Measuring System GrindControl

The GrindControl monitors and records the development of pressure and temperature of a ball mill process.

Monitoring the two variables "pressure" and "temperature" provides valuable information about what is happening inside the grinding jar. GrindControl is used to improve sample preparation, for example of temperature-sensitive materials, to control colloidal or long-term grinding processes, or to successfully perform material synthesis such as mechanical alloying or mechanochemical processes.

The GrindControl system is available for the planetary ball mills PM 100, PM 300 and PM 400 as well as for the Mixer Mills MM 500 nano and MM 500 control and for the High-Energy Ball Mill Emax. The system consists of the pressure and temperature measurement hardware and an analysis software.

GrindControl Benefits of measuring temperature and pressure

Monitoring and documentation of the temperature and the pressure inside the grinding jar are of interest in research as well as in quality control.

It helps to improve:

Quality - Temperature and pressure can significantly affect the quality of the final product prepared in the ball mill. Monitoring these two variables ensures the quality of the final product.

Efficiency - The temperature development of a grinding process have a considerable influence on the grinding result of a material, as some material properties depend on temperatures. By monitoring the actual temperature, it can be ensured that the sample is processed under optimum conditions.

Safety - During a ball milling process, high temperatures and pressures can be potentially dangerous. Monitoring the temperature and pressure helps to ensure that the ball mill process remains within specified limits.

Error detection - A sudden change in temperature or pressure in a ball mill process can indicate that the grinding process is not running optimally. By continuously monitoring these parameters, deviations can be detected at an early point, allowing potential problems to be quickly identified and corrected.

In-situ monitoring of Mechanochemical Synthesis Reactions (MSR)

Monitoring the two variables "pressure" and "temperature" provides valuable information about what is happening inside the grinding jar. RETSCH’s GrindControl system is used to control colloidal or long-term grinding processes, or to successfully perform material syntheses such as mechanical alloying or other mechanochemical processes. The GrindControl system is available for the Planetary Ball Mills PM 100, PM 300 and PM 400, for the Mixer Mills MM 500 nano and MM 500 control and also for the High-Energy Ball Mill Emax. It comprises hardware for pressure and temperature measurement plus analysis software.

A mechanochemical synthesis was conducted in a Mixer Mill MM 500 nano, using a 125 ml stainless steel grinding jar, equipped with GrindControl for gas and pressure monitoring. The elemental precursors were introduced to the jar together with 32 x 10 mm stainless steel balls. The reaction was conducted under air atmosphere, at 20 Hz. The milling process was stopped when a sudden change in the temperature and pressure indicated the successful completion of the MSR.

The mechanically-induced self-propagating reaction event in the synthesis was monitored by using the GrindControl system. After 20 seconds of milling, an explosion took place, leading to a pressure increase from 0 to 730 mbars and to a rise in temperature. In this application, GrindControl allowed to precisely observe the ignition time during synthesis, the only parameter of interest for the reaction. [8]

Принцип на работа

A transmitter is integrated in the lid and sends the signals of the pressure and temperature sensor data to a receiver that is plugged into the PC. A secure industry standard protocol is used for transmission. To detect the temperature inside the grinding jar, the temperature sensor is thermally decoupled. A filter is used to protect the pressure sensor from contamination.
The GrindControl software is an intuitive program that allows to record the measured variables in real time making them available for later evaluation. The measurement data is transferred to the PC and a measurement protocol is stored in a consecutive measurement list. The data can be exported for further processing.