CN114353101A

CN114353101A - Heat recycling method suitable for waste treatment and waste treatment system

Info

Publication number: CN114353101A
Application number: CN202111515180.3A
Authority: CN
Inventors: 汪洪伟; 黄伟; 郝峰
Original assignee: Beijing Meifulai Environmental Protection Engineering Co ltd
Current assignee: Beijing Meifulai Environmental Protection Engineering Co ltd
Priority date: 2021-12-13
Filing date: 2021-12-13
Publication date: 2022-04-15

Abstract

The invention provides a heat recycling method and a waste treatment system suitable for waste treatment, comprising the following steps: the combustion device is used for carrying out combustion treatment on the dangerous waste to generate smoke; the heat conduction oil furnace is arranged at the combustion device and communicated with the combustion device; the waste heat boiler is communicated with the heat conduction oil furnace and is used for absorbing the heat of the smoke of the waste heat boiler to heat the soft water in the waste heat boiler; the treatment device is communicated with the waste heat boiler and is used for deacidifying, dedusting and demisting the flue gas passing through the treatment device; the GGH heat exchanger comprises a GGH heating structure and a GGH flowing structure; the flue gas heater comprises a flue gas heating structure and a flue gas flowing structure, the flue gas heating structure is communicated with the heat-conducting oil furnace, the flue gas flowing structure is communicated with the GGH flowing structure, and heat-conducting oil in the flue gas heating structure heats flue gas in the GGH heat exchanger; a catalytic device; the catalytic device is communicated with the GGH heating structure, so that the catalyzed flue gas flows into the GGH heating structure; the GGH heating structure is communicated with an induced draft fan and a chimney.

Description

Heat recycling method suitable for waste treatment and waste treatment system

Technical Field

The invention relates to the technical field of environmental protection, in particular to a heat recycling method and a waste treatment system suitable for waste treatment.

Background

When solid, semi-solid and liquid hazardous wastes are treated, combustion treatment is needed, and after the combustion treatment, deacidification, dust removal and other operations are needed on flue gas generated by combustion, so that harmful gas generated after the solid, semi-solid and liquid hazardous wastes are treated can be treated.

When harmful gas is treated, according to different treatment processes, the harmful gas needs to be cooled firstly, the cooled harmful gas can be deacidified and dedusted, the harmful gas treatment after deacidification and dedusting needs to be heated again by using auxiliary fuel for catalytic reaction, the harmful gas is subjected to multiple heat absorption and heat release processes when being heated, cooled and the like, the heat release of the harmful gas cannot be effectively utilized in the prior art, and the heat utilization rate is low during waste treatment, so that the method is uneconomical and environmentally-friendly.

Disclosure of Invention

The embodiment of the invention provides a heat recycling method and a waste treatment system suitable for waste treatment, which can recycle heat generated during waste combustion, and have higher heat recycling rate, so that the technical scheme provided by the invention is more economic and environment-friendly.

In a first aspect of embodiments of the present invention, there is provided a heat recovery method suitable for waste treatment, comprising:

a heat conduction oil furnace is arranged in the combustion device, and waste is combusted in the combustion device to heat conduction oil in the heat conduction oil furnace;

cooling the flue gas in the combustion device through a quench tower, and then performing deacidification, dust removal and demisting treatment to ensure that the treated flue gas reaches 60-80 ℃;

60-80 ℃ of flue gas is heated to 170-190 ℃ through the GGH heat exchanger;

the flue gas with the temperature of 170-190 ℃ is heated to 240-260 ℃ at the flue gas heater, the flue gas heater is communicated with the heat conduction oil furnace, and heat conduction oil in the heat conduction oil furnace flows into the flue gas heater from the heat conduction oil furnace and heats the flue gas with the temperature of 170-190 ℃ to 230-250 ℃;

carrying out catalytic reaction on the flue gas at 230-250 ℃ by using a denitration catalytic reaction tower, wherein the temperature of the flue gas after catalytic reaction reaches 230-240 ℃;

inputting the flue gas with the temperature of 230-240 ℃ to a GGH heat exchanger to heat the flue gas with the temperature of 60-80 ℃ flowing through the GGH heat exchanger, and reducing the flue gas with the temperature of 230-240 ℃ after heat exchange to 120-140 ℃;

and generating negative pressure through the induced draft fan to discharge the flue gas flowing through the GGH heat exchanger at 120-140 degrees through a chimney.

Optionally, in a possible implementation manner of the first aspect, a heat conduction oil exchanger is arranged in the heat conduction oil furnace, and heat conduction oil is arranged in the heat conduction oil exchanger in advance;

a flue gas heating structure and a flue gas flowing structure are arranged in the flue gas heater;

the flue gas heating structure is communicated with the heat conduction oil exchanger, so that heat conduction oil flows through the flue gas heating structure, flue gas with the temperature of 170-190 ℃ flows through the flue gas flowing structure, and the heat conduction oil in the flue gas heating structure heats the flue gas with the temperature of 170-190 ℃ in the flue gas flowing structure.

Optionally, in one possible implementation manner of the first aspect, a GGH heating structure and a GGH flow structure are provided in the GGH heat exchanger;

enabling 60-80 degrees of flue gas to flow through the GGH flow structure;

and enabling the flue gas with the temperature of 230-250 ℃ to flow through the GGH heating structure.

