JPS6023248B2 - Combustible exhaust gas combustion treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention utilizes the oxidation reaction heat generated during combustion treatment of exhaust gas containing flammable particulates such as phenol and organic solvents to preheat exchange heating of new combustible exhaust gas before treatment. The present invention relates to a combustible exhaust gas combustion treatment device that thermally manages the preliminary heat exchange temperature to a certain level or below, regardless of the phenomenon of abnormally high temperature of oxidation reaction heat accompanying an increase in the concentration of combustible particulates in the case of reuse heat recovery.

-This type of conventional combustible exhaust gas cleaning treatment includes direct combustion, catalytic, adsorption,
There are various types such as the water washing type, but the direct combustion type in particular is generally evaluated as having the lowest equipment cost and the most stable treatment efficiency, but on the other hand, the treatment temperature is 700℃ ~
The operating cost is as high as 80ppm, and the running cost is the highest, and it also has the drawback that abnormal high temperature phenomena occur depending on the amount of oxidation reaction heat, and the operation is stopped each time, resulting in a decrease in the operating rate.

In order to compensate for the shortcomings in operating fuel efficiency, it would be good to adopt a heat exchanger with high heat exchange and efficiency, but since the structure of the conventional direct combustion combustion treatment device A is designed as shown in Figure I. , the direct-combustion type combustion treatment equipment may experience an abnormally high temperature phenomenon due to the temperature increase due to the heat of oxidation reaction generated due to the high concentration of combustible particulates (organic solvents, etc.) contained in the combustible exhaust gas, resulting in a dangerous situation. As a result, the current situation is that heat exchange efficiency cannot be improved in any way. In other words, if we systematically look at the process of occurrence of abnormally high temperature phenomena in Figure 1, we can see that, for example, temperatures ranging from 100 to 30
000 combustible exhaust gas enters the preheat exchanger 2 from the receiving duct 1 and is preheated.The heating temperature there varies depending on the heat exchange efficiency, but for example, if the efficiency is 45%, the temperature after passing through the preheat exchanger 2 is The crossover duct 3 is flooded to about 40 to 500 points.

The combustible exhaust gas is further led to a main heating chamber 5 equipped with a burner 4, where it reaches an oxidation reaction temperature 7, which is the combustion temperature of the combustible particulates.
When the exhaust gas is heated from 0 to 80 degrees Celsius and enters the next full reaction chamber 6, the temperature of the exhaust gas that comes into contact with and passes through the detection part of the temperature detector 7 installed in the end of the retention reaction chamber 6. is always 70
The combustion amount of the burner 4 can be controlled to a constant temperature within the range of 0:00 to 800:00 using the side temperature value signal sl from the temperature detector 7.
700q in the retention reaction chamber 6, which performs automatic feedback process control by adjusting the valve opening and restriction of the on-off valve (not shown) attached to the burner 4 to meet the target set value.
If an atmosphere of 0 to 800 qo is maintained for 0.4 to 0.7 seconds, the combustible particulates in the exhaust gas will accelerate the oxidation reaction, and the oxidation reaction will be reduced by 99%.
The above is thermally decomposed into water and carbon dioxide and converted into clean gas. As the clean gas passes through the preheating chamber 8, its heat is recovered by the preheat exchanger 2, and then released from the exhaust stack 9 to the atmosphere. However, when a large amount of combustible particulates, which are a disturbance factor, are sent into a place where the feces temperature is controlled at 750 degrees Celsius due to overflow in the simmering reaction chamber 6, they undergo an oxidation reaction one after another in the simmering reaction chamber 6. It is excited, but at that time, due to oxidation reaction, 8
A large amount of reaction heat is generated, amounting to 00,000 to 1,200,00 plates M/day.

Due to this reaction heat, the temperature of the retention reaction chamber 6 rises rapidly.
It reaches 100-1300℃. In this case, naturally, the feedback process control system for the burner 4 operates to throttle the burner 4 to the minimum combustion amount.
The 300°C high-temperature clean gas is transferred to the preheat exchanger 2 in the preheating chamber 8 for heat transfer recovery, and a large amount of combustible exhaust gas is transferred from the drying furnace passing through the preheating exchanger 2. This causes heat propagation and causes the exhaust gas temperature in the crossover duct 3 to overflow to 550 to 65 picC. Even if the burner 4 is reduced to the minimum combustion amount to suppress heating in the main heating chamber 5. The heat of the oxidation reaction within the retention reaction chamber 6 causes an abnormally high temperature of 1100 to 1300 oo, which is extremely dangerous. That is, in general, in the case of a direct combustion type treatment device, the allowable temperature limit of the moat reaction chamber 6 is 900°C to 95,000°C.
1100qo~1300℃ exceeding this
When the temperature reaches 250 oo, the exterior part is at risk of fire, and when the temperature rises to 1,100 qC to 1,300 qo, the thermal expansion of the stagnation reaction chamber 6 is large, causing thermal distortion, which may cause deformation or destruction of the stagnation reaction chamber 6. . Furthermore, when the temperature of the retention reaction chamber 6 rises to 1100°C to 1300°C, the preliminary heat exchanger 2 applies heat to the new flammable gas coming from the drying oven, so the temperature inside the crossover duct 3 rises to 550°C to 650°C. It rises to ℃. When this temperature is reached, some of the combustible particulates contained in the exhaust gas, which tend to undergo oxidation reactions even at relatively low temperatures, begin to undergo oxidation reactions. This oxidation reaction triggers an oxidation reaction of other combustible particulates in the crossover duct 3, although the reaction should originally take place in the stagnation reaction chamber 6. In short, the place where the reaction occurs gradually moves closer to the drying oven. The most dangerous situation is that if this reaction occurs in the receiving duct 1 that sends the exhaust gas from the drying furnace, a fire will occur in the receiving duct 1 that has not been specially heat-resistant treated.

