Ultra-low emission device for non-ferrous smelting flue gas

Abstract

The invention discloses a non-ferrous smelting flue gas ultra-low emission device which comprises a flue gas pipeline, the flue gas pipeline sequentially penetrates through an absorption tower and an electric dust remover in the flue gas emission direction and then enters a chimney, flue gas is exhausted through the chimney, and a first purification device is arranged in the absorption tower; a second purification device and an on-line monitoring system are further arranged in the flue gas pipeline, the on-line monitoring system is located between the electric dust remover and the chimney, and the on-line monitoring system is connected with a controller for controlling the second purification device to start and stop. The system has the beneficial effects that the flue gas is monitored in real time through the on-line monitoring system, meanwhile, monitoring indexes are interlocked with the second purification device, when it is monitored that the flue gas indexes exceed the standard, the second purification device is interlocked and started, pollutants are rapidly atomized, sprayed and absorbed, and the monitoring indexes and the content of the pollutants are reduced to be within the controllable range.

Description

Technical Field

[0001] The present invention relates to the technical field of waste gas treatment and emission of industrial and mining enterprises, and in particular to an ultra-low emission device for non-ferrous smelting flue gas. Background Art

[0002] Before being discharged, waste gas needs to be treated harmlessly and pass the test.

[0003] The patent with the announcement number "CN209093100U" discloses "a tail gas spray absorption treatment device", including a spray absorption tower, the spray absorption tower contains spray liquid, the spray absorption tower includes a first spray chamber and a second spray chamber, an air inlet pipe is arranged on one side of the first spray chamber, an air outlet pipe is arranged on one side of the second spray chamber, a gas-liquid separator is arranged in the second spray chamber, and the tail gas in the air inlet pipe passes through the first spray chamber, the second spray chamber, the gas-liquid separator and the air outlet pipe in sequence according to the flow direction after entering the spray absorption tower, and a spray liquid circulation pipeline for circulating the spray liquid to the first spray chamber and the second spray chamber is arranged in the spray absorption tower. This scheme uses two spray chambers to be activated at the same time, thereby reducing the content of harmful substances in the exhaust gas to meet the environmental protection requirements, but the exhaust gas discharge of the enterprise changes in real time with the production conditions. When the exhaust gas discharge is small, it will lead to redundant waste of purification function.

[0004] To this end, our company has proposed an ultra-low emission device for non-ferrous smelting flue gas. Summary of the invention

[0005] The object of the present invention is to provide an ultra-low emission device for non-ferrous smelting flue gas, which can respond quickly to the exhaust gas discharge volume to ensure that the harmful substance content of the exhaust gas meets the requirements.

[0006] To achieve the above object, the present invention adopts the following technical solutions: A non-ferrous smelting flue gas ultra-low emission device comprises a flue gas duct, wherein the flue gas duct passes through an absorption tower and an electrostatic precipitator in sequence along the emission direction of the flue gas, enters a chimney and discharges the flue gas through the chimney, a first purification device is arranged in the absorption tower, a second purification device and an online monitoring system are also arranged in the flue gas duct, the online monitoring system is located between the electrostatic precipitator and the chimney, and the online monitoring system is connected to a controller for controlling the start and stop of the second purification device.

[0007] Preferably, the first purification device is a first spray pipe located in the absorption tower, the first spray pipe is connected to one end of the first liquid inlet pipeline, the other end of the first liquid inlet pipeline is connected to the bottom of the absorption tower, and a circulation pump is provided on the first liquid inlet pipeline.

[0008] Preferably, the second purification device is located between the absorption tower and the electrostatic precipitator.

[0009] Preferably, the second purification device is one or more atomizers arranged in parallel, the atomizers are connected to the air inlet pipeline and the discharge end of the second liquid inlet pipeline, the feed end of the air inlet pipeline is connected to the air storage tank, a valve is provided on the air inlet pipeline, the feed end of the second liquid inlet pipeline is connected to the absorption liquid storage tank, and an absorption liquid spray pump is provided on the second liquid inlet pipeline.

[0010] Preferably, the atomizer is connected to a feed pipeline, and the outlets of the air inlet pipeline and the second liquid inlet pipeline are both connected to the atomizer through the feed pipeline.

[0011] Preferably, a first recovery pipe connected to an absorption tower is provided at the bottom of the electrostatic precipitator.

[0012] Preferably, the device further comprises a decomposition tower, a second recovery pipeline is provided between the decomposition tower and the circulation pump, and the second recovery pipeline is connected to a second spray pipe located inside the decomposition tower.

[0013] Preferably, a third liquid inlet pipeline is further provided between the bottom of the analysis tower and the absorption tower, the third liquid inlet pipeline is connected to a third spray pipe located in the absorption tower, and a recovery pump is provided on the third liquid inlet pipeline.

