Nozzle, gasifier containing the same, and method for treating wastewater and organic waste liquid

Abstract

The present invention discloses a nozzle and a gasifier containing the same, and a method for treating wastewater and organic waste liquid. The nozzle includes an outer ring nozzle, a middle ring nozzle, an inner ring nozzle, and a center nozzle coaxially arranged from the outside to the inside; an outer ring channel is formed between the inner side wall of the outer ring nozzle and the outer side wall of the middle ring nozzle; a middle ring channel is formed between the inner side wall of the middle ring nozzle and the outer side wall of the inner ring nozzle; an inner ring channel is formed between the inner side wall of the inner ring nozzle and the outer side wall of the center nozzle; and the inner wall of the center nozzle encloses to form a center channel. The nozzle of the present invention can flexibly treat wastewater and organic waste liquid of different flow rates, has good atomization effect, and has no serious ablation, clogging and other problems. It has the advantages of high carbon conversion rate and effective gas component content, low syngas fly ash content, low ash-to-slag ratio, and no secondary pollution, saves steam, and can take into account both efficient gasification of pulverized coal and resource utilization of wastewater and organic waste liquid.

Description

Technical Field

[0001] The invention relates to a pulverized coal gasification nozzle, a gasifier comprising the nozzle, and a method for treating waste water and organic waste liquid. Background Art

[0002] Entrained-flow pulverized coal gasification generally uses an oxidant (air, enriched oxygen, oxygen, steam, etc.) to spray pulverized coal through a nozzle into an entrained-flow gasifier for gasification to produce synthesis gas (CO, H2). It can be used as a raw material for synthetic ammonia, synthetic methanol and synthetic liquid fuels, as well as metallurgical and kiln gas, city gas, etc. It is one of the important processes in coal chemical industry.

[0003] Taking the SE Dongfang furnace's pulverized coal pressurized gasification technology as an example, it uses pure oxygen and pulverized coal as raw materials and has currently reached a single furnace daily processing capacity of 2,000 tons of coal. This technology utilizes a dry pulverized coal pressurized gasification and quenching process. Its core technologies include a single-nozzle water-cooled wall gasifier, a gasification burner, and a process control system. Based on research into the multiphase turbulent reaction flow process within an entrained-flow gasifier and the ash-slag characteristics of high-ash melting point and high-ash content coals, the gasifier's flow field and wall slag flow are controlled to achieve coupling between the high-temperature zone at the gasifier slag outlet and liquid slag discharge, as well as coupling the slag layer thickness distribution with the temperature distribution. This gasifier is suitable for the clean and efficient gasification of low-quality coals with high ash melting point and high ash content, demonstrating advantages such as high carbon conversion (98%), high effective gas content (89%), low syngas fly ash content (<1 mg / Nm³), and a low ash-to-slag ratio (3:7).

[0004] With the advancement of my country's dual carbon and environmental protection strategies, utilizing the reducing atmosphere and high temperature (1400°C) of large-scale pulverized coal gasification technology to efficiently and harmlessly recycle large amounts of wastewater and organic waste liquids can both meet demand and generate revenue for enterprises. Therefore, there is an urgent need for a pulverized coal gasification nozzle capable of treating wastewater and organic waste liquids, and a method for its use. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defect in the prior art that a large amount of wastewater and organic waste liquid cannot be harmlessly resourced and efficiently utilized, and to provide a nozzle and a gasification furnace containing the same, and a method for treating wastewater and organic waste liquid.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] The present invention provides a nozzle for pulverized coal gasification, the nozzle comprising an outer ring nozzle, a middle ring nozzle, an inner ring nozzle and a center nozzle which are coaxially arranged in sequence from the outside to the inside;

[0008] An outer ring channel is formed between the inner side wall of the outer ring nozzle and the outer side wall of the middle ring nozzle; a middle ring channel is formed between the inner side wall of the middle ring nozzle and the outer side wall of the inner ring nozzle; an inner ring channel is formed between the inner side wall of the inner ring nozzle and the outer side wall of the central nozzle; a central channel is formed by enclosing the inner wall of the central nozzle;

[0009] The contraction angle a of the central channel is 0° - 20°, the contraction angle b of the inner ring nozzle is 5° - 30°, the contraction angle c of the middle ring nozzle is 15° - 45°, and the contraction angle d of the outer ring nozzle is 35° - 85°;

[0010] Among them, the contraction angle of each nozzle refers to the angle formed by enclosing the side wall of the nozzle in the axial cross-sectional view.

