KR100598553B1 - Regenerative thermal oxidizer with high thermal efficiency - Google Patents

Abstract

The present invention relates to a combustion plant that burns and removes harmful process gases or wastes generated in an industrial field, and more particularly, to a regenerative combustion plant having a high thermal efficiency by having a heat storage layer that exchanges heat with a combustion gas. The regenerative combustion facility of the present invention supplies cooling gas to the regenerative bed to forcibly cool a part thereof. Accordingly, it is possible to increase the thermal efficiency of the combustion plant by reducing the temperature of the process gas discharged through the heat storage bed.

Regenerative Combustion Facility, Regenerative Bed, Cooling Unit, Heat Loss

Description

High heat efficiency regenerative combustion plant {REGENERATIVE THERMAL OXIDIZER WITH HIGH THERMAL EFFICIENCY}

1 is a block diagram conceptually showing a configuration of a conventional regenerative combustion facility.

2 is a graph conceptually illustrating a temperature profile of combustion gas passing through a regenerative bed of a conventional regenerative combustion installation.

3 is a block diagram conceptually illustrating a configuration of a regenerative combustion facility according to an embodiment of the present invention.

4 is a schematic view for explaining the operation of the heat storage combustion equipment of the present invention.

<Short description of the symbols in the drawings>

100: distribution mechanism 200: heat storage bed

210: separator 300: combustion chamber

310: burner 400: peripherals

The present invention relates to a combustion plant that burns and removes harmful process gases or wastes generated in an industrial site, and more particularly, to a regenerative combustion plant having a high thermal efficiency having a heat storage layer for heat exchange with a combustion gas.

Combustion equipment is a device for oxidizing and releasing hazardous gases or industrial wastes, including volatile organic compounds and unburned gases, generated as process gases in industrial facilities such as waste incinerators, carbonization furnaces or drying furnaces. It is well known that the heat storage type combustion equipment that preheats the feed gas with the high thermal energy of the discharged gas after combustion in these combustion equipments is advantageous in terms of energy saving and toxic gas removal efficiency.

Regenerative combustion equipment can be divided into two bed type, three bed type, rotary rotor type, etc. according to the arrangement and operation method of the heat storage layer according to the structure.

1 is a block diagram schematically showing the configuration of a regenerative combustion facility having a rotary rotor type distribution mechanism in a conventional regenerative combustion facility. As shown, conventional regenerative combustion equipment consists of a rotary distribution mechanism 100, such as a rotary rotor, a regenerative bed 200 and a combustion chamber 300. Referring to Figure 1 describes the operation of the conventional regenerative combustion equipment as follows.

Toxic gas such as VOC gas introduced into the inlet IN of the rotary distribution device 100 is transferred to the preheating part (Part I) of the heat storage bed 200 which communicates with the inlet through the distribution device 100. Inflow. The inlet IN and the outlet OUT of the distribution mechanism 100 each have a communication path corresponding to one-to-one correspondence with the preheating part Part I and the heat storage part Part II of the heat storage bed 200. Each communication path is separated so that gas inflow from the inlet of the distribution mechanism 100 to the heat accumulator PART II does not occur.

The VOC gas flows into the combustion chamber 300 through the preheating part I and combusts. The combustion gas passes through the heat storage part II of the heat storage bed 200 again, whereby the temperature of the hot combustion gas is reduced by heat exchange with the heat storage part. The combustion gas passing through the heat storage unit passes through the discharge unit OUT of the rotary distribution mechanism 100 and is released into the atmosphere.

In such a combustion facility, the rotary dispensing mechanism 100 intermittently rotates during operation. By the rotation of the distribution mechanism 100, the incoming VOC gas is in communication with the heat storage bed 200 which performed the function of the heat storage unit (Part II) in the previous step, and is preheated by the heat accumulated in the heat storage unit. Accordingly, since the VOC gas flowing into the combustion chamber is introduced in a heated state at a predetermined temperature or higher than the inlet temperature, it is possible to save the amount of heat supplied from the combustion chamber for combustion of the VOC gas.

