The centrifugal extractor is a fast and efficient liquid-liquid extraction (solvent extraction) equipment that uses centrifugal force to achieve liquid-liquid extraction and separation. The equipment can achieve multiple functions such as liquid-liquid mixing, mass transfer, reaction, extraction, washing, and separation.
In order to ensure efficient separation, it has the following requirements for the raw liquid:
1. The two phases are immiscible: This is the basic premise of liquid-liquid extraction.
2. The density difference between the two phases is at least 0.1: A sufficient density difference helps to achieve effective separation through centrifugal force.
3. The separation liquid cannot contain solids: solid particles will interfere with the separation process and reduce the separation efficiency.

However, in the production process of fine chemicals and traditional Chinese medicine extraction, due to the nature of the raw liquid, high-speed stirring of the equipment, and temperature changes, solid precipitation often occurs in the material system, resulting in reduced extraction efficiency, poor separation effect, reduced production volume, and increased equipment maintenance costs.
In actual production, solid generation mainly comes from the following aspects:
1. Fine particles of medicinal materials or flocculent and fibrous precipitation in the concentrate: These particles have low content and small particle size, which are difficult to find. They enter the drum directly with the concentrate. Under the action of centrifugal force, they gradually accumulate and deposit on the inner wall of the drum.
2. The concentrate and the extractant enter the extractor and contact each other. Some components react chemically to produce solids.
3. The concentrate enters the extractor, and the crystals precipitate due to changes in temperature and other conditions.

After the solid is generated, it gradually accumulates on the inner wall of the drum under the action of centrifugal force, causing the inner diameter of the drum to become smaller, destroying the equilibrium interface of the two liquid phases in the drum, and thus causing the following problems:

• Poor separation effect
• Reduced extraction efficiency
• Reduced processing volume
• Abnormal machine vibration

These problems not only affect production efficiency, but also require equipment shutdown, disassembly of the machine, and manual removal of deposited solids on the inner wall of the drum, which increases labor and maintenance costs.
 
The introduction of the online cleaning (CIP) system in the centrifugal extractor can effectively solve these problems.
 
Solution of the online cleaning (CIP) system The centrifugal extractor has introduced an online cleaning (CIP) system, which can effectively remove the deposited solids on the inner wall of the drum without disassembling the drum or adding additional equipment. The CIP online cleaning system is mainly composed of nozzles, hollow shafts, rotary joints, etc. The nozzles are arranged on the hollow shaft at a certain position to ensure that the sprayed cleaning liquid can completely cover the inner wall of the drum.
When the solids are deposited on the inner wall of the drum to a certain extent, the extractor will experience abnormal vibration, poor separation effect, and entrainment of heavy and light phases. At this time, online cleaning can be performed through the following steps:
 
1. Equipment shutdown: Stop the operation of the centrifugal extractor.
2. Connect the cleaning liquid hose: Connect the cleaning liquid inlet hose to the interface of the rotary joint.
3. Select a suitable cleaning liquid: According to the properties of the solid, select a suitable cleaning liquid, such as tap water, alkali solution or solvent.
4. Start cleaning: The cleaning liquid enters the hollow shaft through the rotary joint at a pressure of 0.2~0.4 MPa and is sprayed toward the inner wall of the drum through the nozzle. The arrangement position and spray angle of the nozzle ensure that the cleaning liquid completely covers the inner wall of the drum.
5. Discharge the cleaning liquid: The sprayed cleaning liquid will gradually peel off the solids deposited on the inner wall of the drum and discharge it through the vent valve.

 
Precautions
In order to ensure the best effect of the CIP cleaning system, the following key factors need special attention:

• Cleaning liquid type: Select the appropriate cleaning liquid according to the different solid generation.
• Cleaning liquid pressure: Generally, a pressure of 0.2~0.4 MPa is required.
• Cleaning liquid flow rate: Ensure sufficient flow to cover the entire inner wall of the drum.
• Cleaning time: Determine the appropriate cleaning time according to the degree of solid deposition.
• Nozzle arrangement: Ensure that the position and angle of the nozzle can cover the entire inner wall of the drum.
• Nozzle type: Select the appropriate nozzle type to ensure the cleaning effect.

 
In actual application, after the cleaning work is completed, the cleaning liquid inlet hose needs to be disconnected from the rotary joint to prevent the vibration of the hose from generating eccentric torque on the rotating main shaft of the machine when the centrifugal extractor is working at high speed, causing abnormal rotation of the machine, and in severe cases, bearing damage.
 
The centrifugal extractor effectively solves the problem of solid generation in the feed liquid by introducing an online cleaning (CIP) system, improves the separation effect and extraction efficiency, and reduces the equipment maintenance cost. The system is not only simple in structure and easy to operate, but also does not require additional equipment. It is an ideal choice for solving the problem of solid deposition. Whether in the fields of fine chemicals or traditional Chinese medicine extraction, KMI centrifugal extractors can provide you with efficient and reliable separation solutions.