[0011] Preferably, the contraction angle a of the central channel is 10° - 20°;

[0012] And / or, the contraction angle b of the inner ring nozzle is 5° - 10°;

[0013] And / or, the contraction angle d of the outer ring nozzle is 35° - 65°.

[0014] Preferably, a swirler is arranged inside the outer ring channel.

[0015] Preferably, the swirl number of the swirler is S, where 0 < S ≤ 5; the swirl number reflects the ratio of the tangential velocity to the axial velocity of the fluid at the nozzle outlet.

[0016] Preferably, a water-cooled jacket is arranged on the outer peripheral surface of the outer ring nozzle.

[0017] The present invention also provides a gasifier, and the gasifier is provided with the nozzle as described above.

[0018] The present invention also provides a method for treating wastewater and organic waste liquid. The wastewater and organic waste liquid refer to industrial and domestic wastewater, organic liquid or slurry (particle size not greater than 1 mm) with an apparent viscosity not greater than 1.2 Pa·s. The treatment method uses the gasifier as described above, and the treatment method includes the following steps:

[0019] S1. Introduce combustible gas into the central channel and the outer ring channel, introduce inert gas into the inner ring channel, introduce oxygen into the middle ring channel, and turn on the ignition device to ignite the central channel;

[0020] S2. After ignition is completed, introduce oxygen into the central channel and the middle ring channel, introduce pulverized coal into the inner ring channel, introduce wastewater and organic waste liquid into the outer ring channel, and control the flow rates of oxygen, pulverized coal, and wastewater and organic waste liquid in each channel to generate the required substances.

[0021] Preferably, in the above steps, when the treatment amount of wastewater and organic waste liquid fluctuates greatly, inert gas is mixed into the wastewater and organic waste liquid and introduced into the outer ring channel.

[0022] Preferably, in the above steps, the outlet flow rate of the central channel when spraying is 10-80m / s;

[0023] and / or, the outlet flow velocity of the inner ring channel during spraying is 1-30 m / s;

[0024] and / or, the outlet flow velocity of the middle ring channel during ejection is 50-100 m / s;

[0025] And / or, the outlet flow velocity of the outer ring channel during spraying is 0.5-10m / s.

[0026] Preferably, in the above steps, when switching the injection materials into each channel in steps S1 and S2, it is necessary to ensure that the gasifier is not extinguished.

[0027] On the basis of conforming to the common sense in this field, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0028] The positive progress of the present invention is that the nozzle of the present invention can flexibly process wastewater and organic waste liquids with different flow rates, has good atomization effect, no serious ablation, blockage and other problems, has the advantages of high carbon conversion rate and effective gas component content, low syngas fly ash content, low ash-slag ratio, and no secondary pollution, saves steam, and can take into account both efficient gasification of pulverized coal and resource utilization of wastewater and organic waste liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the cross-sectional structure of the nozzle in a preferred embodiment of the present invention.

[0030] Figure 2 Schematic diagram of the process of treating wastewater and organic waste liquid in a preferred embodiment of the present invention.

[0031] Description of reference numerals:

[0032] Outer ring nozzle 10

[0033] Central sprinkler 20

[0034] Inner ring nozzle 30

[0035] Center nozzle 40

[0036] Center channel 50

[0037] Inner ring channel 60

[0038] Central Channel 70

[0039] Outer ring channel 80

[0040] Cyclone 90 Specific embodiments

[0041] The present invention will be further described below by way of embodiments, but the present invention is not limited to the scope of the following embodiments.

