ASME BPVC.VI:2017 pdf free download

ASME BPVC.VI:2017 pdf free download

ASME BPVC.VI:2017 pdf free download.ASME Boiler and 2017 Pressure Vessel Code An lnternational Code.
4.2.2. I Pressure-Atomizing Burners (Gun Type). Pressure-atomizing burners gun type) are diided into two classes: high-pressure and low-pressure mechanical atomization.
(a) The high-pressure mechanical-atomizing type is characterized by an air lube, usually horizontal, with a pressurized oil supply centrally located in the tubc and arranged so that a spray of atomized oil is introduced at approximately I 00 psig (700 kPa) and mixed in thc combustion chamber with the airatream emerging from the air tube. The oil is supplied to the burner by a fuel delivery unit that serves as a pressure-flow-regulating device as well as a pumping device. Where electric ignition is employed, a high-voltage transformer is used to supply approximately 10.000 V to create an ignition arc across a pair ofclcctrodcs located above the nozzle. Where gas ignition is employed on a larger burner, a gas pilot is used. The firing rate is governed by the size of the nozzle used. Multiple nozzles are used on some of the larger burners, and variable flow nozzles are used on others. A low-fire start on a modulating burner that employs a variable flow nozzle is accomplished by supplying the oil at a reduced pressure. A low-Lire start on a multiple-nozzle burner is accomplished by permitting oil flow to only one or two of the nozzles.
(h) Thc low-pressure atomizing burner di&rs from thc high-pressure type mainly by having means for supplying a mixture ofoil and primary air to the burner nozzle. The air meeting the mixture in the fUrnace is “secondary air” that provides for complete combustion. The air pressure before mixing and thc pressure of the air-oil mixture vary with diflrent makes ofburncrs but are in the low range of I psig to 15 psig (7 kPa to 100 kPa) for air and 2 psig to 7 psig (14 kPa to 48 kPa) for the mixture. Capacity of the burners is viried by making pump stroke or orifice changes on the oil pumps. Steam-Atomizing Burners. Steam-atomizing burners usc steam to atomize heavy-grade fuel oil. Steam is usually supplied by the boiler being operated. Air-Atomizing Burners. Inthis eypcofburner. the compressed air or steam is used as the atomizing medium. An air compressor is usually provided as part of the burner, although the air may be supplied from another source. Horizontal Rotary Cup Burner. The horizontal rotary cup burner uses the principle of centrifUgal atomization. The oil is prepared for combustion by centrifugal force, which spins it offa cup rotating at high speed unto an airstream. causing the oil to break up into a spray. This type can be used with all grades of fuel oil. Modulated firing can be provided on these burners.