1、 Core principles of cleaning and disinfection

Before carrying out specific operations, three core principles must be kept in mind:

1. Timeliness principle: After each use, preliminary cleaning should be carried out immediately to prevent material from drying and solidifying, especially after handling samples with high sugar, protein, or inorganic salt content.

2. Principle: Cleaning should cover all parts in contact with the material, including visible areas and concealed dead corners. Any residue may become a breeding ground for microorganisms or a source of contamination for the next experiment.

3. Safety principle: Before operation, it is necessary to cut off the power, cool down, and wear appropriate personal protective equipment (such as gloves and goggles). Understand the chemical properties of the cleaned materials and choose compatible cleaning agents.

2、 Standard cleaning procedure (after each experiment)

Step 1: Shutdown and Disassembly

After the experiment is completed, turn off the heating and peristaltic pumps first, and let the fan continue to run for a period of time to cool the system and blow away residual moisture.

After the equipment cools down, disconnect the power supply.

Refer to the equipment manual and carefully disassemble all accessible material components, typically including material tanks, feed tubes, nozzles (atomizers), drying chambers, cyclone separators, and collection bottles (main and tail products).

Step 2: Preliminary rinsing and soaking

Pre rinse the disassembled components with a large amount of warm water (approximately 40-50 ° C) to remove most of the surface residue.

For dried dirt, the components can be soaked in warm water or soaked in a neutral laboratory cleaning solution for 15-30 minutes to soften them.

Step 3: Fine Brushing

Use a specialized soft bristled brush (such as a nylon brush) to carefully scrub the inner walls of components, pipe joints, and all dead corners.

Special attention should be paid to the atomizing nozzle, as its tiny holes are prone to blockage. It should be cleaned with a matching specialized needle or ultra-fine soft brush, and the action should be gentle to avoid damaging the precision structure.

The interior of the drying chamber and cyclone separator can be cleaned with a long handled brush to ensure no visible residue.

Step 4: Final rinsing and drying

After scrubbing all components with cleaning agents, they must be rinsed 2-3 times with purified or deionized water to ensure that there are no residual cleaning agents.

Place the cleaned components on a clean rack and let them air dry naturally in a well ventilated area, or use oil-free, dry compressed air to blow dry. Do not use towels or other wiping tools to avoid introducing fiber pollutants.

3、 Deep cleaning and disinfection process (regular or when changing product lines)

When replacing experimental materials, reusing after long-term disuse, or producing products with microbial limit requirements, deep cleaning and disinfection are required.

1. Deep cleaning:

For stubborn stains such as grease and coke, diluted acid (such as 1-2% nitric acid solution) or alkali (such as 1-2% sodium hydroxide solution) can be used for soaking and scrubbing. Before use, it is necessary to confirm the compatibility between the chemical and equipment materials, and operate in a fume hood. After soaking, rinse until neutral.

2. Disinfection method:

Damp heat disinfection: For high temperature resistant glass and stainless steel components, a high-pressure steam sterilizer at 121 ° C for 15-20 minutes can be used for sterilization. This is a reliable and residue free method.

Chemical disinfection: For components that are not resistant to high temperatures (such as certain plastic collection bottles), 75% ethanol, hydrogen peroxide (such as 3%), or specialized quaternary ammonium salt disinfectants can be used for soaking or wiping. Disinfectants need to cover all surfaces and maintain sufficient contact time (usually 15-30 minutes), after which they must be rinsed clean with sterile or purified water to prevent disinfectant contamination of subsequent samples.

In situ disinfection: Some models are equipped with in-situ cleaning (CIP) function, which can disinfect the entire material path by circulating disinfectant (such as peracetic acid) through the system program, with convenient operation and uniform effect.

4、 Key precautions

Nebulizer maintenance: Ultrasonic cleaning is an efficient method for cleaning small holes in atomizers. Regularly check for wear and replace in a timely manner.

Sealing ring inspection: During the cleaning process, check whether the sealing rings of each interface are aging or deformed. If they are damaged, replace them immediately to ensure the airtightness of the system.

Record: Establish a cleaning and disinfection record form, recording the time, method, reagents used, and operators for each operation, for easy traceability and quality control.