Dioxin control device for grate furnace of garbage power plant

Abstract

The utility model discloses a dioxin control device for a grate furnace of a garbage power plant, relates to the technical field of dioxin treatment and emission reduction, and provides a new technical approach for dioxin emission reduction of the garbage power plant. Comprising a machine frame, a material bin arranged on the machine frame, a material guide pipe arranged in the machine frame and connected with a material outlet of the material bin, and a bin cover arranged on the material bin. The spiral conveyor is vertically and rotatably arranged in the stock bin, and the spiral conveyor comprises a rotating rod and a group of spiral blades arranged on the rotating rod; a blower; in the incineration process, the control device is used for spraying a dioxin inhibitor into the grate furnace through the secondary air pipeline to restrain generation of dioxin, meanwhile, in the tail gas treatment stage, the control device is used for spraying a dioxin adsorbent in front of a cloth bag to adsorb dioxin, and therefore the emission amount of dioxin is controlled.

Description

Technical Field

[0001] The utility model belongs to the technical field of dioxin treatment and emission reduction, and in particular relates to a dioxin control device for a grate furnace in a garbage power plant. Background Art

[0002] Dioxins are a class of colorless, odorless, highly toxic, fat-soluble substances. Dioxins do not refer to a single substance, but to two major categories of organic compounds with similar structures and properties that include many homologues or isomers. More than 90% of dioxin emissions in the atmospheric environment come from incineration. Dioxins are known as the problem of the century, and a large proportion of incineration companies around the world have dioxin levels exceeding the standard.

[0003] At present, for dioxins produced during the incineration process of garbage power plants, the existing technology usually controls the combustion parameters during the incineration stage, including the temperature at any point in the furnace (secondary combustion chamber) is not less than 850℃; the residence time is not less than 2.0S; maintaining sufficient gas-solid turbulence; and excessive air volume, so that the concentration of O2 in the flue gas is between 6% and 11%, that is, the "3T+1E" technology is used to decompose dioxins, and then rapid cooling is used to prevent dioxins from being synthesized again. The activated carbon at the back end adsorbs solid and gaseous dioxins, and finally the activated carbon is intercepted by the bag to achieve the effect of controlling dioxins. When the existing technology cannot guarantee that dioxins meet the emission standards, we designed a dioxin control device for the grate furnace of a garbage power plant, which provides a new supplementary means for dioxin control and emission reduction. Utility Model Content

[0004] The utility model aims to provide a new supplementary means based on the existing dioxin control technology. To this end, the utility model proposes a dioxin control device for a grate furnace in a garbage power plant, which provides a new technical means to ensure that dioxin emissions meet the standards when the existing "3T+1E", rapid cooling and activated carbon bag technologies cannot ensure that dioxin emissions meet the standards.

[0005] To achieve the above-mentioned purpose, according to the embodiment of the first aspect of the utility model, a dioxin control device for a grate furnace in a garbage power plant is provided, comprising a frame, a silo arranged on the frame, a material guide pipe arranged in the frame and connected to a material outlet of the silo, and a silo cover arranged on the silo;

[0006] Also includes:

[0007] A screw conveyor is vertically rotatably arranged in the silo, and the screw conveyor comprises a rotating rod and a group of spiral blades arranged on the rotating rod;

[0008] The blower is arranged at one end of the material guide pipe. An electric control valve is connected to the output pipeline of the blower. The other side of the electric control valve is connected to the material guide pipe. The other end of the material guide pipe is connected to a corrugated feeding pipe.

[0009] A further improvement is that the upper end surface of the material guide pipe is provided with a material inlet, the material bin outlet is inserted into the material inlet, and the outside is connected to the material guide pipe by a plurality of fixing bolts.

[0010] A further improvement is that the screw conveyor is driven by a servo motor externally arranged on the bin cover, and the main shaft of the servo motor is connected to the rotating rod.

[0011] A further improvement is that the device also includes a control box, in which a PLC controller is arranged, and the electric control valve, servo motor and blower are all connected to the PLC controller.

[0012] A further improvement is that the control box is also provided with a power module, a timing switch and an alarm flashing light connected to the PLC controller.

[0013] Compared with the prior art, the beneficial effects of the utility model are:

[0014] (1) The utility model suppresses the generation of dioxins by using the control device to spray the dioxin inhibitor into the grate furnace through the secondary air duct during the incineration process. At the same time, in the exhaust gas treatment stage, the control device is used to spray the dioxin adsorbent from the front of the bag to adsorb the dioxins, thereby controlling the emission of dioxins;

[0015] (2) The utility model can allow inhibitors and adsorbents to be added at regular intervals through a timing switch, and the servo motor drives the screw conveyor to rotate, so that the powder material can be prevented from being blocked under the action of the spiral blades, thereby effectively ensuring that the addition process is carried out continuously and normally, meeting the design requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0017] Figure 2 This is a connection block diagram illustrating the principle of the utility model;

[0018] Figure 3 It is a schematic diagram for explaining the process flow of the utility model.

[0019] Markings in the figure:

[0020] 1. Material guide pipe; 11. Material inlet; 11. PLC control module; 2. Corrugated feed pipe; 3. Rack; 4. Silo; 41. Screw conveyor; 411. Rotating rod; 412. Screw blade; 5. Blower; 51. Electric control valve; 6. Control box; 61. PLC controller; 62. Power module; 63. Timer switch; 64. Alarm flashing light. DETAILED DESCRIPTION

[0021] The technical solution of the utility model will be described clearly and completely in conjunction with the embodiments below. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] like Figure 1 As shown, a grate furnace dioxin control device for a garbage power plant comprises a frame 3, a silo 4 arranged on the frame 3, a material guide pipe 1 arranged in the frame 3 and connected to a material outlet of the silo 4, and a silo cover 42 arranged on the silo 4;

[0023] like Figure 1 As shown, when implemented, it also includes: a screw conveyor 41, which is vertically rotatable and arranged in the silo 4, and the screw conveyor 41 includes a rotating rod 411 and a group of spiral blades 412 arranged on the rotating rod 411;

[0024] The blower 5 is arranged at one end of the material guide pipe 1. An electric control valve 51 is connected to the output pipeline of the blower 5. The other side of the electric control valve 51 is connected to the material guide pipe 1. The other end of the material guide pipe 1 is connected to the corrugated feeding pipe 2.

[0025] The upper end surface of the material guide pipe 1 is provided with a material inlet 11, and the material outlet of the silo 4 is inserted into the material inlet 11, and the outside is connected to the material guide pipe 1 through a plurality of fixing bolts.

[0026] Combination Figure 2 As shown, in this embodiment, the device also includes a control box 6, in which a PLC controller 61 is arranged, and the electric control valve 51, the servo motor 43 and the blower 5 are all connected to the PLC controller. The control box 6 is also provided with a power module 62, a timing switch 63 and an alarm flashing light 64 connected to the PLC controller 61 to supply power to the PLC control module 61. The alarm flashing light 64 is arranged in the control room for convenient prompting.

[0027] Combination Figures 1 to 3As shown, it should be noted that the above-mentioned circuit connection in the application document is the prior art, and there are multiple groups of connection methods, which are not limited in the application document. Each module is a commercially available product and can be used directly. The working principle of the circuit connection has been disclosed, and the application document only makes a block diagram to illustrate the principle; before the implementation of this application, the screw conveyor 41 is driven by a servo motor 43 externally mounted on the bin cover 42, and the main shaft of the servo motor 43 is connected to the rotating rod 411.

[0028] In addition, it is necessary to explain that the dioxin inhibitor in the application document is: 200 mesh powder; the injection location is: grate furnace secondary air duct;

[0029] Among them, the main inhibition principles of dioxin inhibitors can be summarized as follows:

[0030] a. Reduce the amount of dioxins generated by consuming chlorine sources (Cl2, HCl) or changing the form of chlorine sources.

[0031] b. React with metal catalysts and passivate the catalytic effect, thereby reducing the catalytic efficiency of metal catalysts for dioxin formation. This mechanism is considered to be the main working principle of sulfur- or nitrogen-containing inhibitors. Sulfur-containing compounds can convert metal chlorides into sulfates (oxidation conditions) or sulfides (reduction conditions), deactivating metal catalysts; while nitrogen-containing compounds react with metal catalysts in a complex manner to form strongly bonded organic metal nitride complexes, resulting in irreversible deactivation of catalytic sites.

[0032] c. React with dioxin precursors to hinder the precursors from reacting to form dioxins.

