MECH 4010 & 4015 Design Project I CONCEPTUAL DESIGN REPORT

Transcription

1 MECH 4010 & 4015 Design Project I CONCEPTUAL DESIGN REPORT Industrial Scale Vermicomposting Machine Team 8 Evan MacAdam Willow Sereda-Meichel Joanna Check Lai Shun Man Submitted: November 8, 2013

2 Table of content List of figure... 3 List of table Project Information Project Title Project Customer Group Members Useful Definitions and Acronyms Conceptual Design Summary Background and Context Requirements Functional Block Diagram Concept Classification Trees and Concept Combination Tables Overview of Conceptual Solution Alternatives Concrete mixer with Trommel Screen (Concept 1) Tiered boxes with auger conveyor (Concept 2) Further Automation of Continuous Flow Systems (Concept 3) Feasibility Input method Containment Output signals Input signals Power Source Output method Output filter Testing and verification Early Stage Testing Processing Rate and Sizing of Equipment Verification of Scalability Worm Vulnerability Optimization of Feed Rate Verification Testing Required Engineering Expertise Resources and References Facilities Dalhousie Univ. Dept. of Mechanical Eng. Page 2 of 29

3 11.2. Additional Advisors Funds Works Cited List of figure Figure 1 Swine Manure Vermicomposting, Vermicycle Organics, Tarboro, NC (Sherman 2013)... 7 Figure 2 Soil Corporation Reactor (OSCR) Commercial flow through system (Original OSCR)... 7 Figure 3 Functional Block Diagram... 9 Figure 4 Input Method Classification Tree Figure 5 Containment Classification Tree Figure 6 Output Signal Classification Tree Figure 7 Input Signal Classification Tree Figure 8 Power Source Classification Tree Figure 9 Output Method Classification Tree Figure 10 Output Filter Classification Tree Figure 11 Trommel screening drum List of table Table 1 Weight of compost material at certain time intervals: (in gram) Table 2 Early stage test #1 - Consumption Rate Table 3 Early stage test #2 - Scalability Table 4 Early stage test #3 - Worm vulnerability Table 5 Early stage test #4 - Optimization of Feed Rate Table 6 Verification testing Table 7 Technical Areas of Project Dalhousie Univ. Dept. of Mechanical Eng. Page 3 of 29

4 1. Project Information 1.1. Project Title This final year design project for Dalhousie University s Mechanical Engineering program will be titled Industrial Vermicomposting Machine Project Customer This project is being completed for and funded by the Municipality of the District of Chester. Andre Veinotte, a councillor in Chester and President of Able Engineering Services Inc. proposed the project to Dalhousie University. His contact information is given below. Andre Veinotte Phone: andre@ableinc.ca 1.3. Group Members The group members working on this project are Joanna Check, Willow Sereda-Meichel, Lai Shun Man, and Evan MacAdam. Each team member s contact information is given below: Group Member Phone Number Joanna Check Joanna.Check@gmail.com Willow Sereda-Meichel willowseredameichel@gmail.com Lai Shun Man ls855841@dal.ca Evan MacAdam macadamevan@gmail.com 1.4. Useful Definitions and Acronyms MODC Municipality of the District of Chester Vermicomposting the process of using worms to convert organic materials into vermicast Vermicast worm excretions that can be used as a soil conditioner Feedstock materials that will be input to maintain vermicomposting process Dalhousie Univ. Dept. of Mechanical Eng. Page 4 of 29

