Waste heat recycling system applicable to continuous pyrolysis facility

Abstract

The present invention relates to a waste heat recycling system applicable to a continuous pyrolysis facility, which can reduce a heat source by mixing high-temperature exhaust gas discharged after a pyrolysis reaction with air for burner combustion and re-supplying the exhaust gas to a burner for heating, maximize operation efficiency of plant facilities by heating and supplying water used in facilities producing steam such as hydrogen reforming facilities using high-temperature exhaust gas, or drying moisture in fuel by supplying the water to an outer wall of a fuel input hopper, and reduce an excessive supply amount of air supplied for combustion, thereby suppressing the generation of nitrogen oxides.

Description

Waste heat recycling system applicable to continuous pyrolysis facilities

[0001] The present invention relates to a waste heat recycling system applicable to a continuous pyrolysis facility, and more specifically, to a waste heat recycling system applicable to a continuous pyrolysis facility, which mixes high-temperature exhaust gas discharged after a pyrolysis reaction with burner combustion air and then re-supplies it to a heating burner to save a heating heat source, uses the high-temperature exhaust gas to heat and supply feed water used in a steam-producing facility such as a hydrogenation facility, or supplies it to the outer wall of a fuel input hopper to dry moisture in the fuel, thereby maximizing the operating efficiency of the plant facility, and further suppresses the production of nitrogen oxides by reducing the amount of excess air supplied for combustion.

[0002] Synthetic resin products like tires, vinyl, and plastics, widely used in various industries and daily life, are only recycled to a small extent after use. Most are classified as waste and are landfilled or incinerated. This synthetic resin waste is considerably larger in volume relative to its weight, making landfill costs higher than general waste. Furthermore, it does not decompose even after landfilling, making it a significant social nuisance.

[0003] Recently, research and development are actively underway on methods and devices for pyrolyzing synthetic resin waste to obtain useful oils, as a way to recycle such waste without incinerating or landfilling it.

[0004] In the past, there was no facility for recycling the high-temperature exhaust gas emitted after the pyrolysis reaction, and there was a problem of low energy efficiency because a separate heat source had to be supplied to heat the feed water used in steam-producing facilities such as hydrogen treatment facilities.

[0005] The present invention is intended to solve the above-mentioned problems, and to provide a waste heat recycling system applicable to a continuous pyrolysis facility, which mixes high-temperature exhaust gas discharged after a pyrolysis reaction with burner combustion air and then re-supplies it to a heating burner to save a heating heat source, uses the high-temperature exhaust gas to heat and supply feed water used in a steam-producing facility such as a hydrogenation facility, or supplies it to the outer wall of a fuel input hopper to detect moisture in the fuel, thereby maximizing the operating efficiency of the plant facility, and further suppresses the production of nitrogen oxides by reducing the excessive supply of air supplied for combustion.

[0006] A waste heat recycling system applicable to a continuous pyrolysis facility according to one embodiment of the present invention may include a heat resupply unit (110) that mixes exhaust gas discharged from a pyrolysis chamber with air and then resupplies it to the pyrolysis chamber, a water supply unit (120), and a water heating unit (130) that heats the water supplied from the water supply unit (120) using the heat of the heat resupply unit (110) and then supplies it to a hot water use process.

[0007] In one embodiment, the heat resupply unit (110) may include a gas suction fan (111) that sucks exhaust gas from a chimney extending from the pyrolysis chamber, an air suction fan (112) that sucks outside air, and a mixing unit (113) that mixes exhaust gas and air sucked through each of the gas suction fan (111) and the air suction fan (112).

[0008] In one embodiment, the heat resupply unit (110) may further include an air preheating unit (114) that mixes some of the exhaust gas sucked in through the gas suction fan (111) with the air sucked in through the air suction fan (112) and then supplies the mixture to the mixing unit (113).

[0009] In one embodiment, the heat resupply unit (110) may further include an electric valve (MOV) (115) installed in each of the gas suction fan (111), the air suction fan (112), the mixing unit (113) and the pipe connected to the pyrolysis chamber.

[0010] In one embodiment, the heat resupply unit (110) is installed in a chimney extended from the thermal decomposition chamber and further includes a nitrogen oxide measuring device (116) for measuring the amount of nitrogen oxide (NOx) emissions in exhaust gas, and the electric valve (115) can automatically adjust the opening / closing amount according to the measurement result of the nitrogen oxide emissions of the nitrogen oxide measuring device (116).

