JPH0241459Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a deodorizing device for a scrap preheating system using electric furnace exhaust gas, and more specifically, to a deodorizing device for removing bad odors contained in the exhaust gas. . This is used in fields such as scrap preheating equipment, which generates a bad odor from organic substances mixed in when preheating scraps.

[Conventional technology]

When scrap is preheated using high-temperature exhaust gas from an electric furnace, the thermal energy contained in the exhaust gas can be recovered, but on the other hand, organic substances such as oil, paint, and rubber mixed in the scrap evaporate, resulting in foul-smelling exhaust gas. This preheated scrap gas often causes environmental pollution if it is released into the atmosphere, so it is returned to the high-temperature exhaust gas duct immediately after the electric furnace, where it is re-combusted to deodorize it, and then removed from the dust remover. Some substances are released into the atmosphere through chimneys.

However, since the temperature of the exhaust gas after preheating the scrap has been lowered, if this is returned to the high-temperature exhaust gas duct, the temperature of the exhaust gas introduced into the scrap preheater will also be lowered. As a result, not only the desired scrap preheating temperature may not be obtained, but also the generation of bad odor may not be suppressed.

As a device that solved this problem, Japanese Patent Application Laid-Open No. 58-37477
There is a scrap preheating device for an electric furnace described in the above publication. The device includes a temperature equalizer 5 shown in FIG.
is provided upstream of the scrap preheater 7 together with the combustion tower 3 and the high-temperature dust remover 4, etc., and stores and radiates the energy contained in the dust-containing high-temperature exhaust gas generated during refining in the electric furnace 1. Care is taken to ensure that the temperature of the exhaust gas flowing through it is maintained uniform at all times. That is, the exhaust gas introduced into the scrap preheater 7 from one side 6a of the branch pipe 6 is maintained at a predetermined temperature that sufficiently preheats the scrap, and when the preheated exhaust gas flows through the temperature equalizer 5 again, It will be deodorized. Such a temperature equalizer 5 is filled with a heat storage material and has the advantage of not requiring a new heat source for deodorization.

[The problem that the idea attempts to solve]

The electric furnace 1 described above has a break flange 2 to enable its tilting, and outside air enters through the break flange 2 and the duct joints of the combustion tower 3 and high-temperature dust remover 4. Therefore, the temperature inside the temperature equalizer 5 is the temperature necessary for combustion of the malodorous components, for example, 600 to 650.
There is a problem in that the temperature is not maintained at ℃, and deodorization may not be performed sufficiently. In addition, installing a temperature equalizer requires a gravity-settling combustion tower or a cyclone-type high-temperature dust remover to prevent clogging, making it difficult to downsize the entire preheating device. There are also problems.

By the way, Utility Model Application Publication No. 52-37885 and Utility Model Application Publication No. 51
-47574, a gas introduction pipe is connected tangentially at the upper part of a cylindrical container, and a burner for purifying the introduced exhaust gas is attached tangentially to the cylindrical container like the gas introduction pipe. An exhaust gas purification device has been proposed. The flame of the burner is applied to the swirling exhaust gas in such a cyclone-type dust removal device to incinerate the floating unburned materials. Therefore, if the exhaust gas contains malodorous components, they can be removed.

However, even when such an exhaust gas purification device is used as a deodorizing device for a scrap preheating system using electric furnace exhaust gas, the flame is applied to all of the exhaust gas introduced into the cylindrical container to deodorize it. In the scrap preheating system using electric furnace exhaust gas to which the present invention is applied, it is sufficient to deodorize part of the exhaust gas introduced into the cylindrical container that is released into the atmosphere. As long as this is the case, there is a problem that there will be an extremely large amount of waste.

The present invention was developed in view of the above-mentioned problems, and its purpose is to thoroughly mix the foul-smelling exhaust gas generated when scrap is preheated with other exhaust gases, remove dust, and supply the waste gas to the scrap preheater. Deodorization in scrap preheating systems using electric furnace exhaust gas that avoids unnecessary deodorization of exhaust gas, completely deodorizes only the malodorous components contained in exhaust gas released into the atmosphere with a small amount of energy, and avoids environmental pollution. The purpose is to provide equipment.

[Means to solve the problem]

The present invention is applied to an exhaust gas purification device in which a gas introduction pipe is tangentially connected at the upper part of a cylindrical container, and a burner for purifying the introduced exhaust gas is provided.

