PRJ-00069 - Vitiated Cone

[CSaungsomboon-FTT]

Issue to document design and manufacture of the Vitiated Cone product.

Further information can be found here: C:\FTTVault\Projects\PRJ-00069 - Vitiated Cone P:\Instruments\Photographs\Photographs - Enclosed MLC\Construction

[CSaungsomboon-FTT]

Information

The Vitiated Cone is an apparatus which burns samples in a reduced oxygen atmosphere to measure the following parameters:

• Heat release rate
• Smoke/gas production rate
• Mass loss rate
• Ignition time
• Ignition behaviour

The cone is the instrument described in ISO 5660-1, and is taken from the FTT Standard Cone.

This is achieved in this instrument by controlling the total volume of atmosphere fed into the chamber.

The instrument requires the following components:

• Exhaust hood and duct system
• White light smoke density system
• 5660-1 Cone with water collar to prevent top plate warping
• Test Enclosure:
  • 370 x 300 x 320 mm +/-20mm
  • Door
  • Window - in door or walls
  • Gas port at sample level
  • Radiation shield/Ignition circuit/specimen holder (FTT standard Cone)
  • Two entry points for air/gas supply for enclosure atmosphere - fitted with baffles
  • Chimney: 600 x ⌀155mm +/-2mm @ 1mm thick SS.
• Weighing load cell with water cooling
• Air/Gas supply system
  • Shut off valves for each gas component
  • Flow regulators for each gas component
  • Flow meters to measure gas component flow rate
  • Flow stabilising devices
  • Gas mixing chamber
  • Flow meter for total flow rate to enclosure
• Oxygen analyser to measure the enclosure atmosphere
  • Will be measured at the sample height port @ 20mm +5mm distance
• Data collection system (Rack)

The system will be calibrated without gas supply to the enclosure, and with the door open.

Test Procedure

1. Equipment is calibrated and left ready to be switched on
2. 60s of surrounding baseline data is collected @ 5s intervals (shortened if short burning sample)
3. Door closed, gas supply turned on and set to desired point. Enclosure allowed to purge and stabilise for 90s.
4. 60s of initial baseline data collected @ 5s intervals.
5. Add specimen and allow system to settle for between 60 and 120s. This time should be kept constant between samples.
6. Remove radiation shield and start test. Mark flashing/flaming occurrences and sample physical changes. The min test duration is 5mins.
7. Collect all data until:
   • 32 min after the time to sustained flaming. Data is processed to time to sustained flaming plus 30 min.
   • 30 min have elapsed and the specimen has not ignited (only for 20.95 % O2 tests)
   • O2 reading returns to a value greater than the initial baseline value - 100 ppm of O2 concentration for 10 min. The end of test is the beginning of the 10 min period.
   • The mass loss of the specimen is less than 0,1 g for 60 s. The end of test is the beginning of the 60 s period.
8. Remove sample and turn gas supply off. Stop data collection.

[CSaungsomboon-FTT]

Standard: ISO 5660-5-2020

[CSaungsomboon-FTT]

Meeting 02/01/24 - JM, CS

1. Idea was raised for replacing the rack with a control box based in a schroff bin - two designs consisting of 1 standalone system, and 1 system to be used interchangeably with a cone.

2. Current rack design with a cone means that the touchscreen is impractical to use - if the touchscreen was only used once, then practicality improves, but not by much.

   • Q: How many O2 concentrations are required for an average test procedure for a customer?
   • Cone design would also require a method of moving the vitiated cone in and out of position - this could involve rails or an equivalent method

3. Idea was raised for placing the gas system on a baseplate that will mount within a rack and a control box - this futureproofs the system.

4. Jim will look at the following:

   • Add gas pipework and change to compression fittings
   • Add O2 measurement at sample height and also add thermocouples
   • Look at pump alternatives for a smaller pump
   • Find appropriate models for the 3-way valve, side panels and door

5. CS To do:

   • [x] Add side panels and rear door to Rack
   • [x] Add in/out ports to side panel
     • Power
     • N2
     • N2 Zero
     • Air
   • [x] Add clip system to route wires/pipes up to the hood
   • [x] Add all components to the gas system and route appropriately

[CSaungsomboon-FTT]

[CSaungsomboon-FTT]

Gas System

[CSaungsomboon-FTT]

[CSaungsomboon-FTT]

Will update plumbing:

• smooth flow of the input gases using the 3 way component
• add splitter off of the nitrogen line for the nitrogen zero line - this will travel to the front plate

Option for splitter - will try another variant with a T

[CSaungsomboon-FTT]

Plate area was 600x600mm which is the size of the rack top and not its internal base size of 450x450 - I have replumbed the plate as below

there is a T that feeds into the total mass flow with a very short line which I think will be okay - I am unsure how affected the MFCs are by turbulence, and there is not a lot of pipe where the O2 and N2 to mix.