CN110145749A - A system and method for safe incineration disposal of hyperaccumulator plants - Google Patents

Abstract

The invention discloses a safe incineration disposal system and method for super-enriched plants, including an incinerator, a secondary combustion chamber, a primary heat exchanger, a secondary heat exchanger, a primary dust collector, a secondary dust collector, an exhaust fan and a washing tower The side wall of the incinerator is provided with a burner, and the flue gas outlet of the incinerator is connected to the second combustion chamber, the primary heat exchanger, the secondary heat exchanger, the primary dust collector, and the secondary combustion chamber in sequence through pipelines. Secondary dust collector, exhaust fan and scrubber. The present invention can effectively treat heavy metal elements, dust, sulfide and other harmful substances in the tail gas through double incineration, double cooling, secondary dust removal, and spray washing, so as to realize the safe reduction of enriched plants.

Description

A system and method for safe incineration disposal of hyperaccumulator plants

technical field

The invention belongs to the technical field of hyperaccumulator plant disposal, and in particular relates to a system and method for safe incineration disposal of hyperaccumulator plants.

Background technique

As a kind of bioremediation technology, phytoremediation technology has the advantages of low repair cost, environmental friendliness, no secondary pollution, and no damage to soil structure, etc. It can also improve soil ecology, reduce soil erosion, and increase carbon fixation. In recent years, it has been widely used in the remediation of heavy metal-contaminated soil and is a green remediation method.

As more and more hyperaccumulator plants are discovered, the biomass of enrichment plants used for remediation of heavy metal-contaminated soils increases sharply, which will cause secondary pollution if not treated. Methods for dealing with hyperaccumulators include incineration, composting, compressed landfill, liquid phase extraction, and pyrolysis. Among them, the incineration method is the most efficient and convenient method for reducing the amount of enriched plants. However, the tail gas produced during the incineration process and the heavy metals in the tail gas must be properly controlled. At present, a set of effective technologies that can be widely used in the incineration treatment of enriched plants has not been formed in the enriched plant treatment market.

Contents of the invention

This application aims to solve at least one of the technical problems existing in the prior art. For this reason, one of the objects of the present invention is to provide a system and method for safe incineration of super-enriched plants, which can effectively treat heavy metal elements and dust in the tail gas through double burning, double cooling, secondary dust removal, and spray washing. Harmful substances such as sulfides can be safely reduced by enriching plants.

In order to solve the above technical problems, the application adopts the following technical solutions:

A safe incineration disposal system for super-enriched plants, characterized in that it includes an incinerator, a secondary combustion chamber, a primary heat exchanger, a secondary heat exchanger, a primary dust collector, a secondary dust collector, an exhaust fan and a washing tower; The side wall of the incinerator is provided with a burner, and the flue gas outlet of the incinerator is connected to the second combustion chamber, the primary heat exchanger, the secondary heat exchanger, the primary dust collector, and the secondary dust collector in sequence through pipelines. devices, exhaust fans and scrubbers.

Further, the incinerator is provided with a furnace temperature sensor and a furnace pressure sensor, and a reciprocating fire grate is arranged inside.

Further, the primary heat exchanger adopts a water-cooled heat exchanger, and the secondary heat exchanger adopts an air heat exchanger, and the hot air heated by the air heat exchanger is introduced into the incinerator and the secondary combustion chamber by a blower. .

Further, the secondary combustion chamber adopts a cyclone separator type secondary combustion chamber, and a secondary combustion chamber temperature sensor and a secondary combustion chamber pressure sensor are arranged in it.

Further, the primary dust collector is a cyclone dust collector, and the secondary dust collector is a bag filter.

Further, an over-temperature alarm valve is provided on the pipeline connecting the primary dust collector and the secondary dust collector.

Further, the washing tower adopts a multi-layer structure with three layers of washing and two layers of demisting.

Further, a chimney is connected after the washing tower.

A method for safe incineration disposal of hyperaccumulator plants, comprising the steps of:

Crushing and granulating hyperaccumulator plants;

Put the crushed and granulated super-enriched plants into the incinerator for high-temperature pyrolysis and combustion, and the combustion temperature is about 800-1000 °C;

The high-temperature flue gas after incineration enters the secondary combustion chamber, and the incompletely decomposed organic substances in the high-temperature flue gas are further burned in an oxygen-enriched state;

The high-temperature flue gas from the second combustion chamber is double-cooled by the water-cooled heat exchanger and the air heat exchanger, and the temperature drops below 200°C;

The cooled flue gas enters the cyclone dust collector and bag filter for secondary dust removal;

The flue gas after secondary dust removal enters the spray scrubber, removes inert harmful gases and small particle dust through the spray scrubber, and finally discharges through the chimney up to the standard.

