A three-compartment back-blowing regenerative incinerator

Abstract

The present application relates to the field of heat accumulation type incinerator for treating industrial organic waste gas. A three-compartment reverse-blowing heat accumulation type incinerator comprises a combustion chamber, three heat accumulation chambers and a reverse-blowing system. Each heat accumulation chamber is provided with heat accumulation bodies, and each heat accumulation chamber has a heat accumulation channel passing through the heat accumulation bodies. Each heat accumulation channel is connected to the combustion chamber through a gas inlet / exhaust pipe with a reversing valve at one end, and at the other end, each heat accumulation channel is connected to a waste gas inlet pipe with a gas inlet valve, an exhaust pipe with an exhaust valve and a reverse-blowing pipe with a reverse-blowing valve, respectively. The waste gas inlet pipe is connected to a main waste gas pipe, the exhaust pipe is connected to a main exhaust pipe, and the reverse-blowing pipe is connected to a main reverse-blowing pipe, which is connected to a reverse-blowing fan. During use, the three heat accumulation chambers are alternately cycled for gas inlet, reverse blowing and exhaust. When one of the heat accumulation chambers is used for gas inlet, the other two are used for reverse blowing and exhaust, respectively. The heat accumulation channels of each heat accumulation chamber are cycled for gas inlet, reverse blowing and exhaust.

Description

Technical Field

[0001] This invention relates to the field of regenerative thermal ignition (RTI) incinerators for treating industrial organic waste gas. Background Technology

[0002] Regenerative thermal oxidizers (RTOs) are effective devices for treating industrial organic waste gas. However, in traditional two-compartment RTOs, untreated waste gas remaining in the current regenerator chamber is directly released into the atmosphere during valve switching, causing instantaneous exceedances of pollutant emissions, and making it difficult to consistently achieve an organic matter removal rate of over 99.5%. Furthermore, existing technologies generally suffer from the following problems: Uneven airflow distribution: This leads to localized overheating or underheating of the heat storage body, resulting in decreased heat exchange efficiency and easy damage to the ceramic body.

[0003] Poor valve sealing: Traditional butterfly valves are prone to wear under frequent switching, leading to exhaust gas leakage, which affects treatment efficiency and the environment.

[0004] The heat storage medium is prone to clogging: When treating waste gas containing ammonia, hydrogen cyanide and other components, solid crystals such as ammonium salts will be generated in the temperature range of around 200℃, which will block the honeycomb channels and increase the system resistance.

[0005] Insufficient safety: Explosion-proof doors have slow response and poor sealing, and the interlocking protection of the control system is inadequate, posing risks of explosion and poisoning.

[0006] Energy efficiency needs improvement: Poor design of indirect heat exchange or heat storage structure leads to low heat recovery efficiency and high operating fuel costs. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to address the issues mentioned in the background art, such as uneven airflow distribution, poor valve sealing, easy blockage of the heat storage body, insufficient safety, and the need to improve energy efficiency in regenerative incinerators.

