CN102448614B - Wet electrostatic precipitator system components - Google Patents

Abstract

The present invention relates to the use of corrosion-, temperature-and spark-resistant electrically conductive components in wet electrostatic precipitator systems (WESPs). In particular, the present invention is directed to the use of conductive composites in the manufacture of wet electrostatic precipitator system components.

Description

Wet electrostatic precipitator system components

technical field

The present invention relates to the use of corrosion resistant, temperature resistant and spark resistant conductive components in wet electrostatic precipitator systems (WESPs). In particular, the present invention is directed to the use of novel conductive composite materials for making wet electrostatic precipitator system components.

Background technique

Wet electrostatic precipitators have been used for many years to electrostatically remove dust, acid mist, and other particulates from water-saturated air and other gases. In WESP, water-saturated air laden with particles and/or mist flows into the area of the precipitator between the discharge electrode and the collector, where the particles and/or mist are charged by the corona emitted from the high voltage discharge electrode . As the water-saturated gas flows further within the WESP, the charged particulate matter and/or mist is electrostatically attracted to a grounded collection plate or collector electrode, where it is collected. Accumulated material is continuously washed off by water film irrigation and periodic flushing.

These systems are used to remove pollutants from gas streams exiting various industrial sources such as incinerators, wood product manufacturing, coke ovens, glass melting furnaces, non-ferrous metal smelters, coal-fired power plants, Forestry product equipment, food drying plants and petrochemical plants.

Traditionally, the collection surfaces and other parts of electrostatic precipitators exposed to the process airflow have been fabricated from carbon steel, stainless steel, corrosion and temperature resistant alloys, lead, and glass fiber reinforced plastics. However, such materials tend to corrode and/or degrade over time, especially when dust collectors are used in harsh environments. Carbon steel and stainless steel tend to corrode or erode in harsh acidic conditions. Reinforced plastics tend to erode and/or delaminate due to harsh corrosion conditions and localized high temperatures in the area of the spark.

Therefore, there is a need to manufacture components exposed to airflow within wet electrostatic precipitators that are not only corrosion resistant in harsh industrial environments, but also electrically conductive and withstand localized high temperatures due to sparks and arcs.

Contents of the invention

The present invention is concerned with providing a corrosion-resistant and heat-dissipating component for use in a wet electrostatic precipitator system. More specifically, the present invention provides conductive, corrosion-resistant, and spark-resistant composite materials for use in the manufacture of components such as those found in wet electrostatic precipitator systems.

According to one aspect of the present invention, there is provided a novel electrically conductive, corrosion resistant, temperature resistant composite material with good heat dissipation for use in the manufacture of components in wet electrostatic precipitator systems where the components are in direct contact with the process gas stream .

According to another aspect of the present invention, there is provided a novel collection surface for use in a wet electrostatic precipitator system, said collection surface being made of an electrically conductive, corrosion resistant and temperature resistant composite material with good heat dissipation properties to avoid degradation under typical spark/arc conditions.

According to yet another aspect of the present invention, there is provided a collection pipe for use in a wet electrostatic precipitator system, the collection pipe being made of an electrically conductive, corrosion and temperature resistant, spark/arc resistant composite material. Preferably, said collection tubes are formed in a bundle within said system.

According to yet another aspect of the present invention, there is provided a wet electrostatic precipitator system comprising at least one component made of an electrically conductive, corrosion and temperature resistant, spark/arc resistant composite material.

Description of drawings

A detailed description of preferred embodiments is provided hereinafter with reference to the accompanying drawings, in which:

Figures 1 and 2 are perspective views of a SonicKleen™ wet electrostatic precipitator system.

In the figures, a preferred embodiment of the invention is illustrated by way of example. It should be expressly understood that the description and figures are for illustration only and to aid in understanding, and are not intended as a definition of the limits of the invention. In particular, electrostatic precipitators may be of any desired orientation, configuration, or type, including upflow, horizontal flow, downflow, tube, or plate.

detailed description

The conductive composite employed here is one designed for highly corrosive operating conditions with elevated temperatures including dry and saturated fog environments. The composite material is a blend of carbonized glass fibers and thermoset resins developed for applications subject to corona voltage flashover, sparking, erosion, corrosion, and arcing, including wet electrostatic precipitators.

Specifically, the composite material includes carbonized glass fibers and within a thermoset resin, wherein the extremely strong molecular building blocks form a fully cross-linked structure bonded to each other and formed as interconnections. The resultant network has been proven to withstand the high voltage currents following corona in the tubes of electrostatic precipitators, achieving voltage flashover without pitting the conductive hybrid composite. This spark resistance and arcing can occur at approximately 60 to 95 KV at up to 500 to 1000 mA for approximately 1 millisecond. The composite also withstands sustained arcs lasting up to 4 to 5 seconds. These properties are highly desirable for minimizing corrosion and limiting high intensity heat generation, and for preventing structural, mechanical or chemical changes to conductive hybrid composites.

