Rooftoop
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| Gas Heating Burners | Induced Draft & Forced Draft
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| Induced Draft | 1. Pulls combustion gasses through the heat exchangers. 2. Slight negative pressure in the heat
exchanger.
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| Forced-Draft | 1. Combustion blower at the inlet of the heat exchanger and push combustion gases through the heat exchanger. 2. Positive pressure in the heat exchanger.
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| Purpose of the burner | To properly mix the primary air and gas, Where combustion takes place, Uses primary and secondary air,Primary air enters the burner with the gas, Secondary air is provided to ensure proper combustion, Gas is ignited by the pilot.
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| Primary Air and Secondary Air | Primary air enters the burner near the orifice, velocity to creating a low pressure area, forcing it into the combustion area, Primary air alone does not provide complete combustion. Secondary air is required
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| Venturi Function | Negative pressure draws in the primary air
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| Primary air can be adjusted using | Primary Air Shutters, two types: 1) butterfly 2) Rotating cylinder
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| Two General Classifications of Burners | 1. multi-port 2. mono-port
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| Types of Burners | 1) Cast Iron Burner with Slotted port
2) Stamped- steel slotted burner
3) Ribbon burner
4) In-shot burner
5) Up-shot burner
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| All these burners are known as atmospheric burner | The air for the burning is at atmospheric pressure
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| Multi-Port Burner Components | 1) Orifice 2) Carry-over port 3) Ports 4) Venturi 5) Mixing Tube 6) Burner Head
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| Single Port Burners Upshot & Inshot | The simplest and has one port, Most In-Shot burners are made out of aluminized steel,a crossover porting for flame retention and carryover to each main burner, no primary or secondary air adjustments
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| The Major advantage Mono-Port Burner | Their low cost and simplicity, used today induced draft and condensing furnaces
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| Mono-Port Burner Operate with 50% more Primary Air | To stabilize the flame and minimize lifting because of increase air, a flame retainer is used to provide a quenching surface to anchor the flame. Noisy than multi-port
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| Single Port Burners | 1) Upshot 2) Inshot
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| Carry Over Ports on some burners | slots it is necessary to have a flame carry over between burners, so a single ignition device can ignite all the burners,
Carry over ports are built into burners for this purpose and are shaped to span the gap between the burners.
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| Gas Manifolds | The manifold is a pipe through the gas flows to the burners. Gas orifices or spuds are mounted or threaded into the manifold. The manifold is attached to the outlet of the gas valve.
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| Gas Orifices | The orifice is a precisely drilled hole through which the gas flows from the manifold to the burners. The orifice is located in the spud. The spud is screwed into the manifold. The orifice allows the correct amount of gas into the burner
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| Gas Orifices Function | Control Gas flow inject primary air
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| Orifice Precautions | 1) Misaligned Orifice Spoils Primary injections 2) Don't cross-Thread the spud
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| Orifice Replacement | 1) Check the Orifice size for each installation 2) Replace new Orifice with proper size 3) Don't drill out or peen!!
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| Determining the Size of the Orifice | 1. Specific gravity of the gas 2. Heat content of the gas 3. Required Btu/hr required for each burner. The first two are determined by the type of gas. (natural gas or propane)
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To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
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Created by:
toolegit