Harmful component heating purification device

Abstract

To solve the problem that conventional harmful gas treatment device consumes a lot of energy and there is room for improvement in a purification rate.SOLUTION: Each combustion tower is composed of a heat storage unit and a heating combustion chamber from a bottom, where with the heating combustion chambers of the respective combustion towers separated by a partition wall, heating combustion units of the respective combustion towers communicate with each other via a communication part at an upper part of the heating combustion chambers. Further, by maintaining the relation shown in Equation (1) between a capacity (Av) of the heating combustion chamber and a rated flow rate (RBg) for introducing harmful gas, a harmful component heating purification device is provided that can solve the above-mentioned problem.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a harmful component heating and purification device that heats and oxidizes harmful components such as CO (carbon monoxide), HC (hydrocarbon: gas containing organic odor components), bacteria, and mites in various gases (any gas containing any of these components will be referred to as "harmful gas" hereinafter). [Background technology]

[0002] Harmful gases emitted from paint factories, chemical factories, etc. are usually rendered harmless by high-temperature combustion or oxidation using a catalyst. Direct combustion deodorizers and catalytic deodorizers are used for this purpose. Thermal storage deodorizers, which increase thermal efficiency by supplying and exhausting gases to a heated combustion chamber via a thermal storage body, are also known.

[0003] A conventional regenerative combustion deodorization device has a communication section with a heating device located above, a bottom surface with an opening formed below, and three or more chambers separated by walls except for the communication section, and a heat storage layer is provided in each chamber between the opening side and the communication section. Harmful gases are heated and combusted by the heating device in the communication section, where they are decomposed and become purified gas.

[0004] The opening has: a communication port communicating with an inflow passage for introducing harmful gas into the chamber; a communication port communicating with an outlet flow path for discharging purified gas from the chamber; a communication port communicating with a purge flow path through which a purge gas is introduced into the chamber; The opening and closing of each communication port is controlled by an electromagnetic on-off valve or the like. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-236793 Summary of the Invention [Problem to be solved by the invention]

[0006] In the three-tower regenerative combustion type exhaust gas purification system described in Patent Document 1, a harmful component thermal purification device has a first tower, a second tower, and a third tower arranged in parallel, each with a heat storage body inside. At the bottom of each of the first, second, and third towers, there is a communication port for introducing harmful gas, a communication port for discharging purified gas, and a communication port for introducing purge gas.

[0007] Above each tower is a connected sealed space, inside which a heating device and a temperature sensor for temperature control are installed.

[0008] Each tower opens and closes its communication ports to repeat the cycle of introducing hazardous gas, introducing purge gas, discharging purified gas, and then introducing hazardous gas again.The three towers are also controlled so that their processes do not overlap.

[0009] The harmful gas introduced into the tower where the harmful gas is introduced is heated by passing through a heat storage medium, and the harmful components in the harmful gas are burned and purified in the heated sealed space above (hereinafter referred to as "combustion purification"). At this time, the sealed space above is controlled to a temperature of approximately 800°C or higher.

[0010] The purified, high-temperature gas is discharged from another tower that serves as the purified gas discharge step. When this purified gas is discharged, heat exchange occurs between the purified gas and the heat storage body of that tower, and heat accumulates in the heat storage body.

[0011] The heat storage body stores heat as the purified gas passes through, but its temperature does not rise above the temperature at which the purified gas entered. The temperature of the harmful gas entering the sealed space from the tower that serves as the introduction process for the harmful gas is also raised by the heat storage body of the tower. However, it is supplied to the sealed space at a lower temperature than the temperature inside the sealed space. To purify the harmful gas, the harmful gas must mix with the gas in the sealed space and reach a temperature at which the harmful components can be burned and purified. Therefore, the temperature of the entire sealed space must be set higher than the minimum temperature at which combustion purification is possible. This is undesirable from the standpoint of energy efficiency. This was the first challenge.

[0012] In the gas flow switching cycle, the order is the purified gas discharge process, followed by the harmful gas introduction process. The gas flow switches in this order in each tower. In the tower where the purified gas discharge process is in progress, the purified gas flows downward from the top of the heat storage body, and at the top of the heat storage body, a downward flow is created in which the gas in the sealed space flows toward the opening at the top of the heat storage body.

