Non-contact heat accumulating type thermal oxidation furnace

Abstract

The utility model discloses a non-contact heat accumulating type thermal oxidation furnace which comprises a thermal oxidation furnace outer box, a first heat exchanger, a second heat exchanger, a pyrolysis cavity and a natural gas burner, according to the thermal oxidation furnace, the first heat exchanger and the second heat exchanger are matched with each other to exchange heat energy, so that waste gas is heated twice before entering the pyrolysis cavity, then the waste gas is subjected to thorough thermal decomposition through the natural gas burner, and the temperature of purified gas obtained after thermal decomposition is subjected to heat exchange, so that the energy-saving effect is achieved; and the thermal oxidation furnace adopts a single-box structure, so that the structural design occupies a small space, and transportation and on-site arrangement are convenient.

Description

Technical Field

[0001] This utility model belongs to the technical field of waste gas treatment equipment, and in particular relates to a non-contact regenerative thermal oxidizer. Background Technology

[0002] A Regenerative Thermal Oxidizer (RTO) is a highly efficient waste gas treatment device, primarily used to treat volatile organic compounds (VOCs) emitted from industrial processes. It decomposes VOCs into harmless carbon dioxide (CO2) and water (H2O) through high-temperature oxidation, while simultaneously recovering heat using a heat storage medium, significantly improving energy efficiency. Common RTOs include multi-bed (chamber) RTOs and rotary RTOs. A multi-bed (chamber) RTO is a regenerative incineration device with a multi-chamber structure, achieving efficient heat recovery and VOCs treatment through the cyclic switching of multiple heat storage chambers. A rotary RTO, on the other hand, uses a rotating structure, relying on a turntable to switch airflow between different functional zones to achieve heat recovery and VOCs decomposition.

[0003] However, the design of multi-bed (compartment) RTOs still has some problems: 1) The valves of multiple heat storage chambers switch frequently and are subjected to high temperature and frequency shocks, which can easily lead to wear, jamming or sealing failure, resulting in exhaust gas leakage, heat loss or equipment shutdown; 2) Thermal stress caused by temperature difference may lead to thermal stress accumulation during long-term operation, causing component deformation or damage, reducing equipment life or causing safety hazards; 3) The equipment of multiple heat storage chambers is large in size and occupies a lot of space, which makes installation difficult for companies with limited space; 4) When the exhaust gas composition is complex, it may deposit on the surface of the heat storage body, causing blockage of the heat storage body or reduced heat exchange efficiency, requiring frequent cleaning and increasing operating costs.

[0004] Although rotary RTOs are compact and efficient, they also have some unique problems: 1) After long-term operation, the sealing components of the rotating parts are prone to wear or failure, which can easily lead to exhaust gas leakage or reduced efficiency; 2) Long-term operation of the drive system may cause problems such as bearing wear and motor overload, affecting the normal operation of the equipment; 3) The thermal efficiency fluctuates greatly, and if the design or control is not proper, it may lead to uneven heat recovery; 4) Rotary RTOs have certain restrictions on the composition of exhaust gas. Exhaust gas containing particulate matter or sticky substances may cause scaling or damage to the rotating surface; 5) The structure is relatively complex, and maintenance requires disassembly of the rotating parts, which increases the difficulty and time of maintenance. Utility Model Content

[0005] To address the deficiencies in the aforementioned background technology, the purpose of this utility model is to provide a non-contact regenerative thermal oxidizer. This thermal oxidizer adopts a single-box structure, which has a small footprint and is convenient for transportation and on-site placement.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A non-contact regenerative thermal oxidizer includes an outer casing, a first heat exchanger, a second heat exchanger, a pyrolysis chamber, and a natural gas burner. The first heat exchanger, the second heat exchanger, the pyrolysis chamber, and the natural gas burner are all installed inside the outer casing. The first heat exchanger and the second heat exchanger are spaced apart and interconnected. The pyrolysis chamber is located on top of the second heat exchanger and is connected to it. The natural gas burner is located on one side of the pyrolysis chamber and is connected to it.

[0008] As a further description of the above technical solution, a first connecting pipe and a second connecting pipe are provided between the first heat exchanger and the second heat exchanger at an interval.

[0009] As a further description of the above technical solution, the first heat exchanger is provided with a first air inlet pipe and a first air outlet pipe on its side and bottom, respectively.

[0010] As a further description of the above technical solution, the second heat exchanger is provided with a second air inlet pipe and a second air outlet pipe on its side and bottom, respectively.

[0011] As a further description of the above technical solution, a pyrolysis inlet pipe and a pyrolysis outlet pipe are provided at intervals between the pyrolysis chamber and the second heat exchanger.

[0012] As a further description of the above technical solution, the side of the pyrolysis chamber near the second heat exchanger is lined with heat storage packing.

[0013] As a further description of the above technical solution, the first heat exchanger, the second heat exchanger and the pyrolysis chamber all use a double-layer shell, with flame-retardant and heat-insulating material filling the space between the layers.

