61-79 Flashcards
- How is the density of smoke measured? How do you use a Ringleman Chart? BOW 2-3-4
With an Opacimeter or Ringleman chart.
To use the Ringleman chart, hold at arms length looking through the hole in the chart. Compare the shade or density of the smoke seen through the hole to the corresponding shade on the chart. Observers line of sight should be at right angle to the direction of the smoke travel. Observer should not be less than 100 feet or more ¼ mile from the stack. Observer should not look towards bright sunlight. The background immediately behind the stack should be free of buildings or other dark objects
- What grades of smoke are allowed in boiler operation? City Code
No darker than Grade 1 for more than 5 minutes per hour and no more than 3 times in a 24 hour period.
- What are seven heat losses in a boiler? SPO 6-7-8 BOW 3-4
- Moisture in the air
- Moisture in the fuel
- Moisture formed in the burning of hydrogen
- Incomplete combustion
- Unburned carbon in the ash
- Heat carried away in dry flue gases
- Radiation and Blowdowns
- What is the heat content of one pound of good coal and of one pound of carbon? SPO 6-7-8
Coal is 13,000 to 14,000 BTUs
Carbon is 14,450 BTUs
- What is an Orsat Apparatus? Where is it used? Why is it used? SPO 6-7-8 BOW 2-3-4
A flue gas analyzer detecting the amounts of, CO, CO2 and O2 in flue gases.
Combustion gases are sampled from the last pass or the breeching.
It is used to determine combustion efficiency and excess air
- What is a Fyrite analyzer? Where is it used? Why is it used? BOW 3
It is a flue gas analyzer to determine the amount of CO2 and O2 in flue gases.
Combustion gases are sampled from the last pass or the breeching.
It is used to determine combustion efficiency.
- What is a pyrometer? Where would it be located on a boiler? SPO 8 BOW 2-3-4
It is a thermometer for measuring the temperature above the range of mercury.
It would be located in the hot gas passages and in the refractory.
- What are tuyeres (tweeyars)? SPO 6-7-8 BOW 2-3-4
Air admitting grates on stokers.
- What is a water back? SPO 6-7-8
The water back is a water wall that is behind the grate on a stoker and its purpose is to cool the wall to prevent clinkers from sticking to the back wall.
- Define purging and name two types. SPO 6-7-8 LPB 2-3
PURGING is the forced removal of combustibles from the firebox.
PRE-PURGE is before the pilot is lit.
POST-PURGE is after the combustion cycle.
- What precautions are needed before a gas, oil or pulverized coal fire is lit? SPO 6-7-8 LPB 3 BOW 2-3-4
Purge all the combustible before you light the pilot.
The Pilot must be on before the fuel starts.
- What are pulsations? How would you correct this condition? SPO 6-7-8 BOW 2-3-4
Pulsations are when the flame leaves the burner tip and returns.
This may become so severe that the combustion consists of a series of small explosions.
In a Pulverized Coal or Oil furnace, it can be corrected with the proper air-fuel mixture.
In a Gas furnace it can be corrected by increasing the draft.
- How do you pipe an oil supply from the tank to the burner? SPO 6-7-8 LPB 2-3 BOW 4
Oil flows from, the storage tank through the suction strainer, steam or electric driven pump, relief valve, steam or electric heater, discharge strainer. Low oil pressure switch, firing rate control valve, low oil pressure switch then on to the burner or tank return.
Manual isolation valves and bypasses must be installed for all devices so the boiler stays online even during repairs.
- What are some of the difficulties you may encounter when operating an oil fired plant? If you are firing #4 oil and lose oil pressure, what are the first two things you would look for? When would you change a strainer? SPO 6-7-8
Difficulties may include, plugged strainer, improper venting of the tank, failure of the pumps, sludge, air in the suction line, vapor in the pump, oil too heavy to flow, low oil temperature, faulty atomization, carbon formation on burner tip, worn burner tip or low oil pressure.
The first two things to look for are plugged strainers or pump failure.
You would valve over to a clean strainer if then Delta-P was excessive.
- Name three types of nozzles used in oil burners. Explain where secondary air is admitted. SPO 678 LPB 2-3 BOW2-3-4
Rotary Atomizing, Steam Atomizing, Air Atomizing, Pressure Atomizing
Secondary Air is admitted around the tip.
