Date of Maintenance: 2nd to 5th April 2024
Location: National Dairy Development Centre, Yusipang, Thimphu
Maintenance Engineer: Mr. R.N. Bhowmick
Company: M/S ADDCool Trade and Services, Kolkata, India
Under the collaborative agreement between M/S ADDCool Trade and Services, Kolkata, India, and the National Dairy Development Centre, annual maintenance of the Liquid Nitrogen Plant (Stir-LIN 1 Plant) at NDDC was carried out from 2nd to 5th April 2024 as per the Annual Maintenance Contract (AMC). The objective of the AMC is to conduct both preventive and corrective measures to ensure optimal functionality and performance in the production of liquid nitrogen (LN2), a crucial input required for the AI program in the country.
Maintenance Activities Undertaken:
- Preventive Maintenance:
- Inspection of all components: The engineer thoroughly inspected all components of the LN2 plant, including the Cryogenerator, Condenser, Air compressor, Filters, Valves, Tanks, and Control systems to identify any signs of wear, corrosion, and potential malfunctions.
- Lubrication: Critical moving parts were lubricated to ensure smooth operation and prevent friction-induced damage.
- Calibration check: Instruments and sensors were calibrated to maintain accuracy in readings and control parameters within desired ranges.
- Cleaning: Internal and external surfaces were cleaned to remove dust, debris, and any contaminants that could affect performance or hygiene standards.
- Leak detection: A comprehensive leak detection procedure was carried out to promptly identify and rectify any system leaks.
- Corrective Maintenance:
- Part replacement: Certain parts including valves, rings, and filters showing signs of wear were replaced to prevent potential leaks or operational disruptions.
- Control system adjustment: Adjustments (oil change) were made to the control system parameters to optimize performance and ensure stable operation.
- Repair of insulation: Damaged insulation on pipes and tanks was repaired (topping up insulation powder) to prevent heat ingress and maintain the required low temperatures.
Recommendations
Based on the observations made during this maintenance activity the engineer recommended that since the plant has surpassed its shelf life a complete overhauling or modernization of the plant was required to ensure that the Plant will run smoothly for another 10 years. Any LN2 Plants has a guarantee period of 10 years, while the Plant at our Centre (installed in March, 2010) has been operational for >14 years thus there is an urgent need to carry out a major overhaul as per the recommendations of the visiting Service Engineer.
Conclusion
The collaborative efforts between NDDC and M/S ADDCool Trade and Services ensured the successful completion of maintenance tasks, guaranteeing the continued functionality and reliability of LN2 Plant StirLIN-1. The engineer submitted a brief report highlighting the key maintenance activities conducted, emphasizing the need to carry out a major overhaul of the old Plant urgently to ensure its optimal performance and reliability for another 10 years.
