Application of Roots blower in cement plant

Roots blower is one of the key equipment for supplying and using air and conveying powdery materials in the cement production line of mechanized shaft kiln and new dry rotary kiln. The quality of the Roots blower directly affects the output and quality of the clinker. In Hangtian cement plant of China United Cement Corporation, they use MTRF350 roots blower for the air supply of mechanized shaft kiln. MJR250D roots blowers are used to transport coal for kiln head and calciner of 3000t/d new dry process production line. Since the equipment started work, the roots blowers have had stable performance and good operation, which provides a guarantee for normal production.

Introduction to the principle and structure of Roots blower

Roots blower is a positive displacement blower, and the delivered air volume is proportional to the rotary speed. MTRF350 roots blower is of 2 impeller type. It has the characteristics of reasonable structure, strong universality, convenient maintenance, long service life, and good energy-saving effect. MJSR250D roots blower is of three lobes type. The three-blade impeller is sucked and vented three times by two impellers every time it rotates.

Compared with the two lobes type, the gas pulsation is less, the load change is less, and the mechanical strength is higher. Therefore, it has low noise and low vibration. There are two three-lobe impellers on two parallel shafts. An appropriate small gap is always maintained between the impellers and the inner hole surface of the oval casing and each impeller. As the impellers rotate at a uniform speed in opposite directions to each other, they can transmit a certain amount of gas surrounded by the box and impeller from the suction side to the discharge side. The synchronous gear will maintain the correct phase of each impeller without touching each other. Therefore, it can rotate at high speed without internal lubrication. Moreover, the utility model has the advantages of simple structure, stable operation, and stable performance.

Operation of Roots blower in Hangtian Cement Plant

The blower model of the No. 2 mechanical shaft kiln of the Hangtian cement plant is MTRF350. The air volume is 250m/min with a 185KW motor. There has been no equipment failure during its operation. The service team carried out A comprehensive overhaul regularly every year. After 10 years of normal operation, the roots blower operation sound was abnormal and the vibration was large, which affected the normal production of the shaft kiln. During maintenance, the technician found that the two shafts of the roots blower bent and deformed, causing the impellers to collide during rotation.

The technician eliminated the problem after grinding the impeller with a grinding wheel. However, this maintenance expanded the clearance between the impeller and the casing to 0.8mm. Although it can maintain normal operation, there are some deficiencies in the air supply, which brings difficulties to the normal calcination of the kiln. Hangtian Cement Plant purchased A Roots blower of the same model in time while maintaining production. It has been working in good conditions for the past 5 years. No exceptions occurred.

The air volume of the MJSR250D roots blower is 78.1m ³/Min @ pressure 0.05Mpa, with motor power 90kw. There are two sets in total, which are installed in the coal mill system of the 3000t/D production line. They Convey pulverized coal to kiln head and calciner respectively. Since its operation, there has never been any abnormal situation, which ensures the calcination performance of the rotary kiln.

Experience of Cement Plant Roots Blower Operation

Roots blower has the characteristics of simple structure, stable performance, and easy management and maintenance. However, the safe operation and service life of the blower ultimately depends on the normal use of the equipment and standard maintenance. Patrol inspection of equipment is very important. In case of any abnormality or hidden trouble, deal with it in time to ensure the safe, reliable, and stable operation of the roots blower.

(1) Roots blower Start

Start Roots blower under no-load condition. Before startup, open all the air inlet and exhaust valves. After normal startup, gradually adjust the valves to make the air volume reach the required value. It is not allowed to adjust to the rated air volume at one time.

(2) Shutdown

Roots blower shall not be shut down suddenly under full load operation. Gradually reduce the air volume before shutdown to avoid damaging the blower.

(3) Daily Maintenance

During normal operation, the post personnel shall conduct patrol inspections regularly every shift. The key point is to check whether the bolts at each part are loose, whether there is oil leakage, and whether the bearing temperature at both ends and the blower casing temperature are normal.

(4) System Checking

Regularly check the lubrication and cooling system of the Roots blower. Check the quality of lubricating oil and replace it regularly according to regulations. Listen carefully to whether there is noise during the operation of the blower to judge the operation of the rotor shaft and impeller.

(5) Parameter fluctuation

Overload or abnormal operation of Roots blower is gradually reflected. Pay attention to the inlet and exhaust pressure, the temperature rise of the bearing, and the operating load current of the motor at any time. If the above parameters fluctuate, the technician should comprehensively inspect the roots blowers in time to avoid further expansion of the fault.

(6) Overhaul Annually of Roots Blower In Cement Plant

Carry out the overhauled regularly every year. Check the clearance between impeller and impeller, impeller and housing, impeller and wallboard. If the clearance exceeds the allowable range, should let the professionals adjust it to ensure the safe operation of the roots blower and prolong the service life of the roots blower to the greatest extent.

Conclusion

The above is an introduction to the application of Roots blower in cement plants. If you encounter any problems during the use of the Roots blower, please contact us. We can provide you with professional technical support.

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