[0042] As Figure 1 As shown, the present invention provides a nozzle for pulverized coal gasification. The nozzle includes an outer ring spray head 10, a middle ring spray head 20, an inner ring spray head 30, and a central spray head 40 which are coaxially arranged from outside to inside in sequence. An outer ring channel 80 is formed between the inner side wall of the outer ring spray head 10 and the outer side wall of the middle ring spray head 20; a middle ring channel 70 is formed between the inner side wall of the middle ring spray head 20 and the outer side wall of the inner ring spray head 30; an inner ring channel 60 is formed between the inner side wall of the inner ring spray head 30 and the outer side wall of the central spray head 40; a central channel 50 is formed by enclosing the inner wall of the central spray head 40. Among them, the contraction angle of each spray head refers to the angle formed by the side walls of each spray head in the axial cross-sectional view; that is, on the longitudinal section where the central axis of the nozzle is located, the angle formed by the intersection of the extension lines of the two opposite inner side walls of each spray head is the contraction angle of the spray head.

[0043] The contraction angle a of the central channel 50 is 0° - 20°, the contraction angle b of the inner ring spray head 30 is 5° - 30°, the contraction angle c of the middle ring spray head 20 is 15° - 45°, and the contraction angle d of the outer ring spray head 10 is 35° - 85°. Preferably, the contraction angles of each channel are within the following ranges: the contraction angle a of the central channel 50 is 10° - 20°; the contraction angle b of the inner ring spray head 30 is 5° - 10°; the contraction angle c of the middle ring spray head 20 is 20° - 40°; the contraction angle d of the outer ring spray head 10 is 35° - 65°.

[0044] A cyclone 90 is arranged inside the outer ring channel 80, and the outer diameter of the cyclone 90 is equal to the inner diameter of the outer ring spray head 10. Among them, the swirl number of the cyclone 90 is S, where 0 < S ≤ 5; the swirl number reflects the ratio of the tangential velocity to the axial velocity of the fluid at the nozzle outlet. By arranging the cyclone 90, the ratio of the tangential velocity to the axial velocity of the fluid at the outlet of the outer ring channel 80 is maintained within a preset range, optimizing and improving the atomization angle of the nozzle, improving the mixing and atomization effect of the nozzle, improving the carbon utilization rate (or conversion rate), and the yield of effective gas (H2 + CO). At the same time, after arranging the cyclone 90, the length of the combustion flame can be effectively shortened, thereby playing a role in protecting the refractory lining of the entrained flow gasifier and extending the life of the furnace.

[0045] A water-cooled jacket is also arranged on the outer peripheral surface of the outer ring spray head 10. By arranging a water-cooled jacket on the outer peripheral surface of the outer ring spray head 10, the nozzle can be cooled by introducing cooling water into the water-cooled jacket, avoiding the excessive temperature of the outside of the nozzle and extending the life of the nozzle.

[0046] The present invention also provides a gasifier using the aforementioned pulverized coal gasification nozzle. The gasifier sprays an oxidant (air, enriched oxygen, oxygen, steam, etc.) and pulverized coal through different channels of the nozzle into the entrained-flow gasifier for gasification to produce synthesis gas (CO, H2). This synthesis gas can be used as a feedstock for synthesizing ammonia, synthesizing methanol, and synthesizing liquid fuels, or as metallurgical and kiln gas, city gas, and the like.

[0047] In specific use, combustible gas (liquefied petroleum gas, natural gas, etc.) is first introduced into the central channel 50, inert gas (nitrogen, CO2, etc.) into the inner annular channel 60, oxygen into the middle annular channel 70, and combustible gas (liquefied petroleum gas, natural gas, etc.) into the outer annular channel 80. The combustible gas in the central channel 50 is then ignited by an igniter. The substances flowing into different channels within the nozzle are then changed, with oxygen introduced into the central channel 50, pulverized coal into the inner annular channel 60, oxygen into the middle annular channel 70, and steam into the outer annular channel 80. This method allows the mixture to be gasified in an entrained flow gasifier to produce synthesis gas.

