KR101262097B1 - Continuous low-temperature pyrolysis system with preventing explosion - Google Patents

Abstract

PURPOSE: A continuous low-temperature pyrolysis device with a function for preventing explosion is provided to perform a low-temperature pyrolysis process by preventing scales from generating and by preventing circulating gas from being changed to oil at an inappropriate position by the temperature degradation of a pipe. CONSTITUTION: A continuous low-temperature pyrolysis device(1) with a function for preventing explosion comprises an injection hopper(10), a transfer and compression screw conveyor(20), a pyrolysis main body(30), a cyclone(40), a heat exchanger(50), a gas condenser(60), a recycle gas tank(70), a gas circulation device(80), an oil tank(90), and an LPG supply tank(100). A first transfer and compression screw conveyor(201) and a second transfer and compression screw conveyor(202) are subsequently installed while being connected to the injection hopper and are connected to the pyrolysis main body.

Description

Continuous low temperature pyrolysis unit with explosion protection {CONTINUOUS LOW-TEMPERATURE PYROLYSIS SYSTEM WITH PREVENTING EXPLOSION}

The present invention is due to the problem that the oil is generated in an inappropriate position due to the temperature drop of the pipe during the movement of the non-condensable gas generated in the main body of the pyrolysis device, due to the formation of scale due to the mixing of tar and dust Continuous low-temperature pyrolysis device that solves the problem of the prior art that the explosion caused by gas circulation failure due to blockage of the pipes, so that waste polymer compounds can be pyrolyzed at low temperature and regenerated into oil and gas in a safe state where explosions are prevented. It is about.

Pyrolysis is a system that heats waste to low temperature (300 ~ 600 ℃) under an oxygen-free or low oxygen atmosphere. Combustion is by exothermic reaction, but pyrolysis is by endothermic reaction. The reaction at 300-600 ° C., where the carbon chain is cut long to produce liquid oil, is called a liquefaction process. The reaction in which gas is cut short after 750 ° C. is called a gasification process.

Pyrolysis products vary depending on the size of the carbon chain and the type of waste used for pyrolysis. For example, pyrolysis of polystyrene increases the content of styrene as a monomer. Also, what remains in the furnace by the above pyrolysis is carbide, which is also called Char in other words, and includes pure carbon and metal soil.

Regarding the pyrolysis technology, Republic of Korea Patent Registration 10-0319350 (Registration Date December 18, 2001) 'Low Temperature Pyrolysis Method of Waste Tire Using Supercritical Fluid', Republic of Korea Patent Registration 10-0777616 (Registration Date November 2007 13 1) 'Low temperature pyrolysis device of high carbonaceous industrial waste', Republic of Korea Patent Registration 10-0945529 (Registration date February 25, 2010) has been disclosed a technology for 'low temperature pyrolysis emulsification system of waste plastic'.

However, the existing pyrolysis technology was difficult to control due to the complicated process due to the overlapping process. Especially, clogging occurred due to the scale of pipes caused by fly ash generated from the pyrolyzer body. This acted as an insecure factor. The precedent of industrial accidents caused by the explosion caused by driving in the state in which these unsafe elements are inherent was found in the media and newspaper reports.

The gas generated by the pyrolysis process is recovered to oil through the condensation and purification process, at which time non-condensable gas that is not recovered to oil is generated. Others were limited to incineration of non-condensable gases with RTO, or combustion to produce steam.

Pyrolysis uses burners to maintain the temperature of 500 ℃, but LPG and LNG are not economical in case of gas supplied to the heat source, and excessive bleeding occurs due to the cost of auxiliary fuel.

Republic of Korea Patent Registration 10-0319350 (Registration date December 18, 2001) Republic of Korea Patent Registration 10-0777616 (Registration date November 13, 2007) Republic of Korea Patent Registration 10-0945529 (Registration date February 25, 2010)

In order to solve the above problems, the present invention is a low-temperature pyrolysis of the waste polymer compound to be regenerated into oil and gas, the problem that the gas circulated through the pipe is changed to the oil at an inappropriate position according to the temperature drop of the pipe and tar (Tar) By solving the problem that scale occurs due to the mixing of dust and dust, continuous low-temperature pyrolysis to safely prevent low-temperature pyrolysis process by preventing explosion accident due to gas circulation disturbance caused by blockage of the pipe. It is an object of the invention to provide a device.