[0011] In one embodiment, the feedwater supply unit (120) may include a cooling water storage tank (121) for storing cooling water discharged from an oil cooling tower, a gas cooling tower, and a cooling water cooling tower, a cooling water circulation pump (122) for circulating the previously stored cooling water, a process feedwater storage tank (123) for storing cooling water discharged from the oil cooling tower, the gas cooling tower, and the cooling water cooling tower, and a feedwater supply pump (124) for supplying the previously stored feedwater toward the feedwater heating unit (130).

[0012] In one embodiment, when the hot water use process is not in operation, the water supply unit (120) operates the cooling water circulation pump (122) to circulate the cooling water stored in the cooling water storage tank (121) to the oil cooling tower, the gas cooling tower, the cooling water cooling tower, and the cooling water storage tank (121), and when the hot water use process is in operation, the cooling water circulation pump (122) to circulate the cooling water stored in the process water storage tank (123) to the oil cooling tower, the gas cooling tower, the cooling water cooling tower, and the process water storage tank (123) to recover heat and then supply the recovered heat to the water supply heating unit (130) through the water supply pump (124).

[0013] In one embodiment, the feedwater heating unit (130) heats the feedwater supplied through the feedwater supply pump (124) using the heat of the heat resupply unit (110) and supplies it to the hot water use process, and the heat used for heating the feedwater can be discharged to the outside through a chimney extended from the thermal decomposition chamber.

[0014] In one embodiment, a control valve (140) for controlling the supply amount of mixed air may be provided in the pipe connecting the mixing unit (113) and the pyrolysis chamber.

[0015] According to the present invention, the high temperature exhaust gas discharged after the pyrolysis reaction is mixed with burner combustion air and then re-supplied to the heating burner, thereby reducing the heating heat source, and the high temperature exhaust gas is used to heat and supply feed water used in the steam production of the hydrogenation facility, thereby having the advantage of maximizing the operating efficiency of the plant facility.

[0016] In addition, according to the present invention, there is an advantage in that the production of nitrogen oxides can be suppressed by reducing the excessive supply of air supplied for combustion.

[0017] FIG. 1 is a drawing showing the configuration of a waste heat recycling system (100) applicable to a continuous pyrolysis facility according to one embodiment of the present invention.

[0018] Figure 2 is a drawing showing the process of cooling water circulation when the hot water use process is not in operation.

[0019] Figure 3 is a drawing showing the process in which water is supplied to the water heating unit (130) through the water supply unit (120) when the hot water use process is in operation.

[0020] <Explanation of symbols>

[0021] 100: Waste heat recycling system applicable to continuous pyrolysis facilities

[0022] 110: Heat resupply unit 111: Gas intake fan

[0023] 112: Air intake fan 113: Mixing unit

[0024] 114: Air preheating unit 115: Electric valve

[0025] 116: Nitrogen oxide meter

[0026] 120: Water supply unit

[0027] 121: Coolant storage tank

[0028] 122: Coolant circulation pump

[0029] 123: Process water storage tank

[0030] 124: Water supply pump

[0031] 130: Water heating unit

[0032] 140: Control valve

[0033] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0034] In order to clearly explain the present invention, parts that are not related to the description are omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0035] In addition, in various embodiments, components having the same configuration are described only in representative embodiments using the same symbols, and in other embodiments, only configurations different from the representative embodiments are described.

[0036] Throughout the specification, when a part is said to be "connected" to another part, this includes not only "directly connected" but also "indirectly connected" with other elements intervening. Furthermore, when a part is said to "include" a component, this may mean that the other component is included, rather than excluded, unless otherwise specifically stated.

[0037]

[0038] FIG. 1 is a drawing showing the configuration of a waste heat recycling system (100) applicable to a continuous pyrolysis facility according to one embodiment of the present invention.

[0039] Referring to FIG. 1, a waste heat recycling system (100) applicable to a continuous pyrolysis facility according to one embodiment of the present invention may be largely configured to include a heat resupply unit (110), a water supply unit (120), and a water heating unit (130). In addition, in one embodiment, the system may further include a control valve (140) for controlling the amount of mixed air supplied to a heating burner within a pyrolysis chamber.

[0040] First, the heat resupply unit (110) plays a role in reducing the heating heat source by mixing the high-temperature exhaust gas discharged from the pyrolysis chamber with outside air and then resupplying it to the heating burner inside the pyrolysis chamber.

[0041] To this end, the heat resupply unit (110) may be configured to include a gas suction fan (111) that sucks exhaust gas from a chimney extended from a pyrolysis chamber, an air suction fan (112) that sucks outside air, and a mixing unit (113) that mixes exhaust gas and air sucked through each of the gas suction fan (111) and the air suction fan (112).

