CN210267235U - Plasma smelting furnace and hazardous waste treatment system - Google Patents

Abstract

A plasma furnace, hazardous waste treatment system, the plasma furnace comprising: the furnace body is internally provided with a hearth; the electrode holding lifting unit capable of automatically lifting is fixed on the furnace body, at least two direct current electrodes are fixed at the front end of the electrode holding lifting unit and extend into the hearth, and the distance between the ends of the direct current electrodes can be adjusted according to the working condition in the furnace and/or the direct current electrodes can be supplemented by pressure release according to the loss degree of the direct current electrodes; the direct current electrode is used for generating plasma electric arc with the slag in the hearth; the charging opening is arranged at the top of the furnace body; the slag outlet is arranged on the furnace body and communicated with the hearth; and the tapping hole is arranged at the bottom of the furnace body. The utility model discloses can avoid the production of dioxin, can also reliable and stable operation, energy consumption low, with low costs, longe-lived, the leakproofness is good, advantage such as maintenance is simple.

Description

Plasma smelting furnace and hazardous waste treatment system

Technical Field

The utility model relates to a hazardous waste incineration field, concretely relates to useless processing system of plasma smelting pot, danger.

Background

With the continuous development of economy, the production level is steadily improved, the hazardous waste is increased, the environmental pollution caused by the hazardous waste is increasingly serious, and the normal life of people is seriously influenced in partial areas. At the present stage, people have stronger and stronger environmental demands on green water of green mountains, and a series of environmental protection measures are added from eighteenth to eighteenth by governments, which are concerned with the welfare of people and the long-term and extensive future of nationalities. According to 2016 statistical data, the generation amount of industrial hazardous wastes in China increases year by year, and reaches 3976.11 ten thousand t in 2015, wherein the disposal amount accounts for 29%, the storage amount accounts for 20%, and the rest 51% is comprehensively utilized. Industrial hazardous wastes are distributed in different industries, mainly chemical raw material and chemical product manufacturing industry, non-ferrous metal smelting and mining and dressing industry, non-metallic ore mining and dressing industry and the like. When the hazardous waste is not properly treated, the hazardous waste can pose a serious threat to the nature and the human health, such as serious accidents of Changzhou poison pollution case, Jingjing pig farm underground landfill hazardous waste case, Shandong Qingdun hazardous waste dumping case and the like which occur in recent years, and the hazardous waste can cause serious influence. Compared with huge demands, the shortage of hazardous waste treatment capacity is the largest threshold of the current hazardous waste treatment market, the capacity expansion of the hazardous waste treatment market is limited by low technical level, no research and development follow-up and low enterprise capital, and the current technical equipment has a larger gap compared with the foreign well-known enterprises. In order to deal with a great variety of dangerous wastes, the general type and the applicability of equipment are particularly important, the treatment of the dangerous wastes cannot be limited to the traditional industry and the traditional technology, and the active research and the advance of the emerging thermal plasma technology are needed. Aiming at the solid waste treatment by the thermal plasma, a great deal of research work is carried out by various research units at home and abroad, and certain research results are obtained. The polychlorinated biphenyl is treated by a plasma torch in the department of Chinese academy of sciences, the treatment efficiency reaches 99.99 percent, and the emission standard is reached; xylonite and the like in Zhejiang university utilize direct-current double-anode plasma to treat simulated medical waste, and have good curing effect on heavy metals in the simulated medical waste; the direct current arc plasma adopted by Jiangmen and the like of Chinese institute of fertilizer combination plasma physics can safely treat low-level radioactive waste (LLRW), and the capture rates of strontium, cobalt and cesium are 99.7%, 44.5% and 18.6% respectively. Foreign research such as the czech plasma physical research institute Hlina and the like gasifies biomass by using a plasma torch, and can generate high-quality synthesis gas; the West House plasma company in America utilizes a plasma melting gasification system to treat 220t/d of domestic garbage and has been successfully operated commercially; israel environmental energy resources corporation developed pgm (plasma targeting) technology and has a near pilot plant scale plant to operate on low radioactive waste.

