Seed Storage Tube

In developing countries, farmers do not have access to decent seed storage facilities. When farmers try to store their supply of seed, insects and wet climates often destroy it. 
=Problem Statement=
===Background===
In wealthier places like the United States, it is easy to store seed with little risk of destruction by insects or premature sprouting due to moisture. In developing nations, especially in rural areas, much of the loss of crops occurs after harvest, during storage. Insects destroy seeds and monsoons bring moisture that causes the seeds to sprout before they are planted. By providing an inexpensive method of storing seed for long periods of time, we can reduce loss, allowing more wealth and food security for rural farmers.
===Deliverables===
Our main deliverable is an airtight and watertight container inside which seeds collected during harvest can be stored for up to two years for later planting. The container will be vacuum sealed at a vacuum pressure of at most 20 inch of Hg to kill insects mixed in with the seed. It will have an attached vacuum pressure gauge to monitor the integrity of the seal. Included with the container will be a 12v vacuum pump to bring down the absolute pressure and remove water vapor and a tarp to shield the container from rain and direct sunlight. Other deliverables include a visual instruction manual detailing the assembly, use and maintenance of the container.
===Specifications===
Table 1: ME Specifications Matrix 	Table 1: ME Specifications Matrix	Table 1: ME Specifications Matrix	Table 1: ME Specifications Matrix	Table 1: ME Specifications Matrix	Table 1: ME Specifications Matrix
Criteria 	Metrics 	Target 	Priority Level 	 	
Keep seed dry 	% humidity 	Less than 12% 	High 	 	
Store seed for long periods of time	Years of undamaged storage 	Greater than 2 	Medium 	 	
Cheap 	Dollars 	$250 at most 	Medium 	 	
Easy to assemble 	Time of assembly 	Less than 1 hour 	Low 	 	
Transported by hand (2 people) 	Weight 	Less than 200 pounds 	High 	 	
Vacuum 	In. Hg 	-20 In. Hg 	High 	 	
Drawing package 	Pages 	10 	Low 	 	
Water tight 	Time underwater 	At least 3 hours 	High 	 	
Loading time 	Minutes to load 	Less than 10 	Low 	 	
Unloading time 	Minutes to unload 	Less than 10 	Low 	 	
Storage volume 	Cubic feet 	4.7 	Medium 	 	
=Design=
===Alternatives/Selection===
=====PVC Pipe=====
The original design our client proposed was going to be a tube made out of PVC. Once it was determined that PVC at the needed diameters was too expensive, we switched gears and came up with a new idea. 
=====Plastic Drum=====
This second design featured a 55 gallon plastic drum with a removable lid. The valve system was attached to one of the small, threaded openings to allow a vacuum seal. However, the barrel deformed too much when not completely full of seed and air was still able to leak back in at an unacceptable rate. 
=====PVC/Bag=====
The third design is simply a thick trash bag with a PVC tube, with holes drilled into it, and the valve system attached. A 6 mm bag is then sealed around the PVC pipe, allowing the seed to be vacuum sealed in the bag. We were unable to get an airtight seal between the PVC pipe and the 6mm bag.
=====Space Bag=====
Our final design is a modified "Spacesaver Bag". Normally, Spacesaver bags are used by filling them with clothing, closing the opening, and attaching a vacuum cleaner's hose to the valve on the front of the bag, pulling out the air and compressing the clothing inside. Our modification began with filling the valve with silicone caulk, and attaching a through-bag connector to the bag. We screwed the valve assembly into the through-bag connector. Upon applying a vacuum, this system performed better than any of our previous designs. In approximately 13 days, the bag leaked from 22 inHg below atmospheric pressure to 13.75 inHg below atmospheric pressure. Our best leak rate was achieved at -0.026 inHg/hr
PVC Pipe (Design I)	55 Gallon Drum (Design II)	PVC/Bag (Design III)	Space Bag (Final Design)
210px 	 	 	210px
===Components===
	
