April 30, 2004
Egstractorz
Gauss Engineering
University of Idaho
Moscow, ID 83844
Email: me-egstractorz@uidaho.edu
Ron Hardy
University of Idaho
Moscow, ID 83844
Dear Mr. Hardy,
Attached is the final design details and analysis for the Anguous moth incubation and separation
units. Included also is the process description, testing conclusions, and complete assembly and
drawing package.
Mechanical Engineering and Biological Systems Engineering students have worked to achieve
the optimum design for the incubation and separation systems with respect to your requests.
Many critical steps have led to the success of the project: the quick creation of the original
system and ability to study the live moth eggs, frequent communication and diligent group work,
and biological and statistical laboratory testing to determine optimum egg retrieval.
This report is a summary of our findings and calculations completed during the Fall 2003 and
Spring 2004 academic year. Included within the report are system designs, benefit analysis, cost
analysis, detailed SolidWorks drawings, and manufacturing assembly instructions.
Thank you for your time and the funding of this project.
Sincerely,
Austin Bingaman
Carrie Nordby
Kyle Gutknecht
Krista Wabrek
Tofor Snider
Enclosure: Final Design Report
Prepared for:
Ron Hardy
Luis Mazuera
Steve Beyerlein
Design of an Anguous Moth Egg Incubator and Separator
Senior Capstone Design, 2003-2004
Prepared by:
Austin Bingaman, ME Student
Carrie Nordby, ME Student
Kyle Gutknecht, ME Student
Krista Wabrek, BAE Student
Tofor Snider, BAE Student
Executive Summary
The creation of a moth egg production system was to be designed and constructed as a capstone design
project for senior level mechanical engineering and biological science students. Existing moth egg
production methods required high labor and rendered inadequate production rates. The customer
requested a moth egg incubation and separation system that will produce 500 grams of eggs every week
that is at least 70 percent clear of foreign material.
Thorough analysis of existing incubation and separation methods, coupled with studies on the biological
needs of the moth eggs, had led to the final incubator and separator design. High consideration in design
was given to reducing cost of initial system and labor to operate incubation and separation units.
The final incubator design allows for expansion of incubation area to ten times the size of the client’s
existing technology. Improvements upon previous methods are incorporated, along with the addition of
desired features. Features include: 15000 square inches of moth egg infestation area, three doors for
accessibility to screens, caster wheels for transport, construction from sturdy and inexpensive
materials(steel, tin), top lid for infestation, corrosion resistant coating, 27 infestation screens, within
budget, and high production rates. Construction of the framed screen for infestation is similar to previous
technology. All materials used are available locally, and manufacturing requires ability to cut, weld, and
bolt steel, aluminum, and tin.
Separator systems have been researched and thoroughly studied. Preliminary testing on biological
material demonstrates the success of using vibrating screens to produce high egg purity with low losses.
The Separator design solution attaches to the base of the incubation unit, and consists of an angled
vibrating screen and an angled Teflon shelf. The system is completely automated, greatly decreasing the
required manual labor (as compared to existing technology). Eggs are ultimately contained within a
collection jar for easy accessibility, and final purity is nearly 80%.
The final solution was shown to be cost effective and efficient in required egg production. Design
objectives were met and often, exceeded.
Table of Contents
EXECUTIVE SUMMARY..............................................................................................................i
1.0
BACKGROUND INFORMATION………………………………………………………1
2.0
2.1
2.2
PROBLEM DEFINITION
Design Specifications for the Incubator..………………………………………….………1
Design Specifications for the Separator ..…………………………………………………2
3.0
3.1
3.2
3.3
3.4
3.5
INCUBATOR CONCEPT CONSIDERATIONS AND DESIGN DECISIONS
Construction and Analysis of Previous System: The Drum Incubator………………..….2
Design Solutions Considered: Wooden Funnel..……………………………………..…..3
Design Solutions Considered: Iron Door..………………………………………………..3
Design Solutions Considered: Multi Unit..……………………………………………….3
Design Solutions Considered: Cancan..…………………………………………………..4
4.0
4.1
4.2
SEPARATOR CONCEPT CONSIDERATIONS AND DESIGN DECISIONS
Design Solutions Considered: Vibrating Separation..……………………………………4
Design Solutions Considered: Conveyor Separation..……………………………………5
5.0
5.1
5.2
CONCEPT SELECTION/ PRODUCT DESICRIPTION
Incubator..…………………………………………………………………………………6
Separator ……………………………………………………………………………….....7
6.0
6.1
6.2
EVALUATION: ANALYSIS AND TESTING
Biological Observation and Testing…………………………………………………..…..8
Statistical Screen Angle and Purity Testing Analysis………………………………….…9
7.0
ECONOMIC ANALYSIS……………………………………………………..……..….11
APPENDICIES
Appendix A.