The plasma technology has natural advantages for the treatment of hazardous wastes, can treat wastes which are difficult to treat, has no negative influence on the environment, and can also recover valuable byproducts, thereby not only meeting the current continuous and severe environmental protection requirements, but also conforming to the principles of circular economy and sustainable development. On one hand, with the revision and expansion of the latest dangerous waste list, the dangerous waste treatment capacity of the chemical industry and other industries is more and more, so that the market demand is larger; on the other hand, the resource energy shortage in China at present has great demands on resource recycling, and these are opportunities of the thermal plasma technology. The plasma technology can realize the environment-friendly effect of zero emission and improve the economical efficiency of projects for treating the hazardous wastes, thereby attracting the attention of numerous scholars and enterprises and developing research, and believing that the plasma technology can certainly occupy a place in the future market by means of the outstanding superiority and the continuous improvement of energy efficiency in the near future.

However, at present, the domestic plasma technology is still in the primary stage, and a large-scale industrialized system is still not widely applied at home, so that a bottleneck needs to be solved mainly in the aspects of technology and cost. Technically, the plasma generator has short electrode life, is difficult to realize long-time operation, and the system design (a plasma reaction furnace, refractory materials and the like) is mainly based on the characteristics of feeding materials, so that the treatment systems of different wastes have large difference; high investment and high energy consumption make the plasma technology economically impractical to implement widely, thereby affecting the enthusiasm for investment and hindering industrialization of the technology. The problems have no doubt to prevent the rapid development and wide application of the technology, so that the research on the plasma technology needs to be continuously carried out in China, the efficient utilization and the cost reduction of the technology are promoted, and an excellent treatment scheme is brought to the domestic hazardous waste market.

The technical problem to be overcome at present is mainly reflected in the following aspects:

1. the existing plasma furnace electrode is heated by adopting a metal torch, the electrode is seriously corroded, the energy consumption is high, and the operation cost is high.

2. The required air compression nitrogen system and peripheral equipment increase the technical investment.

3. The traditional melting furnace can not realize the decomposition and the damage of toxic and harmful components in ash slag and can inhibit the generation of dioxin, particles, carbon black and NOX;

4. the existing melting furnace is not provided with a furnace bottom heat preservation heating system, so that the heat efficiency is low;

5. the service life of the existing melting furnace is short.

SUMMERY OF THE UTILITY MODEL

In view of the above, one of the main objects of the present invention is to provide a plasma furnace and a hazardous waste treatment system, so as to at least partially solve at least one of the above technical problems.

In order to achieve the above object, as one aspect of the present invention, there is provided a plasma furnace including:

the furnace body is internally provided with a hearth;

the electrode holding lifting unit capable of automatically lifting is fixed on the furnace body, at least two direct current electrodes are fixed at the front end of the electrode holding lifting unit and extend into the hearth, and the distance between the ends of the direct current electrodes can be adjusted according to the working condition in the furnace and/or the direct current electrodes can be supplemented by pressure release according to the loss degree of the direct current electrodes; the direct current electrode is used for generating plasma electric arc with the slag in the hearth;

the charging opening is arranged at the top of the furnace body;

the slag outlet is arranged on the furnace body and communicated with the hearth; and

and the tapping hole is arranged at the bottom of the furnace body.

As another aspect of the utility model, still provide a useless processing system of danger, include the plasma smelting pot as above.

