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An industrial centrifuge is a separation machine that uses centrifugal force to separate solids from liquids. A centrifuge exerts a centrifugal force that is thousands of times that of gravity.
This force causes the immediate separation of solids from liquids. And, in the case of immiscible liquids with different densities, it separates the fluids as well.
You can think of an industrial centrifuge is a scaled-up version of a lab centrifuge (test-tube) except at a much bigger scale with a flow-through design.
That means the separated solids and liquid(s) continuously exit the centrifuge.
Industrial centrifuges fall into two main categories: Filtration type and Sedimentation type.
A perforated media allows the fluid to exit the 'screen' bowl in a filtration centrifuge while retaining the solids. The separated liquid collects in the bowl casing and drains out.
A relatively lower rotational speed (lower centrifugal force) is adequate for filtration centrifuges.
They are suitable for separating large amounts of coarse solids from a liquid. An example would be the separation of crystallized sugar from syrup or a chemical precipitate from the supernatant.
There are various mechanisms to collect the separated solids. A description of some of these methods is in the following section.
There are a variety of filtration centrifuges.
A peeler centrifuge has cloth media, which the user 'peels' away with the solids. A basket centrifuge has a perforated 'basket' that retains the separated solids.
Pusher centrifuges have slotted bowls with an articulated pusher arm to 'push' the accumulated solids. A wire mesh 'screens' holds the solids in screening centrifuges.
A sedimentation centrifuge does not use a flow-through or perforated screen or media. This centrifuge uses a solid bowl, which is also known as a 'solid bowl centrifuge.'
The centrifugal force causes the denser solids to collect along the bowl wall. The lighter liquid thus separates from the solids. A liquid pathway allows the separated fluid to exit the bowl.
This 'solid bowl' feature adds an extra benefit to these sedimentation' centrifuge.
The same centrifugal force also causes the differential settling of two immiscible liquids. In this case, the centrifuge separates all three phases, liquid, liquid, and solid. This separator is known as a 3-phase centrifuge.
Industrial centrifuges find applications in a range of processing and manufacturing industries. See our comprehensive list of centrifuge applications.
Chemical industries use centrifuges to produce coarse and refined chemicals. Sanitary centrifuges find a host of pharmaceutical industry applications, from raw ingredients to finished drugs under hygienic manufacturing processes.
Biotechnology-related companies use disc-stack centrifuges for cell harvesting and reactant recovery methods.
The food industry also has extensive uses for centrifuges. For example, the separation of beer from yeast, orange juice from the pulp, milk from milk-fat, wine from must, flavor extraction all use centrifuges.
The comparison of industrial centrifuges with filters or similar media-based separation methods is quite common. These centrifuges offer several over conventional static separation technologies.
The following is a list of some of the main advantages of industrial centrifuges.
Industrial centrifuges process the fluid continuously for extended periods. They don’t require the downtime associated with filter media replacement.
Continuous operation translates into higher production volume, which leads to increased efficiency.
In the case of filtration, as the filter media accumulates the solid contaminants, the flow-through area (pores) reduces, which in turn reduces the flow volume.
The frequent replacement of filter media is necessary to get higher flow volumes, and this cycle continues with varying flow-rates.
On the other hand, an industrial centrifuge uses mechanical separation to separate and eject the solid contaminants. This purging is a continuous process that allows a centrifuge to process without any reduction in flow-rate.
Industrial centrifuges are heavy-duty machines with an expected life expectancy of 30+ years. Unlike filters, which require constant manual servicing (media replacement), centrifuges are self-operating with fully automatic operation.
The automation practically eliminates service-related downtime, which enhances reliability.
Minimize Product Loss:
The flow-through design feature of industrial centrifuges eliminates the need for manual replacement of filtration media.
Therefore, product losses associated with filter or media replacement are not a concern in centrifugation. Minimized product loss leads to higher productivity and profits.
Low Operating Cost:
The only cost of operating an industrial centrifuge is utilities (electricity, water, air). There are no labor or media costs, which are the main costs related to filters.
Based on the above, the cost per gallon of fluid processed with an industrial centrifuge is negligible. This low operating cost helps the centrifuge owners to recuperate the capital cost remarkably sooner than thought.
Industrial centrifuges are one of the most prolific and understated processing equipment. They have applications in almost all processing industries as described above.
If any type of fluid is handled in a specific industry, chances are there is an suitable application for an industrial centrifuge.