[0013] In this situation, the gas flow switching cycle instantly reverses the gas flow. Therefore, the downward flow of purified gas acts as a resistance to the upward flow of harmful gas from the upper opening of the regenerator, which is trying to enter the sealed space. At this time, there is another tower next to this tower that is in the process of discharging purified gas, so some of the harmful gas entering the sealed space is discharged without being given enough time to be heated inside the sealed space. In other words, the harmful gas purification rate deteriorates immediately after the mode switch. This was the second issue. [Means for solving the problem]

[0014] The present invention has been conceived to solve the first and second problems. More specifically, the harmful component thermal purification device according to the present invention comprises: At least three or more regenerative heating and combustion towers each having an upper opening and a lower opening; a communication passage connecting the upper openings of the regenerative thermal combustion towers to each other; Each of the regenerative heating combustion towers has: The lower opening of the regenerative heating combustion tower a harmful gas inlet communicating with a harmful gas inlet passage for introducing harmful gas into the regenerative thermal combustion tower; a purified gas outlet communicating with an exhaust flow path for exhausting purified gas from the regenerative thermal combustion tower; Three openings of a purge gas inlet communicating with a purge gas introduction passage that introduces a purge gas into the regenerative heating combustion tower; a flow path opening / closing valve for separately opening and closing the harmful gas introduction flow path, the exhaust flow path, and the purge gas introduction flow path is provided; Between the lower opening and the upper opening of the regenerative heating combustion tower, a heat storage section (comprising a heat storage body); A heating combustion chamber equipped with a heat source is provided above the heat storage section, The thermal combustion chamber is characterized in that it is configured so that the volume (Av) of the thermal combustion chamber satisfies the following equation (1) relative to the constant flow rate (RBg) of harmful gas passing through the thermal storage thermal combustion tower.

[0015]

number

[0016] In the harmful component thermal purification device according to the present invention, the space (heating combustion chamber) where harmful gas components are burned and purified is separated by a partition above the heat storage body of each tower to prevent mixing with gas above other towers or in the connecting passage. Furthermore, since the heating of this space (heating combustion chamber) is controlled independently for each tower, the combustion purification space (heating combustion chamber) can be controlled to a uniform and efficient optimum temperature, thereby solving the first problem.

[0017] Furthermore, harmful gas components first pass through the thermal combustion chamber of the tower in the exhaust gas introduction process, then pass through the connecting passage to reliably pass through the thermal combustion chamber of the tower in the purified gas discharge process. This is because harmful gas cannot enter the tower in the purified gas discharge process unless it passes through the thermal combustion chamber from the connecting passage. Therefore, harmful gas can reliably remain in the thermal combustion chamber for the time required to heat and burn the harmful components, thereby solving the second problem. [Brief explanation of the drawings]

[0018] [Figure 1] 1A and 1B are cross-sectional views of a harmful component thermal purification device according to the present invention, in which (a) is a cross-sectional view from the front and (b) is a cross-sectional view from the side. [Figure 2] FIG. 2 is a diagram showing the gas flow in one mode in the harmful component thermal purification device. [Figure 3] FIG. 4 is a flowchart showing a processing flow of a control unit. [Figure 4] 1 is a graph showing the volumetric air flow ratio (Bg / Av) ( / s) and the harmful gas purification rate (%) in a harmful component thermal purification device. [Figure 5] 1 is a graph showing the volumetric airflow ratio (Bg / Av) ( / s) and unit airflow power consumption (Wh / m3) in a harmful component thermal purification device. [Figure 6] 1A and 1B are cross-sectional views showing the configuration of a conventional device for purifying harmful components by heating (comparison device), where (a) is a cross-sectional view from the front and (b) is a cross-sectional view from the side. [Figure 7] FIG. 1 is a diagram showing the gas flow in one mode in a conventional harmful component thermal purification device. [Figure 8] 1 is a graph comparing the temperature (° C.) of the heating fuel chamber and the purification rate (%) between the example device and the comparative example device. [Figure 9] 10 is a graph showing the concentration (ppm) of harmful components in purified gas before and after mode transition in the device of the embodiment. [Figure 10] 10 is a graph showing the concentration (ppm) of harmful components in purified gas before and after mode transition in a comparative example device. [Figure 11]10A and 10B are diagrams showing gas flows before and after a mode transition in the comparative example device, where (a) shows the flow before the mode transition and (b) shows the flow after the mode transition. DETAILED DESCRIPTION OF THE INVENTION

[0019] The harmful component thermal purification device according to the present invention will be described below with reference to the drawings and examples. Note that the following description illustrates one embodiment of the present invention and one example, and the present invention is not limited to the following description. The following description can be modified within the scope of the present invention. Furthermore, in the following description, the flow rate may be a normal flow rate (a flow rate converted into a volume at 0°C and 0 MPaG).