5 2. Conceptual Design Summary This conceptual design report details the current stage of design for the Industrial Vermicomposting Machine project. Vermicomposting was proposed by Adnre Venoit as a method of organic waste management for the Municipality of the District of Chester. The scope of this project is to design and build a proof-of-concept, table-top scale model of an Industrial Vermicomposting Machine. The requirements are that the full scale system process 4.5 t of organic waste daily, use organic waste as an input to produce vermicast in a continuous process, require little manual labour, produce no leachate, and have a single input location and a single output location. This report outlines and evaluates proposed solutions in the sub-system areas of: Input method, containment, output signals, input signals, power source, output method, and output filter. The proposed solutions are evaluated based on the criteria of cost, required labour, and manufacturability. It was determined that the most feasible combination of components is an electrically powered, hopper-fed, horizontal containment cylinder with a tapered end, which contains a wall mounted auger flight, after which a trommel screen is used as a separation filter. Furthermore, a detailed description of early stage testing and verification testing is given. The early stage tests describe the methodology that will be used to determine processing rate, verify scalability, test worm vulnerability, and optimize feeding rate. These test results will be used to design system size, input rate, input ratio, and rotation rate. The verification test will be used to prove the capabilities of the prototype in a shortened time frame than will be required for full processing of waste, in order to prove the requirements within the scholastic time-frame of the project. Dalhousie Univ. Dept. of Mechanical Eng. Page 5 of 29

6 3. Background and Context The Municipality of the District of Chester (MODC) currently spends an average of $200,000 per year in transportation and processing costs by delivering 4.5 tonnes per day of their organic waste to neighbouring municipalities. These costs could be greatly reduced if the MODC were to implement an efficient composting method at the Kaizer Meadow Landfill. Andre Veinotte of Able Engineering has proposed the design and creation of an automated vermicomposting system to process the waste. Team 8 (consisting of Joanna Check, Evan MacAdam, Lai Shun Man, and Willow Sereda-Meichel) will design, build and test a prototype for the automated process. Composting can be used to convert the unused landfill waste to a useable product. Vermicomposting is a specialized type of composting using selected species of worms to break down organic waste into vermicast. Vermicast is a more desirable end product than that of standard composting as it is a nutrient-rich fertilizer with the potential to be packaged and sold. The process of vermicomposting also requires days whereas standard composting requires days followed by a 3-4 month curing period (Chaoui, 2010). There are few industrial scale vermicomposting facilities that currently exist in Canada however industrial scale vermicomposting is becoming more common internationally. The most common large scale methods are windrows and continuous flow operations. Windrows consist of long piles of feedstock with added worms which are gathered and sorted annually. Continuous flow operations use long raised containers which are fed from the top and contain a mesh floor through which the vermicast is extracted. These processes require significant labour to operate. Figure 1 shows a method of swine manure vermicomposting. Figure 2 shows a typical continuous flow vermicomposting reactor. Dalhousie Univ. Dept. of Mechanical Eng. Page 6 of 29

7 Figure 1 Swine Manure Vermicomposting, Vermicycle Organics, Tarboro, NC (Sherman 2013) Figure 2 Soil Corporation Reactor (OSCR) Commercial flow through system (Original OSCR) Dalhousie Univ. Dept. of Mechanical Eng. Page 7 of 29

8 4. Requirements Requirements for the design of the vermicomposting machine are based on specifications made by the customer. 1. The vermicomposting machine shall use a specified organic input and output vermicastings. 2. The full scale system shall be capable of processing 4.5 tonnes/day of organic waste. 3. The environment inside the vermicomposting machine should optimize the vermicomposting process. 4. The vermicomposting machine shall have a single point input and single point output. 5. The process shall be continuous. 6. Large undigested waste will be removed from the output 7. The machine shall be designed for use in a fixed location. 8. There shall be no leachate collected from the machine. Dalhousie Univ. Dept. of Mechanical Eng. Page 8 of 29

9 5. Functional Block Diagram A functional block diagram was created to act as an ideation generation aid. As seen in Figure 3, the diagram identifies the sub-functions that will together make up the vermicomposting machine Figure 3 Functional Block Diagram Dalhousie Univ. Dept. of Mechanical Eng. Page 9 of 29

10 6. Concept Classification Trees and Concept Combination Tables Concept classification trees were developed as seen from Figure 4 through Figure 10. These trees demonstrate the brainstorming process that was used to identify feasible design options for each sub-function of the vermicomposting machine. Opening sized for slow release of inputs Hopper dumps straight into machine One hopper, inputs are added one at a time Inputs mixed before entering machine Auger Rotating shaft with mixing paddle Hopper Hoppers dump straight into machine Rotating drum Input Method One hopper for each input, all to same location Layering of inputs by rotating device with one opening to allow inputs from one hopper at a tome Opening Inputs are manually placed directly inside opening Layering of inputs by timed gates at hopper exits Forklift Dump truck Figure 4 Input Method Classification Tree Dalhousie Univ. Dept. of Mechanical Eng. Page 10 of 29