[0048] like Figure 2 The present invention also provides a method for treating wastewater and organic waste liquid, wherein wastewater and organic waste liquid refer to industrial and domestic wastewater with an apparent viscosity of no more than 1.2 Pa·s, and liquids or slurries containing organic matter (with organic matter particles having a particle size of no more than 1 mm). Wastewater and organic waste liquid can be treated by the above-mentioned gasification furnace.

[0049] The treatment method for wastewater and organic waste liquid includes the following steps:

[0050] S1. Pass combustible gas into the central channel 50 and the outer ring channel 80, pass inert gas into the inner ring channel 60, pass oxygen into the middle ring channel 70, and turn on the ignition device to ignite the central channel 50;

[0051] S2. After ignition is completed, oxygen is introduced into the central channel 50 and the middle ring channel 70, the pulverized coal is introduced into the inner ring channel 60, and the wastewater and organic waste liquid are introduced into the outer ring channel 80. The flow rates of oxygen, pulverized coal, wastewater and organic waste liquid in each channel are controlled to generate the required substances.

[0052] In the above steps, when the wastewater and organic waste liquid treatment volumes fluctuate significantly, an inert gas (a gas that does not chemically react with the waste liquid to cause danger, including nitrogen, CO2, or synthesis gas) is mixed into the wastewater and organic waste liquid and passed into the outer ring channel 80. This is because the nozzles of the gasifier are designed based on a certain waste liquid volume. When the actual waste liquid volume is less than the designed value, mixing the inert gas into the outer ring channel 80 has the following advantages:

[0053] 1. Improve the flexibility of wastewater and organic waste liquid treatment, so that the waste liquid treatment range of the nozzle reaches 0-100% of the design value;

[0054] 2. Protect the nozzle to avoid ablation and safety risks caused by too low liquid volume in the outer ring channel 80;

[0055] 3. Adding inert gas helps to enhance the mixing of materials sprayed from the nozzle.

[0056] When treating wastewater and organic waste liquid, the outlet flow rate of each channel of the nozzle can be set according to the treatment volume of the wastewater and organic waste liquid and the content of each component in the desired synthesis gas. Generally speaking, the outlet flow rate of each channel of the nozzle can be selected within the following numerical range: the outlet flow rate of the central channel 50 when spraying is 10-80m / s; the outlet flow rate of the inner ring channel 60 when spraying is 1-30m / s; the outlet flow rate of the middle ring channel 70 when spraying is 50-100m / s; the outlet flow rate of the outer ring channel 80 when spraying is 0.5-10m / s. The specific settings can be set according to actual conditions, and no examples or limitations are given here.

[0057] When treating wastewater and organic waste, after ignition is complete, the ignition device is allowed to burn for a certain period of time (this period depends on the characteristics of the feedstock, reactor size, and process conditions, and is not limited here). Wait until the gasifier is operating stably before shutting off the ignition device. Furthermore, when switching the injection materials into the various channels in steps S1 and S2, the gasifier must not be shut down.

[0058] It should be noted that when the above nozzles are used to treat wastewater and organic waste liquids, the applicable pressure range of the nozzles is not greater than 20 MPa.

[0059] The following is a series of examples to further illustrate the effect of the pulverized coal gasification nozzle of the present invention on treating wastewater and organic waste liquid.

[0060] Table 1 below shows the structural parameters of the nozzles used for pulverized coal gasification in Examples 1-4:

[0061] Table 1 Structural parameters of the nozzle for pulverized coal gasification

[0062]

[0063] Table 2 below shows the process parameters of the nozzles used for pulverized coal gasification in Examples 1-4:

[0064] Table 2 Process parameters of nozzles for pulverized coal gasification

[0065]

[0066] After the pulverized coal gasification nozzles of the above embodiments were installed in the SE Oriental furnace, wastewater, organic waste liquid, other gases and pulverized coal were introduced into the corresponding channels according to the data of the corresponding embodiments in the above table. The gasification results were carbon conversion rate of about 99%, effective gas content of about 90%, and syngas fly ash content of less than 0.5 mg / Nm 3 , the ash-slag ratio is about 2:8, and it has the advantages of high carbon conversion rate and effective gas component content, low synthesis gas fly ash content, and low ash-slag ratio; and the continuous service life of the pulverized coal gasification nozzle can theoretically reach 2 years, and no additional water vapor is required, which fully meets the requirements of long-term stable and safe operation of coal gasification.

