LN2 filling system

1. Filling the buffer tank2. Filling the collector tube3. Filling the detectors4. Venting the collector tube5. Monitoring then go to 1 or 2

1. Filling the buffer tank

• Automatic?• Alarm on the buffer tank to alert operators?

2. Filling the collector tube

• Logic sequence:– Open VP – Open VIN– While FP wait for TP to get to LN2 value– Close VP

3. Filling the detectors

• Logic sequence:– (VIN already open, VP closed)– Open VDi– Wait until TVi is at LN2 temp– Close VDi

4. Venting the collector tube

• Logic sequence:– Close VIN– Open VP

5. Monitoring

• Logic sequence:– Check P,V against alarm threshold ->Step 1: Fill the buffer– Check Tdi against limit value ->Step 2: Fill all the detectors– Check time since last fill ->Step 2: Fill all the detectors

Implementation – collector

VIN

24V

NI 9476

VP

24V

NI 9476

NI 9217 NI 9425

10 – 40 V DC

NI 9217

Collector

SafetyValve(s)

NI 9476 1 + 1/column

NI 9425 1 /column

NI 9217 1 +1

24 V AC 1 +1/column

10-40 VDC 1/column

Implementation - detector

VDi

24V

NI 9476

NI 9217

Collector

SafetyValve(s)

NI 9476 1/detector

NI 9217 1

24 V AC 1 /detector

Dewar TDi

Implementation – monitoring

V

Collector

P

NI 9217NI 9425?

NI 9217NI 9425?

Dewar

Crystal

NI 9

217

NI 9

217

Custom modules

To NI 9217

To NI 9217

PTi From N

I 9476

12 V

Power On/Off

Open / Close

Opened / Closed

Powered Y/N

To NI 9425

Read PT100 Distribute valve signal Command one valve

10-40 V DC

Read flux sensors

M1 M2 M3 M4

12V

M3 working principle

12 V

Power On/Off

Open / Close

Opened / Closed

Powered Y/N

M3

12V

NI 9476

Valve

12 V

Connection diagramCompact Rio Crate (6 x NI 9217, 1 x NI 9476, 1 x NI 9425)

PT100

PT100

Prox

M1

12V

Prox

M2 M3

Valve

12V?

12V?

M4