11 Vertical Orientation Horizontal Tilted Containment Multi or single stage container Rectangular Shape Cylinder Tapered towards exit Figure 5 Containment Classification Tree Load Cell Weight of worms/waste Spring Scale ph ph meter Output Signals Temperature Thermometers Thermocouples Moisture Moister meters Figure 6 Output Signal Classification Tree Dalhousie Univ. Dept. of Mechanical Eng. Page 11 of 29

12 Rate of movement of materials inside machine Speed Rate of Inputs entering machine Input Signals On/Off Figure 7 Input Signal Classification Tree Gas Electricity Power Source Methane Man-powered Figure 8 Power Source Classification Tree Dalhousie Univ. Dept. of Mechanical Eng. Page 12 of 29

13 Coreless Auger Built into cylinder/ drum Auger Rotates by shaft Output Method Breaker bar Conveyor belt Ribbed Flat Figure 9 Output Method Classification Tree Figure 10 Output Filter Classification Tree Dalhousie Univ. Dept. of Mechanical Eng. Page 13 of 29

14 7. Overview of Conceptual Solution Alternatives A variety of conceptual solutions were considered using the subcomponents outlined in Section 6 to meet the requirements in Section Concrete mixer with Trommel Screen (Concept 1) The concrete mixer with trommel screen consists of multiple hoppers, a central cylindrical containment unit and a trommel screen at the end. Figure 11 shows a trommel screening drum. Figure 11 Trommel screening drum Sorted waste and bedding is fed into three separate hoppers where the intake flow will be controlled by a rotating mechanism. The main component consists of a cylindrical drum with an auger flight attached to the wall similar to that of a cement mixer. The castings and remaining waste will then feed through a trommel screen separating the castings from unwanted leftover waste. The system should be modular to provide easy transportation of the prototype as well as expansion opportunities for the central sections. Separate hoppers for each input are used to control ratios of of various feeds. A rotating mechanism will be used to allow set amounts of each type of feed to control the environment for the worms. Dalhousie Univ. Dept. of Mechanical Eng. Page 14 of 29

15 This will allow iterations of the system based on conditions. For example, if moisture content is an issue for a particular waste stream, the bedding flow can be increased to help alleviate this. The main component houses the environment for the worms while pushing material toward the end slowly. Worms naturally move away from the vermicast and toward the new food source. This allows them to remain in the system to continue breaking down new feedstock. The design prevents a requirement to have a continuous supply of worms as the worms will breed to capacity in their environment. The cement mixer design was chosen over an auger conveyor on a shaft over concerns with worm mobility in the system. A typical auger conveyer on a shaft may section off the worms and force them out through the output. The vermicast will be separated from unwanted waste at the end of the process by a trommel screen. The trommel fits well into the modular design as well as provides continuous screening as the system rotates. The screen will place the vermicast at a single output location rather than a distributed location discussed in other methods Tiered boxes with auger conveyor (Concept 2) This design consists of a single hopper input that feeds into tiered containers with auger conveyors moving the material. Waste is added to a single hopper at varying times to create layers. The bottom most layer is fed to the top of the next section using an auger conveyer. The end-product is separated from the vermicast using a screen moving on a horizontal axis. The main tiered section is designed to house worms in separate compartments. Worms tend naturally to move toward new food sources and away from the old material. This design was created with that in mind to force the worms into separate compartments to ensure that all food that can be broken down is not abandoned. The worms would be prevented from moving up through the sections by the auger conveyors. The waste is separated from the desired output using a simple screen moving and vibrating to shake the vermicast free. The screen would have to be cleared of the unwanted material periodically based on build up to prevent blockage. This screen is a fairly simple method to operate but may require additional manual labour or additional automation and design to keep clear of large debris. Dalhousie Univ. Dept. of Mechanical Eng. Page 15 of 29

