When a customer-specific development is needed, reliable DC motors and controllers are a good basis. In a flameproof casing, the duo consisting of motor and Motion Controller can perform tasks even in potentially explosive atmospheres. A masterpiece in terms of development that proves itself not least of all on critical ground – and that's what systems in chemical engineering are.
As with so many good projects, it began with the cooperation of competent partners. Here, the mechatronic experts from the Mattke company in Freiburg and the drive technology engineers from FAULHABER make a good team. Last but not least, good and solid drive technology from Schönaich serves as the ignition spark for creative ideas.
The task of the specialists from Freiburg was to use a brushless FAULHABER motor with Hall sensors and a Motion Controller with RS232 interface to construct an explosion-proof system. The fact that Mattke is well versed in the world of movement is apparent in motto of the firm's 50th anniversary: "Mattke moves", to be celebrated later in 2015.
The development goal of the collaboration between Mattke and FAULHABER was to create a suitable drive for a micro annular gear pump (mzr® pump). This is where the third partner came into play, the pump specialist HNP Mikrosysteme from Schwerin. The design of the pump was already specified, as the pumps are successfully used in numerous customer systems. The possibility of obtaining an ATEX motor with integrated control would allow additional customer requests to be satisfied that could not previously be met. There was a discussion early on with Faulhaber and Mattke about desires regarding function and design; the two motor specialists realized the technical implementation. Just finished and sufficiently tested, the motor is already used as the drive of a hermetic inert micro annular gear pump in a drinking water treatment plant in a chemical engineering application.
Our partner for motors and controllers"
What is special about the pump drive is the integrated Motion Controller, which is located with the motor in an explosion-proof housing", says Werner Böhringer. As director of Mattke AG, he is responsible for this project. Previously, DC motors were combined in a flameproof casing with micro annular gear pumps.
Today, integration is called for. "To make the pumps efficient and more controllable and to reduce the installation space, HNP Mikrosysteme uses micro annular gear pumps for both: brushless motors and Motion Controllers from our partner FAULHABER", declares Böhringer.
The Mattke engineers developed a flameproof, enclosed housing for the drive pair "that did not exist previously on the market, even though it is exceptionally effective", notes Böhringer. By enclosing the Motion Controller in a capsule together with the motor, cumbersome precautions for the sensitive electronics of the servo controller can be dispensed with. In addition, signal losses that arise due to long supply lines if the electronics are placed outside of the potentially explosive area are avoided.
"The integration of all components in a flameproof casing makes life easier for the pump manufacturer and his customers", finds Werner Böhringer, making reference to the certification without which nothing happens in most of the places where the pumps are used. It is the reward for good development work. "By enclosing the electronics, we were able to clear the hurdle for ATEX certification for motor plus servo controller.
Integration of the electronics – a logical development step
A glance at the requirements profile of the pump shows the high demands on this technology. This is due to the fact the micro annular gear pumps deliver and dose low-to-medium viscosity media with high precision. The profile of such pumps therefore includes attributes such as low pulsation, low dead volume, low shear stress, long service life, low weight and a compact design. And because micro annular gear pumps seem destined for applications in potentially explosive atmospheres, the servo-controlled motors with ATEX certification are a must today at HNP Mikrosysteme. Serving as the basis of this Mattke solution are the brushless FAULHABER 3268 ... BX4 series DC-motor with Hall sensors and the FAULHABER MCBL 3003 series Motion Controller, which can be controlled via CANopen or via the RS232 interface.
When used for treating water
In a customer project for water treatment, the mzr-7259X2S Ex pump delivers the so-called bleaching lye, a concentrated, aqueous solution of NaOCl. Bleaching lye acts, for example, as a selective oxidant or disinfectant in water treatment processes.
A word on the process-engineering performance data: the micro annular gear pump of the hermetic inert series from HNP Mikrosysteme enables flow rates from 0.048 ml/min to 240 ml/min as well as differential pressures from 0 to 10 bar.
"The pump is driven by Mattke motor EXR-32.24-MC3-L10, which is based on a solution from FAULHABER", explains Dr. Carsten Damerau from HNP Mikrosysteme. "It is the special characteristics of pump and drive as well as the excellent interplay that enable use for extremely demanding delivery tasks, such as those required in the treatment of drink ing water."