However, in such a conventional regenerative combustion facility, when the temperature of the incoming gas is high, the lower temperature of the heat storage bed 200 has the same temperature as the incoming gas temperature, and thus the discharged gas temperature is higher than the temperature of the inlet gas (usually, Rise to the inlet gas temperature + combustion temperature x (calculated as 1-heat recovery efficiency). As a result, when the temperature of the inlet gas is high, the temperature of the exhaust gas increases and the energy loss discharged to the outside becomes large.

FIG. 2 is a graph showing a temperature gradient formed by the combustion gas passing through the heat storage unit Part II of the heat storage bed 200 according to the distance from the combustion chamber in FIG. 1.

If the temperature T _I of the incoming VOC gas is about 300 ° C. and the temperature T _E of the combustion chamber is about 850 ° C., the preheating part Part I of the heat storage bed is located in the vicinity of the distribution mechanism and in the combustion chamber. A temperature gradient in the range of 300 ° C. to 850 ° C. is formed between adjacent vicinity. Such a temperature gradient also exists in the heat storage part (Part II) of the heat storage bed, the temperature (T _E ) of the part of the heat storage part (Part II) adjacent to the distribution mechanism 100 is the corresponding portion of the preheating part (process gas inlet Temperature higher than the temperature T _I ). The reason for this is that a high temperature combustion gas passes through the heat storage unit (Part II), and the temperature is expressed by the above-mentioned formula (inlet gas temperature + combustion temperature × (1-heat recovery efficiency)). The combustion gas passing through the heat accumulator (Part II) is released into the atmosphere at room temperature (T _R ) and the temperature drops rapidly.

The higher the temperature of the VOC gas flowing into the combustion plant, the higher the temperature of the combustion gas discharged from the heat accumulator (Part II), and the heat lost when it is released into the atmosphere at room temperature (T _R ). The scale reaches a considerable amount.

In particular, when the regenerative combustion equipment is used to combust unburned gas or VOC gas emitted from incinerators, drying furnaces, carbonization furnaces, etc., which are installed at adjacent locations, the temperature of the incoming process gas is very high, and the temperature emitted is also high, resulting in loss. The amount of heat that is added will increase. This phenomenon is similarly occurred in two- or three-bed regenerative combustion plants as well as nonrotating rotor-type regenerative combustion plants.

Thus, the use of conventional regenerative combustion equipment to combust hot process gases introduced at temperatures above room temperature is undesirable in terms of thermal efficiency.

SUMMARY OF THE INVENTION An object of the present invention is to provide a regenerative combustion facility having improved thermal efficiency in a regenerative combustion facility in which a high temperature inlet gas is used as a process gas and combusts it.

In order to achieve the above technical problem, the present invention accumulates heat from a process gas combusted in a high temperature combustion chamber, and includes a heat storage bed for preheating the incoming process gas. A process gas inflow path for introducing a process gas into the combustion chamber through the heat storage bed, an air inflow path for introducing cooling air at room temperature into the combustion chamber through the heat storage bed, and regenerating the combustion gas burned in the combustion chamber A process gas outlet path for discharging to the outside through a bed, wherein the process gas inlet path, the air inlet path and the process gas outlet path are separated from each other, and the combustion chamber discharges the process gas out of the combustion chamber The regenerative combustion plant further comprises a discharge conduit to The ball.

According to an embodiment of the present invention, the heat storage bed is divided into a preheating part, a cooling part and a heat storage part, and the preheating part, the cooling part and the heat storage part are respectively the process gas inflow path, the air inflow path and the process gas outflow path. Present in the phase.

In the present invention, the combustion facility may include a distribution mechanism for supplying the process gas and air to the preheating and cooling unit of the heat storage bed, and discharge the process gas passing through the heat storage unit of the heat storage bed. At this time, the dispensing mechanism may be a rotor-type dispensing mechanism.