16 7.3. Further Automation of Continuous Flow Systems (Concept 3) Continuous flow systems are currently the most widely used, large scale vermicomposting that are automated. The system consists of long open top containers where feedstock is distributed uniformly across the top of open containers. The worms process the material added to the top layers while the lower layers consist primarily of vermicast. The vermicast is harvested from the bottom layers by sifting it through a screen using a breaker bar. This system has been primarily used to create vermicast as a product rather than dealing with waste streams. The distribution system is typically fixed to a tractor that drives alongside the open top containers which then feeds into the containers. More automated systems also exist where feed can be loaded into a hopper which then moves along rails over top of the containers and distributes the load in a similar fashion. We considered the automated system, as our goal is to reduce the amount of manual labour. Occasionally grinders are added to this distribution system to further break down feedstock. This system creates a beneficial environment for the worms as the feedstock is uniformly distributed in layers. The worms process and digest the feedstock on the top layers. As material is added, the worms continue to naturally move up toward the new food source. Most of the worms can be found near the top and have little interaction with the filtering screen near the bottom. This helps the worms stay in the system. The worms breed to the environment capacity and additional worms are not required. The vermicast is separated from the system using a breaker bar over a screen. The filtering process leaves materials inside of the container to continue to break down. In currently existing systems, the feedstock is heavily controlled so that inorganics that will not breakdown do not make it to this stage. This forces more constraints on the input than other considered systems. Dalhousie Univ. Dept. of Mechanical Eng. Page 16 of 29

17 8. Feasibility The following section analyzes the feasibility of the concept designs by breaking down the sub functions and comparing the implementation of each. The concrete mixer with trommel screen was found to be the most feasible method Input method In concept 1 and concept 2, hoppers were chosen to be the input method. Using multiple hoppers will incur extra costs however it will also give more control over the ratio and layering of materials that are put into the containment section. One hopper would require that all the materials are mixed before going into the system. In concept 3, an automated hopper that moves along a track above the containment section was chosen as the input method. In this method the feedstock needs to be pre-mixed before it goes into the hopper, this may require monitoring of the ratio of the material that is put into the hopper manually. Also it may take an extra motor to run the hopper. It is relatively complex because the movement of the hopper must be controlled, so that the material can be distributed evenly Containment In concept 1, multiple horizontal cylinders tapered towards the exit were selected. Multiple cylinders allow material to go into different parallel streams so that the total weight on a single cylinder is reduced. In addition if any single container failed, the whole process of the system would not stop. The other containers can continue to run as maintenance is performed. The container does not need to be vertical or tilted since the auger flight will be on the wall of the container. As it rotates, it will automatically push the material toward the exit. The volume and weight of the food waste will decrease during the process as shown on Table 1, therefore the volume of the end of the container can be reduced to cut down the weight of the container. Dalhousie Univ. Dept. of Mechanical Eng. Page 17 of 29

18 Table 1 Weight of compost material at certain time intervals: (in gram) Material (g) Start 1 Week 4 Weeks 6 Weeks 9 Weeks Leaves only Leaves & Food Food Only Leaves & Worms Leaves Food & Worms Food & Worms In concept 2, few large boxes are used as the containment of the system to separate feedstock throughout the process. This method will cost a lot and be relatively difficult to build, compared to the other option. Therefore this method is not feasible to build. In concept 3, regular large scale vermicomposting containment section is used. This method is the most cost effectively and easy to build in comparison to concept 1, but it will take a relatively large area to build. Furthermore, it is labour intensive which does not meet the requirements of this project Output signals Worms are very sensitive to the environment, therefore it is necessary to monitor the environment and the amount of worms and waste through volume or mass in the container throughout the process. Monitoring the mass of worm and waste are important because an insufficient number of worms will result in non-decomposed products coming out from the system. A decrease in the mass of worms may also be indicative of undesirable conditions within the system. Monitoring ph, temperature and moisture are necessary throughout the process to construct an environment that the worms can live in so that the population of the worms will not decrease Input signals For concept 1 and 2, the rotation speed need to be calculated since the container needs to push certain amount of waste to intake more waste into the system. The movement of the waste inside Dalhousie Univ. Dept. of Mechanical Eng. Page 18 of 29

