Favourite of dentists

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.

Inner quiet

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.

Fully adapted

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.

Stream­lined high-perfor­mance

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