CN114440222A

CN114440222A - Organic solid waste pyrolysis system and method

Info

Publication number: CN114440222A
Application number: CN202210122209.XA
Authority: CN
Inventors: 程文丰; 茹斌; 戴贡鑫; 徐月亭; 郭泗勇; 曾志伟; 宛政; 孙立
Original assignee: Shanghai Electric Group Corp
Current assignee: Shanghai Electric Group Corp
Priority date: 2022-02-09
Filing date: 2022-02-09
Publication date: 2022-05-06

Abstract

The invention discloses an organic solid waste pyrolysis system and method. The system comprises a feeding subsystem, a pyrolysis subsystem and a pyrolysis gas purification subsystem which are connected in sequence; the feeding subsystem comprises a feeding pipe; the pyrolysis subsystem comprises a dividing wall rotary kiln, an in-kiln burner and a non-condensable gas incinerator; the dividing wall rotary kiln comprises a feed inlet, a pyrolysis gas outlet, a jacket flue gas inlet and a jacket flue gas outlet; the pyrolysis gas outlet is connected with the inlet of the pyrolysis gas purification subsystem and is used for purifying the pyrolysis gas to obtain non-condensable gas; the pyrolysis gas purification subsystem is connected with the in-kiln burner through a first non-condensable gas conveying pipeline and provides non-condensable gas for the combustion of the in-kiln burner; the pyrolysis gas purification subsystem is connected with an inlet of the non-condensable gas incinerator through a second non-condensable gas conveying pipeline and is used for generating flue gas; the first outlet of the non-condensable gas incinerator is connected with the flue gas inlet of the jacket. The system has high heat exchange efficiency and safe and stable operation.

Description

Organic solid waste pyrolysis system and method

Technical Field

The invention relates to an organic solid waste pyrolysis system and method.

Background

In the treatment method of organic solid wastes (such as domestic garbage, agriculture and forestry biomass and the like, which contain a certain amount of organic matter components, have low calorific value and can mostly realize self-sustaining combustion), the pyrolysis technology taking oxygen deficiency or even oxygen-free as the treatment condition can remove and thermally crack the organic components in the raw materials to achieve the aims of reduction and harmlessness, and meanwhile, the minimum treatment scale requirement of a power station steam turbine on an incineration line is not required, so that the method has the characteristic of more flexible scale and can be suitable for different demand scenes within 5 t/d-200 t/d. However, the current pyrolysis technology still has some disadvantages.

For example, patent document CN111635773A discloses a system and a method for pyrolysis and gasification of organic solid wastes, which have the following problems:

(1) the combustion chamber is arranged at the tail part of the rotary gasification kiln, part of pyrolysis gas produced by the rotary kiln is sent back to the combustion chamber for incineration, and high-temperature flue gas generated by the incineration of the part of pyrolysis gas is used as a heat source, enters the rotary gasification kiln through a high-temperature dust removal net and is in direct contact with materials, so that the convection heat exchange is realized. The intensity of convective heat exchange and dividing wall type heat exchange of high-temperature flue gas and materials is not as strong as that of radiant heat exchange, so that the diameter and the length of a kiln body are usually large by adopting a convective heat exchange or dividing wall type heat conduction rotary kiln, and the actual filling degree of the materials is very low, usually 5% -8%.

(2) The system needs to provide excessive high-temperature flue gas for heat exchange with materials, and the pyrolysis gas generated by the materials can be mixed with inert components in the flue gas, so that the heat value of the mixed gas is reduced. Along with the increase of the circulation times, the heat value of the pyrolysis gas generated by the rotary gasification kiln gradually tends to be balanced. Therefore, the system cannot treat materials with low heat value (such as industrial waste salt containing organic matters, unsorted household garbage and sludge and oil sludge with high water content) or large heat value fluctuation (such as various dangerous waste mixtures in an industrial park), and even the stable operation can be ensured only by blending raw materials with coal or afterburning in a combustion chamber.

For another example, patent document CN204829926U discloses a household garbage classification gasification system for rotary kiln gasification and plasma melting, which uses high-temperature gas generated by a melting furnace as an external heat source for pyrolysis gasification, and recovers heat of synthesis gas to improve system thermal efficiency. The rotary kiln type pyrolysis gasifier carries out pyrolysis reaction by convective heat exchange between high-temperature synthesis gas and materials, and has the problems of low heat exchange efficiency, large equipment size and low material filling rate in patent document CN 111635773A.

In summary, the thermal cracking technology of organic solid wastes in the prior art needs to improve the heat exchange efficiency of the pyrolysis reactor.

Disclosure of Invention

The invention provides an organic solid waste pyrolysis system and method for solving the problem that the heat exchange efficiency of a dividing wall rotary kiln is low in the organic solid waste pyrolysis technology in the prior art. The dividing wall rotary kiln combines the radiation heat exchange in the kiln and the dividing wall type heat exchange of the cylinder body, the heat exchange efficiency is high, and the operation of a pyrolysis reaction system is safe and stable.

The invention solves the technical problems through the following technical scheme.

The invention provides an organic solid waste pyrolysis system, which comprises a feeding subsystem, a pyrolysis subsystem and a pyrolysis gas purification subsystem which are sequentially connected;

the feed subsystem comprises a feed pipe;

the pyrolysis subsystem comprises a dividing wall rotary kiln, an in-kiln burner and a non-condensable gas incinerator;

the dividing wall rotary kiln comprises a feed inlet, a pyrolysis gas outlet, a jacket flue gas inlet and a jacket flue gas outlet;

the feeding pipe is arranged through the feeding hole, and an outlet of the feeding pipe is positioned inside the dividing wall rotary kiln;

the in-kiln burner is arranged at the kiln head of the dividing wall rotary kiln;

the pyrolysis gas outlet is connected with the inlet of the pyrolysis gas purification subsystem and is used for purifying the pyrolysis gas to obtain non-condensable gas;

the pyrolysis gas purification subsystem is connected with the in-kiln burner through a first non-condensable gas conveying pipeline and provides non-condensable gas for combustion of the in-kiln burner; the pyrolysis gas purification subsystem is connected with an inlet of the non-condensable gas incinerator through a second non-condensable gas conveying pipeline and is used for generating flue gas;

the first outlet of the non-condensable gas incinerator is connected with the jacket flue gas inlet;

the jacket flue gas inlet and the jacket flue gas outlet are respectively arranged at two ends of an outer jacket of the dividing wall rotary kiln.

In the invention, the in-kiln burner burns the pyrolysis non-condensable gas in the dividing wall rotary kiln, and the flame generated by burning provides part of heat required by the pyrolysis of the raw material in a radiation heat exchange mode. And a first outlet of the non-condensable gas incinerator is connected with the jacket flue gas inlet, and high-temperature flue gas obtained by incineration is used for heat exchange of the dividing wall rotary kiln. Therefore, the heat exchange of the radiation in the kiln and the heat exchange of the dividing wall of the outer jacket meet the total heat required by the pyrolysis of the raw materials together.

In the present invention, preferably, the feeding subsystem further comprises a raw material storage tank and a raw material conveying device. The raw material storage tank is used for storing the dried raw materials.

Wherein, preferably, the raw material conveying equipment comprises a grab bucket crane and a storage bin. The grab crane conveys the raw materials in the raw material storage tank to the storage bin, an outlet at the bottom of the storage bin is connected with an inlet pipeline of the feeding pipe, and the raw materials are conveyed to the feeding pipe.

In the present invention, preferably, a hydraulic plunger pump and a piston rod are further disposed in the pipeline of the feeding pipe. The piston push rod in the feeding pipe is driven by the hydraulic plunger pump, the raw materials are compressed in the feeding pipe under the extrusion force, air in a gap of the raw materials is discharged, and the phenomenon that the non-quantifiable external air enters a downstream pyrolysis subsystem along with the raw materials is reduced; meanwhile, the compressed raw materials form a material plug, and the back-flow of high-temperature gas in the pyrolysis subsystem operating under micro-positive pressure to the feeding pipe is prevented.

In the present invention, as known to those skilled in the art, the two ends of the dividing wall rotary kiln can be referred to as the kiln head and the kiln tail, respectively, and the feed inlet of the dividing wall rotary kiln is generally arranged at the kiln head.

In the invention, preferably, a kiln head sealing cover is arranged at one end of the dividing wall rotary kiln close to the kiln head, and the kiln head sealing cover is rotatably connected with the dividing wall rotary kiln to form dynamic and static sealing.

Preferably, the in-kiln burner is fixed in the kiln head sealing cover.

Wherein, preferably, the feeding pipe is fixed in the kiln head sealing cover.

