Hot Sieving Electrostatic Precipitator for High-Temperature Particulate Removal
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Solution Overview
Problem
Conventional electrostatic precipitators are ineffective in removing particulate matter from high-temperature gaseous streams, particularly above 300°C, due to reduced resistivity of particulates and inability to capture fine and submicron particles, leading to inefficient particulate removal and increased operational costs.
Innovation Solution
A hot sieving electrostatic precipitator with grouped screens of alternating polarity, adjustable spacing, and enhanced corona discharge using spikes, along with acoustic cleaning and prioritized rapping to optimize particulate capture and reduce re-entrainment, allowing effective operation up to 1200°C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electrostatic precipitators are used to remove particulates from hot gaseous streams, then the device structure is simple and easy to manufacture, but the particulate removal effectiveness is poor due to reduced resistivity at high temperatures and inability to capture fine particles
Solution Approach 1:
The precipitator is divided into multiple sections with alternating charged and grounded screens. Each section independently captures particles, allowing the system to handle high temperatures effectively while maintaining simple individual component structures. The segmentation enables parallel processing of gas streams across multiple screen pairs.
Solution Approach 2:
Different regions of the precipitator have different screen configurations and spacing optimized for local conditions. The charged screens have specific aperture patterns and the grounded screens have complementary patterns, creating localized electric fields tailored for capturing particles of different sizes and charges at various positions in the device.
2Temperature
If conventional ESPs operate at temperatures above 300°C, then the operational temperature range is extended, but the charging effectiveness of particles decreases due to reduced resistivity
Solution Approach 1:
The precipitator employs alternating charged and grounded screens that create dynamic electric field patterns. The alternating polarity configuration ensures that as particles move through the device, they encounter multiple charging opportunities with varying field strengths, compensating for reduced resistivity at high temperatures through repeated charging cycles.
Solution Approach 2:
The alternating pattern of charged and grounded screens creates periodic electric field zones throughout the gas flow path. This periodic structure provides multiple discrete charging zones where particles can be charged and discharged in sequence, ensuring effective particle charging even when resistivity is reduced by high temperatures.
3Volume of stationary object
If large inter-electrode spacing is used in conventional ESPs, then the device volume is reduced, but fine and submicron particles are not charged well and escape without capture
Solution Approach 1:
The precipitator volume is segmented into multiple smaller charging zones created by alternating charged and grounded screens. Instead of relying on a single large spacing, the total effective charging distance is divided into multiple smaller intervals, each capable of charging fine particles effectively while maintaining compact overall dimensions.
Solution Approach 2:
The screen configurations use aperture patterns and spatial arrangements in multiple dimensions to create effective electric fields. The charged and grounded screens are positioned with specific aperture alignments that generate focused electric field regions, maximizing charging efficiency within limited spatial constraints without requiring large inter-electrode spacing.
4Ease of manufacture
If conventional ESP technology is used for hot flue gases, then the technology is simple to implement, but extremely large collection plates would be required making the technology cumbersome and prohibitively expensive
Solution Approach 1:
The collection function is segmented across multiple smaller grounded screens rather than requiring one or few large collection plates. Each grounded screen in the alternating sequence serves as a collection surface for particles charged by adjacent charged screens, distributing the collection area across many compact components that are easier to manufacture and install.
Solution Approach 2:
The grounded screens serve dual functions: they act as collection surfaces for charged particles and simultaneously serve as charging electrodes for particles in the next zone (where they become the charged reference). This multi-functionality reduces the need for separate dedicated collection plates, simplifying the overall structure while maintaining effectiveness.
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
Significantly improves particulate removal efficiency, including fine and submicron particles, by optimizing screen arrangement, charging, and cleaning processes, reducing operational costs and extending the applicability of electrostatic precipitation technology to higher temperature industrial processes.
Implementation Method 1
ESPs are used to separate particles from carrier gas by the application of an electrostatic charge
Implementation Method 2
it is known to enhance the effect of the charging screens by providing for a corona discharge by means of spikes provided to a first sieving screen
Implementation Method 3
ESPs are used to separate particles from carrier gas by the application of an electrostatic charge
Implementation Method 4
acoustic cleaning and prioritized rapping to optimize particulate capture
Data Source
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AI summary
An electrostatic precipitator and a method of removal of particulates from gaseous flows. A plurality of screens, secured in sets within a central chamber in a housing, comprise at least one set of electrically chargeable first screens and at least one set of electrically grounded second screens. For each set of chargeable screens, all the screens of the set are provided with an identical electrical charge, either positive or negative, and the set is provided with a plurality of spikes directed at the oncoming gaseous flow. At least one screen cleaning means selectively acts on the screens of each set. The precipitator can comprise a plurality of central chambers in a single housing or separate housings, and the chambers can be selectively activated or deactivated. The precipitator provides improved particulate removal from gaseous flows, including hot flows having temperatures up to at least 1200°C.