In a second aspect of embodiments of the present invention, there is provided a waste treatment system comprising:

the combustion device is used for carrying out combustion treatment on the dangerous waste to generate smoke;

the heat conduction oil furnace is arranged at the combustion device, is communicated with the combustion device and is used for absorbing the heat of the smoke flowing through the heat conduction oil furnace to heat the heat conduction oil in the heat conduction oil furnace;

the waste heat boiler is communicated with the heat conduction oil furnace and is used for absorbing the heat of the smoke of the waste heat boiler to heat the soft water in the waste heat boiler;

the treatment device is communicated with the waste heat boiler and is used for deacidifying, dedusting and demisting the flue gas flowing through the treatment device;

the GGH heat exchanger comprises a GGH heating structure and a GGH flowing structure, and the GGH flowing structure is communicated with the processing device to enable flue gas output by the waste heat boiler to flow to the GGH flowing structure;

the flue gas heater comprises a flue gas heating structure and a flue gas flowing structure, the flue gas heating structure is communicated with the heat-conducting oil furnace, the flue gas flowing structure is communicated with the GGH flowing structure, and heat-conducting oil in the flue gas heating structure heats flue gas in the GGH heat exchanger;

the catalytic device is communicated with the flue gas flowing structure and is used for carrying out catalytic treatment on the flue gas output by the flue gas flowing structure;

the catalytic device is communicated with the GGH heating structure and is used for enabling the catalyzed flue gas to flow into the GGH heating structure;

the GGH heating structure is communicated with an induced draft fan and a chimney.

Optionally, in one possible implementation manner of the second aspect, the combustion apparatus includes:

a feed device for receiving solid, semi-solid hazardous waste;

the rotary kiln is connected with the feeding device, and the feeding device pours solid and semi-solid dangerous wastes into the rotary kiln;

and the second combustion chamber is communicated with the rotary kiln and is used for generating flue gas by burning solid and semi-solid hazardous wastes, and the second combustion chamber is communicated with the heat-conducting oil furnace and is used for transferring the heat of the flue gas to the heat-conducting oil furnace.

Optionally, in a possible implementation manner of the second aspect, a nozzle is arranged in the rotary kiln, and the nozzle is used for spraying liquid dangerous waste into the rotary kiln;

high-calorific-value waste liquid is respectively fed into the rotary kiln and the secondary combustion chamber;

and cleaning slag in the rotary kiln and the secondary chamber through a slag discharging machine.

Optionally, in a possible implementation manner of the second aspect, the processing device includes:

the quenching tower is communicated with the waste heat boiler and is used for cooling the flue gas flowing through the waste heat boiler, and washing water is injected into the quenching tower;

the dry deacidification tower is communicated with the quenching tower and is used for performing dry deacidification treatment on the flue gas output by the quenching tower, and slaked lime and activated carbon are injected into the dry deacidification tower;

the bag type dust collector is communicated with the dry-method deacidification tower and is used for dedusting the flue gas output by the dry-method deacidification tower;

the two-stage wet deacidification tower and the wet electric demister which are sequentially connected are used for deacidifying and demisting the flue gas output by the bag type dust collector, sodium hydroxide is respectively injected into the two-stage wet deacidification tower and the wet electric demister, and the wet electric demister is communicated with the GGH flow structure.

Optionally, in a possible implementation manner of the second aspect, a fly ash bin is connected to the bag filter, and the fly ash bin is used for processing dust collected by the bag filter.

Optionally, in one possible implementation manner of the second aspect, the catalytic device comprises a mixer and an SCR + dioxin catalytic reaction tower which are connected in sequence;

the mixer is communicated with the flue gas flowing structure and is used for mixing the flue gas with 10 percent of ammonia water;

catalyzing the mixed flue gas by an SCR + dioxin catalytic reaction tower to obtain catalyzed flue gas;

and transferring the catalyzed flue gas to a GGH heating structure.

Optionally, in a possible implementation manner of the second aspect, the GGH heating structure includes a first heating channel and a first heated channel, wherein flue gas at 230 to 240 degrees flows through the first heating channel, and flue gas at 60 to 80 degrees flows through the first heated channel;

the first heating channel is provided with a first temperature sensor, the first heated channel is provided with a second temperature sensor, the first temperature sensor can monitor the flue gas at 230-240 ℃ of the first heating channel to obtain a first heated value, and the second temperature sensor can monitor the flue gas at 60-80 ℃ of the first heated channel to obtain a first heated value;

acquiring the gas flow of the first heated channel at the current moment through a gas flow sensor, regulating and controlling the gas flow at the current moment based on a first heating numerical value and a first heated numerical value to obtain regulated and controlled gas flow, and regulating the power of the induced draft fan according to the regulated and controlled gas flow;

the regulated gas flow is obtained by the following formula,

wherein L is₁For regulated gas flow, L₂For regulating the gas flow before regulation, U is the current regulation coefficient, X is a preset regulation index,

is the first heating value, Q, at the ith moment in the previous preset time period₁Is a first predetermined temperature value, N is the number of first heating values in a previous predetermined time period,

is the first heating value, Q, at the kth moment in the previous preset time period₂The second predetermined temperature value is M, which is the number of the first heating values in the previous predetermined time period.

