Induced Burners and Combustion - Part B 080205bB Flashcards
What type of burner would you find on most induced draft furnaces?
Open tube single port inshot burner
What type of burner would you find on most residential induced draft hot water heating boilers and why?
The tube type (ported tube) burner with different styles of porting is used because the design allows precise positioning in the combustion chamber
What does larger gas emission porting permit on an induced draft fan?
Creates primary air flow through the burner during operation
Describe an induced draft burner
This burner has no adjustable components on it and achieves various heat ratings in different appliances by using different orifice sizes or by being applied to staged firing models for appliances
How can you make adjustments to an induced draft burner?
With induced draft burners, often the only adjustment that can be made is to the regulator that controls the gas pressure delivered to the appliance
What kind of flame is used in most induced draft appliances?
Near neutral
Why are induced draft burner appliances noisier than natural draft?
Induced draft burners are noisy due to the velocity of the air/gas mixture moving through it
Appliances with what kind of burner require more thorough servicing?
Natural draft burner appliances
Why does air and fuel flow relatively well through induced draft burners?
Large primary air openings, fuel escape porting and smooth internal surfaces
What is a major difference between the induced draft and the atmospheric burner?
Induced draft burners will not have an air shutter
What induced draft burner does not always use venturi action?
Ported tube burner
What is one of the most important devices used for operation of an induced draft appliance?
The fan, which provides smooth and effective flow of the products of combustion through the appliance heat exchanger
What kind of spark does a spark igniter create?
High voltage, low current which is required to make it arc through the air space (high resistance)
What would happen if an excess of very cold air enters the firebox or if the flame were allowed to impinge on a cold metal surface?
Combustion is likely to start producing CO
A fan-assisted furnace may be common vented into a masonary chimney as long as what provision is made?
The chimney must also serve at least 1 draft-hood appliance
