PENKO Engineering B.V. has developed
a range of solutions and products to calculate and control the accurate mass
flow from all types of containers by means of the loss-in-weight technique,
including the refill procedure.
The
unique way of measuring high speed and high resolution, immediately detects any
changes in the actual flow of mass.
These instruments control negative dosing, regulate mass
flows and totalize the dosed mass. For this purpose the loss in weight (Δm) is
checked and, when required, the related time (Δt) is determined. In the latter case a simple calculation, Δm : Δt, presents
the mass flow.
During the process, the instruments offer a wealth
of information including:
- weighers
contents
- loss in
weight
- dosed mass
- mass flow
In addition to providing this data, the instrument allow for the
controlling of weigher refill functions, switching of dosing devices and
regulating of mass flow.
The speed of the dosing device can be readjusted by continuously
comparing the current mass flow with the pre-set mass flow. During refilling,
so when no loss in weight can be observed, the speed of the dosing device is
regulated in several, empirically established steps, depending of the weighers
contents.
Operating Process
Typically,
a PENKO weighing controller is programmed with a set value for the mass flow
and adjusts the speed of the output feeder in proportion to the amount of the
product. A module recalculates the hoppers output speed and compares the
pre-set mass flow with the actual mass flow. Whilst the hopper slowly empties,
the loss of weight or actual mass flow per unit of time is calculated by the controller
which subsequently adjusts the speed of the output feeder when necessary. This
sequence compensates differences in material flow characteristics due to the
volume of material in the hopper, or changes in material density.
Loss-in-weight
systems are often used for blenders where an additive is continuously fed into
the mix. A typical configuration comprises of a weigher with a regulated
outlet. This can be a screw with variable speed, or a proportional valve. The
sequence starts with the weigher being filled. A recipe value is set for the
gross weight and a second value is set for the pre-set flow rate.
Products:
-
FLEX LIW Controller
- FLEX2100 LIW Controller
- Platforms
- Load cells
Applications:
- dosing of additives
- production of not mixable compositions,
such as salads and nuts
-
in line dosing of liquids