VIBRA MASCHINENFABRIK SCHULTHEIS

Transcription

1 Page 1 of 7 Spare parts phone: 069 / fax: 069 / with Motor Vibrators or Electromagnetic Vibrators Operating Instructions Content Page 1 General technical information Installation In-house transport Installation instructions Further instructions Guidelines for Commissioning Motor vibrators Electrical Connection Adjustment Facilities Electromagnetic Vibrators Electrical Connection Adjustment facilities Vibration stroke limit Vibrating conveyors with cooling deck Routine inspection Fault detection and correction Summary of safety hazards (analogous to European Standard 292) 7

2 Page 2 of 7 1 General technical information The conveying action on vibrating conveyors is caused by the vibration of a conveyor deck, whose vibrational direction with respect to the deck level forms what is called the projection angle and whose acceleration in the vertical direction is greater than the acceleration due to gravity. The material conveyed is transported by socalled microprojections. The characteristic behaviour of material on vibrating conveyors has already been the subject of numerous studies. However the characteristic behaviour, which takes into account all product properties (granular size, granular structure, bulk density, temperature, moisture content etc.) have not yet been defined exactly enough to enable experimental investigations to be dispensed with in special cases. Basically, however, it can be said that the conveying capacities of vibrating conveyors, for material in a range possessing good to bad conveyability characteristics, are based on a conveying speed between 5 and 15 meters per minute. It must also be mentioned that, where the acceleration remains constant, the conveying capacity increases significantly with decreasing frequency. The required directionally rectified vibrations are generated either by electromagnetic vibrators, whose vibrations are translational due to the principle of the generating method, or by means of contra-rotating synchronized out-of-balance motors, where the generated components of circular vibration which are perpendicular to the conveying direction balance one another out. Synchronization is automatic under certain conditions i.e. the installation of special synchronizing gears is not necessary. Due to their practically maintenance-free and low-wear operation, ease of control, cleaning and dust protection, vibrating conveyors are today successfully used in conveying countless products. 2 Installation 2.1 In-house transport The applicable accident prevention codes must be observed when carrying out in-house transportation. Vibrating conveyors can, for example, be transported suspended in slings (see Fig. 1). The integrally cast lugs on the vibrators may not be used for transport purposes. 2.2 Installation instructions The vibrating conveyors are installed using the flexible spring elements provided (helical compression springs, rubber springs, tension springs). Any transport safety material left on must be removed.

3 Page 3 of 7 It must be ensured that the machines are able to vibrate freely. Feed chutes and other stationary parts must not come into contact with the vibrating conveyor during operation, on start-up or during the vibration decay phase after shutdown. Dust protection collars must be sufficiently flexible to ensure unimpeded vibration. Canvas, straining cloth, plastic coated webbing or soft rubber (up to max. 3 mm thick) can be used as material for the compensators. In the case of closed systems a minimum gap for the compensator transition pieces, between the stationary and covibrating openings, of 80 mm for motor vibrators and 50 mm for magnetic vibrators must be maintained. Vibrating conveyors used for bin discharge must not be exposed to overload by the bulk material column. The bulk material pressure can be reduced by suitably designed bin outlets (see Fig. 2) or by the insertion of baffle plates in the bin outlet. The product column may rest on the feeding deck of the conveyor in the case of small bin openings or low bulk material pressure. Vibrators and vibrating conveyors with suspension springs mounted above walkways within the working area must be secured by arrester cables for safety reasons. 2.3 Further instructions Vibrating conveyors are vibrating systems specifically designed with respect to dimensions, weights and vibrators. For this reason the machine supplied must not be increased or reduced in length or loaded with additional attachments (covibrating chutes, funnels, covers etc.). The vibrator motors are to be wired so that they rotate in opposite directions. 3 Guidelines for Commissioning After all transport safety material has been removed all screw connections are to be checked for secure seating before commissioning. All screw connections on vibrating parts must be secured with self-locking nuts and those on secondary components must be secured by spring washers (minimum requirement). After commissioning, all bolts have to be retightened according the following table: 1. After 10 minutes of operation all bolts have to be retighten with a torque wrench according the values in the following table. 2. After 2 hours of operation all bolts have to be retightened. 3. After 24 hours of operation all bolts have to be retightened. Standard values when using a torque wrench: M Nm ( 8 kpm) ; M Nm ( 20 kpm) ; M Nm ( 40 kpm) ; M Nm ( 70 kpm) : M Nm (130 kpm)