To achieve the above object,

The present invention is an injection hopper for injecting waste polymer compound,

In order to smoothly transfer the waste polymer compound introduced through the input hopper and minimize the mixing with the external oxygen, a two-stage transfer and compression screw conveyor that operates only by the transfer and compression of the screw,

Pyrolysis body for the low-temperature pyrolysis of the waste polymer compound supplied through the conveying, compression screw conveyor by indirect heating while the screw rotates,

Cyclone to remove the tar and dust contained in the non-condensing gas generated from the pyrolysis body,

A heat exchanger for condensing the non-condensable gas from which tar and dust are removed through the cyclone into oil, and transferring the non-condensed gas to an oil tank installed outside;

A gas condenser for cooling and condensing the non-condensable gas that has passed through the heat exchanger and transferring it to an oil tank installed outside;

A recycle gas tank for storing the non-condensable gas that has passed through the gas condenser and reusing it as a heat source of the pyrolysis body;

A gas circulation device for circulating the gas stored in the recycle gas tank to a burner installed at a lower end of the pyrolysis body,

An oil tank storing oil generated in the heat exchanger and a gas condenser;

LPG supply tank for supplying the initial ignition heat source of the burner installed at the bottom of the pyrolysis body to supply LPG gas to the point of generation of decomposition gas,

Install the screw inside the pipe connected from the pyrolysis body to the heat exchanger to rotate, the low temperature pyrolysis device having an explosion-proof function to maintain the temperature of the pipe at 220 ~ 400 ℃ as the main technical configuration.

The continuous low temperature pyrolysis apparatus according to the present invention prevents the mixing of external oxygen by allowing the two-stage primary and secondary conveying and compression screw conveyors for inputting waste polymer compounds to operate only by conveying and compressing the screws. Eliminate the risk of explosion by preventing the leakage of gas inside.

And, by installing a screw inside the pipe connected from the pyrolysis body to the heat exchanger to operate, and also maintain the temperature of the pipe at 220 ~ 400 ℃ to prevent the condensation of non-condensable gas to generate oil, scale of the pipe Minimizing the occurrence can eliminate the risk of explosion.

In addition, as an external heat source for indirect heating of the pyrolysis body, LPG is initially used to increase the temperature at an appropriate temperature, but after decomposition gas is generated, pyrolysis is performed using the regeneration gas collected in the gas tank. Heating the body has the advantage that no extra fuel cost is required.

1 is a schematic view showing the overall configuration of a continuous low temperature pyrolysis apparatus according to the present invention.
Figure 2 is a front view showing a conveying, compression screw conveyor according to the present invention.
Figure 3 is an actual picture of the conveying, compression screw conveyor in accordance with the present invention.
Figure 4 is a front view showing a pyrolysis body according to the present invention.
Figure 5 is a side view showing a pyrolysis body according to the present invention.
6 is a view showing a pipe configuration for explosion protection of the continuous low temperature pyrolysis apparatus according to the present invention.
7 is a schematic view showing a gas circulation device according to the present invention.

Hereinafter, the technical contents of the above description will be described with reference to the drawings.

Continuous low temperature pyrolysis apparatus 1 according to the present invention, as shown in Figure 1,

An input hopper 10 for introducing waste polymer compounds,

In order to smoothly transport the waste polymer compound introduced through the input hopper 10 and to minimize the mixing with external oxygen, the feed and compression screw conveyor 20 of the two-stage structure is operated only by the conveyance and compression of the screw,

Pyrolysis body 30 for the low-temperature pyrolysis of the waste polymer compound supplied through the transfer and compression screw conveyor 20 by indirect heating while the screw rotates,

Cyclone 40 to remove tar and dust contained in the non-condensing gas generated from the pyrolysis body 30,

A heat exchanger 50 for condensing the non-condensable gas from which tar and dust are removed through the cyclone 40 to an oil, and transferring the non-condensable gas to an oil tank installed outside;

A gas condenser 60 for cooling and condensing the non-condensable gas that has passed through the heat exchanger 50 to an oil tank installed at the outside;

A recycle gas tank 70 for storing the non-condensable gas that has passed through the gas condenser 60 and reusing it as a heat source of the pyrolysis body 30;

A gas circulation device (80) for circulating the gas stored in the recycle gas tank (70) to a burner installed at a lower end of the pyrolysis body (30);

An oil tank 90 storing oil generated by the heat exchanger and the gas condenser 50 and 60;

LPG supply tank 100 for supplying the initial ignition heat source of the burner installed at the lower end of the pyrolysis body 30 to supply the LPG gas to the point of generation of the decomposition gas.