Preferably, the feeding pipe is positioned above the in-kiln burner, the feeding pipe is externally tangent to the in-kiln burner, and the feeding pipe and the in-kiln burner are internally tangent to the kiln head sealing cover respectively; the circle center of the feeding pipe, the circle center of the burner in the kiln and the circle center of the dividing wall rotary kiln are positioned on the same straight line. Therefore, a connecting line of the circle centers of the feeding pipe and the in-kiln burner is perpendicular to a material stacking surface (as shown in fig. 2, namely the angle a + the angle b is 90 degrees), and the in-kiln burner is positioned between the feeding pipe and the material. According to the dynamic stacking angle of the materials in the kiln body, the angle between the feeding pipe and the burner in the kiln is determined, and the radiation heat exchange effect is optimized.

In the invention, preferably, the kiln head is of a throat structure so as to reduce the dynamic and static sealing area.

In the invention, preferably, the kiln tail of the dividing wall rotary kiln is of a straight-tube structure, and a kiln tail sealing cover of the dividing wall rotary kiln is rotatably connected with the dividing wall rotary kiln to form dynamic and static sealing.

In the invention, preferably, the dividing wall rotary kiln further comprises a material outlet; the material outlet is positioned below the kiln tail of the dividing wall rotary kiln and used for recovering materials pyrolyzed by the dividing wall rotary kiln.

In the invention, preferably, the kiln tail sealing cover of the partition wall rotary kiln is further provided with a first pyrolysis gas thermometer and a pyrolysis gas pressure gauge.

In the present invention, preferably, the pyrolysis subsystem further includes a first flue gas branch, a second flue gas branch and a flue gas main line;

the jacket flue gas outlet is connected with the inlet of the first flue gas branch; and a second outlet of the non-condensable gas incinerator is connected with an inlet of the second flue gas branch, and the first flue gas branch and the second flue gas branch are converged into the flue gas main path.

Preferably, the outlet of the flue gas main path is sequentially connected with the raw material drying unit and the flue gas purification unit.

Preferably, a first flow regulating valve is arranged on the first flue gas branch, a second flow regulating valve is arranged on the second flue gas branch, and the first flow regulating valve and the second flow regulating valve are used for regulating the proportion of the flue gas flow distributed to the outer jacket of the dividing wall rotary kiln and the flue gas flow of the second flue gas branch.

Preferably, a first flue gas thermometer is arranged in a pipeline connecting the first outlet of the non-condensable gas incinerator and the jacket flue gas inlet, and a second flue gas thermometer is further arranged on the first flue gas branch.

In the invention, the pyrolysis subsystem further comprises a noncondensable gas main pipeline, an emptying pipe and a natural gas pipeline; an inlet of the non-condensable gas main pipeline is connected with the pyrolysis gas purification subsystem, an outlet of the non-condensable gas main pipeline is respectively connected with the first non-condensable gas conveying pipeline and the second non-condensable gas conveying pipeline, and a non-condensable gas induced draft fan, a first shut-off valve, an evacuation port and a natural gas inlet are arranged on the non-condensable gas main pipeline; an inlet of the emptying pipe is connected with an emptying port of the non-condensable gas main pipeline, and a second shut-off valve is arranged on the emptying pipe; the outlet of the natural gas pipeline is connected with the natural gas inlet, and the natural gas inlet is positioned in the downstream pipeline of the first shutoff valve.

Preferably, a third flow regulating valve and a first non-condensable gas flow meter are arranged in the first non-condensable gas conveying pipeline.

Preferably, a fourth flow regulating valve and a second non-condensable gas flowmeter are arranged in the second non-condensable gas conveying pipeline.

Preferably, a third shut-off valve is arranged on the natural gas pipeline and used for switching in or cutting off natural gas to be introduced.

Preferably, the outlet of the non-condensable gas induced draft fan is also provided with a non-condensable gas analyzer. In a preferred embodiment, the non-condensable gas analyzer can detect information such as a calorific value and an oxygen content of the non-condensable gas.

Preferably, the pyrolysis subsystem further comprises a non-condensable gas inlet pressure regulating valve and a non-condensable gas thermometer, and the non-condensable gas inlet pressure regulating valve and the non-condensable gas thermometer are arranged in a pipeline connected with the non-condensable gas induced draft fan and the pyrolysis gas purification subsystem. In a preferred embodiment, the pressure of the pyrolysis gas pressure gauge can be controlled by adjusting the non-condensable gas inlet pressure adjusting valve through piezoresistive throttling, the micro-positive pressure operation of the dividing wall rotary kiln is maintained, and the non-condensable gas temperature reduction and tar removal conditions can be monitored by using the non-condensable gas thermometer.

In the present invention, preferably, the pyrolysis subsystem further comprises a blower for providing air and/or oxygen to the pyrolysis subsystem; and a first outlet pipeline of the air feeder is connected with the in-kiln burner, and a second outlet pipeline of the air feeder is connected with an inlet of the non-condensable gas incinerator.

Preferably, a first oxidant flow meter and a fifth flow regulating valve are arranged on a first outlet pipeline of the blower; and a second oxidant flowmeter and a sixth flow regulating valve are arranged on a second outlet pipeline of the blower. In a preferred embodiment, the fifth flow regulating valve and the third flow regulating valve are controlled to enable the air coefficient in the dividing wall rotary kiln to be about 0.7, so that micro-anoxic combustion of a combustor in the kiln is realized, and unreacted oxygen is prevented from being mixed into high-temperature pyrolysis gas; in addition, the sixth flow regulating valve and the fourth flow regulating valve can be controlled to ensure that the temperature of the flue gas at the outlet of the non-condensable gas incinerator is about 650 ℃, so that the overtemperature of the pipeline and the cylinder of the dividing wall rotary kiln can be prevented.

In the present invention, preferably, the pyrolysis gas purification subsystem includes a spray tower, an inlet of the spray tower is connected to the pyrolysis gas outlet, and a non-condensable gas outlet pipeline of the spray tower is connected to the first non-condensable gas delivery pipeline and the second non-condensable gas delivery pipeline, respectively. In a preferred embodiment, the non-condensable gas outlet pipeline of the spray tower is connected to the non-condensable gas main pipeline and then is respectively connected to the first non-condensable gas conveying pipeline and the second non-condensable gas conveying pipeline.

Preferably, a second pyrolysis gas thermometer is arranged in a pipeline connecting the inlet of the spray tower and the pyrolysis gas outlet.

Preferably, a liquid outlet of the spray tower is connected with an oil-water separation tank, and the oil-water separation tank is positioned below the spray tower and used for oil-water separation.

Preferably, a water phase outlet of the oil-water separation tank is connected with a spray water cooling unit; and an oil phase outlet of the oil-water separation tank is connected with the tar treatment unit, or the oil phase outlet of the oil-water separation tank is connected with an inlet of the non-condensable gas incinerator. The spray water cooling unit can adopt closed air cooling.

Preferably, the water phase outlet of the oil-water separation tank is sequentially connected with the spray water cooling unit and the spray tower, so that the spray water of the spray tower can be recycled.

More preferably, the spray water cooling unit is further connected with the atomized water pipeline of the discharge subsystem.

Preferably, a spray pump and a spray water quantity regulating valve are further arranged in a pipeline connecting the spray water cooling unit and the spray tower.

In the invention, preferably, the organic solid waste pyrolysis system further comprises a discharging subsystem; the discharging subsystem is connected with a material outlet of the dividing wall rotary kiln.

Wherein, preferably, the discharging subsystem comprises a closed slag scraper and a product storage tank which are connected in sequence.

Preferably, the closed slag tapping scraper is provided with a plurality of atomizing water nozzles along the advancing direction of the pyrolysis residual carbon. Preferably, the discharging subsystem further comprises an atomized water pipeline, and a plurality of atomized water nozzles are arranged on the atomized water pipeline; the export of closed slag scraper is equipped with the row of burnt thermometer better, be equipped with the atomized water governing valve on the atomized water pipeline to adjust the volume of spraying, make the temperature that row burnt thermometer measured maintain 150 ~ 200 ℃, realize the semi-dry quenching of pyrolysis carbon residue. The discharging subsystem adopts a closed semi-dry quenching process, so that the air tightness of the system is increased, the reutilization property of slag discharge is improved, and no wastewater is generated. In a preferred embodiment, the inlet of the atomized water pipeline is connected with the first atomized water outlet of the pyrolysis gas purification subsystem.

Preferably, a fourth shutoff valve is arranged in an outlet pipeline of the closed slag tapping scraper conveyor, and a fifth shutoff valve is arranged in an outlet pipeline of the product storage tank.

Preferably, the outlet of the product storage tank is connected with a pyrolysis residue treatment unit, the pyrolysis residue is sent to the pyrolysis residue treatment unit, and the recyclable metal is separated and then subjected to harmless treatment, such as sanitary landfill, direct incineration or gasification raw material.