4 Page 4 of 7 4 Motor vibrators 4.1 Electrical Connection The vibrator motors must be protected against inadmissible overheating by the use of bimetallic relays and they must be electrically interlocked so that the failure of one vibrator motor will cause a complete shutdown to take place. The vibrator motors must be wired so that they rotate in opposite directions. Circuit diagram SKS 4243 supplied by us is to be consulted here. In order to avoid excessive vibration when going through the resonance vibration phase after switching off we recommend the attachment of an electronic braking device. 4.2 Adjustment Facilities The conveying capacity can be influenced by the vibration (stroke).the working moment of the vibrator motors is altered by adjusting the out-of-balance mass. Access can be gained to the out-of-balance flywheels, which are located at the ends of the shafts, by removing the protective cover. The inner out-of-balance flywheel can be adjusted by loosening the clamping screw. A 10 to 100 scale gives the percentage value of the working moment which has been set. The adjusted value can be recorded on the memo plate located underneath the terminal box, so that the adjusted vibration amplitude can be read off at a later date without removing the cover. It must be ensured that all out-of-balance masses on the two motors are set to similar values. Please note the special operating instructions for the vibrator motor. 5 Electromagnetic Vibrators 5.1 Electrical Connection The electromagnetic vibrator is directly connected to the thyristor controller, type VST. Further details can be found in the thyristor controller operating instructions. 5.2 Adjustment facilities The maximum vibration width (and thus the conveying capacity) can be varied using a setpoint potentiometer on the thyristor controller. Further modifications can be found in the thyristor controller operating instructions.

5 Page 5 of 7 6 Vibration stroke limit The vibration stroke is defined as twice the amplitude and can be easily read off during operation from a vibration width label. When adjusting the vibration stroke the following limits are admissible and may not be exceeded without our agreement: motor vibrations Frequency maximum stroke [min -1 ] [Hz] [mm] , , ,1 All deviations from the values specified in the operating instructions or the report are impermissible without the prior authorization of the manufacturer and render all warranty claims invalid.

6 Page 6 of 7 7 Vibrating conveyors with cooling deck The following must be noted for vibrating conveyors which are equipped with cooling deck: The cooling circuits must be carefully deaerated before commissioning. If the vibrating conveyor is taken out of service for a long period of time the cooling medium is to be drained off in order e.g. to prevent freezing and bursting at low temperatures. Separate cooling circuits may not be installed in series. The hose connections for water may be made using elastic hoses only. The hoses must be installed with bends and may not chafe against any object. The hose connections must be checked at least once annually for damage and are to be replaced if necessary. Maximum operating pressure: 5 bar abs. Minimum operating pressure: 4 bar abs. Maximum recirculation temperature: 60 C approx. 8 Routine inspection every 300 h and after shut down: visual check of bolt connections from outside every 1500 h and after shut down: retighten motor bolts/saddle bolts every 1500 h and after shut down: all other bolts or connection 9 Fault detection and correction Fault possible cause remedy/action conveyor is not conveying motors running in different directions change direction of rotation of one motor (motors must rotate in the same direction) excessive noise, rattle loose dust cover tighten defective motor bearing replace unevenly loaded compression springs shim irregular machine vibration unevenly adjusted eccentric weights equalize out-of-balance setting loose motor retighten

7 Page 7 of 7 10 Summary of safety hazards (analogous to European Standard 292) hazard cause, description remedy/action bumping, pinching suspended machines install barriers, use coloured markings suspended machines or motors fall down, overturning of machines install additional safety cables, collision protection (fork lift truck!), never climb up onto the conveyor pneumatics under pressure release pressure before working, observe inspection instructions compression springs dying out of machines install rubber sleeve maintain minimum clearance to stationary parts catching and winding vibrating motors operate only with cover electrical hazard water contacting live parts observe protective system chafing cable eliminate thermal hazard vibration hazardous materials hot walls due to product temperature or thermal process hot, liquid heat-transfer medium in heating systems operation of other machines affected hazard to health contact with contaminated, toxic or otherwise hazardous materials processed in the system undesired chemical reaction between the product and heating/ cooling media safeguard against accidental contact, warning signs, insulate allow equipment to cool down before starting maintenance work use only VIBRA springs, eliminate rigid joints between environment/ frame and vibrator avoid contact with vibrating parts provide protective gear, issue warning install warning system risk due to braking unit failure high amplitudes after shut-down mainstain minimum clearance to stationary parts