In particular, the present invention, in order to prevent the explosion accident that may occur due to blockage of the pipe, the technical configuration of the slope and the compression zone in the conveying and compression screw conveyor 20, and from the pyrolysis body 30 to the heat exchanger (50) The technical features of the technical configuration to form a screw in the interior of the pipe to be connected to, to maintain a constant temperature inside the pipe.

The conveying and compressing screw conveyor 20 is a primary conveying and compressing screw conveyor 201 and a secondary conveying and compressing screw conveyor so as to have an inclination of 30 to 40 degrees upward from the ground in a state connected to the feed hopper 10. Reference numeral 202 is formed to be connected to the thermal decomposition body 30 of the rear stage (FIGS. 2 and 3).

Then, from the point connected with the pyrolysis body 30 to the 2/10 to 3/10 point of the total length of the secondary conveying and compression screw conveyor 202, a space in which no screw is formed is formed, and the space is compressed John's.

The inclination acts as an important element in configuring the conveyance and compression screw conveyor 20, and it is determined whether the gas generated in the pyrolysis body 30 can be prevented from being discharged to the outside according to the inclination.

In the low temperature pyrolysis process according to the present invention, first, the waste polymer compound introduced through the input hopper 10 is transferred along the primary conveying / compressing screw conveyor 201 and the secondary conveying / compressing screw conveyor 202 to the 2 The compression zone formed at the rear end of the vehicle feed / compression screw conveyor 202 is completely filled.

When the low temperature pyrolysis process starts, the waste polymer compound filled in the compression zone is pressurized by the waste polymer compound which is continuously supplied through the primary feed / compression screw conveyor 201 and the secondary transfer / compression screw conveyor 202. This occurs and is compressed and supplied to the pyrolysis body 30. At this time, when the slope is less than 30 °, some spaces in the compression zone remain unfilled by the waste polymer compound, and thus compression is not performed properly, and the gas generated in the pyrolysis body 30 may be discharged to the outside. In case of exceeding 40 °, a problem of cost increase occurs due to power consumption. Therefore, the inclination of the feed / compression screw conveyor 20 is preferably maintained at 30 to 40 °.

In other words, by the technical configuration of the transfer and compression screw conveyor 20, the waste polymer compound, which is a low-temperature pyrolysis raw material, is continuously introduced to block the inflow of oxygen from the outside, and to prevent the gas generated from the inside from leaking to the outside. Can give

And by installing a screw in the interior of the pipe connected from the pyrolysis body 30 to the heat exchanger 50, by maintaining the internal temperature of the pipe at 220 ~ 400 ℃, non-condensation discharged from the pyrolysis body 30 It can prevent condensation gas condensation and prevent oil formation at the unsuitable point, and also minimize the generation of scale inside the pipe, thereby preventing the blockage of the pipe and prevent explosion during low temperature pyrolysis process.

In addition, it is included in the technical configuration for the removal of tar (tar) and dust and the like to achieve the effect of the explosion protection required in the present invention, the technical configuration for this to be described later in sequence with each technical configuration do.

The inlet hopper 10 is a place for injecting the waste polymer compound, the waste polymer compound introduced through the inlet hopper 10 is the rear end pyrolysis body 30 through the conveying and compression screw conveyor 20 of the rear end Is transferred to.

The conveying and compression screw conveyor 20 has a two-stage structure including a primary conveying and compression screw conveyor 201 and a secondary conveying and compression screw conveyor 202, as shown in Figs. .

The conveying and compression screw conveyor 20 uses a compression screw conveyor for blocking the inflow of oxygen and preventing the leakage of internal gas when the waste polymer compound is introduced. As a specific example of the compression screw conveyor, a length of 2,500 mm and a diameter of 300 mm is used. The length of the screw is 1,900mm and the pitch gap is compressed by reducing the pitch gap from 250mm to 180mm.

The pyrolysis body 30 is the most important part in terms of low temperature pyrolysis, and is designed in such a way that the screws installed therein are indirectly heated while rotating therein as shown in FIGS. 4 and 5.

As shown in FIG. 4 and FIG. 5, the pyrolysis body 30 is composed of three stages of cells, but may be variously modified and applied as necessary.

The pyrolysis body 30 is composed of a three-stage cell made of cast iron pipes connected to each other inside the pyrolysis body 30 to form a pyrolysis body 30, the transfer and compression screw conveyor 20 inside the pyrolysis body 30 Three transfer screws are installed as a means for transferring the waste polymer compound supplied through the low temperature pyrolysis by indirect heating.