5/16" Barb x 1/4" Male NPT Air Gas CO2 Hose Beer Shut-off Ball Valve 
Steel Vacuum Gauge with 1/4" Bottom Mount 
1/4" Galvanized Tee 
Two-Piece Aluminum Fitting with Rubber Gasket (Thru-bag Connector) 
Vacuum Space Bag
==Experimentation and Analysis==
=====Plastic Barrel Experiment=====
For this experiment we had to determine at what vacuum pressure the barrel would collapse.
The results of the real-world test on the barrel revealed a few issues. The leak rate of air back into the "sealed" barrel was too high. We thought affixing a gage assembly to the lid would give us an ideal sealed container. Unfortunately, the drum had serious durability problems. The barrel also deformed too much, mainly around the mid-section. Adding seed to the barrel helped it keep its shape but it still leaked air at an unacceptable rate. Under 5inHg of vacuum pressure, the drum began to buckle and implode. Even with a wooden brace inserted and seed filling the barrel, the buckling proved to be too much. The barrel could not maintain a seal for longer than a minute. 
FEA analysis	Structural Integrity Experiment Setup
300px 	
=====Cricket Experiment=====
This experiment was performed to test the life of insects in a vacuum environment. Crickets were chosen as the test specimen. They were put into four separate clear glass soda bottles, corked with a Foodsaver cork, which allows air to be pulled out of a container, but not to flow back in, forming a vacuum, and vacuumed down to different pressures. The results showed that a 20 inHg vacuum would immediately made crickets lethargic, and they died within a few days. Under 15 inHg of vacuum pressure, the crickets survived for almost a week. The food placed in the 10 inHg vacuum bottle spoiled, and the crickets died in three days, but this was disregarded because it appeared they died from starvation or spoiled food, rather than the vacuum. The control group survived for about a week. We continue to aim for 20 inHg of vacuum pressure.
=====Space Bag Experiment=====
This data was quite different than that of the previous leak rate tests as it followed more of a linear trend. For this reason a linear function was chosen to fit the data. As seen from the equation, the leak rate when taken from start to finish is about .026 inHg/hr. This is about 3 times less than the leak rate of .084 inHg/hr for the first thru-bag connector test. According to the equation, if starting at a vacuum of 22.4 inHg the ending vacuum pressure at the end of day 3 should be close to 20.5 inHg. This will ensure a greater insect mortality rate. For these reasons, this design will be chosen as the final design. The addition of oil to the thru-bag connector gasket along with double bagging the seed and adding adhesive tape to the opening of the bag has greatly contributed to the reduction in the bag leak rate.
=Team Members=
Member 	Discipline 				
Joel Wilson 	Bio-Agricultural Engineering				
Joel is a senior in Bio-Agricultural Engineering. Born in Sacramento, CA and raised in Post Falls, ID. His degree emphasis in Eco-Hydraulics and he has completed many civil engineering classes. Over Summer 2016 he did an internship performing soil density testing, concrete testing, and other construction related inspections for STRATA Geotech in Pullman, Washington. His hobbies include reading, playing Dungeons & Dragons with friends and using Unreal Engine 4.	
Joel is a senior in Bio-Agricultural Engineering. Born in Sacramento, CA and raised in Post Falls, ID. His degree emphasis in Eco-Hydraulics and he has completed many civil engineering classes. Over Summer 2016 he did an internship performing soil density testing, concrete testing, and other construction related inspections for STRATA Geotech in Pullman, Washington. His hobbies include reading, playing Dungeons & Dragons with friends and using Unreal Engine 4.	
Joel is a senior in Bio-Agricultural Engineering. Born in Sacramento, CA and raised in Post Falls, ID. His degree emphasis in Eco-Hydraulics and he has completed many civil engineering classes. Over Summer 2016 he did an internship performing soil density testing, concrete testing, and other construction related inspections for STRATA Geotech in Pullman, Washington. His hobbies include reading, playing Dungeons & Dragons with friends and using Unreal Engine 4.	
Joel is a senior in Bio-Agricultural Engineering. Born in Sacramento, CA and raised in Post Falls, ID. His degree emphasis in Eco-Hydraulics and he has completed many civil engineering classes. Over Summer 2016 he did an internship performing soil density testing, concrete testing, and other construction related inspections for STRATA Geotech in Pullman, Washington. His hobbies include reading, playing Dungeons & Dragons with friends and using Unreal Engine 4.	
Joel is a senior in Bio-Agricultural Engineering. Born in Sacramento, CA and raised in Post Falls, ID. His degree emphasis in Eco-Hydraulics and he has completed many civil engineering classes. Over Summer 2016 he did an internship performing soil density testing, concrete testing, and other construction related inspections for STRATA Geotech in Pullman, Washington. His hobbies include reading, playing Dungeons & Dragons with friends and using Unreal Engine 4.	
Joel is a senior in Bio-Agricultural Engineering. Born in Sacramento, CA and raised in Post Falls, ID. His degree emphasis in Eco-Hydraulics and he has completed many civil engineering classes. Over Summer 2016 he did an internship performing soil density testing, concrete testing, and other construction related inspections for STRATA Geotech in Pullman, Washington. His hobbies include reading, playing Dungeons & Dragons with friends and using Unreal Engine 4.
 	 				