Based on the above technical scheme can know, the utility model discloses a plasma smelting pot, useless processing system of danger and its application have one of following advantage at least for prior art:

(1) the incinerator made by the thermal plasma technology can avoid the generation of dioxin. The general incineration can generate strong carcinogen dioxin, which is mainly caused by low combustion temperature and incomplete combustion, the temperature of a common incinerator is about 800 ℃, the furnace temperature is inevitably lower than 700 ℃ when the ignition is started, the feeding and flameout are carried out midway, the temperature of an arc center of a plasma furnace is as high as 3500-4200 ℃, the average temperature in the incinerator is 1500 ℃, and the treated material can reach high temperature instantly due to high furnace temperature, fast combustion, short retention time and high efficiency; the environmental protection standard is high, no highly toxic substances such as dioxin and the like are generated, and secondary pollution to human bodies and the environment is avoided;

(2) the whole set of equipment is miniaturized, the structure is simpler, the device is convenient to operate, the starting and the stopping are quick, and the automatic control can be realized completely, so that the operation is safe and reliable;

(3) the thermal plasma technology has a great difference in the treatment of hazardous waste compared with the incineration mode. Firstly, the principle is different, the incineration is an oxygen-enriched combustion process, air needs to be added continuously, the temperature in the furnace is generally lower than 900 ℃, the plasma technology is an anoxic pyrolysis process, no extra oxygen is needed, and the average temperature in the furnace can reach more than 1500 ℃; the second difference is that the main products, the products of incineration are flue gas, cinders and fly ash, and the products of plasma technology are typically low calorific value syngas and vitreous hot slag. The thermal plasma technology has the specific advantages that the first is the reduction of waste, the ash volume is about one fifth of the ash volume generated by burning, and the reduction is made to the maximum extent; secondly, the waste is harmless, and the thermal plasma technology enables organic matters (including toxic and harmful substances such as dioxin, furan and the like) to be rapidly dehydrated, pyrolyzed and cracked; thirdly, the waste is recycled, the plasma melting furnace can form a stable glass solidified body, and the glass solidified body can be used as a building material or other materials after being detected to be qualified, so that the waste recycling is realized;

(4) the furnace body heat preservation heating system applies work by adopting a three-phase alternating current graphite electrode, has higher heat efficiency and more energy conservation, can continuously maintain the temperature of molten slurry in the molten pool, ensures the tapping temperature of the molten slurry, can ensure the normal work of the tapping system even if the direct current electrode breaks down and breaks the arc, and is beneficial to the arc striking of the direct current electrode because of the existence of the molten slurry in the molten pool when the direct current electrode breaks the arc and then strikes the arc again;

(5) the load distribution of the direct current electrode at the top of the furnace cover and the alternating current electrode at the bottom of the furnace body can be adjusted according to the characteristics of the materials so as to adapt to the materials with various characteristics;

(6) the utility model discloses a secondary dust that the melting of plasma furnace forms the stirring of dust in the stove is less than the plasma furnace of torch form, and the working gas of torch can stir the interior dust of stove, forms a large amount of secondary dust, and is great to follow-up burner gas purifier influence. The melting furnace of the utility model generates energy by plasma electric arc, and has no stirring effect on dust in the furnace;

(7) the melting furnace of the utility model also has the advantages of stable and reliable operation, low energy consumption, low cost, long service life, good sealing performance, simple maintenance and the like.

Drawings

Fig. 1 is a schematic sectional view of a plasma furnace for a hazardous waste treatment system according to an embodiment of the present invention;

fig. 2 is a schematic side view of a cross-sectional structure of a plasma furnace for a hazardous waste treatment system according to an embodiment of the present invention;

fig. 3 is a schematic top view of a plasma furnace for hazardous waste treatment system according to an embodiment of the present invention.

In the above figures, the reference numerals have the following meanings:

1-furnace body; 2-heat preservation heating system; 3-furnace cover; 4-an electrode holding lifting unit; 5-volume fixing; 6-a gate valve; 7-a feed hopper; 8-a smoke outlet; 9-discharging system; 10-iron notch.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings.