The invention also provides an organic solid waste pyrolysis method which is carried out by adopting the organic solid waste pyrolysis system and comprises the following steps:

conveying organic solid wastes to the partition wall rotary kiln through the feeding pipe, and burning the organic solid wastes through a combustor in the kiln to obtain pyrolysis gas;

conveying the pyrolysis gas to the pyrolysis gas purification subsystem, and purifying the pyrolysis gas to obtain non-condensable gas;

dividing the non-condensable gas into at least two parts, and conveying one part of the non-condensable gas to the in-kiln combustor to provide the non-condensable gas for the combustion of the in-kiln combustor; conveying a part of the non-condensable gas to the non-condensable gas incinerator, and obtaining flue gas through incineration;

and conveying the flue gas to an outer jacket of the dividing wall rotary kiln to provide heat for the dividing wall rotary kiln.

In a preferred embodiment of the present invention, the starting of the organic solid waste pyrolysis system comprises: a dividing wall rotary kiln starting step, a noncondensable gas incinerator starting step, an oxygen replacement step in the dividing wall rotary kiln, a load increasing and adjusting step, a step of replacing natural gas with noncondensable gas and a system dynamic balancing step;

the partition wall rotary kiln starting step comprises the following steps:

s1.1, in a system cold state, the dividing wall rotary kiln starts to rotate at a low speed, positioning scaleplates of a kiln head and a kiln tail of the dividing wall rotary kiln are checked in the rotating process, and whether the radial run-out and the axial positioning of a kiln body of the dividing wall rotary kiln meet the sealing requirements of a kiln head sealing cover and a kiln tail sealing cover or not is determined;

s1.2, gradually increasing the rotating speed of the dividing wall rotary kiln to a rated rotating speed, and checking the rotation and jumping conditions of a kiln body of the dividing wall rotary kiln;

the rotating speed of the low-speed rotation is generally 5-25% of the rated rotating speed, which is known to a person skilled in the art;

the starting step of the non-condensable gas incinerator comprises the following steps:

s2.1, starting a spray tower, a spray water cooling unit and a spray pump;

s2.2, opening a second shut-off valve, closing the first shut-off valve, starting a non-condensable gas induced draft fan, and adjusting the opening of a non-condensable gas inlet pressure adjusting valve to enable the thermal pyrolysis gas pressure gauge to display micro-negative pressure;

s2.3, opening a third shut-off valve, opening a blower, and coordinately controlling the valve openings of a third flow regulating valve, a fifth flow regulating valve, a fourth flow regulating valve and a sixth flow regulating valve to ensure that the in-kiln combustor burns in a micro-anoxic mode (namely the excess air coefficient is less than 1) and the non-condensable gas incinerator burns normally (namely the excess air coefficient is greater than 1); preheating a kiln body of the dividing wall rotary kiln through a non-condensable gas incinerator and an in-kiln burner, and replacing air in the dividing wall rotary kiln with flue gas;

s2.4, adjusting the opening of a non-condensable gas inlet pressure adjusting valve, and keeping a pyrolysis gas pressure gauge to display micro negative pressure so as to maintain the stability of the micro negative pressure in a kiln body of the dividing wall rotary kiln;

the oxygen replacement step in the partition wall rotary kiln comprises the following steps:

s3.1, adjusting the opening of a non-condensable gas inlet pressure adjusting valve, and keeping a pyrolysis gas pressure gauge to display micro-positive pressure;

s3.2, keeping the combustor in the kiln to be stable in a micro-anoxic combustion state, and observing that the oxygen concentration measured by a non-condensable gas analyzer is gradually reduced to a safety range (less than or equal to 0.5% Vol.) from 21% (namely the oxygen concentration in the air); until the oxygen replacement in the dividing wall rotary kiln and a pyrolysis gas pipeline thereof is complete;

the load increasing and adjusting step comprises the following steps:

s4.1, taking a second pyrolysis gas thermometer as a pyrolysis gas pipeline preheating degree judgment index to prevent the pyrolysis gas from being condensed and blocked in the pipeline due to low temperature;

s4.2, starting a hydraulic plunger pump, starting feeding with a small load (30% -50%), and observing the pressure change condition of an oil hydraulic cylinder of the hydraulic plunger pump (reflecting the extrusion condition of the material in the feeding pipe and the formed material plug shape) in the feeding process; simultaneously adjusting the air quantity of a non-condensable gas induced draft fan and the opening of a non-condensable gas inlet pressure adjusting valve, and keeping a pyrolysis gas pressure gauge to display micro-positive pressure;

s4.3, gradually increasing the load until the load reaches 100%;

the step of replacing natural gas with non-condensable gas comprises the following steps:

s5.1, observing the form of pyrolysis residues discharged by the discharging subsystem, and judging whether the materials are pyrolyzed sufficiently or not; judging whether the quality of the non-condensable gas reaches the standard (namely judging whether the stable combustion requirement is met) according to the heat value measured by the non-condensable gas fuel gas analyzer;

s5.2, opening the first shut-off valve, closing the second shut-off valve, and conveying the non-condensable gas into a non-condensable gas main pipeline; gradually reducing the opening degree of the third shut-off valve until the third shut-off valve is completely closed, so that the natural gas is completely cut off; simultaneously adjusting the air volume of the air feeder and the opening degrees of a fifth flow regulating valve and a sixth flow regulating valve, and keeping the micro-anoxic combustion of the in-kiln combustor and the normal combustion of the non-condensable gas incinerator;

the system dynamic balancing step comprises:

s6.1, analyzing the properties of the pyrolysis residues, and observing the conditions of existence of intergrowth and the like;

s6.2, observing measurement results of a first pyrolysis gas thermometer (whether the pyrolysis gas temperature reaches the standard), a pyrolysis gas pressure gauge (whether the dividing wall rotary kiln operates in a stable micro-positive pressure mode), a non-condensable gas thermometer (whether a spray tower works normally), a non-condensable gas analyzer (whether the non-condensable gas heat value and the oxygen concentration level reach the standard), a first smoke thermometer and a second smoke thermometer (whether smoke in an outer jacket of the dividing wall rotary kiln provides sufficient heat), and indicating that the system operates stably if the set target is reached.

In a preferred embodiment of the present invention, the treatment steps of the organic solid waste pyrolysis system for the noncondensable gas with low calorific value or excessive oxygen content include: the method comprises the steps of natural gas replacing noncondensable gas, load reduction and adjustment, oxygen replacement in a dividing wall rotary kiln, load increase and adjustment, natural gas replacing by noncondensable gas and system dynamic balance;

the step of replacing the non-condensable gas by the natural gas comprises the following steps:

s1.1, slowly opening the opening degree of a third shut-off valve, conveying a small amount of natural gas to a noncondensable gas main pipeline, and improving the heat value of the noncondensable gas so as to keep the combustion stability of the in-kiln combustor and the noncondensable gas incinerator;

s1.2, in the process of opening the opening degree of the third shut-off valve, slowly increasing the opening degree of the second shut-off valve and reducing the opening degree of the first shut-off valve until the third shut-off valve and the second shut-off valve are completely opened and the first shut-off valve is closed; in the process, the in-kiln burner is maintained to burn under the condition of micro-hypoxia, the non-condensable gas incinerator burns normally, and the micro-positive pressure is displayed by a pyrolysis gas pressure gauge;

the load reduction step comprises:

s2.1, reducing the material pushing frequency of a hydraulic plunger pump, reducing the feeding amount to a small load (30% -50%), observing the pressure change conditions of an oil hydraulic cylinder of the hydraulic plunger pump and a pyrolysis gas pressure gauge in the process, and maintaining the material plug sealing of a feeding pipe and the operation of the partition wall rotary kiln under the micro-positive pressure condition;

s2.2, reducing the air volume of the air feeder, reducing the opening degree of a third shut-off valve and reducing the natural gas flow; so as to reduce the thermal power of the in-kiln burner and the non-condensable gas incinerator;

s3.2, keeping the combustor in the kiln to be stable in a micro-anoxic combustion state, and observing that the oxygen concentration measured by the non-condensable gas analyzer is gradually reduced to a safety range (less than or equal to 0.5% Vol.); until the oxygen replacement in the dividing wall rotary kiln and a pyrolysis gas pipeline thereof is complete;

the load increasing and adjusting step comprises the following steps:

s4.1, taking a second pyrolysis gas thermometer as a pyrolysis gas pipeline preheating degree judgment index to prevent pyrolysis gas from being condensed and blocked in a pipeline due to low temperature;

s4.3, gradually increasing the load until the load reaches 100%;

the system dynamic balancing step comprises:

s6.1, analyzing the property of the pyrolysis residue, and observing whether the pyrolysis residue exists or not;

In a preferred embodiment of the present invention, the blowing out of the organic solid waste pyrolysis system comprises: a step of replacing non-condensable gas with natural gas, a step of load reduction and adjustment, a step of cutting off the natural gas and a step of shutting down a dividing wall rotary kiln;

the step of replacing the non-condensable gas by natural gas comprises the following steps:

the load reduction step comprises:

s2.1, stopping the pushing and feeding action of the hydraulic plunger pump;

s2.2, continuously operating the dividing wall rotary kiln at a rated rotating speed until all materials in the dividing wall rotary kiln are discharged;

the natural gas cutting step comprises:

s3, closing the third flow regulating valve and the third shutoff valve, closing the air feeder, and closing the in-kiln burner;

the shutdown step of the dividing wall rotary kiln comprises the following steps:

s4.1, observing that the gas calorific value detected by the noncondensable gas analyzer is reduced to 0, namely after all combustible gas components in the dividing wall rotary kiln and a pipeline thereof are completely replaced, starting a blower, starting a fifth flow regulating valve to convey external cold air from the kiln internal burner into the dividing wall rotary kiln, observing that the oxygen concentration detected by the noncondensable gas analyzer is recovered to 21 percent, indicating that the smoke in the kiln body is completely replaced, and then closing the blower;

and S4.2, reducing the rotating speed of the dividing wall rotary kiln until the dividing wall rotary kiln is reduced to a safe shutdown temperature, and then closing the dividing wall rotary kiln.