[0020] Figure 1 shows the configuration of a harmful component thermal purification device (1) according to the present invention. Figure 1(a) is a cross-sectional view of the harmful component thermal purification device (1) from the front. Figure 1(b) is a cross-sectional view of a regenerative thermal combustion tower y from the side.

[0021] The harmful component thermal purification device (1) has at least three regenerative thermal combustion towers. Figure 1 shows an example in which it is composed of three regenerative thermal combustion towers (x, y, z). The lower part of each regenerative thermal combustion tower has a lower opening (17) consisting of openings (referred to as harmful gas inlet 17a, purge gas inlet 17b, and purified gas outlet 17c) that communicate with a harmful gas inlet flow path (30a), a purge gas inlet flow path (30b), and a purified gas outlet flow path (30c) (see Figure 1(b)).

[0022] The flow paths are provided with flow path opening / closing valves (16: designated by the symbols 16a, 16b, and 16c, respectively), and each regenerative thermal combustion tower is selectively connected to one of the flow paths. Furthermore, each regenerative thermal combustion tower is always connected to a different flow path, and is not constantly connected to the same flow path. In other words, it is not excluded that multiple regenerative thermal combustion towers may be connected to the same flow path at any one time.

[0023] Each regenerative combustion tower has a heat storage body (7) and a combustion chamber (8), and the combustion chamber (8) has a heat source (5) and a temperature sensor (6). The upper portions of the combustion chambers (8) of the regenerative combustion towers are connected by a communication passage (13). The amount of harmful gas introduced (Bg) (L / s) is controlled by a harmful gas introduction fan (9). A harmful component concentration sensor (52) may be provided in the purified gas discharge path (30c). Purge gas is introduced by a purge air introduction fan (10).

[0024] Ceramic honeycomb is commonly used for the heat storage body (7). However, other ceramic structures or metals can also be used as the heat storage body (7) as long as they are heat-resistant and have a structure that allows gas to pass through. A gas burner (radiant tube burner) or an electric heater can be used as the heat source (5).

[0025] The capacity (Av) (L) of the combustion chamber (8) of each regenerative combustion tower is the same and is expressed as w × h × t in FIG. 1. That is, the capacity (Av) of the combustion chamber (8) is determined by the width (w) as viewed from the front (FIG. 1(a)) of the harmful component thermal purification device (1), the height (h) as viewed from the side (FIG. 1(b)). The height (h) refers to the distance from the top of the regenerative body (7) to the connecting passage (13). Therefore, the top of the combustion chamber (8) is in contact with the connecting passage (13), and there is a side wall (32) of the regenerative combustion tower between adjacent combustion chambers. That is, the combustion chambers (8) of each regenerative combustion tower are separated by a partition wall (side wall 32 of the regenerative combustion tower).

[0026] The capacity (Pv) of the communication passages (13) is calculated by the formula wp × hp × tp, where wp is the width, hp is the height, and tp is the thickness when the harmful component thermal purification device (1) is viewed from the front. The capacity (Pv) of the communication passages (13) per combustion chamber (8) is preferably 0.05 to 0.3 times the capacity (Av) of one combustion chamber (8), and more preferably 0.1 to 0.25 times the capacity (Av) of one combustion chamber (8).

[0027] Here, the capacity (Pv) of the communication passage (13) per one combustion chamber (8) is calculated by dividing the capacity (Pv) of the communication passage (13) by the number of combustion chambers (8). For example, if the capacity (Pv) of the communication passage (13) per combustion chamber (8) is defined as a unit communication passage capacity (UPv), the unit communication passage capacity (UPv) can be expressed by equation (4).

