2020-05 Tank opening report
Date
2020/05/27 00:00to 2020/06/18 00:00
Attendees
- @piekie@helsinki_fi
- @httyrvai@helsinki_fi
- @mimanner@helsinki_fi
@mention a person to add them as an attendee and they will be notified.
Goals
- Repair the broken belt recharging system and related issues
- Replace the apparently broken white belt with a new green one
Motivation for tank opening
Time | Item | Who | Notes |
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2020/05/27 00:00 | Failure report |
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2020/05/27 00:00 |
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2020/05/27 00:00 | Asentotieto potikka toimii normisti ja lineaarisesti. Jännitteen säätö ei. Läpilyötejä tulee heti ja paljon kun RsCh-V nousee yli mainitsemani kuuden kilovoltin. Kiihdyttimellä ei pysty tällähetkellä ajamaan edes AMS- ajoa luotettavasti. | ||
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Jos kaskadi paska ...Onko varakaskadi tai sen komponentteja saatavilla? | |||
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Näkyykö hihnassa jälkiä kun kurkkaa pikkuikkunasta ja pyörittelee hihnaa uuteen asentoon? | |||
Hihnaa ei saa pysähtymään läpilyöntijäljen kohdalle kuvausta varten (aina pitää tehdä starttikierros, kun hihnan käynnistää), mutta varmahko | |||
Katsottiin ikkunasta eikä jälkiä näkynyt. Ei sisä eikä ulkopuolella. Ei kyllä pyöritelty asentoa, eli vain yhdestä kohtaa katsottiin. Eilen katsoin hihnan käydessä, eikä silloinkaan näkynyt mitään. Tosin pyörivästä hihnasta ei tietysti näe pieniä jälkiä. | |||
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Close-up photos of the broken belt
The black traces are electrically conducting material, and apparently the belt lost its essential properties! The photos are from the outer surface, the inner surface is smoother and carries the charge.
Action items
Tankin kaasu on pumpattu varastosäiliöihin ja tankkiin pumpattu tyhjiö (25mbar) 2020/05/27 00:00 @kmizohat@helsinki_fi. Aloitin ilmaamisen juuri äsken. Eli mitä tähän asti on tehty ja mitä Pietari ehkä tekee huomenna on tässä alla.
Gas transfer from EGP to S1 and S2, 2020/05/28 00:00 @piekie@helsinki_fi
* Compressor stopped at temperature of 40C of the output side about 40C. (Compressor stopped automatically after finishing gas pumping (~-0.45bar from automation system), but restarted for cooling compressor (valves to storage tanks closed, V24 opened).
Add more detailed steps to gas transfer guide (use of compressor part, opening of few valves etc.) @ptikkane@helsinki_fi 2020/06/02 00:00
Vacuum pumping of EGP pressure tank 2020/05/28 00:00 (Start: 15:00, stop: 17:00). End pressure ~25mbar at K3 platform. (@piekie@helsinki_fi @kmizohat@helsinki_fi )
Venting EGP pressure tank 2020/05/28 00:00 @kmizohat@helsinki_fi
Ventilation of EGP pressure tank and installation of ventilation blowers 2020/05/29 00:00 @piekie@helsinki_fi
Opening of service holes, installation of the service lift components 2020/05/29 00:00 @piekie@helsinki_fi
Order a new green Siegling belt from Transpap 2020/05/28 00:00 @ptikkane@helsinki_fi
Installation of the charging belt @piekie@helsinki_fi @mimanner@helsinki_fi 1-4 Jul 2020
Regeneration of the gas drying absorber with dry N2 @httyrvai@helsinki_fi 2020/06/03 00:00
Order BIOGON C, a set of 12 x 50 L bottles of CO2 (360 kg) from Linde Gas @ptikkane@helsinki_fi 2020/06/02 00:00
Adding of CO2 to S1/S2 during the gas transfer back to EGP tank @httyrvai@helsinki_fi (CO2 must be diluted with N2 before pumping with the compressor!)
