With today's energy prices, a plant's steam/condensate systems cannot afford to vent flash steam to the atmosphere. The non-modulating steam system's operational design allows the condensate and flash steam to be recovered in a flash tank system. This flash steam recovery system differs from a modulating steam system.Condensate/flash steam (two-phase flow) discharging from a non-modulating steam system process can be recovered in a flash steam system or high-pressure condensate return system. Non-modulating steam condition means no control valve modulates steam flow to the process. If a control valve is present, the steam control valve always maintains a steam pressure to the process above the pressure in the condensate recovery system.

A non-modulating process steam system provides a constant steam pressure to the process, thus providing a constant pressure differential across the steam traps or condensate discharge control valve. See Figure 1.

The two-phase flow (flash/condensate) from the process discharge can be directed to the pressurized flash tank for separation. The purpose of the flash/condensate separation process is to separate the flash steam and condensate, leaving no entrainment of condensate into the flash steam. The flash steam can then be delivered to a lower pressure steam line. This method is referred to as a cascading flash steam system. In a high pressure condensate return system, the high pressure in the condensate return line greatly reduces the percentage of flash steam, and typically the flash steam is used for the deaerator steam consumption.

MORE NEWS