irradiation sample transfer line snubbing section behavior greg padilla and keane nishimoto

Irradiation Sample Transfer Line Snubbing Section BehaviorGreg Padilla and Keane Nishimoto

Introduction

BackgroundThe MIT reactor and Transfer Line

MotivationSafety measure in case of Transfer

Line failure Desired Findings

Model to help design snubbing section

Procedure

Apparatus Experimental Procedure Data Processing

ApparatusSmoothSectionW/ Bend

First Sensor

Snubbing Section

PressureSensor

SecondSensor

TransferCylinder

Transfer line

Experimental Procedure

Calibration of pressure sensor Drops at 4 heights for each of 3

different masses Data Recorded

Data Processing

Calibration data Capsule velocity calculated Pressure calculations

Typical Data from Drop Test

Data taken form container mass = 0.7kg

Height = 42” inches

Data

Trigger Trace from first sensor

Trace from second sensor Trace from Pressure

sensor

Theoretical Analysis

Model of the falling capsuleTransfer LineSnubbing Section

MATLAB Simulation

Transfer Line Model

The capsule is a falling object

Snubbing Section Model

Force due to gravity Force due to pressure

Ideal Gas Law – PV=mRTNavier Stokes

Used to determine the mass of air left

2h

hdxdP

12μ1

ρAm 3

cair

MATLAB simulation

ODE 23 solver State Variables

Position and velocity of capsuleMass of air in snubbing section

Results

Smooth Section Model

Velocity is independent of Mass Velocity is a Function of Height Velocity = 1.46*Height + 2.18 Ave. Error of 16%

Velocity as a Function of Mass

3

3.5

4

4.5

5

5.5

300 500 700 900

Mass [g]

Vel

ocity

[m/s

ec]

height=1.07 m

height=0.72 m

height=1.73 m

Exp. Data and Therical models

2

2.5

3

3.5

4

4.5

5

0.5 1 1.5 2

Height [m]

Vel

ocity

[m/s

ec]

Exp. data

Gravity Model

Snubbing Section Model

Initial Conditions: Mass = 0.7kg Velocity = 4.0m/s Temperature = 298K

Recommendations

Temp = 574K Velocity = 5.0m/s Snubbing Length

=1.5m Max P=1.81kPa Snubbing Length

=1.0m Max P=1.86kPa

Final

Temp = 574K Velocity = 5.0m/s Snubbing Length

=1.3m Max P=1.83kPa