Causes of shorter delayed coker heater runs reported
- Process Improvement Engineering, Metairie, LA (US)
Feed interruptions and localized high heat fluxes are common causes of shortened delayed coker heater run lengths. These causes were discussed by operators of delayed coking units who attended a delayed coking seminar held by Process Improvement Engineering in New Orleans in November 1989. Feed interruptions can cause shortened heater run lengths because heater tube-skin temperatures can rise whenever feed flow is reduced or stopped. The higher tube-skin temperatures accelerate coke deposition on the heater tubes, shortening the run length of the heater. Examples are presented that illustrate how feed can be interrupted by inadequate draining of a coke drum, level control problems in the fractionator bottom, a plugged flow-meter orifice, and by reduced steam supply to a steam-turbine-driven feed pump. Localized high heat fluxes can cause localized heavy coking on heater tubes. High heat fluxes can be generated by attempts to reduce energy consumption by reducing the excess air in fired heaters and by plugged burner tips. One cause of burner tip lugging is vacuum off gas in the coking heater fuel. Thorough decoking of heater tubes is necessary to achieve long heater run lengths. The procedure for steam spalling of heater tubes to decoke them is also reviewed.reviewed.
- OSTI ID:
- 7017118
- Journal Information:
- Oil and Gas Journal; (USA), Vol. 88:7; ISSN 0030-1388
- Country of Publication:
- United States
- Language:
- English
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01 COAL, LIGNITE, AND PEAT
42 ENGINEERING
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COKE
FLOWMETERS
PETROLEUM PRODUCTS
PLUGGING
STEAM TURBINES
INDUSTRIAL PLANTS
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MEASURING INSTRUMENTS
METERS
TURBINES
TURBOMACHINERY
020400* - Petroleum- Processing
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420400 - Engineering- Heat Transfer & Fluid Flow