On the basis of the common knowledge in the field, the above preferred conditions can be combined randomly to obtain the preferred embodiments of the invention.

The reagents and starting materials used in the present invention are commercially available.

The positive progress effects of the invention are as follows:

the dividing wall rotary kiln combines the radiation heat exchange in the kiln and the dividing wall type heat exchange of the cylinder body, the heat exchange efficiency is high, and the operation of a pyrolysis reaction system is safe and stable. The organic solid waste pyrolysis system can realize safe and stable operation of the system, and can be widely applied to treatment of municipal domestic waste, oily sludge, hazardous waste salt and the like.

Drawings

Fig. 1 is a schematic view of an organic solid waste pyrolysis system of example 1.

FIG. 2 is a schematic cross-sectional view of the burner and feed tube in the kiln of example 1.

FIG. 3 is a schematic representation of the burner and feed tube in the kiln of example 1.

Fig. 4 is a flowchart of the start-up procedure of the organic solid waste pyrolysis system of example 1.

FIG. 5 is a flow chart of the processing steps of the organic solid waste pyrolysis system of example 1 for low heating value or excessive oxygen content of the non-condensable gases.

FIG. 6 is a schematic view of the blowing out step of the organic solid waste pyrolysis system of the embodiment.

Description of the reference numerals

Feed subsystem 1

Feed pipe 101

Piston push rod 102

Grab bucket crane 103

Stock bin 104

Hydraulic plunger pump 105

Pyrolysis subsystem 2

Dividing wall rotary kiln 201

Feed inlet 202

In-kiln burner 203

Non-condensable gas incinerator 204

Pyrolysis gas outlet 205

Jacket flue gas inlet 206

Jacket flue gas outlet 207

Kiln head 208

Kiln tail 209

Kiln head sealing cover 210

Material outlet 211

First pyrolysis gas thermometer 212

Pyrolysis gas pressure gauge 213

First flue gas branch 214

Second flue gas branch 215

Flue gas main 216

Raw material drying unit 217

Flue gas cleaning unit 218

First flow rate regulating valve 219

Second flow regulating valve 220

Noncondensable gas main pipe 221

Evacuation pipe 222

First noncondensable gas delivery line 223

Second non-condensable gas delivery line 224

Noncondensable gas draught fan 225

First shut-off valve 226

Second shutoff valve 227

Third flow regulating valve 228

First noncondensable gas flowmeter 229

Fourth flow control valve 230

Second noncondensable gas flowmeter 231

Natural gas pipeline 232

Third shut-off valve 233

Noncondensable gas analyzer 234

Non-condensable gas inlet pressure regulating valve 235

Non-condensable gas thermometer 236

Blower 237

First oxidant flow meter 238

Fifth flow control valve 239

Second oxidant flow meter 240

Sixth flow control valve 241

First flue gas thermometer 242

Second flue gas thermometer 243

Pyrolysis gas purification subsystem 3

Spray tower 301

Non-condensable gas outlet line 302

Second pyrolysis gas thermometer 303

Oil-water separation tank 304

Spray water cooling unit 305

Tar processing unit 306

Spray pump 307

Spraying water quantity regulating valve 308

Discharge subsystem 4

Atomized water pipeline 401

Closed slag tapping scraper 402

Product tank 403

Atomizing water jet 404

Coke discharge thermometer 405

Atomized water regulating valve 406

Fourth shutoff valve 407

Fifth shutoff valve 408

Pyrolysis residue processing unit 409

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions.

Example 1

As shown in fig. 1, the organic solid waste pyrolysis system of example 1 includes a feeding subsystem 1, a pyrolysis subsystem 2 and a pyrolysis gas purification subsystem 3 connected in sequence; the feed subsystem 1 includes a feed pipe 101; the pyrolysis subsystem 2 comprises a dividing wall rotary kiln 201, an in-kiln burner 203 and a non-condensable gas incinerator 204; the partition wall rotary kiln 201 comprises a feed inlet 202, a pyrolysis gas outlet 205, a jacket flue gas inlet 206 and a jacket flue gas outlet 207; the feeding pipe 101 is arranged through the feeding hole 202, and the outlet of the feeding pipe 101 is positioned inside the dividing wall rotary kiln 201; the in-kiln burner 203 is arranged on the kiln head 208 of the dividing wall rotary kiln 201; the pyrolysis gas outlet 205 is connected with the inlet of the pyrolysis gas purification subsystem 3 and is used for purifying the pyrolysis gas to obtain non-condensable gas; the pyrolysis gas purification subsystem 3 is connected with the in-kiln burner 203 through a first non-condensable gas conveying pipeline 223, and provides non-condensable gas for the combustion of the in-kiln burner 203; the pyrolysis gas purification subsystem 3 is connected with the inlet of the non-condensable gas incinerator 204 through a second non-condensable gas conveying pipeline 224 and is used for generating flue gas; the first outlet of the non-condensable gas incinerator 204 is connected with the jacket flue gas inlet 206; a jacket flue gas inlet 206 and a jacket flue gas outlet 207 are provided at both ends of the outer jacket of the dividing wall rotary kiln 201, respectively.

The in-kiln burner 203 burns the pyrolysis non-condensable gas in the partition wall rotary kiln 201, and the flame generated by the burning provides part of the heat required for the pyrolysis of the raw material in the form of radiant heat exchange. The first outlet of the non-condensable gas incinerator 204 is connected with the jacket flue gas inlet 206, and high-temperature flue gas obtained by incineration is used as the dividing wall rotary kiln 201 for heat exchange. Therefore, the heat exchange of the radiation in the kiln and the heat exchange of the dividing wall of the outer jacket meet the total heat required by the pyrolysis of the raw materials together.

The feed subsystem 1 also includes a feedstock storage tank and feedstock delivery equipment. The raw material storage tank is used for storing the dried raw materials. The raw material conveying apparatus includes a grab crane 103 and a silo 104. The grab crane 103 conveys the raw material in the raw material storage tank to the bin 104, and an outlet at the bottom of the bin 104 is connected with an inlet pipeline of the feeding pipe 101 to convey the raw material to the feeding pipe 101. The feed pipe 101 is also provided with a hydraulic plunger pump 105 and a piston push rod 102. A piston push rod 102 in a feeding pipe 101 is driven by a hydraulic plunger pump 105, raw materials are compressed in the feeding pipe 101 under the extrusion force, air in gaps of the raw materials is discharged, and the phenomenon that unmeasurable external air enters a downstream pyrolysis subsystem 2 along with the raw materials is reduced; meanwhile, the compressed raw material forms a material plug, and the high-temperature gas in the pyrolysis subsystem 2 operating at the micro-positive pressure is prevented from flowing backwards to the feeding pipe 101.

The two ends of the partition wall rotary kiln 201 are respectively a kiln head 208 and a kiln tail 209. One end of the dividing wall rotary kiln 201 close to the kiln head 208 is provided with a kiln head sealing cover 210, and the kiln head sealing cover 210 is rotationally connected with the dividing wall rotary kiln 201 to form dynamic and static sealing. The in-kiln burner 203 is fixed in the kiln head sealing cover 210. The feed tube 101 is fixed in the kiln head sealing cover 210.

As shown in fig. 2 and 3, the feeding pipe 101 is positioned above the in-kiln burner 203, the feeding pipe 101 is externally tangent to the in-kiln burner 203, and the feeding pipe 101 and the in-kiln burner 203 are internally tangent to the kiln head sealing cover 210 respectively; the center of the feeding pipe 101, the center of the in-kiln burner 203 and the center of the dividing wall rotary kiln 201 are on the same straight line. Therefore, the connecting line of the circle centers of the feeding pipe 101 and the in-kiln burner 203 is perpendicular to the material stacking surface (as shown in fig. 2, namely ═ a +. blit-b ═ 90 °), and the in-kiln burner 203 is positioned between the feeding pipe 101 and the material. According to the dynamic stacking angle of the materials in the kiln body, the angle between the feeding pipe 101 and the in-kiln burner 203 is determined, and the radiation heat exchange effect is optimized.

