Fly ash recycling system for hazardous waste incineration dry deacidification

Abstract

A fly ash recycling system for hazardous waste incineration dry-process deacidification comprises a Venturi reactor, a bag type dust collector, a dust collector screw conveyor, a recycling hopper, an ash discharging valve and recycling conveying equipment.The fly ash recycling system has the advantages that unreacted deacidification agents and dust which are directly discharged by the original bag type dust collector are collected through recycling materials by the aid of equipment transformation design; the fly ash recycling flow is controlled by a variable frequency control ash discharging valve, and then the fly ash is sent back to a throat of the Venturi reactor to be mixed with flue gas again, so that under the condition that the amount of the deacidification agent powder in the Venturi reaction tower is kept consistent, the dosage of the deacidification agent powder in a dry deacidification system of a hazardous waste incineration project is reduced, and the deacidification efficiency is improved. And the amount of the deacidification agent powder newly fed into the Venturi reaction tower can be greatly reduced, so that the dosage of the dry-method deacidification system is saved, and the waste is reduced. Moreover, when the amount of fly ash generated by the combustion system is small, such as a dry deacidification system of a waste liquid incinerator system, the deacidification efficiency can be improved by increasing the circulation ratio of the system.

Description

Technical Field

[0001] The invention relates to the technical field of hazardous waste incineration flue gas treatment, and in particular to a fly ash recycling system for dry deacidification of hazardous waste incineration. Background Art

[0002] The exhaust gas from the incineration of industrial hazardous waste contains a large amount of acidic substances such as SO2, SO3, HCl, etc. In the exhaust gas treatment facilities downstream of the incinerator, a dry deacidification + wet deacidification system is generally set up to remove the acidic substances in the incineration exhaust gas and reduce the environmental pollution caused by the exhaust gas to the atmosphere.

[0003] The dry deacidification system includes a deacidification agent powder injection device, a Venturi reactor, a bag dust collector and an ash discharge device.

[0004] The problem with the existing technology is that the flue gas volume of the hazardous waste incineration system is small, and the corresponding dry deacidification equipment is also small. The capacity of the Venturi reactor used in hazardous waste incineration is much smaller than that of semi-dry reaction equipment in other industries (such as semi-dry rotary atomization deacidification tower in garbage incineration and semi-dry circulating fluidized bed deacidification tower in the steel industry), resulting in limited dry deacidification efficiency for hazardous waste incineration. Low efficiency will cause a large amount of unreacted deacidification agent powder to be discharged with the dust through the dust collector, resulting in waste of deacidification agent.

[0005] Therefore, it is necessary to improve the design of dry deacidification equipment for hazardous waste incineration systems to improve the deacidification efficiency. Through improved results, the deacidification agent powder can react fully to avoid waste. Summary of the invention

[0006] In order to solve the deficiencies of the above-mentioned technologies, the present invention provides a fly ash recycling system for dry deacidification of hazardous waste incineration. The technical solution of the present invention is as follows: A fly ash recycling system for dry deacidification of hazardous waste incineration, comprising a venturi reactor, a bag dust collector, a dust collector screw conveyor, a recycling hopper, an ash discharge valve, a recycling pipeline, and a recycling conveying device. The venturi reactor comprises a flue gas inlet, a flue gas throat, and a flue gas outlet, the flue gas outlet being connected to the bag dust collector, the dust collector screw conveyor being provided with a plurality of ash inlets, a first ash outlet, and a second ash outlet connected to the bag dust collector ash hopper. Ash port, the recycling hopper is provided with a hopper chamber, and a feed port, a discharge port and a circulation outlet connected to the hopper chamber, the feed port is connected to the first ash outlet, the circulation outlet guides the mixed unreacted deacidifying agent and dust into the ash discharge valve, the discharge side of the ash discharge valve is connected to the recycling conveying equipment, the recycling conveying equipment is connected to the flue gas throat of the Venturi reactor, and the ash discharge valve is provided with a frequency conversion controller to control the flow rate of mixed dust introduced into the flue gas throat through the recycling conveying equipment.

[0007] By adopting the above technical scheme, the tail gas containing acidic substances from the incinerator enters the Venturi reactor through the flue gas inlet at the bottom of the Venturi reactor, flows through the throat of the Venturi to be fully mixed with the deacidifying agent powder from the deacidifying agent powder injection device, and then enters the bag filter through the flue outlet at the upper part of the Venturi reactor. In the specific fourteen, the flue of the Venturi reactor is extended as much as possible to ensure the residence time of the deacidifying agent powder in the flue gas to complete the deacidification reaction.

