P19318: Thermochemical Conversion of Food Waste
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Preliminary Detailed Design

Table of Contents

This Preliminary Detailed Design phase is when we do feasibility analysis on our high priority components and to research how to mitigate or eliminate our highest risk factors.

Content related to this node is locate in the Detailed Design Documents directory.

Team Vision for Preliminary Detailed Design Phase

Our plan for this phase is to perform a deep analysis on the feasibility of our high priority subsystems and functions. These high priority items include where to drill into the biogenic refinery and how to seal those holes to prevent exhaust gas from leaking out and air from leaking in. Performing a feasibility analysis on the small computer that will be used in our system. Purchasing and testing the circuitry and components required to convert the analog thermocouple signal into a digital signal. The preliminary code that will be used to run and control our system. Finally, testing the thermocouple, outside the biogenic refinery, to ensure our electrical components are compatible.

During this phase, our team accomplished designing a mounting block for the thermocouples in the fire pot and researching potential sealants to be used. For the electrical components, we were able to configure the raspberry pi and test all the individual components including Op-amps, MUX and ADC's. These components were later added together to construct an initial prototype.

System Integration Feasibility

One of our largest risks is not having an effective seal around the holes we need to drill into the refinery. To mitigate this risk, we researched different high temperature sealants that we could use and found a couple that should be within the temperature range the gases against the seal should face. However, before we select a sealant we will position a thermocouple to measure the temperature on the inside near the wall to know what the actual temperature range is. A cost feasibility analysis can be found here. It was determined that the Permatex High Temp RTV Silicone Sealant is the most cost effective sealant.
Sealant Feasibility

Sealant Feasibility

To ensure that the available thermocouples (TC) will work for the Biogenic Refinery, the length of these TC was tested.

  1. One TC was inserted into the gap between the Airtube and the Carbonizer skin, until it bumped into the edge of the Firepot, see Step One.
  2. Then the TC was curved up towards the top of the Firepot.
  3. The TC was then curved over the Edge of the Firepot.
  4. The TC was pulled as low as it would go into the fire pot, away from the clinker basher.
  5. The length of the TC inside the Firepot was measured.
  6. The length of the TC that remained outside was also measured.

Step Two Step Three Step Four Step Five Step Six Step Seven

This initial test allowed for a depth of 7 inches, with an excess of 6.5 inches hanging out of the refinery. After this test it was determined that the lowest TC will be placed 7.5 inches into the Firepot.

The last portion of the System Integration for the Preliminary Detailed Design Phase is measuring portion of the Biogenic Refinery to get the locations of the desired TC location These measurements will be reflected in the TC Location Drawing, found in the "Drawing and Schematics" section. The following measurements were made:

Position Label Measurement (in)
Edge of Firepot to Firewall A 2.5
Top of Airtube to top of Firepot B 2.75
Outer Diameter of Firepot C 17.5
Edge of Baffle to Firewall D 21
Top of Airtube to top of Baffle E 12.5
Bottom of Fuel Tube to Top of Air Tube F 14.25
Edge of Cat to Inside Wall G 22.5
Catalytic Converter Diameter H 6
Thickness of Firepot, avg I 1.65
Width of Carbonizer, Outside - 38.75
Width of Carbonizer, Inside - 22

Sketches from this feasibility study can be found below.

Front View Step Three Step Four

Electronics Feasibility

Candidate Components List

Candidate Component Feasibility List

Candidate Component Feasibility List

Bill of Materials

Since our project has two main parts to it, Data Acquisition and System Integration, we decided to split our Bill of Materials (BOM) up into two separate BOMs. One BOM will deal all with the Data Acquisition and the other will deal with System Integration. Since our high risk items for the Preliminary Detailed Design Phase was the electronic portion of the Data Acquisition, only the EE component have been picked out. Once the individual components have been selected, the protective case will have enough constraints to be designed. The full BOM can be seen here.
Data Acquisition BOM

Data Acquisition BOM

System Integration BOM

System Integration BOM

Electronics Test Plan and Prototyping

A test plan of the Electronic components can be seen here.

Electronics Test Plan

Electronics Test Plan

The testing was performed in the lab to ensure proper working of the components. After individual testing of these components, a circuit was constructed on the breadboard with all the components for an initial circuit prototype.

Circuit schematic of initial EE prototype design.

Circuit schematic of initial EE prototype design.

Picture of initial EE prototype design.

Picture of initial EE prototype design.

Picture of possible size footprint estimation for the DAQ system (besides the small computer/Raspberry Pi).

Picture of possible size footprint estimation for the DAQ system (besides the small computer/Raspberry Pi).

Drawings and Schematics

Ideal Sensor Location in Carbonizer

Ideal Sensor Location in Carbonizer

Ideal Sensor Location in Firepot

Ideal Sensor Location in Firepot

Thermocouple Mount Concept

Thermocouple Mount Concept

Front View of Mount Concept

Front View of Mount Concept

Back View of Mount Concept

Back View of Mount Concept

Thermocouple Mount Drawing, to be Manufactured Week of 12NOV18 to 16NOV18

Thermocouple Mount Drawing, to be Manufactured Week of 12NOV18 to 16NOV18

Risk Assessment

Updated Risk Response Matrix

Updated Risk Response Matrix

Our risk assessment document can be found here.

Design and Flowcharts

Design flowcharts were detailed enough to not change yet, as specific devices have not yet been chosen. The circuit diagram above is a detailed example of how the data flow could work with the system, but the part and layout has not been finalized yet. The design flowchart may be found here.
Data Flow

Data Flow

Plans for next phase

By the end of the next phase, we want to have completed feasibility studies for the remaining, low-risk subsystem components. We aim to have a functioning prototype of the core components and be ready to integrate our system into the BGR by the beginning of MSD II. Using the 3 week plan template, the following are tasks we aim to complete to help us achieve this vision:

Brandon:

Brent

Alex

Shahzain

Liam

(Use the individual 3-week plan template for this)


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