Carbonized fibers woven into a sleeve of seamless biaxial material create a dense network that imparts electrical conductivity and thermal dispersion within the thermoset resin.

The strong molecular building blocks form a fully cross-linked structure bonded to each other and formed into interconnections, resulting in a three-dimensional network, stitched through the thickness of the laminate. Carbon fibers are woven into seamless biaxial and triaxial materials. This arrangement imparts excellent electrical conductivity and excellent heat dispersion through lamination.

In addition to conductive properties and excellent corrosion resistance, conductive hybrid composites offer further advantages as materials of construction, reducing dead weight by half or more due to the lightweight and high-strength mass of carbonized glass fibers, which This leads to an economical advantage which is especially advantageous before installation of tube bundles made of stainless steel or even higher grades of titanium.

The composite material can be prepared by weaving, stitching, alignment via vibrations using frequencies, while the material can be formed into tubes by prior art processes known as vacuum impregnation, pultrusion, filament winding, and high pressure processing. and slice shapes.

By improving upon prior art thermoset resin and carbonized glass fiber composites that could not withstand corona voltage flashovers and arcs up to 100,000 volts, the conductive composite overcomes the need for highly corrosive environments, saturated fog, and elevated Corrosion problems that damage stainless steel, alloys, titanium at high temperatures.

Conductive hybrids suitable for use in this application are described in co-pending U.S. Provisional Patent Application No. 60/886,718, filed January 26, 2007, and U.S. Patent Application No. 12/136,362, filed in the name of Crawford Dewar. Composite Materials, the disclosures of the above applications are incorporated herein by reference.

In one embodiment, the composite material of the present invention is particularly suitable for the manufacture of collector tubes used in wet electrostatic precipitators, which can be cylindrical or hexagonal or plate-shaped. One such type of wet electrostatic precipitator is known as the SonicKleen™ WESP and is shown in Figures 1 and 2. The precipitator has incorporated rigid mast electrode technology into it, which concentrates the ionizing corona in a specific area within the electrode tube rather than distributing it along the entire length. It has been recognized and shown that the use of collector tubes of the composite materials described herein in such precipitators increases the durability of the tubes because they are less prone to corrosion and corrosion than traditionally used materials such as stainless steel, lead, carbon, etc. Spark/arc damage. It has also been shown that the composite material can withstand the greater and harsher environmental conditions typically encountered in industrial gas purification applications than conventional materials currently in use.

The composite materials described herein can be used to fabricate components used in wet electrostatic precipitator systems that can be used in a variety of applications such as, but not limited to, chemical incinerators, textile processing, pulp and paper, Coke ovens, hog fuel boilers, blue haze abatement, plywood and particle board or other biomass dryers, glass melting furnaces, tin chloride collection, sulfur oxide control, fly ash control, pharmaceutical processes, detergent drying waste energy generation, distilled wine and beer, phosphorus furnace emissions, silicon manufacturing, power plant emissions, ammonia removal, phosphate fertilizer production, phosphoric acid production, waste liquid incinerators, solid waste incinerators, grain drying, sulfuric acid plants, sludge ash Chemical, rotary kiln purification, cement plant, waste wood, acid mist, vapor compression organic matter, metal surface finishing, paint coating, chemical point discharge, and petrochemical plants, etc.

Those skilled in the art will understand that the composites of the present invention may be used to fabricate any component of a wet electrostatic precipitator, and particularly those components that come into direct contact with the process gas stream. The composites of the present invention can withstand corona voltage flashover and arcing at up to 100,000 volts at high temperatures (200°F) for long periods of time, and at localized areas up to 1200°F for short periods of time. The material is electrically conductive, corrosion-resistant, and temperature-resistant even in the harsh environments encountered in industrial gas purification applications.

public profile

In a summary of the present disclosure, the present invention provides a novel hybrid conductive composite for use in the manufacture of components of wet electrostatic precipitators that are directly exposed to the process air flow. Modifications may be made within the scope of the invention.

Claims (2)

1. A wet electrostatic precipitator comprising a component which is a collection tube or a bundle of collection tubes made of conductive, corrosion-resistant and spark-resistant and/or temperature-resistant composite material or collecting surface, said composite material essentially comprising carbonized glass fibers within a thermoset resin in a cross-linked structure or carbonized fibers woven into a seamless biaxial tube of material within a thermoset resin. 2. The precipitator of claim 1 , wherein the components are designed to be in direct contact with process gas flow through the electrostatic precipitator.