Sealing of centrifuges

Whether the centrifuge used in the medical and pharmaceutical related industries requires a non-sterile environment or a sterile environment, high requirements are placed on the environment during its use. Under high-level environmental requirements, such as in sterile workshops, there are For workshops of 10,000-level and 100,000-level, good airtight performance can keep the outside and the inside of the machine effectively isolated. The solid, liquid and gas phase in the inner cavity of the centrifuge shall not be cross-contaminated with the operator and the external environment. Generally speaking, the user should inform the centrifuge manufacturer when ordering, and put forward the sealing requirements. Manufacturers should improve the design of the airtight performance of the centrifuge, and fully reflect it during manufacture, generally focusing on the following parts:

Sealing of the cover: Because the cover is reversible, there should be reliable sealing measures on the joint surface of the casing. If the sealing structure or material fails to prevent corrosion, it may cause leakage of liquid and gas phase, causing harm to the environment and personnel.

The anti-corrosion performance of the sealing groove structure and the sealing strip should be fully considered in the design and selection of its sealing performance and reliability.

There should also be reliable sealing measures for the installation interfaces of additional devices such as feeding pipes, washing pipes, and observation mirrors.

Sealing of the bearing position: For the sealing of the spindle nut and the bearing position, the previous traditional models have relatively simple sealing measures in this regard, and can only achieve relative sealing. For example, the main shaft nut part, the joint surface between the main shaft nut and the drum, is generally not provided with a sealing ring. During the operation of the centrifuge, the liquid phase and gas phase infiltrate, which will corrode the main shaft cone surface and even penetrate into the bearing, causing damage to the bearing and affecting the normal use of the machine. The upper bearing cover is generally provided with a skeleton seal and other structures, but a part between the upper bearing cover and the cone hole of the drum is exposed, and the gas phase in the inner cavity of the centrifuge may corrode the exposed surface of the main shaft. For centrifuges used in the pharmaceutical industry, most of the materials separated are organic solvents or media such as acids, alkalis, and salts. Therefore, when ordering equipment, the sealing requirements of these parts should be fully considered, and dynamic sealing or static sealing structure should be set up to achieve sealing requirements.

Sealing of the working area of the transmission belt: The transmission belt of the traditional centrifuge is open, but a protective cover is set at the motor end, mainly from a safety point of view, to improve the safety of its use, but the dust generated by friction will pollute the environment. If it is not controlled, it is not feasible to use it in a clean area. Therefore, the working area of the transmission belt must be sealed to prevent the leakage of friction dust.

Other parts (interface parts such as liquid outlet pipe, feeding pipe, hopper, etc.): For the external pipes of the centrifuge, such as the feeding pipe, washing pipe, cleaning pipe and other pipes, the flange installation method is generally used to ensure the The sealing performance of the interface, for some occasions with high requirements on cleanliness, the interface should use a sanitary quick-open interface device to facilitate cleaning.