Today marks the continuation of BaseVac’s series on understanding the difference between Dental Vacuum systems and which one is best for your clinic. Thus far, we have covered some dental vacuum definitions, in hopes of giving Dental Professionals enough background on vacuum that it will assist in understanding the rest of this series.
Today, we will be highlighting the different vacuum pump types you will experience in a Dental Clinic.
Vacuum Categories
If it is your goal to replace an existing vacuum system, it is always important to know what type of pump is being replaced. In dental, vacuum pumps fall into one of two categories; high flow and low flow.
High Flow
· Regenerative (Most Popular High Flow) – Regenerative pumps are one of the least expensive and simplest motors to produce on the market. In a regenerative motor, an impeller is incased with a high tolerance gapping. These systems are dry-vacuums, so they take the air in through the inlet; as the air enters the channel, the rotating impeller imparts velocity to the gas in the direction of rotation. Centrifugal force in the impeller blades accelerates the air outward, increasing the pressure. Every rotation adds kinetic energy, resulting in a further increase of pressure along the side channel. The side channel narrows at the rotor, sweeping the gas off the impeller blades and discharging it through the outlet silencer where it exits the pump.
· Centrifugal - Centrifugal pumps are hydraulically operated machines characterized by their ability to transmit energy to fluids (in particular to liquids) through the work of a field of centrifugal forces.
Low Flow
· Wet-ring (Most Popular Low Flow) – Wet-ring or liquid-ring pumps are quickly becoming antiquated technology, as it consumes high volumes of water to function. Liquid ring vacuum pumps are similar to a rotary vane pump, with the difference being liquid-ring pumps use 4L of water/min/pump to generate vacuum. The vanes of the pump churn, creating a seal of water, which compresses the air, creating vacuum.
· Rotary Vane (BaseVac) - A rotary vane pump is a positive-displacement pump that consists of vanes mounted to a rotor that rotates inside a cavity. BaseVac has six free-floating vanes that use the rotation of an off-set rotor to shoot out the vanes against the rotor housing, compressing the air, which creates the vacuum. It is the nature of our oil-free vanes that allow our systems to achieve higher than average suction (25” of Hg).
· Hook & Claw - A claw pump consists of two rotors, designed to rotate in the opposite direction. As the claw rotates, it sucks air into the compression chamber. The gas is pre-compressed within the compressing chamber and is then discharged.
· Ejector - A type of vacuum pump, which produces vacuum by means of the Venturi effect. A Venturi vacuum is created by a pump with compressed air running through it, yet the pump has no moving parts. Compressed air runs through the initial chamber, then a smaller portal that opens into another larger chamber, which is like the first one.
When we consider the demand in the clinic based on airflow through open holes and working holes, we get an idea of how much airflow, Cubic Feet per Minute (CFM), the vacuum pump really needs to move. The Canadian and American Dental Associations state that 5”of Hg is the minimum required vacuum energy required to lift a piece of amalgam. The question now is, at what flow is that energy level required? It is at this point when we have to consider choosing a High-flow vacuum or a Low-flow vacuum.
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Many factors in a Dental Clinic determines if you should choose a High-Flow vacuum or a Low-Flow vacuum. Our next segment will be discussing the factors you should consider when looking at a new suction unit for a Dental Practice.