Further, the following steps are also included: the fresh air is introduced into the incinerator and the secondary combustion chamber by the blower through the air heat exchanger for heat exchange and temperature rise.

Compared with the prior art, the present invention has the beneficial effects of:

1. Heavy metal elements, dust, sulfide and other harmful substances in the tail gas can be effectively treated through double incineration, double cooling, double dust removal, and spray washing, and the tail gas emission after disposal can fully meet the national or regional standards.

2. Dry dust removal is adopted, the process is reliable, and the required investment is small.

3. The fresh air passes through the air heat exchanger for heat exchange and temperature rise, and is introduced into the incinerator and the secondary combustion chamber by the blower, and the energy is reused, and the operating cost is low.

4. The equipment is modularized, easy to install and disassemble, and can be transported to the next area after repairing one area.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Among them: 1-lifting feeding mechanism; 2-incinerator; 3-igniter; 4-second combustion chamber; 5-pipeline; 6-water-cooled heat exchanger; 7-air heat exchanger; 8-cyclone dust collector; 9-over-temperature alarm valve; 10-bag filter; 11-exhaust fan; 12-washing tower; 13-chimney.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Referring to Fig. 1, a safe incineration disposal system for super-enriched plants includes an incinerator 2, a secondary combustion chamber 4, a water-cooled heat exchanger 6, an air heat exchanger 7, a cyclone dust collector 8, a bag filter 10, and an exhaust fan 11 , scrubber 12, chimney 13, blower, control system, etc. The flue gas outlet of the incinerator 2 is connected to the second combustion chamber 4, water-cooled heat exchanger 6, air heat exchanger 7, cyclone dust collector 8, bag filter 10, exhaust fan 11, washing tower 12 and A chimney 13 is provided with a burner 3 on the side wall of the incinerator 2 .

In this embodiment, cyclone dust removal, 8 is used for dust pre-dedusting, and is composed of cyclone barrel, dust collecting hopper, and wind collecting cap. The bag filter 10 adopts a high-efficiency filter dust collector, and the filtering effect can reach 99.9%. It is mainly composed of upper box, middle box, lower box, steel bracket and ash hopper. The filter bag is made of high temperature resistant material. The dust collector has a built-in pulse blowback device, which can automatically clean dust.

There is an over-temperature alarm valve 9 between the cyclone dust collector 8 and the bag filter 10. The over-temperature alarm valve 9 can monitor the temperature of the pipeline system in real time to avoid damage to the bag filter 10 caused by flue gas when the temperature is too high .

Exhaust fan 11 adopts high-pressure centrifugal fan, which is composed of shell, shaft, impeller, bearing, motor, belt and other components, so that the whole system is in a negative pressure state. The chimney 13 is used to discharge purified flue gas, and there are monitoring devices for online temperature, pressure, SO _x , NO _x , and heavy metal elements on the chimney.

In this embodiment, heavy metal elements, dust, sulfide and other harmful substances in the tail gas can be effectively treated through double incineration, double cooling, double dust removal, and spray washing, so as to realize the safe reduction of enriched plants, and the tail gas after disposal Emissions fully meet national or regional standards.

Referring to Fig. 1, in one embodiment, in the disposal system of this embodiment, the incinerator 2 adopts a reciprocating grate furnace structure, the furnace structure is multi-pass, the refractory brick furnace wall is built by masonry, and aluminum silicate high-temperature-resistant materials are poured for external use Rock wool insulation. The incinerator uses air as the medium and is equipped with an automatic ignition device to fully incinerate the material in the furnace, and the temperature in the furnace can reach 900°C. There are a furnace temperature sensor and a furnace pressure sensor (not shown in the figure) in the furnace to monitor the temperature and pressure in the furnace online. There are two burners 3, which are used in the incinerator 2 and the secondary combustion chamber 4 respectively to provide power for material combustion. The secondary combustion chamber 4 adopts a cyclone separator type secondary combustion chamber, which is a vertical double-return structure, and is equipped with an explosion-proof port for secondary combustion of the flue gas. The secondary combustion chamber 4 has a secondary combustion chamber temperature sensor and a secondary combustion chamber pressure. A sensor (not shown in the figure) monitors the temperature and pressure in the secondary combustion chamber online.

