Our customer
Knauf PFT GmbH & Co. KG is an internationally renowned manufacturer of construction machinery technology and produces machines for the construction industry for conveying, mixing and pumping plaster, mortar and screeds. The product portfolio includes, among others, conveying and mixing pumps, pneumatic conveying systems and horizontal continuous mixers.
The PFT FErro machine combination is a continuously operating mixing and conveying pump for processing flowing screed. It conveys all machine-compatible screeds from silos and containers fully automatically. After the addition of water in the mixing tube, the material is fed into the feed hopper of the delivery pump via a horizontal mixer equipped with its own drive and is conveyed to the processing point at a rate of up to 100l/min*.
Challenge
To guarantee a constant and highest possible quality of the flowing screed, the screed powder is mixed with water in a defined ratio. Maintaining the specific viscosity is a basic requirement for a durable and safe screed. However, disturbing influences on the mixing process can result in the form of a fluctuating water supply, changing environmental influences (air humidity, temperature) or a different composition of the dry material.
In order to guarantee a consistently high quality of the mixing process, a suitable sensor system is required that allows conclusions to be drawn about the viscosity of the mix. However, this must be able to withstand the tough challenges of construction site use, such as daily cleaning work, heavy soiling due to dried material or changing weather conditions outdoors.
Solution
The viscosity of the mixed material is directly related to the torque required at the mixing screw. If the water content is too high, the torque decreases, while the power requirement increases if the water content is low. This correlation is used to adjust the feed rate or water quantity in a more controlled manner and to enable continuous monitoring of the process.
"plug & play": plug-in adapter with integrated torque sensor coreIN
A plug-in adapter with the integrated torque sensor has been coreIN which can be integrated into existing drives. The sensor component is characterized by its protected and robust design and thus resists contamination or mechanical effects. Due to the functional design, the sensor can be installed "plug & play" into the drive train within a few minutes.
The screed mixing unit is surrounded by a metallic protective device. In the dry area of the mixer, a small opening is made for transmitting the Bluetooth signals to the gateway coreGATE is provided. This is located in the adjacent control cabinet and converts the torque there into an analog signal, which is transmitted directly to the cloud with other data from the plant.