[0014] The beneficial effects of this utility model are as follows:

[0015] (1) The non-contact regenerative thermal oxidizer of this utility model includes a thermal oxidizer outer casing, a first heat exchanger, a second heat exchanger, a pyrolysis chamber and a natural gas burner. Specifically, the first heat exchanger and the second heat exchanger work together to exchange heat energy, so that the waste gas is heated twice before entering the pyrolysis chamber, and then thoroughly thermally decomposed by the natural gas burner. The reaction temperature during the thermal decomposition process can reach >900℃. When the waste gas concentration is sufficient, it can sustain combustion and use the temperature of the purified gas after thermal decomposition for heat exchange, so as to achieve energy saving effect.

[0016] (2) The non-contact regenerative thermal oxidizer of this utility model adopts a single-box structure, which occupies little space and is convenient for transportation and on-site placement; the switching process of multiple boxes is omitted, avoiding temperature fluctuations when switching multiple boxes, and the exhaust gas can be stably decomposed to ensure stable emission standards; at the same time, the structure adopts a zero-valve design, which can avoid valve wear, opening and closing failure, leakage, and insulation problems. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the internal structure of the non-contact regenerative thermal oxidation furnace of this utility model;

[0018] Figure 2 This is a schematic diagram of gas flow in the first application form of the non-contact regenerative thermal oxidizer of this utility model;

[0019] Figure 3 This is a schematic diagram of gas flow in the second application form of the non-contact regenerative thermal oxidizer of this utility model.

[0020] In the figure, 1 is the outer casing of the thermal oxidizer, 2 is the first heat exchanger, 3 is the second heat exchanger, 4 is the pyrolysis chamber, 5 is the natural gas burner, 6 is the first connecting pipe, 7 is the second connecting pipe, 8 is the first air inlet pipe, 9 is the first air outlet pipe, 10 is the second air inlet pipe, 11 is the second air outlet pipe, 12 is the pyrolysis air inlet pipe, 13 is the pyrolysis air outlet pipe, and 14 is the heat storage packing. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] As attached Figure 1-3 As shown in the embodiment of this utility model, a non-contact regenerative thermal oxidizer includes a thermal oxidizer outer casing 1, a first heat exchanger 2, a second heat exchanger 3, a pyrolysis chamber 4, and a natural gas burner 5. The first heat exchanger 2, the second heat exchanger 3, the pyrolysis chamber 4, and the natural gas burner 5 are all installed inside the thermal oxidizer outer casing 1. The first heat exchanger 2 and the second heat exchanger 3 are spaced apart and interconnected. The pyrolysis chamber 4 is located on top of the second heat exchanger 3 and is connected to it. The natural gas burner 5 is located on one side of the pyrolysis chamber 4 and is connected to it.

[0023] Specifically, the first heat exchanger 2 is a stainless steel plate heat exchanger, which has a compact structure and a high conductivity coefficient; the second heat exchanger 3 is a heat exchanger made of high-temperature resistant materials such as 310s stainless steel, silicon carbide or ceramics, which has excellent high-temperature resistance, oxidation resistance, corrosion resistance and heat transfer performance.

[0024] In the first heat exchanger 2 and the second heat exchanger 3, the high-temperature fluid flowing in one side of the channel transfers heat to the low-temperature fluid flowing in the other side of the channel through the plates (or walls), thereby achieving heat exchange; the first heat exchanger 2 achieves the first stage of heat energy exchange, and the second heat exchanger 3 achieves the second stage of heat energy exchange.

[0025] A first connecting pipe 6 and a second connecting pipe 7 are provided between the first heat exchanger 2 and the second heat exchanger 3 at intervals, and the first heat exchanger 2 and the second heat exchanger 3 are connected through the first connecting pipe 6 and the second connecting pipe 7 respectively.

[0026] The first heat exchanger 2 is provided with a first air inlet pipe 8 and a first air outlet pipe 9 on its side and bottom, respectively; the second heat exchanger 3 is provided with a second air inlet pipe 10 and a second air outlet pipe 11 on its side and bottom, respectively.

[0027] The pyrolysis chamber 4 and the second heat exchanger 3 are connected by a pyrolysis inlet pipe 12 and a pyrolysis outlet pipe 13 at intervals, respectively, which connect the pyrolysis chamber 4 and the second heat exchanger 3.

[0028] The pyrolysis chamber 4 is provided with a heat storage packing 14 on the side close to the second heat exchanger 3. The heat storage packing 14 can be a honeycomb ceramic heat storage body, which is located at the air inlet and air outlet of the pyrolysis chamber 4. It has the functions of heat isolation and heat storage, thereby maintaining the temperature in the pyrolysis chamber 4.

[0029] The first heat exchanger 2, the second heat exchanger 3 and the pyrolysis chamber 4 all use double-layer shells, with flame-retardant and heat-insulating material filling the space between the layers.

[0030] The working principle of this non-contact regenerative thermal oxidizer is as follows:

[0031] 1. Reference Figure 2 In a specific embodiment of this utility model, when the concentration of organic waste gas is high, the organic waste gas directly enters the non-contact regenerative thermal oxidizer for pyrolysis and discharge.