In order to achieve the above technical problem, the present invention provides a heat storage bed including a plurality of sectors divided into at least a preheating unit, a cooling unit, and a heat storage unit, a combustion chamber for burning process gas flowing from the preheating unit of the heat storage bed, A process gas inflow region for introducing a process gas into the preheating portion, an air inflow region for introducing air into the cooling portion, and the heat storage portion from the combustion chamber in correspondence with the preheating portion, the cooling portion, and the heat storage portion, respectively; A rotor-type distribution mechanism intermittently or continuously rotating at a predetermined speed, including a combustion gas outlet region for discharging the combustion gas discharged through the outside and a portion of the combustion gas of the combustion chamber to the outside of the combustion chamber; Provided is a regenerative combustion plant comprising an exhaust conduit installed in a combustion chamber.

In the present invention, the combustion plant further comprises at least one device selected from the group consisting of an incinerator, a carbonization furnace and a drying furnace, wherein the exhaust gas discharged to the discharge conduit is used as a heat source of the device. The flow rate discharged through the discharge conduit may be substantially the same as the air flow rate introduced into the air inlet path.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Figure 3 is a block diagram schematically showing a regenerative combustion plant according to the present invention. Referring to FIG. 3, the regenerative combustion facility includes a distribution mechanism 100 such as a rotor, a regenerative bed 200, and a combustion chamber 300.

In the combustion installation, the rotary distribution mechanism 100 includes an inlet zone IN for the introduction of toxic process gases such as VOC and unburned gas, an air inlet zone Air IN, and a combustion gas discharge zone OUT. It is composed.

The heat storage bed is on an inflow path of the process gas flowing from the inflow region IN of the distribution mechanism 100 and is a preheating part (Part I) for preheating the process gas, and an air inflow region of the distribution mechanism 100. Residual heat from the high temperature process gas present in the cooling unit (Part II), which is present on the inlet path of the air flowing from the air IN and cooled by the inlet air, is discharged on the discharge path of the distribution mechanism 100 It contains a heat storage unit (Part III).

Each region (Part I, Part II, Part III) of the heat storage bed 200 is spatially or physically separated to correspond one-to-one to each region (IN, Air IN, OUT) of the distribution mechanism 100, The process gases or air are not mixed with each other on each path of the combustion plant except the combustion chamber. The separation structure for preventing the mixing of the process gas and the like is well known to those skilled in the art of regenerative combustion equipment, and thus description thereof is omitted.

The process gas introduced into the inlet area IN of the distribution mechanism 100 passes through the preheating part I of the heat storage bed 200 and enters the combustion chamber. A combustion device such as a burner is installed in the combustion chamber to combust the toxic process gas introduced therein. The air at room temperature introduced into the air inlet area Air IN of the distribution mechanism 100 cools the corresponding portion of the heat storage bed while passing through the cooling unit Part II of the heat storage bed, and then enters the combustion chamber.

Some of the process gas and inlet air combusted in the combustion chamber pass through the regenerator (Part III) of the regenerator bed (200), during which the regenerator (Part III) accumulates heat from the hot combustion gas. . The process gas passing through the heat storage unit is discharged out of the facility through the discharge area OUT of the distribution mechanism 100.

The other part of the process gas and the incoming air entering the combustion chamber is discharged through the exhaust conduits installed in the combustion chamber. The discharged gas is supplied to heat sources of peripheral devices such as Theramal Oxidizer, Carbonizer, Dryer, Heat Exchanger and Steam Boiler connected to the discharge conduit. The gas supplied to the peripheral device is discharged after being used as a heat source such as incineration, carbonization, drying, and heating, and when the discharged gas contains noxious gas such as VOC gas or unburned gas, the gas is discharged. May again be introduced into the inlet gas of the combustion plant of the present invention. Of course, alternatively, the exhaust gas of the peripheral device may be directly discharged to the atmosphere.

The combustion equipment of the present invention described above has a higher thermal efficiency than the conventional combustion equipment, which will be described below.