David Smith 	Mechanical Engineering 				
David is a senior in Mechanical Engineering. Born and raised in Brewster, Washington. His hobbies include farming and ranching.	
David is a senior in Mechanical Engineering. Born and raised in Brewster, Washington. His hobbies include farming and ranching.	
David is a senior in Mechanical Engineering. Born and raised in Brewster, Washington. His hobbies include farming and ranching.	
David is a senior in Mechanical Engineering. Born and raised in Brewster, Washington. His hobbies include farming and ranching.	
David is a senior in Mechanical Engineering. Born and raised in Brewster, Washington. His hobbies include farming and ranching.	
David is a senior in Mechanical Engineering. Born and raised in Brewster, Washington. His hobbies include farming and ranching.
 	 				
Peter Handel	Mechanical Engineering 				
Peter is a senior in Mechanical Engineering. Born in Kalispell, MT, moved seven times before college and lived in Moscow for the majority of his life. His hobbies include hunting big game and fishing.	
Peter is a senior in Mechanical Engineering. Born in Kalispell, MT, moved seven times before college and lived in Moscow for the majority of his life. His hobbies include hunting big game and fishing.	
Peter is a senior in Mechanical Engineering. Born in Kalispell, MT, moved seven times before college and lived in Moscow for the majority of his life. His hobbies include hunting big game and fishing.	
Peter is a senior in Mechanical Engineering. Born in Kalispell, MT, moved seven times before college and lived in Moscow for the majority of his life. His hobbies include hunting big game and fishing.	
Peter is a senior in Mechanical Engineering. Born in Kalispell, MT, moved seven times before college and lived in Moscow for the majority of his life. His hobbies include hunting big game and fishing.	
Peter is a senior in Mechanical Engineering. Born in Kalispell, MT, moved seven times before college and lived in Moscow for the majority of his life. His hobbies include hunting big game and fishing.
 	 				
Josh Begay 	Bio-Agricultural Engineering				
Josh is a senior in Bio-Agricultural Engineering. Born and raised in Tuba City, Arizona. He is fluent in his Navajo language. His hobbies include going to the gym, hiking and camping with family and friends.	
Josh is a senior in Bio-Agricultural Engineering. Born and raised in Tuba City, Arizona. He is fluent in his Navajo language. His hobbies include going to the gym, hiking and camping with family and friends.	
Josh is a senior in Bio-Agricultural Engineering. Born and raised in Tuba City, Arizona. He is fluent in his Navajo language. His hobbies include going to the gym, hiking and camping with family and friends.	
Josh is a senior in Bio-Agricultural Engineering. Born and raised in Tuba City, Arizona. He is fluent in his Navajo language. His hobbies include going to the gym, hiking and camping with family and friends.	
Josh is a senior in Bio-Agricultural Engineering. Born and raised in Tuba City, Arizona. He is fluent in his Navajo language. His hobbies include going to the gym, hiking and camping with family and friends.	
Josh is a senior in Bio-Agricultural Engineering. Born and raised in Tuba City, Arizona. He is fluent in his Navajo language. His hobbies include going to the gym, hiking and camping with family and friends.
 	 				
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