[0032] (1) Intake - Heat exchange and combustion pyrolysis: The organic waste gas undergoes the first stage of heat exchange through the first heat exchanger 2, reaching 100-300℃. Then, it undergoes the second stage of heat exchange through the second heat exchanger 3, continuing to heat up. Finally, the organic waste gas after two heating cycles flows into the pyrolysis chamber 4, where it is subjected to high-temperature combustion and decomposition by the natural gas burner 5 to obtain purified gas. At this time, the reaction temperature can reach >900℃, and when the concentration of organic waste gas is sufficient, it can sustain combustion.

[0033] (2) Exhaust gas - waste heat absorption and heat exchange and discharge. The high-temperature purified gas after pyrolysis returns to the second heat exchanger 3 and undergoes the second stage of heat energy exchange with the organic waste gas newly entering the second heat exchanger 3. The purified gas with waste heat then enters the first heat exchanger 2 and undergoes the first stage of heat energy exchange with the organic waste gas newly entering the first heat exchanger 2. Finally, the purified gas is discharged into the atmosphere through the first exhaust pipe 9 and meets the emission standards.

[0034] Alternatively, after the second stage of heat exchange, the purified gas can be directly discharged into the atmosphere through the second outlet pipe 11, meeting emission standards.

[0035] 2. Reference Figure 3 In a specific embodiment of this utility model, when the concentration of organic waste gas is low, it can be used in conjunction with a waste gas concentration device;

[0036] The waste gas concentration device uses a zeolite rotor. The organic waste gas is first concentrated by the zeolite rotor and then enters the non-contact regenerative thermal oxidizer for pyrolysis and discharge.

[0037] (1) The adsorption process of the zeolite rotor: organic waste gas passes through the adsorption treatment zone of the zeolite rotor, and the VOCs in the organic waste gas are adsorbed and removed by the adsorbent. The gas after adsorption and purification is then discharged into the atmosphere after meeting the standards.

[0038] (2) In the desorption stage of the zeolite rotor, the organic waste gas VOCs adsorbed in the concentration rotor are desorbed and concentrated to 5-15 times the amount by hot air treatment in the regeneration zone.

[0039] The concentrated desorbed waste gas is sent to the second heat exchanger 3 for the second stage of heat energy exchange, so that it is heated. Then, the heated desorbed waste gas flows into the pyrolysis chamber 4 and is burned and decomposed at high temperature by the natural gas burner 5 to obtain purified gas. The reaction temperature at this time can reach >900℃. When the concentration of desorbed waste gas is sufficient, it can sustain combustion.

[0040] The high-temperature purified gas after pyrolysis returns to the second heat exchanger 3 and undergoes a second stage of heat exchange with the newly entering desorbed waste gas. The purified gas, still carrying residual heat, then flows back into the first heat exchanger 2 and undergoes a first stage of heat exchange with the newly entering cooling stripping gas. Finally, the purified gas is discharged into the atmosphere through the first outlet pipe 9, meeting emission standards.

[0041] (3) Cooling stage of zeolite rotor: Here, the temperature is reduced by cooling air to restore its adsorption capacity;

[0042] The cooled stripped gas is sent to the first heat exchanger 2 for the first stage of heat exchange, so that the heat exchange reaches >100°C. Then it is discharged through the first outlet pipe 9 and sent back to the zeolite rotor for use as regenerated air, thus achieving energy saving.

[0043] The present invention has been described in detail above. The above description is only a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of this application should still fall within the scope of the present invention.

Claims

1. A non-contact regenerative thermal oxidizer, characterized in that: The device includes an outer casing for a thermal oxidizer, a first heat exchanger, a second heat exchanger, a pyrolysis chamber, and a natural gas burner. The first heat exchanger, the second heat exchanger, the pyrolysis chamber, and the natural gas burner are all installed inside the outer casing of the thermal oxidizer. The first heat exchanger and the second heat exchanger are spaced apart and connected to each other. The pyrolysis chamber is located on top of the second heat exchanger and is connected to it. The natural gas burner is located on one side of the pyrolysis chamber and is connected to it.

2. The non-contact regenerative thermal oxidizer according to claim 1, characterized in that: A first connecting pipe and a second connecting pipe are provided at an interval between the first heat exchanger and the second heat exchanger.

3. The non-contact regenerative thermal oxidizer according to claim 1, characterized in that: The first heat exchanger is provided with a first air inlet pipe and a first air outlet pipe on its side and bottom, respectively.

4. The non-contact regenerative thermal oxidizer according to claim 1, characterized in that: The second heat exchanger is provided with a second air inlet pipe and a second air outlet pipe on its side and bottom, respectively.

5. The non-contact regenerative thermal oxidizer according to claim 1, characterized in that: A pyrolysis inlet pipe and a pyrolysis outlet pipe are provided at intervals between the pyrolysis chamber and the second heat exchanger.

6. The non-contact regenerative thermal oxidizer according to claim 1, characterized in that: The pyrolysis chamber is lined with heat storage packing material on the side closest to the second heat exchanger.

7. The non-contact regenerative thermal oxidizer according to claim 1, characterized in that: The first heat exchanger, the second heat exchanger, and the pyrolysis chamber all use a double-layer shell, with flame-retardant and heat-insulating material filling the space between the layers.

Images