The present invention solves the conventional drawbacks and improves the heat exchange efficiency of the preheat exchanger, and also provides a combustible exhaust gas combustion treatment system that significantly improves burner fuel efficiency and increases operational availability. That is.

A first embodiment of the device of the present invention will be described with reference to FIG.

The combustible exhaust gas combustion treatment apparatus B of the present invention is a conventional direct combustion type combustion treatment apparatus A shown in FIG.
A bypass stack 10 that can be automatically opened and closed to connect with outside air is provided at the end, and inside the bypass stack 10 there is a temperature sensor 11 placed near the boundary between the retention reaction chamber 6 and the preheating chamber 8. Modutrol motor 1 that converts the excess overheating change in temperature value signal s2 into rotational torque for opening adjustment.
A bypass control bumper 13 directly connected to the preheating chamber 8 and a manually fixed load adjustment damper 14 that generates a loss comparable to the pressure loss in the preheating chamber 8 are vertically combined and pivoted to freely adjust the opening rotation. , a temperature sensor 11 is installed in the exhaust stack 9 in synchronization with the temperature adjustment operation of the bypass control bumper 13 of the bypass stack 10.
Losses from.

A stack control damper 16 is directly connected to a module control motor 15 that converts the excess overheating change of the temperature value signal s3 into rotational torque for adjusting the closing degree, and is pivotally supported to freely adjust the opening degree. Similar to the temperature detector 7 of the device A, the valve opening/closing degree of an on-off valve (not shown) attached to the burner 4 can be adjusted according to the temperature reduction value signal sl from the temperature detector 11, and the burner 4 and the bypass stack 1 can be freely adjusted.
The opening/closing degree of the open/close valve (not shown) of the exhaust stack 9, the bypass control bumper 13, and the stack control damper 16 is adjusted within the retention reaction chamber 6 and the preheating chamber 8.
The system is constructed such that proportional operation can be controlled point by point in a concentrated manner using the received temperature value signals sl, s2, and s3 from the temperature detector 11 with the detecting part 11a exposed near the boundary between the inside and outside. Note that the same parts as those in the conventional direct combustion combustion processing apparatus A are given the same reference numerals.

The functions and effects of the device B of the present invention will be explained below.

A large amount of combustible particulates that have come to the retention reaction chamber 6 undergo an oxidation reaction, and the temperature inside the retention reaction chamber 6 rises.

When this temperature exceeds 800°C, the bypass control bumper 13 is automatically opened under proportional control based on the leakage temperature value signal s2 of the temperature detector 11, and at the same time, the bypass control bumper 13 is opened to release the high temperature treated exhaust gas to the atmosphere.
3, the stack control damper 16 is automatically closed by the required amount under proportional control so that the required amount of exhaust gas can be smoothly discharged. When the temperature inside the bottom reaction chamber 6 returns to 75,000 by releasing excess heat to the atmosphere, the bypass control bumper 13 is fully opened and the stack control damper 16 is fully opened. In order to release excess heat, it is sufficient to provide only the above two dampers 13 and 16, but in this case, if some of the excess high temperature gas is released from the bypass control bumper 13, the conventional flow of exhaust gas is reduced to stagnation. Reaction chamber 6, preheating chamber 8, exhaust stack 9
What used to be discharged through the exhaust gas is now discharged through the stagnation reaction chamber 6 and the bypass stack 10, and the pressure loss imparted to the exhaust gas by the preheat exchanger 2 is eliminated. This means that the value of the pressure loss of the combustible exhaust gas in the preheat exchanger 2 changes greatly depending on the increase or decrease in the amount of exhaust gas passing through the preheating chamber 8. If this pressure loss becomes excessive, the drying furnace, which is the source of the flammable exhaust gas to be treated, will not be sufficiently vented, leading to an explosion in the drying furnace. When the pressure loss given to the exhaust gas decreases, the static pressure inside the enrichment reaction chamber 6 decreases, which causes an increase in the amount of exhaust gas from the drying oven (not shown), which is the source of flammable exhaust gas, and - This will disrupt the conditions.