According to the heat recycling method and the waste treatment system suitable for waste treatment, provided by the invention, heat generated during waste combustion can be recycled through heat conduction oil, and flue gas with low temperature flowing through the flue gas heater is heated through the heat conduction oil, so that the temperature of the flue gas is increased. The gas to be discharged is recycled through the GGH heating structure, so that the gas after catalytic reaction heats the deacidified and demisted gas, and heat recovery and recycling are realized. According to the invention, the heat conduction oil is used as a heat medium, and the flue gas is used as a heat medium to heat the flue gas respectively, so that the heat utilization efficiency is improved, and meanwhile, no additional auxiliary fuel is consumed, and the method is more economic and environment-friendly.

Drawings

FIG. 1 is a flow diagram of a heat recovery process suitable for waste treatment;

fig. 2 is a schematic view of a connection structure of the waste treatment system.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein.

It should be understood that, in various embodiments of the present invention, the sequence numbers of the processes do not mean the execution sequence, and the execution sequence of the processes should be determined by the functions and the internal logic of the processes, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

It should be understood that in the present application, "comprising" and "having" and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

It should be understood that, in the present invention, "a plurality" means two or more. "and/or" is merely an association describing an associated object, meaning that three relationships may exist, for example, and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "comprises A, B and C" and "comprises A, B, C" means that all three of A, B, C comprise, "comprises A, B or C" means that one of A, B, C comprises, "comprises A, B and/or C" means that any 1 or any 2 or 3 of A, B, C comprises.

It should be understood that in the present invention, "B corresponding to a", "a corresponds to B", or "B corresponds to a" means that B is associated with a, and B can be determined from a. Determining B from a does not mean determining B from a alone, but may be determined from a and/or other information. And the matching of A and B means that the similarity of A and B is greater than or equal to a preset threshold value.

As used herein, "if" may be interpreted as "at … …" or "when … …" or "in response to a determination" or "in response to a detection", depending on the context.

The technical solution of the present invention will be described in detail below with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.

The invention provides a heat recycling method suitable for waste treatment, which is a flow chart shown in figure 1 and comprises the following steps:

and S110, arranging a heat conduction oil furnace in the combustion device, and burning the wastes in the combustion device to generate smoke to heat the heat conduction oil in the heat conduction oil furnace.

Step S120, cooling the flue gas in the combustion device through a quench tower, and then performing deacidification, dust removal and demisting treatment to enable the treated flue gas to reach 60-80 ℃;

s130, heating the flue gas at 60-80 ℃ to 170-190 ℃ through a GGH heat exchanger;

s140, heating the flue gas with the temperature of 170-190 ℃ to 240-260 ℃ at a flue gas heater, communicating the flue gas heater with a heat conduction oil furnace, and allowing heat conduction oil in the heat conduction oil furnace to flow into the flue gas heater from the heat conduction oil furnace to heat the flue gas with the temperature of 170-190 ℃ to 230-250 ℃;

s150, carrying out catalytic reaction on the flue gas at the temperature of 230-250 ℃ by using a denitration catalytic reaction tower, wherein the temperature of the flue gas after the catalytic reaction reaches 230-240 ℃;

step S160, inputting the flue gas with the temperature of 230-240 ℃ to a GGH heat exchanger to heat the flue gas with the temperature of 60-80 ℃ flowing through the GGH heat exchanger, and reducing the flue gas with the temperature of 230-240 ℃ after heat exchange to 120-140 ℃;

and S170, generating negative pressure through an induced draft fan, and discharging the flue gas flowing through the GGH heat exchanger at 120-140 degrees through a chimney.

According to the technical scheme provided by the invention, heat generated during waste combustion can be recycled through the heat conduction oil, and the flue gas with lower temperature flowing through the flue gas heater is heated through the heat conduction oil, so that the temperature of the flue gas is increased. The gas to be discharged is recycled through the GGH heating structure, so that the gas after catalytic reaction heats the deacidified and demisted gas, and heat recovery and recycling are realized. According to the invention, the heat conduction oil is used as a heat medium, and the flue gas is used as a heat medium to heat the flue gas respectively, so that the heat utilization efficiency is improved.

According to the technical scheme provided by the invention, preferably, a heat conduction oil exchanger is arranged in the heat conduction oil furnace, and heat conduction oil is arranged in the heat conduction oil exchanger in advance;

According to the technical scheme provided by the invention, preferably, a GGH heating structure and a GGH flowing structure are arranged in the GGH heat exchanger;

enabling 60-80 degrees of flue gas to flow through the GGH flow structure;

The technical scheme provided by the invention further comprises the following steps:

the GGH heating structure comprises a first heating channel and a first heated channel, wherein flue gas with the temperature of 230-240 ℃ flows through the first heating channel, and flue gas with the temperature of 60-80 ℃ flows through the first heated channel.

First heating passageway department sets up first temperature sensor first passageway department of being heated sets up second temperature sensor, can monitor the flue gas of 230 degrees to 240 degrees of first heating passageway through first temperature sensor and obtain first heating numerical value, can monitor the flue gas of 60 degrees to 80 degrees of first passageway of being heated through second temperature sensor and obtain first numerical value of being heated.

The gas flow of the first heated channel at the current moment is obtained through the gas flow sensor, the gas flow at the current moment is regulated and controlled based on the first heating numerical value and the first heated numerical value to obtain the regulated and controlled gas flow, and the power of the induced draft fan is adjusted according to the regulated and controlled gas flow.