[0028]

number

[0029] If the capacity of the communicating passage (13) is too small, it will create resistance to the gas flow, requiring a high-pressure harmful gas introduction fan and a structure that can withstand high pressure for the entire gas flow path. Also, if the capacity of the communicating passage (13) is too large, the surface area of ​​the communicating passage (13) will increase, and the temperature inside the communicating furnace will drop due to heat radiation from the communicating furnace, resulting in an increase in the concentration of harmful components in the purified gas.

[0030] In the harmful component thermal purification device (1) according to the present invention, the amount of harmful gas to be treated (the same as the amount of harmful gas introduced (Bg) by the harmful gas introduction fan (9)) is set within a certain range relative to the capacity (Av) of the thermal combustion chamber (8), thereby achieving a high purification rate and low power consumption, as will be shown in the examples described later.

[0031] This can be said to mean that the capacity (Av) of the heating combustion chamber (8) is set within a certain range relative to the amount (Bg) of harmful gas introduced into the harmful component thermal purification device (1), or it can be said that the amount (Bg) of harmful gas introduced is controlled within a certain range relative to the capacity (Av) of the heating combustion chamber (8).

[0032] In the following description, the "rated flow rate (RBg)" refers to the amount (Bg) of harmful gas introduced into the harmful component thermal purification device (1) at which the device can be effective, i.e., the amount (Bg) of harmful gas introduced into the device during steady operation. For example, the amount (Bg) of harmful gas introduced into the device during steady operation as described in the operating manual or instruction manual of the device for thermal purification of harmful components (1) may be referred to as the "rated flow rate (RBg)."

[0033] In the harmful component thermal purification device (1) according to the present invention, the capacity (Av) of the thermal combustion chamber (8) is set as shown in equation (1) relative to the rated flow rate (RBg).

[0034]

number

[0035] In the harmful component thermal purification device (1) according to the present invention, the rated flow rate (RBg) is set relative to the capacity (Av) of the thermal combustion chamber (8) as shown in equation (2).

[0036]

number

[0037] It has been confirmed that, if the unit communication passage volume (UPv) is within the above range, the formulas (1) and (2) exhibit the effects shown in the examples.

[0038] The harmful component thermal purification device (1) according to the present invention may also include a control unit (50). The control unit (50) replaces the rated flow rate (RBg) in equation (2) with the amount of harmful gas introduced (Bg), and controls the amount of harmful gas introduced (Bg) so that equation (2) always holds. More specifically, the control unit (50) controls the harmful gas introduction fan (9) so that the amount of harmful gas introduced (Bg) satisfies equation (3).

[0039]

number

[0040] The control unit (50) can be configured with a CPU (Central Processor Unit) and a memory. The control unit (50) receives control signals (Ca) for controlling each part of the harmful component thermal purification device (1) and signals (Sa) from each sensor.

[0041] The control signal (Ca) includes instructions for adjusting the heat power of the heat source (5) and for adjusting the operation of the flow path opening / closing valve (16). The signals (Sa) from the sensors include signals from the temperature sensor (6) of the thermal combustion chamber (8) and the temperature sensor of the thermal storage body (7). In particular, the control unit (50) controls the hazardous gas introduction fan (9) with the control signal (Cb) and receives the measurement value of the hazardous component concentration sensor (52) with the signal (Se).

[0042] Figure 2 shows one mode during exhaust gas treatment. Note that the "mode" here indicates which process each regenerative thermal combustion tower in the harmful component thermal purification device (1) is in: the harmful gas introduction process, the purified gas discharge process, or the purge gas introduction process. The change in process of each regenerative thermal combustion tower is called a "mode transition." Also, the control unit (50) is not shown in Figure 2.

[0043] In the mode shown in Figure 2, regenerative combustion tower y is in the harmful gas introduction process, regenerative combustion tower z is in the purified gas discharge process, and regenerative combustion tower x is in the purge gas introduction process. Harmful gas introduced from regenerative combustion tower y passes through the regenerative heat storage (7) (15) to be heated and then passes through the thermal combustion chamber (8) (18-2). It then passes through the connecting passage (13) (18-3) and the thermal combustion chamber (8) of regenerative combustion tower z (18-1), and then passes through the regenerative heat storage (7) of regenerative combustion tower z (12) and is discharged from the harmful component thermal purification device (1). Harmful components in the harmful gas are combusted and purified in the thermal combustion tower y and the thermal combustion chamber (8) of regenerative combustion tower z.

