Boiler blowdown issues
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I recently saw two designs, each different; in both cases, a series of drum units are used to carry out flashing to generate steam and to remove waste fluids. One of them directed the intermittent wastewater discharge there as well, while the other sent it into the gutter. Why is this the case? Can the boiler waste water be recycled and used in the desalinated water reuse system?
After the steam is recovered by flash evaporation, the water must be discharged into the drain.
In the design, is it appropriate to discharge wastewater directly into the gutter through intermittent discharge?
Both continuous and intermittent wastewater discharge can be combined; after steam is recovered through pressure reduction flashing, it is discharged into the sewer system for further wastewater treatment.
Do not combine side-by-side and row-separated discharges. Because the spacing can affect the water quality in the deaeration tank, and it can also cause the safety valve to activate frequently. The most reasonable approach would be to connect them in series to a drain expansion vessel; after expansion, the steam is returned to the deaeration tank while the water is discharged into the drain. It is directly discharged into the gutter at intervals. Since design institutes generally do not have a sewage discharge buffering system for individual chambers, the water discharged from these chambers often causes the temperature in the biological treatment tank to rise above the acceptable level; therefore, it is advisable to install a sewage expansion tank as well as a reservoir.
Why? Why does misalignment cause the safety valve to trip? Which is the safety valve? Why does it cause deterioration in the water quality of the deaerator?
Reply to 5# WakeUp: The quality of the steam generated by flashing will not be worse than that of the desalinated water. If an oxygen remover is used with the flash steam, it should not cause any changes in the water quality in the oxygen remover. Additionally, what you’re experiencing is likely the safety valve of the oxygen remover activating. Firstly, you can adjust the pressure in the oxygen remover using its automatic pressure control system; secondly, you can integrate the flash steam into the steam pipeline network at that same pressure level.
Reply to 7# 654262293: The quality of the steam produced by flash evaporation is better than that of deionized water, but this applies only in the case of continuous discharge； It won’t work if the inter-row and side-by-side arrangements are mixed together, as the wastewater from these arrangements has a higher hardness and conductivity; moreover, increasing the processing volume by mixing them together results in higher steam humidity in the wastewater expansion device, which undermines the quality of the incoming steam. At the same time, in a properly designed system – one that was designed by our institute, Hua Er Yuan – the water channels are usually separated into individual rows or groups. If construction is carried out in such a way that all pipes lead to the same sewage expansion tank, it can cause the safety valves to activate frequently. That’s exactly how our factory operates; recently, people from the Second Institute came and helped us solve many problems. So, our unit is separating the in-line and staggered arrangements. What was discussed earlier were all problems that arose in our company’s actual production.
For indirect pollution discharge, we have added a wastewater cooler.
After cooling, it returns to the circulating water.