Purifier Vacuum Jacket Pump Out --------------------------------- Revision Date: 10-Aug-2023 This note is about the pump out of the vacuum jacket on the Purifier that was done on 5,6,7 -Aug-2023. The Purifier last worked OK on Wednesday 2-Aug-23. There was no gas to liquefy on Thursday 3-Aug-23. There was gas to liquefy on Friday 4-Aug-23 and Saturday 5-Aug-23 but the Purifier would not run. The Purifier just went through a series of "Regenerate" cycles and always failed to get cold enough to start providing purified gas. Each of these cycles took about 12 hours. Saturday 5-Aug-23 was 120 days since the previous Purifier Vacuum Jacket Pump Out. Sat 5-Aug 22:15 Mode 35 122k 79k 31 psi 31 psi 227 psi of recovery gas 23:45 Purifier OFF via LCD OFF button Connect the Vacuum Pump Cart to the Top and Side Jacket Pump Out Ports and Open the Ports. 23:55 167k 117k 47 psi 47 psi 8.3 e-3 3.2 e-2 off torr Sensors 1,5,6 Start the Turbo pump External Heating Varic 50 Volts Sun 6-Aug 00:15 169k 121k 47 psi 47 psi 1.1 e-2 7.3 e-4 6.6 e-5 torr Turbo pump at full speed External Heating Varic 50 V 13:45 218k 198k 47 psi 47 psi 5.2 e-3 8.0 e-4 1.4 e-5 torr I want to get the Purifier fully warmed up and to pump on its Cold Trap so touch LCD Panel Regenerate the Purifier moves to Mode 51, both internal heaters come ON and it vents down to 9 psi 9 psi 14:00 8.0 e-3 1.2 e-3 1.2 e-4 torr This is about the highest that the pressures got after turning ON the internal heaters. I think that I saw a peak as the Cold Trap came through zero deg C Mode remains 51 15:00 4.8 e-3 7.6 e-4 5.1 e-6 torr Still Mode 51 "Warm Up for Regenerate" 286k 300k 22 psi 22 psi The Cold Trap temperature was as high as 311k but now appears to be regulating at about 300k Both internal heater still ON = Green External Heating Varic 50 Volts. 21:30 4.6 e-3 7.9 e-4 2.5 e-6 torr Still Mode 51 "Warm Up for Regenerate" 297k 297k 22 psi 22 psi Get the purifier to move from Mode 51 to Mode 71 by touching LCD ON then touch LCD Regenerate. I have the purifier set for a 24 hour Regenerate cycle. 21:40 4.6 e-3 7.9 e-4 2.5 e-6 torr 297k 297k -14 psi -14 psi Mode 71 The Cold Trap is being pumped. Mon 7-Aug 9:15 4.5 e-3 8.1 e-4 2.9 e-6 torr 299k 298k -14 psi -14 psi Mode 71 Close the Vacuum Jacket Ports and disconnect the Vacuum Pump Cart. Touch LCD OFF, Wait 5 sec, Touch LCD ON This moves the purifier to Mode 11 "Cool Down" I put the white box with the special vacuum fittings for the purifier in the White Cabinet in the sub-basement by the Recovery Tanks. This cabinet is labeled, "Helium Recovery System Parts - Do Not Touch Unless You Are Reza Loloee". 9:20 299k 298k 32 psi 32 psi Mode 11 Start Cool Down 11:30 246k 187k 32 psi 32 psi Mode 11 Cooling Down 12:30 220k 146k 32 psi 32 psi Mode 11 " " 13:30 198k 109k 32 psi 32 psi Mode 11 " " 14:30 178k 80k 32 psi 32 psi Mode 11 " " 16:00 104k 53k 32 psi 32 psi Mode 41 Normal Production This was a nice fast cool down. But the pressure in the Liquefier Cryostat remains at 0.25 psi. No gas is getting to the Liquefier Cryostat. Must leave. 22:40 The problem was that the input gas pressure regulator was set to zero. Turn it up to the normal 3 psi. 22:45 73k 61k 32 psi 31 psi Mode 41 Liquefier is getting gas 23:15 79k 56k 31 psi 31 psi Mode 41 Tues 8-Aug 9:15 81k 57k 32 psi 31 psi Mode 41 Liquefier making liquid End of pump out process. Analysis: We had built up about 250 psi of gas in the Recovery Tanks so we have the chance for a nice continous and long run of the Liquefier which gives us a chance to measure how well it is working. Everything was operating in a stable way during the following long run, no Liquid Helium was extracted, and the Liquefier cryostat was right at 3 psi the whole time. The raw data is: Mon 7-Aug 23:10 40.2 liters 254 psi in recovery tanks Tu 8-Aug 9:15 50.0 193 17:15 58.9 199 a bag full had been pumped into recovery tanks Wed 9-Aug 9:15 78.3 103 17:15 88.2 84 some gas had been pumped into recovery tanks 22:45 94.5 51 From the adjacent pairs of raw data you can calculate: Liquid Rcv Liters PSI Helium Tnk Delta Delta Delta per per Date and Time Liters PSI Time Liters PSI Hour Liter ----------------- ------ --- ----- ------ ----- ------ ----- Mon 7-Aug 23:10 40.2 254 10.1 9.8 61 0.97 6.22 Tu 8-Aug 9:15 50.0 193 8.0 8.9 * 1.11 * 17:15 58.9 199 16.0 19.4 96 1.21 4.95 Wed 9-Aug 9:15 78.3 103 8.0 9.9 ** 1.24 ** 17:15 88.2 84 5.5 6.3 33 1.15 5.24 22:45 94.5 51 * --> a full bag of gas had been pumped into the recovery tanks ** --> some recovered gas, less than a full bag full, had been pumped into the recovery tanks The full run delta time is: 47.6 hrs The full run delta liters is: 54.3 L ---> 1.14 Liters per Hour The average PSI per Liter for the 3 adjacent raw data pairs for which we know the delta psi is: ---> 5.35 PSI per Liter I believe that the system is rated to make 22 Liters per day ---> 0.917 Liters per Hour