KR880001687B1 - Pressure regulator for opening section of discharge for baked material in continuous air-current baking furnace - Google Patents

Abstract

The device (1) provides an opening to discharge burnt substance at the bottom of the upside-down cone section and an opening area adjusting means. The device can adjust pressure at the opening to a little positive pressure to cope with various conditions and adjust residence amounts to cope with variations in material particle size and amount of charge.

Description

Pressure regulating device of plastic discharge opening in continuous air kiln

1 is a longitudinal sectional view showing an outline of an upright air flow kiln using the apparatus of the present invention.

2 to 4 are longitudinal cross-sectional views showing the positions of the respective discharge containers.

Fig. 5 is a longitudinal sectional view showing the outline of the fired matter discharge opening, the discharge container and the area control device of the opening of the present invention.

Figure 6 is a schematic diagram showing a general ventilation system of the air flow kiln.

* Explanation of symbols for main parts of the drawings

1: air flow kiln 2: combustion gas outlet

3: powder inlet 6a: to

6d: Inlet port of sidewall combustion gas etc. 7: Inlet box of lower combustion gas etc.

8: plastic discharge container 9a: large diameter upright cylindrical part

9b: small diameter upright cylindrical part 10b: inverted cone shape (inverted cone shape)

11 settling chamber 12 junction

13: plastic discharge opening 15: opening area control device

16 opening pressure detector tube 18 plastics

The present invention relates to a pressure regulating device of a fired product discharge opening in a continuous air flow kiln of an upright ball tower structure for firing a granulated material.

The inventors of the present invention have previously restricted the continuous air firing furnace of the upright tower structure and the air firing method using the firing furnace in Japanese Patent Application Laid-Open Nos. 57-1436 and 57-28982. In the case of), the relationship between the feed amount of the raw material, the particle size of the raw material, and the retention amount in the furnace is limited to a specific range, which makes it difficult to stabilize the furnace state in response to a wide range of conditions. .

Here, the outline of this technique proposed above will be explained according to FIG. 1, and the powder raw material is supplied from the inlet port 3 of the air-firing furnace 1 to transfer fuel, air or combustion gas (hereinafter referred to as combustion gas). It is fed from the mouths 7 and 6a to 6d to form a fired layer by rising air to discharge the fired product from the discharge vessel 8 of the inverted cone portion 10a and to discharge the combustion exhaust gas from the discharge port 2. It is the furnace of the structure to discharge.

And it is characterized by the installation of a sinking chamber (11) having a slow flow rate of the rising air in the upper part of the furnace to prevent the raw material or burned material with the combustion exhaust gas, and then to the mixture of the rising air and the granules (this In the technique, the granular material means a layer in which it floats, circulates, and flows due to an air stream.) The granular material is held in a furnace for a predetermined time, and then fired while gradually falling.

At this time, the flow velocity of the rising air is small in the mixed layer 4 (large diameter upright cylindrical portion 9a) and the flow velocity is large in the mixed layer 5 (small diameter upright cylindrical portion 9b). A rich mixed layer having a large concentration is formed, and a lean mixed layer is formed in the mixed layer 5.

Because of the furnace having such a structure, the mixed layer 5 can be fired at the highest temperature range, and a temperature difference occurs between the mixed layers 5 and 4, resulting in high thermal efficiency. Another characteristic is that the granular material continuously fed into the furnace is less discharged from the top of the furnace because of the settling chamber at the top of the furnace. After the supply of raw materials continues to fall, the balance falls gradually to the point where the balance is collapsed, and is discharged and discharged directly to the outside of the furnace while being floated and transferred without being deposited on the bottom of the furnace.

As described above, in this technique, the discharge of the fired products does not flow out like a general flow path, but is directly connected to the lower part of the furnace floor as in the case of studying at No. 57-91093. It is neither a dropping nor discharge of a fired product to the apparatus, but a technique of opening and discharging the fired product directly out of the furnace directly from the fired discharge container. It supports the desired weight of suspended solids (this is equivalent to the pressure loss in the furnace as described below) and is also balanced by the pressure near atmospheric pressure at the discharge opening of the fired material (2) Pressure is applied to the outlet opening to maintain the temperature at the firing zone of the mixed bed 5 close to the outlet at a constant and continuous discharge. It will make it valid for slightly positive pressure (正壓) is required at.