Checking of charging system inside HV-terminal and tank-bottom. Plates adjusted to 8.0 mm at receiving side, 5.0 mm at leaving side. Was equal previously. No need to adjust brushes ( spare brush material was found yesterday, we have plenty ) Pietari Kienanen 2.5.2020
Add guidelines for the regeneration of the gas dryer @ptikkane@helsinki_fi 2020/06/02 00:00
Add guidelines for adding N2 and CO2 @ptikkane@helsinki_fi 2020/06/03 00:00
Add guidelines for drying the insulating gas @ptikkane@helsinki_fi 2020/06/04 00:00
Test the recharging chain: control rod mechanism, variac(s), HV-cascade @httyrvai@helsinki_fi 2020/06/04 00:00
RsCh components were tested in the electrical lab and an effort to optimise the RsCh-chain was taken by reducing the cascade components and leaving the step-down transformer from the system. How ever the result was unsatisfactory and we were forced to rebuild the system as it was earlier. The faulty step-down transformer was replaced with a new one. @mimanner@helsinki_fi @httyrvai@helsinki_fi 6.6-9.6.2020
Testing of the HV-terminal and components lowering of the terminal dome @piekie@helsinki_fi @httyrvai@helsinki_fi @mimanner@helsinki_fi 10.6.2020
Ch-component testing and adjustment. @httyrvai@helsinki_fi @mimanner@helsinki_fi @piekie@helsinki_fi 10.6.2020
Shortcut test OK. Plates in the tank bottom were adjusted to 6.0 mm at receiving side, 4.5 mm at leaving side. Spark cap inside the tank has to be adjusted relatively open (3.0mm) for the shortcut test. @mimanner@helsinki_fi @piekie@helsinki_fi 15.6.2020
Adjustment of the Spark cap inside the tank to the operating pressure ( 0.8mm ), and cleaning of the tank bottom floors. @mimanner@helsinki_fi @piekie@helsinki_fi 15.6.2020
Service lift components removal and closing of the service holes. @piekie@helsinki_fi 15.6.2020
Drying Gas with belt running 16-18.6.@HT
Tank opening completed 16:30. 2020/06/18 00:00 Final pressure 10.2 bar. Dewpoint -58.9. HT
Tandem ready for AMS. Starting measurements 2020/06/22 00:00. All OK, charging/recharging working much better now, requiring less voltage, 6-7 kV instead of 10 kV required before.
Fault diagnostics
- Belt apparently broken, this explains the mysterious behaviour to some extent. But note that we have observed belt broke as a result of tank sparks also earlier, with both thick HVEE seamless belts and with the green Siegling belt (in 2004 to 2006). Or as a result of recharging system gone wild!
Monday2020/06/01 00:00
Terminaali on nyt nostettu ja Mikko poistaa välitankoja paraikaa.
aistinvarainen tarkistus terminaalin komponenteille, eikä mitään poikkeavaa havaittu:
varauksenvaihtolevyt olivat tiukasti paikoillaan
- karvat olivat kontaktissa
- palaneen hajua ei ollut havaittavissa
- RsCh säätö vastus ja sen kanssa sarjassa oleva kiinteä muuntaja olivat ehjän näköiset ja hajuiset
- Wednesday2020/06/03 00:00
- The recharging system still doesn't work as expected after replacement of the belt, re-ch voltages sky-rocketing to 25 kV! The whole chain must be tested externally on test bench.
- Poor and intermittent contacts at the re-ch variac. Perhaps OK after service & cleaning.
Thursday 2020/06/04 00:00 1.
Cascade + variac's OK, tested with 400 Hz gen.
Service/repair of electronics in terminal very difficult, small parts squeezed into one shield box. Danger of braking PI-filters. Must design a new shielded box.
- Friday 2020/06/05 00:00
Testing of step-down transformer. A new one 230/35 VAC from Farnell to get max 20 kV from cascade.
- The trial with modifying the cascades was not succesful, ripple increases with less stages connected. Must keep the step-down transformer.