[0008] The technical solution adopted in this invention is as follows: a three-compartment reverse-flushing regenerative incinerator, comprising a combustion chamber, a regenerator chamber, and a reverse-flushing system. There are three regenerator chambers, each equipped with a regenerator body. Each regenerator chamber has a regenerator channel passing through the regenerator body. One end of each regenerator channel is connected to the combustion chamber via an inlet / exhaust pipe with a reversing valve. The other end of each regenerator channel is connected to an exhaust gas inlet pipe with an inlet valve, an exhaust pipe with an exhaust valve, and a reverse-flushing pipe with a reverse-flushing valve. The exhaust gas inlet pipe is connected to the main exhaust pipe, the exhaust pipe to the main exhaust pipe, and the reverse-flushing pipe to the main reverse-flushing pipe, which is connected to a reverse-flushing blower. During operation, the three regenerator chambers alternately cycle through inlet, reverse-flushing, and exhaust. When one regenerator chamber is inlet, the other two are either reverse-flushing or exhausting. The regenerator channel in each regenerator chamber cycles through inlet, reverse-flushing, and exhaust. When a regenerator chamber is inlet, the inlet valve is open, and the exhaust valve and reverse-flushing valve are closed. When the reversing valve reverses, gas from the intake / exhaust pipe can only enter the combustion chamber, while organic waste gas enters the heat storage channel, absorbing heat from the heat storage medium in the heat storage chamber. The temperature rises to 760℃–850℃ before entering the combustion chamber. Under high temperature and sufficient oxygen conditions, the organic waste gas undergoes an oxidation reaction, decomposing into carbon dioxide and water vapor. When the heat storage chamber is backflushed, the backflushing valve opens, and the intake valve and exhaust valve close. Gas from the intake / exhaust pipe can only enter the combustion chamber. The backflushing gas carries the untreated waste gas remaining inside the heat storage chamber into the combustion chamber, preventing the emission of untreated waste gas remaining inside the heat storage chamber when the intake is directly switched to exhaust. When the heat storage chamber is exhausting, the exhaust valve opens, and the backflushing valve and intake valve close. The reversing valve reverses, allowing gas from the intake / exhaust pipe to enter only the heat storage chamber. Carbon dioxide and water vapor from the combustion chamber enter the heat storage channel, heating the heat storage medium in the heat storage chamber. After the temperature drops to a dischargeable level, the gas is discharged through the exhaust pipe.

[0009] The reversing valve is a poker-style three-way valve, which includes a main channel and two branch channels. The main channel is connected to the heat storage chamber, and the two branch channels are connected to the combustion chamber. When one branch channel is connected, the other branch channel is closed. Each branch channel is a controllable one-way valve channel. Each one-way valve channel is opened / closed by controlling a stainless steel valve plate and the sealing ring to be either closed or uncovered.

[0010] The heat storage element is a honeycomb ceramic heat storage element with straight-through square holes, with external dimensions of 150mm×150mm×300mm / 150mm. The lower layer uses dense cordierite with 25 holes × 25 holes, which has good corrosion resistance; the upper layer uses high-alumina material with 40 holes × 40 holes, which has strong heat storage capacity. The heat storage element support surface uses a specially designed saddle ring packing layer (150mm high, made of SUS316L) and support bracket. The saddle ring packing layer can effectively buffer airflow, making the distribution more uniform, and at the same time, it can intercept and contain some aerosols and ammonium salt crystals, alleviating their blockage of the upper honeycomb ceramic. The support frame is made of SUS316L stainless steel wire mesh, which has good air permeability and uniform load-bearing capacity.

[0011] The main exhaust gas pipe is connected to the air distribution box, which is connected to the swirl plate distributor. The swirl plate distributor causes the incoming gas to swirl, breaking the laminar flow state, so that the exhaust gas can be evenly distributed in the cross-section when it enters the bottom of the heat storage chamber. The swirl plate distributor is connected to the exhaust gas source pipe through a high-efficiency demister and an exhaust gas water washing tower. The exhaust gas in the exhaust gas source pipe passes through the exhaust gas water washing tower and the high-efficiency demister to remove alkaline mist, residual dust and water vapor from the exhaust gas.

[0012] An explosion-proof door is installed on the top of the combustion chamber. The explosion-proof door is connected to the exhaust pipe after the reversing valve. The explosion-proof door releases the instantaneous overpressure gas caused by the deflagration of exhaust gas into the exhaust pipe.

[0013] A temperature sensor is installed in the combustion chamber. When the temperature is detected to be below 880°C, the burner will automatically ignite. When the temperature is detected to be above 950°C, the system will alarm. When the temperature is detected to be above 980°C, the fuel supply will be automatically cut off, that is, the valve for the gas entering the combustion chamber from the regenerator will be disconnected.

[0014] The main exhaust pipe is equipped with at least two combustible gas concentration detectors, with two alarm levels: when the LEL is 15%, the first alarm is triggered, with an audible and visual alarm and an increase in air intake; when the LEL is 20%, the second alarm is triggered, the interlocked emergency bypass valve opens, and the exhaust gas is directly discharged to the chimney, cutting off the path to the combustion chamber.

