Innovations in stirring technology field

What is new at Herbst?

Here you will find the latest updates from Herbst. Subject can only be information on our products and current projects.

Temperature measuring system with infrared transmittance of the measured data.

One of the most frequent tasks in mixing processes is measuring the product temperature; often of importance is the almost exact measuring of the process control, whereby the positioning of the temperature sensor in the mixing bowl plays an essential part. Generally the temperature sensors are stationary and being brought into contact with the product through the bowl bottom, the bowl jacket or the bowl hood. Especially middle to high viscous products can cause problems, because no representative measuring data can be evaluated of the height of the mixing bowl due to the varying temperatures. Even the flow pattern of the stirrer can influence the locally registered temperature. Furthermore, a temperature difference between bowl jacket and bowl middle can be registered. One can achieve an improvement by operating several temperature sensors.
The optimal temperature measurement can be obtained by moving the sensor through the product during the mixing process. This is the case for example with planetary mixers. The sensor and a transmitter are integrated in the stirring tool or on the wall scraper. The movement of the sensor through the product results in an optimal heat exchange and a representative product temperature.The transmitter is located above the product surface and several infrared diodes transmit the measuring data contact free to the receiver. The transmitter is operated by means of a battery with a life duration of 3 years. The normal measuring range is between approx. – 55 to + 125 degrees Celsius. The standard resolution is 0,125 degrees Celsius. In practice the measuring systems has achieved excellent results. Even product deposits on the sensor unit, i.e. creams, did not affect the transmission of the measuring results.Even on existing mixing units this temperature measuring system can be installed later, it’s instrumentation and control technology can be supplied and fitted individually to suit the specific mixing process.

Development of a new high viscous mixer

In October 2004 the Federal Ministry of Economy and Labour has granted us financial resources for a research project. The operating period of this project is two years and is being processed in co-operation with the German Institute for Food Technology in Quakenbrück. The objective is the development of a new mixer, which enables the processing of difficult and shear sensitive formulas in the high viscous range.This will be processed with a double planetary mixer, where both mixing tools are dependant from each other with respect to revolutions and rotation speed. The requested electric drive is to be developed in connection with a brand new sealing unit, which complies with the special demand in sensitive production fields (i.e. pharmacy, food industry).The heat transmition behaviour is to be optimised by means of electrically heated mixing tools. The project will be closed after completion and testing of a prototype, which indicates an optimised process behaviour, especially for lumpy and shear sensitive products of the food and pharma industry.

Homogeniser with integrated slot adjustment

Already in October 2001 we received the allowance notification from the Federal Ministry of Economy and Technology for a two years research project, which deals with the development of a new mixing and dispersing unit with a product specific energy and shearing record.This project was also accomplished with the German Institute for food technology in Quakenbrück.The project work to characterise the influence of revolutions, direction of rotation, geometry of the shearing zone (rotor and stator) on the emulsifying result and the resulting throughput led to developing an adjustable dispersing unit. A rotor-geometry with only three conveyor elements proved itself during the experimental tests. The applied triangle elements and an optimal emulsifying reaction resulted in a higher conveying capacity. The stator in the dispersing unit was a splitting system with two concentric rings.