Rapid Pneumatic Transport of Radioactive Samples.
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Transcript of Rapid Pneumatic Transport of Radioactive Samples.
Rapid Pneumatic Transport of Radioactive Samples
Why?
• This system can be used to transport radioactive samples quickly and safely from an activation site to a counting station.
• For example: transporting neutron activated graphite discs from the reaction chamber to a counting station.
Design of the Prototype SystemRaPTORS version 1.0
• The first design used a pull-pull vacuum system
ReactionStation
CountingStation
VacuumBlower 2
VacuumBlower 1
ReactionStation
CountingStation
VacuumBlower 2
VacuumBlower 1
• Both Blowers turn on to aid in the initial lift of the carrier
Design of the Prototype System
ReactionStation
CountingStation
VacuumBlower 2
VacuumBlower 1
• Carrier lifting stage
Design of the Prototype System
Design of the Prototype System
ReactionStation
CountingStation
VacuumBlower 2
VacuumBlower 1
• After a predetermined amount of time, the first blower turns off, allowing the second blower to pull the carrier through the rest of the system
Design of the Prototype System
ReactionStation
CountingStation
VacuumBlower 2
VacuumBlower 1
Design of the Prototype System
ReactionStation
CountingStation
VacuumBlower 2
VacuumBlower 1
• After the carrier passes the second blower there will be little to no suction on the carrier because the blower itself is open to the atmosphere
Design of the Prototype System
ReactionStation
CountingStation
VacuumBlower 2
VacuumBlower 1
• As the carrier falls it is de-accelerated by compression
Design of the Prototype System
ReactionStation
CountingStation
VacuumBlower 2
VacuumBlower 1
• Vacuum blower 2 turns off
Design of the Prototype System
ReactionStation
CountingStation
VacuumBlower 2
VacuumBlower 1
• Valve opens, Carrier drops
Design of the Prototype System
ReactionStation
CountingStation
VacuumBlower 2
VacuumBlower 1
Construction of the RaPTORS Prototype System
Construction during the summer of 2005
Construction of the RaPTORS Prototype System
Construction team
Components4” diameter PVC pipe
2 end stations 4 vacuum-blowers
Carrier
Tour
Carrier starts in the activation station
Vacuums turn on and carrier is propelled pneumatically into the system via 4” smooth bore PVC pipes
The carrier leaves and enters the end
stations
Reliability Tests (experiment #1)
Reliability Tests
• 1,100 trials in both directions
• ~114 ft (34.7 m) end station to end station
• Ten 90º turns
• 4 out of plane turns
• 250,800 feet ~ 47.5 miles were covered in tests
Average Speed through System ( 2x2 vacuums)
5.8
6.0
5.50
5.60
5.70
5.80
5.90
6.00
6.10
R→C C→R
Direction of Flow
Sp
eed
(m
/s)
Sealed carrier
C→R = traveling from the counting station to the reaction chamberR→C = traveling from the reaction chamber to the counting station
System Speed Test (experiment #2)
Average Speeds of System
Ventilation
• At the NIF the nitrogen in the air will be activated• It will be necessary to isolate the air in the
system near the reaction chamber from the air in the counting station
• This will include venting the air inside the carrier as well
• Venting the carrier will be accomplished by blowing air through holes that have been placed in a standard carrier
Sealed vs. Vented Carrier
Sealed carrierVented Carrier with 18 holes
VELoCIRaPTORS 2.0Sealed vs. Vented Carrier
• VELoCIRaPTORS will be the RaPTORS system with a special venting station included
• To prepare for VELoCIRaPTORS, various speed tests were designed to compare the speed of a sealed carrier to a vented carrier. These measurements were used to determine the degree of drag on the vented carrier.
• Several carrier ventilation configurations were used in these tests.
