Issues regarding closed-loop condensate recovery systems
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I encounter this problem when designing systems. If an open system is used, it’s easy to control, but the last tank ends up requiring one or two hundred tons of circulating water to condense the steam. If a closed system is used, we’ve consulted manufacturers before; in such cases, an ejector is installed at the outlet of the condensate pump, and the flow rate of the condensate is used to draw the steam from within the tank and carry it away together. However, it seems difficult to control the pressure inside that tank. I’m curious to know whether the condensate systems in your factories are open or closed, and what the performance is like. Thank you @ylb913
I really have no say in this. I’ve seen this used in other factories with high-pressure steam, in many sets that switch back and forth. The steam from our wastewater vapor system, as well as the steam condensate from an amine regeneration unit, is sent under its own pressure to a constant-pressure tank in the power plant without being cooled; thereafter, it is pumped out for heat exchange and cooling. The heat tracing for another set of amine solution regeneration and sulfur units has always been cooled by circulating water before being sent to the same tank in the power plant. Because there were concerns that the condensed water wouldn’t be able to flow out under its own pressure due to the additional setup added later, a condensed water tank was installed. It operates at atmospheric pressure; the vapor at the top causes the circulating water to condense, and the water at the bottom is pumped out. However, this tank has never been put into use – the condensed water still flows under its own pressure to the areas where it needs to be condensed.
Right now, the main concern is figuring out what to do in case there’s no place to use this atmospheric pressure steam. So, have you seen more open-type systems?
Closed condensate system: 1. First of all, it is a system; therefore, the steam traps installed in it must be of good quality, as excessive steam leakage can affect the pressure of the condensate system. 2. A circulating water cooler should be installed on the closed condensate recovery tank to control the pressure. 3. The ejector is only used to remove non-condensable gases in order to prevent the condensate transfer pump from running dry; it is not feasible to use it to push large amounts of steam.
1. Understand. 2. If circulating water cooling is used, does that mean the tank is designed to operate at atmospheric pressure? Still under pressure? 3. It’s not practical to remove non-condensable gas; it seems that one can only consider opening the vent valve to release gas if there is instability in pressure over time. It still seems more appropriate to remove steam. .
Our facility uses a closed-loop recycling system: material enters a recycling tank where vapor is generated at a pressure of around 1 Mpa; the condensate at the bottom is recovered using multi-stage pumps. The results are quite satisfactory
That’s a good idea; then the pressure of the condensate pump will need to be increased significantly
We used a closed system, but it was completely abandoned after just over a year, as it was deemed not worth the cost and failed to serve the purpose of saving steam.
What was the original setting like? Where does the vapor that comes out of flashing go? Is the reason for abandonment that it’s difficult to control, or is there some other reason? Thank you
We really don’t understand anything about machinery; the manager avoids talking about it for fear of being criticized by the employees.