Detecting LN2 Tank Failure with a Digital Scale Alarm Monitoring System
Project Overview
Cryogenic tanks are insulated, vacuum-sealed pressure vessels widely used for storing live biological specimens including human reproductive cells and embryos. These samples are invaluable and irreplaceable, so it is important that the tank is kept at temperatures below -135°C. Liquid nitrogen is the most popular cryogenic fluid used to keep tanks cold; however, heat transfer, imperfect vacuum seals, and liquid tank venting are all factors that lead to liquid nitrogen depletion. Thus, it is imperative that cryogenic tanks are refilled periodically to replenish liquid nitrogen levels to prevent tank failure. In order to safeguard against failure, monitoring systems for storage tanks are essential. Liquid level monitoring systems currently exist but are primarily used for threshold monitoring. There is an unmet need in the cryogenic storage market for a system that warns of failures in advance rather than simply reporting when they occur. Because there is a direct relationship between the weight and the level of liquid nitrogen within a tank, an improved method to monitor liquid nitrogen tanks would be to measure the change in weight over time. The design team is tasked with developing a weight-based monitoring system for the client, Dr. Jeffrey Jones, whose clinic uses cryogenic tanks for storing biological specimens in liquid nitrogen. The monitoring system should continuously monitor the weight of the tank, log data, and send warnings regarding critical liquid levels, excessive leakage, and potential failures. The team plans to develop a “smart” system to detect external events to the storage unit (such as lid removal, LN2 refill, etc.) by analyzing patterns in the change of weight and temperature. This paper discusses the current state of liquid nitrogen monitoring, the motivation for building this weight-based system, and how this alternative design will help reduce the frequency of small cryogenic tank failures.
Team Picture
Files
- PDS (December 16, 2018)
- Preliminary Presentation (October 5, 2018)
- Preliminary Report (December 16, 2018)
- Final Poster (December 16, 2018)
- Final Report (December 16, 2018)
Contact Information
Team Members
- Jeffrey Tsai - Team Leader
- Yiqun Ma - Communicator
- Jacob Andreae - BSAC
- William Guns - BWIG & BPAG
Advisor and Client
- Prof. Sarah Sandock - Advisor
- Dr. Jeffrey Jones - Client
Related Projects
- Spring 2019: Evaluation of LN2 Dewar Health Using a Weight-based Monitoring System
- Fall 2018: Detecting LN2 Tank Failure with a Digital Scale Alarm Monitoring System