This condition can be realized in the technique of the source shown in Fig. 1 by appropriately disposing the opening and operating method of the discharge opening. However, if the particle size and / or feed amount of the raw material is changed, the amount of retained particles in the furnace is increased or decreased. The pressure loss of the rising air changes. In addition, since the pressure of the discharge opening changes and leaves the stable area, it is necessary to adjust the pressure of the discharge opening and the amount of retention in the furnace that can cope with the change of the conditions.

In order to solve these problems, the present inventors have studied in various ways a correlation between the discharge mechanism of the fired material, the position of the discharge opening, the change in the retention amount of the granules in the furnace, the change of the raw material particle size and the pressure of the discharge opening. These results will be described below, but the general operation overview of the pressure regulation of the conventionally known outlet opening in this technology will be described.

FIG. 6 is an example of the schematic diagram which shows the supply of fuel, air, etc., and the ventilation system of combustion gas in operation of this airflow kiln.

In the figure, 19 is a blower, 20 is a damper for adjusting the blowing amount, 21 is a blower tube, 22 is a fuel gas tank, 23 is a combustion gas pipe, and 24 is a valve 29. 30 is an exhaust fan, 31 is a damper for adjusting the suction force of the exhaust fan, and 32 is a combustion gas exhaust pipe.

There is no problem as long as it is possible to operate the furnace at a static pressure higher than atmospheric pressure, but in this furnace, since the plastic discharge vessel is open to the atmosphere, it is necessary to adjust the pressure slightly near the atmospheric pressure in the discharge opening as described above. .

In actual operation, the amount of blown air and the amount of fuel gas are adjusted to a predetermined amount by opening and closing the damper 20 and the valves 24 to 29, and the pressure adjustment of the discharge opening is performed by opening and closing the damper 31.

That is, in the direction of opening the damper 31, the suction force of the air blower 30 is increased, the negative pressure is increased by that much. In the closing direction, the suction force decreases, so that the inside of the furnace overcomes the blowing pressure of the blower 19 and increases in the static pressure.

Therefore, in general, the distribution of the internal pressure of the furnace is controlled by adjusting the suction force of the exhaust fan 30 by opening and closing the damper 31.

Next, the above-described soft result will be described.

First, as shown in FIG. 2, when the discharge cylinder 8 is provided above the joint portion 12 between the inlet cylinder 7 such as combustion gas and the inverted cone portion 10b, the desired granular material stays in the furnace. For this purpose, it has been found that the pressure of the discharge opening 13 is negative. As a result, since the outside air is sucked into the discharge container 8, the amount of airflow in the furnace is increased, the mixed layer 5 is cooled, and it is difficult to maintain the maximum temperature, and the temperature distribution in the furnace is changed.

At this point, in order to make the pressure of the discharge opening part slightly static pressure, for example, the damper 31 of the apparatus shown in FIG. 6 is adjusted in the closing direction, the suction force by the blower 30 is reduced. I found out that the sieve could not be kept in the furnace.

In the case of FIG. 3, the position of the discharge cylinder 8 is installed in the delivery cylinder 7 of combustion gas etc. which are lower than the junction part 12. In FIG. In this case, since the flow velocity of the rising air, such as combustion gas, in the delivery container 7 is more than the terminal speed of a granular material, a burned material does not drop-discharge.

Therefore, the fired matter floats and accumulates around the lower portion of the inverted cone portion 10b, but when it exceeds a certain amount, it cannot be supported by the rising air from the inlet 7 of the combustion gas or the like, and the static pressure at the outlet opening becomes large. And the pulsating product falls pulsatingly and is discharged from the discharge container 8. Therefore, continuous quantitative discharge is impossible and the furnace is not stable.

In the case of FIG. 4, when the position of the discharge container 8 is installed through the junction 12, in this case, it is possible to keep the desired amount of stay, to maintain an appropriate furnace temperature distribution, and to make the pressure of the discharge opening slightly constant. Quantitative discharge rates are also possible. However, the scope of operation is narrow for the industry. For example, when the particle size of the raw material is changed from large to small, the amount of retention in the furnace increases and the pressure of the discharge opening increases, so that the above-mentioned condition of setting the pressure of the discharge opening to slightly static pressure cannot be satisfied. In addition, if the change in the particle size is opposite to this, the opposite result is difficult, and therefore it is difficult to perform a stable labor operation corresponding to the change in the particle size of the raw material.

