RTO for low-ignition-point waste gas treatment

Abstract

The utility model relates to an RTO (regenerative thermal oxidizer) for low-ignition-point waste gas treatment, a first heat accumulator layer and a second heat accumulator layer are arranged in a heat accumulation chamber of an RTO body, the first heat accumulator layer and the second heat accumulator layer are arranged at intervals in the longitudinal direction, and the second heat accumulator layer is arranged above the first heat accumulator layer; the air inlet end of the bypass air duct is communicated with the heat storage chamber and located above the first heat storage body layer, the bypass air duct is used for penetrating through the heat storage chamber of the RTO body and the hearth, and the bypass air duct at least crosses one second heat storage body layer. According to the RTO for low-ignition-point waste gas treatment, by arranging the bypass air duct, the overtemperature of the heat storage chamber caused by advanced oxidation of low-ignition-point component VOCs waste gas can be avoided, the spontaneous-combustion low-ignition-point component VOCs waste gas is bypassed and directly enters the hearth, self-sustaining combustion of the hearth is maintained, fuel consumption is reduced, energy consumption is reduced, and the energy consumption is reduced; and the exhaust overtemperature of the RTO outlet during exhaust can be effectively avoided, and the system stability is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of waste gas treatment, especially to a RTO for low ignition point waste gas treatment. BACKGROUND

[0002] The full name of RTO in Chinese is "regenerative thermal oxidizer", which is one of the most efficient and most commonly used devices in the current VOCs (Volatile Organic Compounds) treatment field. RTO device has two-bed type, three-bed type, multi-bed type and rotary type, mainly composed of furnace body, inlet and outlet air duct, switching valve (rotary valve), regenerative chamber, hearth and combustion system; high temperature of hearth realizes oxidation purification of VOCs, regenerative chamber has the function of heat recovery and release, the regenerative body of regenerative chamber is porous ceramic structure, waste gas can flow in the regenerative body channel, and heat exchange is carried out with regenerative body ceramic during flow, so the regenerative chamber has the function of heat recovery and release, when low temperature gas flows, the heat stored in the regenerative body is released and transferred to the low temperature gas, and the temperature of the regenerative body decreases while the temperature of the gas increases; when high temperature gas flows, the temperature of the gas is transferred to the regenerative body, and the temperature of the regenerative body increases due to the absorption of heat while the temperature of the gas decreases. Through valve switching, the heat recovery / release function of regenerative chamber is alternated, realizing more than 95% heat recovery efficiency and self-sustaining combustion of hearth.

[0003] When treating ordinary component VOCs waste gas, the above-mentioned traditional RTO device has very ideal operation effect and can save energy consumption. However, when VOCs waste gas contains a large amount of low ignition point components, the low ignition point waste gas enters the regenerative chamber, and the temperature of the waste gas has been preheated to the ignition point of the waste gas at the inlet section of the regenerative chamber, resulting in that the low ignition point components are oxidized and exothermic in the regenerative chamber in advance, and the temperature of the waste gas after oxidation is higher than the temperature of the regenerative body, so the regenerative body which should release heat is forced to absorb heat, resulting in that the temperature of the regenerative chamber is too high; at this time, the heat released by the oxidation of VOCs components is absorbed by the inlet regenerative body, and the heat released by the oxidation of VOCs components cannot enter the hearth, resulting in that the temperature of the hearth is insufficient, and when the regenerative chamber is switched to the exhaust regenerative chamber, the heat absorbed by the regenerative body is released in large amount, resulting in that the temperature of the RTO exhaust outlet is too high, that is, the phenomenon of too high temperature of the regenerative chamber and RTO exhaust and too low temperature of the hearth occurs, so it is necessary to continuously supplement fuel to increase and maintain the temperature of the hearth. In this way, the conventional RTO has three disadvantages of overheating of regenerative chamber, overheating of RTO exhaust and large fuel consumption and high energy consumption when treating low ignition point waste gas.

