Details

Introduction
In liquid-sodium environments, “temperature control” isn’t a comfort feature — it’s the difference between a smooth mechanism and a seized one. During IFTM (Inclined Fuel Transfer Machine) sodium testing, the parts above the roof slab are heated so that no solid sodium forms on the rails, ensuring free movement of the mechanism. At the same time, temperature‑sensitive regions (especially seals) must be kept cool to protect sealing integrity and prevent thermal damage.

That is the criticality: one integrated instrument must continuously deliver two opposite thermal realities — hot, inert argon for heating and conditioned cool argon for seal protection — while operating safely, predictably, and repeatably in a test facility.

NEOMETRIX’s Argon Heating & Cooling System is engineered precisely for this role: a closed‑loop, instrumented, interlocked thermal‑conditioning package that heats sodium‑exposed mechanisms while simultaneously safeguarding seals and interfaces through controlled cooling.

1) What the System Is
The Argon Heating & Cooling System is an integrated facility comprising:
● A hot argon circulation loop to maintain argon at ~200 °C and heat IFTM components (hot argon supply for controlled heating).
● A cool argon system to cool seals and sensitive components (cooling targets typically ≤45 °C), including cold argon injection to prevent hot gas ingress into seal regions.
● Buffer tanks (hot and cool) to stabilize pressure and enable reliable operation under low-pressure conditions.
● Argon-to-air coolers and dedicated cooling-air blowers to remove heat reliably from the circulating argon streams.
● A vapour trap in the return line to capture sodium vapour entrained in argon returning from sodium-adjacent regions.
● Instrumentation, control logic, permissives, alarms, and interlocks for automated, test-ready operation (including MCC/control panel integration).

2) Why It’s Critical (Engineering Purpose)
A) Preventing sodium solidification and motion loss
The heating loop ensures critical mechanical interfaces remain free of solid sodium deposits. Maintaining temperature prevents sodium from freezing on rails and enables free movement of the pot/rails interface.

B) Protecting seals that must not see high temperature
Inflatable seals and sprocket-shaft sealing regions require cooling because they cannot tolerate high temperature. Cold argon injection is used to prevent hot argon from reaching seal locations, protecting sealing performance and reducing costly, complex seal replacement.

C) Maintaining stable operation under controlled low pressure
The system is intended to operate under controlled low gauge pressures; therefore stable pressure control, buffering, and leak-tight operation are essential for repeatable thermal performance.

D) Keeping contamination risk under control
A sodium vapour trap is provided in the return path to prevent sodium vapour carryover into recirculating equipment, reducing contamination risk and protecting downstream components.

3) System Architecture Overview (How It Works)
3.1 Hot Argon Heating Loop — Functional Description
Core concept: Argon is circulated in a closed loop, heated in a forced-through electric heater vessel, delivered to the mechanism, then cooled back down before recirculation.

1. Buffering & pressure stability: The hot buffer tank provides gas inventory and pressure stability; make-up argon is introduced as required to maintain set pressure.
2. Recirculation blower drives flow: A dedicated hot argon blower provides continuous circulation through heater, supply header, and return path.
3. Dedicated cold injection tap-off (seal protection): A small conditioned flow is tapped to the annulus between the leak tight cell and support table to prevent hot argon ingress to seal regions.
4. Electric heater vessel raises argon to ~200 °C: Multi-bank electric heating provides controlled ramp-up and stable hot argon delivery.
5. Heat delivery to IFTM parts + sprocket-region heating: Hot argon supplies controlled heating to IFTM parts; a trickle flow may be provided for local regions such as sprocket areas.
6. Return → Vapour Trap → Cooler → back to ~45 °C: Return argon passes through the vapour trap, then an argon-to-air cooler to reduce temperature before recirculation.

3.2 Argon Cooling Loop — Functional Description
Core concept: A dedicated cool‑argon loop provides stable low‑temperature argon for seals and other sensitive interfaces.
● Redundant cool-argon recirculation blowers (working + standby) for high availability of seal protection.
● Cool buffer tank for pressure stability and gas inventory.
● Argon-to-air cooler and dedicated cooling-air blower to remove heat and maintain required low temperatures.
● Cold argon injection arrangement to block hot gas migration into inflatable seal locations.

