How to select the batching weighing module

The weighing module composed of load cells is unique in its application in chemical companies because of its flexible assembly and low price.
1. Weighing module and its characteristics 1. Introduction to the weighing module: The weighing module is a practical structural accessory for sensors. It is composed of top plate, base plate, load cell, load supporting column and supporting bolts. According to the difference of the load supporting column and the top plate, there are three structures: fixed, semi-floating and floating. In a weighing system, one fixed module, one semi-floating module are used, and the rest are supplemented by floating modules, generally divided into three sets and four sets. One set of three is used for three-point support, and one set of four is used for four-point support. The weighing module can be easily installed on containers of various shapes, and is suitable for transforming existing equipment, whether it is a container, hopper or reactor, plus a weighing module, it can be turned into a weighing system.
2. The characteristics of the weighing module: Compared with the ready-made electronic weighing instrument, the weighing module is not restricted by the site, flexible assembly, convenient maintenance and low price. Because the ground scale has a weighing platform, it needs a certain area, and the weighing module is installed on the support point of the container without additional area. It is especially suitable for occasions where multiple containers are installed side by side and the site is narrow. There are certain specifications for the range and division value of electronic weighing instruments, and for the weighing system composed of weighing modules, the range and division value can be set within the allowable range of the instrument. The weighing module is easy to maintain. If the sensor is damaged, the support screw can be adjusted to lift the scale body, and the sensor can be replaced without removing the weighing module. In addition, due to the simple structure of the weighing module, the weighing system is composed of the weighing module, and the investment is relatively small.
2. The application of weighing module in chemical enterprises: chemical enterprises use a large number of storage tanks and metering tanks in the process of material storage and production. However, two problems are commonly encountered, one is the measurement of materials, and the other is the control of the production process. According to our practice, the application of electronic weighing module can be a better solution. 1. The weighing module is applied to material measurement: Generally speaking, most of the current measurement of liquid in tanks is measured by a ruler or a flowmeter. But these two methods are measured by volume, and then converted into weight based on the density of the liquid. Because density is related to temperature and other factors, the error is relatively large. Although there are mass flow meters at present, they are rarely used by ordinary enterprises because of their high prices. Therefore, it is more economical and practical to use electronic weighing modules to directly weigh the materials. 2. Weighing module The weighing module is used for liquid level indication and control. Liquid level is an important control parameter in the chemical production process. In addition to the on-site liquid level indicator, the liquid level indicator usually uses a transmitter to convert the liquid level signal into a standard electrical signal or a gas signal to be transmitted to the control room. However, this method, in addition to the aforementioned error of the liquid level caused by the change in density, may also cause false liquid level due to material crystallization, blockage, etc., and even cause accidents in severe cases. In addition, because the measuring part of the transmitter is in direct contact with the measured medium, for some corrosive media, expensive corrosion-resistant materials need to be selected. However, the weighing module does not directly contact the measured medium, and none of the above shortcomings exist. And the weighing indicator can be selected with an analog output interface, connected to the recorder and regulator to realize automatic recording and control. 3. The weighing module is used in occasions where the feeding amount is strictly required. Some production processes have strict requirements on the amount of feed, and many companies put the metering tank directly on the ground to control the amount of feed. However, when the ground scale is overhauled or inspected, it is necessary to use hoisting equipment to lift the measuring tank down, which is more troublesome. If the electronic weighing module is used, because the measuring tank itself serves as the scale body, there is no lifting problem, and the maintenance is more convenient.
3. Precautions for the selection, installation and debugging of weighing modules: 1. Precautions for purchasing: For the selection of weighing modules, the range of 3 or 4 modules is generally selected according to the supporting point of the container. Due to factors such as the weight of the scale body (container), vibration and impact, and partial load, it is generally selected according to the following rules. Multi-sensor static weighing system: fixed load (weighing platform, container, etc.) + variable load (load to be weighed) ≤ rated load of the selected sensor × number of sensors × 70%, of which 70% of the coefficient is considering vibration, Impact and unbalanced load factors. In addition, pay attention to whether there are explosion-proof requirements. In flammable and explosive situations, explosion-proof sensors should be used.
2. Installation precautions: (1) Pay attention to horizontal adjustment, including the horizontal adjustment between the installation plane of a single module and a set of weighing modules.
(2) The sensor cannot pass current during welding. When welding the top plate, the ground wire should be connected to the scale body. When welding the bottom plate, the ground wire should be connected to the foundation to prevent damage to the sensor.
(3) If there is a feeding pipe on the scale body, it should be replaced with a hose, or the connecting pipe should be as long as possible to prevent them from eating the real load of the sensor and causing errors.
(4) Weld a weight calibration table on the container for calibration. Generally, there is no place for weights to be placed on the container, and it is necessary to weld a platform to place weights. Usually welded under the container to facilitate the placement of weights up and down.
(5) The junction box must be protected from moisture, and the excess holes should be plugged with sealing plugs. If the junction box is installed outdoors, a protective box must be added to prevent rain. In use, the junction box is damp and cause failures from time to time, so sufficient attention must be paid.
3. Precautions for debugging: (1) Before debugging, be sure to check whether the nut on the top of the support screw of each weighing module has been loosened and whether the sleeve is in a free state, otherwise, a large error will occur and even weighing will not be possible.
(2) When debugging, check whether the factory setting value of each parameter meets the actual needs, especially the "reset at startup" parameter, which is generally set to "automatic reset at startup" at the factory, and change it on the container scale. In order to "prohibit automatic resetting when starting up", to prevent the material weight of the container from being reset to zero and lost due to power failure and other reasons.
(3) The range setting does not refer to the rated total load of a set of weighing modules, nor does it include the weight of the container itself, but should be weighed according to the large material, and select greater than or equal to the number of divisions and division values given in the manual ^Large scale weight is used as measuring range. (4) The power supply voltage of the weighing indicator must meet the requirements. If the voltage is unstable and exceeds the allowable range, it will cause digital drift. ^Use a regulated power supply. Because the weighing system composed of electronic weighing modules is easy to realize the process of automated weighing and is easy to network with computers, it will be more and more widely used in chemical enterprises.