[0014] The beneficial effects of the present invention are: 1. The flue gas is monitored in real time through the online monitoring system. At the same time, the monitoring index is interlocked with the second purification device. When the flue gas index is detected to be excessive, the second purification device is interlocked and started, and the pollutants are quickly absorbed by atomizing spray, reducing the monitoring index and pollutant content to a controllable range.

[0015] 2. The atomized absorption liquid of the second purification device is sprayed directly into the flue, without the need to modify the overall purification process and purification device, with little impact on the overall process, and the absorption liquid can be recycled; the absorption liquid is in direct contact with the flue gas and can quickly act on the pollutants, with a fast response speed, reducing the risk of exhaust gas exceeding the standard and reducing the occurrence of environmental accidents.

[0016] 3. Through the setting of the analysis tower, the spray liquid in the absorption tower can be reduced. After the pollutants inside it are reduced, the spray liquid can be reused, reducing the operating costs of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a pipeline schematic diagram of the present invention; Figure 2 is a cross-sectional view of a second purification device; Figure 3 This is a pipeline schematic diagram of Example 2; Figure 4 This is a pipeline schematic diagram of Example 3.

[0018] The drawings are only used for illustrative purposes and should not be construed as limitations on this patent. In order to better illustrate this embodiment, some parts of the drawings may be omitted, enlarged, or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings.

[0020] Embodiment 1 like Figure 1 As shown, a non-ferrous smelting flue gas ultra-low emission device includes a flue gas duct 20. The flue gas duct 20 passes through the absorption tower 2 and the electrostatic precipitator 8 in the emission direction of the flue gas in sequence and enters the chimney 10 and discharges the flue gas through the chimney 10. A first purification device is arranged in the absorption tower 2. A second purification device and an online monitoring system 9 are also arranged in the flue gas duct 20. The online monitoring system 9 is located between the electrostatic precipitator 8 and the chimney 10. The online monitoring system 9 is connected to a controller for controlling the start and stop of the second purification device. During the normal emission of flue gas, it is purified and discharged by the first purification device, and the emission is ensured to be qualified by the online monitoring system 9; when there are many harmful substances in the flue gas and the online monitoring system 9 detects that the emission is unqualified, the second purification device is started to purify the flue gas for the second time to ensure that the emission is qualified. The online monitoring system 9 is an existing conventional monitoring technology and will not be described in detail in this embodiment.

[0021] The first purification device is a first spray pipe 22 located in the absorption tower 2, the first spray pipe 22 is connected to one end of the first liquid inlet pipeline 21, the other end of the first liquid inlet pipeline 21 is connected to the bottom of the absorption tower 2, and a circulation pump 1 is provided on the first liquid inlet pipeline 21. Under the action of the circulation pump 1, the absorption liquid is sprayed through the first spray pipe 22 to absorb pollutants in the flue gas, and the absorption liquid after adsorbing the flue gas drops to the bottom of the absorption tower 2, and is circulated under the action of the circulation pump 1.

[0022] The second purification device is located between the absorption tower 2 and the electrostatic precipitator 8, and can perform secondary purification on the flue gas.

[0023] like Figure 2As shown, the second purification device is three atomizers 6 arranged in parallel, the atomizer 6 is connected to the discharge end of the air inlet pipeline 23 and the second liquid inlet pipeline 24, the feed end of the air inlet pipeline 23 is connected to the gas storage tank 3, the air inlet pipeline 23 is provided with a valve 11, the valve 11 is a pneumatic valve, the feed end of the second liquid inlet pipeline 24 is connected to the absorption liquid storage tank 4, and the second liquid inlet pipeline 4 is provided with an absorption liquid spray pump 5. The atomizer 6 is connected to the feed pipeline 25 (i.e., the spray gun), and the discharge ports of the air inlet pipeline 23 and the second liquid inlet pipeline 24 are both connected to the atomizer 6 through the feed pipeline 25. The atomizing nozzle used in this embodiment is a FLOMAX air atomizing nozzle, and a dual-fluid atomizing spray gun is used to atomize the absorption liquid to 50~100μm, thereby increasing the reaction rate and being able to respond quickly when harmful substances in the flue gas exceed the standard. In this embodiment, the absorption liquid in the absorption liquid storage tank 4 is liquid alkali, and compressed air is stored in the gas storage tank 3.

[0024] The bottom of the electrostatic precipitator 8 is provided with a first recovery pipe 7 connected to the absorption tower 2. The electrostatic precipitator 8 is a wet electrostatic precipitator (made of fiberglass). The absorption liquid sprayed by the atomizer 6 enters the electrostatic precipitator 8 along the flue gas pipe 20 and after being collected, flows into the absorption tower 2 along the first recovery pipe 7 for recycling.