Appendix B.
Appendix C.
Appendix D.
Appendix E.
Appendix F.
Appendix G.
Appendix H.
Incubator Assembly View and Drawing Package
Incubator Bill of Materials
Separator Assembly View and Drawing Package
Separator Bill of Materials
Egstractorz Timeline
Egstractorz 2003-2004 Budget
DFMEA Results
Egstractorz Team Member Resumes
1.0
Background
The Idaho Aquaculture Center desires to mass produce angoumois moth eggs because of their
high protein content and possible success as salmon food. Because these moths were viewed as a
pest, there was very little research involving their mass production. While entomological
suppliers produce large quantities of moths and moth eggs, these techniques are highly guarded
by the company for business purposes. As a result, known current methods of producing these
moth eggs through incubation are inefficient and labor intensive.
The production of moth eggs is separated into subdivisions: incubation and separation. The
incubator must accommodate the moth's specific biological system for the thirty day cycle of the
moth. The separator must remove inert matter from the eggs and deliver them to a container for
use. The former methods of incubation have resulted in the recovery of an inadequate amount of
eggs, and previous methods of separation had required many hours of labor. Existing technology
instated by the client will be redesigned to optimize egg production rates and minimize cost.
In order for the production of moth eggs to render success as an alternative fish food, the client
must have the ability to produce a large quantity of eggs through a process of continual recovery.
The objective of the Egstractorz team was to design and manufacture this system using existing
resources, thorough analysis, and innovative concepts.
2.0
Problem Definition
The Idaho Aquaculture Center requests an efficient method of mass production of Angoumois
moth eggs. The two main areas of design include the incubation of moth eggs and the separation
of these eggs from unwanted material. An incubation unit will be designed using existing
technology, elaborating on cost, manufacturing ease, volume of incubator and mass of eggs
produced. Current technology was not suitable for the quantity and cost constraints required for
the incubation of the Angoumois Moth. A separation system will be designed fabricated that can
gently and consistently remove unwanted matter from usable media.
2.1
Design Specifications: Incubator
- The incubator must have a cost under $0.15 per square inch of screen area.
- The incubator must have the capacity to handle 10 grams of initial infestation media
- The incubator must have access to internal components for sanitation between cycles.
- The incubator must have a component to collect wanted media, and this component must
be removable.
- The incubator should contain components that allow observation of the process without
compromising containment.
- The incubator should be able to produce 500 grams of usable media per week.
2.2
Design Specifications: Separator
- The separator must be able to separate 500 grams of usable media from foreign media in
1 hour.
- The separator must use a dry separation technique.
- The separator must be able to run for 4 hours without maintenance.
- The separator must produce 70% pure usable media.
- The separator must accumulate the wanted media in removable container.
- The separator should operate without supervision after initial start.
- The separator should have accessible components for sanitation.
- The separator should not harm any usable media.
3.0
Incubator Concept Consideration
The first main goal of the project was to design an incubator that met all the specifications. Since
there was no current technology that could be observed and evaluated the concept background
came from two areas. The first area consisted of researching current incubation systems
involving small flying insects. Incubators researched had the basic features of what was needed
but lacked the detailed characteristics of an incubator specifically designed for moth eggs. It was
also necessary to construct the current technology to get a visual idea of a working system.
