where: t/h for table G, width meter for B roller, linear velocity meter/S for V roller, thickness meter for S cake, about 2.25% of the straight diameter of the roller., the bulk weight of p cake is about 2.4 tons/m3.

In fact, after the installation and use of the roller press, the structure parameters can not be changed, only the size of the pressure, the size of the roller gap offset, the size of the size of the material size and the number of recycling materials.Pressure is the most critical data, which directly affects the work efficiency, fine powder production rate;The difference of roller gap not only affects the bearing installation, but also affects the roller pressure effect.Granularity involves operational stability;The amount of circulation also involves the density of incoming materials, too much fine powder or granular material too much will cause the entry of excess air, not conducive to stability and so on.




The page source:https://www.lvssn.com/Product/What-are-the-basic-parameters-that-the-roller-press-can-adjust.html

The reasons and solutions of grate gap clogging in grate cooler

2019-11-07 16:49:55 | burning
Product introduction:https://www.cementepc.net/burning/Grate-cooler.html

Jiangsu LVSSN company core cement epc


Grate cooler is an important equipment in the rotary kiln system. On the one hand, it cools the hot clinker out of the kiln to a suitable temperature. During the cooling process, it displaces the heat energy in the clinker and contains it in the hot air.On the other hand, through the grate bed advance, the clinker will be transported to the appropriate location, broken into storage.Therefore, the role of grate cooler can be for cooling clinker, convenient transportation, convenient storage;Replacement of heat energy, effective saving of coal.

Grate for grate cooler is very critical, is the passage of the wind, the size of its section area is related to the wind resistance and through the amount, but this has been determined in the design and manufacturing, the use of units is to find a way to maintain this parameter, prevent the grate plug.The reasons and solutions of grate gap clogging in grate cooler



grate cooler



1. Reasons for grate blockage



 



1.1 improper material cushion of pu before kiln opening




For example, the cushion powder has more particles and less, the cushion clinker is moist, small particles and powder will be trapped in the grate, at this time the fan of the grate cooler cannot be opened, but the temperature rises with the temperature of the kiln, clinker condensation will occur, so when the fan is opened, in fact, part of the grate has been blocked.
 



1.2 wet bottom of grate bed




Some enterprises in order to reduce the temperature of the residual air, often in the grate cooler to add atomized water, once the wind temperature low atomized water, will cause wet bottom, sometimes even stop the water, the result of the grate is firmly paste.
 



1.3 the clinker with liquid phase enters the grate cooler




For example, due to improper ingredients, adjustment on the kiln did not follow up, viscous belt liquid clinker into the grate cooler, if the adjustment is improper at this time, not only cause a snowman, but also cause grate plug.In addition, improper operation of the burner causes pulverized coal to fall into the grate cooler for combustion, and the clinker becomes sticky and blocks the grate cooler.
 



1.4 improper operation




Mainly refers to the operation does not adapt to or do not follow the grate bed of the wind change, such as the material layer changed, the wind pressure did not increase, sometimes even shut down the press;For example, improper shutdown, improper shutdown sequence, belt material stop wind, and so on, easy to cause plug grate.



grate cooler



2. Solution to plug the grate



 



2.1 block prevention before starting up




Before starting up the system, it is generally necessary to lay the clinker cushion at the hot end of the grate bed to prevent the burning of the hot clinker and the damage of the grate plate by the impact of large clinker.In the early stage of kiln ignition, the grate bed does not operate and the fan does not open. If the clinker cushion is moist and pink, it is easy to plug the grate seam of the grate cooler. Therefore, the clinker cushion should choose dry granular clinker.
 



2.2 during maintenance, the grate shall be cleaned carefully




During maintenance must be based on the usual situation, to the grate carefully cleaned, one by one inspection, cleaning, if not clear, must be replaced, otherwise inevitably affect the cooling effect.
 



2.3 strictly control atomized water




If some enterprises set atomized water on the top of the grate bed of the grate cooler, the atomized water amount and atomization effect should be strictly controlled to ensure that atomized water droplets vaporize before falling on the clinker. Meanwhile, the operation must match with the system, otherwise the wet bottom may occur at any time, and water should be stopped before the shutdown.
 



2.4 timely adjustment and reasonable operation




No matter from the aspect of technology, or from the aspect of equipment, reasonable operation and timely adjustment are needed. However, there are too many contents involved, and only a few items can be highlighted. For example, if there are multiple layers of incoming materials, the grate speed should be accelerated, and the wind pressure and air volume should be adjusted.The material layer is thin to drop the grate speed, reduce the air volume and stop the machine.If the fan fails, it should be opened in time. If the shutdown time is long, it must stop the grate cooler or other corresponding measures.Otherwise it is easy to plug the grate.And so on.

For the cold machine, the grate is very important, if you encounter other reasons for congestion or have a better solution can leave a message with us.




The page source:https://www.cementepc.net/company/The-reasons-and-solutions-of-grate-gap-clogging-in-grate-cooler.html