VELoCI=Venting and Exhausting of Low Contaminant Internal Gasses
Variables to be Tested• Number of holes in carrier
• Number of vacuum-blowers connected to system
Average Speed Through System
• The first benchmark was to measure the time it took for a carrier to move through the whole system
• An average speed of travel for the entire system was derived from these times
Speeds for Different Number of Holes (2x2 vacuums)
5.9
5.75.6 5.6
6.0
5.85.7
5.7
5.0
5.2
5.4
5.6
5.8
6.0
6.2
6.4
0 6 12 18
Number of holes
Sp
eed
(m
/s)
C → R
R → C
Results
C→R represents counting station to reaction chamberR→C represents reaction chamber to counting station
Results
Speeds for Different Number of Vacuums
2.8
5.0
5.86.1
0
1
2
3
4
5
6
7
1 2 3 4
Number of Vacuums Pulling on the System
Sp
eed
(m
/s)
Carrier with 18 holes, traveling C→ R
C→R represents counting station to reaction chamberR→C represents reaction chamber to counting station
Pressure Tests (experiment #3)
Pressures in System
Pressure Tests
• It was hypothesized that there would be a measurable pressure change as the carrier passed a gas pressure sensor while traveling through the system. If true, this would present a way to determine the position of the carrier in the system if it were to become jammed.
Sensor Points
1
2
3
Pressure TestsPlastic tube flush to the inside of the pipe
Plastic tube connected to Gas Pressure Sensor
Computer
Johnson strip connected to ADC
Program run in LabView
Pressure Tests
• Noise reduction was achieved when the sensors were placed close to the computer. This minimized the signal cable length from the sensor amplifier to the ADC. Placement of the amplifier required the use of 50 feet of polyethylene tubing.
Pressure Tests
• The following graphs were created by averaging each data point with the 5 closest points to it and then plotting the ratio of the average from one sensor to the corresponding average of one of the other sensors.
Pressure Ratios as the Carrier Moves Past Pressure Sensors from Sensor 3 to 1 (Bottom to Top)
0.98
1
1.02
1.04
1.06
1.08
1.1
Time
Pre
ss
ure
:Pre
ss
ure
ratio avg 2:1
ratio avg 3:1
ratio avg 3:2
Each peak represents when the carrier passed by one of the sensors creating a measurable difference between the pressure at the sensor that was passed and the other sensors.
Results
Results
Pressure Ratios as the Carrier Moves Past Pressure Sensors from Sensor 1 to 3 (Top to Bottom)
-0.02
-0.015
-0.01
-0.005
0
0.005
0.01
0.015
0.02
Time
Pre
ssu
re:P
ress
ure
ratio avg 2:1
ratio avg 3:1
ratio avg 3:2
It is supposed that as the carrier travels up this vertical section of pipe, it is slowed by gravity enough that a pressure build-up occurs, which in turn draws it up the pipe, resulting in measurable changes in pressure between the sensors. When the carrier is traveling in the opposite direction, down this section of pipe, it falls freely and no measurable pressure differences arise.
Conclusions of Pressure Tests
• The carrier is believed to move through most of RaPTORS by flow, as if dropped into a river, and not by pressure changes.
• Tracking the pressure throughout the system would not be helpful in determining where the carrier was between the end stations.
Local Speed Tests (experiment #4)
Point to Point Speeds
• Further speed tests were designed to measure the speed of a carrier as it passed through certain characteristic sections of the system (e.g. 90° turns, straight aways, etc.)
• Photogates were used to accumulate this information.
Speed Tests
Sensor A
Sensor B
Sensor B
Sensor C
Oscilloscope
AB
C
DLight Sensors in photo resistor
circuits
Circuit board
LED light received by sensor until carrier passes
ResultsBottom Turn (B↔C)
1.2
3.5
4.95.4
6.5
7.8
1.0
4.1
5.26.1
7.9
9.5
0.0
2.0
4.0
6.0
8.0
10.0
12.0
1x1 up 1x1 down 2x2 up 2x2 down 3 4
Number of Vacuums
Sp
ee
d (
m/s
)
Vented Carrier
Standard Carrier
ResultsTop Turn (C↔D)
1.7
3.94.6
6.1 6.2
7.3
2.2
4.15.0
6.5 6.9
8.4
0.0
1.02.0
3.0
4.05.0
6.0
7.08.0
9.0
1x1 up 1x1dow n
2x2 up 2x2dow n
3 4
Number of Vacuums
Sp
eed
(m
/s)
Vented Carrier
Standard Carrier
Results
Vented Carrier
3.7
1.21.7
6.8
4.9 4.6
9.4
6.5 6.2
10.7
7.8 7.3
0.0
2.0
4.0
6.0
8.0
10.0
12.0
A→B (straight meter) B→C(Bottom Turn) C→D (Top Turn)
Position
Sp
eed
(m/s
)
1x1 2x2 3 4Blower-vacuum configuration
Results
Standard Carrier Speeds
3.7
1.02.2
7.1
5.2 5.0
10.5
7.96.9
12.3
9.58.4
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
A→B (straight meter) B→C(Bottom Turn) C→D (Top Turn)