[0008] However, in the case that the Venturi reactor used for hazardous waste incineration is relatively small, the extended setting will still objectively contain unreacted deacidifier powder, which will be discharged along with the dust carried in the flue gas, captured by the bags in the bag collector and evenly hung in the bags. When the flue gas flows through the bags, it will further react with the acidic substances in the flue gas, thereby increasing the residence time.

[0009] The unreacted deacidifying agent powder and dust in the bag will be blown off by the bag backblowing system regularly and enter the fly ash recycling system added to the dry deacidification in this application: that is, the unreacted deacidifying agent and dust concentrated by the dust collector screw conveyor are sent to the recycling hopper, and the flow rate of fly ash recycling is controlled by the ash discharge valve controlled by the frequency conversion under the hopper, and then sent back to the throat of the Venturi reactor through the recycling conveying equipment to be mixed with the flue gas again.

[0010] The excess fly ash is discharged through the spiral outlet arranged in the upper part of the recycling hopper. While keeping the amount of deacidifying agent powder in the venturi reaction tower consistent, the amount of deacidifying agent powder newly added to the venturi reaction tower can be greatly reduced, thereby saving the dosage of the dry deacidification system and reducing waste.

[0011] The utility model is further configured as follows: a first screw conveyor is arranged between the residual discharge outlets of the hopper chamber of the recycling hopper.

[0012] The utility model is further configured as follows: the recycling conveying device comprises a second screw conveyor, one end of which is connected at the feeding side with the discharging side of the ash discharge valve, and the other end is connected to the flue gas throat of the Venturi reactor.

[0013] The utility model is further configured as follows: the recycling and conveying equipment includes a recycling pipeline and a recycling pneumatic conveying fan. The recycling pipeline is connected to the discharge side of the ash discharge valve and the recycling pneumatic conveying fan, and extends to the flue gas throat of the Venturi reactor. The recycling pneumatic conveying fan drives the mixed dust discharged from the ash discharge valve into the flue gas throat.

[0014] A further configuration of the utility model is that a weighing screw conveyor is connected and arranged between the ash discharge valve and the recirculation channel.

[0015] A further configuration of the utility model is that the second screw conveyor is equipped with a screw weighing system.

[0016] With the above technical solution, the recycling conveying equipment can adopt two specific embodiments: pneumatic conveying solution or screw conveying solution. The pneumatic conveying solution is relatively more expensive and can be used with a screw conveyor according to actual working conditions. Setting a weighing screw conveyor to control the recycling amount can more accurately control the return amount.

[0017] Screw conveyors and weighing screw conveyors are both existing technologies, mainly composed of a steady-flow feed screw, a weighing bridge, a reduction motor, a weighing sensor, a speed sensor, a weighing control instrument and an electronic control system. The screw shaft drives the screw blades to rotate, and the solid bulk material is continuously and evenly conveyed to the weighing bridge. The weighing bridge is a lever-type, and its lever fulcrum adopts a trunnion, which is not easily affected by corrosion and external factors on the measurement accuracy. The weight of the material is detected on the weighing bridge. At the same time, the speed sensor installed on the non-driving end of the screw body will perform speed detection. The detected weight signal and speed signal are sent to the weighing controller together for calculus processing, and then the instantaneous flow rate in tons per hour and the cumulative amount in tons are displayed.

[0018] Therefore, the drawings and structures will not be repeated.

[0019] The beneficial effects of the utility model are as follows: the present application, through equipment modification design, collects the unreacted deacidifying agent and dust originally discharged directly from the bag filter through the recycling material, controls the flow rate of fly ash recycling by the frequency conversion-controlled ash discharge valve, and then sends it back to the throat of the venturi reactor to be remixed with the flue gas. While maintaining the amount of deacidifying agent powder in the venturi reaction tower consistent, the amount of deacidifying agent powder added to the dry deacidification system of the hazardous waste incineration project is reduced, which can greatly reduce the amount of deacidifying agent powder newly added to the venturi reaction tower, thereby saving the amount of dosing of the dry deacidification system and reducing waste.

[0020] Moreover, when the amount of fly ash generated by the combustion system is small, such as the dry deacidification system of the waste liquid incinerator system, the deacidification efficiency can be improved by increasing the system circulation rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The structure of the embodiment of the present invention Figure 1 ;

[0022] Figure 2 The structure of the embodiment of the present invention Figure 2 ;

[0023] Among them, 1-Venturi reactor, 11-flue gas throat, 2-bag dust collector, 3-dust collector screw conveyor, 4-recirculation hopper, 41-hopper chamber, 42-feed port, 43-discharge port, 44-circulation port, 45-first screw conveyor, 5-ash discharge valve, 6-second screw conveyor, 7-recirculation pipeline, 8-recirculation pneumatic conveying fan, 9-weighing screw conveyor.