[0015] Compared with existing technologies, the significant advantages of this invention are: extremely high processing efficiency: the three-chamber backflushing process completely eliminates exhaust gas escape during valve switching, ensuring a stable VOCs removal rate of over 99.9%. Excellent energy-saving effect: the combination of patented honeycomb heat storage and swirl distribution technology achieves a system heat recovery efficiency of ≥95%, resulting in extremely low natural gas consumption during normal operation when treating low-concentration exhaust gases (approximately 30 Nm³ / h at a flow rate of 30,000 Nm³ / h). Outstanding reliability: the poker-style valve and anti-clogging heat storage structure significantly reduce maintenance frequency and failure rate, ensuring long-term stable system operation. Comprehensive safety: from concentration warning, flame monitoring, over-temperature and over-pressure protection to explosion-proof pressure relief and emergency shutdown, a multi-layered, redundant safety protection system is constructed, making it particularly suitable for treating complex exhaust gases containing corrosive and toxic substances. Wide adaptability: Special pretreatment and anti-corrosion design enable it to treat waste gas containing halogens, sulfur, phosphorus, arsenic and other substances that are toxic to catalysts, as well as ammonia-containing waste gas that easily produces ammonium salts, making its application range far exceed that of catalytic oxidation furnaces. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2This is a schematic diagram of the poker-style three-way valve structure of the present invention. Detailed Implementation

[0017] like Figure 1 As shown, a three-compartment reverse-flushing regenerative incinerator includes a combustion chamber, a regenerator chamber, and a reverse-flushing system. There are three regenerator chambers, each equipped with a regenerator. Each regenerator chamber has a regenerator channel that passes through the regenerator. One end of each regenerator channel is connected to the combustion chamber via an inlet / exhaust pipe with a reversing valve. The other end of each regenerator channel is connected to an exhaust gas inlet pipe with an inlet valve, an exhaust pipe with an exhaust valve, and a reverse-flushing pipe with a reverse-flushing valve. The exhaust gas inlet pipe is connected to the exhaust main pipe, the exhaust pipe is connected to the exhaust main pipe, the reverse-flushing pipe is connected to the reverse-flushing main pipe, and the reverse-flushing main pipe is connected to the reverse-flushing blower.

[0018] The reversing valve is a poker-style three-way valve, which includes a main channel and two branch channels. The main channel is connected to the heat storage chamber, and the two branch channels are connected to the combustion chamber. When one branch channel is connected, the other branch channel is closed. Each branch channel is a controllable one-way valve channel. Each one-way valve channel is opened / closed by controlling a stainless steel valve plate and the sealing ring to be either closed or uncovered.

[0019] The heat storage body adopts a honeycomb ceramic heat storage body with straight square holes, with external dimensions of 150mm×150mm×300mm / 150mm. The lower layer uses dense cordierite with 25 holes × 25 holes, which has good corrosion resistance; the upper layer uses high-alumina material with 40 holes × 40 holes, which has strong heat storage capacity. The heat storage body support surface adopts a specially designed saddle ring packing layer (150mm high, material is SUS316L) and support bracket. The saddle ring packing layer can effectively buffer the airflow, making the distribution more uniform. At the same time, it can intercept and contain some aerosols and ammonium salt crystals, which can alleviate their blockage of the upper honeycomb ceramic. The support bracket uses SUS316L stainless steel wire mesh, which has good air permeability and uniform load bearing.

[0020] The main exhaust gas pipe is connected to the air distribution box, which is connected to the swirl plate distributor. The swirl plate distributor causes the incoming gas to swirl, breaking the laminar flow state, so that the exhaust gas can be evenly distributed in the cross-section when it enters the bottom of the heat storage chamber. The swirl plate distributor is connected to the exhaust gas source pipe through a high-efficiency demister and an exhaust gas water washing tower. The exhaust gas in the exhaust gas source pipe passes through the exhaust gas water washing tower and the high-efficiency demister to remove alkaline mist, residual dust and water vapor from the exhaust gas.

