The pharmaceutical industry demands extremely high precision in equipment installation. As one of the core equipment in pharmaceutical production, the installation quality of the mixer directly affects the quality of drugs and production safety. This article, based on installation cases from pharmaceutical enterprises in Shandong region, compiles a detailed installation guide, covering preliminary preparations, core steps, and precautions. Novice practitioners can follow this guide to avoid common errors.

　　1. Preparations before installation

　　1. Equipment verification and inventory

　　Before installation, it is necessary to check against the purchase list to ensure that the mixer main unit, blades, motor, and other components are complete, and inspect the surface for any transportation damage. Special attention should be paid to whether the blade material is 316L stainless steel (commonly used in pharmaceutical grade), and to ensure that there are no scratches, rust, or deformation.

　　2. Environment and space confirmation

　　The installation area for the mixer should have an operating space of ≥0.8 meters reserved, with a ground flatness error of ≤2mm/m. Most pharmaceutical workshops in Shandong are GMP cleanrooms, so it is necessary to confirm in advance whether the installation location meets the Class 100,000 cleanliness standard, clear any debris from the space, and conduct disinfection.

　　3. Preparation of tools and accessories

　　Essential tools include torque wrenches (accuracy ±3%), level meters, dial indicators, lifting equipment (load capacity ≥ mixer main unit), etc. Consumables such as sealant and insulating tape should be prepared in advance to ensure that all tools are calibrated and qualified.

　　II. Core Installation Steps

　　1. Foundation acceptance and fixation

　　- Check the flatness of the concrete foundation and the position of the pre-embedded bolts, ensuring that the error is controlled within ±5mm.

　　- Fix the base of the main unit using expansion bolts, applying the tightening torque recommended by the manufacturer (typically 150-200N·m). Ensure that the bolt protrusion length remains between 5-10mm.

　　2. Installation of transmission system

　　When connecting the motor to the reducer, it is necessary to use a dial gauge to measure the coaxiality, ensuring that the radial deviation is ≤0.1mm and the axial deviation is ≤0.2mm.

　　When installing the coupling, ensure the key slot aligns correctly, and maintain a gap of 0.3-0.5mm between the two ends to prevent abnormal noise during operation.

　　3. Assembly of stirring shaft and paddle

　　- Special lifting tools should be used for lifting the mixing shaft, which should be slowly placed into the mixing tank to avoid colliding with the tank wall.

　　Before installing the propeller blades, it is necessary to clean the contact surface with absorbent cotton dipped in anhydrous ethanol, adjust the blade angle according to the process requirements (common anchor/propeller blade error ≤±2°), and re-measure the perpendicularity after tightening the fixing nut.

　　4. Sealing system commissioning

　　Before installing the mechanical seal, apply medical Vaseline. Ensure the parallelism deviation between the rotating and stationary ring end faces is ≤0.05mm. Adjust the spring compression according to the instructions (typically 60%-70% of the free length).

　　- Before commissioning, a manual turning inspection is required to ensure there is no clamping stagnation, and the rotational resistance torque should be ≤5N·m.

　　III. Special precautions for Shandong region

　　1. Temperature and humidity control

　　In Shandong, where temperatures are high and humidity is high during summer (with an average humidity of 75% from June to August), it is necessary to equip the installation area with a dehumidifier to prevent the motor from getting wet. During winter installation, attention should be paid to the fluidity of lubricating oil, and it is recommended that the ambient temperature be ≥10℃.

　　2. Clean-level sealing treatment

　　The shaft seal area requires dual sealing (mechanical seal + O-ring), with the O-ring made of food-grade silicone rubber. During installation, avoid twisting it.

　　The sealing surface of the paddle blade that comes into contact with the material needs to be mirror polished (Ra≤0.8μm). A biopharmaceutical company in Shandong adopts electrolytic polishing process, which meets USP requirements through third-party testing.

　　3. Compliance acceptance

　　After installation, an Equipment Installation Qualification Report (IQ) is required, with key data including levelness, perpendicularity, operating noise (≤75dB), etc.

　　- Keep installation records in accordance with GMP requirements, including supporting materials such as torque wrench calibration certificates and calibration photos.

　　IV. Common Issues and Solutions

　　1. The mixing shaft is shaking excessively

　　Reason: Deviation in the levelness of the base or imbalance of the blades

　　Solution: Readjust the anchor bolts and calibrate with a level meter; perform a static balance test on the blades (with a weight error of ≤5g)

　　2. Mechanical seal leakage

　　Reason: Poor end face fit during installation or spring fatigue

　　Solution: Re-grind the sealing surface and replace the failed spring; it is recommended to use a bellows mechanical seal (commonly used in pharmaceutical grade)

　　3. Excessive operating noise

　　Reason: Misalignment of the coupling or too small gap between the paddle and the tank wall

　　Solution: Use a laser alignment instrument to adjust the coaxiality; re-measure the gap between the paddle and the tank wall (recommended to be ≥5mm)