Pollutants such as NOx and SO2 are controlled with CFB unit via low temperature combustion and limestone injection for S02 removal.

Pollutants carried from CFB are captured by recycle cyclones (for solid recirculation) solid dropout section beneath  Ljunstrom Air preheater and ESP.

Electrostatic Precipitator used to meet the particulate emission requirement __ mg/Nm3 at 6% 02 vd.

ESP has one inlet duct which the gases pass uniformly  at a velocity of ? m/s

As voltage is raised electrical breakdown of gas  which close to electrode surface takes place, this breakdown produces large number of gas ions called?

over __ % high collecting efficiency will be reached base on above operation condition.

Input dust loading = 23.8 g/Nm3 ,  Outlet dust concentration <  mg/Nm3?

A smaller portion of ash is expected to be so fine that it remains in __ flow streams in flue gas  to travel out through the back pass with flue gas.

Ash is removed from system in 3 places : 1. ? 2.  ljunstrom Air apreheater gas outlet hopper and 3.ESP hopper.

Ash entrained within the flue gas passing through the backpass is considered to be?

The __ mm inlet slide gate valve is located in plenum exit above the water cooled screw conveyors. (BA combustor bed drain valve)

screw is to cool the ash coming from the boiler. Water recirculation must be always on , when bottom ash is removed.

Water recirculation must be  closed (manually) within approximately __ mins after screw conveyor stop to avoid  condensation inside the screw, can reduce to 5 mins in situation when  conveyor is empty.

Furnaces wall is composed of  __mm OD tube on 88.9mm center.

Backpass sidewall tubes are composed of  __mm OD fin welded tubes on 114.3mm centers.

Backpass front, rear , roof walls are composed of  __mm OD fin welded tubes on  114.3 mm centers.

__ fiber block insulation is composed of rock and slog fibers, inorganic binder and a small amount of organic binder.

On initial start up of unit, mineral fiber products maybe heated rather quickly to C?

From 177C to the unit operating temperature should not increase more than __C per hour ?

at __C the insulation will smoke. Smoke  should be subside after the unit has been at operating  temperature for approximately 4 hours.

Hot air or gas over __C , should not be allowed to enter duct suddenly during the initial set up.

Setting  Material - The incremental temperature increas less than __C/hr is required only the first time a unit is brought up to opersting temperature.

The deposition of an insulating film on the water side of tube wall, raises the hot face temperature and may result in overheating of tube section.

Used as mean controlling boiler water concentrations (solid and alkalinity) and remove sludge formations.

Furnace tubes should be examined externally for ____, burning , corrosion, erosion and cracking.

Tube repairs - Tube section is removed by cutting across the tube, sufficiently __ and __ the failure.

The ___ cuts  must extend beyond the perpendicular cuts sufficiently to permit welding completely.

Tube repair - with an angle of approximately  __ is necessary to prevent wearing on welded zone due to high particle loads.

uncombined silicon oxide?

Harmful effects of dust - particulates less than __ microns in size are potentially the most harmful.

Disabling lung disease cause by inhilation of silica dust, generally produce 5-20 years.

Evidence suggest that particles below __  micron in size maybe the most dangerous.

Rapidly developing silicosis, symptoms appear in 8- __ months after first exposure.

TVL meaning?

ACGIH meaning?

TLV of mineral dust are time weighted, permissible exposure of __ hours per day, 5 days per week.

Give some examination to perform in which the airborne concentrstion of dust may exceed? Give only one.

Primary means of controlling airborne dust is through use of proper?

Coal feeder system consist of 3 parallel trains, each capable of maximum feed rate of __ kg/hr

Fuel gravimetric feeders are also pressurized with cold primary air via __ inches diameter of piping connection.

Combustion Air at MCR - Primary air fan (flow inlet vane controlled by combustion air flow control) ? %

Combustion Air at MCR - Secondary Air Fan (flow inlet vane controlled by combustion air flow control) ? %

FAB - air to siphon seal, constant Flow ? %

Limestone feed system - constant flow (approximately )%?

__ flyash at Ljungstrom air pre heater and flue gas cleaning equipment hopper outlet ( ash collection and conveying system)

__ bottom ash from furnace grate via ash cooler outlet.

During normal operations, ash temperature will range up to 900C , are provided on furnace windbox - intended use only when unit essentially cooled down.

Each start up burner has firing capacity of __ kcal /hr?