[0021] An explosion-proof door is installed on the top of the combustion chamber. The explosion-proof door is connected to the exhaust pipe after the reversing valve. The explosion-proof door releases the instantaneous overpressure gas caused by the deflagration of exhaust gas into the exhaust pipe.

[0022] A temperature sensor is installed in the combustion chamber. When the temperature is detected to be below 880°C, the burner will automatically ignite. When the temperature is detected to be above 950°C, the system will alarm. When the temperature is detected to be above 980°C, the fuel supply will be automatically cut off, that is, the valve for the gas entering the combustion chamber from the regenerator will be disconnected.

[0023] The main exhaust pipe is equipped with at least two combustible gas concentration detectors, with two alarm levels: when the LEL is 15%, the first alarm is triggered, with an audible and visual alarm and an increase in air intake; when the LEL is 20%, the second alarm is triggered, the interlocked emergency bypass valve opens, and the exhaust gas is directly discharged to the chimney, cutting off the path to the combustion chamber.

[0024] During operation, the three heat storage chambers alternately cycle through air intake, backflushing, and exhaust. When one heat storage chamber is intake, the other two are either backflushing or exhausting. Each heat storage chamber's heat storage channel cycles through these processes. When a heat storage chamber is intake, the intake valve opens, while the exhaust valve and backflushing valve close. The reversing valve then reverses direction, allowing only the combustion chamber to receive gas from the intake / exhaust pipes. Organic waste gas enters the heat storage channel, absorbing heat from the heat storage medium in the heat storage chamber, raising its temperature to 760℃–850℃. Upon entering the combustion chamber, under high temperature and sufficient oxygen conditions, the organic waste gas undergoes an oxidation reaction and is decomposed into carbon dioxide. When the regenerator is backflushed, the backflushing valve opens, and the intake valve and exhaust valve close. Gas in the intake / exhaust pipe can only enter the combustion chamber. The backflushing gas carries the untreated exhaust gas remaining inside the regenerator into the combustion chamber, preventing the emission of untreated exhaust gas remaining inside the regenerator when the intake is directly switched to exhaust. When the regenerator is exhausting, the exhaust valve opens, the backflushing valve and intake valve close, and the reversing valve reverses. Gas in the intake / exhaust pipe can only enter the regenerator. Carbon dioxide and water vapor in the combustion chamber enter the regenerator channel to heat the regenerator in the regenerator. After the temperature drops to a dischargeable level, it is discharged through the exhaust pipe.

[0025] In one embodiment, the exhaust gas parameters are: Source: Cold drums in the South and North areas, and various storage tanks for stored tar.

[0026] Ingredients: benzo[a]pyrene, benzene, ammonia, hydrogen cyanide, hydrocarbons, etc.

[0027] Concentration: ~1000mg / Nm³, calorific value: ~10Kcal / Nm³.

[0028] Pretreatment: Existing oil washing, acid washing, and alkali washing processes are followed by entry into this system.

[0029] System startup: First, close all exhaust gas inlet valves and open the exhaust valve. The burner will automatically ignite and preheat the three regenerators to the operating temperature (approximately 850°C).

[0030] Normal operation: Cycle 1 (0-2 minutes): The exhaust gas passes through the exhaust gas fan → water washing tower → demister → flame arrester → exhaust gas main pipe → first heat storage chamber and is preheated to 850℃.

[0031] After preheating, the exhaust gas enters the combustion chamber and is heated to over 900°C with the assistance of the burner. It stays for more than 1.2 seconds, during which the organic matter is completely decomposed.

[0032] The high-temperature purified flue gas (mainly carbon dioxide and water) in the combustion chamber enters the third regenerator, which heats the regenerator in the third regenerator. The temperature of the regenerator rises to above 850°C. After the temperature of the purified flue gas drops to an emission level (such as 70°C), it is discharged through the exhaust pipe.

[0033] After a portion of the purified flue gas is extracted and mixed with air, the second regenerator is purged to remove residual exhaust gas. The purging gas then enters the combustion chamber, providing some air to the combustion chamber. By controlling the proportion of purified flue gas (calculated as carbon dioxide), the oxygen concentration in the combustion chamber can be controlled.

