P13601: Titania Nanotube Reactor
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Build, Test, Document

Table of Contents

Addressing the key issues presented from the previous model the new modeled system is equipped with a better container, a system for uniform solution, and remote control. The container will be tested if the humidity within is less than 15% relative. The magnetic stir will be tests on the constraints of the water bath system dimensions, and to provide a uniform mixture. The electrode spacing will provide the required distance testing between the Platinum and Titanium electrodes. The Chiller unit will be tested to see the difference of temperature between that of the solution and those of the chiller.

Below is the final assembly of the new system.

Specifications

Build&Test/msd spec.pdf

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Build&Test/msd spec.xlsx

Click the above link to download the Excel

Schedule

WorkingDocuments/Senior Design Schedule-1_NE MSDII.xlsx

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Build, Test, and Integrate

Iterative activities to validate functionality and performance at the sub-system and system level.

Prototype Reactor

The above figure is the prototype of the reactor vessel that will have the water bath circulation. The plastic cup will go inside the vessel and create a seal that will keep the water within the vessel while transferring heat to-or-fro as designed.

Magnetic Stirrer

Figure 1: Setup of testing magnetic stir
public/Photo Gallery/Build Stirr.jpg

Place the prototype vessel with interior cup inside on top of the Stir Plate and started the test. The test was a success, the magnetic stirrer caught the magnetic field and stirred the solution as designed from the feasibility test parameters. For further analysis of the test please refer to the Magnetic Stirrer Test.

Chiller Parameter

Figure 2: Setup of testing Chiller Parameter

The above image is the testing setup for the chiller parameter. The chiller is placed below due to not having a pressure difference within the vessel, so utilizing gravity the circulating fluid is brought back to the unit. Please refer to the Test Plans & Test Results for the performance results.

Spacing of Electrodes

Figure 3: The construction CN 1

The above figure illustrates the construction and ingenuity to hold the electrodes in place with accordance with CN 1. The three holes to the right is to hold the entire accessory onto the mount. On the left side, the single hole is for the primary electrode, Platinum. The slits are for the Titanium electrode(s) and this will provide the varying distance as requested by CN 1. Please refer to Testing and Results for further analysis.

Humidity and Environment control

Figure 4: Building of the environment control

The above figure illustrates how we are going to control the humidity by purging the space with dry air. There are neoprene rubber placed around the edge of the front door to create a seal that will prevent any leakage of air out and prevent any water to enter.

Labview Testing

Figure 5: Labview Window

Once the overall code is written, the program was integrated with the physical assembly and was tested to see if labview could control all the parameters. Please refer to Labview Debuggin for further analysis and the Labview code that was used.

Test Plans & Test Results

This section will provide the results and conclusion of each components of the new system in regards of the Customer Needs (CN)

Chiller Parameter

Addressing CN 5: Ability to control electrolyte temp between 0-70oC, within 0.5oC of target. Table 1: Results of Chiller Parameter and duration of change Table 2: Set points of the Chiller when heated/chilled
Heat Chill
Chiller Reactor Chiller Reactor
Temperature (deg C) 22.04 19.70 24.98 19.39
Start Time 1:09 pm 9:30 am
Set Point 1 (deg C) 26.00 24.98
Set Point 2 (deg C) 55.20 7.20

First thing to note is that the heating and the cooling portion were done on two separate days, the time to each other are irrelevant. The highlighted lines is when the system achieved steady state at first set point. We needed to establish a first setpoint to see how long the unit will take to change from the first setpoint to the second. This would provide an accurate reading that can be implemented on the program. This test was ran without a heat source produced by the electrodes but from previous data the spike of temperature change is not important since the spike is within a span of a couple of minutes. The more important aspect was the steady state capabilities.

This test was to see how close the chiller and the vessel temperatures differed relative to the second set point and if the vessel can hold steady state as customer required.

TestandResults/Chiller Test Results.xlsx

Click the above link to see the excel data spreadsheet for the chiller parameters.

Magnetic Stirrer Test

Addressing CN 6: Maintain a well mixed electrolyte Figure 6: Magnetic Stirrer Test The magnetic tablet will start to turn when the level setting is set at around 1. The maximum speed the stirrer can function properly is around 4 to 5 level setting. The level 3 setting was the best option for the water was being stirred well without agitating the water to the point where it will disturb the electrodes. The downfall of the setup seems to be that if the stirrer was interrupted or the reactor was bumped the stirrer becomes out of line from the magnetic field.

Testing Spacing

Addressing CN 1: Ability to vary spacing between electrode: 1-5cm Addressing CN 2: Ability to fabricate two simultaneous nanotube samples per reaction in the range of 1-3cm to 3-4cm.

Figure 7: Spacing Test Setup

public/Photo Gallery/Test Spacing.jpg
Placed the primary (Platinum) electrode in the center hole and placed the opposite electrode (Titanium) electrode first in the center slit. The closest spacing for the center was measured to be 3.50cm, and the farthest spacing for the center was measured to be 5.10cm. For the wings slits the electrodes would be slightly tilted to have majority of the flat surface exposed there the measurement was taken from the center of the electrodes. The wings of the slits, closest spacing was measured to be 1.20cm and the farthest spacing was measured to be 4.85cm.

