Hygienic and free from wear – New contact-free
flow measurement with Lutz eccentric screw pumps B70V
For the eccentric screw pumps of series B70V-D a lifting device with integrated impulse sensor for indirect flow measurement was developed. The contact-free mode of measurement is very interesting for hygienic applications in the food-, pharmaceutical- and cosmetics industry, as well as for industrial applications with viscous, adhesive and solid containing liquids. Experience has shown that conventional volumetric flow meters quickly come to their limit, while other measuring methods are often very complex and/or are not suitable for mobile use.
The contact-free mode of measurement with impulse sensor is a reliable and economic option. The measurement is made hygienically and free from wear without direct contact with the liquid being pumped.
According to the rotating positive displacement principle, the characteristic curve of an eccentric screw type pump is nearly linear. It is therefore possible to determine the pumped liquid amount by means of the number of shaft rotations. With a difference of +/- 1 impulse per measuring process, the reproduction accuracy is very high as long as the system factors such as viscosity, pressure, hose diameter, temperature and flow are steady. Depending on the demand of precision and abrasiveness of the medium, the calibration factor must be temporarily adjusted to the wear of the pump hydraulic system. When using a motor with integrated frequency converter, the flow capacity of the pump can be individually adjusted to the respective application conditions.
An impulse transmitter transfers magnetic impulses of the rotating motor shaft contact-free to the impulse sensor. The measured impulses are evaluated in the Lutz operating unit BE10 and are provided on the display by means of the pre-determined calibration factor as transferred flow quantity. By using the relay module RM10 and respective connecting cables, the system also can be used as filling station with preselected quantity (batch function) – like known from the modular Lutz flow meters. The Reed impulses can be optionally also evaluated with evaluation units provided by the customer and external control.
Features and advantages
Hygienic aspects and specific demands were considered on construction by which the system partially differs from comparable solutions:
• Compact and easy to handle unit for maximum mobility
• All live-/data elements on the motor-/lifting-device unit
• Pump tube can be detached from motor-/lifting-device by means of a quick-action coupling
• Pump tube without electronic components enables a thorough cleaning and disinfection also by water jets or in cleaning machines
• Easy handling and control with the Lutz operating unit with touch screen display and menu-navigation in plain text
• Can be combined with relay module RM10 and other modules of the Lutz flow meter programme
• Lutz eccentric screw pumps B70V-D which are currently used can be economically retrofitted
With this innovative and user-oriented solution concept, Lutz has again considerably extended its flow meter programme for the transfer of viscous and hygienic media.