[0034] Cycle 2 (2-4 minutes): Valve switching, process changes to: The exhaust gas passes through the exhaust gas fan → water washing tower → demister → flame arrester → exhaust gas main pipe → third heat storage chamber and is preheated to 850℃.

[0035] After preheating, the exhaust gas enters the combustion chamber and is heated to over 900°C with the assistance of the burner. It stays for more than 1.2 seconds, during which the organic matter is completely decomposed.

[0036] The high-temperature purified flue gas (mainly carbon dioxide and water) in the combustion chamber enters the second regenerator, which heats the regenerator in the second regenerator. The temperature of the regenerator rises to above 850°C. After the temperature of the purified flue gas drops to an emission level (such as 70°C), it is discharged through the exhaust pipe.

[0037] After a portion of the purified flue gas is extracted and mixed with air, the first regenerator chamber is purged to remove residual exhaust gas. The purging gas then enters the combustion chamber, providing it with a portion of the air. By controlling the proportion of purified flue gas (measured as carbon dioxide), the oxygen concentration in the combustion chamber can be controlled.

[0038] Cycle 3 (4-6 minutes): The process becomes: The exhaust gas passes through an exhaust gas fan → water washing tower → demister → flame arrester → exhaust gas main pipe → second heat storage chamber, where it is preheated to 850℃.

[0039] After preheating, the exhaust gas enters the combustion chamber and is heated to over 900°C with the assistance of the burner. It stays for more than 1.2 seconds, during which the organic matter is completely decomposed.

[0040] The high-temperature purified flue gas (mainly carbon dioxide and water) in the combustion chamber enters the first regenerator chamber, which heats the regenerator in the second regenerator chamber. The temperature of the regenerator rises to above 850°C. After the temperature of the purified flue gas drops to an emission level (such as 70°C), it is discharged through the exhaust pipe.

[0041] After a portion of the purified flue gas is extracted and mixed with air, the third regenerator is purged to remove residual exhaust gas. The purging gas then enters the combustion chamber, providing some air to the combustion chamber. By controlling the proportion of purified flue gas (calculated as carbon dioxide), the oxygen concentration in the combustion chamber can be controlled.

[0042] The cycle repeats in a 1-cycle manner.

[0043] Security monitoring: The main exhaust pipe is equipped with at least two combustible gas concentration detectors, and the PLC monitors all temperature, pressure, and concentration signals in real time. Two alarm levels are set: at 15% LEL, a level one alarm is triggered, with audible and visual alarms and an increase in air intake; at 20% LEL, a level two alarm is triggered, the interlocking emergency bypass valve opens, and the exhaust gas is directly discharged to the chimney, cutting off the path to the combustion chamber.

Claims

1. A three-compartment reverse-flushing regenerative incinerator, characterized in that: The system includes a combustion chamber, a regenerator chamber, and a backflushing system. There are three regenerator chambers, each equipped with a heat storage body. Each chamber has a heat storage channel running through the heat storage body. One end of each heat storage channel connects to the combustion chamber via an intake / exhaust pipe with a reversing valve. The other end of each heat storage channel connects to an exhaust gas intake pipe with an intake valve, an exhaust pipe with an exhaust valve, and a backflushing pipe with a backflushing valve. The exhaust gas intake pipe connects to the main exhaust pipe, the exhaust pipe connects to the main exhaust pipe, and the backflushing pipe connects to the main backflushing pipe, which in turn connects to a backflushing blower. During operation, the three regenerator chambers alternately cycle through intake, backflushing, and exhaust. When one regenerator chamber is intake, the other two are either backflushing or exhausting. Each regenerator chamber's heat storage channel cycles through these processes. When a regenerator chamber is intake, the intake valve opens, the exhaust valve and backflushing valve close, the reversing valve reverses, and the intake / exhaust pipe... The gas in the combustion chamber can only enter the combustion chamber, while the organic waste gas enters the heat storage channel, absorbing heat from the heat storage body in the heat storage chamber. The temperature rises to 760℃–850℃, and then enters the combustion chamber. Under high temperature and sufficient oxygen conditions, the organic waste gas undergoes an oxidation reaction and is decomposed into carbon dioxide and water vapor. When the heat storage chamber is backflushed, the backflushing valve opens, and the intake valve and exhaust valve close. The gas in the intake / exhaust pipe can only enter the combustion chamber. The backflushing gas carries the untreated waste gas remaining inside the heat storage chamber into the combustion chamber, preventing the emission of untreated waste gas remaining inside the heat storage chamber when the intake is directly switched to the exhaust. When the heat storage chamber is exhausting, the exhaust valve opens, the backflushing valve and intake valve close, and the reversing valve reverses. The gas in the intake / exhaust pipe can only enter the heat storage chamber. The carbon dioxide and water vapor in the combustion chamber enter the heat storage channel, heating the heat storage body in the heat storage chamber. After the temperature drops to an acceptable level, it is discharged through the exhaust pipe.

