Jiangsu Pengfei successfully developed vertical mill

[Abstract] As main power consumption of grinding system is raw meal manufacturing, coal powder manufacturing and cement grinding, Jiangsu Pengfei Group successfully developed the latest pre-grinding equipment of CKP vertical mill.  

 

Jiangsu Pengfei Group successfully developed the latest pre-grinding equipment of CKP vertical mill based on the absorption the technology of CK & CKP mill of Japan & German, CKP mill could implement large output improvement under tiny power consumption.  Our country focused on supporting the technical innovation of energy-saving, power consumption decreasing and emission reduction of grinding system, the potential of energy-saving of grinding system is very large as there are about 5100 grinding enterprises this year.

 

In order to find the way to implement output improvement & energy-saving of mill, local workers of grinding system developed pre-grinding process with the principle of shortening inlet grain size, adding crusher & reducing mill, improving mill output and reducing power consumption via years of scientific experiment and productive practice. This pre-grinding process shortens inlet grain size to 3mm, move the work of first chamber of ball mill to the outside which will be implemented by crusher while the efficiency of crusher could be 25-40%.

 

CKP vertical mill cut, extrude, crush & grind the material rotating complying with the grinding table with the function of three rollers which rotate symmetrically, its special roller design and material layer grinding technology largely reduces the power consumption per unit and it will be widely used in material grinding process of building material, metallurgical and chemical industries, etc. Meanwhile it could be used together with current ball mill as circular pre-grinding, circular classifying pre-grinding and final grinding system. Power consumption of integrative grinding decreases 30-50%, output increases 50-100% which has implemented the target of energy-saving, emission reduction, high efficiency grinding & output and low power consumption and it will has higher economic & social benefits. CKP vertical mill is composed of motor, reducer, grinding table, roller, hydraulic device, lubricating device, etc. Material will enter into the center of grinding table via inlet chute, as grinding table rotates and produces centrifugal force, then the material will be thrown into grinding area and it will be extruded and grand via pressurized roller. Grand material will fall into lower cover of mill via outer ring of grinding table, then they will be scratched into discharge chute and then they will be discharged, the characters of this system process are:

 

1. Roller takes use of forced lubrication to supply the oil which could effectively prevent the bearing from powder and it uses air sealing with forced ventilation and reinforced sealing.

 

2. Liner of grinding table and roller surface utilizes high-chrome cast iron with long useful life （＞30000Hr） which is easy to change.

 

3. Reducer utilizes static pressure lubricating system and monitors the oil pressure and temperature of bush to guarantee the stability of operation.

 

4. Hydraulic oil station utilizes batch type and following work mode, sets advanced following monitoring parts to check the status of equipment operation continually which could improve the working condition of system and extend the useful life of parts.

 

5.  The efficiency of output improving and power consumption reduction is obvious. Utilizing this grinding process implements the new technology application of extruding and grinding which is better than the current roller press. The capacity of raw mill for cement grinding could increase 100%, the capacity of cement clinker production could increase 50%, power consumption could decrease 30-40% and it could be used together with ball mill as grinding system which could extend the adjust range of fineness of product and improve the pressive strength of cement.

 

Cement grinding utilizes pre-grinding process which is widely used in new-type dry process production line and it has become the trend of new factory construction or old factory innovation, while pre-grinding equipment mainly is roller press and vertical mill. Concerning the power utility ratio, roller press is a little higher than that of vertical mill, but concerning the operating stability and suitability of fed grain size, vertical mill is better than roller press. At present whatever roller press or CKP vertical mill is used for pre-grinding, it could improve the output and the effect of energy saving. While compared with vertical mill, the maintenance of roller press is harder, the wear-out period of roller surface is about 6000hours, after this, it should be pull down for repairing of welding. While operating ratio of CKP vertical mill is high, useful life of roller surface could be over 30000hours, so the maintenance work is less. Factors which could affect the grinding efficiency are many including graduation of grinder, mill ventilation, clinker temperature and grinding process, etc., meanwhile closed circuit ball mill process with high efficient separator should be prior to be used, as closed circuit mill is good for adjusting & controlling the fineness & temperature of product, while the grinding efficiency is 10-20% higher than that of open circuit and the finer finished product is, the more obvious the advantage is.

 

Different grinding system has different advantage and shortage, when enterprises choose the grinding system for updating current mill, they should choose the proper solution according to their own equipment, raw material, management and investment condition, etc.

                                                                                  

                                        Jiangsu Pengfei Group Co., Ltd