In the combustion plant having a rotor-type distribution mechanism in the heat storage combustion apparatus described with reference to FIG. 3, the process gas inflow region IN and the air inflow region of the distribution mechanism 100 are rotated by the rotation of the distribution mechanism 100. ) And each region (Part I, Part II, Part III) of the heat storage bed 200 corresponding to the process gas discharge region OUT. That is, the heat storage part (Part III) of the heat storage bed 200 of FIG. 3 performs the function of the preheating part (Part I) by the rotation of the distribution mechanism, the cooling unit (Part II) is the heat storage part (Part III) Performs the function of. Here, the cooling unit (the heat storage unit in the current stage) is cooled to at least a portion near the dispensing mechanism 100 by the cold air introduced in the previous stage near the room temperature. Therefore, the discharge temperature of the combustion gas discharged | emitted from the combustion chamber through the said cooling part (heat storage part of a present stage) falls to near room temperature. A drop in exhaust temperature means a reduction in the amount of heat lost, which in turn increases the thermal efficiency of the combustion plant.

In the present invention, air of a sufficient flow rate is supplied to sufficiently cool the cooling unit at the time of cooling the cooling unit (Part II). This makes a functional distinction between the purging gas used in conventional combustion equipment and the air of the invention. In a typical combustion installation, purging is carried out in a short time at a flow rate that purges the gas adsorbed in the preheating stage into the combustion chamber. However, in the present invention, since the cooling of the heat storage bed is an object, a larger flow rate requires that air be introduced for a longer time.

In general, when a low temperature gas is introduced into the combustion chamber in addition to the process gas, more heat is required to raise the temperature to the combustion temperature. This can therefore reduce the efficiency of the combustion plant. However, the combustion plant of the present invention does not discharge all of the gas in the combustion chamber into the atmosphere, but uses some of the gas as a heat source for other devices such as incinerators, carbonization furnaces and drying furnaces. These devices must have a separate heat source, such as a burner, for incineration, carbonization or drying, but can save the energy of the heat source or eliminate the need for the heat source itself by the hot mixed gas coming from the combustion plant.

Equipment such as incinerators, carbonization furnaces and drying furnaces listed are usually installed and operated in conjunction with regenerative combustion plants. This is because installation of the same point is easy to manage because the functional similarity of the removal of harmful wastes is easy, and the regenerative combustion plant often uses the removal of unburned gas or VOC gas discharged from incinerators, carbonization furnaces and drying furnaces.

The combustion equipment of the present invention described above is not limited to the combustion equipment having the rotor type distribution mechanism. The technical idea of the present invention also applies to combustion equipment in which the discharge path of the VOC gas, the air and the process gas is switched in another manner, for example, the inlet path of the process gas, the inlet path of the air, and the discharge path of the process gas through adjustment of the valve. It may be applied, and this does not require any additional knowledge in addition to the common knowledge of those skilled in the art.

4 is a view for explaining the operation of the combustion equipment of the present invention having the rotary distribution mechanism in more detail.

Referring to FIG. 4, the rotary distribution mechanism 100 divides the gas passage cross-sectional area into ten sectors to control the flow of inflow gas or outflow gas. As shown, ten sectors include three sectors of process gas inlet area (In), three sectors of air inlet area (In), three sectors of process gas outlet area (Out), and one sector of dead area (Dead). Divided into. The heat storage bed 200 is also divided into the same number of sectors corresponding to each sector of the rotary dispensing mechanism 100, and each sector of the heat storage bed 200 corresponds to each area of the rotary dispensing mechanism 100. 3 is divided into a preheating unit, a cooling unit, and a heat storage unit.

Of course, the number of sectors shown and the sector allocation to each region are designed in consideration of the processing capacity of the process gas and the required flow rate of the inlet air, and are merely exemplary. As described above, in a combustion facility having the same sector area of the process gas inlet area In and the process gas outlet area Out, the flow rate of air introduced through the air inlet area Air In is different from the incinerator in the combustion chamber 300. It is substantially the same as the flow rate of the gas discharged to the heat source of the apparatus.

Each sector of the heat storage bed 200 is separated from an adjacent sector by a member such as the separating plate 210. The heat storage bed 200 is generally made of a porous ceramic material in terms of heat storage capacity and thermal conductivity.

