Start burner

The furnace blower or boiler circulator pump starts up to send heated room air or hot water through the ducts or hot water pipes to the steam radiators, or hot water baseboard units, or individual room air registers located throughout the house. When the thermostat is satisfied that the room temperature has reached the set point, the burner shuts off. In furnaces, the blov er continues to run a few seconds until the air temperature drops to about 90° F, then the blower also shuts off. The furnace blower may come on again before the next burner start-up to purge heat out of the furnace, particularly if the fan has a low turn-on set point. The cycle... 

In all experiments a burner power of 16.7 kW and CO2 content of 13.4 0.2 vol.% in the exhaust gas (corresponding to an air ratio of 1.15) were utilized. The burner operated intermittently. Each cycle lasted 20 min and consisted of 15 min burner operation followed by a 5 min pause. According to the safety instructions, air ventilation of approximately 12 s before burner start, as well as 5 s after burner shutdown, was integrated generally. The liquid fuel used was IGO. According to the appropriate German standard, it contained up to 2000 mg of sulphur per kg. 

It is useful to specify at the start the principal quality criteria for each type of product (motor fuels, heating fuels), imposed by the requirements for the different kinds of energy converters motors, turbines, burners. 

When a customer agrees to purchase gas, product quality is specified in terms of the calorific value of the gas, measured by the Wobbe index (calorific value divided by density), the hydrocarbon dew point and the water dew point, and the fraction of other gases such as Nj, COj, HjS. The Wobbe index specification ensures that the gas the customer receives has a predictable calorific value and hence predictable burning characteristics. If the gas becomes lean, less energy is released, and if the gas becomes too rich there is a risk that the gas burners flame out . Water and hydrocarbon dew points (the pressure and temperature at which liquids start to drop out of the gas) are specified to ensure that over the range of temperature and pressure at which the gas is handled by the customer, no liquids will drop out (these could cause possible corrosion and/or hydrate formation). 

A beaker is placed under Y and the combustion may now be started. The Bunsen burner, with the air-hole wide open, and the... 

Is any material added during start-up and shutdown, which can create a hazard on contact with process or plant materials Is the means of lighting flames, e.g. on burners and flares, safe on every occasion ... 

The definition of an automatic burner is A burner where, when starting from the completely shut-down condition, the start-gas flame is established and the main gas safety shut-off valves are activated without manual intervention. This means that a burner is only automatic if it is ignited by means of a remote interlock (e.g. thermostat, timeswitch, etc.) closing. A burner is not automatic if it has a pilot burner that remains ignited in the off condition. Nor is a burner strictly automatic if a start button needs to be pushed, even though the controls may comply with all requirements for automatic burners. 

For start gas supplies two safety shut-off valves are needed on all but the smallest burners. For automatic burners the main gas safety shut-off valve requirements are ... 

Steam is the preferred atomizing medium, since it is more economic than compressed air. Steam consumption is typically less than 0.5 per cent of the fuel burnt on a mass basis, although this rises in direct proportion to turndown ratio. On very large burners, the steam flow is modulated in proportion to fuel burnt. Turndown ratios range from about 5 1 for small shell boilers to 12 1 in watertube applications, making this one of the most versatile burners. The steam condition is important in that it must be dry saturated or slightly superheated at the nozzle to avoid condensate formation. On small or non-continuously running plant where no steam is available for start-up a compressed air supply must be provided until steam becomes available from the boiler. 

In this burner configuration, fuel is injected directly into the combustion chamber and hence, one would initially categorize it as a nonpremixed burner. However, the overall combustion process is quite complex and involves features of nonpremixed, partially premixed, and stratified combustion, as well as the possibility that the autoignition of hot mixtures of fuel, air, and recirculated combushon products may play a role in stabilizing the flame. Thus, while one may start from simple concepts of nonpremixed turbulent flames, the inclusion of local exhnchon or flame lift-off quickly increases the physical and computational complexity of flames that begin with nonpremixed streams of fuel and oxidizer. 

For example, if the starting distance was 3 cm and the top of the inner blue cone is 6 cm, then the new position will be 9 cm above the burner top. Estimate the distance from the top of the burner to the wire gauze with the ruler and record this distance in Data Table 2. Turn off the flame. 

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