[0024] 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. In addition, the drawings are only used for illustrative purposes and cannot be understood as limitations on this patent. DETAILED DESCRIPTION

[0025] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be further described in detail in detail and in detail in conjunction with the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design. In the absence of conflict, the embodiments in the present application and the technical features in the embodiments can be combined with each other to obtain new embodiments.

[0026] like Figure 1-2 As shown, a fly ash recycling system for dry deacidification of hazardous waste incineration includes a venturi reactor 1, a bag filter 2, a dust collector screw conveyor 3, a recycling hopper 4, an ash discharge valve 5, and a recycling conveying device. The venturi reactor 1 includes a flue gas inlet, a flue gas throat 11, and a flue gas outlet, and the flue gas outlet is connected to the bag filter 2. The dust collector screw conveyor 3 is provided with a plurality of ash inlets, a first ash outlet, and a second ash outlet 31 connected to the ash hopper of the bag filter 2. The recycling hopper 4 is provided with a hopper cavity The hopper chamber 41 comprises a feed port 42, a discharge port 43 and a circulation port 44 which are connected to the hopper chamber 41. The feed port 42 is connected to the first ash outlet. The circulation port 44 guides the mixed unreacted deacidifying agent and dust into the ash discharge valve 5. The discharge side of the ash discharge valve 5 is connected to the recycling conveying equipment. The recycling conveying equipment is connected to the flue gas throat 11 of the Venturi reactor 1. The ash discharge valve 5 is provided with a frequency conversion controller (SIC logo in the drawings of the specification) to control the flow rate of mixed dust introduced into the flue gas throat 11 through the recycling conveying equipment.

[0027] The tail gas containing acidic substances from the incinerator enters the Venturi reactor 1 through the flue gas inlet at the bottom of the Venturi reactor 1, flows through the Venturi throat to be fully mixed with the deacidifying agent powder from the deacidifying agent powder injection device, and then enters the bag filter 2 through the upper flue outlet of the Venturi reactor 1. In the specific embodiment, the flue of the Venturi reactor 1 is extended as much as possible to ensure the residence time of the deacidifying agent powder in the flue gas to complete the deacidification reaction.

[0028] However, when the Venturi reactor 1 used for hazardous waste incineration is relatively small, the unreacted deacidifying agent powder will still exist objectively after the extended setting, and will be discharged along with the dust carried in the flue gas, captured by the bag in the bag filter 2 and evenly hung in the bag. When the flue gas flows through the bag, it will further react with the acidic substances in the flue gas, thereby achieving the purpose of increasing the residence time.

[0029] The unreacted deacidifying agent powder and dust in the bag will be blown off by the bag backblowing system regularly and enter the fly ash recycling system added to the dry deacidification in this application: that is, the unreacted deacidifying agent and dust concentrated by the dust collector screw conveyor 3 are sent to the recycling hopper 4, and the flow rate of fly ash recycling is controlled by the ash discharge valve 5 controlled by the frequency conversion under the hopper, and then sent back to the throat of the Venturi reactor 1 through the recycling conveying equipment to be mixed with the flue gas again.

[0030] The excess fly ash is spirally discharged through the discharge port 43 arranged in the upper middle part of the recycling hopper 4. While maintaining the same amount of deacidifying agent powder in the venturi reaction tower, the amount of deacidifying agent powder newly added to the venturi reaction tower can be greatly reduced, thereby saving the dosage of the dry deacidification system and reducing waste.

[0031] A first screw conveyor 45 is provided between the hopper chamber 41 and the discharge port 43 of the recycling hopper 4 .

[0032] The recycling conveying equipment includes a second screw conveyor 6, one end of which is connected to the discharge side of the ash discharge valve 5, and the other end is connected to the flue gas throat 11 of the Venturi reactor 1. (The M symbol in the circle in the figure of the specification is an electrically driven screw conveyor)

[0033] The recycling and conveying equipment includes a recycling pipeline 7 and a recycling pneumatic conveying fan 8. The recycling pipeline 7 is connected to the discharge side of the ash discharge valve 5 and the recycling pneumatic conveying fan 8, and extends to the flue gas throat 11 of the Venturi reactor 1. The recycling pneumatic conveying fan 8 drives the mixed dust discharged from the ash discharge valve 5 into the flue gas throat 11.

[0034] A weighing screw conveyor 9 is connected between the ash discharge valve 5 and the recirculation channel.

