Many people still have amalgam fillings in their teeth. However, this filling material contains mercury and is not allowed to enter the wastewater stream. Therefore, the CAS 1 Combi-Separator from Dürr Dental AG has become the absolute favourite of dentists.
The double-stage system combines separation and amalgam separation. Through two hoses, the fluids from the mouth suction and the spittoon bowl reach the combi-separator, which separates the secretions from the air using a centrifuge and removes the mercury-containing amalgam. This is integrated directly into the treatment chair. Unlike “wet” suction, only air is removed in this “dry” suction. Therefore, long hoses through which the highly infectious medium flows to a central separation unit are a thing of the past.
Most importantly, the patient hardly notices. In addition to the drive, this is ensured by a special sound dampening system in the housing. This is based on an EC external rotor motor of the VARIODRIVE Compact family with integrated electronics from ebm-papst. “An important criterion in selecting the drive is high running smoothness. Noise and heat should be kept to a minimum so as not to cause additional irritation to patients in dental practices,” Nonnenmacher emphasises. He was the Dürr project manager in charge of developing the combi-separator.
Two of the unit’s features ensure the quiet performance that is needed: the centrifuges, which are injection-moulded with minimal tolerances, and the drive that is designed for running smoothness. However, the drive must also be highly compact, as only a small amount of room is available for the combi-separator in the treatment chair. The ebm-papst drive meets this requirement ideally — one of the reasons being that the design engineers have equipped it with a longer shaft. “Only this way was it possible to implement the combined separation,” explains Nonnenmacher.
The motor incorporates even more customer-specific changes. Instead of ferrite magnets, the drive for the combi-separator uses plastic-enclosed magnets. “This provides the advantage that the plastic-enclosed magnets were quiter,” Nonnenmacher elaborates. The drives communicate with the electronics of the treatment unit via an individually adapted interface: “This allows us to display levels or various operating states,” he emphasises. Because the medium extracted by suction is extremely aggressive and can react with untreated aluminium, the engineers from St. Georgen, in collaboration with the customer, have protected the motor flange with a resistant coating.
The design is not the only feature that makes the combi-separator from Dürr Dental a streamlined solution. Its high efficiency is equally valuable. “Only a limited amount of energy is available at the treatment chair. Therefore, the energy demand is an important consideration in selecting the suitable drive,” project manager Nonnenmacher emphasises.
Here, the numbers add up: “Compared to the previous motor, we were able to attain savings of over 20 percent.” This does not mean any sacrifice of performance. The Combi-Separator CAS1 attains a separation rate of some 98 percent, setting the clear reference in this market and providing reliable protection for our environment.
The VARIODRIVE family
The VARIODRIVE and the VARIODRIVE Compact variant originate from basic elements of DC fans. Because EC drives meet even the stringent requirements of medical technology, they are used in the Dürr Dental CAS 1 Combi-Separator with amalgam separation and the CA 1 Amalgam Separator units.
The outstanding features of these drives:
• 1 and 3-phase external rotor motors in 5 sizes
• High torque stability
• Low vibration
• Low-noise operation
• High efficiency
• Compact design
• Highly functional with integrated operating electronics
• Higher torque in conjunction with gearmotors of different shapes and sizes