[0044] The order of process changes for each regenerative combustion tower with each mode transition is fixed. Specifically, the regenerative combustion tower into which harmful gas has been introduced next has purge gas introduced, the regenerative combustion tower that was discharging purified gas next has harmful gas introduced, and the regenerative combustion tower that was flowing purge gas next discharges purified gas. In the example of Figure 2, regenerative combustion tower x next moves on to the purified gas discharge process, regenerative combustion tower y moves on to the purge gas introduction process, and regenerative combustion tower z moves on to the harmful gas introduction process.

[0045] 3 shows an example of a processing flow of the control unit 50. When the processing starts (step S100), initial settings are made (step S102). The initial settings include the amount of harmful gas introduced (Bg), the temperature setting of each heat treatment chamber (8), etc. The capacity (Av) of the heat combustion chamber (8) may also be input in the initial settings.

[0046] Next, a termination determination is made (step S104). The termination determination is made based on the end of the harmful gas to be purified, the time (when the end of operation is determined by time, etc.), manual shutdown of the harmful component thermal purification device (1) by an operator, etc. Note that the harmful component thermal purification device (1) may also be stopped due to an abnormality (such as an unexpected high temperature) occurring during operation.

[0047] If the process is to be ended (Y branch of step S104), the process is stopped (step S106). A heat removal process may be performed for each regenerative thermal combustion tower. If the process is to be continued (N branch of step S104), the process is transferred to the next step.

[0048] When the process proceeds to step S108, the temperature of the thermal combustion chamber (8) is increased to a set temperature (step S108). Waiting until the temperature is increased is performed by branching N in step S108. Once the temperature of the thermal combustion chamber (8) has increased to the predetermined temperature (branch Y in step S108), the mode (the process of each regenerative thermal combustion tower) is changed (step S110).

[0049] Next, the harmful components in the treated purified gas are detected by the harmful component concentration sensor (52) to determine whether they are higher than a threshold value (Th) (e.g., 10 ppm) (step S112). If the amount of harmful components is higher than the threshold value Th (Y branch in step S112), the amount of harmful gas introduced (Bg) is reduced by a minute amount ΔBg.

[0050] Since an increase in the concentration of harmful components in the purified gas being exhausted means that unburned harmful gas remains, the purpose is to reduce the amount of unburned gas by reducing the amount of harmful gas introduced (Bg) and extending the time of exposure to high temperatures. After reducing the amount of harmful gas introduced (Bg), the process proceeds to step S120.

[0051] On the other hand, if the concentration of harmful components in the purified gas is equal to or less than the predetermined concentration (Th) (N branch in step S112), it is determined whether the amount of harmful gas introduced (Bg) is stable (step S116). The amount of harmful gas introduced (Bg) may be determined to be stable if the flow rate has not been changed within a predetermined time in the past (step S114).

[0052] If it is not stable (N branch in step S116), the harmful gas introduction amount (Bg) has been changed, so wait until it becomes stable. Specifically, skip to step S120. This is because the harmful components in the purified gas do not change immediately after the flow rate is changed.

[0053] If it is stable (Y branch in step S116), the introduction amount is adjusted (step S118). Here, adjusting the introduction amount means returning the introduction amount (Bg) reduced in step S114 to the flow rate set in the initial setting (step S102). If it is the same as the initial setting of the introduction amount (Bg) of hazardous gas, the introduction amount is not adjusted and step S118 is skipped. By this operation, even if there has been a change in the introduction amount (Bg) of hazardous gas, it can be returned to the initial state of the introduction amount (Bg).

[0054] In addition, to adjust the amount of harmful gas introduced here, an instruction to manually change the amount of harmful gas introduced (Bg) may be given, and the amount of harmful gas introduced (Bg) may be adjusted to respond to the change while maintaining the relationship of equation (3) with the capacity (Av) of the heating combustion chamber (8).

[0055] Next, the combustion temperature is adjusted (step S120). The combustion temperature is adjusted so that the temperature in each heating combustion chamber (8) maintains an initial setting value. Note that, here too, an instruction to artificially change the combustion temperature may be given from the outside, and the adjustment may be made in response to that change.

[0056] Next, it is determined whether the processing time (Ts) has elapsed (step S122). Mode transitions are basically determined by time. This time is designated as Ts. In other words, the mode, which is the process state of each regenerative thermal combustion tower, changes every Ts.