The regulated gas flow is obtained by the following formula,

According to the technical scheme provided by the invention, a previous preset time period can be preset, the previous preset time period can be 10 seconds, one minute and the like, the time in the invention can also be 1 second, for example, when the previous preset time period is 10 seconds, the time is 10, and the time passes through

The average value of the first heating values at 10 moments within the preset time period can be counted by

The average value of the first heating values at 10 time points within the preset time period may be counted. Q₁And Q₂May be preset with a first preset temperature value of 230 degrees and a first heating value of 80 degrees, if

The larger, the higher the flue gas temperature in the first heating channel is proved, if

The larger the flue gas temperature in the first heated channel is, the lower is the evidence. Therefore, it is not only easy to use

The heating relation of the smoke can be reflected,

the more value ofThe heating effect is better proved if the temperature of the heated flue gas is higher;

the lower the value of (a), the lower the temperature of the heated flue gas after being heated, the poorer the heating effect is proved.

The invention can preset a regulation index, and the regulation index is compared with the regulation index

And obtaining a regulation and control coefficient U, wherein the regulation and control coefficient is positive, the heating effect is better, the regulation and control coefficient U is a positive value, and the gas flow can be increased. The regulation and control coefficient is negative, and then proves that the heating effect is worse, and the regulation and control coefficient U is a negative value at the moment, so that the gas flow can be reduced, the heating time of the flue gas can be longer, and the heating time of the flue gas can be prolonged.

According to the technical scheme, the temperature of the flue gas in the first heating channel and the first heated channel of the GGH heating structure can be monitored, and the flow speed of the flue gas in the first heated channel is dynamically adjusted according to the temperature of the flue gas in the first heating channel and the first heated channel, so that the flue gas in the first heated channel can be heated to a corresponding temperature, the heat energy utilization rate of a system is improved, and the accuracy of heat recovery of the system can be improved.

Embodiments of the present invention also provide a waste treatment system, as shown in fig. 2, comprising:

and the combustion device is used for carrying out combustion treatment on the dangerous waste to generate smoke. The arrows in fig. 2 indicate the direction of transfer of the flue gas.

In the technical solution provided by the present invention, preferably, the combustion apparatus includes:

and the feeding device is used for receiving solid and semi-solid dangerous waste.

The solid waste is divided into the material to be crushed and the material not to be crushed. In principle, the materials needing to be crushed do not enter the material pit, the materials needing to be crushed are put into a crusher by a bucket lifting feeder arranged outside the material pit, and the materials enter the material pit after being crushed.

The materials are not required to be crushed and directly enter the material pit, and the traveling crane is used for mixing with the crushed materials, and the mixed materials enter the furnace for incineration.

In principle, materials enter the material pit, but some materials which are not suitable for crushing and enter the material pit are put into the furnace for incineration through the stokehold bucket lifting feeder. If the part of materials are packing materials such as packaging bags and the like, the materials have large volume and small density, need to be packaged, and then are put into a stokehold hopper through a hopper lifting feeder and then are put into a furnace for incineration.

The material is through broken back, in throwing back to stokehold chain scraper conveyor hopper in unison by the driving, chain scraper conveyor sets up in stokehold feeding 12 meters platform department, adopts inverter motor drive, and the discharge end is provided with dials the material device, dials the material device and is in the same place with the chain plate, and the volume of control single entering interior material meets the requirement of burning the handling volume.

The feeding device consists of 3-level sealing doors, and is sequentially provided with a weighing hopper, a first-level sealing door, an inclined chute, a flexible connection, a second-level sealing door, a chute (with a water cooling jacket), a third-level sealing door (integrated with the front section of the chute), a casting in the furnace and the like from top to bottom.

Wherein, the hopper and one-level sealing door, oblique chute, flexible coupling, weighing module etc. constitute weighing system, the volume of the material of measurement entering stove. The chute sets up the water-cooling jacket, and the cooling water is with chute surface cooling to lower temperature, when satisfying the material whereabouts, does not say the adhesion at the material.

Be provided with the access door on the chute to one side, be convenient for clear reason block feedstock channel for packing material is bulky.

The waste liquid is stored in a warehouse, and is generally 200L iron barrel package or plastic ton barrel package. After the forklift transports the liquid waste to a waste liquid room, the liquid waste is disposed according to the same batch disposal mode of the similar materials after being tested.

The waste liquid system comprises waste liquid preparation system and waste liquid storage system, and wherein, waste liquid storage system still has the waste liquid transport function concurrently, and the pump is thrown into the combustor with the waste liquid and is gone into the stove and burn again.

The waste liquid system is divided into two flows of liquid and gas, the liquid part is completed by preparation and storage, and the waste gas part is composed of a vacuum pump, a liquid seal tank, an injection pump and the like, so that liquid phase and gas phase transfer in the waste liquid incineration process are completed together.

The waste liquid preparation system comprises a waste liquid preparation tank, a waste liquid crushing pump, a waste liquid vacuum pump and the like, and the waste liquid storage system comprises a waste liquid storage tank and a waste liquid atomizing pump.

The storage tank and the preparation tank are both provided with a steam jacket and stirring.

And the rotary kiln is connected with the feeding device, and the feeding device pours solid and semi-solid dangerous wastes into the rotary kiln.

The rotary kiln adopts a concurrent flow structure. Solid, semi-solid, liquid and other dangerous waste enter from the head of the rotary kiln, and combustion-supporting air enters from the head and is fully mixed with the dangerous waste. The tail part of the rotary kiln is slowly moved along with the rotation of the rotary kiln, and the whole process of drying, burning and burning out is finished. The slag after incineration falls into a secondary combustion chamber, and falls into a slag remover from the bottom of the secondary combustion chamber.