It should be noted that in actual design, the washing tower 12 adopts a multi-layer structure with three layers of washing and two layers of demisting, which can fully wash the flue gas and realize the purification of the flue gas.

Referring to Fig. 1, in another embodiment, in the disposal system of this embodiment, the water-cooled heat exchanger 6 adopts an indirect water cooling method, and a plurality of carbon steel water pipes are built in. The cold water flows in the pipes, and the high-temperature flue gas passes outside the pipes, which can Rapidly lower the temperature of the flue gas to 300°C. The air heat exchanger 7 has built-in multiple air pipes made of carbon steel, the flue gas passes through the air pipes, and the fresh cold air inside the pipes further cools the flue gas down to below 200°C. The fresh cold air is affected by the high-temperature flue gas, and the temperature will rise to 70°C. It is introduced into the incinerator 2 and the second combustion chamber 4 by the blower. While supplementing fresh air for the material combustion, avoid the incinerator 2 and the second combustion chamber 4 as much as possible. The temperature is lowered, thereby saving the energy consumption of the system. The temperature sensor of the second combustion chamber, the pressure sensor of the second combustion chamber, the furnace temperature sensor, the furnace pressure sensor, the exhaust fan, the over-temperature alarm valve and the blower are electrically connected to the control system. As for the specific composition of the control system, they are all conventional designs in the field of electric control , which will not be repeated here.

The following will take the safe incineration disposal of heavy metal hyperaccumulator plants such as grain amaranth as an example to illustrate the specific process of using the safe incineration disposal system for enriched plants of this application to process grain amaranth:

The bulk density of the plants to be disposed is high, which is not conducive to feeding; it occupies a large volume of the furnace and has poor combustion characteristics. Therefore, the material needs to be crushed first in order to reduce the volume (the crushed material is 5-8mm), and at the same time, it is convenient for granulation, transportation, storage, etc. Then granulate (particle size is ), after granulation, it can improve the combustion characteristics of the material, increase the calorific value, increase the fuel density, and facilitate feeding and bagging storage.

The granulated raw material is similar to biomass granules, and its special feature is that it contains heavy metal elements. Therefore, it is necessary to carry out reasonable treatment of exhaust gas. The specific treatment is as follows:

(1) The lifting feeding mechanism 1 puts the waste into the combustion chamber of the incinerator 2 through the hopper. Under the combustion-supporting action of the burner 3 and the air disturbance provided by the blower, the waste is burned according to the three-T principle of combustion (temperature, time, swirl flow) ) is pyrolyzed and burned at high temperature in the furnace, the combustion temperature is about 800-1000°C, and the whole combustion process is in a negative pressure state. The material reduction rate after incineration is over 90%.

Specifically, the lifting and feeding mechanism 1 includes components such as a hopper, a motor, an electric push rod, and a chain. The electric push rod drives the chain up and down, and lifts the hopper from the bottom to the top to realize automatic feeding of materials and has an automatic weighing function. .

(2) The high-temperature flue gas after incineration enters the second combustion chamber 4, and the second combustion chamber 4 is a furnace with a vertical cylindrical inner wall lined with refractory materials. The furnace body adopts a cyclone structure, and the oxygen supply air is supplied tangentially to enhance the disturbance to ensure the full gasification of organic matter. Due to the supplement of oxidizing air in the oxidation zone of the furnace body, the oxidation zone is in an oxygen-enriched state, and the incompletely decomposed organic substances in the high-temperature flue gas are further burned in an oxygen-enriched state, and a longer residence time is ensured, so that the organic waste can be completely discharged here. break down.

(3) The temperature of the flue gas coming out of the second combustion chamber 4 is as high as 1100°C, and the flue gas needs to be cooled by water cooling and air cooling. The high temperature flue gas is cooled by the water cooling heat exchanger 6 and the air heat exchanger 7. Below 200°C; after fresh air enters the air heat exchanger 6, the temperature can rise to 60-70°C, and the blower is used for the incinerator 2 and the second combustion chamber 4, which effectively saves energy consumption.

