JPS5984078A - Pressure regulator for opening section of discharge for baked material in continuous air-current baking furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure regulating device for an outlet opening for a fired product in a continuous air flow firing furnace having a vertical column structure for firing powder and granular materials. The inventors of the present invention have previously
7-1000 and JP-A-57-28982 proposed a continuous air flow firing furnace with a vertical cavity structure and an air flow firing method using this furnace, but this technology (
(hereinafter referred to as technology), the relationship between the feed port of the raw material, the particle size of the raw material, the retention meter in the furnace, etc. is restricted to a specific range.
Therefore, it was difficult to stabilize the furnace condition in response to wide changes in IJ conditions.

The outline of this technology proposed earlier will be explained based on FIG. ) is sent from the inlet parts 7 and 6a to 6d to form a fired layer due to the rising air current, and the fired product is transferred to the inverted conical part 10b.
This furnace has a structure in which exhaust gas is discharged from the exhaust pipe 8 and combustion exhaust gas is discharged from the exhaust pipe 2.

The unique feature is that the upper part of the furnace is equipped with a sedimentation chamber with a slow flow rate of updraft to prevent raw materials or fired products from scattering together with the combustion exhaust gas, and then a mixed layer of updraft and powder particles. (In this technology, -Ct, 1- refers to a layer in which powder and granules are suspended by an updraft, an fM ring, and a fluidized layer)
The powder is fired while remaining in the furnace for a certain period of time and then falling for a while. At this time, in the mixed layer 4 (large diameter straight cylindrical portion 9a), the flow velocity of the rising air current is small, and the mixed layer 5 (
Since the flow velocity is high in the small-diameter straight cylinder portion 9b), as a result, a dense mixed layer with a high concentration of powder and granules is formed in the mixed layer 4, and a dilute mixed layer is formed in the mixed layer 5. do.

Since the furnace has such a structure, it is possible to fire the mixed layer 5 in the highest temperature range, and a temperature difference is created between the mixed layers 5 and 4, resulting in high thermal efficiency. '-1,
Another feature is that it is continuously fed into the furnace! Because there is a settling chamber in the upper part of the furnace, the granular raw materials are rarely discharged from the second part of the furnace, and the raw materials and fired products that remain in the furnace are suspended by the pressure of the rising air. It continues further.
The amount of raw material that is unbalanced by the supply of raw materials falls for a while, and instead of being deposited on the bottom of the furnace, it is released and discharged directly outside the furnace while floating and rolling. As mentioned above, in this technology, the LL and υ1 output of the fired product do not overflow and discharge like in a general fluidized bed furnace, and the
Because the technology does not involve dumping and discharging the fired products in a device directly connected to the bottom of the furnace, as in Publication No. 1093, etc., the technology directly discharges the fired products from the furnace to the outside of the furnace.
1) The pressure of the rising airflow blowing up the lower combustion gas etc. from the feed tube 7 supports the desired heavy use of the powder and granules floating and staying in the furnace (
As will be explained later, this corresponds to the pressure loss in the furnace) and the discharge and opening of the fired products [balanced at a pressure (static pressure) near atmospheric pressure in one part] Discharging and the temperature of the firing zone of the mixed layer 5 near the discharge port 'f
: In order to maintain the maximum temperature, etc., it is necessary to keep the pressure at the 4:11 outlet opening close to atmospheric pressure and slightly positive.

This condition can also be achieved in the technology of the prior application shown in Fig. 1 by optimizing the position of the discharge opening 1-1 and the operating method, but by changing the particle size and/or feeding amount of the raw material. In this case, the amount of granular material retained in the furnace increases or decreases, and the pressure loss of the rising air changes.

Since the pressure at the discharge opening changes with the temperature and the temperature changes, and the stable region shifts, a device rf for adjusting the pressure at the discharge opening and the amount retained in the furnace is required, which can respond to these changes in conditions. In order to solve the problems of ft et al., the present inventors investigated the discharge mechanism of the fired product in this technology, the position of the discharge opening, the change in the amount of powder and granules retained in the furnace, the change in the raw material particle size, and the discharge opening. We have conducted various studies on the interrelationships of pressure, etc., and the results will be explained below. 1. As shown in FIG. 2, the discharge tube 8 is connected to the inlet tube 7 for combustion gas, etc. and the inverted conical portion 10b.
If the joint 12 is provided in two parts, the pressure in the first part of the publication opening becomes negative pressure. Unless the suction pressure of the combustion gas is reduced by an exhaust fan (not shown) to make it a positive pressure, the desired amount of retention in the furnace cannot be maintained. Normally, the pressure is negative, so the air flow rate inside the furnace increases due to the intake of cold outside air, which cools the mixed layer 5 and makes it difficult to maintain the maximum temperature, causing changes in the temperature distribution inside the furnace and stagnation. Maintaining the amount at a certain point (?4 lT!) does not provide stable operating conditions in the fields.

The case shown in FIG. 3 is a case in which one part of the exhaust pipe 8 is provided in the inlet pipe 7 for combustion gas, etc., located below the joint 12. In this case, since the flow velocity of the upward current of combustion gas or the like in the feed tube 7 is higher than the final velocity of the powder, the fired product does not fall and be discharged.

Therefore, the fired product floats and accumulates around the lower part of the inverted circular ζ1F-shaped part job, but when it exceeds the -travel, it cannot be supported by the upper airflow from the inlet pipe 7 of combustion gas, etc., and is discharged [
] When the positive pressure becomes large, the fired product falls pulsatingly with the airflow and is discharged from the publication cylinder 8.