[0004] The patent with the patent number 202010634555.7 discloses a heat storage chamber thermal oxidation device and process for treating electroplating sludge sintering waste gas. The patent specifically discloses that the height of the regular heat storage body in the heat storage chamber thermal oxidation furnace is adjusted to be in the range of 900-1200 mm, so that low ignition point substances can quickly pass through the heat storage bed layer and avoid burning in the regular heat storage body. However, due to the different components of VOCs waste gas in different projects, the height of the heat storage body needs to be redesigned according to the components of different VOCs waste gas, which will cause a large amount of work for project design and is not conducive to large-scale application and production.

[0005] The patent with the patent number 202020130210.3 discloses a waste gas treatment system of RTO. The patent specifically discloses that one end of the heat storage chamber 4 is provided with a refrigerant pump 3 connected therewith. That is, the patent realizes the cooling of the heat storage layer by the cooling of the refrigerant, and the transportation of the refrigerant also causes a large energy waste problem. Utility model content

[0006] Therefore, it is necessary to provide an RTO for low ignition point waste gas treatment to solve the problems of over-temperature of the heat storage chamber, over-temperature of the RTO exhaust gas and large fuel consumption and high energy consumption when a large amount of low ignition point components are contained in the VOCs waste gas.

[0007] To achieve the above-mentioned purpose, the inventors provide an RTO for low ignition point waste gas treatment, which comprises:

[0008] an RTO body, a first heat storage body layer and a second heat storage body layer are arranged in the heat storage chamber of the RTO body, the first heat storage body layer and the second heat storage body layer are arranged in the longitudinal direction, and the second heat storage body layer is arranged above the first heat storage body layer;

[0009] a bypass air duct, the inlet end of the bypass air duct is communicated with the heat storage chamber and located above the first heat storage body layer, the outlet end of the bypass air duct is communicated with the hearth of the RTO body, the bypass air duct is used to pass through the heat storage chamber and the hearth of the RTO body, and the bypass air duct at least spans one second heat storage body layer, and a valve is arranged on the bypass air duct.

[0010] Further, the second heat storage body layer is multi-layered, and the multi-layered second heat storage body layers are arranged in intervals. The inlet end of the bypass air duct is communicated between the first heat storage body layer and the second heat storage body layer, or the inlet end of the bypass air duct is communicated between two adjacent second heat storage body layers.

[0011] Further, each heat storage chamber of the RTO body is correspondingly provided with a bypass air duct.

[0012] Further, the valve is arranged at the inlet end of the bypass air duct.

[0013] Further, a plurality of heat storage bracket is arranged in the RTO body, the heat storage bracket is connected with the inner wall of the RTO body, the first heat storage layer and the second heat storage layer are placed on the heat storage bracket correspondingly.

[0014] Further, the bypass air duct is a " ] " structure.

[0015] Further, the valve is an electromagnetic valve.

[0016] The inventor also provides a method for treating low ignition point waste gas using the RTO for low ignition point waste gas treatment of any of the above solutions, comprising the following steps:

[0017] Passing the waste gas into the inlet bed of the RTO;

[0018] Opening the bypass air duct valve, so that the waste gas passes through the first heat storage layer and enters the furnace from the bypass air duct, or passes through the first heat storage layer and a plurality of second heat storage layers and enters the furnace from the bypass air duct.

[0019] Further, the bypass air duct is provided with a plurality of gas inlet ends, one of which is connected between the first heat storage layer and the second heat storage layer, and the rest are connected between adjacent two second heat storage layers.

[0020] Different from the prior art, the above technical solution has the following advantages: when the RTO for low ignition point waste gas treatment is used, a certain heat storage chamber of the RTO body is used for gas inlet, the valve of the bypass air duct corresponding to the heat storage chamber is opened, so that the VOCs waste gas passes through the first heat storage layer and directly enters the furnace from the bypass air duct. The bypass air duct will directly send the high-temperature VOCs gas that has already self-ignited into the furnace, avoiding heat accumulation in the second heat storage layer, so as to avoid the situation that the heat storage chamber is over-temperature and the furnace temperature is insufficient and needs to be supplemented with fuel. The RTO for low ignition point waste gas treatment can not only avoid the over-temperature of the heat storage chamber caused by the early oxidation of low ignition point component VOCs waste gas, but also directly enter the furnace by bypassing the low ignition point component VOCs waste gas that has self-ignited, maintain self-sustaining combustion of the furnace, reduce fuel consumption, reduce energy consumption, effectively avoid over-temperature of the RTO outlet exhaust gas during exhaust, and improve system stability. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a whole structure schematic diagram of the RTO for low ignition point waste gas treatment of the embodiment;

