We develop, design and fabricate filtration systems for solid/liquid separation in the processing industries as well as Vibratory Mixers and Single-Use Technologies.
The FUNDAMIX® is a well established mixing technology for products which require mixing at low shear forces, which is typically the case in the biotech environment. While cGMP practices intend to control production processes to guarantee quality of products, it means that the mixing quality of an agitated vessel needs to be monitored to assure compliance.
Vibratory action on a mixing plate produces a vertical flow of the fluid. The displacement volume is basically a function of frequency x amplitude. When the drive unit is connected straight to the power supply the oscillating frequency is equal to twice the grid frequency, i.e. either 2x50Hz = 100Hz or 2x60Hz = 120Hz. In case a frequency converter is applied its frequency can be monitored on the device and is a fixed value.
For the amplitude, however, it is a different issue. It depends on many other influencing factors, such as weight of mixing device, fluid density and viscosity or size and shape of mixing plate. This leaves no other option but measure the actual physical displacement of the plate.
Traditionally, amplitude is visually measured with the help of a self- adhesive strip placed on the shaft of the mixer which oscillates along with the mixing plate. On the strip there are two lines forming an arrow. When the device oscillates the arrow appears as two arrows forming an intersection point at which the actual amplitude can be gauged. Although it is a quick and dirty means to measure amplitude it is not easy to get the reading right, as it leaves room for interpretation with each person seeing something else.
Electronic measurement (VM-021):
Later an electronic instrument was developed which consists of a piezo sensor fixed on the shaft of the mixer. The acceleration measured by the piezo is a linear function with respect to amplitude and with some conversion it gives an analog signal which can be used to monitor amplitude and control the drive unit. As the instrument interprets the amplitude based on acceleration data it needs to be calibrated for each FUNDAMIX® separately. Additionally, the sensor is mounted on the shaft and it cannot be easily transferred from one unit to the other. It is usually applied as a fixed installation.
Hand-held laser measurement:
As an alternative to the above instruments we have developed an optical laser sensor, the amplitude monitor. It measures the distance to an oscillating plate fixed on the shaft of the mixer every 1.5 ms. These values are algorithmically converted into an analog reading shown on an integrated display. As we are measuring an absolute distance there is no requirement for additional calibration. This allows the instrument to be applied to all FUNDAMIX® agitators equally, irrespective to other influencing factors such as frequency. As the sensor is not fixed to the vibratory part of the equipment it can be applied as a hand-held battery-operated device to be easily carried around. This marks a new generation of amplitude monitoring instruments and we are proud to offer this to our clients.
Use Filters manually, for improved experience and consistent quality it is recommended to run the filtration package automatically. The filtration is a batch operation and hence the operating sequence runs through a number of distinct process steps, such as Filling, Prefiltration, Heel Volume Filtration and Back-flushing. Various process parameters, such as pressures, flow or turbidity can be measured and logged. These can give valuable input to understand the performance of the filtration package, compare individual filtration batches and optimize the protocols.
To simplify installation and operation, the compact control panel not only houses the PLC but also the custom made SU valves, solenoid valves and air filter regulator for the instrument air supply. Pump, agitator, instruments and instrument air are connected and the flexible single use tubing is easily attached to the valves.
The FundaStep Controller comes in two sizes:
While both controllers provide a total of 6 SU valves and 2 solenoid valves which is more than enough to operate the complete system, the larger housing allows for additional space to install custom instruments which can be attached to an additional DIN rail inside the box. Both housings have the same compact foot print.
The process is visualized on an iPad which connects to the controller via Bluetooth and can be placed anywhere within reach of signal. Valve positions, steps, timers and instrument values are all shown on the high resolution touch screen which allows for complete operator control of the sequence to run in various operating modes: