KR100889597B1 - Division device and mixing device for powdered reagent off-gas treatment of an incineration plant - Google Patents

Abstract

A division and mixing device for powdered reagent off-gas treatment of an incineration plant is provided to improve acid matter within a duct and improve mixing effect with reagent by causing swirl flow of emission using a reagent mixing device. A division and mixing device for powdered reagent off-gas treatment of an incineration plant comprises a drain pipe(100) directing emission generated in the course of burning waste into an emission treating facility; and a reagent supply pipe(200) supplying powdered reagent in order to increase acid gas removal efficiency. A mixing unit evenly mixing the emission and the powdered reagent is installed in the drain pipe. The mixing unit is a spiral blade causing the swirl flow of emission. The spiral blade comprises a first spiral blade(120) installed in a pipe(110) located inside the drain pipe; and a second spiral blade(130) installed between the outer surface of a pipe and an inner surface of the drain pipe.

Description

Mixing device and distribution device of dry reactant for incinerator flue gas treatment {DIVISION DEVICE AND MIXING DEVICE FOR POWDERED REAGENT OFF-GAS TREATMENT OF AN INCINERATION PLANT}

The present invention relates to the treatment of exhaust gas in an incinerator, and more particularly, it is possible to increase the mixing effect of the exhaust gas discharged from the incinerator and the dry reactant sodium bicarbonate (NaHCO ₃ ) and the acid gas removal efficiency contained in the exhaust gas. An apparatus for mixing and distributing a dry reactant for incinerator flue gas treatment.

In general, an incineration method using an incinerator is used as one of waste treatment methods. This method of incineration can reduce the volume and weight of the waste compared to landfill, but there is a difficulty in having a thorough pollution prevention facility because air pollutants are generated.

The incinerator is composed of an incinerator and a pretreatment facility for uniformly supplying waste to the incinerator, a waste heat boiler for recovering heat from the exhaust gas and cooling the exhaust gas, and an exhaust gas treatment facility for removing contaminants in the exhaust gas.

The exhaust gas treatment facility provided in such an incineration treatment apparatus contains acidic substances such as hydrogen chloride (HCl) and sulfur oxides (SOx), dust, heavy metals, nitrogen oxides (NOx), dioxins and the like in the atmosphere. It is a facility to remove before being discharged. It can be classified into three types according to acidic treatment process.

1) wet process

As the exhaust gas from which dust is removed from the electrostatic precipitator is cooled to the saturated state by the circulating water in the wet scrubber, the exhaust gas from the scrubber is cooled to 60-80 ° C, and the exhaust gas flowing into the scrubber is scrubbed. A method of removing acid gas by the sodium hydroxide solution sprayed from the spray nozzle installed in the pump, comprising an electrostatic precipitator, a wet washing tower through which sodium hydroxide is circulated and discharged, a bag filter, a gas heater, and a selective catalytic reduction (SCR) unit. do.

2) semi-dry process

As the calcium hydroxide slurry supplied to the semi-dry reaction tower reacts with the exhaust gas, the liquid phase evaporates, acid gas forms a reaction crystal state, and the solid product is collected by the bag filter, which is a post stage equipment, and discharged. It consists of a semi-dry reaction tower, a bag filter, a gas heater, and a selective catalytic reduction (SCR) unit.

3) dry process

The exhaust gas discharged from the waste heat boiler is cooled in a water spray type heating tower and sprayed with calcium hydroxide in a fine powder form to form a filter cake in the bag filter and react with acidic gas to remove it as neutral salt. It consists of a filter, a gas heater and a selective catalytic reduction (SCR) section.

The wet process, semi-dry process, and the dry process briefly summarized as shown in Table 1 below.

TABLE 1

The treatment process of the exhaust gas is as follows.

Wet process: Electrostatic precipitator → Wet washing tower (sodium hydroxide circulation and discharge) → Steam gas heater → Selective catalyst reduction (SCR)

Semi-dry process: Semi-dry reaction tower (calcium hydroxide slurry) → Activated carbon → Bag filter → Selective catalyst reduction (SCR)

Drying process: temperature tower → calcium hydroxide powder → activated carbon → bag filter → selective catalytic reduction (SCR)

In the wet process, the sodium hydroxide solution is circulated in the wet washing tower to remove acid gas, and the semi-dry process sprays calcium hydroxide slurry into the semi-dry reaction tower to remove acid gas. Remove acid gas.

In the above three processes, the acid gas treatment facility is large, and the temperature of the exhaust gas is lowered from 200 ° C. to 140 to 160 ° C. after the waste heat boiler and heated to 180 to 300 ° C., which is the active temperature of the catalyst in the catalyst tower process. This creates a fuel cost problem.

In particular, when the calcium hydroxide powder is used as a problem of the conventional dry process, the temperature reduction and heating facilities of the exhaust gas are required, and the mixture of the exhaust gas and the reactant is not well achieved, and the exhaust gas introduced into the bag filter is localized. In order to overcome the flow through the filter bag, etc., sodium bicarbonate was used as a reactant, and a reactant mixer and a bag filter distributor were installed.

In addition, the existing dry process uses potassium hydroxide powder as a reactant, and there is no specially designed device for mixing and distributing the bag filter.

The present invention has been made to solve the conventional problems as described above, an object of the present invention to increase the mixing effect of the exhaust gas discharged from the incinerator and sodium bicarbonate dry reactant to increase the acid gas removal efficiency contained in the exhaust gas It is to provide an apparatus for mixing and distributing a dry reactant for incinerator flue gas treatment that can be increased.

The mixing device of the dry reactant for incinerator flue gas treatment proposed by the present invention,

Sodium bicarbonate (NaHCO _{3), which is a} dry reactant for guiding the exhaust gas generated during incineration of waste in the incinerator, to the exhaust gas treatment facility, and to increase the efficiency of removing acid gas contained in the exhaust gas by connecting to the exhaust pipe. And a reactant supply line for supplying

The discharge pipe is provided with a mixing device of the dry reactant for incinerator flue gas treatment provided with a mixing means for allowing the exhaust gas and the reactant to be evenly mixed.

The mixing means is composed of a spiral blade installed inside the discharge pipe to make the discharge gas flowing through the discharge pipe to the swirl flow flow.

The helical blade is composed of a first spiral blade installed inside the pipe located inside the discharge pipe passage, and a second spiral blade installed between the pipe outer surface and the discharge pipe inner surface.

In another aspect, the present invention, the exhaust pipe for guiding the discharge gas generated during the incineration of the waste in the incinerator to the exhaust gas treatment facility, and is connected to the discharge pipe is a dry reactant to increase the acid gas removal efficiency contained in the exhaust gas Reactant supply pipe for supplying sodium bicarbonate (NaHCO ₃ ) and a bag filter for removing the acidic substances contained in the exhaust gas while passing through the exhaust gas mixed with the reactant,

It provides a distribution device for incinerator flue gas treatment incinerator flue gas treatment provided with a distribution means for allowing the reactant to flow evenly over the entire area of the bag filter when the exhaust gas mixed with the reactant passed through the discharge pipe is unique to the bag filter. .

The distribution means includes a frame installed on the inlet side of the bag filter and a diffusion member installed on the frame to diffuse the reactant introduced into the bag filter into the bag filter.

The frame is formed in the shape of a gradient in the direction of the bag filter, the diffusion member is installed in a round shape in the direction of the bag filter, the diffusion member is composed of a plurality of angles having an inclined surface gradually toward the bag filter direction.

The mixing and distribution device of the dry reactant for flue gas treatment of the incinerator according to the present invention generates a swirl flow of the exhaust gas using the reactant mixing device to improve the mixing effect with the reactant and to increase the reaction efficiency. By increasing the mixing effect of the exhaust gas and sodium bicarbonate powder, the removal of acidic substances on the duct can be improved efficiency.

In addition, by uniformly applying the sodium bicarbonate contained in the inlet exhaust gas to the filter bag can be removed more than 90% in the inflow load variation of the acid gas contained in the exhaust gas flowing into the bag filter.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in more detail.

1 and 2 are views illustrating a mixing device of the dry reactant for treating the exhaust gas of the incinerator according to the present invention, Figures 3 to 5 is a distribution device of the dry reactant for treating the exhaust gas of the incinerator according to the present invention. To illustrate the drawing.

The incineration apparatus has an exhaust gas treatment facility for removing and destroying contaminants in exhaust gas (combustion gas) generated by incineration of waste in an incinerator.

The exhaust gas treatment proceeds while the exhaust gas is moved along a predetermined path along an exhaust pipe line 100 such as a duct. At this time, a dry reaction is carried out on the exhaust pipe line 100 through which the exhaust gas discharged through the waste heat boiler (not shown) flows. By adding sodium bicarbonate (NaHCO ₃ ) zein can be configured to remove the acid gas contained in the exhaust gas.

To this end, the exhaust pipe line (100) is connected to a dry reactant supply pipe (200) to supply a dry reactant sodium bicarbonate (NaHCO ₃ ) with air to the exhaust gas flowing through the discharge pipe line (100).

In the dry reactant supply pipe 200, a spiral blade 210 is installed to maintain the flow of swirl flow when sodium bicarbonate is supplied to the discharge pipe 100.

In the present invention, the discharge pipe 100 is provided with a mixing means so that the discharge gas and the dry reactant evenly mixed when the discharge gas passes through the portion of the dry reactant supply pipe 200.

The mixing means is composed of a spiral blade is installed in the discharge pipe line 100 to make the discharge gas flowing through the discharge pipe line 100 into a swirl flow flow.

The spiral blade is installed between the first spiral blade 120 installed inside the pipe 110 located inside the discharge pipe 100 and between the outer surface of the pipe 110 and the inner surface of the discharge pipe 100. It consists of a second spiral blade 130.

The first and second spiral blades 120 and 130 may be formed of one or two or more pieces, respectively, and the discharge gas flowing through the discharge pipe line 100 is rotated due to the spiral blades 120 and 130. The dry reactant introduced through the reactant supply line 200 is then mixed with the exhaust gas by flowing into the flow stream.