The utility model discloses a plasma smelting pot, include:

the furnace body is internally provided with a hearth;

the electrode holding lifting unit capable of automatically lifting is fixed on the furnace body, at least two direct current electrodes are fixed at the front end of the electrode holding lifting unit and extend into the hearth, and the distance between the ends of the direct current electrodes can be adjusted according to the working condition in the furnace and/or the direct current electrodes can be supplemented by pressure release according to the loss degree of the direct current electrodes; the direct current electrode is used for generating plasma electric arc with the slag in the hearth;

the charging opening is arranged at the top of the furnace body;

the slag outlet is arranged on the furnace body and communicated with the hearth; and

and the tapping hole is arranged at the bottom of the furnace body.

Wherein, the bottom of the hearth is a molten pool;

wherein, the molten pool is in an inverted cone shape;

wherein the bottom diameter of the molten pool is 300-1200mm, such as 429mm, and the frustum height of the molten pool is 100-500mm, such as 150 mm.

Wherein, the diameter of the hearth is 300-1400mm, such as 600mm, and the depth of the hearth is 600-3600mm, such as 930 mm;

wherein the diameter of the feed inlet is 200 mm;

wherein the power of the plasma furnace is 120-1000KW, such as 200 KW.

Wherein the top of the furnace body is provided with a furnace cover, and the feeding port is arranged on the furnace cover;

wherein, be equipped with the outlet flue that communicates with furnace on the bell.

Wherein, the bottom of the furnace body is provided with a heat preservation heating unit;

wherein the heat-preservation heating unit adopts a three-phase alternating-current graphite electrode;

wherein the graphite electrode has a diameter of 40-200mm, for example 75 mm;

wherein, the graphite electrodes are uniformly distributed at the bottom of the furnace body at 120 degrees;

wherein the graphite electrode has a load of 15 to 85%, for example 30%, of the total load.

Wherein the direct current electrode comprises an anode and a cathode;

wherein the included angle between the anode and the cathode is 15-60 degrees, such as 30 degrees;

wherein, the anode and the cathode are made of graphite;

wherein the anode and the cathode are both direct current electrodes;

wherein the diameter of the anode and cathode is 40-200mm, for example 75 mm;

the load of the electrode holding and lifting unit accounts for 30-85%, for example 70%, of the total load.

Wherein the charging hole is connected with a quantitative unit;

the quantitative unit is provided with double-layer gate valves, and a quantitative bin is formed between the double-layer gate valves;

wherein, the quantifying unit is provided with a feed hopper.

Wherein the slag outlet is provided with a heat-insulating cover;

wherein, the heat preservation covers and is equipped with the access door of being convenient for maintain the slag notch.

Wherein the included angle between the tapping hole and the horizontal plane is 5-20 degrees, such as 10 degrees;

wherein the size of the iron outlet is 60-200mm, for example 75 mm.

The utility model also discloses a useless processing system of danger, it is as above including to include the plasma smelting pot.

The plasma furnace as described above is used in the field of hazardous waste treatment.

The technical solution of the present invention is further explained by the following specific embodiments with reference to the attached drawings. It should be noted that the following specific examples are only illustrative, and the scope of the present invention is not limited thereto.

The utility model discloses an output of melting furnace is 840kg/d, installed capacity 200KW, and operating temperature is 1400 ~ 1600 ℃, and the plasma electrode adopts DC power supply and alternating current power supply, and during the operation, loading voltage between the graphite anode of direct current and graphite cathode to regard the slag as the dielectric to produce plasma electric arc, the three-phase exchanges graphite electrode and uses the magma to produce joule heat as conducting medium, for the molten bath heat preservation heating.

The melting furnace is mainly used for treating slag discharged after treatment of the rotary kiln and hazardous waste fly ash generated by a flue gas system, the waste entering the furnace is firstly mixed by a pretreatment system according to a certain raw material ratio and then enters the melting furnace for high-temperature treatment, the waste is melted by utilizing high temperature and activated groups generated by a plasma electrode, the discharged solidified body has stable performance, heavy metal is wrapped and fixed in a vitreous body grid formed by Si-O, and the melting furnace is nontoxic and harmless, is mainly used for providing a place for high-temperature melting treatment of solid waste to form a stable vitreous solidified body, and thus the waste is recycled.

