Sealing Systems
   

Most sizes and models of Flottweg centrifuges are available in a variety of rotor and housing seal designs for the following operating conditions :

> atmospheric
> vapor-tight
> gas-tight
> pressure-tight

The centrifuges can also be adapted for operating in closed-loop systems.

3. Gas-tight centrifuges allow safe operation with toxic, corrosive or flammable media by applying inert purge gas to rotor seals and by inertizing the process chamber and centrifuge housing. Slight positive or negative pressures can be maintained in the process area by regulating the purge gas supply. Special sealing elements minimize the seal gas consumption.

4. Pressure-tight centrifuges enable operation at elevated over pressure or under vacuum depending on the hazardous nature of the product. Typically, these machines are provided with liquid buffered mechanical seals for isolating the rotating centrifuge components from the atmosphere.

1. Atmospheric centrifuges are the standard version and the most commonly used for applications where there is no harm from products or vapors being released to the environment and where it is not necessary to isolate the centrifuge bowl from the surrounding atmosphere.

2. Vapor-tight versions of Flottweg centrifuges are the right choice in cases where substances emitted from the process could pollute the environment or if contact of the product with ambient air is undesirabel. Additional seals on rotor shafts and housing provide the necessary tightness. Emissions can be completely averted when purge gas/air is applied to seals or the centrifuge housings are vented.

 

 

For special applications, Flottweg has developed hermetically sealed pressure tight centrifuges (patented), which utilize a unique hydraulic drive without any shaft journals.

 

 

 

 

 

Seal Systems

  1. Atmospheric
  2. Vapor-tight
  3. Gas-tight
  4. Pressure-tight

Inserting a scroll bearing seal ring (mechanical seal)

 

  
Inertizing

Centrifuges processing hazardous (flammable or toxic) compounds must be of a gastight design and/or operated under an inert gas blanket. Inertizing may also be used when oxidation of products has to be prevented.

 

1. Hazardous Materials

Centrifuges used in applications involving flammable and/or toxic substance from chemical or pharmaceutical industries, solvent extraction processes or oil sludge treatment/recycling must be both gas tight and inertizable.

 

 

Environmental and/or safety regulations in many countries govern the requirements for operating process systems with hazardous materials. Depending on the degree of the potential hazard, both an inertizing and a seal monitoring system may have to be utilized.

 

1.1 Low Risk Applications

In the low risk category, a system monitoring the flow of inert gas to the individual seal areas (three in a solid bowl centrifuge) is the most commonly applied solution. The system ensures a constant flow rate above a pre-set limit.

  Inertgas monitoring unit  

1.2 High Risk Applications

For high risk applications, the inertizing system must be capable of monitoring not just the inert gas flow rate but also that a minimum pressure differential is maintained between the various seal points and the centrifuge housing. This ensures that inert gas flows in both directions, into the centrifuge and into the housing and towards the atmosphere, thus guaranteeing seal integrity.

The gas purging of labyrinth seals on gastight machines has the added benefit of extending the service life of the seal assembly.

2. Materials Susceptible to Oxidation

In order to prevent product from oxidation during processing the use of gastight centrifuges supplemented By inertizing systems as described, is recommended. Frequently, however, it is sufficient to use centrifuges in atmospheric design with rotor seals suitable to connect to a vacuum systems have been developed for applications in the food industry.

Differential Speed Control and Overload Protection | Remote Scroll Speed Adjustment | Sealing Systems and Inertizing |

Lubrication and Wear Protection | Centrifuge Monitoring