Heat recovery from a TMP plant is available at a number of different levels depending upon your mill's process and heat utilization requirements. Primary TMP refiners operating at elevated pressures blow their pulp at these high pressures, generating contaminated steam. This steam can be recovered as clean steam at a slightly reduced pressure using a falling film reboiler.
Because TMP vapors contain NCG, a portion of the vapor must be vented from the reboiler to a secondary condenser. The secondary condenser is used to preheat the boiler feed water going to the shell side of the reboiler. Other refiner processes operating under pressure may also be recovered as clean steam.
Many times the secondary, tertiary and rejects refiners are atmospheric operation and generate contaminated steam containing a substantial amount of air. This heat may be recovered as either hot process water using shell and tube condensers or as hot process condensate using a barometric condenser.