News & Publications
Centers of Excellence

Large Hot-Gas Filter Vessel

Large Hot-Gas Filter Vessel
A larger hot-gas filter vessel (HGFV) handles gas flow from the transport reactor development unit at its expected operating conditions.

Operating Conditions

  • Inlet gas temperature: 1000°–1800°F (590°–980°C)
  • Operating pressure: 120–150 psig
  • Volumetric gas flow: 325 scfm
  • Number of candles: 19 (1 or 1.5 m)
  • Candle spacing: 4.25 in.
  • Filter face velocity: 2.5–10 ft/min
  • Particulate loading: <10,000 ppm
  • Temperature drop across HGFV: <50°F (30°C)
  • Nitrogen backpulse system: unheated


  • The vessel is 48 in. in diameter and 85 in. long.
  • The refractory lining decreases the diameter to 28 in., with a 24-in.-diameter shroud to distribute the airflow.
  • The vessel is sized to handle candle filters up to 1.5 meters long.
  • Candle filters are 2.375 in. outside diameter, with a minimum 4-in. center line-to-center line spacing.


Filter vessel ports enable temperature and pressure measurements and insertion of a water-cooled borescope probe for inspecting candle filters online. The ash letdown system consists of two sets of alternating high-temperature valves, with a cylindrical pressure vessel to act as a lock hopper. Additionally, a preheat natural gas burner is used to prevent condensation in the vessel during gasifier start-up.

The nitrogen backpulse system will backpulse up to four sets of four or five candle filters in a time-controlled sequence. The pulse length and volume of nitrogen displaced into the filter vessel are controlled by the regulated pressure (up to 900 psig) of the nitrogen reservoir and the solenoid valves used to control the timing of the gas pulse.

Useful Links

Transport Reactor Development Unit