Cylindrical Combustion Grate Roller Cooling Duct Design
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Solution Overview
Problem
Combustion and incineration furnace rollers face severe thermal stresses due to high temperatures, leading to dimensional variations, reduced service life, incomplete waste combustion, and inefficient air distribution, with existing cooling solutions either causing deformations or inadequate cooling.
Innovation Solution
A roller design featuring a cylindrical framework with a cooling fluid passage duct composed of coaxial hollow rings and connecting bridges, allowing uniform cooling and minimizing thermal expansions, along with a simple manufacturing and assembly process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the temperature in the hearth is increased to achieve complete waste combustion, then combustion efficiency is improved, but thermal stresses on the bars increase causing dimensional variations and reduced service life
Solution Approach 1:
The roller is divided into multiple modular bars arranged in a circular pattern, allowing individual bar replacement without replacing the entire roller. This segmentation enables maintenance operations while maintaining high temperature operation for complete combustion.
Solution Approach 2:
The invention changes the material parameter by using thermally resistant materials with high melting points and low thermal expansion coefficients for the bars and framework. This allows the system to operate at high temperatures for complete combustion while minimizing thermal stress effects.
2Reliability
If a cooling device is added to maintain bar temperature, then thermal stresses are reduced, but device complexity increases
Solution Approach 1:
The roller structure serves multiple functions simultaneously: the bars provide both waste support and cooling fluid passage, the framework provides structural support and cooling fluid distribution, and the entire assembly maintains both mechanical strength and thermal management. This multi-functionality eliminates the need for separate cooling components.
Solution Approach 2:
The cooling fluid passage ducts are nested within the bar and framework structures themselves, utilizing the existing roller geometry for cooling fluid flow. This integration eliminates external cooling components while maintaining effective thermal management.
3Temperature
If hollow longitudinal bars are used for cooling fluid passage, then cooling effectiveness is improved, but deformation risks increase leading to blocking and clinker falling
Solution Approach 1:
The bars and framework are constructed from composite or multi-layer structures combining materials with complementary properties - high strength-to-weight ratio, high thermal resistance, and controlled thermal expansion. This composite construction maintains structural stability while accommodating thermal stresses from cooling fluid passage.
Solution Approach 2:
The roller system incorporates dynamic elements including adjustable bar positions and flexible cooling fluid flow control, allowing the system to adapt to thermal conditions in real-time and prevent deformation-induced blocking.
4Temperature
If a helical winding duct is used for uniform cooling, then cooling uniformity is improved, but manufacturing and installation complexity increases
Solution Approach 1:
The cooling fluid distribution system is segmented into modular components - separate duct sections for different roller zones, removable bar assemblies with integrated cooling passages, and modular framework sections. This segmentation enables simple manufacturing of individual components that can be assembled to achieve uniform cooling across the entire roller.
Solution Approach 2:
Instead of using a complex helical three-dimensional winding, the invention achieves uniform cooling by distributing cooling ducts systematically across the radial and axial dimensions of the roller, creating a grid-like pattern that is simpler to manufacture while achieving the same cooling uniformity.
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 solution provides a roller resistant to temperature conditions, reducing maintenance needs, enabling complete waste combustion, and ensuring efficient air distribution while maintaining structural integrity.
Implementation Method 1
a cooling fluid passage duct (3) composed of: a series of hollow rings (6), coaxial with axis A, distributed over the length of said roller
Implementation Method 2
bridges (9) connecting the fluid outlet of one ring to the fluid inlet of the next ring
Implementation Method 3
a roller for an oven grid, intended to be mounted in rotation in the hearth of said oven around an axis A longitudinal to said roller
Implementation Method 4
the bars on which the waste rests are subjected to very severe thermal stresses due to the high level of temperatures prevailing in the combustion zone and the significant temperature differences between the heating due to radiation and contact with the materials in combustion
Implementation Method 5
combustion and/or incineration furnace rollers
Implementation Method 6
Air distribution: the air passing through the rollers is then no longer distributed properly
Data Source
Figure 1~2
Figure 3~8
Figure 9a~9b
AI summary
The roller (1) has a combustible support surface mounted on a metallic hollow structure (2) forming a cylindrical cage, and a passage pipe (3) for allowing passage of cooling fluid. A series of hollow rings (6) is coaxial to an axis and is distributed on length of the roller, where each ring is provided with a fluid inlet (7) and a fluid outlet (8). Inter-ring bridges (9) connect the fluid outlet of the ring to the fluid inlet so as to form cooling fluid passage circuit wrapped around the structure.