19 the container needs to be equal to or greater than the input waste each day. Since the containment section is moving very slow, large gear ratios need to be considered. For concept 3, the movement of the hopper needs to be calculated so that the feedstock can be evenly distributed It needs to be moving fast relative to rotation speeds in the other considered concepts Power Source Electricity will be selected over gas, methane and man powered to be the power source of the machine. It is safer and easier way to operate the motor. An electric power source will not need to be created as access will exist on site. The machine is rotating slowly throughout the day so it is much easier to control the power input to the motor than burning gas or methane. The purpose of this project is to reduce labour, so man powered is not considered Output method For concept 1, an auger flight on the container s wall will be the output method of the machine. This can increase the airflow throughout the container, therefore aerobic decomposition occurs which can reduce the odor from the process. It Also gives a path for the worms to move toward the new feedstock. For concept 2, auger conveyor would be used to prevent worms moving between containment sections while moving material between sections. Since all the auger conveyors are disconnected, extra motors are needed to rotate the auger. For concept 3, a conveyor belt in the bottom of the system will collect the casting after the screening process. The feedstock is always on the top and the casting are always in the bottom, transportation of the feedstock is not necessary Output filter In concepts 1 and 2, a trommel screen is used to filter worms, non-decomposable material, nondecomposed material and vermicast. It can fit into the end of the container and screen vermicast efficiently. Vermicast will drop out during the screening process and the worms, non-decomposable material and non-decomposed material will come out at the end of the trommel for further processing. Dalhousie Univ. Dept. of Mechanical Eng. Page 19 of 29

20 For concept 3, a vibrating screening method is used to filter the casting. However, the screen covers the bottom of the containment section meaning the non-compostable material cannot come out from the system. Therefore, this option is not feasible because the non-compostable material within the feedstock may clog the system and would be manually intensive to remove. Dalhousie Univ. Dept. of Mechanical Eng. Page 20 of 29

21 9. Testing and verification The tests associated with the design are broken into two sections: Early stage testing and verification. Early stage testing is broken down further into four categories based on the purpose of the tests. These categories are: Processing rate and sizing of equipment, verification of scalability, worm vulnerability, and optimization of biological process. Verification tests will be used to prove the product requirements and specifications Early Stage Testing Processing Rate and Sizing of Equipment In order to determine the size of the equipment, the processing capability of the worms is required. Test 1 will be completed in order to answer the questions, How much will worms eat per day?, and, What is the ratio (by mass) of output vermicast to input organic waste? Table 2 outlines Test 1. Dalhousie Univ. Dept. of Mechanical Eng. Page 21 of 29

22 Table 2 Early stage test #1 - Consumption Rate TEST 1: CONSUMPTION RATE Materials: 3 bins 3X lb worms* Dry bedding material 1 ¾ X lb organic waste (feedstock), shredded* Scale, ph meter, thermometer or thermocouple, moisture meter *where X is a value to be determined based on worm availability. Required time (For scheduling): Estimate: 1-4 days day buffer. Purpose: Through research, different sources have given different rates of consumption for worms. Three of the often given rates are ¼ of body mass of worms per day, ½ of body mass of worms per day, and 1 times the body mass of worms per day. Procedure: 1. Set up each bin with bedding materials and worms. Add the same amount of bedding materials and worms to each bin in order to make each bin equal. 2. Measure the mass, temperature, ph, and moisture percentage of each bin. Compare to ensure similar starting conditions. 3. Add the waste. Bin 1: 1X lb Bin 2: 0.5X lb Bin 3: 0.25X lb 4. Mix waste into bedding materials. 5. After 12 hours, check decomposition. Measure the mass, temperature, ph, and moisture percentage of each bin. Record qualitative observations. 6. After 24 hours, repeat step Continue checking at 12 hour intervals until feedstock completely decomposed. Results: This test should give an indication of consumption rate of worms, which will be called N [lb waste/(lb worms*day)]. Using the mass measurements, the reduction of mass associated with the composting process may be determined by comparing the mass of the bin after waste is added to the mass once fully decomposed and accounting for the mass of the worms and the mass of the dry bedding material. Dalhousie Univ. Dept. of Mechanical Eng. Page 22 of 29