Its feature is that, with reference to FIGS. 1a and 1b, at least two gas inlet pipes are installed on the upper side of a cylindrical container 20b that is integrated with an inverted conical part 20a that has a dust outlet 21 at its lower part. 22 and 23 are provided in the tangential direction. Two halves of gas discharge pipes 27 and 28 are formed above the gas discharge pipe 24 provided at the center of the upper surface 20c of the cylindrical container 20b. One gas outlet pipe 27 is connected to one of the gas inlet pipes 23 through the scrap preheater 7, and a burner is provided in the other gas outlet pipe 28 for deodorizing the exhaust gas to be released into the atmosphere. 29 is interposed. Further, on the downstream side of this burner 29, an on-off valve 37 for regulating the amount of exhaust gas is provided.

[Effect of idea]

According to the present invention, the scrap preheated foul-smelling low-temperature gas mixed with the dust-containing high-temperature exhaust gas generated in the electric furnace is burned by the burner, thereby avoiding environmental pollution. Further, since at least two gas introduction pipes are provided in the tangential direction on the upper side of the cylindrical container that is integrated with the inverted conical portion, mixing of the introduced exhaust gas and dust removal are effectively performed.
Two gas outlet pipes are also installed to avoid unnecessary deodorization of the exhaust gas supplied to the scrap preheater, while also incinerating and deodorizing only the malodorous components contained in the exhaust gas released into the atmosphere, thereby reducing environmental pollution. In addition to avoiding this problem, it is possible to simplify and downsize a scrap preheating device in which a deodorizing device is employed. Further, by providing an on-off valve for regulating the amount of exhaust gas, the amount of fuel supplied to the burner can be optimally controlled, and the incineration temperature can be easily maintained.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As shown in FIGS. 1a and 1b, the main body 20A of the deodorizing device 20 includes an inverted conical part 20a provided with a dust outlet 21 at the bottom, a cylindrical container 20b integrated with the inverted conical part 20a, and a cylindrical container 20b integrated therewith. Gas introduction pipes 22 and 23 provided on the upper side of the container 20b and the container 20
It has a cyclone-type structure consisting of a gas exhaust pipe 24 and the like provided in the center of the upper surface 20c.

The gas introduction pipe 22 is a high-temperature exhaust gas duct 3 through which high-temperature exhaust gas from the electric furnace 1 flows as shown in the system diagram of FIG.
1 via an introduction duct 32, and
The gas inlet pipe 23 is connected to a duct 33 from the outlet of the scrap preheater 7. Former introduction pipe 2
2, the dust-containing high-temperature exhaust gas generated in the scrap refining process of the electric furnace 1 is introduced into the main body 20A, and from the latter introduction pipe 23, the low-temperature exhaust gas that has been preheated by the scrap preheater 7 is introduced into the main body 20A. ing.

The fixed positions and directions of the gas introduction pipes 22 and 23 are determined in order to obtain the swirling flow necessary for mixing the respective exhaust gases introduced by them and removing dust.
They are adjacent to each other at the same level near the top of the side surface of the container 20b, and are tangential to the inner wall of the container 20b that is lined with a refractory material (not shown). Note that the gas discharge pipe 24 for discharging the mixed exhaust gas is connected to the container 20 as shown in FIG. 1a.
If the heat storage material 25 is filled in the heat storage material 25 when the heat storage material 25 is installed in the scrap preheater 7, heat exchange will occur between the heat storage material 25 and the mixed gas. It is possible to exhibit a temperature equalization function that maintains the gas and exhaust gas released into the atmosphere at a substantially constant temperature at all times.

At the upper part of the above-mentioned gas discharge pipe 24, there is a gas discharge pipe 2 divided into two by a partition plate 26 as shown in FIG.
7 and 28 are formed, and are connected to a duct 34 shown in FIG. 2 and a duct 35 described later, respectively.
In one of these gas outlet pipes, the gas outlet pipe 28, in order to prevent bad odors from being released into the atmosphere.
A burner 29 is installed to burn malodorous components in the exhaust gas, and open/close valves 36 and 37 are provided in the high-temperature exhaust gas duct 31 and the duct 35, which are opened and closed as necessary to release the deodorized odorless gas into the atmosphere. .