[0057] If the processing time (Ts) has not elapsed (N branch at step S122), the process returns to step S112. If the processing time (Ts) has elapsed (Y branch at step S122), the process returns to the end determination at step S104. If the processing is not to be ended (N branch at step S104), it is determined whether the temperature is rising (step S108). In this case, since the temperature of the harmful component thermal purification device (1) has already risen, this process is essentially skipped. Then, the mode is changed (step S110).

[0058] In this way, the harmful component thermal purification device (1) according to the present invention controls the amount of harmful gas introduced (Bg) so that the amount of harmful gas introduced (Bg) satisfies the relationship of equation (3), thereby making it possible to maintain the concentration of harmful components in the final purified gas at or below a predetermined value. In particular, it is possible to reduce the amount of harmful components leaking during mode transitions.

[0059] Tables 1 and 2 show examples of mode transitions for each tower in the case of three towers and five towers.

[0060] [Table 1]

[0061] [Table 2]

[0062] "Harmful gas" refers to the introduction of harmful gas, "purge" refers to the introduction of purge gas, and "exhaust" refers to the exhaust of post-combustion gas. Tables 1 and 2 show some of the continuous mode transitions of the harmful component thermal purification device (1) in the case of a three-tower configuration and a five-tower configuration, and each mode transition is repeated.

[0063] As shown in Table 2, in the case of a five-tower configuration, the introduction of harmful gases and the exhaust of post-combustion gases are carried out in two consecutive cycles, thereby allowing the operation of the harmful component thermal purification device (1) to continue continuously. [Example]

[0064] Example 1 The harmful component heat purification device (1) of Example 1 (hereinafter referred to as "Example device") uses a ceramic honeycomb with 100 cells / inch as a heat storage body (7). 2 Two stages of 150 x 150 x H300 mm are used. The heating combustion chamber (8) has dimensions of w=158 mm, t=158 mm, and h=600 mm in Fig. 1. Therefore, the capacity (Av) of the heating combustion chamber (8) is 15 L. The upper part of the heating combustion chamber (8) is a connecting passage (13) with a capacity of 3 L.

[0065] Table 3 shows the results of measuring the relationship between heater power consumption (Wh) and purification rate (%) when the amount of harmful gas introduced (Bg) (NL / S) in the example device was varied. The temperature of the heating combustion chamber was fixed at 800°C.

[0066] [Table 3]

[0067] Table 3 shows the results when toluene (approximately 500 ppmc) was used as the toxic gas component, but similar results were obtained with other organic solvent components.

[0068] Figure 4 is a graph of the volumetric airflow ratio (Bg / Av) ( / S) and harmful gas purification rate (%) from Table 3. In Figure 4, the horizontal axis is the volumetric airflow ratio (Bg / Av) ( / S) and the vertical axis is the purification rate (%). When the volumetric airflow ratio (Bg / Av) exceeded 10, the purification rate (%) dropped significantly.

[0069] Figure 5 shows the relationship between the volumetric airflow ratio (Bg / Av) ( / S) and the unit airflow power consumption (Wh / m 3In Figure 5, when the volumetric airflow ratio (Bg / Av) ( / S) is below 0.1, the unit airflow power consumption (Wh / m 3 ) rose sharply. Therefore, from the results of Figures 4 and 5, it was found that the volumetric airflow ratio (Bg / Av) ( / S) can be suitably used in a range between 0.1 and 10, more preferably between 0.5 and 5.0, and most preferably between 0.8 and 3.0. In other words, it is advisable to set this range as the rated flow rate (RBg).

[0070] FIG. 6 shows, as a comparative example, a conventional purification apparatus in which each tower does not have a thermal combustion chamber (8) (hereinafter referred to as the "comparative apparatus"). Each tower has a regenerator (7), but does not have the thermal combustion chamber (8) for each tower of the embodiment apparatus (see FIG. 1). The upper part of the regenerator (7) immediately serves as a communicating thermal purification area (13-2) that also serves as a communicating passage (13). That is, in the comparative apparatus, the thermal combustion chamber (11) serves as a common combustion chamber for each regenerative thermal combustion tower.