The pyrolysis body 30 is heated by indirect heating by a burner (not shown) installed outside the lower end of the pyrolysis body 30.

In the pyrolysis body 30, volatilization reactions of materials occur during low-temperature pyrolysis, and the char generated during low-temperature pyrolysis is discharged through a pipe formed at one side of the pyrolysis body 30.

The heat source for low temperature pyrolysis in the pyrolysis body 30 is supplied through a burner installed at the bottom of each cell, and indirectly heats the material inside each cell through the burner. At this time, the internal temperature of the pyrolysis body 30 to maintain 400 ~ 700 ℃.

The external heat source supply uses LPG supplied from the LPG supply tank 100 in order to increase the temperature at the initial ignition, and after the generation of cracked gas which is non-condensable gas in the pyrolysis body 30, the recycle gas tank ( Recycle gas collected in the Recycle Gas Tank (70) is used as a heat source for heating the pyrolysis body (30).

As such, by reusing the regenerated gas collected in the recycle gas tank 70 as a heat source for heating the pyrolysis body 30, a cost reduction effect for low temperature pyrolysis can be obtained.

The non-condensed gas generated during the pyrolysis process is discharged to the outside at a pressure of 0.03 bar by a control blower, and the pressure in the pyrolysis body 30 is controlled using a valve.

The non-condensable gas circulating at 0.03 bar pressure by the control blower is scaled due to the generation of oil, tar and dust due to the temperature decrease of the pipe during the circulation of the pipe. Problems can cause blockage of the pipes.

Therefore, in order to solve such a problem, in the present invention, the first cyclone 401 and the second cyclone 402 are installed to remove tar and dust contained in the non-condensable gas in the first and second stages. .

Although the number of installation of the cyclone can be changed as necessary, it is preferable to configure two cyclones as described above. Figure 6 is to show an example of the technical configuration for explosion prevention of the low-temperature pyrolysis apparatus according to the present invention, the number of cyclones can be increased to a large number.

In addition to the tar and dust removal process through the cyclone 40, a screw is installed in the pipe from the pyrolysis body 30 to the inlet of the heat exchanger 50 at the rear end, and the pipe temperature is 220. By maintaining it in the range of ~ 400 ℃, it is possible to prevent the explosion of the low-temperature pyrolysis device while producing high-quality oil and gas by minimizing the generation of scale in the pipe and preventing the generation of oil (Fig. 6).

The pipe from the pyrolysis body 30 to the inlet of the heat exchanger 50 at the rear end is an elliptical shape rather than a circular shape. The long axis diameter of the oval is Φ400 and the short axis diameter is Φ250.

Inside the elliptical pipe is installed a screw having a rotational speed of 1,700 ~ 1,800rpm / min, wherein the total diameter of the screw to maintain Φ248.

The reason for forming the pipe in an elliptical shape is to allow the screw to rotate smoothly.

And, the blade of the screw is formed spirally, so that the angle between the plane and the wing perpendicular to the central axis of the screw to maintain 5 ~ 15 °.

In general, the blockage of the pipe in the pyrolysis facility occurs in the connection section between the pyrolysis body 30 and the cyclone 40 to remove dust, and the circulation of the gas due to the blockage phenomenon in the pipe in this section. If not done properly, the explosion may be caused by the sudden increase in gas pressure.

For this reason, in the present invention, it is possible to monitor the change in pressure by installing a pressure gauge on each of the pyrolysis body 30 and the cyclone 40, and the shape of the pipe is an elliptical pipe rather than a conventional circular pipe. To install the screw inside. At this time, the screw is driven at all times by a timer and configures a program to be driven when a differential pressure of a pressure gauge occurs.

The heat exchanger 50 condenses the tar and the dust-removed gas to oil through the cyclone 40, and the non-condensed gas that is not condensed goes to the next process. It will cycle.

And since the oil (Oil) is continuously discharged to the oil tank 90 by the level control (Level Control) does not affect the circulation of the non-condensed gas.

The non-condensable gas maintains the temperature at the inlet point entering the heat exchanger 50 at 220 ° C, and maintains the temperature at the outlet point exiting the heat exchanger 50 after heat exchange with the coolant is 60 ° C. Will be

In addition, the temperature at the inlet point at which the coolant enters the heat exchanger 50 is maintained at 20 ° C, and the temperature at the outlet point exiting the heat exchanger 50 after the heat exchange with the coolant is maintained at 25 ° C. do.

