A centrifuge is a mechanical device that is used to generate centrifugal force. The device is normally spun radially on a fixed central axis and forces are generated to act on the contents of the device. This action can generate Centrifugal force, Centripetal Force or both simultaneously. The dominant force generated is determined by various factors including the direction of rotation among others.
The intensity of centrifugal force is measured by how it compares to the force of gravity and it is determined by the speed of rotation. High-speed centrifuges can generate centrifugal forces that are more than 2,000 times the force of gravity.
Centrifuges can be categorized in several different ways such as based on the speed of rotation, the designated function and the size among others. In this article, we will look at one of the most basic centrifuge classification based on the mode of operation. In this format, the centrifuges can be divided into three categories, they are, Manual, Automatic and Semi-Automatic Centrifuges.
These are by far the cheapest centrifuges money can buy and also the easiest to make. These systems are quite affordable because they rely more on human action than technology. Although you may save a lot on the buying price of a manual centrifuge, these systems require a lot of time and energy to operate.
It is advisable to only use a manual centrifuge if the designated task does not need to be carried out continuously. For maintenance of such a system, you will need to take out and clean or replace the filtration bag whenever necessary and regularly and clean the drum by hand.
This type of centrifuge works much like the manual system but only adds an automatic cleaning element to the process. The cleaning action is not sensed automatically so there still needs to be some action from the user. The system, however, makes the work a lot easier for the operator allowing him to focus on the feedstock and output rather than the continuous maintenance of the centrifuge.
Although automatic centrifuges are more expensive to purchase, they are the cheapest to operate and maintain. Large volumes of product can be cleaned through the centrifuge using only one operator because the system is self-cleaning.
The system has sensors that detect when the waste collection bowl is full and automatically sends a signal to clean out the walls and dispose of the waste. This makes it possible to run continuous operations and handle heavy workloads efficiently.
Due to their high efficiency and ability to run continuously for long periods of time, automatic centrifuges are suitable for running processes that require high and ultrahigh speed centrifuges.
High-speed centrifugal processes are operated at speeds of between 21,000 rpm and 30,000 rpm achieving a relative centrifugal field of about 120,000 times the force of gravity.At these speeds, it is necessary to have cooling or refrigeration components to manage the heat generated by the centrifuge moving parts. In some cases, the operation needs to be carried out in a vacuum. The high-speed centrifuges are used in medical labs to separate cells and isolate viruses.
Ultracentrifuges are operated at speeds above 30,000 rpm and can generate forces that are more than 600,000 times the force of gravity; at such high speeds, refrigeration and incorporation of vacuum systems are unavoidable. Ultracentrifuges are used in advanced laboratories to isolate membrane components such as DNA, RNA and the endoplasmic reticulum as well as ribosomes and endosomes.
Centrifuges have a wide range of applications and it is important to be clear about the type and load of work you aim to accomplish with the centrifuge. If you have a small irregular workload, it would be a waste to invest in an automatic system likewise if you have a continuous workload, the manual systems will wear you out. Take time to research the types and uses of centrifuges that match your task before you make a final decision. Also if you think your workload will start small and increase with time, try buying a semiautomatic system then upgrade to a fully automatic one when your business is big enough to handle it.