3.1
Construction and Analysis of Previous System: The Drum Incubator
The customer was very experienced with incubation systems and
had all the necessary resources to construct a current technology
model. Because of his strong background the current technology
incubator was based off of what the client had previously used.
After several meetings enough information was obtained to
manufacture a working current technology model. The current
technology model, or Drum incubator, was constructed of materials
specified by the client and had approximately the same capacity as
what the customer previously used.
The construction of the Drum was very beneficial. During the
construction of the unit many potential manufacturing problems were recorded so that they could
be considered in the next generation incubator. Likewise, things that worked well were also
documented. For example, it was found that cutting the drum was time consuming and
potentially dangerous, depending on what the container was used for. This pushed the next
generation models away from 50 gallon drums. Once the Drum was built and evaluated for
efficiency and accessibility, many problems arose. The shelving system was very insufficient
because in order for removal it required the use of a ladder and ability to reach the bottom
shelves was limited to persons with above average arm length. The cost of this unit was around
$135 with an estimated time of construction around 12 hours.
3.2
Design Solutions Considered: Wooden Funnel
The first concept was named the Wooden Funnel. This design
contained many of the same features as the Drum but
addressed the key issue of space. The Drum incubator had a
round containment unit where the wooden funnel consists of a
square containment area. This eliminated much of the dead
space around the shelves and enabled the unit to occupy a
smaller floor space while maintaining its original capacity.
The cost of this unit has also been reduced from the $135of the
Drum to $68. This was beneficial to the customer and to the potential for mass production
capabilities. Since the unit consisted of only square components and the funnel material was
changed, the estimated construction time was dropped from 12 to 8 hours per unit.
3.3
Design Solutions Considered: Iron Door
The second concept was called the Iron Door. This design
greatly increased the ease of use by adding a swinging front
door and slide in trays. It also addressed the issue of space
conservation. The funneling apparatus was removed and
replaced with a sliding tray and, again, the components are all
square minimizing floor space as well as adding the capability
of being stacked. This concept also contained a sliding
collection tray at the bottom for removal of media. The
material that was going to be used in construction was steel and tin. This unit required a higher
technical ability to construct, compared to other concepts, due to the use of welding and skill of
the fabricator. The cost of this unit was reduced from $135 to $54.00 and has roughly the same
capacity as the Drum. The time to fabricate one unit was estimated at 7 hours.
3.4
Design Solutions Considered: Multi Unit
The third concept was called the Multi-Unit. This concept was
mainly a scalable model of the Iron Door. The Multi-Unit’s
key feature was the ability to be scaled to a desired capacity.
Some component features were sliding shelves, front flaps that
could be opened, and sliding bottom trays. This unit
eliminated the funneling and took advantage of the square
design which gave it the capability of being stacked. The
design material was pine lumber and visquene for the cover.
The Multi-Units scalable size could lead to large size and weight and could be very difficult to
move. The flap design might compromise the containment because it might not completely seal
every use. This unit was scaled down in size to make the cost comparison relative to the capacity
of the Drum. The cost was estimated at $35, with a fabrication time of 6 hours.
3.5
Design Solutions Considered: Cancan
The final was called the Cancan. This unit was very similar to
the Drum except for the funneling component. The customer
thought that the funnel design on the drum was to expensive
and time involved so it was rethought in the Cancan. The result
was a material change from Plexiglas to visquene. This
decreased the cost to $64.15 and lowered fabrication time to 6
hours. This concept is the least radical and replicates the current
technology more closely. It also contained critiques that the customer gave on the Drum
incubator.
4.0
Separator Concept Considerations
The second objective of the project was to design a separation system with the design
specifications given in the background section of this paper. The separator concepts evolved
from the research of current separation techniques. The main areas viewed were areas involving
the separation of heavy media from light media and large media from small media. The four
types of separation that were considered were vacuum, rotary screening, cyclone and vibrating
screen. Originally, the customer wanted a central separation unit that would have media
manually brought to the separator. After several meetings with the customer, it was decided that
the process should be interfaced with the incubator and should separate media before removal
from the system. Since all previous concepts were for a central separation unit, they could no
longer be used unless modified.