23 Verification of Scalability In order to prove that the full scale model will be capable of processing the required mass of organic waste, it must be proven that the mass that can be processed is proportional to the mass of worms in the system. Using the consumption rate found in Test 1, Test 2 will be used to determine the scalability of the consumption rate. Table 3 outlines Test 2. Table 3 Early stage test #2 - Scalability TEST 2: SCALABILITY Materials: 1 worm bin containing 2*X lb of worms 1 worm bin containing X lb of worms 3*X*N lb of organic waste, shredded Scale, ph meter, thermometer or thermocouple, moisture meter Required time (For scheduling): Estimate: 1 day + 1 day buffer Purpose: To verify that scaling the prototype by Z will result in scaling the processing capacity by Z. Where Z is the scale of system to prototype. Procedure: 1. Measure the mass, temperature, ph, and moisture percentage of each bin. 2. Feed the bin containing 2*X lb of worms 2*X*N lb of waste. Feed the bin containing X lb of worms X*N lb of worms. 3. Mix waste into bedding. 4. Check decomposition of waste every 12 hours until waste is fully decomposed. Measure the mass, temperature, ph, and moisture percentage of each bin. Record qualitative observations. Results: The test will be considered successful if both bins result in a fully decomposed condition in the same amount of time. If this is not the case, other tests will be designed to determine if there are other factors other than feed to worm ratio that influence processing time Worm Vulnerability Test 3 will help to determine the reaction of the worms to undesirable feedstock. Undesirable feedstock is considered to be items which, through research, have been determined to be undesirable to the worms (ex. Onions). It will not be possible to sort the feedstock to ensure there Dalhousie Univ. Dept. of Mechanical Eng. Page 23 of 29

24 are no undesirable items; therefore, it must be proven that the worms will not be killed if fed undesirable feedstock. Table 4 outlines Test 3. Table 4 Early stage test #3 - Worm vulnerability TEST 3: WORM VULNERABILITY Materials: 3 bins, each containing X lb of worms 3*X*N lb of organic waste Undesirable waste (ex. An onion) Required time (For Scheduling): Estimate: 10 days + 2 day buffer Purpose: To determine how the input condition of feedstock containing undesirable items affects the consumption rate and health of worms. Procedure: 1. Grind 1*X*N lb of waste (which includes undesirable waste), and allow to thermophilically decompose for 9 days. 2. Once decomposed, grind another 1*X*N lb of waste containing undesirable waste. 3. Keep third X*N lb whole. 4. Measure the mass, temperature, ph, and moisture percentage of each bin. 5. Add each feedstock (Ground and pre-composted, ground, whole) to a bin. 6. Mix feedstock into bedding. 7. In the bin containing the whole feedstock make a note of the location of the undesirable item. 8. Check bins every 6 hours during the day (12 hours over night). Measure the mass, temperature, ph, and moisture percentage of each bin. Record qualitative observations. Look for signs of worms abandoning the waste and crawling up the sides of the container. Check the whole undesirable item, have worms avoided it? Results: The results will help to determine the reaction of the worms to undesirable feedstock, as well as determine if grinding or grinding combined with pre-composting are effective methods to mitigate negative reactions by worms to undesirable feedstock Optimization of Feed Rate Several tests could be completed in order to determine the ideal conditions relating to temperature, ph, and moisture; however, given the short time frame and inaccurate nature of these tests, research will mainly be used to determine the ideal values for each of these parameters. Dalhousie Univ. Dept. of Mechanical Eng. Page 24 of 29

