ALICE

Recovering the cryogenic system from major

contamination

ALICE

• Energy Recovery Linac

• 2 x 1.3GHz 9 Cell SCRF Modules

• Operating temperature - 2K

• Pressure stability ± 0.1mbar

Cryogenics Plant• Linde TCF50

Liquefier• 1500 Litre Dewar

(Wessington Cryogenics)

• Linde 2K Recouperator

• Leybold Ambient Pumps

• Transfer Lines manufactured by DEMACO

Breox Oil!!!!

• Historical oil contamination from Breox oil

• Formaldehyde Contamination• Changed to CPI 4601-46 in 2009

DICC Installation

Contamination – Part 1

Contamination – Part 1

Contamination – Part 1Fit Pressure

Gauge

Fit Pressure Gauge

Contamination – Part 1

• Adsorber replaced October 2013

• Evidence of oil and carbon dust found on Hx E3110

• Solvent flush performed on E3110

Contamination – Part 2

• Feb 2014 Liquefier inoperable again!!• Heated Nitrogen purge at 100°C• Oil found from purge!!!!• New adsorber now contaminated

with oil??• Decided to remove the adsorber and

replace with pipework.

Contamination – Part 2

• March 2014 Liquefier opened to remove adsorber.

• Adsorber constructed from carbon pellets with a coarse mesh filter and Rockwool discs.

Contamination – Part 2

Contamination – Part 2

Contamination – Part 2

• Visited Linde June 2014• X-ray tests of faulty adsorber

inconclusive• Adsorber cut open for inspection

Contamination – Part 2

Contamination – Part 3

• July 2014 Capacity of the 2K system started to reduce

• Instrumentation failures• 2K pumps trips due to low oil level• Unable to maintain pressure stability

so forced to shutdown for repair

Contamination – Part 3

• Oil drained and Recouperator box cleaned.

• U-bend estimated to have contained at least 10 litres of oil.

• Still had persistent pressure drop in 4K box – Hydrocarbon from Compressor!!!!

Repair

• September 2014 started repairs.

• All oil contaminated pipework cleaned with Petroleum Ether.

Repair

Conclusions

• Find and fix your leaks.• Test as much of your new equipment

off-line.• Service your equipment regularly.• Don’t Rush!!!

Thanks!

• Hermann Herzog and his team from Linde Kryotechnik

• Wilhelm Vorbuchner – Cryvotech