IMI Remosa designs and manufactures Variable Orifice Valves (VO) since 2001. Remosa's VOs are successfully installed all over the world.
The purpose of the Variable Orifice is to drop the pressure of the flue gas coming from the catalyst regeneration process.
The number of the VOs in series depends on the amount of the pressure is required to drop before the CO Boiler.
The Variable Orifices are installed after the Flue Gas Slide Valve in vertical position as well as in horizontal position, according to the plant pipe lay out.
Each VO drops the flue gas pressure through the fixed multiple orifices as well as the through a butterfly disc.
The multiple orifices are through holes performed in the VO's orifice plate arranged perpendicularly to the gas stream. In the same orifice plate is arranged, in central position, the butterfly disc.
While the fixed orifices dimension and number are evaluated in order to induce a fixed minimum amount of pressure drop through the equipment, the rotation of the butterfly disc adjust smoothly the variable required pressure drop.
The VO's shell can be cold wall as well as hot wall according to the pipe design where it is installed. The main plate where the multiple fixed hole are performed and where the butterfly disc is arranged is protected by an abrasion resistant lining.
Due to the high operating temperature, the required mechanical strength of the butterfly shaft is Inconel X-750.