When chemical resistance, robustness and durability matter! Then the plastic magnetic-drive chemical centrifugal pump of the MCH series is the best choice!
Pumps used
- MCH series – magnetic-drive chemical pump for industrial applications
As an innovative chemical group with numerous international locations, Zschimmer & Schwarz is a global player with customers all over the world.
In Lahnstein the company operates a chemicals wholesale business in which a wide variety of chemicals are delivered daily in tanker trucks and then have to be filled into containers and other delivery vehicles.
The chemical storage facility, consisting of about 30 large tanks, was completely equipped in 1994 with MARCH magnetic-drive chemical pumps of the MCH series. The plant builder responsible was the globally active KUSTAN GmbH from Gelsenkirchen.
The demanding task was initially to standardise all magnetic pumps as far as possible in order to minimise the stock of spare parts and maintenance costs and thus reduce operating costs to a minimum. A competitive advantage here is the fact that all MARCH magnetic-drive chemical centrifugal pumps are completely maintenance-free, and that the pumps were protected against damage from overload, dry running and operating errors by an external electronic power monitor.
Tanker emptying as well as filling, down to small containers, was to be realised with only one pump type in each case. This meant that all pumps had to be usable for a performance range from 1,000 l/h up to 30 m³/h in order to keep filling times, and thus the standing times of the delivery vehicles, as short as possible.
The pumps also had to be designed for the widest range of chemical properties, such as density and viscosity, but above all the chemical resistance to the different media.
In Lahnstein, almost the entire range of different chemicals is filled, such as phosphoric acid, nitric acid, sulphuric acid, caustic soda, hydrochloric acid, caustic potash, etc.
The pump casings of the MCH chemical centrifugal pump are machined from solid material and are therefore extremely robust for industrial purposes compared with typical injection-moulded casings. In addition to the use of resistant pump materials such as PVDF and polypropylene, it was decided to use exclusively SiC as the uniform pump shafts and plain bearings, which is chemically resistant to all media to be pumped.
The different densities and viscosities of the media were taken into account by using different impeller sizes, so that here too only one motor frame size could be used uniformly for all pumps.
All pumps were equipped with an automatic pump monitor of the type MARCH MASTER CONTROL (MMC), so that the pumps were switched off automatically after the emptying or filling process had ended to avoid dry running of the pumps, which is very important for increasing service life. For residual emptying, the MMC can also be set with an overrun time, during which the pump continues to run for a few seconds at reduced speed until the tank is completely empty.
Small-container filling in Lahnstein was realised with a clever frequency converter bypass system control, in which excess medium was routed back into the supply tank after the container was filled.
To this day, i.e. even after more than 30 years of uninterrupted operation, in stop-and-go operation of the tank facility in Lahnstein, only 3 replacement pumps and 6 replacement plain bearings have been supplied.
This confirms the durability and robustness of the chemical pumps of the MCH series from MARCH PUMPEN.
