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Three-Phase Decanter Super Centrifuge System and Improvement Tang Liming Zhang Keyu Tangshan Rui Feng Steel Group Co., Ltd. (Hebei Tangshan 063000) Abstract: In order to ensure that coal tar tar processing operations in the quality of Tangshan Rui Feng Iron & Steel Group Co., Ltd. coking plant introduced two high-speed three-phase Decanters. Address the problems during the operation, its application process and external control components to a reasonable improvement to make centrifuge system more stable, reliable, improve the productive capacity of tar distillation equipment. Keywords: coal tar, high-speed three-phase dewatering Decanter Centrifuge links off valve 1 Introduction Coking processes crude tar is the cycle of ammonia gas with the spraying and cooling the beginning of cooler to be recovered in the condensate, which contains large amounts of water. While standing by heating dehydration, when admitted to tar processing operations are still about 4% of its water content, and sometimes even up to 8% ~ 10%. Tar contains more moisture during distillation negative. Tar distillation kettle, tar water and more time will be extended dehydration reduce equipment productivity, increase heat loss. Particularly in the water in the tar to form a stable emulsion, when heated to form emulsion droplets, evaporation and overheating can not immediately start, when the temperature continues to rise, the water droplets evaporate rapidly, resulting in a sudden occurrence of red oil boiling and accident. To prevent similar incidents in the dehydration during the heating must be slow, so extended distillation time. In addition, the tube furnace continuous distillation system, such as tar and more water will lead to significantly higher system pressure, the resistance increased, disrupted the operation of the system. At this point, to reduce the tar processing capacity, or equipment because of high pressure pipeline rupture caused a fire. Therefore must be dehydrated to tar distillation processing. Therefore, install a recovery system can be used to tar dehydration, slag off the equipment is imperative, three-phase (solid? Liquid? Liquid) Decanter centrifuge systems can solve the problem. Coking plant personnel completed the self-recovery system, centrifuge system installation, cable laying, control cabinet wiring, operation cabinet wiring, equipment and commissioning work. And specific issues for a centrifuge system maintenance and improvement, has run well, obviously. 2 centrifuge system introduced 2.1 centrifuge body Need to separate the feed material through the center tube into the centrifuge, the centrifugal force, the density of the solid settlement to the drum wall. The clear liquid two-phase density of the formation of concentric cylinders of different, less liquid in the inner layer, the heavier liquid in the outer layer. Rings of different thickness of liquid overflow weir can be adjusted to change the impeller and variable. Deposited on the drum wall of solid (black) sent by the screw conveyor to transfer cylinder cone end of the exit from the nesting box into the solid bulk material. Discharge the moisture content of solid and liquid clarity can change the following ways: (1) adjusting weir plate, to change the depth of liquid Weir plate diameter increases, the drainage area increases, solid moisture content can be decreased; reduce the weir plate diameter, increasing depth of liquid, clear liquid in the solids can be decreased. (2) changing the rotor speed Finer solid particles, the higher the rotor speed required to achieve satisfactory separation. (3) to change the differential screw Drum and the spiral of differential smaller solids discharge rate, the lower water content; higher feed solid content, the higher the required differential. Machine running the best parameter settings need to be determined after careful debugging. 2.2 centrifuge control system introduced Centrifuge control system Siemens S7-300 series PLC, mainly from the rack, CPU processing module, signal modules, function modules, interface modules, Communicate Processor, Power supply Modules and other components. PLC Acquisition external signal: (1) PLC DI signal major acquisition: three-way valve condition, clean with a solenoid valve status signal, centrifuge vibration alarm, gear oil level signal, drive motor over temperature alarm (2), emergency stop button and alarm signals, spiral differential signal, drum speed signal, Inverter Fault signal, the air switch state signals. (2) PLC main output of the DO signal: spiral start signal, drum start signal, three-way valve start signal, clean start with a solenoid valve signal. (3) PLC signals major acquisition of AI (4 ~ 20mA): screw driver torque signal, drum-driven power signal, feed temperature. (4) PLC AO main output signal (4 ~ 20mA): screw driver set signal, drum drive setting signal. 2.3 control system structure and composition (1) centrifuge control cabinet: including air switch, frequency converter, AC contactor, intermediate relays, transformers, programmable logic controller (PLC) and the operation panel (OP). (2) high-speed centrifuge site is three-phase explosion-proof cabinet Decanter main operating unit, which directly affects the operation of the normal and stable operation of centrifuges. (3) external control of centrifuge components, including: temperature Sensor , Three-way valve, cleaning valve, vibration sensor, speed sensor, oil level switch. 3 specific issues arise during the operation Centrifuge system specific issues arise during the operation: (1) three-way valve can not find the location of the feed centrifuges, that part of the material through the bypass, part of the material through the centrifuges, can not fully address all the tar, the significance of loss of use of centrifuges; (2) Ontology centrifuge drum drive motor is not running, causing centrifuge system does not work; (3) centrifuge during normal operation after a sudden failure, from the slagging pipe "leak tar", cause environmental pollution. 4 Maintenance and Improvement Centrifuge system for problems, one by one, the maintenance and some reasonable improvements: (1) three-way valve (Figure 1) can not find the location of the feed centrifuge manual control three-way valve hit the feed position (into the centrifuge) or bypass position (drain tube ), the spool in one direction always rotating, and the two positions can not be found (in live action plate position indicator shall prevail). Open the valve cover part of the control analysis, respectively feed (OPEN knob), bypass (CLOSE knob) the location of the two adjustable knob to adjust. The specific method is: 1) the three-way valve to the centrifuge feed roll position, its We are high quality suppliers, our products such as China Paper Machine Clothing , Plain Fabric for oversee buyer. To know more, please visits Polyester Mesh.
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