The slag remover adopts a water seal structure, maintains the negative pressure of the system and brings out the cooled slag. The slag falls into a slag bin, and the device is convenient to transport and store. The produced slag is periodically transported out to landfill. The smoke generated by burning enters a secondary combustion chamber from the tail part of the rotary kiln.

The operating temperature of the rotary kiln is 850 ℃ and 1000 ℃, which can reduce the carrying-out amount of particles and prolong the service life of refractory materials. The rotary kiln is controlled by variable frequency speed regulation, the rotating speed is adjustable between 0.1 and 1.1r/min, and the hazardous waste stays for 30 to 150min under the environment with the temperature of more than or equal to 850 ℃ according to the self characteristics of the hazardous waste, so that the thermal ignition loss is ensured to be less than 5 percent.

The rotary kiln hood is provided with a burner (for treating natural gas and waste liquid), a material pushing mechanism, a waste liquid spray gun interface (reserved), a combustion-supporting air inlet, an instrument interface and the like. The kiln head cover is of a self-supporting structure, so that the thrust generated by the material pushing mechanism is prevented from being transmitted to the rotary kiln. The kiln head cover is protected by refractory materials.

The rotary kiln tail cover is used for sealing the slag outlet end of the rotary kiln and guiding the smoke of the rotary kiln to the secondary combustion chamber. The junction of the kiln cylinder body and the tail cover adopts an air cooling structure, and a fan is arranged independently for ensuring the cooling effect.

The tail of the rotary kiln is provided with 1 waste liquid spray gun, and high-quality waste liquid is used as fuel for cleaning coking.

The second combustion chamber is used for further thoroughly decomposing and destroying harmful substances which are not burnt out in the flue gas generated by the primary combustion of the rotary kiln. The size of the second combustion chamber can ensure that the residence time of the flue gas is more than 2.0s at the temperature of 1100 ℃.

When an emergency shutdown condition occurs, such as power failure or water cut, the emergency chimney is started. The flue gas is discharged to the atmosphere from the top of the second combustion chamber. The top end of the quick exhaust chimney is provided with a pneumatic driving device which can be restored to the original position after each exhaust. The emergency exhaust chimney is sealed by flexible packing, so that the smoke leakage is prevented when the secondary combustion chamber operates normally.

An independent air supply fan of the second combustion chamber is arranged, so that the oxygen content of the second combustion chamber can be adjusted. For the convenience of interlocking control, 2 combined burners are arranged in the second combustion chamber, and the auxiliary fuel adopts natural gas. The two burners have different functions, the lower burner is used for burning out, and the upper burner is used for controlling temperature.

The second combustion chamber is standing equipment, is composed of a steel plate, refractory materials, heat insulation materials and the like, is vertically arranged on a steel frame, and the flue gas enters the waste heat boiler by adopting side discharge.

In order to ensure the temperature of the system during normal start-up, shutdown and normal operation, the system is matched with 3 combined burners, wherein 1 burner is positioned at the kiln head of the rotary kiln, and the other 2 burners are positioned in a secondary combustion chamber. The auxiliary fuel adopts natural gas.

The burner can be interlocked with the temperature in the furnace, and when the burning temperature reaches a set value, the burner is flamed out or the fuel injection amount is reduced; when the incineration temperature is lower, the combustor automatically adjusts and increases the fuel input amount to assist combustion.

The combustion-supporting air system comprises a primary fan of the rotary kiln and a secondary fan of a secondary combustion chamber, and the variable-frequency speed regulation is adopted.

The frequency of the combustion fan can be set according to the oxygen content in the secondary combustion chamber (measuring points are generally arranged on the waste heat boiler). When the material is stable and the operation is stable, the air quantity can be continuously and automatically adjusted.

The primary fan of the rotary kiln and the secondary fan of the secondary combustion chamber both draw combustion-supporting air from the material pit, and the discharge of VOC gas in the material pit is reduced. The primary fan is provided with multi-point internal air supply on the kiln head cover, and an internal air isolating channel is arranged in the kiln head cover.

The secondary combustion-supporting air injection wind speed of the secondary combustion chamber is 30-50m/s, a downward tangential rotational flow is formed in the furnace, and the mixing and disturbance of the flue gas in the secondary combustion chamber are intensified. A "3T + E" control method in the furnace is achieved, i.e. ensuring a sufficient Temperature of the incinerator outlet flue gas (Temperature), a sufficient residence Time of the flue gas in the combustion chamber (Time), a suitable Turbulence during combustion (Turbulence) and an excess of air (excesarir).

The high-temperature flue gas behind the secondary combustion chamber absorbs the heat of the flue gas through a waste heat utilization system, on one hand, the heat incineration device is utilized by itself, and on the other hand, the high-temperature flue gas is used for other processes in a plant area, such as materialization (if any), triple effect evaporation of sewage and plant area heating.

The waste heat system consists of a heat conduction oil furnace system and a membrane wall water-cooled boiler system.

According to the technical scheme provided by the invention, preferably, a nozzle is arranged in the rotary kiln and is used for spraying liquid dangerous waste into the rotary kiln;

And the heat conduction oil furnace is arranged at the combustion device, is communicated with the combustion device and is used for absorbing the heat of the smoke flowing through the heat conduction oil furnace to heat the heat conduction oil in the heat conduction oil furnace.

