There are three series designed by an iron concentrator, among which series I and II are oxidized ore series and series III are primary ore series. In 2018, in order to further improve the grinding grade and processing capacity of series Ⅲ primary ore, a wet preseparation system was added before grinding in the primary ore beneficiation process, which is dry sieve and wet separation). When the system is in normal operation, wet preconcentration concentrate is -6mm product. After preconcentration by magnetic separator, comprehensive human grinding raw ore grade can be increased by more than 1 percentage point, and the average daily output can be 0.46mm tail ore 700t. The dry screen part before preconcentration uses 2 single layer banana screen. In order to ensure the smooth operation of the equipment, the paper analyzes and improves the application situation and the faults in the actual production.
1 Device Introduction
1.1banana screen is mainly composed of spring, motor, box shaker, intermediate shaft, drive shaft, screen frame, screen beam, screen plate rail seat, polyurethane screen plate, etc. Its main component models and specifications,
1.2 How banana screen works
According to the principle of equal thickness screening design, using continuous multi-angle screen surface, suitable for dry screening containing a large number of fine grained materials. The screen surface is composed of 6 sections of different inclined angles of the screen surface, which the inclined Angle of the screen surface at the feeding end is at most 25°, and the Angle of the inclined Angle of the screen surface at the discharging end gradually drops to 5°. Screen surface design inclined Angle gradually decreasing, so that the material through the different screen surface flow rate is different, feeding UI tilt Angle, flow rate is large, fine material can be closer to the screen surface earlier and high speed through the screen, to reduce the thickness of the material layer, screening efficiency compared with the traditional classification screen increased by 50%~100%. Single screen surface screening area 26.28m2, screen size 22mm×8mm, screen Angle 6°, amplitude 9~13 m, motor power 55kW, maximum processing capacity 3200t/h; The material is fed continuously and evenly, the feeding speed is 0.5-0.8m /s, the thickness of the material layer is equal, the feeding size is -12mm, and the maximum height of the material drop should not be higher than 500mm banana screen. Main advantages: (1) simple and compact structure, large stiffness, high strength, balanced force distribution, and high safety factor. (2) Light weight, small power, high vibration intensity, high screening efficiency, large material handling capacity. (3) The use of eccentric block external box type vibrator, double side box type vibrator coaxial connection, rotation at the same speed, to ensure that the direction of excitation force is the same, screen book and box type vibrator long service life. (4) The sieve plate is made of polyurethane, with low noise and long service life. (1) The bearing seat and bearing of the main drive shaft of the transmission device are easy to be damaged. (2) There is abnormal sound in the vibrator, and even damage in serious cases. (3) cross universal coupling abnormal sound, damage. (4) After using for a period of time, the screening efficiency decreases and the products under the screen decrease. (5) Uneven discharge at the discharge port, stacking to one side. (1) The equipment management system and system are not established and improved, the equipment management responsibility is not clear, and the important spare parts ledger is not fully established. (2) Post inspection and professional spot inspection are not in place, and failure to timely discover and deal with abnormal sound, abnormal vibration, abnormal and other faults.
(3) Lubrication and maintenance are not carried out in strict accordance with the five standards of lubrication, and lubrication is not timely. (4) The frequency of daily equipment joint inspection is less, which is mere formality, and the supervision of equipment management is not in place. 5 Improvement measures (1) Bearing seat transformation. The original bearing seat uses two stud bearing seats with equal diameter holes. The upper cover of the bearing seat is fixed with the lower half of the bearing seat through two bolts, and the lower half of the bearing seat is fixed with the frame through two bolts. Although it has the advantages of easy disassembly and installation, there are many fastening links in the bolt connection, and the radial bearing capacity is weak. Under the joint action of periodic vibration of banana screen and tension of Angle belt, it is easy to appear bolt loosening, screw thread damage, bearing seat damage, bearing damage and other phenomena. Once parts are damaged, they must be stopped for treatment, and even stop accidents occur in serious cases. After research, the bearing seat was changed into one piece, the material was changed to 45 steel, the radial thickness of the bearing seat was increased, the original 2 sets of bolt fastening link was reduced to 1 set of bolt directly fastened with the frame, the strength of the bearing seat was increased, the radial bearing capacity was increased, and the tension force of the Angle belt was adjusted reasonably, so as to ensure the smooth transmission of the Angle belt and not slip, and the service life of the bearing seat and bearing was prolonged. Reduce staff maintenance labor intensity.
(2) Strengthen the daily maintenance of box type vibrator. The contact surface between the shaker and the bracket must be clean and tidy before assembly. After the initial operation of the box shaker for 50h, the bolts should be checked for fastening, and then once every 3 months: Correct selection of lubricating oil, according to the manufacturer's instructions and production requirements, choose Mobil VG68 gear oil, Mobil 600XP68 or Kunlun heavy duty industrial gear oil KG68, while ensuring reasonable filling amount (Figure 4) : strengthen daily inspection.
(3)banana screen cross universal coupling abnormal noise treatment. Replace the short cross universal coupling to solve the problem of abnormal sound and ensure the normal use and power output.
(4) Improve the professional quality of equipment management personnel, and build a professional and high-quality management and operation team. Continuously improve the professional skills and responsibility consciousness of equipment management personnel, hire professional and technical personnel from manufacturers to carry out point-to-point explanation training: carry out targeted training for post workers and equipment maintenance workers, improve the skills and operation level of front-line workers, and provide technical support for the smooth completion of production tasks; Establish the corresponding incentive mechanism to stimulate the enthusiasm and initiative of employees to their own work, to ensure the effective implementation of equipment management work; Strengthen the joint inspection of equipment, adhere to the activity of equipment joint inspection once a week, timely summary of equipment hidden dangers, feedback, ordered rectification within a time limit, timely eliminate equipment hidden dangers, to ensure the safe operation of equipment.
(5) Strengthen inspection, strictly implement equipment inspection personnel, fixed point, fixed quality, quantitative, fixed method, fixed period of "six fixed" work method. Establish and improve equipment inspection system, clarify equipment responsible person and post responsibilities, to ensure that each equipment has a dedicated responsible person. At the same time, determine the inspection route, formulate equipment inspection records, increase the inspection frequency of key parts, carefully check inspection records and operation parameters, and timely discover and handle problems. Do a good job of seasonal management. According to the degree of cold and frost prevention of banana screen, electric heating, cotton curtain, tropical heating materials are equipped in winter, and the inspection of unattended equipment and pipelines such as side, far and alone is strengthened.
(6) Strengthen lubrication management, for the main lubrication parts, in accordance with the equipment lubrication of fixed, fixed, regular, fixed quality, quantitative "five fixed" principle, develop a detailed "five fixed lubrication table", clear equipment lubrication responsibility, in accordance with the five fixed requirements of lubrication lubrication completed parts lubrication maintenance.