Question

Which of the following options is used for mixing air with fuel supply?
1. Booster fan
2. Blowdown
3. Chimney
4. Fusible plug

Answer 1

Correct Answer - Option 1 : Booster fan

Explanation:

Booster fan:

• The main objective of any booster fan is to increase flue gas pressure to promote its flow through the ducts and to the top of the chimney.
• Due to the compression effect and fan inefficiency, a booster fan will slightly warm the flue gas as it passes through the fan before entering the stack.
• A booster fan is used for mixing air with fuel supply.

Blowdown:

• Blowdown occurs when water is removed from a steam boiler while the boiler is operating.
• Boilers are “blown down” to remove suspended solids and bottom sludge from steam boilers.
• Removal of suspended solids helps insure the boiler generates high-quality steam.
• It also prevents foaming at the water surface which can lead to unstable water levels and excessive carryover of liquid in the steam.

Chimney:

• A chimney is an architectural ventilation structure made of masonry, clay, or metal that isolates hot toxic exhaust gases or smoke produced by a boiler, stove, furnace, incinerator, or fireplace from human living areas.
• A chimney is a structure for venting hot flue gases or smoke from a boiler, stove, furnace, or fireplace to the outside atmosphere.
• The working of the chimney is based on the natural draft or stack effect. The hot air being lighter rises to the top.
• The taller the chimney, the more draught or draft is created.

Fusible plug:

• it is a very important safety device of a steam boiler that protects the fire tube boiler against overheating.
• Its object is to put off the fire in the furnace of the boiler when the level of steam in the boiler falls to an unsafe limit, and thus avoid the explosion which may take place due to overheating of the furnace plate.