CN109990611A - A system and method for efficient dust removal and waste heat recovery of electric furnace flue gas - Google Patents

Abstract

The invention discloses a high-efficiency dust removal and waste heat recovery system and method for electric furnace flue gas in the technical field of flue gas purification and waste heat recovery. The regenerative settling chamber, the waste heat boiler, the cyclone dust collector and the steam phase change removal tower are connected in sequence through pipelines. The steam promotes the growth and removal of PM2.5 fine particles, achieves efficient removal of fine particles from flue gas, and truly achieves the purpose of energy saving and emission reduction, and has a wide range of market application value.

Description

A system and method for efficient dust removal and waste heat recovery of electric furnace flue gas

technical field

The invention relates to the technical field of flue gas purification and waste heat recovery, in particular to a system and method for efficient dust removal and waste heat recovery of electric furnace flue gas.

Background technique

With the increasingly prominent problem of air pollution in my country, especially PM2.5 fine particles have brought great harm to people's life and health, it is necessary to further reduce the emission of particulate matter and improve the emission standard. With the further reduction of pollutants in the thermal power industry facing the constraints of diminishing marginal space and rising marginal costs, the focus of air pollution prevention and control should be shifted to non-electrical industries with higher pollutant emission intensity. In the future, the dust removal standards for non-electrical industries will be gradually improved.

Electric furnace dust is one of the main pollution sources in iron and steel enterprises. It has the characteristics of large emission, high flue gas temperature, fine dust and hydrophilicity. At present, the commonly used methods for dust removal of electric furnace gas are: mechanical dust removal, wet dust removal, filter dust removal and electrostatic dust removal. However, the removal efficiency of these dust removal equipment for the PM2.5 of the electric furnace flue gas is not high, so that the PM2.5 emission in the flue gas exceeds the standard, so it is urgent to design a removal and purification system for the PM2.5 of the electric furnace flue gas. Therefore, the present invention designs an efficient dust removal and waste heat recovery system and method for electric furnace flue gas to solve the above problems.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an efficient dust removal and waste heat recovery system and method for electric furnace flue gas, so as to solve the problem of the urgent need to design a PM2.5 removal and purification system for electric furnace flue gas proposed in the above background technology.

In order to achieve the above purpose, the present invention provides the following technical solutions: a system and method for efficient dust removal and waste heat recovery of electric furnace flue gas, including a regenerative settling chamber, a waste heat boiler, a cyclone dust collector and a steam phase change removal tower, the storage The thermal settling chamber, the waste heat boiler, the cyclone dust collector and the steam phase change removal tower are connected in sequence through pipes.

Preferably, a pressure relief valve is provided at the inlet end of the regenerative sedimentation chamber.

Preferably, a steam separator is provided at the steam output end of the waste heat boiler.

Preferably, the dust discharge port of the cyclone is provided with a vacuum cleaner.

Preferably, the steam phase change removal tower includes a pair of steam inlets, which are respectively arranged on both sides of the lower part of the removal tower, and a wire mesh demister is arranged on the upper part of the removal tower, and the upper part of the wire mesh demister is provided with flushing water system.

Preferably, a method for high-efficiency dust removal and waste heat recovery of electric furnace flue gas includes the following steps: the flue gas from the fourth hole of the electric furnace is tempered and settled by a regenerative settling chamber, and then sent to a waste heat boiler to conduct heat treatment on the heat of the high-temperature flue gas. Recover and generate steam; part of the generated steam is sent to the steam pipe network of the steel plant, and the other part is passed to the steam phase change removal tower behind the system; after the flue gas passes through the waste heat boiler, the temperature of the flue gas decreases, the volume decreases, and the flow rate decreases. Pre-dusting is carried out in the cyclone dust collector to remove fine particles larger than 5μm; the flue gas from the cyclone dust collector is then sent to the steam phase change removal tower, and the fine particles that are not removed in the flue gas are passed through the steam. Nucleation and condensation occurs in the saturated water vapor environment, and the grown dust-containing droplets are intercepted by the wire mesh demister inside the vapor phase change removal tower, and washed to the bottom of the removal under the action of flushing water. At the same time, the purified flue gas is sent to the chimney for discharge through the outlet of the vapor phase change removal tower.

Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention can not only realize the recovery of waste heat from flue gas, but also utilize the generated steam to promote the growth of PM2.5 fine particles by setting a waste heat boiler and a steam phase change removal tower. And remove, to achieve efficient removal of fine particles of flue gas, truly achieve the purpose of energy saving and emission reduction, has a wide range of market application value.

Description of drawings

In order to explain the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used for describing the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

Figure 1 is a schematic structural diagram of the present invention.

In the accompanying drawings, the list of components represented by each number is as follows:

1- Regenerative settling chamber, 2- Waste heat boiler, 3- Cyclone dust collector, 4- Steam phase change removal tower.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inside", " The orientation or positional relationship indicated by "outside" is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, so as to The specific orientation configuration and operation are therefore not to be construed as limitations of the present invention.

