Page 44 - EngineerIT May 2022

TECHNOLOGY, INNOVATION, NEW PRODUCTS AND PEOPLE

Magnetic-inductive flow meter for safe chemical

treatment of wastewater

OBOLD was tasked to provide The device operates according to the principle of electromagnetic measurement -
a solution for the problem of Faraday’s Law of magnetic induction - where a voltage is induced in a conductor moving
Kphosphate precipitation in through a magnetic field. The electrically conductive measuring agent acts as the moved
wastewater treatment plants. By adding conductor. The voltage induced in the measuring agent is proportional to the flow
Iron (III) Chloride (FeCl3) into the aeration velocity and is therefore a value for the volumetric flow. The flow rate is calculated on the
basin, the phosphates dissolved in excess cross-sectional area of the pipe. The measurement is dependent on the process liquid
wastewater are chemically mixed with and its material properties such as density, viscosity and temperature. The device may be
sludge flocculants and transferred with equipped with a switch, frequency or analogue output.
sludge to the sludge treatment stage. This With an analogue 4-20 mA signal (or optional pulse output) the MIK continuously
process reduces phosphate concentration communicates the measured values to the users’ process control system, so that it
in waterways and minimises the allows for immediate response to the latest process conditions. This results in increased
potential for abnormal algae growth efficiencies and cost savings in the amount of Iron Chloride required to achieve
and its detrimental effect on the aquatic phosphate removal, as well as the vitally important environmental protection component.
ecosystem. Because an overdose of Iron Areas of application are flow monitoring, flow measuring, dosing and counting
(III) Chloride results in massively polluted for machine building, chemical, paper industry, automobile, cement industries and
water - toxic to humans as well as the laboratories.
environment, a completely dependable
method of process monitoring had to be For more information Contact Instrotech on +010 595 1831 or log onto the product
developed. information at https://bit.ly/35UZvDd
The ideal would be a continuous flow
measurement of the dosing chemical with
a direct data connection to the process
control system which would guarantee
maximum safety and avoid possible errors
which would only be discovered during
sample taking when it´s too late and the
damage done.
The solution is the KOBOLD MIK
magnetic-inductive flow meter, an
optimal and economical solution for a
safe dosage of Iron (III) Chloride, and
specifically developed for this application.
The unit has already proven itself very
successfully in service, specifically for
electric conductivity liquids, acids and
caustic solutions, drinking, cooling and
wastewater, groundwater, raw water and
aggressive or salty solutions. However it is
unsuitable for oil (lacks conductivity).
The MIK is housed in polyvinylidene
fluoride (PVDF) and the electrodes in
contact with the medium are made of
tantalum. Both materials have proven to
be chemically resistant. With the directly
mounted transmitter within stainless
steel housing, this device forms a very
compact and robust unit, ideal for fitting
inside cramped control cabinets. It allows
detection of very small dosage amounts
from 10 mL/min.

EngineerIT | May 2022 | 42