25 One component which may affect the process is the layer thickness of feed. This concern is related to the rate of feeding, that is, will all of the feed be input into the system at a single time during the day, or will it be added in smaller layers throughout the day? Test 4 will be used to determine the effect of layer thickness on consumption rate. It should be noted that the main concern with layer thickness is the possibility of inducing thermophilic decomposition in a thick layer of waste within the system. This is undesirable and should be avoided due to the temperature sensitivity of the worms. Table 5 outlines Test 4. Table 5 Early stage test #4 - Optimization of Feed Rate TEST 4: OPTIMIZATION OF FEED RATE Materials: 3 bins, each containing X lb of worms 3*X*N lb of waste, shredded Purpose: To determine if feeding rate is affected by thickness of waste applied. This can be extended to determine rate of application. Procedure: 1. Measure the mass, temperature, ph, and moisture percentage of each bin. 2. In first bin, add full daily amount of feed on top of bedding. 3. In second bin, add half of daily amount of feed on top of bedding. 4. In third bin, add one third of daily amount of feed on top of bedding. 5. After 8 hours, measure the mass, temperature, ph, and moisture percentage of each bin. Record qualitative observations. Add another third of feed to third bin. 6. After 12 hours, Measure the mass, temperature, ph, and moisture percentage of each bin. Record qualitative observations. Add second half of feed to second bin. 7. After 16 hours, Measure the mass, temperature, ph, and moisture percentage of each bin. Record qualitative observations. Add last third of feed to third bin. 8. After 24 hours, Measure the mass, temperature, ph, and moisture percentage of each bin. Record qualitative observations. Results: Compare the products of decomposition between the bins. Determine if there are any negative effects on temperature, ph, or moisture content with any of the methods Verification Testing In order to verify the prototype in a short time period a test will be completed to determine if the prototype processes waste at the hypothesized rate. The hypothesized rate will be determined Dalhousie Univ. Dept. of Mechanical Eng. Page 25 of 29

26 using the early stage test results, and will have been used in the sizing of the prototype. Test 5 compares the output of the prototype in a certain number of days to the output of a control bin in the same number of days. Table 6 outlines Test 5. Table 6 Verification testing TEST 5: VERIFICATION Materials: 1 started bin, with X lb of worms Prototype started with X lb of worms and bedding material 2*D*N*X lb of worms; where D is number of days allotted for test, N is consumption rate of worms, X is the mass of worms used in the prototype. Purpose: To prove that the prototype processes material at the same rate as a stationary control bin. This will verify that the full scale design will be capable of processing the design rate. Procedure: 1. Add equal amounts of waste to bin and prototype. If equal amounts of worms are not used due to space constraints, use the proportionality determined in Test Allow both systems to process for D days. After D days, remove the contents from each and compare. Results: If the results are similar for both system, and they agree with the design consumption rate, the process will be considered verified. Dalhousie Univ. Dept. of Mechanical Eng. Page 26 of 29

27 10. Required Engineering Expertise The engineering expertise was broken down into four technical areas and divided between group members as shown in Table 7. Table 7 Technical Areas of Project Technical Area Team Member Responsible Level of Expertise 3D CAD modeling and Drawings Willow Intermediate Experimental Testing/Worm Research Expert Lai Shun Beginner Project Management Joanna Beginner Mechanical Knowledge Evan Beginner Dalhousie Univ. Dept. of Mechanical Eng. Page 27 of 29

28 11. Resources and References Facilities Testing the full composting process of one day s input will take a minimum of 22 days. Setting up and performing testing at the Kaizer Meadow Landfill was suggested by the customer to allow for testing to continue after the design project has been completed. The Kaizer Meadow Landfill will be contacted to arrange testing dates Additional Advisors Dr. Prabir Basu is the acting project supervisor of this project. His approval will be required for all purchases made and he will act as an advisor during the design process Funds Funds for this project will be provided by the MODC. A proposal and preliminary budget was made by the members of this project and was approved by the MODC on October 24, The amount of this budget is $10,000. Dalhousie Univ. Dept. of Mechanical Eng. Page 28 of 29

29 12. Works Cited Chaoui, H. (2010, February). Vermicasting (or Vermicomposting): Processing Organic Wastes Through Earthworms. Retrieved from Ontario Ministry of Agriculture and Food: (2007). Literature review of worm in waste management. Sydney, Australia: Recycled Organics Unit Inc. Dalhousie Univ. Dept. of Mechanical Eng. Page 29 of 29