The exhaust gas passing through the reactant mixing device flows along the discharge pipe 100 and passes through a bag filter (not shown) to collect acidic substances (hydrogen chloride (HCl), sulfur oxides (SOx), etc.) contained in the exhaust gas. In this case, a distribution means is provided at the inlet 140 of the bag filter, which is an end of the discharge pipe 100, so that the dry reactant supplied with the discharge gas may be uniformly applied to the bag filter.

The distribution means includes a frame 300 installed at the inlet 140 side of the bag filter, and a diffusion member installed at the frame 300 to diffuse the reactants introduced into the bag filter into the bag filter.

The frame 300 is formed in the shape of a gradient in the direction of the bag filter, the diffusion member is installed in a round arrangement in the direction of the bag filter.

The diffusion member is composed of a plurality of angles 310 having an inclined surface that gradually opens toward the bag filter direction.

The frame 300 is fixed to the fixing part 320 extending in a state in which one side is fixed to the discharge pipe 100, the angle 310 is installed in such a frame 300 while maintaining the interval discharge gas is Passing through the angle 310 is to be widely spread outward.

The mixing device and distribution device of the dry reactant for incineration flue gas treatment of the present invention as described above are provided in an incineration treatment device consisting of waste input → incinerator → waste heat boiler → reactant mixing device → bag filter distribution device → bag filter → blower. do.

During the incineration treatment, the exhaust gas flows into the swirl flow by the spiral blades 120 and 130 while passing through the reactant mixing device to the exhaust gas passing through the waste heat boiler, and thus reacts directly through the dry reactant supply pipe 200. When the sodium sodium bicarbonate powder is added, the reaction mixture is well mixed.

And the exhaust gas mixed with the reactant passes through the reactant distribution device and uniformly apply sodium bicarbonate contained in the exhaust gas to the bag filter, so that the sodium bicarbonate reactant forms a cake on the bag filter, so that the residual acidic substance is hydrogen chloride (HCl), Sulfur dioxide (SO ₂ ), sulfur trioxide (SO ₃ ), and hydrogen fluoride (HF) form a cake to remove more than 50% of residual acidic substances. Such a reagent dispensing apparatus can stably remove more than 90% of acidic substances even under fluctuating load of acidic gas. At this time, the reaction of removing the acidic gas in the sodium bicarbonate and the exhaust gas is shown in Scheme 1.

Scheme 1

NaHCO ₃ + HCl → NaCl + H ₂ O + CO

2 NaHCO ₃ + SO ₂ + P O ₂ → Na ₂ SO ₄ + H ₂ O + 2 CO ₂

2 NaHCO ₃ + SO ₃ → Na ₂ SO ₄ + H ₂ O + 2 CO ₂

NaHCO ₃ + HF → NaF + H ₂ O + CO ₂

1 is a view of a state in which a pipeline is cut in order to explain the mixing device of the dry reactant for incinerator flue gas treatment according to the present invention.

2A and 2B are views seen from line A-A and line B-B of FIG.

Figure 3 is a plan view of the distribution device of the dry reactant for incinerator flue gas treatment according to the present invention.

Figure 4 is a front view of the distribution apparatus of the dry reactant for incinerator flue gas treatment according to the present invention.

Figure 5 is a side view of the distribution device for the dry reactant for incinerator flue gas treatment according to the present invention.

Claims (6)

Reactor for guiding the exhaust gas generated during the incineration of waste in the incinerator to the exhaust gas treatment facility, and a reactive agent for supplying a dry reactant to increase the efficiency of removing acid gas contained in the exhaust gas connected to the discharge line Including a supply pipeline, The discharge pipe is provided with a mixing means made to be evenly mixed with the exhaust gas and the dry reactant, The mixing means is composed of a spiral blade which is installed inside the discharge pipe to make the discharge gas flowing through the discharge pipe in a swirl flow flow, the spiral blade is installed in the interior of the pipe located inside the discharge pipe passage and the spiral blade; Mixing apparatus for a dry reactant for incinerator flue gas treatment comprising a second spiral blade installed between the pipe outer surface and the discharge pipe inner surface. delete delete Reactor for guiding the exhaust gas generated during the incineration of waste in the incinerator to the exhaust gas treatment facility, and a reactive agent for supplying a dry reactant to increase the efficiency of removing acid gas contained in the exhaust gas connected to the discharge line A supply filter and a bag filter for removing acidic substances contained in the exhaust gas while the exhaust gas mixed with the reactant passes therethrough, Distributing means is provided so that the reactant can be introduced evenly over the entire area of the bag filter when the discharge gas mixed with the reactant passed through the discharge pipe is introduced into the bag filter, The distribution means has a frame installed on the inlet side of the bag filter and an inclined surface gradually installed toward the bag filter so as to diffuse the reactants introduced and mixed with the exhaust gas into the bag filter while maintaining a space on the frame. Drying agent distribution device for incinerator flue gas treatment consisting of a diffusion member consisting of a plurality of angles. delete The method according to claim 4, The frame is made in the form of a gradient in the direction of the bag filter, the angle is installed in the frame is a distribution device for incinerator flue gas treatment incinerator installed in a round arrangement in the direction of the bag filter.

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