Vertical drum-type boiler with enhanced circulation
OwnerArkadiy M. Gurevichinventor
Life of this patent
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Abstract
A vertical boiler with horizontal evaporator tubes is provided. The evaporator is divided into two sections, which are connected in parallel to the drum. The first evaporator section relies on the feedwater pump to provide forced circulation. The second evaporator section relies primarily on natural circulation but may also be assisted by the feedwater pump. This design provides a vertical boiler which is reliable under all operating conditions, including start-up, transient conditions, and steady state conditions, without requiring the use of circulating pumps or an auxiliary energy source (steam, water, gas, etc.).
Claims15
An evaporator system, comprising:
- a drum;
- a substantially vertical gas duct through which hot gas can pass;
- first and second evaporator sections located in said gas duct, each of said evaporator sections defining an inlet and an outlet and including substantially horizontal heat-absorbing tubes;
- a feedwater pump in fluid communication with the inlet of said first evaporator section;
- a downcomer from said drum in fluid communication with the inlet of said second evaporator section;
- a connecting line providing fluid communication between the outlet of said first evaporator section and said drum;
- and
- a riser providing fluid communication between the outlet of said second evaporator section and said drum, wherein said first and second evaporator sections are connected in parallel to said drum through said connecting line and said riser.
An evaporator system, comprising:
- a drum;
- a substantially vertical gas duct through which hot gas can pass;
- first and second evaporator sections located in said gas duct, each of said evaporator sections defining an inlet and an outlet and including substantially horizontal heat-absorbing tubes;
- a downcomer from said drum to the inlet of said second evaporator section;
- a riser from the outlet of said second evaporator section to said drum;
- a feedwater pump in communication with the inlet of said first evaporator section;
- and
- a connecting line providing fluid communication from the outlet of said first evaporator section to said drum.
A method for enhancing the circulation in a drum-type waste heat recovery boiler having substantially horizontal heat-absorbing evaporator tubes, comprising the steps of:
- dividing the heat-absorbing tubes into a first evaporator section and a second evaporator section;
- wherein said first and second evaporator sections are connected in parallel with the drum;
- providing forced circulation in said first evaporator section, using the driving head of a feedwater pump;
- and
- relying primarily on natural circulation in said second evaporator section.
Dependencies are inferred from the claim text.