Slide Valves
Slide valves are named according to their position in the plant:
- Spent
- Recirculation
- Regenerated
- Cooled
- Flue Gas Double Disc
Regenerated and spent catalyst slide valves are designed to control the catalyst flow to the reactor. In an emergency these types of valves must be able to stop the catalyst flow.
Cooled catalyst slide valves and recirculated catalyst slide valves allow to control the flow between the upstream and downstream sections of the regenerator.
The flue gas double disc slide valve regulates the flue gas flow to the CO boiler and the operating pressure of the regenerator.
They all have just one disc, except for the Flue Gas type which has two. Single disc valves are used for dense fluids while double disc ones are used for gaseous media.
Slide valves can be designed in cold or hot wall configuration. The body for hot wall valves has an abrasion resistant lining on hex-mesh. Cold wall valves have their carbon steel body lined with refractory material and are capable of operating at temperatures up 950 °C.
Regardless of the type of slide valve, the disc is built as a single piece lined on its entire top and front surfaces and for over 50% of its bottom surface with abrasion resistant material. The sides and the bottom part of the disc in contact with the guides are hard-faced with cobalt-base material and then ground.
The orifice plate surfaces facing the disc and those exposed to the flow are also lined with abrasion resistant material cast on hexagonal mesh and then ground.
Remosa has developed a special procedure for anchoring the abrasion resistant lining to the edges by installing corner tabs, separated from the hexagonal mesh by using binding bars.
Stems are made of SA 182 Tp 304H material for cold wall valves and SA 182 F11 material for hot wall spent catalyst slide valves.