By the way, since the combustion by the burner 29 is only necessary for deodorizing, the main body 2 may fluctuate to some extent.
If combustion control is performed in accordance with the exhaust gas temperature from 0A, fuel consumption can be suppressed. Therefore, in this example, the duct 3 downstream of the burner 29
A temperature sensor 38 is installed inside the fuel tank 5, and the opening degree of a fuel supply valve (not shown) is adjusted based on the detected value. Also, consideration has been given to supplying secondary air for combustion as needed. Note that the mixed gas in the main body 20A is divided into two parts downstream of the gas discharge pipe 24, and as shown in FIG.
The other part is led out to the scrap preheater 7 via a duct 34, and after the scrap preheating is completed, it can be returned to the main body 20A by an induction fan 39 interposed in the duct 33.

According to the embodiment configured as described above, it is possible to remove the bad odor generated due to scrap preheating by operating as follows.

As shown in FIG. 2, when the electric furnace 1 is operated,
Dust-containing high-temperature exhaust gas is generated as a result of scrap refining, and this exhaust gas is led out to the high-temperature exhaust gas duct 31 from the gas outlet 1a. When the opening degrees of the on-off valves 36 and 37 are adjusted appropriately, the duct 31 and the introduction duct 3
Although the ratio of gas distribution to the electric furnace 1 can be changed, only the on-off valve 36 is opened when the electric furnace 1 is operated without preheating the scrap.
Then, unburned components in the dust-containing high-temperature exhaust gas are combusted in the gravity settling type combustion tower 3 interposed in the high-temperature exhaust gas duct 31, and are attracted by the induction fan 40, passed through the dust remover 11, and then released from the chimney 12. .

On the other hand, when preheating scrap, on-off valve 3
The opening degrees of 6 and 37 are adjusted to match the operation of the electric furnace 1, and the above-mentioned dust-containing high-temperature exhaust gas is introduced into the introduction duct 3.
2 is introduced into the main body 20A via a gas introduction pipe 22 (see FIG. 1a). On the other hand, the preheated exhaust gas with bad odor that has passed through the scrap preheater 7 and whose temperature has been lowered by preheating the scrap is transferred to the induction fan 3.
9 is introduced into the main body 20A via the gas introduction pipe 23. As described above, both the gas introduction pipes 22 and 23 are fixedly installed in the tangential direction of the cylindrical container 20b of the deodorizing device 20, so that both exhaust gases having a temperature difference form a swirling flow in the direction of arrow M within the container 20b. becomes. As a result, the exhaust gases are mixed, a certain amount of malodorous components are burned, and the dust in the mixed gas is removed by centrifugal force.

The dust descends along the inner surface of the container 20b and accumulates in the dust outlet 21 and the inverted conical portion 20a, and is removed by opening the gate 30 at an appropriate time. The mixed gas from which dust has been removed is reversed in the direction of arrow N, and then passed through the gas exhaust pipe 2.
4, and if a heat storage material 25 is interposed in the gas discharge pipe 24, the mixed gas exchanges heat with it. For example, if the mixed gas is higher in temperature than the heat storage material 25, heat is given to it, and if it is lower in temperature, heat is received from the heat storage material 25, the temperature of the mixed gas is equalized, and combustion in the burner 29 is reduced. Heat storage material 25
The mixed gas that has passed through the gas discharge pipe 24 is divided into two by a partition plate 26 at the upper part of the gas discharge pipe 24.
8 and the mixed gas in the gas outlet pipe 27 is
It is introduced into the scrap preheater 7 through the duct 34 to preheat the scrap.

The scrap preheater 7 includes, for example, preheating baskets 7a and 7 arranged in parallel as shown in FIG.
By appropriately selecting the opening and closing of the upstream and downstream on-off valves, the scraps are always preheated to a desired temperature in either one of the preheating baskets 7a and 7b. On the other hand, the mixed gas containing residual malodorous components in the gas outlet pipe 28 is led out to the duct 35, and the amount of fuel supplied to the burner 29 is controlled according to the temperature of the exhaust gas flowing through the duct 35 detected by the temperature detector 38. Even if the outside air is sucked in from break flange 2 and the temperature is slightly lower, the temperature remains at 600°C, which is suitable for deodorization.
The temperature is maintained at ~650°C, and excessive fuel consumption is suppressed.