[0022] Figure 2 It is a cross-sectional view of the RTO for low ignition point waste gas treatment of the embodiment;

[0023] Figure 3Another sectional view of the RTO for low-burning-point waste gas treatment according to the present embodiment;

[0024] Figure 4 A flow schematic of the airflow in the RTO for low-burning-point waste gas treatment according to the present embodiment;

[0025] Figure 5 A schematic view of the RTO for low-burning-point waste gas treatment according to the present embodiment, in which two second regenerator layers are provided.

[0026] BRIEF DESCRIPTION OF REFERENCE NUMERALS

[0027] 1. RTO body

[0028] 11. Regenerator chamber

[0029] 111. First regenerator layer

[0030] 112. Second regenerator layer

[0031] 12. Regenerator bracket

[0032] 13. Furnace

[0033] 2. Bypass air duct

[0034] 21. Intake end of bypass air duct

[0035] 22. Exhaust end of bypass air duct

[0036] 23. Valve DETAILED DESCRIPTION

[0037] In order to describe the possible application scenarios, technical principles, specific schemes that can be implemented, and the purposes and effects that can be achieved of the present application in detail, the following will be described in detail in combination with the specific embodiments listed and with the aid of the accompanying drawings. The embodiments described in the present document are only used to more clearly illustrate the technical schemes of the present application, and therefore only serve as examples, and cannot be used to limit the protection scope of the present application.

[0038] In the present document, the term "embodiment" means that the specific features, structures or characteristics described in combination with the embodiment can be included in at least one embodiment of the present application. The term "embodiment" appearing at various positions in the specification does not necessarily refer to the same embodiment, and does not particularly limit the independence or association between other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, each technical feature mentioned in each embodiment can be combined in any way to form a corresponding implementable technical scheme.

[0039] Unless otherwise defined, the meanings of technical terms used in the present application are the same as those commonly understood by one skilled in the art to which the present application belongs; the use of related terms herein is only for the purpose of describing specific embodiments of the present application, and is not intended to limit the present application.

[0040] In the description of the present application, the phrase "and / or" is a description of a logical relationship between objects, which means that there can be three relationships, for example, A and / or B, which means that there are three cases: A exists, B exists, and A and B exist at the same time. In addition, the character " / " herein generally represents that the associated objects before and after are a "or" logical relationship.

[0041] In the present application, the phrases such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual quantity, primary and secondary, or order relationship between the entities or operations.

[0042] In the present application, without more limitation, the "includes", "contains", "has" or other similar expressions used in the sentence are intended to cover non-exclusive inclusion, and these expressions do not exclude the presence of other elements in the process, method or product including the described elements, so that the process, method or product including a series of elements can not only include those limited elements, but also include other elements not explicitly listed, or also include the elements inherent to such process, method or product.

[0043] As the same as the understanding in the "Guidelines for Examination", in the present application, the expressions such as "greater than", "less than", "exceed" are understood as not including the number; the expressions such as "above", "below", "within" are understood as including the number. In addition, in the description of the embodiments of the present application, the meaning of "multiple" is more than two (including two), and similar expressions related to "multiple" are also understood in this way, for example, "multiple groups", "multiple times" and the like, unless otherwise explicitly limited.

[0044] In the description of the embodiments of the present application, the spatial-related expressions used, such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "perpendicular", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or the drawings, and are only for the convenience of describing the specific embodiments of the present application or for the reader to understand, and are not intended to indicate or imply that the indicated device or component must have a specific position, a specific orientation, or be constructed or operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0045] Unless otherwise defined, or limited by context, the terms used herein such as "install", "connect", "connection", "fix", "set", and the like, are to be construed to be broadest in scope and meant not to limit the items connected by such terms. For example, the "connection" can be fixed connection, or detachable connection, or integrated setting; it can be mechanical connection, or electrical connection, or communication connection; it can be direct connection, or indirect connection via an intermediate medium; it can be internal connection between two elements, or interaction relationship between two elements. The specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances by those skilled in the art.

