What level detection devices are available in concrete mixing plants?

The automation level of concrete mixing plants is increasing, and more and more detection and measurement devices are being used. Due to the special measurement environment, there are high requirements for level instruments. This article briefly introduces the level detection and measurement devices for raw materials.
1, Selection of aggregate level gauge
The aggregates of the concrete mixing plant are stored in the aggregate bin. The aggregates of concrete are mainly stones and sand of different particle sizes. During the feeding process, suspended dust is generated from the aggregates, which is a harsh environment for measuring instruments. In this working condition, if a heavy hammer level gauge is used, the service life is short and the maintenance workload is large; If a weighing level gauge is used, the measurement will be inaccurate, and adjusting the zero point will also be inconvenient; The use of ultrasonic level gauges in dusty environments is also not ideal; The pulse radar level gauge precisely meets the requirements of this working condition. The radar level gauge uses microwave pulse measurement method, which is suitable for situations with large changes in dust, temperature, pressure, and the presence of inert gases and steam. Therefore, pulse radar level gauges are preferred in the selection of aggregate silo level gauges.
2, Selection of level gauge for powder silo
The main materials used in the mixing plant are cement, fly ash, and mineral powder. Most of the powder in modern concrete mixing plants is stored in cylindrical powder silos and supplied through pneumatic conveying. There are factors such as dust, high temperature, humidity, and dust adhesion in the warehouse. The correct measurement of the material level in the warehouse is helpful for the normal transportation of the powder supply system in the entire mixing plant and the interlocking of the control system. Generally, resistance rotary level gauges and pulse radar level gauges are used. The controller of the resistance rotary level gauge adopts the principle of electromechanical level control, which measures the level of the material through contact, and the results are true, accurate and reliable; It can be installed horizontally, obliquely, and vertically, making it easy to install and use. It is currently the most commonly used level gauge in powder silos, and compared with pulse radar level gauges, it has the advantages of simple structure and low cost.
3, Liquid level gauge
There are many liquids used in the raw materials of concrete mixing plants, including water and various additives. The water used in concrete mixing plants is stored in water tanks or reservoirs, with float level gauges being the most commonly used. A float type liquid level gauge is a device specially developed for liquid level measurement based on the magnetic principle, Archimedes principle, and other clever combinations of mechanical transmission characteristics. It is easy to install and requires different materials of floats and sealing gaskets to be selected and used for different liquids; In liquid level measurement, ultrasonic level gauges are also commonly used. During the level measurement process, the ultrasonic signal is emitted by the ultrasonic probe, reflected by the surface of the liquid or solid material, and then folded back. It is received by the same probe to measure the entire operating time of the ultrasonic wave, thereby achieving level measurement. Ultrasonic level gauge is a non-contact measurement method that solves the disadvantages of traditional measurement methods such as pressure, capacitance, float, etc., such as entanglement, blockage, leakage, medium corrosion, and inconvenient maintenance.
The above are several commonly used level measurement tools in modern concrete mixing plants. With the development of technology, laser level gauges with higher measurement accuracy and adaptability have been introduced and used in small quantities in the market. Accuracy and adaptability are the factors for selecting level gauges in the future, while considering intensive production may be the direction for the future development of level gauges.