Deodorizing with this burner is not performed on all the exhaust gas introduced into the deodorizing device 20, but only on the exhaust gas released into the atmosphere. Therefore, the incineration of malodorous components is kept to the minimum necessary limit, and in combination with flow rate control, energy-saving operation is possible.

To explain in more detail, preheating the scrap requires a large amount of waste heat, but the amount of malodorous components in the exhaust gas is extremely small. To keep this large volume of waste heat at a temperature suitable for deodorization (600-650℃),
As disclosed in Japanese Patent Application Laid-Open No. 58-37477, a large capacity burner is required. However, in this invention, the second
In the system shown in the figure, the on-off valve 37 is throttled at the beginning of scrap preheating to reduce the amount of exhaust gas containing malodorous components released into the atmosphere, and preheating proceeds while saving energy for the burner, increasing the concentration of malodorous components in the exhaust gas. By opening the on-off valve 37 and increasing the amount of heat of the burner, the malodorous components can be efficiently burned. In addition, the deodorized harmless exhaust gas is extracted from the induction fan 4.
0, and is emitted from the duct 35, through the high-temperature exhaust gas duct 31, and the dust remover 11, and from the chimney 12 into the atmosphere.

In this way, in a scrap preheating device using a deodorizing device, the exhaust gas released into the atmosphere is deodorized and environmental pollution is avoided, and energy saving is achieved by scrap preheating. Dust is removed and the quality of the steel is improved, and furthermore, contamination of the working environment due to dust scattering is prevented. In addition, when the deodorizing device functions as a combustion tower, a high-temperature dust remover, and a temperature equalizer, the entire preheating device can be simplified and miniaturized. Note that even if the configuration is appropriately changed, such as by employing a deodorizing device that does not have a temperature-uniforming function, the same or similar effects as those described above can be achieved.

As can be seen from the embodiments described in detail above, in the present invention, a gas outlet pipe divided into two is formed at the upper part of a gas outlet pipe provided at the center of the upper surface of the container, and the atmosphere is contained in either one of the gas outlet pipes. Since a burner is used to deodorize the exhaust gas emitted into the furnace, if it is applied to the scrap preheating device of an electric furnace, it will deodorize the scrap preheated exhaust gas mixed with the dust-containing high temperature exhaust gas generated in the electric furnace. Of these, only the foul-smelling low-temperature gas released into the atmosphere is burned by the burner, and environmental pollution can be avoided with minimum energy consumption. In addition, at least two gas introduction pipes are provided tangentially on the upper side of the cylindrical container that is integrated with the inverted conical part, so that the introduced exhaust gas is effectively mixed and dust removed, and the deodorizing device is The adopted scrap preheating device, etc. will be simplified and miniaturized.

[Brief explanation of the drawing]

Fig. 1a is a sectional view of the deodorizing device of the present invention, Fig. 1b is a sectional view taken along the - line in Fig. 1a, Fig. 2 is a system diagram of a scrap preheating device for an electric furnace to which this deodorizing device is applied, and Fig. 3 The figure is a system diagram of a conventional scrap preheating device for an electric furnace. 7... Scrap preheater, 20... Deodorizing device,
20a...inverted conical part, 20b...cylindrical container, 2
0c...Top surface, 21...Dust outlet, 22,2
3...Gas introduction pipe, 24...Gas discharge pipe, 27,
28... Gas outlet pipe, 29... Burner, 37...
Open/close valve.

Claims (1)

[Scope of Claim for Utility Model Registration] In an exhaust gas purification device in which a gas inlet pipe is tangentially connected at the upper part of a cylindrical container and a burner is provided to purify the introduced exhaust gas, there is a dust outlet at the bottom. At least two gas inlet pipes are provided in the tangential direction on the upper side of the cylindrical container that is integral with the inverted conical part provided with the container, and are bisected at the upper part of the gas exhaust pipe provided in the center of the upper surface of the container. One gas outlet pipe is connected to one of the gas inlet pipes through a scrap preheater, and the other gas outlet pipe is provided with a gas outlet pipe for deodorizing the exhaust gas to be released into the atmosphere. 1. A deodorizing device for a scrap preheating system using exhaust gas from an electric furnace, characterized in that a burner is interposed, and an on-off valve for regulating the amount of exhaust gas is provided downstream of the burner.