A cryogenic grinder is a device that combines low-temperature freezing with mechanical grinding, used for crushing and homogenizing samples, particularly suitable for processing heat sensitive or high hardness samples. Its working principle is as follows:

Working principle of cryogenic grinder

1. Sample pretreatment

Before grinding, the sample usually needs to be frozen:

Liquid nitrogen freezing: Place the sample in liquid nitrogen for rapid freezing to ensure complete freezing of the sample. Freezing with liquid nitrogen can prevent thermal denaturation of thermosensitive samples during the grinding process.

Mechanical freezing: Some cryogenic grinders have built-in freezing systems that can cool samples to the desired temperature inside the equipment.

2. Selection of grinding media

Grinding medium is an important component of cryogenic grinding process, usually including:

Grinding balls: Grinding balls made of different materials (such as stainless steel, ceramics, tungsten carbide, etc.) are used, and the size and quantity are selected according to the characteristics of the sample and the grinding requirements.

Grinding jar: a container that holds samples and grinding balls, and selects the appropriate grinding jar based on the sample size.

3. Sample loading

Put the frozen sample together with the grinding ball into the grinding jar, ensuring good sealing to prevent moisture or contamination of the sample.

4. Low temperature grinding

Grinding under low temperature conditions, the specific steps are as follows:

Set grinding parameters: Based on the characteristics of the sample and grinding requirements, set parameters such as grinding time, speed, vibration frequency, etc.

Start grinding: After the grinder is started, the grinding ball moves at high speed in the grinding tank through high-speed rotation or vibration, colliding, squeezing, and rubbing with the sample, thereby crushing and homogenizing the sample.

5. Temperature control

Freezing grinders are usually equipped with a temperature control system, which monitors and adjusts the temperature during the grinding process in real time to ensure that the sample is always in a low temperature state and avoid thermal damage to thermosensitive samples during the grinding process.

6. Sample recycling

After the grinding is completed, stop the equipment, open the grinding tank, and take out the ground sample. For samples that require further analysis, appropriate treatments such as dissolution, centrifugation, filtration, etc. can be performed.

Cryogenic grinders are of great significance in scientific research and industrial applications, especially in biomedical, food science, materials science and other fields, providing reliable sample processing methods.