Thus, the present inventors have examined the experimental results, etc., and as a result, the air flow kiln according to this technique is provided by installing the discharge opening of the plastic product in the lower portion of the inverted cone portion 10b through the junction 12 and adjusting the area and space of the opening. ; (1) It is easy to make the pressure of the discharge opening part a little static pressure, and (2) It is necessary to adjust the pressure of the discharge opening part or to adjust the retention amount to increase or decrease the retention amount in response to the change in the particle size of the raw material and to perform a stable operation. I found it possible.

The present invention is based on this knowledge, a large diameter upright cylinder connected to each other through an inverted conical section connected to the bottom of the sedimentation chamber, the sedimentation chamber of the granular material inlet installed in the upper part of the upright furnace of the tower structure. A portion of a small-diameter upright cylindrical portion, a plastic discharge cylinder installed through the inverted conical portion below the small-diameter upright cylindrical portion, and a plurality of combustion gases provided in the small-diameter upright cylindrical portion and the inverted conical portion below it. In an inlet continuous air kiln, fuel. The fired product discharge opening 13 is provided in the lower portion of the reverse cone 10b through the junction 12 between the inflow cylinder 7 such as air or combustion gas and the reverse cone 10b. A pressure regulating device for a fired product discharge opening in a continuous air flow kiln, characterized in that a fired product discharge container 8 and an area adjusting device 15 of this opening portion are provided in 13).

Next, the structure of this invention is demonstrated with the action according to an Example.

5 is an example of implementing the present invention. The fired product discharge opening 13 is placed in the lower portion of the reverse cone portion 10b through the junction portion 12 of the reverse cone portion 10b below the small diameter upright cylinder portion 9b and the delivery cylinder 7 such as combustion gas. It installs and the plastic discharge container 8 is installed in this opening part.

In the figure, reference numeral 17 denotes a cover that can be freely opened and closed by discharging the fired material installed at the distal end of the discharge port, and reference numeral 18 denotes the discharged fired product. And this opening part 13 is provided with the cylindrical area control apparatus 15 which can slide in the outer cylinder 14. As shown in FIG. As the cylindrical area control device 15 enters and exits along the outer cylinder 14, the furnace section area and the space (volume) at this position are wide or narrow at the position of the discharge opening 13. This area control device 15 has a hole at the tip and can measure the positive pressure of the discharge opening by the pressure detection tube 16.

As described above, in the proper operation of the air-fired furnace, it is necessary to adjust the pressure of the discharge opening and the amount of retention in the furnace in response to various conditions changes, but the following describes the adjustment using the present invention.

In other words, the pressure of the outlet opening in the air-firing furnace is determined by the positional relationship between the inlet 7 of the combustion gas and the fired discharge outlet 13 and the pressure of the outlet opening through the joint 12 is provided. It is easy to make the pressure slightly static. In addition, in order to adjust the pressure of the outlet opening slightly to the static pressure in response to the change in the pressure, the dynamic pressure due to the rising air from the inlet 7 of the combustion gas or the like is inserted or removed. By using the combination of adjusting and controlling the influence of) and the suction pressure by the air blower, it is possible to adjust while satisfying the maintenance of the desired retention amount in the furnace as in the specific example described later.

Herein, the pressure at the outlet opening is set to be slightly static pressure, which is about 0 to +15 mm as a static pressure by a water column manometer, and is preferably +5 to 10 mm. A negative pressure causes intake of cold air outside, while a large positive pressure leads to blow out of the furnace, making stable operation of the furnace impossible.

Next, although the amount of retention is controlled, there is a difference in the time required for firing depending on the size of the particle size of the raw material, and the pressure of the outlet opening fluctuates according to the increase or decrease of the amount of retention. The amount of particles remaining in the furnace has a relationship as shown in the following equation between the area of the furnace and the pressure loss of the rising air in the layer in which the particles reside.

W = ΔP × A, where W is the amount of retention of the particles, ΔP is the pressure loss of the rising air in the layer in which the particles remain, and A is the cross-sectional area of the furnace.

In addition, since the particle falls backward to the rising air flow depends on the relationship between the particle size of the particle and the flow rate of the rising air flow, increasing the area space at the discharge opening reduces the flow rate of the rising air flow, thus reducing the particle size to some extent. In this case, even if the particle size is small, it is easy to drop and discharge without changing the amount of the air flow from the delivery cylinder 7 such as combustion gas. In the case of a large particle diameter, on the contrary, the area space of the discharge opening may be narrowed. Therefore, in order to increase or decrease the amount of retention while keeping the pressure of the outlet opening as a whole, the opening fan of the area control device 15 and the suction pressure of the blower, for example, the blower by opening and closing the damper 31 of FIG. By adjusting the suction force of (30), it becomes possible by adjusting (DELTA) P.

