1 DVC6000 Series Electric Valve Positioner 1.1 function DVC6000 series electric valve controller is a digital communication that EMERSONF ISHER company can communicate with, using HART communication protocol to access the important information of process operation, and based on the microprocessor's electrical switching valve controller. The series of positioners are simple in structure and consist mainly of I/P converters, printed circuit board (PWB) components and pneumatic amplifiers. The highly modular integration facilitates on-site disassembly and replacement. Its powerful function, in addition to the automatic calibration stroke and the output of the A and B port pressure, input air source pressure, input current signal, valve position signal and other conventional intelligent positioner have functions, through the HART handheld device can also provide Other functions such as the working range of the stroke sensor, the positioner temperature display. These are very helpful in analyzing and judging the locator failure and solving it quickly. It is worth mentioning that the DVC6000 series also provides AUX auxiliary terminal. By setting the terminal, it can realize various auxiliary functions such as automatic check stroke without manual communicator, auxiliary input alarm, program modification protection. 1.2 Classification DVC6000 series digital valve controller mainly includes DVC6005 split type controller, DVC6010 is used for linear actuator (maximum stroke to 4 inches), DVC6020 is used for long stroke straight stroke actuator (4~24 inch stroke) and rotary actuator The DVC6005 is used in longitudinal rotary actuators. Our factory mainly chooses DVC6010 to replace part of FISHER's 3610 series linear electric valve positioner. DVC6020 is used to replace part of FISHER's 3610 series angular stroke electric valve positioner. DVC6005 is used instead of H+B air compressor inlet and turbine guide. Leaf position controller. 2 DVC6010 and DVC6020 applications (1) The inlet and outlet control valves between the main tank-shaped equipment of the oxidation unit are all straight-angle angle valves produced by SCHUFF for high temperature and high pressure difference. The control requirements are high precision, the action frequency is high, and the equipment operating conditions are bad. The failure has a great impact on the production of the device, which requires high stability of the equipment operation. DVC6010 digital valve controller in the application of SCHUFF straight-angle angle valve, its working accuracy, flow characteristics, rated air supply pressure, explosion-proof level, input signal form, wiring, communication protocol, etc. can meet the equipment requirements. Especially the installation is convenient, only need to process the appropriate feedback rod, the adjustment is simple, the stability is good, the positive and negative effects can be converted, and the zero/range adjustment is convenient. (2) DVC6020 digital valve controller in the FISHER1052 actuator application, because it is the matching product of the same manufacturer, can be directly installed, only the corresponding short feedback arm provided by the manufacturer (the distance from the roller to the rotating shaft is 54mm) And then verify that it is correct. (3) A valve operation diagnostic system is connected to several important control valves. Use VL2000 software to set some parameters of DVC series positioner and valve, checksum information diagnosis. Once the VL software is properly installed, it can properly set and display alarms inside the device. These displays and alarms help the operator to properly troubleshoot and analyze faults on the field equipment to avoid factory or process site equipment jumps. The description of a simple fault or error displayed by an internal alarm is quite useful and easy to achieve prior maintenance and proper understanding of it. The staff can continuously monitor the health status of the smart equipment in the maintenance workshop or control room, and can find the equipment problems in time, so as to avoid the major losses caused by the failure to be eliminated in time; and reduce the number of round trips from the repair shop to the scene. Reduce the amount of inspection time, so that maintenance personnel can concentrate on handling predictive maintenance events, thus greatly reducing maintenance labor costs; can provide equipment failure judgment basis for preventive maintenance (planned maintenance), thereby reducing preventive maintenance manpower input And the spare parts input; with the online configuration function, the maintenance personnel can modify the intelligent device configuration in the maintenance workshop or the central control room (even in the office), without querying the circuit wiring diagram, no need to go to the site to check the line: in short, the valve can be operated All repairs and alarms are well documented, which increases the safety of the entire plant. 