Sediment Cleaning of Water Tanks

There are three water towers on the University of Idaho campus, three more in the city of Moscow, countless more in the United States, and they all have the same problem; sediment buildup. On campus these water tanks are either used for as potable water for drinking or chilled water for the steam plant.

Problem Statement
The Energy Plant of the University of Idaho is looking for a solution to sediment cleaning for chilled water tank. The current approach is time consuming, expensive, and the chilled water service must be stopped during the cleaning process. The current method requires the tank to be drained of almost 2.5 million gallons and having someone from facilities clean it manually. The other option is to hire scuba divers to go in the tank and remove the sediment with a vacuum. That alone costs around $55,000. Water is wasted when it is removed, and the water needs to be chilled to the correct temperature once the tank is operating again. Any chemicals used to prevent rusting and killing bio-growth is lost during the process and has to be replaced. The total cost of the operation is over $230,000 for the chilled water tank. Return to contents

Project Goals

 * Identify the components and properties of the sediment
 * Design a device to remove sediment from tank
 * Versatile design
 * Automatic operation
 * Sediment level detection
 * Permanently installed
 * Inexpensive construction
 * Recirculation of clean water
 * Cleans sediment while tank is operating
 * Make it a self-powered system
 * Build a small scale prototype
 * Create detailed drawings of the full scale model with bill of materials

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Design Specifications
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Design Challenges
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 * Obstacles along tank bottom
 * Turbulence can mix sediment into tank water
 * Large amounts of sediment extracted from tank
 * Ability to use design on multiple tanks (some without flat bottoms)

Alternative Design Selection
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Sweeper Arm Alternatives
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Final Prototype Design
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Team Members
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Document Archive
Meeting Minutes [[Media:MeetingMinutes1.pdf|First Semester]]

Other Documents [[Media:TeamContract.pdf|Team Contract]] [[Media:ClientInterview.pdf|Client Interview]] [[Media:DesignReviewH2Only.pdf|Design Review]] [[Media:DFMEA1.pdf|DFMEA]]

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