The heat conducting oil furnace system is a film-wall heat conducting oil furnace and is arranged in a first return stroke, high-temperature smoke is discharged from a second combustion chamber and then introduced into the film-wall heat conducting oil furnace through an elbow, high-quality heat conducting oil is obtained after radiation heat exchange in the furnace and is used for reheating the smoke at the back, and redundant heat is used for generating steam by a steam generator and is used in a plant area.

A denitrification reaction system is arranged at the inlet of the heat-conducting oil furnace. NOx removal is controlled by a non-catalytic method (SNCR method). The configured ammonia water solution is lifted by the atomizing pump to enter the nozzle, the nozzle is atomized by pressure and sprayed into the first return hearth of the waste heat boiler, the flue gas and the sprayed atomized ammonia water solution are fully mixed in an environment of 1100 ℃, the ammonia water is evaporated into ammonia and water vapor, NOx components in the flue gas are subjected to reduction reaction with ammonia gas in the presence of O2, and meanwhile, all water in the ammonia water solution is vaporized by the flue gas and taken away.

The membrane water wall boiler generates steam and recovers heat. The generated steam is used for internal production and external supply of the system.

The set of incineration system is provided with a demineralized water tank, a deaerator water-feeding pump, a deaerator, a boiler water-feeding pump, a steam-distributing cylinder, a pollution discharge flash tank and the like.

And the waste heat boiler is communicated with the heat conduction oil furnace and is used for absorbing the heat of the smoke of the waste heat boiler and heating the soft water in the waste heat boiler.

And the treatment device is communicated with the waste heat boiler and is used for deacidifying, dedusting and demisting the flue gas flowing through the treatment device.

In the technical solution provided by the present invention, preferably, the processing apparatus includes:

and the quenching tower is communicated with the waste heat boiler and is used for cooling the flue gas flowing through the waste heat boiler, and washing water is injected into the quenching tower.

Adopting a downstream quenching tower, and introducing high-temperature flue gas from the top of the quenching tower. The inlet of the quenching tower adopts a smoke tube for stabilizing flow, so that the smoke is uniformly distributed in the quenching tower after entering the quenching tower, thereby preventing the quenching effect from being reduced due to bias flow and preventing the salt deposition on the inner wall of the tower. A quenching lance is arranged from the top of the tower, and quenching water is rapidly atomized by compressed air.

The atomized quench water flue gas directly contacts with the flue gas, so that the temperature of the flue gas is rapidly reduced. The temperature is suddenly cooled from 550 ℃ to 195 ℃, and the temperature section can be arranged to avoid the temperature section for the dioxin resynthesis, thereby achieving the purpose of inhibiting the dioxin regeneration. Besides cooling, the flue gas also has the functions of washing and dedusting in the process of quenching.

The atomization of the quenching water is realized by a quenching pump station. The quenching pump station system comprises an atomizing pump, a spray gun, a protection fan, a water path system, a gas path system, a temperature detection system and the like.

The quenching spray gun adopts a gas-liquid two-phase nozzle to spray fine atomized water into the flue gas. The spray gun has two inputs: one path is water, and the other path is compressed air. In order to improve the running stability of the system, the quenching spray guns are arranged into 3 sets on the same layer and are mutually standby. The spray guns are all provided with protective sleeves and protective wind to prevent the flue gas from corroding the spray guns.

The quenching water adopts demineralized water, and an industrial water interface is reserved. When the demineralized water has a fault, the system can be automatically switched to the industrial water removal system to continuously supplement the quenching water. The quench water tank is provided with a large-diameter overflow pipe, and overflow water is led to a drainage point. And the problem that the quenching water overflows to the platform to pollute the environment after the water replenishing valve fails is prevented.

Adopt the demineralized water for the quench water for a long time, can cause the shower nozzle to block up, this system sets up two sets of water tanks, and one set is for containing the salt water tank, and one set is the quench water tank, and the system possesses the automatic switch-over function, contains salt water operating time and running water operating time rational ratio, and automatic switch-over uses the running water to do system self-cleaning, does not influence system's continuous operation.

And the dry deacidification tower is communicated with the quenching tower and is used for performing dry deacidification treatment on the flue gas output by the quenching tower, and slaked lime and activated carbon are injected into the dry deacidification tower.

The flue gas enters from the bottom of the deacidification tower and reacts with the sprayed lime powder to carry out deacidification. The lime powder is stored in a lime bin, the lime powder (Ca (OH)2) is continuously and uniformly sprayed into the deacidification tower through the disk feeder and the Roots blower, and the amount of the sprayed lime powder can be adjusted according to a set value. And the lime powder consumption is transmitted in real time through a weighing module arranged on a lime bin support. Ca (OH)2 and SO2, SO3, HCl, HF and the like in the flue gas are subjected to chemical reaction to generate CaSO3, CaSO4, CaCl2, CaF2 and the like. At the same time, CO2 exists in the flue gas, and a part of Ca (OH)2 is consumed to generate CaCO 3. Because a large amount of water is sprayed into the quenching tower, the water is vaporized and changed into water vapor which enters the deacidification tower along with the flue gas, and the Ca (OH)2 absorbs the moisture in the flue gas, the reaction speed is accelerated.

The lime powder is a consumable product and has a large using amount, and a mechanical feeding mode is adopted in the project. And lifting the bagged lime powder to a lime bin feeding platform through an electric hoist, starting a negative pressure feeding fan, and feeding lime to a lime bin. Reduce the dust dispersion and reduce the labor intensity.