[0033] d. Change the pH value of the fly ash surface. For example, nitrogen-containing compounds can reduce the number of acid catalytic sites on the fly ash surface, thereby inhibiting the formation of dioxins.

[0034] The adsorbent injection position in the application document is: connected to the pipeline between the activated carbon and the bag before the bag dust removal. The adsorbent is 200 mesh powder, which is gasified and mixed after injection to adsorb dioxins.

[0035] Among them, the working principle of the adsorbent is as follows:

[0036] The method of removing dioxins is generally to spray the adsorbent into the flue, and the dioxins come into contact with the adsorbent and are then adsorbed and removed. According to the principle of jet adsorption, the contact time between dioxins and the adsorbent is short, and the effective utilization rate of the dioxin adsorbent is low (<3%). Therefore, the key factor for dioxin adsorption is whether the dioxins can quickly enter the adsorbent pores, that is, the diffusion resistance of dioxins entering the pores is the main factor affecting the dioxin adsorption performance, and the diffusion resistance is mainly related to the pore size distribution and pore volume of the adsorbent.

[0037] Among them, the molecular size of dioxin and its homologues is generally 1.3-1.4nm in long axis, about 0.74nm in short axis, and about 0.35nm in thickness. They are relatively large molecules, and their adsorption requires the adsorbent to have larger pores. A large number of literature research results show that the average pore size of the adsorbent used for adsorbing dioxins in flue gas is 2-5nm; when the pore volume is greater than 0.2cm3 / g, the adsorbent has a better effect in adsorbing dioxins;

[0038] The working principle of the dioxin control device of the grate furnace of a garbage power plant is introduced as follows:

[0039] During the incineration process: the servo motor 43 drives the screw conveyor 41 to rotate, so that the powder material falls into the guide pipe 1 under the action of the spiral blade 412. At this time, the spiral blade 412 can prevent the powder material from being blocked. Therefore, by opening the electric control valve 51, the blower 5 sprays the dioxin inhibitor from the guide pipe 1 and the corrugated conveying pipe 2 into the grate furnace, effectively inhibiting the generation of dioxins from the source;

[0040] Tail gas treatment stage: Repeat the above operation to spray the dioxin adsorbent evenly into the pipe before the bag, so that the dioxin emission can meet the standard, which is simple and more effective;

[0041] During use, the inhibitor and the adsorbent can be added regularly through the timing switch 63, with a high degree of automation, which can effectively ensure that the addition process is carried out continuously and normally, meeting the design requirements.

[0042] The above embodiments are only used to illustrate the technical method of the utility model rather than to limit it. Although the utility model is described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical method of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the utility model.

Claims

1. A grate furnace dioxin control device for a garbage power plant, comprising a frame (3), a silo (4) arranged on the frame (3), a material guide pipe (1) arranged in the frame (3) and connected to a material outlet of the silo (4), and a silo cover (42) arranged on the silo (4); It is characterized in that Also includes: A screw conveyor (41) is vertically rotatably disposed in the silo (4), wherein the screw conveyor (41) comprises a rotating rod (411) and a group of spiral blades (412) disposed on the rotating rod (411); The blower (5) is arranged at one end of the material guide pipe (1); an electric control valve (51) is connected to the output pipeline of the blower (5); the other side of the electric control valve (51) is connected to the material guide pipe (1); and the other end of the material guide pipe (1) is connected to the corrugated feed pipe (2).

2. A grate furnace dioxin control device for a garbage power plant according to claim 1, characterized in that: The upper end surface of the material guide pipe (1) is provided with a material inlet (11), the material outlet of the silo (4) is inserted into the material inlet (11), and the outside is connected to the material guide pipe (1) via a plurality of fixing bolts.

3. A grate furnace dioxin control device for a garbage power plant according to claim 1, characterized in that: The screw conveyor (41) is driven by a servo motor (43) externally arranged on the bin cover (42), and the main shaft of the servo motor (43) is connected to the rotating rod (411).

4. A grate furnace dioxin control device for a garbage power plant according to claim 3, characterized in that: The device further comprises a control box (6), wherein a PLC controller (61) is arranged in the control box (6), and the electric control valve (51), the servo motor (43) and the blower (5) are all connected to the PLC controller.

5. A grate furnace dioxin control device for a garbage power plant according to claim 4, characterized in that: The control box (6) is also provided with a power module (62) connected to the PLC controller (61), a time switch (63) and an alarm flashing light (64).

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