[0071] The heat storage body (7) and the lower exhaust gas flow path switching part are almost the same as those in the embodiment device, and the volume of the heating combustion chamber (11) is almost equal to the sum of the volumes of the heating combustion chamber (8) and the connecting passage (13) of each heat storage heating combustion tower in the embodiment device.

[0072] Fig. 7 shows one mode of the comparative example apparatus of Fig. 6. Regenerative combustion tower x is for the purge gas introduction process, regenerative combustion tower y is for the harmful gas introduction process, and regenerative combustion tower z is for the purified gas exhaust process. Harmful gas (15) that has passed through the heat storage body (7) heated in the previous mode in the upper part of regenerative combustion tower y is combusted in the communicating heat purification area (13-2), passes through the heat storage body (7) of regenerative combustion tower z (12), undergoes heat exchange, and is then exhausted as purified gas.

[0073] Table 4 compares the relationship between the temperature of the thermal combustion chamber and the purification rate between the example device and the conventional device. Note that the connected thermal purification area (13-2) of the conventional device will also be referred to as the "thermal combustion chamber" in the following explanation. Figure 8 is a graph of Table 4. Referring to Figure 8, the horizontal axis is the temperature of the thermal combustion chamber (°C) and the vertical axis is the purification rate (%). The purification rate of the conventional device is represented by a circle, and the maximum purification rate of the example device is represented by a triangle. It is clear that with the configuration of the conventional device, the purification rate could not be increased unless the temperature of the thermal combustion chamber was increased. Furthermore, even when the temperature of the thermal combustion chamber of the conventional device was raised to 900°C, it did not reach the purification rate of the example device (99.5%).

[0074] [Table 4]

[0075] Figures 9 and 10 show the timing of mode switching and the change in the concentration of harmful components in the purified gas (the concentration of harmful components discharged unpurified) measured using the example system and the conventional system. The figures show a regenerative combustion tower in the harmful gas introduction process and a regenerative combustion tower in the discharge process. In both figures, the horizontal axis represents elapsed time (s), and the vertical axis represents the concentration of harmful components in the purified gas (ppm).

[0076] In the example device shown in Figure 9, the concentration of harmful components discharged unpurified remained almost unchanged before and after the mode transition. However, in the conventional device shown in Figure 10, the concentration of harmful components in the purified gas increased due to the mode transition, peaked, and then decreased.

[0077] Figure 11 shows the state of the process of mode transition in the comparative example device. Figure 11(a) shows a mode in which regenerative combustion tower x is the harmful gas introduction process and regenerative combustion tower y is the purified gas discharge process. Figure 11(b) shows the next mode after mode transition, in which harmful gas is introduced from regenerative combustion tower y and discharged from regenerative combustion tower z.

[0078] Immediately after switching from the mode in Figure 11(a), while there is a downward gas flow (18) at the top of the regenerative heating combustion tower y, an upward flow of harmful gas occurs from the heat storage body (7) of the regenerative heating combustion tower y, resulting in a gas flow (17-2) that flows into the regenerative heating combustion tower z without being sufficiently retained in the connected heating purification area (13-2), and the harmful components are discharged without being purified, resulting in an emission peak of unpurified harmful components (see Figure 10), which is thought to be the reason for the decrease in the purification rate.

[0079] As described above, the harmful component thermal purification device (1) according to the present invention can achieve a high purification rate and energy saving by providing a thermal combustion chamber (8) for each regenerative thermal combustion tower and by adjusting the amount of harmful gas introduced (Bg) to a predetermined relationship. [Industrial Applicability]

[0080] The harmful component heat purification device according to the present invention can be suitably used to purify harmful gases. [Explanation of symbols]

[0081] 1. Harmful component heating purification device 2. Heat storage heating combustion tower x 3. Heat storage heating combustion tower 4. Heat storage heating combustion tower 5 Heating source 6 Temperature Sensor 7 Heat storage body 8 Heating combustion chamber 9 Harmful gas introduction fan 10 Purge air intake fan 11 Heating combustion chamber 12 Purified gas flow 13 Communication path 13-2 Connected heating and purification area 14 Purge gas flow 15 Flow of harmful gases 16 Flow path opening / closing valve 17 Lower opening 17a Harmful gas inlet 17b Purge gas inlet 17c Purified gas outlet 17-1, 17-2 Gas flow 18 Gas flow over a thermal storage body 19 Gas flow over a thermal storage body 30a Harmful gas introduction passage 30b Purge gas introduction channel 30c Purified gas discharge flow path 32 Side wall 50 control section 52 Harmful substance concentration sensor Av capacity Bg introduction amount RBg Rated flow rate

