Jan 13 2015 · Natural circulation is the ability of a fluid in a system to circulate continuously with the difference in density being the only driving force. In another way natural circulation is caused by convection currents which result from the uneven heating of the water in a boiler. It may be either free or accelerated and is primarily used in boilers and evaporators.
The waste-heat steam generation plant 7 is designed as a vertical boiler and in the present case works according to a dual-pressure steam process. A horizontal boiler could of course also be used. The low-pressure system is designed as a circulation system with drum a forced-circulation
The gas inlet nozzles are provided with a forced circulation. Boiler water is taken from the lower boiler area and supplied to the double tubes in the gas inlet zone by recirculating pumps. The maximum metal temperatures occur at the inlet of the cone and the transition from the cone to the cylindrical tube.
Feb 27 2020 · Each ANDRITZ MAERZ ® double-chamber furnace consists of a high-temperature furnace (650 to 1220°C) with recuperative burners and a low-temperature furnace (200 to 830°C) with forced circulation. Both furnace types meet the qualifications for AMS 2750 E classification 2 which requires very high precision in the thermal process (+/- 6°C).
This forced circulation re-boiler is for more than 20 years in operation. One annual inspection replaces cleaning every 4 to 5 days. A significant cost saving results from the higher recovery of acetic acid and the more concentrated residue in the bottoms.