Easy-to-transport batch centrifuge
Transportable centrifuge, designed to fit in a container
The production and further processing of oil byproducts necessitates considerable investment in solid-liquid separation systems. When designing a process, a series of practical tests must be conducted with adequate safety levels in place to establish whether this process actually works in practice and whether it delivers the desired results. In order to conduct test runs cost effectively, a German plant manufacturer came up with a transportable centrifuge designed to fit in a container. R. STAHL tailored the switch and control cabinets for this system to the specific requirements of the operating scenario.
Centrifuge designed to fit in a container
The bavarian company Flottweg SE is one of the leading manufacturers of decanters, separators, belt presses and other systems that can be used to separate process media into its solid and liquid components. For its broad customer based in Russia, the company has developed a "try-before-you-buy" centrifuge, which can be shipped out to different operating locations in a 40-foot container. This centrifuge can be set to work in no time at all, allowing the customer to discover for themselves how it performs when it is used to separate different substances. If these trial runs are successful, the customer can choose to switch to a permanent, larger system with full functionality. The try-before-you-buy centrifuge will then be shipped on to the next location.
Its transportable design and specific functional requirements meant that particular conditions had to be imposed on the design of the control equipment used with it, however, particularly in terms of providing the requisite explosion protection. In order to overcome the specific challenges it faced, Flottweg enlisted the services of R. STAHL. The two companies have enjoyed a long-standing, successful partnership, the fruits of which include a number of special solutions for challenging applications. One of the reasons behind the collaboration is R. STAHL's exceptionally broad product and technology portfolio, which covers every kind of explosion protection you care to think of.
Self-contained so customers can get to work without delay
For a system such as this try-before-you-buy centrifuge, engineering the control equipment, power electronics and other components properly requires extensive experience in the field of explosion protection – and building such a system requires the utmost care. One of the crucial limitations to consider when designing this mobile trial system was that it had to be independent of the on-site infrastructure: With a turnkey solution as the goal, the aim was to develop a system that was essentially operational as soon as the power supply was switched on.
This meant that:
- It was important to eliminate the need for the extensive wiring and installation work that would otherwise be required on site in order to supply the system with the requisite auxiliary media.
- The electrical control system had to be an integral part of the overall system, and had to be as compact as possible.
- The production capacity of the system also had to be maximised. In order to achieve this, drives with the appropriate output were required.
- The explosion-protected design of the enclosures had to be able to conduct away the significant amounts of dissipated power.
Ex de double protection
Control equipment and power electronics are housed in a combination of CUBEx enclosures with flameproof enclosure (Ex d) protection. The design also includes connection chamber enclosures with increased safety (Ex e) protection. With IP66 rated protection, these enclosures offer a basic level of protection against the ingress of gases. In addition, the enclosures are designed with Ex d protection, which means that, in the event that a mixture explodes inside them they are able to withstand the pressure generated by the explosion. In an emergency situation, the exterior of what is referred to as the flameproof chamber would therefore remain intact, preventing the explosion from spreading to the surrounding atmosphere and propagating. Ex e protection means that additional precautions against the generation of sparks from electrical or mechanical sources are featured in the connection chambers.
Even critical temperatures will not affect the entire enclosure: R. STAHL fitted the side wings of the control system (which house the high-performance drive components) with external cold plates. The energy lost as heat is conducted onto this adequately enlarged surface via a special feedthrough.
The CUBEx series permits the creation of enclosure configurations with virtually any geometry and dimensions. Up to three mounting levels can be added for equipping the enclosures, allowing each flameproof chamber to be fully utilised. In our in-house powder-coating plant, we can add a surface finish that is specifically tailored to the location in which the cabinet is to be operated. Operating and display elements can be installed directly in the cover if required. Inspection windows can also be added in the cover or side walls to provide an unrestricted view of the wiring inside.
Explosion-protected control unit for mobile centrifuge
- The flexible CUBEx enclosure range, coupled with expert knowledge in combining Ex d and Ex e types of protection, allowed R. STAHL to create the perfect control system for the transportable centrifuge system.
- The powerful built-in components are reliably protected from explosions by the effective dissipation of significant amounts of thermal energy emitted by these components.
- The compact design and close integration of the control unit in the overall system makes it more mobile.
- Because the entire system requires just a single power supply and does not need any special auxiliary media, the try-before-you-buy centrifuge can be moved anywhere and requires minimal set-up – the operator simply has to "plug and play"!