Overview
My first project during my internship with AgroFresh Inc. was to help lab technicians be more effective by building a device which would automate a time consuming but simple routine. The lab technicians would spend less time on simple tasks and more time utilizing their skills. I chose to use an Arduino to help regulate the processes in the automation device.
Disclaimer: I can share limited details about the specifics of the system due to company confidentiality
Disclaimer: I can share limited details about the specifics of the system due to company confidentiality
The Problem
Employees in the lab at AgroFresh processed up to 40 gas samples on a daily basis. These gas samples contained valuable data on the storage conditions of fruit across the state of Washington. The samples were collected in bags similar to the one pictured. Once the samples had been analyzed, these bags had to be cleaned of any residual contaminant gases that could throw off the next readings before redeployment. The cleaning process was tedious - each bag had to be individually put through three cycles of vacuum pumping and Nitrogen rinsing. The Nitrogen gas removed any lingering gases. Staff in the lab would spend hours performing this mundane task instead of researching, so my job was to automate this process to free up valuable time.
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Brainstorming
The bags needed to be fully vacuumed out, and then inflated to 3/4 capacity with N2. How would I determine when the bags were empty or for that matter, 3/4 full? My initial instinct was to use pressure sensors, but this proved to be unreliable with small bags that didn't have large pressure differences. Another seemingly plausible approach could have been a volume-based approach, but the size and number of bags could be varied, and determining flow rate would be difficult and unreliable. Finally, there was the time-based approach. Simply program the machine once with the correct time to fill and vacuum, and it will keep the valve open for those times. This approach was simple and effective so I went forward with it.
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