Screening was determined to be the most controllable method for separating the eggs from the
media. This was determined by performing biological laboratory tests using moving air and
vibration. Screen characteristics, such as size, were determined after obtaining moth eggs.
Taylor screens were obtained so that tests could be preformed to see how the media responded to
a vibrating screening. Data was taken and analyzed to get a better idea of the purity of eggs
verses screen size. Visual inspection proved to be efficient, as well as weight analysis. From
data and research, two separation concepts were derived.
4.1
Design Solutions Considered: Vibrating Separation
The first system consisted of vibrating screen. The
funnel on the incubator would interface the separator
diagonally along the separation tray with a flexible
plastic connected to each system with bolts. The
upper tray of the separator had a screen lining and
would be mounted to a sub frame by dampers. This
Flow
Flexible
Plastic
Screen
Collection
Tray
Figure 1
tray extended past where the funnel interfaced the separator and the bottom returns to solid sheet.
This area beyond the funnel allowed a space for moth media to collect and be removed
occasionally. The lower pan was a solid sheet that separated egg media would fall on to and
slide into a removable collection tray at the bottom. The vibration in the system would have been
supplied by a motor mounted under the upper tray.
4.2
Design Solutions Considered: Conveyor Separation
In this concept a hinged bottom door was at the
bottom of the funnel that could be opened and
would drop the media onto a conveyer. The funnel
was simultaneously sealed with a sliding door
above the hatch. The conveyer vibrates the media
as it moves, all usable media is contained in the
tray collection area. One major problem with this
system is being able to vibrate the media as well
as drive it forward simultaneously. This means
that the gears or rollers would need to support
horizontal loads as well as tangential loads. Also
the trap door would require a system that could
automate the sliding block to keep the system
contained.
5.0
Concept Selection
5.1
Incubator
A summary of the incubator concepts are in the table presented below. This data was presented
to the client and the Multi-Unit was chosen as the preferred design due to low cost and high
capacity. Also, new criteria was presented by the client that design must meet. The incubator has
ten times the capacity of the original Drum design, and integrated with the separation unit. Using
the system of a “funnel” for egg collection is preferred by the customer (as used in previous
technology, the drum incubator). The chosen material was analyzed for stress concentration with
the tray in excess of 15 lbs each. The unit will contain three columns of shelves with nine rows
of screening. Complete detailed view, as well as bill of materials and assembly instructions can
be found in the appendix.
Lid and Doors The front doors were placed on hinges to allow
easy access and removal of the shelving components. The top of
the incubator also has a hinged door, but is covered with a cloth
to allow for ventilation throughout the incubator and protection
from predators. The incubator frame and doors are constructed
out of steel with shelving made of pine and fiberglass screening.
Containment is assured around all of the doors and lid by lining
with poly foam (maximum compression) weatherseal and with
the use of black silicone.
Screens The screens are constructed similarly to previous design
due to success and low cost of this existing technology. Screen
frames are made of pine wood (as before) with fiberglass screen.
A reinforcement bar is added to decrease deflection of the screens
due to the increase in frame size. Screen area totals 15000 square
inches. Screens are easily reproducible.
Material Selection and Protective Coating Steel is chosen as
the frame construction material. This material has high durability,
is inexpensive, can be welded with ease, and readily available
locally. Tin sheets (around the perimeter of the unit) and cloth (for
the lid) will enclose the unit to ensure containment. Materials
were chosen due to their compatibility with the biological cycle,
customer recommendations, and inexpensive cost. Paint was
applied to the unit (after thorough cleaning and paint primer) in
order to increase corrosion resistance due to high humidity/high
temperature nature of this biological process.
Size and Orientation of Unit The Incubation unit was constructed to include
ten times the screen capacity of previous technology. The unit was also
designed to fit through a standard door for ease of moving. Doors and screens
are accessible at a height that is convenient for the customer to access. Caster
wheels are incorporated into the design at the base of each of the four legs for
ease of movement of heavy unit.