The gas condenser 60 cools and condenses the non-condensable gas that has passed through the heat exchanger 50 to generate oil, and then transfers the oil to the O-ring tank 90 installed at the rear end.

The non-condensed gas that has passed through the gas condenser 60 is collected in a recycle gas tank 70 at a later stage. The recycle gas tank 70 is a storage container for storing non-condensable gas generated during the low temperature pyrolysis process and reusing it as a heat source of a burner. The internal pressure of the recycle gas tank is maintained at 0.1 bar, and the internal pressure is controlled through a control valve.

The gas circulation device 80 is a device for circulating the gas stored in the recycle gas tank 70 to the pyrolysis body 30, as shown in FIG.

The gas circulation device 80 includes a gas filter 81 and a gas compression blower 82 in order to reuse the gas generated in the low temperature pyrolysis process.

Mist or the like remains in the collected gas and may be unsuitable for use as a heat source of the burner, so that the filter is filtered again using the gas filter 81.

In addition, the gas filtered by the gas filter 81 is quantitatively supplied at a pressure of 0.6 bar using the gas compression blower 82, and at this time, the pressure is regulated by a regulator to supply a burner in a constant pressure and quantitatively to a heat source. Will be reused.

The oil tank 90 is a device for storing the oil (Oil) generated from the heat exchanger and the gas condenser (50, 60), a specific example of the number of two, made of SS41 material. The specification is Φ3,600 × 3,800H or Φ2,600 × 3,600H and its capacity is 36m 3 or 18m 3.

Continuous low-temperature pyrolysis device having an explosion-proof function according to the present invention can be produced by using the waste oil in a safe state that does not occur explosion, so the stability is greatly improved and industrial applicability is large.

10: input hopper
20: conveying and compression screw conveyor
30: pyrolysis body
40: cyclone
50: heat exchanger
60: gas condenser
70: recycle gas tank
80: gas circulation device
90: oil tank
100: LPG Supply Tank

Claims (4)

An input hopper 10 for introducing waste polymer compounds,
In order to smoothly transport the waste polymer compound introduced through the inlet hopper 10 and to minimize the mixing with external oxygen, the feed and compression screw conveyor 20 is operated only by the conveyance and compression of the screw,
Pyrolysis body 30 for the low-temperature pyrolysis of the waste polymer compound supplied through the transfer and compression screw conveyor 20 by indirect heating while the screw rotates,
Cyclone 40 to remove tar and dust contained in the non-condensing gas generated from the pyrolysis body 30,
A heat exchanger 50 for condensing the non-condensable gas from which tar and dust are removed through the cyclone 40 to an oil, and transferring the non-condensable gas to an oil tank installed outside;
A gas condenser 60 for cooling and condensing the non-condensable gas that has passed through the heat exchanger 50 to an oil tank installed at the outside;
A recycle gas tank 70 for storing the non-condensable gas that has passed through the gas condenser 60 and reusing it as a heat source of the pyrolysis body 30;
A gas circulation device (80) for circulating the gas stored in the recycle gas tank (70) to a burner installed at a lower end of the pyrolysis body (30);
An oil tank 90 storing oil generated by the heat exchanger and the gas condenser 50 and 60;
LPG supply tank 100 for supplying the initial ignition heat source of the burner installed at the bottom of the pyrolysis body 30 to supply the LPG gas to the point of generation of decomposition gas,
In the low temperature pyrolysis apparatus in which a screw is installed in the pipe connected from the pyrolysis body 30 to the heat exchanger 50,
The pipe connected from the pyrolysis body 30 of the low temperature pyrolysis device to the heat exchanger 50 is an elliptical pipe whose internal temperature is maintained at 220 to 400 ° C., and the screw installed inside the elliptical pipe is 1,700 to 1,800 rpm / min. Having a rotational speed, wherein the blades of the screw are formed in a spiral shape and configured to maintain an angle between 5 and 15 ° between a wing perpendicular to the central axis of the screw and the blade;
The conveying and compressing screw conveyor 20 is a primary conveying and compressing screw conveyor 201 and a secondary conveying and compressing screw conveyor having an inclination of 30 to 40 degrees upward from the ground in the state connected to the feeding hopper 10. 202 is spoken to form a two-stage structure, connected to the pyrolysis body 30, and 2/10 to 3 of the total length of the secondary feed / compression screw conveyor 202 from the point where the pyrolysis body 30 is connected. Low temperature pyrolysis device having an explosion-proof function, characterized in that the compression zone is formed by forming a screw is not formed up to / 10.

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