Activated carbon powder is sprayed between the dry deacidification tower and the bag-type dust remover. The activated carbon powder is stored in the activated carbon bin and is continuously and uniformly sprayed into the flue gas pipeline through the disk feeder and the Roots blower. The amount of the sprayed activated carbon powder can be adjusted according to a set value. The consumption of the activated carbon is transmitted in real time by setting the running frequency of the activated carbon conveyor. The active carbon is strongly mixed with the flue gas, and pollutants such as dioxin, heavy metals and the like in the flue gas are adsorbed by utilizing the characteristics of the active carbon, such as large specific surface area and strong adsorption capacity.

And the bag type dust collector is communicated with the dry-method deacidification tower and is used for dedusting the flue gas output by the dry-method deacidification tower.

And the flue gas mixed with the activated carbon enters a bag type dust collector. The cloth bag material adopts PTFE + PTFE tectorial membrane, utilizes its high dust collection efficiency, gets rid of the dust granule in the flue gas. And after the dust remover reaches the design pressure difference or time interval, regularly back-blowing the cloth bag by using compressed air. The bag-type dust collector is divided into 6 chambers and adopts a step-in structure.

The design of the bag-type dust collector is in accordance with the requirements of new specifications, and no bypass is arranged.

The wet flue gas washing process adopts a two-stage washing process. Setting a first-stage deacidification tower, adjusting the temperature of the flue gas from about 180 ℃ to about 65 ℃, and entering a second-stage washing deacidification tower after reaching the optimal temperature section of acid-base reaction.

The water inlet of the first-stage deacidification tower is drained from the second-stage washing water tank, part of the water outlet of the first-stage washing water can be considered to be used for water supplement of the slag remover, and the rest of the water outlet of the first-stage washing water is used for quenching water supplement.

And the flue gas enters a secondary washing tower after passing through a primary washing tower, and the acid gas is deacidified by a wet method. The automatic detection and control of the pH values of the primary washing liquid and the secondary washing liquid can be realized in order to ensure the washing effect of the alkali liquor added into the secondary washing tower. The control system automatically adjusts the dosage according to the change of the PH value, so that the PH value of the washing water is kept in the optimal range, and the influence of human factors on the wet washing effect is overcome. The temperature of the flue gas is reduced to about 60 ℃ after passing through the secondary washing tower.

The second-stage washing tower is a sieve plate tower and is made of FRP materials. The FRP material has good corrosion resistance and fatigue resistance, and can be used for a long time in acid, alkali, chloride salt and humid environments. Meanwhile, the corrosion of the PH value of the washing water to equipment caused by peracid due to fluctuation of working conditions can be avoided. The flue gas is in a divergent shape after entering the second-stage washing tower, and continuously vertically passes through each layer of sieve plate upwards, and the acidic gas reacts with washing water when passing through the sieve plate, so that the acidic gas is removed. Through the water distribution device of special design and the nozzle of preventing blockking up the design, evenly arrange the washing water in the sieve top, guarantee that the washing water spreads to whole tower cross-section, can both fully contact with the washing water when guaranteeing all flue gases to pass through each layer sieve.

And a demister is arranged at the outlet of the secondary washing tower, and liquid drops can be removed from the flue gas flow through the demister. The demister is provided with a washing nozzle and can intermittently and automatically spray high-pressure cleaning water to clean the demister. Separating out the substances such as salt, fly ash and the like precipitated on the water, and conveying the substances into washing water to a washing water tank.

The washing water flows out of the washing tower and then enters the washing water tank by means of gravity, a PH value monitor is arranged at the outlet of the washing pump, the frequency of the alkali liquor feeding pump is adjusted by the PH value, and then the washing water is pumped into the washing tower for recycling. Periodically draining part of the washing water to the pre-cooling water tank, and simultaneously replenishing new washing water to maintain the liquid level of the washing water tank.

Because the moisture content in the flue gas is higher after the wet washing, white smoke plume is generated if the flue gas is directly discharged through a chimney, and the visual effect is poor. In order to avoid the generation of smoke plume, the wet electrostatic precipitator is used for reducing the water content in the smoke and reducing the smoke plume.

The wet electrostatic precipitator is vertical square equipment, an internal electric field adopts a regular hexagon honeycomb tube as an anode, and a cathode wire adopts a lead-antimony alloy barbed wire.

The wet electrostatic precipitator is made of FRP.

According to the technical scheme provided by the invention, preferably, the bag type dust collector is connected with a fly ash storage bin, and the fly ash storage bin is used for treating dust collected by the bag type dust collector.

The GGH heat exchanger comprises a GGH heating structure and a GGH flowing structure, wherein the GGH flowing structure is communicated with the processing device, so that flue gas output by the waste heat boiler flows to the GGH flowing structure.

The flue gas heater comprises a flue gas heating structure and a flue gas flowing structure, wherein the flue gas heating structure is communicated with the heat-conducting oil furnace, the flue gas flowing structure is communicated with the GGH flowing structure, and heat-conducting oil in the flue gas heating structure heats flue gas in the GGH heat exchanger.

And the catalytic device is communicated with the flue gas flowing structure and is used for carrying out catalytic treatment on the flue gas output by the flue gas flowing structure.

And the catalytic device is communicated with the GGH heating structure and is used for enabling the catalyzed flue gas to flow into the GGH heating structure.

And the purified flue gas finally enters a chimney through a draught fan to be discharged. The chimney is provided with a set of smoke on-line detection device for detecting data such as smoke dust, SO2, CO, NOx, HCl and O2 in the smoke discharged by burning, and meanwhile, adjustment reference is provided for the operation condition.

