Regular and continuous blowdown of boilers
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Some boilers can be equipped with only a continuous exhaust system rather than a separate exhaust system – which standard or regulation specifies this clearly? Is it clearly specified that the installation of continuous blowdown and periodic blowdown is determined based on the boiler’s capacity or pressure rating?
Article 160 stipulates that units equipped with superheaters are generally required to have a continuous exhaust system
The locations of continuous and fixed discharge are different; both should be provided.
I have never seen any standard or regulation that explicitly allows for the omission of rows and the use of only consecutive rows. Both in-line and fixed arrangements are available; the size of the in-line arrangement is simply adjusted appropriately depending on the water quality conditions under which the boiler operates.
Continuous sludge discharge is also known as surface sludge discharge; this method involves continuously removing the water with the highest concentration from the surface layer of the boiler water. Its function is to reduce the salt content and alkalinity in the boiler water, preventing excessive concentration of the water from affecting the quality of the steam. Periodic slag discharge, also known as intermittent slag discharge or bottom slag discharge, serves to remove the water sludge that accumulates at the bottom of the boiler, as well as the ferruginous deposits formed after phosphate treatment. Periodic sewage discharge lasts for a short time, but it has an extremely strong ability to remove sediments from the boiler. Since fixed-row and continuous-row systems serve different purposes, they cannot replace each other; both are necessary to ensure the quality of water in the boiler. This post was last edited by realman on 2009-3-17 17:26.]
Thank you all, but indeed there are many boilers that don’t have exhaust settings. Was it replaced with a waste heat cooling tank?
Continuous discharge, also known as surface discharge, involves the continuous removal of boiler water from near the water surface. The purpose of this wastewater discharge is to prevent adverse effects caused by excessive salt and silicon levels in the boiler water. It also removes fine particles and suspended slag from the boiler water. The displacement size should be adjusted according to the salt content. Periodic drainage is also known as intermittent drainage or bottom drainage; it involves regularly discharging a portion of the boiler water from the lowest point in the boiler’s circulation system. The main purpose is to remove water sludge and other sediments. Due to gravity, these water sludge usually settle at the bottom of the water cycle.
Rowed and fixed arrangements are two different concepts
Continuous discharge, also known as surface discharge, is used to control the salt content in boiler water； Regular sludge discharge is the removal of deposits from the bottom of the boiler
The boiler’s waste water enters the continuous discharge expansion tank before proceeding to the regular discharge. Depending on the size of the boiler system, continuous drainage and periodic drainage are generally required.
Both continuous and scheduled sewage discharge should be implemented; the frequency of discharge depends on water quality – it needs to be done more frequently when the water quality is poor.
Continuous discharge is not suitable for boilers of small capacity, as they have a large water discharge volume and consume a lot of heat. Generally speaking, it seems that boilers under 6 tons rarely use continuous blowdown; moreover, vertical small boilers used in industrial applications typically employ periodic blowdown. Only for small industrial furnaces.