[0042] The gas suction fan (111) is connected to the chimney extended from the pyrolysis chamber through a pipe, and high-temperature exhaust gas is introduced through the pipe, and the introduction of exhaust gas is maximized by the gas suction fan (111). At this time, the introduction amount can be controlled by an electric valve (MOV) provided in the pipe. The high-temperature exhaust gas introduced through the gas suction fan (111) can be branched through a pipe connected to the rear and supplied to the mixing unit (113), the air preheating unit (114), the feedwater heating unit (130), and the fuel injection hopper.

[0043] The air intake fan (112) intakes outside air and supplies it to the mixing unit (113) through the air preheating unit (114). At this time, the air temporarily supplied to the air preheating unit (114) is first preheated by the high-temperature exhaust gas supplied through the gas intake fan (111) and then supplied to the mixing unit (113), thereby further reducing the heating heat source.

[0044] The mixing unit (113) serves to mix the high-temperature exhaust gas supplied through the gas suction fan (111) with the external air preheated primarily through the air preheating unit (114), and the high-temperature mixed air mixed by the mixing unit (113) is supplied to the heating burner of the pyrolysis chamber through the connected pipe. At this time, the supply amount of the mixed air can be controlled through the control valve (140).

[0045] An electric valve (MOV, 115) may be provided in each of the pipe connecting the gas suction fan (111) and the chimney, the pipe connecting the gas suction fan (111) and the mixing unit (113), the pipe branching from the gas suction fan (111) to the water supply heating unit (130), and the pipe branching from the gas suction fan (111) to the air preheating unit (114).

[0046] In addition, a nitrogen oxide measuring device (116) that measures the amount of nitrogen oxide (NOx) emitted from high-temperature exhaust gas is installed in the chimney of the thermal decomposition chamber, and the electric valve (115) installed in each pipe can automatically control the opening and closing amount according to the measurement result of the nitrogen oxide emitted from the nitrogen oxide measuring device (116).

[0047] This is to reduce nitrogen oxides generated during combustion by utilizing the low oxygen concentration in the exhaust gas, and can have the advantage of suppressing nitrogen oxide production by reducing the opportunity for nitrogen and oxygen to react by reducing the excess supply of combustion air.

[0048]

[0049] The water supply unit (120) supplies high-temperature water to the water heating unit (130) to produce steam for the hot water process corresponding to the hydrogen treatment facility. The water heating unit (130) heats the water using the heat supplied through the heat resupply unit (110) and then supplies it to the hot water process. The water supply situation of the water supply unit (120) changes depending on whether the hot water process is in operation or not, and this will be discussed as follows.

[0050] The feedwater supply unit (120) may be configured to include a cooling water storage tank (121) for storing cooling water discharged from an oil cooling tower, a gas cooling tower, and a cooling water cooling tower, a cooling water circulation pump (122) for circulating the previously stored cooling water, a process feedwater storage tank (123) for storing cooling water discharged from an oil cooling tower, a gas cooling tower, and a cooling water cooling tower, and a feedwater supply pump (124) for supplying the previously stored feedwater toward a feedwater heating unit (130).

[0051] Figure 2 is a drawing showing the process of cooling water circulation when the hot water use process is not in operation, and Figure 3 is a drawing showing the process of supplying water to the water supply heating unit (130) through the water supply unit (120) when the hot water use process is in operation.

[0052] First, looking at Figure 2, when the hot water use process is not in operation, the cooling water stored in the cooling water storage tank (121) is circulated through the cooling water circulation pump (122) to the oil cooling tower, gas cooling tower, cooling water cooling tower, and cooling water storage tank (121), thereby continuously cooling the oil cooling tower, gas cooling tower, and cooling water cooling tower.

[0053] At this time, since an electric valve is provided in the pipe through which cooling water is supplied to the process water storage tank (123), cooling water is prevented from being discharged to the process water storage tank (123) in the circulation process of FIG. 2.

[0054] Next, looking at Figure 3, first, when the hot water use process is in operation as shown in Figure 3(a), the water in the process water supply storage tank (123) is circulated to the process water supply storage tank (123) through the oil cooling tower and the gas cooling tower via the cooling water circulation pump (122), and then supplied to the water supply heating unit (130) via the water supply pump (124) as shown in Figure 3(b).

[0055] In this process, electric valves (MOV) are installed in all pipes connecting the water supply unit (120), and the opening and closing states of the electric valves can be individually controlled depending on the operating and non-operating status of the hot water use process.

[0056] In addition, in one embodiment, heat supplied through the heat resupply unit (110) can be supplied to the outer wall of the fuel input hopper to dry moisture in the fuel being input. In addition, at this time, an automatic temperature control valve can be provided on the pipe through which heat is supplied to the fuel input hopper to ensure that the heat supplied to the fuel input hopper is maintained at a preset temperature.