Hereinafter, the operation of the combustion equipment of FIG. 4 will be described. Process gas flows into the combustion chamber 300 through the process gas inflow area In of the distribution mechanism 100 and the corresponding sector of the preheating part of the heat storage bed (see the solid black arrow). Cooling air flows into the combustion chamber 300 through the air inlet area Air In of the distribution mechanism 100 and the cooling part of the heat storage bed (see the solid blue arrows). Some of the combustion gas in the combustion chamber is discharged into the atmosphere through the heat storage portion of the heat storage bed 200 and the combustion gas discharge area Out of the distribution mechanism 100 (see the dashed arrows). A portion of the combustion gas in combustion chamber 300 is discharged through the exhaust conduit and used as a heat source for a peripheral device such as 400 of FIG.

The air at room temperature (blue solid line) introduced into the cooling unit of the heat storage bed 200 in this gas path keeps the bottom of the heat storage bed close to room temperature by cooling the heat storage bed. Such a low temperature lowers the temperature of the exhaust gas when the cooling unit is switched to the heat storage unit by the rotation of the distribution mechanism 100, and as a result, it is possible to reduce the heat loss of the combustion equipment.

According to the present invention, by sufficiently cooling a part of the heat storage bed by external air during operation of the heat storage combustion equipment, it is possible to lower the temperature of the process gas discharged to the atmosphere. As a result, the heat loss of the regenerative combustion plant can be reduced. The additionally introduced air flow rate may be supplied as a heat source to an incinerator, a carbonization furnace or a drying furnace installed at the same point as the regenerative combustion facility to provide a heat storage combustion facility having high thermal efficiency by minimizing heat loss.

Claims (7)

In a regenerative combustion facility comprising a heat storage bed for accumulating heat from a process gas combusted in a high temperature combustion chamber and preheating the incoming process gas, The regenerative combustion facility includes a process gas inlet path for introducing a process gas into the combustion chamber through the heat storage bed, an air inlet path for introducing cooling air at room temperature into the combustion chamber through the heat storage bed, and combustion in the combustion chamber. A process gas outlet path for discharging the burned gas to the outside through the heat storage bed, wherein the process gas inlet path, the air inlet path, and the process gas outlet path are separated from each other, and the combustion chamber is the combustion chamber. Further comprising an exhaust conduit for discharging the process gas to the outside,  The regenerative combustion apparatus further includes at least one apparatus selected from the group consisting of an incinerator, a carbonization furnace, a drying furnace and a steam boiler, wherein the combustion gas discharged to the discharge conduit is used as a heat source of the apparatus. Combustion equipment. The method of claim 1, The heat storage bed is divided into a preheating part, a cooling part and a heat storage part, wherein the preheating part, the cooling part and the heat storage part are respectively present on the process gas inflow path, the air inflow path and the process gas outflow path. Combustion equipment. The method of claim 2, The combustion equipment includes a distribution mechanism for supplying process gas and air to the preheating portion and the cooling portion of the heat storage bed, and discharges the process gas passing through the heat storage portion of the heat storage bed. The method of claim 3, And said dispensing mechanism is a rotor-type dispensing mechanism. A heat storage bed comprising a plurality of sectors divided into at least a preheating part, a cooling part and a heat storage part; A combustion chamber for combusting process gas flowing from the preheating part of the heat storage bed; A process gas inflow region for introducing a process gas into the preheating portion, an air inflow region for introducing air into the cooling portion, and the heat storage portion from the combustion chamber in correspondence with the preheating portion, the cooling portion, and the heat storage portion, respectively; A rotor-type dispensing mechanism intermittently rotating at a predetermined speed, including a combustion gas outlet region for discharging the combustion gas discharged through the outside; An exhaust conduit installed in the combustion chamber for discharging a portion of the combustion gas of the combustion chamber out of the combustion chamber; And   And at least one device selected from the group consisting of an incinerator, a carbonization furnace, a drying furnace and a steam boiler, wherein the combustion gas discharged to the discharge conduit is used as a heat source of the device. delete The method according to claim 1 or 5, And the flow rate discharged through the discharge conduit is substantially the same as the air flow rate introduced into the air inlet path.

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