4) Instrumentation, Control Philosophy, and Interlocks
4.1 Temperature measurement & closed-loop control
● Temperature indication and alarms at heater inlet/outlet and cooler inlet/outlet locations.
● Temperature monitoring at critical process points (e.g., RSL outlet, seal inlet/outlet) with defined alarm limits.
● Heater power modulation to maintain outlet temperature; protective trips on high temperature conditions.

4.2 Pressure measurement & pressure control
● Pressure transmitters/indicators on buffer tanks with staged high/low alarms.
● Automatic make-up/vent control via control valves to maintain set pressure.

4.3 Flow measurement & protection interlocks
● Flow measurement on critical lines (e.g., heater flow) with low-flow alarms.
● Heater trip on low argon flow to protect heater elements and ensure safe operation.

4.4 Blower health monitoring and permissives
● Differential pressure indication across argon and cooling-air blowers to confirm proper functioning.
● Permissives ensuring argon circulation is allowed only when cooling-air blowers are operating.

4.5 System-level interlocks (typical)
● Argon recirculation blower start permitted only if cooling-air blower is running (ensures heat rejection capacity).
● Heater trips on low flow, high outlet temperature, and/or blower trip conditions.
● Automatic standby start of cooling-air blower on working blower trip (where configured).

5) Major Components (Packaged Engineered System)
5.1 Heating System Components
● Hot argon recirculation blower
● Hot argon heater vessel (~12.5 kW, multi-bank arrangement)
● Hot argon buffer tank (~3 m³)
● Hot argon-to-air cooler (~8 kW) with cooling-air blower
● Sodium vapour trap

5.2 Cooling System Components
● Cool argon recirculation blowers (2× for redundancy)
● Cool argon buffer tank (~2 m³)
● Cool argon-to-air cooler (~1 kW) with cooling-air blower
● Cold argon injection distribution to seal-sensitive regions

5.3 Common Components and Typical Construction
● Carbon steel argon piping (commonly 4-inch), suitable for insulated hot lines and controlled routing/expansion.
● Isolation valves (manual and pneumatically actuated) and dampers for controlled distribution and isolation.
● Instrumentation fittings, manifolds, pressure relief and safety accessories as per design.

6) What Makes the System Fully Fledged (Beyond Hardware)
● End-to-end scope: design & engineering, procurement, manufacturing, inspection, testing, installation, commissioning, and guarantee support.
● Test-grade safety logic: interlocks and trips designed to prevent unsafe thermal states and protect expensive components.
● Operational visibility: comprehensive instrumentation for temperature, pressure, flow, and blower health to support repeatable, auditable test runs.

7) Typical Operating Sequence 
1.  Start cooling-air blowers and verify permissives for safe heat rejection.
2.  Stabilize system pressure using buffer tank control and make-up/vent valves.
3.  Start argon recirculation blower(s) and confirm stable circulation and DP indications.
4. Ramp heater output under closed-loop temperature control to deliver hot argon (~200 °C).
5. Maintain seal protection using cool argon loop and/or cold argon injection to prevent hot gas migration into seal regions.
6. Operate continuously with alarms, trips, and automatic standby switching (where configured) to ensure uptime and equipment protection.

8) Technical Specifications

  

    
Parameter
    
Typical Value / Description
  
  

    
Hot argon setpoint
    
~200 °C (controlled heater outlet temperature)
  
  

    
Cooling target (seal protection)
    
Typically ≤45 °C (with seal limits often specified ≤65 °C)
  
  

    
Operating pressure
    
Controlled low gauge pressure (e.g., order of mbar(g) depending on facility)
  
  

    
Hot buffer tank volume
    
~3 m³
  
  

    
Cool buffer tank volume
    
~2 m³
  
  

    
Heater vessel power
    
~12.5 kW (multi-bank arrangement)
  
  

    
Hot argon-to-air cooler duty
    
~8 kW
  
  

    
Cool argon-to-air cooler duty
    
~1 kW
  
  

    
Cooling-air blower (hot cooler)
    
~2650 m³/hr @ ~300 Pa (typical)
  
  

    
Cool argon recirculation blowers
    
~65 m³/hr @ ~5500 Pa (2× for redundancy)