The kiln head 208 is of a necking structure to reduce the dynamic and static sealing area.

The kiln tail 209 of the dividing wall rotary kiln 201 is of a straight cylinder structure, and a kiln tail sealing cover of the dividing wall rotary kiln 201 is rotationally connected with the dividing wall rotary kiln 201 to form dynamic and static sealing.

The partition wall rotary kiln 201 also comprises a material outlet 211; the material outlet 211 is positioned below the kiln tail 209 of the dividing wall rotary kiln 201, and the material outlet 211 is used for recovering materials pyrolyzed by the dividing wall rotary kiln 201. The kiln tail sealing cover of the partition wall rotary kiln 201 is also provided with a first pyrolysis gas thermometer 212 and a pyrolysis gas pressure gauge 213.

The pyrolysis subsystem 2 further comprises a first flue gas branch 214, a second flue gas branch 215 and a flue gas main 216; the jacket flue gas outlet 207 is connected with the inlet of the first flue gas branch 214; the second outlet of the non-condensable gas incinerator 204 is connected with the inlet of the second flue gas branch 215, and the first flue gas branch 214 and the second flue gas branch 215 are converged into a flue gas main 216. The outlet of the flue gas main 216 is connected with a raw material drying unit 217 and a flue gas purifying unit 218 in sequence. The first flue gas branch 214 is provided with a first flow regulating valve 219, the second flue gas branch 215 is provided with a second flow regulating valve 220, and the first flow regulating valve 219 and the second flow regulating valve 220 are used for regulating the proportion of the flue gas flow distributed to the outer jacket of the dividing wall rotary kiln 201 and the flue gas flow of the second flue gas branch 215.

A first flue gas thermometer 242 is arranged in a pipeline connecting the first outlet of the non-condensable gas incinerator 204 with the jacket flue gas inlet 206, and a second flue gas thermometer 243 is also arranged on the first flue gas branch 214.

The pyrolysis subsystem 2 further comprises a noncondensable gas main pipeline 221, an emptying pipe 222 and a natural gas pipeline 232; an inlet of the noncondensable gas main pipeline 221 is connected with the pyrolysis gas purification subsystem 3, an outlet of the noncondensable gas main pipeline 221 is respectively connected with a first noncondensable gas conveying pipeline 223 and a second noncondensable gas conveying pipeline 224, and the noncondensable gas main pipeline 221 is provided with a noncondensable gas induced draft fan 225, a first shut-off valve 226, a drain port and a natural gas inlet; an inlet of the emptying pipe 222 is connected with an emptying port of the noncondensable gas main pipeline 221, and a second shut-off valve 227 is arranged on the emptying pipe 222; the outlet of the natural gas line 232 is connected to the natural gas inlet, and the natural gas inlet is located in the line downstream of the first shut-off valve 226. The first noncondensable gas feed pipe 223 is provided with a third flow rate adjustment valve 228 and a first noncondensable gas flow meter 229. A fourth flow rate regulating valve 230 and a second non-condensable gas flow meter 231 are arranged in the second non-condensable gas conveying pipeline 224. The natural gas pipeline 232 is provided with a third shut-off valve 233 for switching in or switching off natural gas. The outlet of the non-condensable gas induced draft fan 225 is also provided with a non-condensable gas analyzer 234. The noncondensable gas fuel gas analyzer 234 may detect information such as a calorific value, an oxygen content, and the like of the noncondensable gas.

The pyrolysis subsystem 2 further comprises a non-condensable gas inlet pressure regulating valve 235 and a non-condensable gas thermometer 236, wherein the non-condensable gas inlet pressure regulating valve 235 and the non-condensable gas thermometer 236 are arranged in a pipeline connected with the non-condensable gas induced draft fan 225 and the pyrolysis gas purification subsystem 3. The pressure of the pyrolysis gas pressure gauge 213 can be controlled by adjusting the non-condensable gas inlet pressure adjusting valve 235 through piezoresistive throttling, the micro-positive pressure operation of the partition wall rotary kiln 201 is maintained, and the non-condensable gas temperature reduction and tar removal conditions can be monitored by using the non-condensable gas thermometer 236.

The pyrolysis subsystem 2 further comprises a blower 237 for providing air and/or oxygen to the pyrolysis subsystem 2; a first outlet line of the blower 237 is connected to the in-kiln burner 203, and a second outlet line of the blower 237 is connected to an inlet of the noncondensable gas incinerator 204.

A first oxidant flow meter 238 and a fifth flow regulating valve 239 are arranged on a first outlet pipeline of the blower 237; a second oxidant flow meter 240 and a sixth flow control valve 241 are provided on a second outlet line of the blower 237. The fifth flow regulating valve 239 and the third flow regulating valve 228 can be controlled to enable the air coefficient in the partition wall rotary kiln 201 to be about 0.7, so that micro-anoxic combustion of the combustor 203 in the kiln is realized, and unreacted oxygen is prevented from being mixed into high-temperature pyrolysis gas; in addition, the sixth flow regulating valve 241 and the fourth flow regulating valve 230 can be controlled to ensure that the temperature of the flue gas at the outlet of the non-condensable gas incinerator 204 is about 650 ℃, so as to prevent the overtemperature of the pipeline and the barrel of the dividing wall rotary kiln 201.

The pyrolysis gas purification subsystem 3 comprises a spray tower 301, an inlet of the spray tower 301 is connected with a pyrolysis gas outlet 205, and a non-condensable gas outlet pipeline 302 of the spray tower 301 is connected with a non-condensable gas main pipeline 221 and then respectively connected with a first non-condensable gas conveying pipeline 223 and a second non-condensable gas conveying pipeline 224. A second pyrolysis gas thermometer 303 is arranged in a pipeline connecting the inlet of the spray tower 301 with the pyrolysis gas outlet 205. The liquid outlet of the spray tower 301 is connected to an oil-water separation tank 304, and the oil-water separation tank 304 is located below the spray tower 301 for oil-water separation. The water phase outlet of the oil-water separation tank 304 is connected with a spray water cooling unit 305; the oil phase outlet of the oil-water separation tank 304 is connected with a tar treatment unit 306. The spray water cooling unit 305 may employ closed air cooling. The water phase outlet of the oil-water separation tank 304 is connected to the spray water cooling unit 305 and the spray tower 301 in sequence, so that the spray water of the spray tower 301 can be recycled. The spray water cooling unit 305 is also connected to the spray water line 401 of the tapping subsystem 4. A spray pump 307 and a spray water quantity regulating valve 308 are also arranged in a pipeline connecting the spray water cooling unit 305 and the spray tower 301.

The organic solid waste pyrolysis system also comprises a discharging subsystem 4; the discharging subsystem 4 is connected with a material outlet 211 of the dividing wall rotary kiln 201. The discharge subsystem 4 comprises a closed tapping scraper 402 and a product storage tank 403 connected in series. The closed slag tapping scraper 402 is provided with a plurality of atomizing water nozzles 404 along the advancing direction of the pyrolysis carbon residue. A plurality of atomizing water nozzles 404 are arranged on the atomizing water pipeline 401; the outlet of the closed slag scraper 402 is provided with a coke discharging thermometer 405, and the atomized water pipeline 401 is provided with an atomized water regulating valve 406 to regulate the spraying amount, so that the temperature measured by the coke discharging thermometer 405 is maintained at 150-200 ℃, and semi-dry coke quenching of pyrolytic residual carbon is realized. The discharging subsystem 4 adopts a closed semi-dry coke quenching process, so that the air tightness of the system is increased, the reutilization of discharged slag is improved, and no wastewater is generated. A fourth shut-off valve 407 is arranged in the outlet pipeline of the closed slag scraper 402, and a fifth shut-off valve 408 is arranged in the outlet pipeline of the product storage tank 403.

The outlet of the product storage tank 403 is connected to the pyrolysis residue treatment unit 409, and the pyrolysis residue is sent to the pyrolysis residue treatment unit 409, and after the metal is separated and recovered, the harmless treatment is performed, such as sanitary landfill, direct incineration or gasification raw material.