Please refer to FIG. 1, the present invention provides a technical solution: an electric furnace flue gas efficient dust removal and waste heat recovery system and method, including a regenerative settling chamber 1, a waste heat boiler 2, a cyclone dust collector 3 and a steam phase change removal tower 4. The regenerative settling chamber 1, the waste heat boiler 2, the cyclone dust collector 3 and the steam phase change removal tower 4 are sequentially connected through pipes.

Among them, the inlet end of the regenerative sedimentation chamber 1 is provided with a pressure relief valve to prevent blockage and explosion, the steam output end of the waste heat boiler 2 is provided with a water vapor separator to reduce water loss, and the ash discharge port of the cyclone dust collector 3 is provided with a The vacuum cleaner absorbs the fugitive dust generated during ash unloading. The steam phase change removal tower 4 includes a pair of steam inlets, which are respectively arranged on both sides of the lower part of the removal tower, and the upper part of the removal tower is provided with a wire mesh demister and a wire mesh demister. The upper part is equipped with a flushing water system to perform pulse flushing of the wire mesh demister.

A specific application of this embodiment is: the flue gas from the fourth hole of the electric furnace is tempered and settled by the regenerative settling chamber 1, and then leads to the waste heat boiler 2 to recover the heat of the high-temperature flue gas to generate steam; the generated steam One part is sent to the steam pipe network of the steel plant, and the other part is passed to the steam phase change removal tower 4 behind the system; after the flue gas passes through the waste heat boiler 2, the temperature of the flue gas decreases, the volume decreases, and the flow rate decreases. Pre-dust removal is performed to remove fine particles larger than 5 μm; the flue gas from the outlet of the cyclone dust collector 3 is then sent to the steam phase change removal tower 4, and the fine particles that are not removed in the flue gas are passed into the supersaturated water vapor environment formed by the steam Nucleation, condensation and growth occurred in the middle, and the grown dust-containing droplets were intercepted by the wire mesh demister inside the vapor phase transition removal tower 4, and washed to the bottom of the removal under the action of flushing water, and passed through the waste liquid discharge port. At the same time, the purified flue gas is sent to the chimney through the outlet of the vapor phase change removal tower 4 for discharge.

In the description of this specification, description with reference to the terms "one embodiment," "example," "specific example," etc. means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one aspect of the present invention. in one embodiment or example. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above-disclosed preferred embodiments of the present invention are provided only to help illustrate the present invention. The preferred embodiments do not exhaust all the details, nor do they limit the invention to only the described embodiments. Obviously, many modifications and variations are possible in light of the contents of this specification. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is to be limited only by the claims and their full scope and equivalents.

Claims (6)

1. An electric furnace flue gas efficient dust removal and waste heat recovery system, comprising a regenerative settling chamber (1), a waste heat boiler (2), a cyclone (3) and a vapor phase change removal tower (4), characterized in that : The regenerative settling chamber (1), the waste heat boiler (2), the cyclone dust collector (3) and the steam phase change removal tower (4) are sequentially connected through pipes. 2 . The high-efficiency dust removal and waste heat recovery system for electric furnace flue gas according to claim 1 , wherein a pressure relief valve is provided at the inlet end of the regenerative settling chamber ( 1 ). 3 . 3 . The high-efficiency dust removal and waste heat recovery system for electric furnace flue gas according to claim 1 , wherein the steam output end of the waste heat boiler ( 2 ) is provided with a water vapor separator. 4 . 4 . The high-efficiency dust removal and waste heat recovery system for electric furnace flue gas according to claim 1 , wherein a vacuum cleaner is provided at the ash discharge port of the cyclone dust collector ( 3 ). 5 . 5. The electric furnace flue gas high-efficiency dust removal and waste heat recovery system according to claim 1, characterized in that: the steam phase change removal tower (4) comprises a pair of steam inlets, which are respectively arranged in two lower parts of the removal tower. The upper part of the removal tower is provided with a wire mesh demister, and the upper part of the wire mesh demister is provided with a flushing water system. 6. A method for efficient dust removal and waste heat recovery of electric furnace flue gas, characterized in that it comprises the following steps: the flue gas coming out from the fourth hole of the electric furnace is tempered and settled through a regenerative settling chamber (1), and then leads to a waste heat boiler (1). 2) The heat of the high temperature flue gas is recovered to generate steam; part of the generated steam is sent to the steam pipe network of the steel plant, and the other part is passed to the steam phase change removal tower (4) behind the system; the flue gas passes through the waste heat boiler (2) ), the temperature of the flue gas decreases, the volume decreases, and the flow rate decreases, and pre-dusting is performed in the cyclone dust collector (3) to remove fine particles larger than 5 μm; the flue gas at the outlet of the cyclone dust collector (3) is then sent into the vapor phase Change removal tower (4), the fine particles that are not removed in the flue gas undergo nucleation, condensation and growth in the supersaturated water vapor environment formed by passing steam, and the grown dust-containing droplets pass through the steam phase change removal tower (4) The internal wire mesh demister intercepts it, flushes it to the bottom of the removal under the action of flushing water, and discharges it through the waste liquid discharge port. At the same time, the purified flue gas is sent to the outlet of the vapor phase change removal tower (4). Chimney exhaust.