[0025] In some embodiments, in order to avoid the absorption liquid being saturated with harmful substances after repeated use, resulting in a decrease in purification effect, a desorption tower 31 is also provided, and a second recovery pipeline 32 is provided between the desorption tower 31 and the circulation pump 1, and the second recovery pipeline 32 is connected to the second spray pipe 34 located inside the desorption tower 21. A third liquid inlet pipeline 35 is also provided between the bottom of the desorption tower 31 and the absorption tower 2, and the third liquid inlet pipeline 35 is connected to the third spray pipe 36 located in the absorption tower 2, and a recovery pump 33 is provided on the third liquid inlet pipeline 35. The circulation pump 1 can be connected to the first liquid inlet pipeline 21 and the second recovery pipeline 32 through a three-way valve, and electromagnetic valves for controlling the on-off can be respectively set on the two pipelines. When the absorption liquid needs to be reduced, the second recovery pipeline 32 is a passage, and the first liquid inlet pipeline 21 is closed. At this time, the circulating absorption liquid enters the absorption tower 2 along the recovery pump 33, the third liquid inlet pipeline 35, and the second spray pipe 34 (the principle of reducing the absorption liquid in the analysis tower 21 is: when the harmful substance in the exhaust gas is sulfur dioxide, the reduction absorption liquid absorbs sulfur dioxide at a low temperature (10°C to 50°C), and then enters the analysis tower and is heated by a heat exchanger (100°C to 135°C). The sulfur dioxide in the reduction absorbent is released, and the released sulfur dioxide is sent to the acid making system for acid making, and the reduction absorption liquid returns to the absorption tower to absorb sulfur dioxide); when the absorption liquid does not need to be reduced, the second recovery pipeline 32 is closed, and the first liquid inlet pipeline 21 is a passage. Figure 1As shown, the first spray pipe 22 and the second spray pipe 34 have different heights. When arranging them, it is necessary to arrange them crosswise in the top view to avoid the spray pipe at the lower position interfering with the spraying of the spray pipe at the higher position. In some embodiments, the first spray pipe 22 and the second spray pipe 34 can also be set as one pipe.

[0026] In this embodiment, the circulation pump 1, the recovery pump 33, and the absorption liquid spray pump 5 are all in a group of two, one for backup and the other for use, to avoid shutdown of the purification device due to pump failure.

[0027] This device adds an atomizing spray device to the flue gas outlet of the flue gas absorption tower. The atomizing device directly sprays the high-concentration absorption liquid into the flue to quickly absorb the pollutants in the flue gas, thereby controlling the qualified exhaust gas indicators. The absorption liquid is stored in a storage tank and is pressurized by a pump and sent to the atomizing device for atomization. The atomized absorption liquid and flue gas are evenly mixed to absorb the pollutants. The absorption liquid that absorbs pollutants enters the wet electric demister with the flue gas for defogger, and the collected liquid is collected through a pipeline and enters the front-end absorption tower for further recycling. It can effectively solve the problem that the pollutants in the flue gas exceed the standard and are difficult to control in a short time, ensure the production capacity of its production system, and ensure the production efficiency of the enterprise.

[0028] Embodiment 2 like Figure 3 As shown, it is a flue gas treatment device of a copper smelting production enterprise. After the smelting flue gas passes through the bag filter 61 for dust removal, it is powered by the fan 51 to enter the washing tower 41 for washing and dust removal, and then enters the absorption tower 2 to absorb sulfur dioxide with the absorption liquid (the reduction absorption liquid can combine with hydrogen ions in water at low temperature to release hydroxide ions from water, and then the hydroxide ions combine with sulfur dioxide to achieve the effect of absorbing sulfur dioxide. The aforementioned low temperature generally refers to 10°C to 50°C). The absorption liquid that has absorbed sulfur dioxide is pumped into the analysis tower 31 for analysis to release sulfur dioxide gas (the reduction absorption liquid releases hydrogen ions under high temperature conditions). , hydrogen ions combine with hydroxide ions to release sulfur dioxide gas, and the gas released from sulfur dioxide is sent to the acid-making system for acid production, thereby achieving the effect of acid production. The aforementioned high temperature generally refers to 100℃~135℃); the flue gas after dust removal, demisting, and sulfur dioxide removal is further dedused by the electrostatic precipitator 8 after further electric mist removal before reaching the emission standard; when the online monitoring system 9 detects that the sulfur dioxide fluctuation index exceeds 50mg / m³, the atomizer 6 is started, and a high-concentration liquid alkali in an atomized state is quickly sprayed into the flue to instantly absorb the residual sulfur dioxide gas, so that the sulfur dioxide value decreases and reaches a controllable range. In the specific implementation process, it was found that the exhaust sulfur dioxide emission can be controlled within 10 minutes to meet the requirements.