In particular, when the drying oven is a drying oven for metal printing, the operating conditions are severe, and fluctuations in the exhaust gas flow rate must be kept within ±10% of the specifications. The load adjustment damper 14 is provided to suppress fluctuations in the amount of exhaust gas storm. This damper 14 is opened to compensate for the exhaust gas pressure loss (50 to 10 mAq) in the preheat exchanger 2 during a test run of the device so that the load adjustment damper 14 can be closed by the required amount to obtain the same pressure loss. Set and fix. A feature of device B of the present invention is that the variation in air volume can be suppressed to within 5%.
In addition, since the opening and closing of the two control dampers 13 and 16 is done by proportional control using the Modutrol motors 12 and 15, it is possible to go from fully open to fully closed in about 19 seconds, and therefore the air volume can be reduced. It also has the advantage of requiring little fluctuation in . In addition, by providing the bypass stack 10 to release excess heat, the temperature inside the retention reaction chamber 6 can be reduced to 7000.
As a result of being able to control the temperature within the range of 0 to 780 qo, the temperature inside the crossover duct 3 has also decreased to 400 C0 to 50,000 qo.
protected by

Therefore, if the temperature is around this level, there is no possibility that the combustible particles in the exhaust gas will cause an oxidation reaction, so there is no fear of an oxidation reaction occurring in the receiving duct 1, and there is no fear of fire. Moreover, as explained earlier, the temperature inside the total distillation reaction chamber 6 can actually be maintained at 70,000 to 780 oo,
This can hardly be called a high temperature compared to the usual 750 qo.

For example, if the exhaust gas flow rate is 130N/m
If 6 eggs (50%) of ln are discharged/min with 10 bypass stacks, approximately 943,000K/day of heat will be released. This means that the exhaust gas 13/min coming from the drying furnace is no longer preheated.
The amount of heat = temperature x ripeness x air volume. Therefore, the amount of heat given to the next exhaust gas by the preheat exchanger 2 is halved, and the temperature inside the crossover duct 3 will no longer rise to 55 to 650 degrees Celsius. . The following table shows a comparison between the conventional device A and the device B of the present invention through specific experimental examples of the present invention.

The device B of the present invention was tested and found that it was possible to prevent the occurrence of abnormally high temperatures under the above conditions, and the temperature inside the retention reaction chamber 6 was also 70.
Stable processing is possible in the range of 0 to 78 pi 0, and the fluctuating amount of exhaust gas supplied to the drying oven is 125 to 13 p/m.
It was also found that the speed was as low as 13 min/min (normal time).

It was confirmed that the combustible exhaust gas combustion treatment apparatus of the present invention can stably treat exhaust gas such as vinyl paint.

In parallel, the preheat exchanger efficiency of the device of the present invention was increased to 7.
It has excellent effects, such as making it actually possible to raise things by 0%. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a conceptual structural diagram of a conventional road combustion type combustion processing device, and FIG. 2 is a conceptual structural diagram showing a first embodiment of the combustible exhaust gas combustion processing device of the present invention.

B... Combustible exhaust gas combustion treatment device, sl, s2, s
3... Column temperature value signal, 1... Receiving duct, 2
...Preliminary heat exchanger, 3 ... Crossover duct, 4 ... Burner, 5 ... Main heating chamber, 6 ... stagnation reaction Chamber, 8...Preheating chamber, 9...Exhaust stack, 10...Bypass stack, 11...Temperature detector, 11a
...Detection unit, 12, 15...Modutrol motor,
13... Bypass control bumper, 14...
...Load adjustment damper, 16...Stack control damper.

Figure 1 Figure 2

Claims (1)

[Claims] 1. Combustible exhaust gas is transported from the reception duct to the preliminary heat exchanger, crossover duct, main heating chamber equipped with a burner that can automatically adjust the combustion power, retention reaction chamber, and preliminary heat exchanger equipped with the above-mentioned preliminary heat exchanger. In a direct combustion type combustion processing apparatus of an integrated system in which clean gas is discharged into the atmosphere from an exhaust stack through a chamber sequentially, the detection section is installed at the end of the stagnation reaction chamber and connected to the stagnation reaction chamber and the preheating chamber. The bypass control bumper is directly connected to the module troll motor that converts the excess superheat change in the temperature value signal from the temperature sensor exposed near the boundary into rotational torque for opening adjustment, and the exhaust gas pressure in the preheat exchanger. A bypass stack having a load adjustment bumper to suppress losses as much as possible is provided at the end of the retention reaction chamber, and the temperature sensor A stack control damper is provided in the exhaust stack, which is directly connected to a module troll motor that converts the excess overheating change in the temperature measurement signal from the burner into rotational torque for adjusting the degree of closure, and an on-off valve for adjusting the combustion power of the burner. and a combustible exhaust gas combustion processing device, wherein the opening and closing of the bypass control bumper and the stack control damper can be synchronously and centrally controlled one by one in proportion to the temperature of the exhaust gas using the measured temperature signal.