[0046] Please refer to Figures 1 to 5 The RTO for low ignition point waste gas treatment comprises:

[0047] The RTO body 1 is provided with a first heat storage layer 111 and a second heat storage layer 112 in the heat storage chamber 11, the first heat storage layer 111 and the second heat storage layer 112 are arranged along the longitudinal direction, and the second heat storage layer 112 is arranged above the first heat storage layer 111.

[0048] The bypass air duct 2 is communicated with the heat storage chamber 11 at the air inlet end 21 above the first heat storage layer 111, and the air outlet end 22 is communicated with the furnace chamber 13 of the RTO body 1. The bypass air duct 2 is used to pass through the heat storage chamber 11 and the furnace chamber 13 of the RTO body 1, and at least one second heat storage layer 112 is crossed, and the valve 23 is arranged on the bypass air duct 2.

[0049] Taking a three-bed RTO device as an example, it comprises three parallel arranged heat storage chambers 11 and a furnace chamber 13 communicated above the three heat storage chambers 11. Since each heat storage chamber 11 is used for air inlet, air outlet and cleaning in turn, each heat storage chamber 11 is provided with a first heat storage layer 111 and a second heat storage layer 112, and the bypass air duct is started when the heat storage chamber 11 is air inlet. The first heat storage layer 111 and the second heat storage layer 112 cover the cross section of the heat storage chamber 11, so that all the VOCs waste gas entering the heat storage chamber 11 will pass through the first heat storage layer 111 or the first heat storage layer 111 + the second heat storage layer 112 to reach the furnace chamber 13 of the RTO body 1.

[0050] Generally, the heat storage chamber 11 is a cuboid chamber structure, the first heat storage layer 111 and the second heat storage layer 112 are arranged along the longitudinal direction of the heat storage chamber 11, and the first heat storage layer 111 and the second heat storage layer 112 are both block structures adapted to the inner wall of the heat storage chamber 11. Specifically, the first heat storage layer 111 and the second heat storage layer 112 are both cuboid porous ceramic block structures. The first heat storage layer 111 and the second heat storage layer 112 can be designed as block structures with the same thickness to facilitate the standardization of the heat storage layer. Of course, the first heat storage layer 111 and the second heat storage layer 112 can also be designed with different thicknesses according to the specific components of the VOCs exhaust gas. The heat storage layer can also be a unit thickness value, and different numbers of unit thickness value heat storage layers can be stacked in the first heat storage layer 111 and the second heat storage layer 112, or the same number of unit thickness value heat storage layers can be stacked in the first heat storage layer 111 and the second heat storage layer 112.

[0051] The internal shape of each position cross section of the bypass air duct 2 is square, and of course can also be circular, triangular, elliptical or other shapes. Preferably, the shape and size of the cross section of the bypass air duct 2 are the same at each position, and of course can also be different. The side wall of the bypass air duct 2 is provided with a heat preservation layer, like the bore wall of the RTO body 1, for heat preservation of the gas inside.

[0052] The bypass air duct 2 can be provided between the first heat storage layer 111 and the second heat storage layer 112, or directly above the second heat storage layer 112. Since the second heat storage layer 112 is arranged above the first heat storage layer 111, when the bypass air duct 2 is arranged above the second heat storage layer 112, it is also arranged above the first heat storage layer 111.

[0053] The opening and closing of the bypass air duct 2 can be controlled by operating the valve 23. When the heat storage chamber 11 is inhaling, the valve 23 needs to be opened, so that the exhaust gas does not pass through all the first heat storage layer 111 and the second heat storage layer 112 and directly enters the furnace 13. During the exhaust process and the blow cleaning process, the valve 23 is closed, so that the exhaust gas passes through all the first heat storage layer 111 and the second heat storage layer 112.

[0054] In addition, in order to facilitate the connection of the bypass air duct 2 with the RTO body 1, the cross section of the bypass air duct 2 can be smaller than the interval cross section between the first heat storage layer 111 and the second heat storage layer 112.