Here, the specific example of the furnace operation in the case of changing the particle size of a raw material by making rising airflows, such as combustion gas, constant in the airflow kiln in this technique using this invention is demonstrated.

Now, when the area control device 15 is fired at a relatively constant pressure for the raw material having a relatively large particle size and is opened at an opening suitable for the discharge of the fired material of the particle size, the particle size of the raw material has a small particle diameter. In the case of changing to, the fired material is less likely to be discharged, the above-mentioned ΔP increases, the amount of retention in the furnace is increased, and the pressure of the discharge opening increases. In this case, in order to properly adjust the positive pressure of the discharge opening, for example, by adjusting only the direction in which the damper 31 of FIG. 6 is opened to increase the suction force of the blower 30, the amount of retention is further increased (the above-mentioned agent). As described in the experimental results of FIG. 2, in general, the direction of reducing the internal pressure of the furnace, that is, the retention amount increases when the exhaust fan suction force is increased), and slagging (a fluidized bed in which the granules are well dispersed in the air stream (the mixed bed in the present invention) ) And floating up and down in the same state as the fixed layer of the apparent particle, causing the furnace to become unstable. As described above, in the case of the small particle size, it is appropriate to reduce the amount of retention (time). In this case, the inner cross-sectional area and the space of the position of the discharge opening 13 are enlarged by drawing out the area control device 15. Reducing the suction force of the blower 30 by adjusting the damper 31 of 6 degrees makes it possible to appropriately regulate the pressure of the outlet opening by adjusting the dampers 31 and to reduce the amount of retention so that the stabilization of the furnace state and smooth discharge of the plastics can be achieved. .

When the particle size of the raw material is changed from small to large, it becomes the opposite shape to the above and may perform the reverse operation. In addition, in the case of increasing or decreasing the amount of combustion gas and the like or the amount of the raw material, the pressure of the outlet opening increases. Also in this case, it is possible to cope by controlling the pressure of the discharge opening and the amount of retention in the furnace by the same operation as described above. Therefore, according to the present invention, the above-described control is possible, so that even if there are various conditions changes, (a) the pressure of the discharge opening and (b) the amount of residence in the furnace (pressure loss (ΔP) in the layer in which the particles stay) It is also possible to perform automatic control by interlocking detection and (c) adjustment of the damper to the desired ΔP and adjustment of the area adjusting device so that the pressure of the discharge opening becomes an appropriate value.

As described above, according to the present invention, (1) the pressure of the outlet opening is slightly reduced in response to various conditions such as the change in the amount of raw material feed, the change in the particle size of the fuel, the change in the amount of residence in the furnace, and the change in the amount of combustion gas, etc. (2) In addition to the change in the particle size and the feed rate of the raw material, the increase and decrease of the amount of retention can be adjusted. Since the flow rate of airflow can be added or subtracted, there is no need to change the input of combustion gas and the like.

Therefore, it is possible to stabilize the furnace state, such as maintaining an appropriate furnace temperature distribution and quantitative continuous discharge of the burned material.

On the other hand, in the general flow furnace, if the particle size of the raw material is changed, it is necessary to change the flow rate of the rising air in consideration of the minimum fluidization velocity (Umf) and the end velocity (Ut) of the particle diameter. The car becomes louder However, in the case of the air flow furnace using the present invention, it is not necessary to change the amount of combustion gas or the like to change the particle size to some extent, and can only cope by adjusting the cross-sectional area of the furnace at the position of the discharge opening and the opening and closing degree of the damper. There is an effect such as a small difference in the firing capacity, and the industrial value is large.

Claims (1)

Granular particle inlet and granular settling chamber installed in the upper part of the upright furnace of the ball tower structure, connected to the bottom of this settling chamber and connected to each other through the inverted conical shape, large diameter upright cylinder, small diameter upright cylinder, and small diameter In a continuous air flow kiln consisting of a firing material discharge cylinder installed through an inverted cone portion below an upright cylinder portion, and a plurality of raw material, air or combustion gas inlets provided in the small diameter upright cylinder portion and an inverted cone portion below it. And, through the junction of the fuel, air, or combustion gas inlet and the inverted conical section, the Haube plastics discharge opening of the inverted conical section is provided. A fired product in a continuous air flow kiln, characterized in that a cylindrical area control device which is slidable in an outer cylinder is provided for adjusting the volume. Pressure regulating device in the outlet opening.

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