The organic solid waste pyrolysis method of the organic solid waste pyrolysis system of example 1 includes the steps of:

organic solid waste is conveyed to a dividing wall rotary kiln 201 through a feeding pipe 101 and is combusted through an in-kiln combustor 203 to obtain pyrolysis gas; the pyrolysis gas is conveyed to a pyrolysis gas purification subsystem 3, and the pyrolysis gas is purified to obtain non-condensable gas; dividing the non-condensable gas into at least two parts, and conveying one part of the non-condensable gas to the in-kiln combustor 203 to provide the non-condensable gas for the combustion of the in-kiln combustor 203; part of the non-condensable gas is conveyed to a non-condensable gas incinerator 204, and flue gas is obtained through incineration; the flue gas is conveyed to the outer jacket of the dividing wall rotary kiln 201 to provide heat for the dividing wall rotary kiln 201.

As shown in fig. 4, the start-up of the organic solid waste pyrolysis system includes: a partition wall rotary kiln 201 starting step, a noncondensable gas incinerator 204 starting step, an oxygen replacement step in the partition wall rotary kiln 201, a load increasing and adjusting step, a step of replacing natural gas with noncondensable gas and a system dynamic balancing step;

the partition wall rotary kiln 201 starting step comprises:

s1.1, in a system cold state, the dividing wall rotary kiln 201 starts to rotate at a low speed (0.5r/min), positioning scales of a kiln head 208 and a kiln tail 209 of the dividing wall rotary kiln 201 are checked in the rotating process, and whether the radial runout of a kiln body of the dividing wall rotary kiln 201 is less than or equal to 1.5mm and the axial positioning meets the sealing requirements of a kiln head sealing cover 210 and a kiln tail sealing cover or not is determined;

s1.2, gradually increasing the rotating speed of the dividing wall rotary kiln 201 to a rated rotating speed (2r/min), and checking the condition that the rotation and the jumping of a kiln body of the dividing wall rotary kiln 201 are less than or equal to 1.5 mm;

the starting steps of the non-condensable gas incinerator 204 include:

s2.1, starting the spray tower 301, the spray water cooling unit 305 and the spray pump 307, and adjusting the spray water amount to be 30t/h and the water temperature to be below 35 ℃;

s2.2, opening a second shut-off valve 227, closing a first shut-off valve 226, starting a non-condensable gas induced draft fan 225, setting the frequency to be 20Hz, and adjusting the opening degree of a non-condensable gas inlet pressure adjusting valve 235 to be 30% so that the pyrolysis gas pressure gauge 213 displays micro negative pressure (-100Pa to-50 Pa);

s2.3, opening a third shut-off valve 233, opening a blower 237, setting the frequency to be 40Hz, and coordinately controlling the valve opening degrees of a third flow regulating valve 228, a fifth flow regulating valve 239, a fourth flow regulating valve 230 and a sixth flow regulating valve 241 to enable the in-kiln burner 203 to burn in a slight oxygen deficiency mode (the natural gas flow is 7 Nm)³H, excess air ratio of 0.7), and normal combustion of the noncondensable gas incinerator 204 (natural gas flow rate of 10Nm³H, the excess air coefficient is 1.1; preheating the kiln body of the dividing wall rotary kiln 201 through the non-condensable gas incinerator 204 and the in-kiln burner 203, and replacing air in the dividing wall rotary kiln 201 with flue gas;

s2.4, adjusting the opening of the non-condensable gas inlet pressure adjusting valve 235 to 80%, and keeping the pyrolysis gas pressure gauge 213 to display micro negative pressure so as to keep the micro negative pressure (-100Pa to-50 Pa) in the kiln body of the partition wall rotary kiln 201 stable;

the oxygen replacement step in partition wall rotary kiln 201 includes:

s3.1, adjusting the opening of a non-condensable gas inlet pressure adjusting valve 235 to 70%, and keeping a pyrolysis gas pressure gauge 213 to display micro positive pressure (+50Pa to +100 Pa);

s3.2, keeping the in-kiln combustor 203 in a micro-anoxic combustion state, and observing that the oxygen concentration measured by the non-condensable gas analyzer 234 is gradually reduced to a safety range (reduced to 0.03% Vol.) from 21% (namely the oxygen concentration in the air); until the oxygen replacement in the dividing wall rotary kiln 201 and the pyrolysis gas pipeline thereof is complete;

the load increasing and adjusting step comprises the following steps:

s4.1, taking a second pyrolysis gas thermometer 303 (reaching 200 ℃) as a preheating degree judgment index of a pyrolysis gas pipeline, and preventing the pyrolysis gas from being condensed and blocked in the pipeline due to low temperature;

s4.2, starting the hydraulic plunger pump 105, starting feeding with a small load (40%), and observing the pressure change condition of an oil hydraulic cylinder of the hydraulic plunger pump 105 (reflecting the extrusion condition of the material in the feeding pipe 101 and the formed material plug shape) in the feeding process; simultaneously adjusting the air volume of a non-condensable gas induced draft fan 225 to 30Hz and the opening degree of a non-condensable gas inlet pressure regulating valve 235 to 75%, and keeping a pyrolysis gas pressure gauge 213 to display micro positive pressure (+50Pa to +100 Pa);

s4.3, gradually increasing the load until the load reaches 100%;

s5.1, observing the form of pyrolysis residues discharged by the discharging subsystem 4, and judging whether the materials are pyrolyzed sufficiently or not; the heat value (about 4.5 MJ/Nm) measured by the noncondensable gas fuel gas analyzer 234³) Judging whether the quality of the non-condensable gas reaches the standard (namely judging whether the stable combustion requirement is met);

s5.2, opening the first shut-off valve 226, and closing the second shut-off valve 227 to convey the non-condensable gas into the non-condensable gas main pipeline 221; gradually reducing the opening degree of the third shut-off valve 233 until the third shut-off valve 233 is completely closed, so that the natural gas is completely cut off; simultaneously, the air quantity of the blower 237 and the opening degrees of the fifth flow regulating valve 239 and the sixth flow regulating valve 241 are regulated, and the micro-anoxic combustion of the in-kiln combustor 203 and the normal combustion of the non-condensable gas incinerator 204 are kept;

the dynamic balancing step of the system comprises the following steps:

s6.2, observing a first pyrolysis gas thermometer 212 (whether the temperature of the pyrolysis gas reaches 450 ℃), a pyrolysis gas pressure gauge 213 (whether the dividing wall rotary kiln 201 is stable in operation at about +80 Pa), a non-condensable gas thermometer 236 (whether the spray tower 301 works normally at 40 ℃), and a non-condensable gas analyzer 234 (whether the heat value and the oxygen concentration level of the non-condensable gas reach the standard, and whether the heat value reaches 4.5MJ/Nm³And the oxygen concentration is 0.08% Vol.), and the measurement results of the first flue gas thermometer 242 and the second flue gas thermometer 243 (whether the heat provided by the flue gas in the outer jacket of the partition wall rotary kiln 201 is sufficient, and the temperature of the first flue gas thermometer 242 and the temperature of the second flue gas thermometer 243 are respectively about 650 ℃ and 160 ℃) indicate that the system has achieved stable operation when the set target is reached.

As shown in fig. 5, the processing steps of the organic solid waste pyrolysis system for non-condensable gas with low heat value or excessive oxygen content include: a step of replacing non-condensable gas with natural gas, a step of load reduction and adjustment, a step of replacing oxygen in the dividing wall rotary kiln 201, a step of load increase and adjustment, a step of replacing natural gas with non-condensable gas and a step of dynamic balance of a system;

s1.1, slowly opening the opening degree of a third shut-off valve 233, conveying a small amount of natural gas to a noncondensable gas main pipeline 221, and improving the heat value of the noncondensable gas so as to keep the combustion stability of the in-kiln combustor 203 and the noncondensable gas incinerator 204;

s1.2, in the process of opening the opening degree of the third shut-off valve 233, slowly increasing the opening degree of the second shut-off valve 227 and reducing the opening degree of the first shut-off valve 226 until the third shut-off valve 233 and the second shut-off valve 227 are completely opened and the first shut-off valve 226 is closed; in the process, the in-kiln combustor 203 is maintained to burn under the condition of micro-anoxic condition, the non-condensable gas incinerator 204 burns normally, and the pyrolysis gas pressure gauge 213 displays micro-positive pressure (+50Pa to +100 Pa);

the load reducing and adjusting step comprises the following steps:

s2.1, reducing the material pushing frequency of the hydraulic plunger pump 105, reducing the material feeding amount to a small load (30%), observing the pressure change conditions of an oil hydraulic cylinder of the hydraulic plunger pump 105 and a pyrolysis gas pressure gauge 213 in the process, and maintaining the material plug sealing of the feeding pipe 101 and the partition wall rotary kiln 201 to operate under the micro-positive pressure condition;

s2.2, reducing the air volume of the air blower 237, reducing the opening degree of the third shut-off valve 233 and reducing the natural gas flow; so as to reduce the thermal power of the in-kiln burner 203 and the non-condensable gas incinerator 204;

the oxygen replacement step in the partition wall rotary kiln 201 includes (may be the same as the oxygen replacement step in the partition wall rotary kiln 201 in the start-up of the organic solid waste pyrolysis system):