[0055] The RTO for low ignition point waste gas treatment uses a certain heat storage chamber 11 of the RTO body 1 for air inlet, opens the valve 23 of the heat storage chamber 11 corresponding to the bypass air duct 2, so that the VOCs waste gas directly enters the furnace 13 from the bypass air duct 2 after passing through the first heat storage layer 111, the bypass air duct 2 directly sends the high-temperature VOCs gas that has self-ignited into the furnace 13, avoids heat accumulation in the second heat storage layer 112, and avoids the situation that the heat storage chamber 11 is overheated and the furnace 13 needs to be supplemented with fuel due to insufficient temperature. The RTO for low ignition point waste gas treatment can not only avoid the overheating of the heat storage chamber 11 caused by the early oxidation of low ignition point component VOCs waste gas, but also directly bypasses the low ignition point component VOCs waste gas that has self-ignited into the furnace 13, maintains self-sustaining combustion of the furnace 13, reduces fuel consumption, reduces energy consumption, effectively avoids the overheating of the RTO outlet exhaust gas during exhaust, and improves system stability.

[0056] The second heat storage layer 112 is a plurality of layers, and the plurality of second heat storage layers 112 are arranged at intervals. The air inlet end 21 of the bypass air duct is connected between the first heat storage layer 111 and the second heat storage layer 112, or the air inlet end 21 of the bypass air duct is connected between two adjacent second heat storage layers 112. The plurality of second heat storage layers 112 are also arranged at intervals along the longitudinal direction of the heat storage chamber 11. To facilitate the connection between the air inlet end 21 of the bypass air duct and the RTO body 1, the cross section of the air inlet end 21 of the bypass air duct can be smaller than the interval cross section between the first heat storage layer 111 and the second heat storage layer 112, and the cross section of the air inlet end 21 of the bypass air duct can be smaller than the interval cross section between two adjacent second heat storage layers 112. When the plurality of second heat storage layers 112 are arranged, the bypass air duct 2 will cross at least one second heat storage layer 112, so that the waste gas is directly sent from the heat storage chamber 11 to the furnace 13, and heat accumulation in one or more second heat storage layers 112 is avoided to prevent the situation that the heat storage chamber 11 is overheated and the furnace 13 needs to be supplemented with fuel due to insufficient temperature. The bypass air duct 2 will cross the second heat storage layer 112 closest to the furnace 13, or the bypass air duct 2 will cross a plurality of adjacent second heat storage layers 112 close to the furnace 13.

[0057] The valve 23 is arranged at the air inlet end 21 of the bypass air duct, which can avoid waste gas accumulation in the bypass air duct 2 as much as possible. Of course, the valve 23 can also be arranged in the middle of the bypass air duct 2, or the valve 23 can be arranged at the air outlet end 22 of the bypass air duct.

[0058] The RTO body 1 is provided with a plurality of heat storage bracket 12, the heat storage bracket 12 is connected with the inner wall of RTO body 1, the first heat storage layer 111 and the second heat storage layer 112 are placed on the heat storage bracket 12 correspondingly. The heat storage bracket 12 and the inner wall of RTO body 1 can be fixedly connected or detachably connected, the heat storage bracket 12 is the supporting structure of the heat storage layer, the heat storage chamber 11 is separated by arranging the heat storage bracket 12, and the heat storage bracket 12 can support the first heat storage layer 111 and the second heat storage layer 112.

[0059] The bypass air duct 2 is a "]" shaped structure, and the middle part of the bypass air duct 2 is arranged in the furnace wall of the RTO body 1. The environment in the bypass air duct 2 and the environment in the RTO body 1 are independent of each other.

[0060] The valve 23 is an electromagnetic valve, which can realize remote control of the opening and closing of the valve 23.

[0061] The inventor also provides a method for treating low-burning-point waste gas, which uses the RTO for low-burning-point waste gas treatment in any of the above-mentioned schemes, and comprises the following steps:

[0062] The waste gas is introduced into the inlet bed of the RTO;

[0063] The valve 23 of the bypass air duct 2 is opened, so that the waste gas passes through the first heat storage layer 111 and then enters the furnace 13 from the bypass air duct 2, or the waste gas passes through the first heat storage layer 111 and a plurality of second heat storage layers 112 and then enters the furnace 13 from the bypass air duct 2.