The plasma melting furnace comprises a furnace body 1, a furnace cover 3, an electrode holding lifting unit 4, a furnace bottom heat preservation heating system 2, a slag hole 9, a feed hopper 7, a smoke outlet 8, an iron outlet 10 and the like, wherein the main body of the plasma melting furnace is a melting furnace body, and other parts of the plasma melting furnace are attached to the melting furnace body. The utility model discloses reached reliable and stable operation, energy consumption low, with low costs, longe-lived, the leakproofness good, maintain effect such as simple.

The melting furnace is characterized in that: the high energy density and high temperature of the thermal plasma and the fast reaction time can treat a large amount of waste in a smaller reactor; the graphite electrode does not need working gas and a large amount of air distribution in common incineration, so the required gas amount and the waste gas treatment amount are small. Two direct current graphite electrodes capable of automatically lifting and pressing are arranged at the top of the melting furnace and respectively comprise an anode and a cathode, the diameter of each direct current graphite electrode is 75mm, the arrangement included angle of the anode and the cathode is 30 degrees, and the load of each direct current electrode accounts for 70 percent of the total load and is 140 KW.

Wherein, the bottom of the melting furnace is provided with a heat preservation heating system 2, a three-phase alternating current graphite electrode is adopted, the diameter of the alternating current graphite electrode is 75mm, the three-phase alternating current graphite electrode is uniformly distributed at the bottom of the furnace at 120 degrees, and the load of the alternating current electrode accounts for 30 percent of the total load and is 60 KW.

Wherein, slag notch 9 is raised and is arranged, and 11 degrees with the horizontal plane contained angle, slag notch 9 diameter 100mm, and the melting furnace can keep the liquid level of molten bath, and liquid level height 133mm, and slag notch 9 and molten bath are linked into a whole, are convenient for conduct heat, and the temperature of slag notch 9 is unanimous basically with the molten bath temperature, can realize slagging tap in succession, makes the easy operation of slagging tap, because the existence in molten bath can make stove bottom heat preservation heating system continuous operation. The slag hole 9 is provided with a heat insulation cover for keeping the temperature of the slag hole 9, and the heat insulation cover is provided with an access door for facilitating the maintenance of the slag hole 9. The tap hole 10 is positioned at the bottom of the furnace, the included angle between the tap hole and the horizontal plane is 10 degrees, and the size of the tap hole 10 is 75 mm.

Wherein, furnace diameter 600mm, furnace degree of depth 930mm, the stove bottom is the back taper, and the stove bottom diameter is 429mm, and the frustum height is 150mm, and the furnace bottom structure of back taper does benefit to the formation of molten bath when blowing in initial solution is less, and the slag flows into the cooling slag box cooling of the vitreous body that holds water, forms the vitreous body.

Wherein, the charge door is in the positive center top of melting furnace bell, and the charge door size is DN200mm (the diameter is 200mm), and feeding device adopts double-deck push-pull valve, guarantees the sealed of reinforced in-process, is the constant volume storehouse between the push-pull valve, and the constant volume storehouse volume is 73 liters, and there is the feeder hopper constant volume storehouse top.