s3.1, adjusting the opening of a non-condensable gas inlet pressure adjusting valve 235, and keeping a pyrolysis gas pressure gauge 213 to display micro-positive pressure;

s3.2, keeping the in-kiln burner 203 in a micro-anoxic combustion state, and observing that the oxygen concentration measured by the non-condensable gas analyzer 234 is gradually reduced to a safety range (less than or equal to 0.5% Vol); until the oxygen replacement in the dividing wall rotary kiln 201 and the pyrolysis gas pipeline thereof is complete;

the load increasing and adjusting step comprises (can be the same as the load increasing and adjusting step in the starting of the organic solid waste pyrolysis system):

s4.1, taking a second pyrolysis gas thermometer 303 as a preheating degree judgment index of a pyrolysis gas pipeline to prevent the pyrolysis gas from being condensed and blocked in the pipeline due to low temperature;

s4.2, starting the hydraulic plunger pump 105, starting feeding with a small load (30% -50%), and observing the pressure change condition of an oil hydraulic cylinder of the hydraulic plunger pump 105 (reflecting the extrusion condition of the material in the feeding pipe 101 and the formed material plug shape) in the feeding process; simultaneously adjusting the air quantity of a non-condensable gas induced draft fan 225 and the opening degree of a non-condensable gas inlet pressure regulating valve 235, and keeping a pyrolysis gas pressure gauge 213 to display micro-positive pressure;

s4.3, gradually increasing the load until the load reaches 100%;

the step of replacing the natural gas with the non-condensable gas comprises (can be the same as the step of replacing the natural gas with the non-condensable gas in the starting of the organic solid waste pyrolysis system):

s5.1, observing the form of pyrolysis residues discharged by the discharging subsystem 4, and judging whether the materials are pyrolyzed sufficiently or not; judging whether the quality of the non-condensable gas reaches the standard (namely judging whether the stable combustion requirement is met) according to the heat value measured by the non-condensable gas fuel gas analyzer 234;

the system dynamic balancing step comprises (may be the same as the system dynamic balancing step in the start-up of the organic solid waste pyrolysis system):

s6.2, observing measurement results of a first pyrolysis gas thermometer 212 (whether the pyrolysis gas temperature reaches the standard), a pyrolysis gas pressure gauge 213 (whether the dividing wall rotary kiln 201 runs at a stable micro-positive pressure), a non-condensable gas thermometer 236 (whether the spray tower 301 works normally), a non-condensable gas analyzer 234 (whether the non-condensable gas heat value and the oxygen concentration level reach the standard), a first flue gas thermometer 242 and a second flue gas thermometer 243 (whether the flue gas in an outer jacket of the dividing wall rotary kiln 201 provides sufficient heat), and indicating that the system runs stably if a set target is reached.

As shown in fig. 6, the blowing out of the organic solid waste pyrolysis system includes: a step of replacing non-condensable gas with natural gas, a step of load reduction and adjustment, a step of cutting off natural gas and a step of shutting down the dividing wall rotary kiln 201;

the step of replacing non-condensable gas with natural gas comprises the following steps:

s1.2, in the process of opening the opening degree of the third shut-off valve 233, slowly increasing the opening degree of the second shut-off valve 227 and reducing the opening degree of the first shut-off valve 226 until the third shut-off valve 233 and the second shut-off valve 227 are completely opened and the first shut-off valve 226 is closed; in the process, the in-kiln burner 203 is maintained to burn under the condition of micro-anoxic condition, the non-condensable gas incinerator 204 burns normally, and the pyrolysis gas pressure gauge 213 displays micro-positive pressure;

the load reducing and adjusting step comprises the following steps:

s2.1, stopping the pushing and feeding action of the hydraulic plunger pump 105;

s2.2, continuously running the dividing wall rotary kiln 201 at a rated rotating speed until all materials in the dividing wall rotary kiln 201 are discharged;

the natural gas cutting step comprises the following steps:

s3, closing the third flow regulating valve 228 and the third closing valve 233, closing the blower 237, and closing the in-kiln burner 203;

the shutdown steps of the dividing wall rotary kiln 201 comprise:

s4.1, observing that the gas heat value detected by the non-condensable gas analyzer 234 is reduced to 0, namely after all combustible gas components in the dividing wall rotary kiln 201 and pipelines thereof are completely replaced, starting a blower 237, starting a fifth flow regulating valve 239, so that external cold air is conveyed into the dividing wall rotary kiln 201 from the in-kiln burner 203, observing that the oxygen concentration detected by the non-condensable gas analyzer 234 is recovered to 21%, indicating that the smoke in the kiln body is completely replaced, and then closing the blower 237;

s4.2, reducing the rotating speed of the dividing wall rotary kiln 201 until the dividing wall rotary kiln 201 is reduced to the safe shutdown temperature, and then closing the dividing wall rotary kiln 201.

Claims

1. An organic solid waste pyrolysis system is characterized by comprising a feeding subsystem, a pyrolysis subsystem and a pyrolysis gas purification subsystem which are sequentially connected;

the feed subsystem comprises a feed pipe;

the kiln inner burner is arranged on the kiln head of the dividing wall rotary kiln;

2. The organic solid waste pyrolysis system of claim 1 wherein the feed subsystem further comprises a feedstock storage tank and feedstock delivery equipment; preferably, the raw material conveying equipment comprises a grab crane and a storage bin;

and/or a hydraulic plunger pump and a piston push rod are also arranged in the pipeline of the feed pipe;

and/or a kiln head sealing cover is arranged at one end of the dividing wall rotary kiln close to the kiln head, and the kiln head sealing cover is rotationally connected with the dividing wall rotary kiln; preferably, the in-kiln burner is fixed in the kiln head sealing cover, and the feeding pipe is fixed in the kiln head sealing cover; preferably, the feeding pipe is positioned above the in-kiln burner, the feeding pipe is externally tangent to the in-kiln burner, the feeding pipe and the in-kiln burner are internally tangent to the kiln head sealing cover respectively, and the circle center of the feeding pipe, the circle center of the in-kiln burner and the circle center of the dividing wall rotary kiln are positioned on the same straight line;

and/or the kiln head of the in-kiln burner is of a necking structure;

and/or the kiln tail of the dividing wall rotary kiln is of a straight cylinder structure, and a kiln tail sealing cover of the dividing wall rotary kiln is rotationally connected with the dividing wall rotary kiln;

and/or the dividing wall rotary kiln also comprises a material outlet; the material outlet is positioned below the kiln tail of the dividing wall rotary kiln;

and/or the kiln tail sealing cover of the partition wall rotary kiln is also provided with a first pyrolysis gas thermometer and a pyrolysis gas pressure gauge.

3. The organic solid waste pyrolysis system of claim 1, wherein the pyrolysis subsystem further comprises a first flue gas branch, a second flue gas branch, and a flue gas manifold;

the jacket flue gas outlet is connected with the inlet of the first flue gas branch; a second outlet of the non-condensable gas incinerator is connected with an inlet of the second flue gas branch, and the first flue gas branch and the second flue gas branch are converged into the flue gas main path;

preferably, the outlet of the flue gas main path is sequentially connected with the raw material drying unit and the flue gas purification unit;

preferably, a first flow regulating valve is arranged on the first flue gas branch, and a second flow regulating valve is arranged on the second flue gas branch;

4. The organic solid waste pyrolysis system of claim 1, wherein the pyrolysis subsystem further comprises a non-condensable gas main, an evacuation pipe, and a natural gas line; an inlet of the non-condensable gas main pipeline is connected with the pyrolysis gas purification subsystem, an outlet of the non-condensable gas main pipeline is respectively connected with the first non-condensable gas conveying pipeline and the second non-condensable gas conveying pipeline, and a non-condensable gas induced draft fan, a first shut-off valve, an evacuation port and a natural gas inlet are arranged on the non-condensable gas main pipeline; an inlet of the emptying pipe is connected with an emptying port of the non-condensable gas main pipeline, and a second shut-off valve is arranged on the emptying pipe; the outlet of the natural gas pipeline is connected with the natural gas inlet, and the natural gas inlet is positioned in the pipeline downstream of the first shutoff valve;

preferably, a third flow regulating valve and a first non-condensable gas flow meter are arranged in the first non-condensable gas conveying pipeline;

preferably, a fourth flow regulating valve and a second non-condensable gas flowmeter are arranged in the second non-condensable gas conveying pipeline;

preferably, a third shut-off valve is arranged on the natural gas pipeline;

preferably, the outlet of the non-condensable gas induced draft fan is also provided with a non-condensable gas analyzer;

preferably, the pyrolysis subsystem further comprises a non-condensable gas inlet pressure regulating valve and a non-condensable gas thermometer, and the non-condensable gas inlet pressure regulating valve and the non-condensable gas thermometer are arranged in a pipeline connected with the non-condensable gas induced draft fan and the pyrolysis gas purification subsystem.

