Boilers Test Questions With Correct Answers

Boilers Test Questions With Correct Answers Cast iron boilers - ANSWER- low pressure, corrosion resistant, able to be taken in on carts, easy to assemble, does not require special foundation, come in vertical or horizontal sections. ***sections are held together w/ push nipples stay bolts, can be expanded Firetube boilers - ANSWER- water outside, fire in tubes, Heat combustion in tubes, not actual fire in tubes. -vertical tubes -Passes through 3-4 times. Gases -high or low pressure. Large amount of water HRT boilers - ANSWER- Fire tube, has a drum supported by lugs and slings -only 2 pass construction. Simplest form. Old design and still manufactured -external furnace or firebox. -external def. not as efficient -internal def. greatest amount of heating surface -baffle for HRT is called bridge wall. Located in the path of combustion gases. Increases efficiency. - can burn any fuel Scotch marine fire tube - ANSWER- most common and most efficient. -completely internal furnace. -main furnace is corrugated. Makes it stronger and causes turbulence, scrubbing action and absorbs more heat. Increases surface area. Types of Scotch marine - ANSWER- Dryback and wetback. Dryback easily cleaned and less efficient. Less costly. Wetback more efficient, more costly. Harder to clean baffles - ANSWER- on all boilers. directs flow for greatest efficiency. Pushes it to where it wants to go. Watertube boilers - ANSWER- -steam and water drum -combustion gases outside tubes. -less water than fire tube. -faster reaction time and recovers faster. Comes back to set point quicker. -found in power plants. -Types of construction- straight tube, bent tube, flex tube, membrane 2 or more drums. Steam drum top, mud drum bottom. -Tubes are attached using an expanded joint. Boiler stays - ANSWER- horizontal, vertical, or diagonal. Prevents bulging where not supported by stays. Electric boilers - ANSWER- electrode type or.. -resistance coil type. 10KW= 1 boilers horsepower.