1、 Preparation before operation
1. Equipment inspection
Confirm that there are no leaks or damages in the heating system, cooling system, and pumping device, and check whether the safety valve, pressure gauge, and thermometer are sensitive and reliable.
Check water level and quality: If the equipment relies on external water supply, ensure that the water quality meets the requirements (chlorine content<50mg/L) to avoid scaling and affecting heat exchange efficiency.
2. Cleaning and disinfection
Start the automatic cleaning system (CIP) and perform water washing → alkaline washing (2% NaOH solution, 80 ℃ circulation for 30 minutes) → water washing → acid washing (2% HNO 3 solution, 80 ℃ circulation for 30 minutes) → final water washing to ensure no chemical residues.
Pipelines and containers that come into direct contact with materials must be thoroughly disinfected to prevent cross contamination.
3. Preheating and parameter setting
Preheat to the target temperature (usually 135-150 ℃) by powering on, and observe the stability of the instrument during the heating period.
Set key parameters: sterilization temperature (determined by material characteristics, such as commonly used 135-150 ℃ for dairy products), holding time (4-6 seconds), system pressure (adjusted according to temperature, maintaining liquid state at high temperature range of 3-6 MPa).
2、 Running operation process
1. Feed start
After the temperature stabilizes, slowly start the feed pump and control the flow rate to evenly pass the material through the sterilization section (such as a tube or plate heat exchanger).
Monitor the initial discharge status, adjust the throttle valve to maintain system pressure (prevent material vaporization), and ensure that the boiling point temperature is higher than the set sterilization temperature.
2. Real time monitoring and adjustment
Continuous tracking of instrument data: Temperature fluctuations should be ≤ ± 1 ℃, and steam valves should be adjusted immediately when pressure is abnormal.
Liquid materials need to pay attention to fluidity (viscosity changes), while powder materials should be prevented from clogging (particle size should be adapted to equipment).
3. Cooling and discharge
After sterilization, the material is rapidly cooled to below 65 ℃ through a double tube (with cold water/ice water on the outer layer) to avoid denaturation of heat sensitive components.
Control the discharge direction through a three-way valve and connect it to a sterile packaging container or temporary storage tank.
3、 Shutdown and maintenance
1. Safe shutdown
Turn off the feed pump → cut off the heat source (steam) → drain the system materials after the temperature drops below 80 ℃.
Emergency power outage handling: Immediately close the steam valve, open the drainage valve to release pressure, and prevent waste heat from damaging materials inside the equipment.
2. Thoroughly clean
Perform the complete CIP procedure after each use, with a focus on cleaning the fouling on the inner wall of the heat exchange pipeline.
Long term shutdown requires emptying the pipeline of stored water or injecting 1% alkali solution for antifreeze and corrosion prevention.
3. Regular maintenance
Check the oil level of the gearbox monthly (using 32 # engine oil), and verify the accuracy of the safety valve/pressure gauge annually.
Replace vulnerable parts (such as sealing rings) according to their wear condition, lubricate sliding components to ensure smooth operation.
4、 Key precautions
Safety taboos: It is strictly prohibited to operate the feed pump without liquid, chloride cleaning agents are prohibited, and strong acids/strong oxides cannot be sterilized.
Temperature control: During the sterilization stage, the temperature should strictly fluctuate between the lower limit (such as 121 ℃) and the upper limit (124 ℃) to ensure the microbial inactivation rate.
Fault plan: If the temperature or pressure is out of control during operation, immediately activate the emergency exhaust valve interrupt program to troubleshoot heat source or sensor faults.
The above steps integrate the general process of liquid and powder equipment. Please refer to the equipment manual for specific operations.