Electric air heater
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current electric air heater systems are limited in heating large volumes of gas to high temperatures with low pressure drop, as they have small channel sizes, direct contact between heating elements and gases, leading to overheating and premature failure, and are unsuitable for corrosive or flammable gases.
Innovation Solution
An electric air heater system with a refractory insulation layer and multiple tubes arranged in bundles, each with fins and a heating element, allowing for radiative heat transfer and convective heat transfer from tubes to gases, enabling high-temperature heating of large volumes of air or fluids with reduced pressure drop and preventing overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If direct contact between heating elements and process gases is used, then heat transfer efficiency is improved, but heating elements overheat and fail prematurely
Solution Approach 1:
The patent introduces tubes as an intermediary medium between the heating elements and process gases. The heating elements heat the tubes, and the tubes in turn heat the process gases through their outer surfaces. This mediator approach allows efficient heat transfer while protecting the heating elements from direct exposure to corrosive and high-temperature gases, preventing overheating and premature failure.
2Temperature
If small channel sizes are used in heater assemblies, then heating element temperature control is improved, but the ability to heat large volumes of air is reduced
Solution Approach 1:
The patent transitions from heating large volumes of air through many small channels to heating through large-diameter tubes. By utilizing the radial dimension for heat transfer (heating from the tube wall outward to the air flowing through), the system can accommodate large tube diameters that provide large cross-sectional areas for air flow while maintaining effective heat transfer through the tube walls.
3Use of energy by moving object
If process gases flow directly over heating elements, then heat transfer is improved, but heating elements vibrate and may short circuit or break
Solution Approach 1:
The tubes serve as a protective intermediary between the heating elements and the flowing process gases. The heating elements remain stationary inside the tubes, eliminating vibration and short circuiting risks, while still achieving effective heat transfer to the gases through the tube walls.
4Productivity
If conventional heater assemblies with high flow resistance are used, then heating efficiency is improved, but pressure drop increases
Solution Approach 1:
The patent changes the flow channel parameters by using large-diameter tubes instead of small channels. This parameter change reduces flow resistance and pressure drop while maintaining heating efficiency through the tube wall heat transfer mechanism. The large tube diameters allow for high volumetric flow rates with minimal pressure loss.
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 system effectively heats large volumes of air or fluids to temperatures exceeding 343°C, with improved watt density and reduced risk of overheating, allowing for the use of corrosive or flammable gases and easy maintenance, while maintaining a low pressure drop.
Implementation Method 1
a heating element axially through a hollow interior of the tube
Implementation Method 2
enabling high-temperature heating of large volumes of air or fluids
Implementation Method 3
a refractory insulation layer in tight communication with the outer casing
Data Source
AI summary
An electric air heater system including a first electric air heater module. The first electric air heater module including an outer casing having an inner surface, a first end, and a second end; a refractory insulation layer in tight communication with the outer casing; an inner cavity within the refractory insulation layer; and a plurality of tubes extending through the inner cavity from the first end to the second end, the plurality of tubes each having an exterior surface. Each tube is fixed relative to the outer casing at the first end, and each tube has an electrical connection disposed at the first end. The plurality of tubes is arranged into one or more bundles of tubes, where each bundle includes two or more tubes having a plurality of fins extending radially from the exterior surface, and a heating element axially through a hollow interior of the tube.