Testing Leakage

Addressing CN 10: Ability to maintain relative humidity below 15% Addressing CN 16: Allows visual inspection of reactor chamber.

Figure 8: Testing leakage

public/Photo Gallery/Test Leakage.jpg

The above figure illustrates how we tested the leakage of the container. All the holes were blocked and we pumped dry air into the container. We took a squirt bottle and sprayed water along the edges twice to see if the water was being pushed in the opposite direction or if there were bubbles forming. Along the sides of the container there were no leakage. There are however 4 points of failure.

Table 3: Points of failure with the container
Position Location Amount
1 Front Panel Top hinge Leaking on top and bottom of the hinge
2 Front Panel Bottom hinge only the bottom of the hinge
3 Front panel Right Edge Towards the middle of the neoprene there is a miniscule amount of leakage
4 Front panel Top Edge There is a slit between two neoprene sealant

Testing Humidity

Addressing CN 10: Ability to maintain relative humidity below 15%

Figure 9: Humidity Tester

The figure on the left is the equipment (Psycrometer) that we used to test the humidity within the container with and without a water source within. The figure on the right is the full assembly including the Psycrometer to acquire the humidity readings.

Table 3: Results of the humidity tests with and without a water source

The above table shows the relative humidity within the system at different dry air flow rates to see the time it take to reach a low point. The table to the right is the results with a water source present in the system. Since we addressed the extremes of the flow rate there was no need to test the flow at varying rates. We wanted to observe the equilibrium state of the system and the amount of humidity.

Labview Debugging

Addressing CN 9: Measure and display temperature, voltage, current
Addressing CN 8: Ability to operate at currents between 100 microA - 5A
Addressing CN 7: Ability to control voltage between 0-100V, and maintain within 0.05V of target.

Overall program to operate the reactor: Build&Test/Labview/Labview Reactor without Chiller/User Reactor Labview_no chiller.vi

SubVI for measuring current (must be downloaded for overall program to work): Build&Test/Labview/Labview Reactor without Chiller/MeasureCurrent_ no chiller.vi

SubVI for controlling voltage (must be downloaded for overall program to work): Build&Test/Labview/Labview Reactor without Chiller/Wait for power supply_no chiller.vi

Due to time constraints, technical difficulties communicating with the chiller via computer, and complexity of a SubVI that needs to be created for the chiller, the task of controlling the chiller via LabVIEW was not able to be completed. Below, the VI and SubVIs have been provided for what has been started to complete the task of controlling the chiller.

Overall program to operate the reactor: Build&Test/Labview/Labview Reactor with Chiller/User Reactor Labview_Chiller.vi

SubVI for measuring current (must be downloaded for overall program to work): Build&Test/Labview/Labview Reactor with Chiller/MeasureCurrent_Chiller.vi

SubVI for controlling voltage (must be downloaded for overall program to work): Build&Test/Labview/Labview Reactor with Chiller/Wait for power supply_Chiller.vi

Final Tests

Table 4: Initial conditions of final test

This was the initial conditions of the final product test. The solution of the reactor was a used solution that was provided by the customer.

Figure 10: Current during the reaction

Figure 10 shows that within the reactor there was little to no current passing through even though the voltage was set at 60 volts. The data shows that the voltage never changed.

Figure 11: Temperature of the Solution

The above figure shows the temperature of the solution being held constant. The sudden spike of temperature, around 2000 secs, was expected from previous data , but the most important aspect of this test is that the temperature was held constant. The deviation of temperature was also expected, please refer back to chiller's parameter test, where the difference of solution to chiller was about three degrees.

Figure 12: Result of the Titanium Electrode

The image above depicts the final test results. The metallic strip on the left is an old sample created with the previous model. The metallic strip on the right is the new sample used with the new model. When compared, the key difference are noticed. The old sample shows a lot of rings and strong discoloration and is very uneven. The new sample show the same discoloration but does not show a large variety as the old sample. This observation helps conclude that the new system with the precisely controlled environment yields a completely different result.

TestandResults/Final Test Run Experiment 1.pdf

Click the above link to view the data.

TestandResults/Final Test Run Experiment 1.xlsx

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Assembly Instructions

WorkingDocuments/Assembly Instructions.pdf

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WorkingDocuments/Assembly Instructions.docx

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User or Operator Instructions/Manual

WorkingDocuments/User Manual.pdf

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WorkingDocuments/User Manual.docx

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Service Instructions/Manual

WorkingDocuments/Service Manual.pdf

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WorkingDocuments/Service Manual.docx

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Future Recommendations

Due to a time constraint these are some feature that were not implemented, however the customer did not request. If the following were added later this will potentially be a better design than the current design created.
  1. Create a larger chamber: Have more room so the user can comfortably maneuver within the chamber
  2. Link the Chiller unit remotely through LabVIEW: Have all the system parameters localized within one program instead of two different programs.
  3. Add an external coupling to the chamber: This is a design concept that will allow the user to move the chamber by only removing tube that are on the exterior instead of complete disassemble.
  4. Clamping system for the beaker: add a clamp that will hold the beaker down if the pump speed needed to be varied.
  5. A humidity detector: a link between a humidity detector to have recorded live data
  6. Dry air flow regulator

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