Position
Sp
eed
(m/s
)
1x1 up 2x2 up 3 4
Maximum speed achieved = 12.3 m/s
~ 28 mph
Blower-vacuum configuration
Conclusions from Speed Tests
• From the speed tests preformed, it has been decided that putting a vented carrier through the system results in negligible speed loss
• A venting station has been designed to be used mid-journey to remove the air from the system
• The removal of the air will protect the lab technician operating the counting station
Venting Station
Gate Valve
VacuumBlower
Pressure Blower
Gate Valve
Carrier
To rest of system
To rest of system
BrakingLength
Components of the Station
• The central piece will be a 4-way pvc-pipe junction
• Gate valves will be used to block off sections of the pipe in order to both direct the carrier as well as air flow
• The carrier will compress the air in a long section of pipe that will act as a braking system for the carrier
VacuumBlower 3
Gate Valve
Carrier
BrakingLength
ReactionStation
CountingStation
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
VElociRaPTORS version 2.1
VacuumBlower 3
Gate Valve
Carrier
BrakingLength
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
CountingStation
ReactionStation
VElociRaPTORS version 2.1
• 2 Vacuum Blowers for initial lift
VacuumBlower 3
Gate Valve
Carrier
BrakingLength
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
CountingStation
ReactionStation
VElociRaPTORS version 2.1
• Carrier lift phase
VacuumBlower 3
Gate Valve
Carrier
BrakingLength
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
CountingStation
ReactionStation
VElociRaPTORS version 2.1
VacuumBlower 3
Gate Valve
Carrier
BrakingLength
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
CountingStation
ReactionStation
VElociRaPTORS version 2.1
• Blower 1 turns off
VacuumBlower 3
Gate Valve
Carrier
BrakingLength
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
CountingStation
ReactionStation
VElociRaPTORS version 2.1
• Carrier Triggers Photogate
VacuumBlower 3
Gate Valve
Carrier
BrakingLength
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
CountingStation
ReactionStation
VElociRaPTORS version 2.1
• Blower 3 turns off • Carrier is slowed by compression
VacuumBlower 3
Gate Valve
Carrier
BrakingLength
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
CountingStation
ReactionStation
VElociRaPTORS version 2.1
• Gate Valves reposition
VacuumBlower 3
Gate Valve
Carrier
BrakingLength
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
CountingStation
ReactionStation
VElociRaPTORS version 2.1
• Blower 3 pulls carrier back to venting position
VacuumBlower 3
Gate Valve
Carrier
BrakingLength
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
CountingStation
ReactionStation
VElociRaPTORS version 2.1
VacuumBlower 3
Gate Valve
Carrier
BrakingLength
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
CountingStation
ReactionStation
VElociRaPTORS version 2.1
• Blowers 3 and 4 vent carrier
VacuumBlower 3
Gate Valve
Carrier
BrakingLength
ReactionStation
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
CountingStation
VElociRaPTORS version 2.1
VacuumBlower 3
Gate Valve
Carrier
BrakingLength
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
CountingStation
ReactionStation
VElociRaPTORS version 2.1
• Gates reposition again
VacuumBlower 3
Gate Valve
Carrier
BrakingLength
ReactionStation
CountingStation
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
VElociRaPTORS version 2.1
• Blowers 2 and 4 pull and push respectively
VacuumBlower 3
Gate Valve
Carrier
BrakingLength
ReactionStation
CountingStation
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
VElociRaPTORS version 2.1
VacuumBlower 3
Gate Valve
Carrier
BrakingLength
ReactionStation
CountingStation
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
VElociRaPTORS version 2.1
• Carrier is slowed by compression
VacuumBlower 3
Gate Valve
Carrier
BrakingLength
ReactionStation
CountingStation
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
VElociRaPTORS version 2.1
VElociRaPTORS version 2.1VacuumBlower 3
Gate Valve
Carrier
BrakingLength
ReactionStation
CountingStation
Pressure Blower 4
Photogate
VacuumBlower 1
VacuumBlower 2
• Gate valve opens to allow carrier to fall
RaPTORS version 2.0
• The new system will allow venting of air inside the carrier as well as inside the pipe
• A push-pull method will be implemented to increase performance
• RaPTORS will provide a swift, safe method for transporting radioactive samples