[0029] Embodiment 3 like Figure 4As shown, it is a flue gas treatment device of a copper smelting production enterprise. The flue gas of the anode furnace first enters the high scrubber 57 for cooling and dust removal through the power wave, then enters the packing tower 56 for further cooling and dust removal, and then enters the electrostatic precipitator 82 for electric mist dust removal and mist removal, and then enters the absorption tower 2 to absorb sulfur dioxide (in this process, the absorption liquid that has absorbed sulfur dioxide can be injected into the analysis tower 31 for analysis to release sulfur dioxide gas, and then reused). The flue gas that has absorbed sulfur dioxide is mixed with ozone before entering the fan 52 (through the ozone pipeline 5 5) oxidizes nitrogen oxides in the flue gas, and then sends it to the hydrogen peroxide desulfurization tower 53 to further absorb the residual sulfur dioxide gas in the flue gas, and then enters the liquid alkali spray tower 54 for denitrification, and finally enters the electrostatic precipitator 81 for electrostatic dust removal and demisting before being sent to the chimney for discharge; when the exhaust sulfur dioxide or nitrogen oxide monitoring fluctuates, the atomizer 6 is started, and atomized high-concentration liquid alkali is quickly sprayed into the flue to instantly absorb the residual sulfur dioxide or nitrogen oxide gas, so that the sulfur dioxide or nitrogen oxide value decreases to a controllable range.

[0030] The above embodiments do not impose any formal limitations on the shape, material, structure, etc. of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are within the protection scope of the technical solution of the present invention.

[0031] In the description of the present invention, it is necessary to understand that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the protection content of the present invention.

[0032] If the words "first", "second", etc. are used in this document to limit components, those skilled in the art should know that the use of "first" and "second" is only to facilitate the description of the present invention and simplify the description. Unless otherwise stated, the above words have no special meaning.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A non-ferrous smelting flue gas ultra-low emission device, comprising a flue gas duct, characterized in that: The flue gas duct passes through the absorption tower and the electrostatic precipitator in sequence along the emission direction of the flue gas, then enters the chimney and discharges the flue gas through the chimney. A first purification device is arranged in the absorption tower. A second purification device and an online monitoring system are also arranged in the flue gas duct. The online monitoring system is located between the electrostatic precipitator and the chimney. The online monitoring system is connected to a controller for controlling the start and stop of the second purification device.

2. The ultra-low emission device for non-ferrous smelting flue gas according to claim 1 is characterized in that: The first purification device is a first spray pipe located in the absorption tower. The first spray pipe is connected to one end of a first liquid inlet pipeline, and the other end of the first liquid inlet pipeline is connected to the bottom of the absorption tower. A circulating pump is arranged on the first liquid inlet pipeline.

3. The ultra-low emission device for non-ferrous smelting flue gas according to claim 1 is characterized in that: The second purification device is located between the absorption tower and the electrostatic precipitator.

4. The ultra-low emission device for non-ferrous smelting flue gas according to claim 3 is characterized in that: The second purification device is one or more atomizers arranged in parallel, the atomizers are connected to the air inlet pipeline and the discharge end of the second liquid inlet pipeline, the feed end of the air inlet pipeline is connected to the air storage tank, a valve is provided on the air inlet pipeline, the feed end of the second liquid inlet pipeline is connected to the absorption liquid storage tank, and an absorption liquid spray pump is provided on the second liquid inlet pipeline.

5. The ultra-low emission device for non-ferrous smelting flue gas according to claim 4 is characterized in that: The atomizer is connected to a feed pipeline, and the outlets of the air inlet pipeline and the second liquid inlet pipeline are both connected to the atomizer through the feed pipeline.

6. The ultra-low emission device for non-ferrous smelting flue gas according to claim 1 is characterized in that: A first recovery pipeline connected to the absorption tower is arranged at the bottom of the electrostatic precipitator.

7. The ultra-low emission device for non-ferrous smelting flue gas according to claim 1 is characterized in that: It also includes an analysis tower, wherein a second recovery pipeline is arranged between the analysis tower and the circulation pump, and the second recovery pipeline is connected to a second spray pipe located inside the analysis tower.

8. The ultra-low emission device for non-ferrous smelting flue gas according to claim 7, characterized in that: A third liquid inlet pipeline is also provided between the bottom of the analysis tower and the absorption tower. The third liquid inlet pipeline is connected to a third spray pipe located in the absorption tower. A recovery pump is provided on the third liquid inlet pipeline.

Images