5. The organic solid waste pyrolysis system of claim 1 wherein the pyrolysis subsystem further comprises a blower for providing air and/or oxygen to the pyrolysis subsystem; a first outlet pipeline of the air feeder is connected with the in-kiln burner, and a second outlet pipeline of the air feeder is connected with an inlet of the non-condensable gas incinerator;

preferably, a first oxidant flow meter and a fifth flow regulating valve are arranged on a first outlet pipeline of the blower; and a second oxidant flow meter and a sixth flow regulating valve are arranged on a second outlet pipeline of the blower.

6. The organic solid waste pyrolysis system of claim 1, wherein the pyrolysis gas purification subsystem comprises a spray tower, an inlet of the spray tower is connected with the pyrolysis gas outlet, and a non-condensable gas outlet pipeline of the spray tower is respectively connected with the first non-condensable gas conveying pipeline and the second non-condensable gas conveying pipeline;

preferably, after being connected with a main noncondensable gas pipeline, a noncondensable gas outlet pipeline of the spray tower is respectively connected with the first noncondensable gas conveying pipeline and the second noncondensable gas conveying pipeline;

preferably, a second pyrolysis gas thermometer is arranged in a pipeline connecting the inlet of the spray tower and the pyrolysis gas outlet;

preferably, a liquid outlet of the spray tower is connected with an oil-water separation tank, and the oil-water separation tank is positioned below the spray tower;

preferably, a water phase outlet of the oil-water separation tank is connected with a spray water cooling unit; an oil phase outlet of the oil-water separation tank is connected with the tar treatment unit, or the oil phase outlet of the oil-water separation tank is connected with an inlet of the non-condensable gas incinerator;

preferably, a water phase outlet of the oil-water separation tank is sequentially connected with the spray water cooling unit and the spray tower;

further preferably, a spray pump and a spray water quantity regulating valve are further arranged in a pipeline connecting the spray water cooling unit and the spray tower.

7. The organic solid waste pyrolysis system of claim 6 further comprising a discharge subsystem; the discharging subsystem is connected with a material outlet of the dividing wall rotary kiln;

preferably, the discharge subsystem comprises a closed slag scraper and a product storage tank which are connected in sequence.

8. The organic solid waste pyrolysis system of claim 7, wherein the closed slag scraper is provided with a plurality of atomizing water nozzles along the proceeding direction of pyrolysis carbon residue;

and/or the discharging subsystem further comprises an atomized water pipeline, the spray water cooling unit is further connected with the atomized water pipeline of the discharging subsystem, and a plurality of atomized water nozzles are arranged on the atomized water pipeline;

preferably, a coke discharging thermometer is arranged at the outlet of the closed slag discharging scraper conveyor,

preferably, the atomized water pipeline is provided with an atomized water regulating valve;

preferably, a fourth shutoff valve is arranged in an outlet pipeline of the closed slag tapping scraper conveyor, and a fifth shutoff valve is arranged in an outlet pipeline of the product storage tank;

preferably, the outlet of the product storage tank is connected with a pyrolysis residue treatment unit.

9. An organic solid waste pyrolysis method, which is carried out by using the organic solid waste pyrolysis system as claimed in any one of claims 1 to 8, and comprises the following steps:

10. The organic solid waste pyrolysis method of claim 9, wherein the starting up of the organic solid waste pyrolysis system comprises: a dividing wall rotary kiln starting step, a noncondensable gas incinerator starting step, an oxygen replacement step in the dividing wall rotary kiln, a load increasing and adjusting step, a step of replacing natural gas with noncondensable gas and a system dynamic balancing step;

the partition wall rotary kiln starting step comprises the following steps:

s2.1, starting a spray tower, a spray water cooling unit and a spray pump;

s2.2, opening a second shutoff valve, closing the first shutoff valve, starting a non-condensable gas induced draft fan, and adjusting the opening degree of a non-condensable gas inlet pressure adjusting valve to enable a thermal gas pressure gauge to display micro negative pressure;

s2.3, opening a third shut-off valve, opening a blower, and coordinately controlling the valve opening degrees of a third flow regulating valve, a fifth flow regulating valve, a fourth flow regulating valve and a sixth flow regulating valve to ensure that the in-kiln combustor burns in a micro-anoxic mode and the noncondensable gas incinerator burns normally;

s2.4, adjusting the opening of a non-condensable gas inlet pressure adjusting valve, and keeping a pyrolysis gas pressure gauge to display micro-negative pressure;

s3.2, keeping the combustor in the kiln to be stable in a micro-anoxic combustion state, and observing that the oxygen concentration measured by the non-condensable gas analyzer is gradually reduced from 21% to a safety range; until the oxygen replacement in the dividing wall rotary kiln and a pyrolysis gas pipeline thereof is complete;

the load increasing and adjusting step comprises the following steps:

s4.2, starting the hydraulic plunger pump, starting feeding with a small load, and observing the pressure change condition of an oil hydraulic cylinder of the hydraulic plunger pump in the feeding process; simultaneously adjusting the air quantity of a non-condensable gas induced draft fan and the opening of a non-condensable gas inlet pressure adjusting valve, and keeping a pyrolysis gas pressure gauge to display micro-positive pressure;

s4.3, gradually increasing the load until the load reaches 100%;

s5.1, observing the form of pyrolysis residues discharged by the discharging subsystem, and judging whether the materials are pyrolyzed sufficiently or not; judging whether the quality of the non-condensable gas reaches the standard according to the heat value measured by a non-condensable gas analyzer;

s5.2, opening the first shutoff valve, and closing the second shutoff valve to convey the non-condensable gas into a non-condensable gas main pipeline; gradually reducing the opening degree of the third shut-off valve until the third shut-off valve is completely closed, so that the natural gas is completely cut off; simultaneously adjusting the air volume of the air feeder and the opening degrees of a fifth flow regulating valve and a sixth flow regulating valve, and keeping the micro-anoxic combustion of the in-kiln combustor and the normal combustion of the non-condensable gas incinerator;

the system dynamic balancing step comprises:

s6.2, observing measurement results of the first pyrolysis gas thermometer, the pyrolysis gas pressure gauge, the non-condensable gas thermometer, the non-condensable gas fuel gas analyzer, the first flue gas thermometer and the second flue gas thermometer, and indicating that the system achieves stable operation when a set target is reached;

or the treatment steps of low calorific value or excessive oxygen content of the non-condensable gas of the organic solid waste pyrolysis system comprise: the method comprises the steps of natural gas replacing noncondensable gas, load reduction and adjustment, oxygen replacement in a dividing wall rotary kiln, load increase and adjustment, natural gas replacing by noncondensable gas and system dynamic balance;

the load reduction step comprises:

s2.1, reducing the material pushing frequency of a hydraulic plunger pump, reducing the feeding amount to a small load, observing the pressure of an oil hydraulic cylinder of the hydraulic plunger pump and the pressure change condition of a pyrolysis gas pressure gauge in the process, and maintaining the material plug sealing of a feeding pipe and the partition wall rotary kiln to operate under a micro-positive pressure condition;

s3.2, keeping the combustor in the kiln in a micro-anoxic combustion state, and observing that the oxygen concentration measured by the non-condensable gas analyzer is gradually reduced to a safety range; until the oxygen replacement in the dividing wall rotary kiln and a pyrolysis gas pipeline thereof is complete;

the load increasing and adjusting step comprises the following steps:

s4.3, gradually increasing the load until the load reaches 100%;

s5.2, opening the first shut-off valve, closing the second shut-off valve, and conveying the non-condensable gas into a non-condensable gas main pipeline; gradually reducing the opening degree of the third shut-off valve until the third shut-off valve is completely closed, so that the natural gas is completely cut off; simultaneously adjusting the air volume of the blower and the opening degree of a fifth flow regulating valve and a sixth flow regulating valve, and keeping the micro-anoxic combustion of the in-kiln combustor and the normal combustion of the non-condensable gas incinerator;

the system dynamic balancing step comprises:

or, the blowing out of the organic solid waste pyrolysis system comprises: a step of replacing non-condensable gas with natural gas, a step of load reduction and adjustment, a step of cutting off the natural gas and a step of shutting down a dividing wall rotary kiln;

the load reduction step comprises:

s2.1, stopping the pushing and feeding action of the hydraulic plunger pump;

the natural gas cutting step comprises:

s3, closing the third flow regulating valve and the third shutoff valve, closing the air feeder, and closing the in-kiln combustor;

s4.1, observing that the gas calorific value detected by the noncondensable gas analyzer is reduced to 0, starting a blower, starting a fifth flow regulating valve to convey external cold air from the in-kiln combustor to the dividing wall rotary kiln, and observing that the oxygen concentration detected by the noncondensable gas analyzer is recovered to 21%, namely, closing the blower;