Water Test Strips 15 Parameters Detection method:
2. Put the edge of the strip against the edge of the container to remove excess water samples;
3. Compare the test strip with the colorimetric table on the bottle label, and record the test result in the determination time: 0 ~ 60 seconds. Use visual.
Storage conditions: Water Test Strips 15 Parameters,Water Quality Test Kit,Professional Water Test Kit,Drinking Water Test Strips Changchun LYZ Technology Co., Ltd , https://www.lyzstrips.com
Second, the application of the frequency converter in the centrifuge 2.1 The application of the frequency converter In recent years, the frequency converter has been continuously updated and developed as an industrial control equipment, and has been widely used in various industries. With the continuous maturity of power electronics technology, frequency conversion control theory and microcomputer control technology, the performance of the inverter is constantly improving and its functions are constantly enhanced: such as multi-speed, programmable automatic operation, communication functions, etc. An application. According to the production process of the centrifuge, the multi-speed function control of the frequency converter can be used to realize the inverter. In addition, the inverter generally has a built-in braking unit or an external braking unit, which can solve the difficulty of parking due to the inertia of the centrifuge when stopping. The problem.
2.2 Application of three-crystal SA-J8000 series inverter on the centrifuge The centrifuge load is constant torque and large inertia load. Here, the SAJ-8000G series universal inverter specially produced by Guangzhou Sanjing Company is used. In the case of motor power of 5.5kW, 6 cases, SAJ-80007R5G3 inverter is selected, and its external control circuit is shown in Figure 1. The start signal of K1 is connected to the FWD multi-function control terminal of the inverter, the K1 multi-speed 1 is connected to the MI1 of the inverter, the K3 multi-speed 2 is connected to the MI2 of the inverter, the K4 multi-speed 3 is connected to the MI3 of the inverter, and the three-speed is selected according to the need. That is, low speed operation, medium speed operation and high speed operation, the specific running speed can be set by corresponding parameters.
The application of the brake unit is a large inertia load. When the inverter is used for control, it is required to increase the brake unit to meet the requirements. However, the three-phase inverter has a built-in brake unit of 15KW and 15KW or less, which not only saves the installation space for the user. At the same time, it saves costs. It is known from the running characteristics of the motor that when the actual speed of the motor is higher than the synchronous speed, the motor runs in the generator state. When the centrifuge starts to stop, the output frequency of the inverter starts to decrease according to the deceleration time. Large, the actual motor speed is higher than the synchronous speed, the motor is in the power generation braking state, which is known by the main circuit of the inverter. At this time, the energy returned by the motor side will be fed back to the DC circuit through the freewheeling diode D1-D6 of the inverter circuit. On the filter capacitors C1 and C2, the bus voltage Ud of the inverter will rise (ie, the pump voltage). Excessive pumping voltage will cause overvoltage protection of the inverter and even damage the inverter. The brake component must be installed. When the brake unit control circuit detects that the DC bus voltage reaches a certain value, its switching transistor IGBT is turned on, and the braking resistor RB is connected to the loop, and the feedback braking energy of the motor is consumed on the resistor. To maintain the normal bus voltage Ud.
3 debugging attention to the problem According to the load characteristics of the centrifuge, should pay attention to when debugging:
(1) Centrifuge load starting torque requirement is high, there may be difficulty in starting. At this time, the torque compensation value of the inverter can be appropriately increased. The SAJ-8000-G series F009 setting parameter is 3, but the starting torque The compensation should not be too large, otherwise there may be alarms such as overcurrent (error code is OC) and overload (error code is OL). If overcurrent alarm occurs during acceleration, the acceleration time should be extended appropriately;
(2) The inertia of the centrifuge is large. If the inverter needs to stop according to the deceleration time, the brake unit must be installed. The braking resistor is selected in the inverter instruction manual. It can be selected according to the operation manual. The braking resistor works normally. It generates heat due to energy consumption, and can appropriately amplify the power of the resistor and the braking action time.
(3) The general centrifuge is installed at the operation site, and multiple inverters are placed in the control room. If the distance between the site and the centrifuge exceeds the allowable range of the inverter, corresponding treatment measures should be taken, such as rational distribution of the main circuit line and control line. Install an output reactor or filter to prevent the output voltage of the inverter from attenuating, or consider increasing the capacity of the inverter.
4 Conclusion Centrifugal machine adopts frequency conversion speed regulation, which can be adjusted according to different process requirements. It can easily select multi-speed operation according to different materials. At the same time, variable frequency control is used to realize soft start of motor, reduce the impact on the power grid, and the inverter has overcurrent. , overload, overvoltage and other rich protection functions, when the load or motor is abnormal, the inverter stops due to the fault and quickly blocks the output, so that the motor can be protected in time.
visual
Operation method:
1. Visual inspection: Immerse the test area of the test paper into the fully stirred fresh drinking water, and take it out immediately;
The test paper should be stored in room temperature, dry environment, away from a variety of chemical reagent environment, avoid direct sunlight. This product does not need to be refrigerated (if it is stored for a long time, it should be restored to room temperature and opened for use).
Introduction to the original centrifuge
Introduction of Centrifuge Originals Three-phase Inverter Energy-saving Retrofit Application on Centrifuge I. Industrial Centrifuge is one of the main equipments in the chemical industry. Industrial centrifuge is one of the main equipments in the chemical industry. It mainly separates solid and liquid by centrifugal force. From feeding, washing, dewatering, knives, unloading, etc., the feeding, washing, knives, unloading and other parts are controlled by solenoid valves and pneumatic valves. The centrifugal kettle is the main component for solid-liquid separation. It is driven by a three-phase AC motor through a belt. According to the characteristics of the process, the material is mainly solid-liquid mixture at the beginning stage. The load is relatively large when starting. When a certain speed is reached, the liquid flows out from the outside of the centrifuge under the action of centrifugal force, so that part of the liquid is separated first, along with the motor speed. Further improvement, the load is also reduced accordingly. According to the process requirements, it is generally divided into several different speeds to achieve the separation effect.