(4) The flue gas after cooling is removed by the cyclone dust collector 8 to remove large particles of dust, which effectively reduces the workload of the bag filter 10 . There is an over-temperature alarm valve 9 between the cyclone dust collector 8 and the bag dust collector 10 to prevent damage to the filter bag of the bag dust collector due to excessive flue gas temperature. After that, the flue gas enters the bag filter 10 for high-efficiency filtration.

(5) The flue gas after dust removal enters the spray scrubber 12, and absorbs and removes harmful gases and small particles of dust by spraying a specially equipped solution to achieve non-toxic, smoke-free, harmless, and odorless effects. After defoaming treatment After reaching the standard gas introduction chimney 13 is discharged into atmosphere.

(6) The whole system is also equipped with an emergency discharge system. Once the incinerator system fails, the pneumatic switching valve will act instantly, and the flue gas will be emptied by the emergency discharge system to ensure the safe operation of the system.

(7) The ash and slag produced by the incineration system are mainly metal oxides, which belong to the hazardous waste category. After being collected in a unified manner, the hazardous waste manufacturers will conduct centralized treatment; the waste water produced by the incineration system is mainly the cooling water for the system and the circulation of the circulation pool Water, after sedimentation treatment, regularly enters the sewage pipe network system for treatment; the waste gas generated by the incineration system can fully achieve standard discharge after treatment.

The above-mentioned embodiments are only examples for clearly illustrating the present invention, rather than limiting the implementation. For those of ordinary skill in the art, on the basis of the above description, other changes or changes in different forms can also be made. It is not necessary and impossible to exhaustively list all the embodiments here. However, the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims (10)

1. a kind of safe incineration disposal system of super enriching plant, it is characterised in that: including incinerator, dual firing chamber, a heat exchanger, Secondary heat exchanger, disposable dust remover, secondary filter, exhaust blower and scrubbing tower；The side wall of the incinerator is equipped with burner, The exhanst gas outlet of the incinerator is in turn connected to the dual firing chamber by pipeline, a heat exchanger, secondary heat exchanger, once removes Dirt device, secondary filter, exhaust blower and scrubbing tower.

2. disposal system according to claim 1, it is characterised in that: the incinerator be equipped with fire box temperature sensor and Furnace pressure sensor, inside are equipped with reciprocal grate.

3. disposal system according to claim 1, it is characterised in that: a heat exchanger uses water cooling heat exchanger, institute Secondary heat exchanger is stated using air heat exchanger, the hot-air after the air heat exchanger heating introduces the incinerator by air blower And dual firing chamber.

4. disposal system according to claim 1, it is characterised in that: the dual firing chamber is fired using cyclone type two Room, it is interior to be equipped with dual firing chamber's temperature sensor and dual firing chamber's pressure sensor.

5. disposal system according to claim 1, it is characterised in that: the disposable dust remover uses cyclone dust collectors, institute Secondary filter is stated using bag filter.

6. disposal system according to claim 1, it is characterised in that: connect the disposable dust remover and secondary filter Pipeline is equipped with overtemperature alarm valve.

7. disposal system according to claim 1, it is characterised in that: the scrubbing tower is using three layers of washing, two layers of demisting Multilayered structure.

8. disposal system according to claim 1, it is characterised in that: the scrubbing tower is connected with chimney.

9. a kind of safe incineration disposal method of super enriching plant, which comprises the steps of:

By the broken granulation of super enriching plant；

By high temperature pyrolysis burning in the super enriching plant investment incinerator after broken granulation, ignition temperature is controlled in 800-1000 ℃；

High-temperature flue gas after burning enters dual firing chamber, and the organic substance not decomposed completely in high-temperature flue gas is under oxygen-enriched state into one Step burning；

The high-temperature flue gas come out through dual firing chamber drops to 200 DEG C or less by water cooling heat exchanger and the dual cooling of air heat exchanger；

Flue gas after cooling enters cyclone dust collectors and bag filter, carries out final dusting；

Flue gas after final dusting enters spray scrubber, removes inertia pernicious gas and little particle powder by spray scrubber Dirt, eventually by chimney qualified discharge.

10. method of disposal according to claim 9, which comprises the steps of: fresh air is changed by air Hot device heat exchange heating introduces incinerator and dual firing chamber by air blower.