3 DVC6005 application 3.1 Features The C1113 air compressor inlet and turbine vane position controller are the core equipment for the air compressor control of the oxidation unit. The normal operation of the compressor directly affects the load and energy saving of the air compressor. Since the start of the oxidation unit in July 1995, the inlet and turbine vane position controllers have been running for 15 years, and the vane position is unstable, the opening is not enough, the adjustment is difficult, the linearity is not good, and so on. The press is smooth and runs at full capacity. To this end, FISHER's DVC6000 series intelligent valve positioner was used instead of the original vane position controller. The DVC6005 has a remote feedback access terminal function, which can pass the original guide vane cylinder position feedback resistance signal through the series-parallel resistance to meet the condition of the feedback position signal of the intelligent positioner, thus forming a closed-loop control loop to ensure the accurate and stable execution mechanism. jobs. 3.2 Working principle The air compressor inlet and the turbine vane actuator are double-acting actuators, and the feedback signal is a linear variable resistance signal of 0~7k. 3.2.1 Working principle The input signal enters the terminal box through a twisted pair and then enters the printed circuit board assembly sub-module where it is read by the microprocessor, processed by a digital algorithm and converted to an analog I/P drive signal. When the input signal increases, the output air pressure to the I/P increases. The I/P output air pressure is sent to the pneumatic amplifier sub-module, which is also connected to the input air source to amplify the air signal from the I/P. The pneumatic amplifier receives the amplified pneumatic signal and provides 2 pneumatic outputs. As the signal increases (4 to 20 mA signal), the air pressure at output A increases and the pressure at B decreases. The increase in air pressure at output A drives the actuator lever to move downward, the actuator stroke sensor detects the change in position of the actuator lever, the actuator stroke sensor is connected to the printed circuit board assembly sub-module via an electrical signal, and the actuator stem continues to move downward until Achieve the correct actuator stem position. At this point, the printed circuit board assembly stabilizes the I/P drive signal 54 polyester industry volume 23, which positions the baffle to prevent further increase in nozzle pressure. When the input signal decreases, the drive signal to the I/P converter sub-module is reduced, thus reducing the nozzle pressure. The pneumatic amplifier reduces the air pressure of A and increases the air pressure of B. The actuator rod moves up until the correct one is reached. Actuator lever position, at which point the printed circuit board assembly stabilizes the I/P drive signal, which positions the baffle to prevent further reduction in nozzle pressure. Thereby achieving the correct positioning of the actuator. 3.2.2 Implementation of feedback The stroke feedback signal of the DVC6005 split electric valve positioner is designed to receive a linear 40k potentiometer change. The feedback signal of the vane actuator of our factory is a linear potentiometer of 0~7 k, due to the feedback of DVC6005. The terminal box comes with a specified resistance of 30k, and it is connected into the feedback wiring, so that the feedback resistor 7k of the original vane actuator of our factory plus the fixed resistor 30k is equal to 37k, which is closer to the requirement of the feedback signal of DVC6005. 3.2.3 Analog signal conversion Since the air compressor turbine system requires an actual opening feedback signal of the turbine guide vane to enter the PLC, the operating load and safety of the equipment are controlled. Use the DVC6005 digital valve controller with the Rosemount 333 HARTTriLoopTM HART analog signal converter, which can be used to obtain the corresponding analog input signal from the signal output via the HART protocol, valve travel setpoint, actuator pressure or valve stroke independent 4~20mA analog output signal. HART TriLoop accepts any of these 3 digital signals and converts them into 3 independent 4-20 mA analog signals. In order to make the digital valve controller work with the Model 333 HARTTriLoop, set the digital valve controller to BurstMode Enable, select BurstCommand4 (valve stroke). After wiring, pass the system test to complete the analog input signal of the actuator feedback signal. 4 Conclusion Through the application of the DVC6000 series electric valve controller, it is found that the new intelligent valve controller is compared with the general valve positioner, and its advantages are: (1) It is only necessary to change the set value for various types of valves, without having to replace hardware (springs, cams, etc.); (2) The range of the range can be set arbitrarily; (3) It is possible to easily set the gap adjustment and the cover adjustment, and can freely specify the flow characteristics, in addition to the linear characteristics, the quick opening characteristics, the equal percentage characteristics (EQ%), and the flow characteristics that conform to the characteristics of the process flow; (4) Easy installation and debugging, simple maintenance, saving spare parts, higher stability and better control performance; (5) It can communicate with DCS or handheld communicator, and the verification is faster and more convenient; (6) Perform valve diagnosis, understand the overall performance of the valve, understand the dynamic response of the valve, diagnose valve problems, and perform predictive maintenance. Hepa Air Purifier,Air Purifier For Allergies,Hepa Filter Air Purifier,Air Purifier For Dust Guangzhou Join Electronic & Technology Co., Ltd , https://www.alef-hesed.com