Sage-Tips

What is boiler continuous blowdown?

What Does Continuous Blowdown Mean? This is a boiler feed water treatment process that aims to remove suspended solid impurities in a boiler to enhance heat transfer efficiency. It is also a control strategy, whereby it limits the amount of corrosion caused by these impurities.

What is continuous blowdown and intermittent blowdown?

Continuous blowdown is taken from the zone of highest solids concentration in the steam drum and is usually capable of keeping solids within the required concentration limits. Intermittent blowdown is taken from the bottom of the steam drum and is used to keep it sludge-free during operation.

What is continuous blowdown valve?

This type of valve is installed close to the water surface in the boiler. Continuous Blow-Down Valves remove dissolved solids at a continuous rate from the top layer of the boiler water, insuring that the minimum required quantity is discharged from the boiler during the process.

What are the types of blowdown?

There are two main types of boiler blow down, surface blow down and bottom blowdown.

• Bottom Blowdown: As its name suggests, this function happens at the bottom of the boiler commonly known as the mud drum.
• Surface Blowdown: Happens near the surface at the location where the concentration of dissolved solids is highest.

How does a boiler blowdown work?

Boiler blowdown is water intentionally wasted from a boiler to avoid concentration of impurities during continuing evaporation of steam. The water is blown out of the boiler with some force by steam pressure within the boiler.

How do I reduce the blowdown on my boiler?

There are three ways to minimize boiler blowdown that will save water for your boiler plant. Automate Surface Blowdown • Proper Pre-treatment • Condensate Recovery Automating Surface Blowdown Automating the surface blowdown allows for the highest TDS (total dissolved solids) portion of the boiler water to be purged.

What is boiler blowdown rate?

Rate of blowdown is a rate normally expressed as a percentage of the water feed. In the case of boilers, rate of blowdown is the removal rate of water from a boiler. Its purpose is to control boiler water parameters within prescribed limits to minimize: Scale. Corrosion.

How often blowdown steam boiler?

How often should a boiler have a bottom blowdown? The most common recommendation for the frequency of bottom blowdown of a steam boiler is at least once every 8 hour shift.

How do you measure a boiler blowdown?

The optimum blowdown rate is determined by various factors including the boiler type, operating pressure, water treatment, and quality of makeup water. Blowdown rates typically range from 4\% to 8\% of boiler feedwater flow rate, but can be as high as 10\% when makeup water has a high solids content.

What is a continuous blowdown on a steam boiler?

A continuous blowdown is an optional feature and may not be included on your steam boiler; however, all steam boilers should include a means for manual blowdown as standard equipment. Manual blowdowns are accomplished through tapings at the bottom of the boiler.

What are the benefits of a boiler water blowdown reduction?

A reduction in boiler water blowdown can result in significant fuel and water savings. In some installations, boiler water solids are lower than the maximum level permissible.

How much blowdown do you save with a continuous blowdown system?

In general, the average plant saves approximately 20\% of boiler blowdown when changing from manually adjusted continuous blowdown to automatically controlled continuous blowdown. This reduction is gained without risk of scale or carryover due to high boiler water solids.

What is a continuous Surface blowdown line?

– Continuous surface blowdown is often a 1” port/blowdown line coming off the boiler at the normal water level.