[0035] The second screw conveyor 6 is equipped with a screw weighing system.

[0036] The recycling conveying equipment can adopt two specific embodiments: pneumatic conveying scheme or screw conveying scheme. The pneumatic conveying scheme is relatively more expensive and can be used with a screw conveyor according to actual working conditions. Setting a weighing screw conveyor 9 to control the recycling amount can more accurately control the return amount.

[0037] The screw conveyor and weighing screw conveyor 9 are both existing technologies, and are mainly composed of a steady-flow feeding screw, a weighing bridge, a reduction motor, a weighing sensor, a speed sensor, a weighing control instrument and an electronic control system. The screw shaft drives the screw blades to rotate, and the solid bulk material is continuously and evenly conveyed to the weighing bridge. The weighing bridge is a lever type, and its lever fulcrum adopts an ear shaft, which is not easily affected by corrosion and external factors on the measurement accuracy. The weight of the material is detected on the weighing bridge. At the same time, the speed sensor installed on the non-driving end of the screw body will perform speed detection. The detected weight signal and speed signal are sent to the weighing controller together for calculus processing, and then the instantaneous flow rate in tons per hour and the cumulative amount in tons are displayed.

[0038] Therefore, the drawings and structures will not be repeated.

[0039] The present application adopts equipment modification design to collect the unreacted deacidifying agent and dust originally discharged directly from the bag filter 2 through recycling material, and controls the flow rate of fly ash recycling by the ash discharge valve 5 controlled by frequency conversion, and then sends it back to the throat of the venturi reactor 1 to be mixed with the flue gas again. While maintaining the same amount of deacidifying agent powder in the venturi reaction tower, the amount of deacidifying agent powder added to the dry deacidification system of the hazardous waste incineration project can be reduced, which can greatly reduce the amount of deacidifying agent powder newly added to the venturi reaction tower, thereby saving the amount of dosing of the dry deacidification system and reducing waste.

[0040] Moreover, when the amount of fly ash generated by the combustion system is small, such as the dry deacidification system of the waste liquid incinerator system, the deacidification efficiency can be improved by increasing the system circulation rate.

[0041] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the scope of protection of the present application.

Claims

1. A fly ash recycling system for dry deacidification of hazardous waste incineration, characterized by: It includes a venturi reactor, a bag dust collector, a dust collector screw conveyor, a recycling hopper, an ash discharge valve, and a recycling conveying equipment. The venturi reactor includes a flue gas inlet, a flue gas throat, and a flue gas outlet. The flue gas outlet is connected to the bag dust collector. The dust collector screw conveyor is provided with a plurality of ash inlets, a first ash outlet, and a second ash outlet connected to the ash hopper of the bag dust collector. The recycling hopper is provided with a hopper chamber, and a feed inlet, a discharge outlet, and a circulation outlet connected to the hopper chamber. The feed inlet is connected to the first ash outlet. The circulation outlet guides the mixed unreacted deacidifying agent and dust into the ash discharge valve. The discharge side of the ash discharge valve is connected to the recycling conveying equipment. The recycling conveying equipment is connected to the flue gas throat of the venturi reactor. The ash discharge valve is provided with a frequency conversion controller to control the flow rate of mixed dust introduced into the flue gas throat through the recycling conveying equipment.

2. A fly ash recycling system for dry deacidification of hazardous waste incineration according to claim 1, characterized in that: A first screw conveyor is arranged between the residual discharge outlets of the hopper chamber of the recycling hopper.

3. A fly ash recycling system for dry deacidification of hazardous waste incineration according to claim 2, characterized in that: The recycling conveying equipment comprises a second screw conveyor, one end of which is connected to the discharge side of the ash discharge valve at the feeding side, and the other end of which is connected to the flue gas throat of the Venturi reactor.

4. A fly ash recycling system for dry deacidification of hazardous waste incineration according to claim 2, characterized in that: The recycling and conveying equipment includes a recycling pipeline and a recycling pneumatic conveying fan. The recycling pipeline is connected to the discharge side of the ash discharge valve and the recycling pneumatic conveying fan, and extends to the flue gas throat of the Venturi reactor. The recycling pneumatic conveying fan drives the mixed dust discharged from the ash discharge valve into the flue gas throat.

5. A fly ash recycling system for dry deacidification of hazardous waste incineration according to claim 4, characterized in that: A weighing screw conveyor is connected between the ash discharge valve and the recirculation channel.

6. A fly ash recycling system for dry deacidification of hazardous waste incineration according to claim 3, characterized in that: The second screw conveyor is equipped with a screw weighing system.

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