[0067] The nozzle of the present invention can flexibly process wastewater and organic waste liquids with different flow rates, has good atomization effect, no serious ablation, blockage and other problems, high conversion rate, no secondary pollution, saves steam, and can take into account both efficient gasification of pulverized coal and resource utilization of wastewater and organic waste liquid.

[0068] Although specific embodiments of the present invention have been described above, those skilled in the art will appreciate that these are merely illustrative and that the scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, and such changes and modifications are intended to fall within the scope of the present invention.

Claims

1. A method for treating wastewater and organic waste liquid, wherein the wastewater and organic waste liquid refer to industrial and domestic wastewater, liquid containing organic matter or slurry with an apparent viscosity of no more than 1.2 Pa·s and a particle size of no more than 1 mm, characterized in that: The described processing method uses a gasifier, and the gasifier is equipped with a nozzle for pulverized coal gasification; The nozzle includes an outer ring spray head, a middle ring spray head, an inner ring spray head, and a central spray head that are coaxially arranged from outside to inside in sequence; An outer ring channel is formed between the inner side wall of the outer ring spray head and the outer side wall of the middle ring spray head; a middle ring channel is formed between the inner side wall of the middle ring spray head and the outer side wall of the inner ring spray head; an inner ring channel is formed between the inner side wall of the inner ring spray head and the outer side wall of the central spray head; a central channel is enclosed by the inner wall of the central spray head; The contraction angle a of the central channel is 0° - 20°; the contraction angle b of the inner ring spray head is 5° - 30°; the contraction angle c of the middle ring spray head is 15° - 45°; the contraction angle d of the outer ring spray head is 35° - 85°; Among them, the contraction angle of each spray head refers to the angle formed by the side wall of the spray head in the axial sectional view; The described processing method includes the following steps: S1. Introduce combustible gas into the central channel and the outer ring channel, introduce inert gas into the inner ring channel, introduce oxygen into the middle ring channel, and turn on the ignition device to ignite the central channel; S2. After ignition is completed, introduce oxygen into the central channel and the middle ring channel, introduce pulverized coal into the inner ring channel, introduce wastewater and organic waste liquid into the outer ring channel, and control the flow rates of oxygen, pulverized coal, wastewater, and organic waste liquid in each channel to generate the required substances; When the treatment amount of wastewater and organic waste liquid fluctuates greatly, mix inert gas into the wastewater and organic waste liquid and introduce them into the outer ring channel; The outlet flow rate when the central channel sprays out is 10 - 80 m / s, the outlet flow rate when the inner ring channel sprays out is 1 - 30 m / s, the outlet flow rate when the middle ring channel sprays out is 50 - 100 m / s, and the outlet flow rate when the outer ring channel sprays out is 0.5 - 10 m / s.

2. The method for treating wastewater and organic waste liquid according to claim 1, wherein: The contraction angle a of the central channel is 10° - 20°; And / or, the contraction angle b of the inner ring spray head is 5° - 10°; And / or, the contraction angle d of the outer ring spray head is 35° - 65°.

3. The method for treating wastewater and organic waste liquid according to claim 1, wherein: A swirler is arranged inside the outer ring channel.

4. The method for treating wastewater and organic waste liquid according to claim 3, wherein: The swirl number of the swirler is S, where 0 < S ≤ 5; the swirl number reflects the ratio of the tangential velocity to the axial velocity of the fluid at the nozzle outlet.

5. The method for treating wastewater and organic waste liquid according to claim 1, wherein: The outer peripheral surface of the outer ring spray head is provided with a water-cooled jacket.

6. The method for treating wastewater and organic waste liquid according to claim 1, wherein: When switching the injected substances in each channel in steps S1 and S2, it is necessary to ensure that the gasifier does not go out of fire.

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