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