In order to meet the working requirement of SCR and the requirement of smoke whitening, the system is provided with a GGH heat exchanger and a heat-conducting oil smoke reheater.

The GGH heat exchanger is used for recovering flue gas heat, recovering high-temperature flue gas heat after SCR, and increasing the flue gas temperature after wet process.

And the heat conduction oil heat exchanger is used for further heating the low-temperature flue gas heated by the GGH heat exchanger so as to meet the requirement of SCR working temperature. The system is provided with SCR for thoroughly solving the emission of NOx in the flue gas. SCR is catalytic reaction, and the invention is provided with 3 layers of catalytic reaction beds.

According to the technical scheme provided by the invention, preferably, the catalytic device comprises a mixer and an SCR + dioxin catalytic reaction tower which are sequentially connected;

and transferring the catalyzed flue gas to a GGH heating structure.

The main sources of the ash in the invention are incineration slag, fly ash generated by a waste heat boiler, a quench tower, a dry deacidification tower, a bag-type dust remover and the like.

The residue of the rotary kiln falls from the kiln tail and the secondary combustion chamber enters a water-seal scraper slag remover, is conveyed out by the scraper slag remover after water quenching, and is directly buried after being detected to be qualified.

The monitoring and control of the system adopts a DCS control system and has the communication function with a plant-level computer management system. The operation monitoring of the system is completed in the control room.

A system operator station, an engineer station and a laser recording printer are arranged in the control room.

And an operator monitors and controls the system through a keyboard and a mouse in the incineration control room. The control room is not provided with a conventional instrument control dial.

The control system is provided with an 11KVA single-in single-out online UPS device, and is automatically switched to a storage battery pack for power supply on line when power supply is lost, so that misoperation of a valve is avoided, and system data are not lost. The UPS power supply device is provided with a storage battery pack and has a fault bypass function, and the capacity of the storage battery pack can ensure that the whole set of control system continuously and normally works for no less than 30 minutes after the UPS device loses an external power supply.

The central control room is provided with a color digital industrial television system, the rotary kiln and the secondary combustion chamber are respectively provided with a set of peeping type high-temperature hearth flame monitoring video loop, and monitoring points are arranged in a waste storage room, a feeding area, a boiler, the rotary kiln and the like to monitor the operation condition of the system.

The whole electric and automatic control system can realize the following functions:

1) all motors can carry out button start-stop operation in a local state and upper computer mouse start-stop operation and remote control in a remote state; and starting and stopping operation and remote control of the upper computer of the electromagnetic regulating valve.

2) Automatic bucket lifting type feeding control, spiral feeding automatic control and automatic chain plate type feeding control.

3) The rotary kiln combustor is automatically ignited, automatically supplied with air and automatically controlled in temperature.

4) The automatic ignition, the automatic air supply regulation and the automatic control of the temperature of the second combustion chamber are carried out on the second combustion chamber burner.

5) PID automatic regulation control and manual frequency setting control of an induced draft fan, a rotary kiln blower, a secondary combustion chamber blower and a quench tower atomizing pump; controlling the rotation speed of the kiln body; quench tower feedwater regulation, heater steam control valves, and the like.

6) And a system instrument operation parameter monitoring system.

7) The parameters of the on-line monitoring system (first supply) are transmitted in real time, and the parameters are displayed by the upper computer in real time.

8) The upper computer monitors on line in real time, and realizes the functions of main process display, shunt process display, real-time parameter display of operation, data archiving, report and trend query, alarm display, parameter modification, electrical equipment control, printout and the like.

9) Video monitoring is set for important equipment and workshop sections of the incineration system, and video monitoring for main equipment areas and workshop sections is realized in a control room through a wall-mounted liquid crystal television.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of heat recovery suitable for waste treatment, comprising:

60-80 ℃ of flue gas is heated to 170-190 ℃ through the GGH heat exchanger;

2. The heat recovery method for waste disposal according to claim 1,

a heat conduction oil exchanger is arranged in the heat conduction oil furnace, and heat conduction oil is arranged in the heat conduction oil exchanger in advance;

3. The heat recovery method for waste disposal according to claim 1,

a GGH heating structure and a GGH flowing structure are arranged in the GGH heat exchanger;

enabling 60-80 degrees of flue gas to flow through the GGH flow structure;

4. A waste treatment system, comprising:

5. The waste treatment system of claim 4,

the combustion apparatus includes:

a feed device for receiving solid, semi-solid hazardous waste;

6. The waste treatment system of claim 5,

a nozzle is arranged in the rotary kiln and used for spraying liquid dangerous waste into the rotary kiln;

7. The waste treatment system of claim 4,

the processing device comprises:

8. The waste treatment system of claim 7,

the bag-type dust collector is connected with a fly ash storage bin, and the fly ash storage bin is used for processing dust collected by the bag-type dust collector.

9. The waste treatment system of claim 7,

the catalytic device comprises a mixer and an SCR + dioxin catalytic reaction tower which are connected in sequence;

and transferring the catalyzed flue gas to a GGH heating structure.

10. The waste treatment system of claim 7,

the GGH heating structure comprises a first heating channel and a first heated channel, wherein flue gas with the temperature of 230-240 ℃ flows through the first heating channel, and flue gas with the temperature of 60-80 ℃ flows through the first heated channel;

the regulated gas flow is obtained by the following formula,