Structural Assurance The
incubator was designed in
order to withstand added
weight of screens, biological
material, and additional forces
that might be unforeseen.
The material selected for cost
and availability (steel) is
shown to provide additional
structural stability. Upon
structural analysis using
SolidWorks Cosmos, the
maximum deflection of the
entire incubator is shown to
be a few thousandths of an
inch fully loaded.
5.2
Separator
The final separation design, the Vibra-Screen, was developed to achieve appropriate media
purity, low cost, and ease of use for operator. The design is angled with an attached vibration
motor in order to sieve and collect eggs within a collection jar. The unit is attached at the base of
the incubator.
Frame Material Selection Aluminum was chosen as the material for the frame due to low
weight of material, ability to be welded, cost, and availability. The separator framework was
constructed from 6061 T6 structural aluminum. All joints were welded together, this makes the
framework very ridged. This is necessary because vibration must transfer throughout the entire
frame.
Screening Shelf Precision Screening was properly sized
during laboratory experiments in order to achieve appropriate
purity objectives. The Upper shelf is lined with a .03" opening
Nylon mesh. This is the area where the moths will lay the eggs
on. The screen was attached to the upper shelf by sandwiching
it between the frame work and a piece of 1"X.125" flat
aluminum bar. The flat bar was then bolted to the frame work.
By using this attachment method we were able to stretch the
screen to the desired tension uniformly across the entire
separator.
Air Vacuum System An adjustable air vacuum system is
installed into the separator to remove un-usable media from the
product. Unwanted media is collected in the upper shelf (using
air vacuum system). In addition, the vacuum is used to separate
dust from the media after it travels through the precision
screening. The vacuum may be de-attached and cleaned.
Collection Jar A Collection jar is attached to the separator to collect useful
media. The plastic container can be removed from the system by unscrewing the
jar from the lid (lid remains attached to the unit). Media is transferred down with
vibration, and funneled into the collection jar. The jar may be detached, useful
media removed, and the jar may be cleaned.
Teflon Sheet Shelf Teflon film is chosen as the lower shelving
material due to the material’s low coefficient of friction (ability of
media to slide easily to collection units). This material is durable
and will assure that the small media (eggs) will “slide” to the
collection jars. The bottom plate was bolted to the shelving frame
work. This allows the user to replace the Teflon and remove the
bottom plate if maintenance on the frame is required.
Vibrating Motor The motor selected for the separation system is a 120
volt, 47lb, linear vibrating motor. The motor was attached to a timer in
order to perform without complete operator imput. The motor and timer
swich are mounted to the side of the shelving unit by a single .5" bolt.
This mounting gives the user the ability to rotate the motor to achieve a
better flow pattern.
Vibration Dampening Mounts The vibrations of the separator is separated from
the surrounding incubator by specifically sized dampening mounts. These rubber
attachments will reduce noise to floor and surroundings.
Plastic Enclosure and Containment Plexiglass, silicone, and
plastic are used to fully contain separator from surroundings.
Weatherseal is also implemented around the doors and lid to ensure a
complete seal. Containment of live media is critical, and it is
assured that incubator and separator are fully contained. A rubber
flap at the low end of the precision screen allows the separator to be
contained fully even when the motor is off.
Attachment to Incubator The separator is attached at the bottom
of the incubator. Allowing the incubator and separator to be one unit
decreases the manual labor involved in transporting media, as well as
transporting the unit. Vibration dampening mounts assure that
minimal vibration will be released to the incubator funnel.
Accessibility The separator is designed so all regions contained
within may be accessed by an operator after customer requests for ability to
brush out the separator. For the separator, plexiglass is hinged to the outward
facing side for access to the lower Teflon shelf (accessible like a door) and
also at the lower section of the precision screening near the vacuum exit.
Containment is assured with additional strips of weatherseal and convenient
latches.
6.0
Analysis and Testing
6.1
Biological Observation and Testing
Due to the biological nature of the design objectives, the moth species was researched and
studied. In addition to the moth’s optimum humidity and temperature conditions for growth, it
was found that the desired moth egg media was oblong, and less than half of a millimeter in
length. Moth eggs were purchased from a national supplier, and testing ensued.