2. The three-compartment reverse-flushing regenerative incinerator according to claim 1, characterized in that: The reversing valve is a poker-style three-way valve, which includes a main channel and two branch channels. The main channel is connected to the heat storage chamber, and the two branch channels are connected to the combustion chamber. When one branch channel is connected, the other branch channel is closed. Each branch channel is a controllable one-way valve channel. Each one-way valve channel is opened / closed by controlling a stainless steel valve plate and the sealing ring to be either closed or uncovered.

3. The three-compartment reverse-flushing regenerative incinerator according to claim 1, characterized in that: The heat storage body adopts a honeycomb ceramic heat storage body with straight square holes, with external dimensions of 150mm×150mm×300mm / 150mm. The lower layer uses dense cordierite with 25 holes × 25 holes, which has good corrosion resistance; the upper layer uses high-alumina material with 40 holes × 40 holes, which has strong heat storage capacity. The heat storage body support surface adopts a specially designed saddle ring packing layer and support bracket. The saddle ring packing layer can effectively buffer the airflow, making the distribution more uniform, and can also intercept and contain some aerosols and ammonium salt crystals, alleviating their blockage of the upper honeycomb ceramic. The support bracket uses SUS316L stainless steel wire mesh, which has good air permeability and uniform load bearing.

4. The three-compartment reverse-flushing regenerative incinerator according to claim 1, characterized in that: The main exhaust gas pipe is connected to the air distribution box, which is connected to the swirl plate distributor. The swirl plate distributor causes the incoming gas to swirl, breaking the laminar flow state, so that the exhaust gas can be evenly distributed in the cross-section when it enters the bottom of the heat storage chamber. The swirl plate distributor is connected to the exhaust gas source pipe through a high-efficiency demister and an exhaust gas water washing tower. The exhaust gas in the exhaust gas source pipe passes through the exhaust gas water washing tower and the high-efficiency demister to remove alkaline mist, residual dust and water vapor from the exhaust gas.

5. A three-compartment reverse-flushing regenerative incinerator according to claim 1, characterized in that: An explosion-proof door is installed on the top of the combustion chamber. The explosion-proof door is connected to the exhaust pipe after the reversing valve. The explosion-proof door releases the instantaneous overpressure gas caused by the deflagration of exhaust gas into the exhaust pipe.

6. The three-compartment reverse-flushing regenerative incinerator according to claim 1, characterized in that: A temperature sensor is installed in the combustion chamber. When the temperature is detected to be below 880°C, the burner will automatically ignite. When the temperature is detected to be above 950°C, the system will alarm. When the temperature is detected to be above 980°C, the fuel supply will be automatically cut off, that is, the valve for the gas entering the combustion chamber from the regenerator will be disconnected.

7. A three-compartment reverse-flushing regenerative incinerator according to claim 1, characterized in that: The main exhaust pipe is equipped with at least two combustible gas concentration detectors, with two alarm levels: when the LEL is 15%, the first alarm is triggered, with an audible and visual alarm and an increase in air intake; when the LEL is 20%, the second alarm is triggered, the interlocked emergency bypass valve opens, and the exhaust gas is directly discharged to the chimney, cutting off the path to the combustion chamber.

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