[0057] In addition, in one embodiment, the feedwater heating unit (130) heats the feedwater supplied through the feedwater supply pump (124) using the heat of the heat resupply unit (110) and supplies it to the hot water use process, and discharges the heat used for heating the feedwater to the outside through a chimney extended from the thermal decomposition chamber.

[0058]

[0059] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

[0060] According to the present invention, the high-temperature exhaust gas discharged after the pyrolysis reaction is mixed with burner combustion air and then re-supplied to the heating burner, thereby reducing the heating heat source. Therefore, the present invention is a technology that can be widely used in the pyrolysis industry to realize its practical and economic value.

Claims

1. A heat resupply unit (110) that mixes exhaust gas discharged from a pyrolysis chamber with air and then resupplies it to the pyrolysis chamber; Water supply unit (120); and A waste heat recycling system applicable to a continuous thermal decomposition facility, characterized by including a feed water heating unit (130) that heats feed water supplied from the feed water supply unit (120) using the heat of the heat resupply unit (110) and then supplies it to a hot water use process.

2. In paragraph 1, The above heat resupply unit (110) is A gas suction fan (111) for sucking exhaust gas from a chimney extended from the above pyrolysis chamber; An air intake fan (112) for sucking in outside air; and A waste heat recycling system applicable to a continuous pyrolysis facility, characterized in that it includes a mixing unit (113) that mixes exhaust gas and air sucked through each of the gas suction fan (111) and the air suction fan (112).

3. In paragraph 2, The above heat resupply unit (110) is A waste heat recycling system applicable to a continuous pyrolysis facility, characterized in that it further includes an air preheating unit (114) for mixing some of the exhaust gas sucked in through the gas suction fan (111) with the air sucked in through the air suction fan (112) and then supplying the mixture to the mixing unit (113).

4. In paragraph 3, The above heat resupply unit (110) is A waste heat recycling system applicable to a continuous pyrolysis facility, characterized in that it further includes an electric valve (MOV) (115) each installed in a pipe connected to the gas suction fan (111), the air suction fan (112), the mixing unit (113), and the pyrolysis chamber.

5. In paragraph 4, The above heat resupply unit (110) is It further includes a nitrogen oxide measuring device (116) installed in a chimney extended from the above thermal decomposition chamber and measuring the amount of nitrogen oxide (NOx) emissions in exhaust gas; A waste heat recycling system applicable to a continuous thermal decomposition facility, characterized in that the above electric valve (115) automatically controls the opening and closing amount according to the measurement result of the nitrogen oxide emission amount of the nitrogen oxide measuring device (116).

6. In paragraph 1, The above water supply unit (120) is A cooling water storage tank (121) for storing cooling water discharged from an oil cooling tower, a gas cooling tower, and a cooling water cooling tower; A cooling water circulation pump (122) that circulates stored cooling water; A process water storage tank (123) for storing cooling water discharged from the above oil cooling tower, gas cooling tower and cooling water cooling tower; and A waste heat recycling system applicable to a continuous pyrolysis facility, characterized in that it includes a feed water supply pump (124) that supplies stored feed water toward the feed water heating unit (130).

7. In paragraph 6, The above water supply unit (120) is When the above hot water usage process is not in operation, the cooling water circulation pump (122) is operated to circulate the cooling water stored in the cooling water storage tank (121) to the oil cooling tower, gas cooling tower, cooling water cooling tower, and cooling water storage tank (121). A waste heat recycling system applicable to a continuous pyrolysis facility, characterized in that when the above hot water use process is in operation, the cooling water circulation pump (122) is operated to circulate the feed water stored in the process feed water storage tank (123) to the oil cooling tower, gas cooling tower, cooling water cooling tower, and process feed water storage tank (123) to recover heat and then supply the recovered heat to the feed water heating unit (130) through the feed water supply pump (124).

8. In paragraph 6, The above water supply heating unit (130) is The water supplied through the above water supply pump (124) is heated using the heat of the heat resupply unit (110) and then supplied to the hot water use process. A waste heat recycling system applicable to a continuous pyrolysis facility, characterized in that the heat used for heating feedwater is discharged to the outside through a chimney extended from the pyrolysis chamber.

9. In paragraph 2, In the pipe connecting the above mixing unit (113) and the above thermal decomposition chamber, A waste heat recycling system applicable to a continuous pyrolysis facility, characterized in that a control valve (140) for controlling the supply amount of mixed air is provided.

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