[0064] In some embodiments, the bypass air duct 2 is provided with a plurality of gas inlet ends, one of which is connected between the first heat storage layer 111 and the second heat storage layer 112, and the remaining gas inlet ends are connected between adjacent two second heat storage layers 112. Each gas inlet end is provided with a valve 23. The gas inlet end is arranged between the first heat storage layer 111 and the second heat storage layer 112, and the gas inlet end is arranged between adjacent two second heat storage layers 112. According to the composition of the treated VOCs waste gas, the valve 23 corresponding to the opened gas inlet end can be selected, so as to avoid heat accumulation in one or more second heat storage layers 112, so as to avoid the case that the temperature of the heat storage chamber 11 is too high and the temperature of the furnace 13 is insufficient and needs to be supplemented with fuel.

[0065] The inventor also provides a method for treating low-burning-point waste gas, which uses the RTO for low-burning-point waste gas treatment in this embodiment, and comprises the following steps:

[0066] The waste gas is introduced into the inlet bed of the RTO;

[0067] The temperature of the first heat storage layer 111 and the second heat storage layer 112 is monitored, if the temperature of the first heat storage layer 111 is higher than a preset temperature, the valve 23 of the bypass air duct 2 above the first heat storage layer 111 is opened, if the temperature of a certain second heat storage layer 112 is higher than a preset temperature, the valve 23 of the bypass air duct 2 above the second heat storage layer 112 is opened.

[0068] Finally, it should be noted that although the above embodiments have been described in the specification and drawings of the present application, the patent protection scope of the present application should not be limited. Any technical solution obtained by replacing or modifying the equivalent structure or equivalent process based on the essential concept of the present application, using the content described in the specification and drawings of the present application, and directly or indirectly implementing the technical solutions of the above embodiments in other related technical fields, etc., are all included in the patent protection scope of the present application.

Claims

1. An RTO for low flashpoint waste gas treatment, characterized by, The application relates to a regenerative thermal oxidizer (RTO) with a bypass air duct. The RTO body is provided with a first heat storage layer and a second heat storage layer in the heat storage chamber, the first heat storage layer and the second heat storage layer are arranged in a longitudinal direction, and the second heat storage layer is arranged above the first heat storage layer. The bypass air duct is communicated with the heat storage chamber and is located above the first heat storage layer, the outlet end of the bypass air duct is communicated with the furnace of the RTO body, the bypass air duct is used for penetrating the heat storage chamber and the furnace of the RTO body, and the bypass air duct at least spans one second heat storage layer, and a valve is arranged on the bypass air duct.

2. The RTO for low burn point waste gas treatment according to claim 1, characterized in that: The second heat storage layer is a multi-layer structure, the multi-layer second heat storage layers are arranged in a spaced mode, the inlet end of the bypass air duct is communicated between the first heat storage layer and the second heat storage layer, or the inlet end of the bypass air duct is communicated between two adjacent second heat storage layers.

3. The RTO for low burn point waste gas treatment according to claim 1, characterized in that: Each heat storage chamber of the RTO body is correspondingly provided with a bypass air duct.

4. The RTO for low burn point waste gas treatment according to claim 1, characterized in that: The valve is arranged at the inlet end of the bypass air duct.

5. The RTO for low burn point waste gas treatment according to claim 1, characterized in that: The RTO body is provided with a plurality of heat storage brackets, the heat storage brackets are connected with the inner wall of the RTO body, and the first heat storage layer and the second heat storage layer are correspondingly arranged on the heat storage brackets.

6. The RTO for low burn point waste gas treatment according to claim 1, characterized in that: The bypass air duct is a "T" shaped structure.

7. The RTO for low burn point waste gas treatment according to claim 1, characterized in that: The valve is an electromagnetic valve.

8. The RTO for low burn point waste gas treatment according to claim 1 or 2, characterized in that: The bypass air duct is provided with a plurality of inlet ends, one of the inlet ends is communicated between the first heat storage layer and the second heat storage layer, and the other inlet ends are communicated between two adjacent second heat storage layers.

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