Waste is firstly mixed by a pretreatment system according to a certain raw material proportion, then is added into a feed hopper 7 at the top of a melting furnace, enters a quantitative bin through a gate valve at the outlet of the feed hopper 7, is quantitatively fed into a gate valve at the lower part, and enters a hearth through a feed inlet at the center of the top of a furnace cover. The plasma electrode is powered by a direct current power supply and an alternating current power supply, when the plasma electrode operates, voltage is loaded between a direct current graphite anode and a graphite cathode, slag is used as a dielectric to generate a plasma electric arc, the arc starting position of the direct current graphite anode and the graphite cathode is about 100-400mm away from the furnace bottom, the arc length is adjustable within 30-200mm, the generated molten slurry is collected into an inverted cone at the bottom of the furnace cavity to quickly form a molten pool, and the three-phase alternating current graphite electrode uses the molten slurry as a conductive medium to generate joule heat to heat the molten pool. The temperature of the molten pool is 1300-1600 ℃, the electric arc temperature is 3500-4200 ℃, and the molten slurry in the molten pool flows out of the slag cooling box through the slag outlet 9 for cooling and storage after reaching the tapping liquid level line (133 mm away from the furnace bottom) of the slag outlet 9. The high-temperature flue gas is discharged out of the hearth through the flue gas outlet 8 and then flows to a subsequent purification device. The graphite electrode is continuously consumed, and the electrode holds the lifting unit 4 to continuously press and release the graphite electrode for supplement. The materials are continuously added into the hearth and continuously melted, and molten slurry is continuously discharged from the furnace, so that the material inlet and outlet are balanced. After the production time is long, a lot of molten iron can be deposited on the bottom of the furnace, the tap hole 10 is opened periodically, and the molten iron is discharged, so that the melting furnace can be used for subsequent normal production.

The above-mentioned embodiments, further detailed description of the objects, technical solutions and advantages of the present invention, it should be understood that the above-mentioned embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (10)

1. A plasma furnace, comprising:

the furnace body is internally provided with a hearth;

the electrode holding lifting unit capable of automatically lifting is fixed on the furnace body, at least two direct current electrodes are fixed at the front end of the electrode holding lifting unit and extend into the hearth, and the distance between the ends of the direct current electrodes can be adjusted according to the working condition in the furnace and/or the direct current electrodes can be supplemented by pressure release according to the loss degree of the direct current electrodes; the direct current electrode is used for generating plasma electric arc with the slag in the hearth;

the charging opening is arranged at the top of the furnace body;

the slag outlet is arranged on the furnace body and communicated with the hearth; and

and the tapping hole is arranged at the bottom of the furnace body.

2. The plasma furnace of claim 1,

the bottom of the hearth is a molten pool;

the molten pool is in an inverted cone shape;

the bottom diameter of the molten pool is 300-1200mm, and the frustum height of the molten pool is 100-500 mm.

3. The plasma furnace of claim 1,

the diameter of the hearth is 300-1400mm, and the depth of the hearth is 600-3600 mm;

the diameter of the feed inlet is 200 mm;

the power of the plasma furnace is 120-1000 KW.

4. The plasma furnace of claim 1,

the top of the furnace body is provided with a furnace cover, and the feeding port is arranged on the furnace cover;

and a smoke outlet communicated with the hearth is formed in the furnace cover.

5. The plasma furnace of claim 1,

the bottom of the furnace body is provided with a heat-preservation heating unit;

the heat-preservation heating unit adopts a three-phase alternating-current graphite electrode;

the diameter of the graphite electrode is 40-200 mm;

the graphite electrodes are uniformly distributed at the bottom of the furnace body at 120 degrees;

the load of the graphite electrode accounts for 15-85% of the total load.

6. The plasma furnace of claim 1,

the direct current electrode comprises an anode and a cathode;

the included angle between the anode and the cathode is 15-60 degrees;

the anode and the cathode are made of graphite;

the anode and the cathode are both direct current electrodes;

the diameters of the anode and the cathode are 40-200 mm;

the load of the electrode holding lifting unit accounts for 30-85% of the total load.

7. The plasma furnace of claim 1,

the charging opening is connected with a quantitative unit;

the quantifying unit is provided with double-layer gate valves, and a quantifying bin is formed between the double-layer gate valves;

the quantitative unit is provided with a feed hopper.

8. The plasma furnace of claim 1,

the slag outlet is provided with a heat-insulating cover;

an access door convenient for maintaining a slag hole is arranged on the heat-insulating cover;

the included angle between the tapping hole and the horizontal plane is 5-20 degrees.

9. The plasma furnace of claim 8,

the size of the iron notch is 60-200 mm.

10. A hazardous waste treatment system comprising a plasma furnace according to any one of claims 1 to 9.

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