Experiments for separation of moth eggs included using air (as previous technology) and
methods of sieving. Precision Taylor screens were obtained and used for testing. It was found
that sieve size #30 obtained high purity (up to 70%) with minimal losses. It was also determined
that sieving through multiple screens did not greatly increase purity rates of the media.
To optimize the use of the incubator and to decrease waste if wheat and infestation media,
biological testing was conducted. The objective of testing was to determine the optimum ratio of
eggs used to infest a certain amount of wheat. To run such tests, 3 small-scale incubators were
constructed. These incubators were made out of nine inch pie tins with holes punched in the
bottom (the size of pin holes) to allow for the movement of air, moth eggs, and larvae.
Each incubator was infested with varying amounts of eggs. Previous technology used 10 grams
for infestation, so testing was performed using a percentage of this mass. For the small-scale
experiment, three infestation rates of 200% (20 grams), 50% (5 grams), and 100% (10 grams) of
infestation media per barrel area of wheat were used. The actual amounts used for infestation of
the small scale incubators where 1.6971 grams, .426 grams, .8503 grams respectively. Soft white
winter wheat was used as the food source for the incubators. To prepare this media for
infestation it was placed in the incubation trays for 1 week and placed in the environmental
chamber to allow for re-hydration.
The incubators where allowed to run for thirty-seven days. To analyze how many moths where
produced, the moths where separated from waste material. Moths produced were counted (from
weighted sample). The number of moths produced by each incubator is as follows:
 20 grams infestation (200% of the previous technology) produced 8274 moths.
 5 grams infestation (50% of the previous technology) produced 4341 moths.
 10 grams infestation (100% of the previous technology) produced 6309 moths.
Data was scaled back to 100% infestation rate, and graphed to a logarithmic model (shown in
Figure A), which is the model commonly used to model the growth of a biological object in
relation to a limited food source. As the amount of eggs increase, the food source becomes
depleted, and therefore, additional eggs infested have no effect on moth production. The
relationship between the amounts of eggs infested to the limited amount of food creates an
asymptotic graph. It is suggested that further testing includes infesting and testing 20g of eggs
per barrel area of wheat.
Production Model
Numbers of Moths
120000
100000
80000
60000
40000
20000
0
0
5
10
15
20
25
30
35
40
Gram s Eggs
Figure A: Moth Egg Production Model
6.2
Statistical Analysis
A project was performed concurrently with a Mechanical Engineering Senior Laboratory class in
order to statistical determine the optimum screen angle.
7.0
Economic Analysis
High consideration in design was given to reducing cost of initial system and labor to operate
incubation and separation units. The final cost to create the incubator and separator (materials
only) is $1250. This is equivalent to $0.03 per square inch of screen incubation area, which
exceeds the initial objectives set forth by the design team and customer. The complete
Egstractorz budget for the 2003-2004 academic calendar may be seen in Appendix F. A
synopsis of the cost to reproduce the delivered design can be seen in Table 1. This analysis
includes projected fabrication costs, as well as material and hardware costs.
Cost to Reproduce Design
Incubator
Materials
$180
Hardware
$80
Separator
Materials
$220
Hardware
$409
Professional Services
Fabrication
Hours
60
Rate
$60.00
Grand Total
$3,600
$4,489
Table 1. Economic Analysis for reproducing design.
An economic analysis of value of the Egstractorz Capstone Design Project, including design and
fabrication time, is shown in Table 2. This table includes analysis of projected labor costs
(engineering designers and fabrication time).
Economic Value of Project
Drum Incubator
Materials
$150
Incubator
Materials
Hardware
$180
$80
Separator
Materials
Hardware
Professional Services
Engineering
Laboratory Testing
Fabrication
Grand Total
$220
$409
Hours
120
12
80
Rate
$75.00
$75.00
$60.00
$9,000
$900
$4,800
$15,739
Table 2. Economic Analysis including theoretical Egstractorz labor fees.