Dear experts, what is the lowest temperature to which condensate can be flashed during flashing?
Thread Content
Dear experts, I would like to ask: when condensate water is flashed, is the lowest possible pressure at which it can be flashed 0.1–0.15 Mpa at 105°C? When using closed-loop condensate recovery, can the condensate be flashed to 85°C?
So if I want to use a shell-and-tube heat exchanger (with circulating cooling water at 30-40°C) to cool the flash vapor, can it still flash to 85°C?
Since circulating water cooling is used, it is more accurate to state it as “cooled to xx °C” rather than “vaporized to xx °C”. In addition, it is necessary to consider the issues of vacuum breakdown and pressure balance in the condensate system, to prevent pressure fluctuations from causing the condensate transfer pumps to fail to operate properly.
It’s not the condensed water that cools the circulating water; rather, after entering the flash tank, the condensed water exchanges heat with the steam that is generated through flashing, and then returns to the tank due to gravity. I would like to know what the lowest temperature at which flashing can occur using this approach is.
Following this approach, as mentioned in Building 3#, it is necessary to install a vacuum pumping system at the gas outlet of the flash vapor condenser, in order to evacuate the system to a vacuum level below the saturated vapor pressure of water at 85°C (58 kPaA). It is far less simple and practical than using a circulating water cooler to circulate and cool the condensate.
Theoretically, it is possible; by ensuring good system airtightness, the saturated vapor pressure of hot water at 85°C is 57.8 Kpa – as long as the pressure in the flash tank reaches this value
Bro, it can be flashed to 85 degrees Celsius. Will you be using steam at a pressure lower than one atmosphere later on? If you want to use it, you need to attach a vacuum ejector pump or another type of vacuum pump to it.