In many industries, the accuracy of weighing ingredients in the reactor tank is an important factor related to product quality. Therefore, as a weighing device for weighing ingredients in the reactor tank, the weighing module can weigh the weight of the required materials without touching the materials. Compared with the traditional sensor, it has the advantages of good stability, high precision, easy installation, preventing measurement errors caused by improper installation, and reducing the influence of external environmental factors on weighing. With the continuous development of industrial automation production in China, weighing module has been widely used in many industries.
1. Characteristics and working principle of weighing module
Weighing module is a new type of weighing unit that combines high-precision sensor, load transfer device and mounting coupling device. This device is not affected by installation conditions and environment, and can avoid the risk of weighing error caused by installation while ensuring the stability and accuracy of the sensor. The weighing module is mainly composed of a top plate, a bottom plate, a weighing sensor, a pressure head of a sensor and a supporting bolt. The weighing module is characterized by compact structure, reasonable and simple design, all components do not need to be welded, and there are no other additional accessories, because all weighing modules are produced, installed and tested according to the standard, so it can be very convenient and fast installation and debugging.
In the reactor tank batching system, a fixed weighing module is usually used in combination with other floating and semi-floating weighing modules, so that the weighing system can ensure that the force point of the sensor on the weighing module remains unchanged when the displacement is caused by thermal expansion and cold contraction. This can not only ensure the high precision and good long-term stability of the weighing sensor, but also prevent the measurement error caused by improper installation.
The working principle is that the weighing module generates analog electrical signals proportional to the weight of the reactor tank, and then the analog signals of each weighing module are connected to the junction box through parallel connection. We can adjust the output of the weighing module according to the respective stress conditions of the weighing module, and then transmit the summarized signals to the weighing display terminal to display the weight data. The junction box and the weighing display control terminal should be selected according to the requirements of the site, and different protection levels and explosion-proof levels should be selected.
2. Installation of weighing module
In the weighing dosing system of the reactor tank, the selection, installation and debugging of the weighing module will directly affect the measuring accuracy of the whole dosing system, so the design and installation should be careful. The material of the weighing module should be determined according to the environment of the use site, if there is contact with corrosive chemical raw materials, stainless steel weighing module should be used, and the requirements of explosion-proof should also be taken into account. Weighing module is installed with the support point of the reactor tank as the force point, and the rigidity and straightness of the support are good, and the number is generally composed of 3 or 4. All weighing modules should be installed on the same horizontal plane and evenly distributed, so that the weight of the reactor tank can be evenly distributed on the weighing module, so as to ensure that the force on the weighing module is uniform and vertical. Make the loading force on each weighing module close to the same to reduce the error caused by the influence of the support structure on the weighing module.
When installing the weighing module, the electric welding operation should be strictly prohibited, so as to avoid the current passing through the weighing module and damaging the weighing sensor in the module. If the welding operation is necessary, the ground wire should be directly connected to the tank body, and it must be noted that the current loop cannot pass through the weighing sensor in the weighing module to prevent the sensor of the weighing module from being damaged. In the actual use process, the weighing module will be affected by wind, vibration and other environments, thus affecting the measuring accuracy of the weighing module. In the weighing dosing system of the reactor tank, the inlet and outlet of raw materials and finished products are mainly pipeline transportation, so the connection between the pipeline and the reactor tank is particularly important, if the connection is improper, it will affect the normal use of the weighing dosing system of the reactor tank, resulting in a great deviation. Therefore, the pipeline connected to the reactor tank should be connected with a hose, and the support of the pipeline should be installed on the framework of the reactor tank, and should be laid horizontally to prevent the pipeline from causing a restraining force on the reactor tank, resulting in errors, to ensure that the weight of the reactor tank * acts on the sensor of the weighing module.
3. Debugging of weighing module
After the reactor tank weighing dosing system is installed, the system should be adjusted and calibrated. The commonly used debugging and calibration methods include standard weight method, substitute method and standard signal analog calibration method. The standard weight method is to gradually load the standard weight from zero to the scale, and then gradually unload it to the empty scale for calibration. The result of loading by this method is accurate, but it requires that the weighing dosing system of the reactor tank is equipped with a platform support or hook for placing the weight. The alternative method is relatively simple, that is, when only a small number of weights can be used for calibration, only other alternatives can be used for calibration, and the standard weights are repeatedly compared with other alternatives from the zero point of the empty scale. In addition, when the standard weight cannot be used for calibration, the quality of the alternative can only be weighed on another high-precision scale, and then the alternative is put into the reactor tank weighing dosing system for calibration. The alternative method is the usual method for the calibration of the reactor tank weighing dosing system. The standard signal analog calibration method is to replace the signal output of the weighing module with the standard signal source to simulate the empty scale value and full scale value of the weighing dosing system of the reactor tank, and calibrate the scale by adjusting the output of the standard signal source. This method has certain influence on the accuracy of the weighing dosing system of the reactor tank, and is generally not used.
4. Later maintenance of weighing module
During the use of the weighing module, regular inspection should be carried out to clean up the debris and materials on the weighing module to prevent jams, check whether the limit in the weighing module is reliable, check the safety and fastness of the wiring of the weighing module, and carefully check the connection of the pipeline and support on the reactor tank to prevent the restraining effect and ensure the normal operation of the weighing module. The reactor tank weighing batching system must be equipped with lightning protection to prevent lightning damage to the sensors in the weighing module, so each weighing module must be well grounded.