7th CCT Meeting: First 310 mm Short - Mechanical Model: Loading and Cooldown operations - PowerPoint Presentation

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7th CCT Meeting:First 310 mm Short - Mechanical Model: Loading and Cooldown operations

G. Montenero, B. Auchmann, R. Felder, S. Sidorov, and Carolin Zoller: Paul Scherrer Institut

30 October 2017

SummaryPage

2

Instrumentation: Strain Gauges setup improvements

Loading and Cooldown operations

The short mechanical model

From theory to practice

Measurement results

And comparison with FEM simulations

Lesson learned

Page

3

New SGs setup on the short model

Cu D. SG@ 0°

Al.S

SG@ 0°

Al.S

SG@ 90°

Cu D. SG@ 90°

Cu D. SG@ 180°

Cu D. SG@ 270°

Al.S

SG@ 180°

Al.S

SG@ 270°

Attached 4 strain gauge bridges on the dummy coil and Al shell for better understanding of the mechanics

Solved bonding issues of strain gauges using Araldite adhesive

Better cable routing and strain management on SGs using intermediate pads for wire connections

Goals: validate mechanical design.validate manufacturing.validate instrumentation.

Short Mechanical ModelPage 4

Cu Dummy Coil

Pad/Coil Assembly

Al Shell

Iron Yoke

Bladders & Pushers

Keys (Vertical & Horizontal)

Short model assembly

And cooldown in LN2

Loading main stepsVertical Keys operation:

Vertical bladder insertion and pumping up to 200 bar Insertion of Vertical keys with no interferenceRelease of the Vertical bladders and extraction

Horizontal Keys operation

:

Horizontal bladder insertion and pumping up to 400 bar

Insertion of Horizontal keys with interference (0.55 mm shim)

Release of the Horizontal bladders and extraction

Cooldown operation

Insert the assembled model in the open ended cryostat

Cover completely the whole model assembly with liquid nitrogen

Loading and Cooldown operations

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Vertical Keys operation

Horizontal Keys operation

(LN2)

From theory to practice: What happened on the 21.12 and 22.12 -2017?Loading time line in theory

V_Blad

. In +

pump 200 bar

Start

V_Keys

Insertion

V_Blad

release and extraction

H_Blad

. In +

pump 400 bar

H_Keys

Insertion

H_Blad release and extraction

T0

T1

T1

T3

T4

T5

T6

T7~ from 2 to 3 hours

Model assembly

V_Blad

. In +

pump 200 barStart

V_Keys InsertionV_Blad

release and extractionH_Blad. In +

pump 400 barAble to insert only Right H_Keys : Mechanics has asymmetrical behavior. And at the same time pump started to leak

H_Blad release and extraction

8:35

9:24

9:46

10:03

11:04

18:30

1 Day !

Model assembly

Loading time line on the 21.01

Broken

H_Blad

H_Blad

. In +

pump 400 bar

12:43

Broken Pump

12:52

16:27

H_Blad

. In +

pump 400 bar

16:34

Broken

H_Blad

H_Blad

. In +

pump 400 bar

18:00

H_Keys

Insertion

(

but it was extremely hard to

)

18:28

From theory to practice: What happened on the 21.12 and 22.12 -2017?Cooldown time line in theory

Start

Insert the assembly into the cryostat

Cover completely the assembly with LN2

T0

T1

T2

T3~ 2 hours

Cooldown completed

Cooldown time line on the 22.01

Start

Insert the assembly into the cryostat

Cover completely the assembly with LN2

8:23

9:23

11:58

12:00

Cooldown completed

Measurement results

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Example: first 4 hours measurements on the 21.12.2017

Measurement vs. FEM simulations

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Most important step results

305 µm/m

-250 µm/m

754 µm/m

-618 µm/m

569 µm/m

-17.9 µm/m

1644 µm/m

-994 µm/m

Lesson learned

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A Better setup and an increased number of measurement points with strain gauges give confidence in the measurement results

The mechanical structure does its job but:

During loading, issues related to mechanical tolerances popped up -> asymmetric reading of the strain gauges

We need to implement a systematic quality control (measurement report) for each component that we will receive

From item 2, it is clear that we need to procure mechanical components with better tolerances (in particular parallelism between yoke and pads)

Last but not the least we need a better pump for bladder operation

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QUESTIONS ?