Claims

1. at least three or more regenerative heating and combustion towers each having an upper opening and a lower opening; a communication passage connecting the upper openings of the regenerative thermal combustion towers to each other; Each of the regenerative heating combustion towers has: The lower opening of the regenerative heating combustion tower a harmful gas inlet communicating with a harmful gas inlet passage for introducing harmful gas into the regenerative thermal combustion tower; a purified gas outlet communicating with an exhaust flow path for exhausting purified gas from the regenerative thermal combustion tower; Three openings of a purge gas inlet communicating with a purge gas introduction passage through which a purge gas is introduced into the regenerative heating combustion tower; a flow path opening / closing valve for separately opening and closing the harmful gas introduction flow path, the exhaust flow path, and the purge gas introduction flow path is provided; Between the lower opening and the upper opening of the regenerative heating combustion tower, a heat storage section (comprising a heat storage body); A heating combustion chamber equipped with a heat source is provided above the heat storage section, A harmful component thermal purification device configured so that the volume (Av) of the thermal combustion chamber satisfies equation (1) relative to the constant flow rate (RBg) of harmful gas passing through the regenerative thermal combustion tower. [Number 100]

2. at least three or more regenerative heating and combustion towers each having an upper opening and a lower opening; a communication passage connecting the upper openings of the regenerative thermal combustion towers to each other; Each of the regenerative heating combustion towers has: The lower opening of the regenerative heating combustion tower a harmful gas inlet communicating with a harmful gas inlet passage for introducing harmful gas into the regenerative thermal combustion tower; a purified gas outlet communicating with an exhaust flow path for exhausting purified gas from the regenerative thermal combustion tower; Three openings of a purge gas inlet communicating with a purge gas introduction passage through which a purge gas is introduced into the regenerative heating combustion tower; a flow path opening / closing valve for separately opening and closing the harmful gas introduction flow path, the exhaust flow path, and the purge gas introduction flow path is provided; Between the lower opening and the upper opening of the regenerative heating combustion tower, a heat storage section (comprising a heat storage body); A heating combustion chamber equipped with a heat source is provided above the heat storage section, The harmful component thermal purification device is set so that the rated flow rate (RBg) of the harmful gas passing through the regenerative thermal combustion tower is set to satisfy the following equation (2) relative to the capacity (Av) of the thermal combustion chamber. [Number 101]

3. at least three or more regenerative heating and combustion towers each having an upper opening and a lower opening; a communication passage connecting the upper openings of the regenerative thermal combustion towers to each other; Each of the regenerative heating combustion towers has: The lower opening of the regenerative heating combustion tower a harmful gas inlet communicating with a harmful gas inlet passage for introducing harmful gas into the regenerative thermal combustion tower; a purified gas outlet communicating with an exhaust flow path for exhausting purified gas from the regenerative thermal combustion tower; Three openings of a purge gas inlet communicating with a purge gas introduction passage through which a purge gas is introduced into the regenerative heating combustion tower; a flow path opening / closing valve for separately opening and closing the harmful gas introduction flow path, the exhaust flow path, and the purge gas introduction flow path is provided; Between the lower opening and the upper opening of the regenerative heating combustion tower, a heat storage section (comprising a heat storage body); A heating combustion chamber equipped with a heat source is provided above the heat storage section, A harmful component thermal purification device having a control unit that controls the flow rate (Bg) of harmful gas passing through the regenerative thermal combustion tower relative to the capacity (Av) of the thermal combustion chamber so that the flow rate satisfies equation (3). [Number 102]

4. Furthermore, a harmful component concentration sensor is provided in an exhaust flow path for discharging the purified gas, 4. The harmful component thermal purification device according to claim 1, wherein a maximum difference in concentration of harmful components in the discharge flow path before and after switching of the flow path opening / closing valve is 10 ppm or less.

5. 4. The harmful component thermal purification device according to claim 1, wherein a unit communication passage capacity, which is the capacity of the communication passage per one heating combustion chamber, is 0.05 to 0.3 times the capacity of the communication passage.

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