Boiler for generating hot water or steam
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Solution Overview
Problem
Traditional pressurized steam generators face issues with unburned material buildup, flame backflows, smoke leaks, pressure wave propagation, high space occupation, and high pollutant emissions, particularly carbon monoxide and nitrogen oxides, due to their premix burner and fan design.
Innovation Solution
A boiler design with a combustion system that uses a premixing device with a mixer body and a one-way valve to control pressure waves, reducing pressure in the combustion chamber, and incorporating an exhaust gas heat exchanger to minimize NOx emissions and prevent external gas leaks, while optimizing the burner's placement to reduce space occupation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a premix burner with fan is used to increase pressure in the combustion chamber, then combustion efficiency is improved, but unburned material buildup occurs in the event of flue obstructions
Solution Approach 1:
The patent inverts the traditional pressurized combustion approach by using a suction fan instead of a blow fan. The suction fan creates negative pressure (suction) in the combustion chamber rather than positive pressure (blowing), which reverses the pressure gradient and prevents unburned material buildup while maintaining combustion efficiency.
Solution Approach 2:
The patent converts the potentially harmful suction effect (which could draw in unburned material) into a beneficial feature by positioning the suction fan at the exhaust end to create controlled negative pressure that draws combustion gases through the heat exchange tubes, improving heat transfer while preventing material accumulation.
2Productivity
If a premix burner with fan is used to increase pressure in the combustion chamber, then combustion efficiency is improved, but flame backflows toward the external environment occur
Solution Approach 1:
The patent reverses the pressure gradient by using suction instead of blowing, creating negative pressure in the combustion chamber that prevents flame backflow toward the external environment while maintaining the premix combustion efficiency.
3Productivity
If a premix burner with fan is used to increase pressure in the combustion chamber, then combustion efficiency is improved, but smoke leaks through gaskets in the door and fume collection chamber
Solution Approach 1:
The patent inverts the pressure approach by using suction to create negative pressure in the combustion chamber, which prevents smoke from leaking through gaskets and seals, while the premix burner maintains high combustion efficiency.
4Productivity
If a premix burner with fan is used to increase pressure in the combustion chamber, then combustion efficiency is improved, but pressure wave propagation causes noise during ignition phases
Solution Approach 1:
The patent reverses the pressure gradient by using suction instead of blowing, which dampens pressure wave propagation during ignition phases and reduces noise, while maintaining premix combustion efficiency through proper air-gas mixing.
5Productivity
If a premix burner with fan and Venturi tube is used, then combustion efficiency is improved, but space occupation at the door increases
Solution Approach 1:
The patent extracts the fan from the door assembly and relocates it to the exhaust end of the boiler, reducing space occupation at the door while maintaining the premix combustion efficiency through separate air and gas supply systems.
Solution Approach 2:
The patent segments the combustion system into separate air supply and gas supply pathways, eliminating the need for a large Venturi tube assembly at the door and reducing space occupation while maintaining mixing efficiency through staged combustion.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The boiler effectively prevents unburned material buildup, reduces NOx emissions, eliminates flame backflows and pressure wave propagation, and minimizes space requirements, ensuring reliable, safe, and efficient operation with low pollutant emissions.
Implementation Method 1
a device for mixing air and gas which is constituted by a Venturi tube provided with an axial inlet connected to an air supply duct, a lateral inlet connected to a gas supply duct
Implementation Method 2
a fan, which makes it possible to continue the mixing of air and gas which is done inside the Venturi tube and to send the air/gas mixture under pressure to the combustion head
Implementation Method 3
the flame bursts, produced by the combustion head of a burner, located at one end of the combustion chamber
Implementation Method 4
The hot combustion gases generated in the combustion chamber are channeled into heat exchange tubes that axially pass through the heating chamber, so that the hot exhaust gases can exchange heat with the water contained in the heating chamber
Data Source
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AI summary
A boiler for generating hot water or steam, which comprises a containment enclosure (2) which defines a heating chamber (3), which contains the water to be heated and which accommodates a furnace (5), which defines a combustion chamber (6) provided with a burner (7) provided with a combustion head (8) and a device (9) for premixing air and gas; the combustion chamber (6) is connected to a plurality of heat exchange tubes (11), which pass through the combustion chamber (3) and lead into an exhaust gas collection chamber (12) which is connected to a flue (13); the premixing device (9) comprises a mixer body (16) accommodated axially in an air supply duct (17) and having at least one gas delivery opening (19); means are furthermore provided which are adapted to create a lower pressure in the combustion chamber (6) with respect to the external ambient pressure.