Therefore, quantitative and continuous discharge is not possible and the furnace condition is not stable. In the case of Fig. 4, the position of the discharge tube 8 is provided through the joint 12, but in this case, it is possible to maintain the desired retention amount. It is possible to maintain an appropriate temperature distribution in the furnace and to make the pressure at the discharge opening slightly positive, and quantitative and continuous discharge is also possible. However, the operating range as an industrial furnace is narrow. For example, if the particle size of the raw material changes from large to small, the retention 1B in the furnace will increase and the pressure in the extraction interval 11 will also increase, so the pressure in the discharge volume [] part mentioned above should be slightly positive. It is not possible to satisfy the conditions set forth below. Furthermore, if the particle size changes in the opposite manner, the opposite result will result, making it difficult to operate the furnace stably in response to changes in the particle size of the raw material.

Therefore, the present inventors examined the experimental results etc.81' (y7
j As a result, the airflow firing furnace in this technology has a joint part 12i
Through the reverse circle C11: At the bottom of the shape part tab is the firing material 1
By providing 11 openings and adjusting the area and space of the openings, (1) it becomes easy to make the pressure at the discharge opening slightly positive, and 0) the particle size of the raw material changes, etc. It has been found that it is possible to operate the reactor stably by adjusting the pressure of 1 part of the discharge amount or increasing or decreasing the retention amount in response to changes in the conditions.

The present invention v: is based on the findings of J. Kori et al., and includes a powder inlet provided at the upper part of a vertical furnace having a hollow column structure, a sedimentation chamber for the powder, and a connection below the sedimentation chamber. a large-diameter straight cylinder part and a small-diameter straight cylinder part connected to each other via an inverted conical part, a fired product discharge tube provided through the inverted conical part below the small-diameter straight cylinder part, and the small-diameter straight cylinder part and its lower part. In a continuous air firing furnace consisting of a plurality of inlet ports for combustion gas, etc. provided in an inverted cone-shaped part, the combustion gas, etc. is injected into the inverted cone via a joint part 12 between the inlet cylinder 7 and the inverted cone-shaped part tab. A continuous air flow firing furnace characterized in that a fired product discharge opening 13 is provided at the lower part of the shaped portion tab, and a fired product discharge tube 8 and an area adjustment device 15 for internuclear space C1ffl are provided in the fired product discharge opening 13. This is a pressure slope device for the discharge opening of the fired product.

The configuration of the present invention will be explained below along with its operation based on examples.

FIG. 5 is an example of implementing the present invention. The inverted conical portion 10b below the small diameter iα cylinder portion 9b and the inlet cylinder 7 for combustion gas, etc.
A fired product discharge volume 11 part 13 is provided at the lower part of the inverted conical part 101 via the joint part 12 of the opening, and a fired product discharge pipe 8 is provided in this opening.

In the figure, 17 is a lid that can be freely opened and closed for discharging the fired product provided at the tip of the outlet, and 18 is the fired product that is discharged. Then, the first part 3 is provided with an opening area adjusting device 15 which can be slid inside the outer cylinder 14.

This area measuring device I5 has a hole at its tip, and the static pressure at the opening 1'' can be measured using the pressure detection tube 16.

As mentioned above, in proper operation of this airflow kiln,
It is necessary to adjust the pressure at the discharge opening and the retention amount u1 in the furnace in response to occasional changes in conditions, and the adjustment using the present invention will be described below.

In other words, in this air flow firing furnace, the pressure in the discharge volume Li section is determined by the positional relationship between the combustion gas etc. feed tube 7 and the fired product discharge volume 1-1 section 13, and the discharge volume 1 volume is By providing a section, it is easy to make the pressure of JJ1 release [1 section] slightly positive. and!
To adjust the pressure of the discharge amount [-1 part to a slightly positive pressure in response to the increase or decrease in the pressure, t,1, the area adjustment device 15
By adjusting the influence of dynamic pressure due to the rising airflow from the inlet tube 7 of combustion gas etc. by taking in and out of the combustion gas, and by adjusting the suction pressure by the exhaust fan, as in the specific example described later, It is possible to adjust the retention amount while maintaining the desired retention amount.

Here, the pressure of 1-1 part of the Jll opening is 0 to 1-1 as the static pressure due to the water column pressure to be slightly positive.
Approximately 15 mm, preferably υ15~lO+nm
It is. When the pressure is set to negative, cold outside air is sucked in, and when the positive pressure is set to high, airflow inside the furnace is blown out, making stable furnace operation impossible.

Next, regarding the adjustment of the retention amount, there is generally a difference in IHI when firing is essential depending on the particle size of the raw material, and the pressure at 1" part of the discharge volume fluctuates depending on the increase or decrease in the retention amount, so the retention amount ( time) will need to be adjusted. The M in which the particles stay in the furnace has the following relationship between the cross-sectional area of the furnace in the layer where the particles stay and the pressure loss of the upper airflow.

W=APXA, where W is the amount of powder retention, ΔI) &
J is the pressure loss of the updraft in the layer where particles stay, and 8 is the cross-sectional view of the furnace. Furthermore, for a particle to fall against the upper airflow, it depends on the relationship between the particle size of the particle and the flow velocity of the ascending airflow. Therefore, if the area space at the discharge opening is widened, the flow velocity of the upper airflow will be reduced. Even small particles can be easily discharged without changing the amount of IJ+.If the particles are large in size, the opposite is true, and the area space of the discharge opening can be narrowed f'L.

Therefore, in order to increase or decrease the stagnation 14 while keeping the pressure of the discharge amount [1 part] constant, the 01 function can be adjusted by adjusting the opening of the area adjustment device 15 and the suction pressure of the exhaust fan. It becomes.

Here, a specific example of the operation of the airflow firing furnace according to this technology using the present invention will be described in the case where the particle size of the raw material changes while keeping the rising air flow of combustion gas etc. constant.

Currently, the area adjustment device 15 is used for relatively large particle size raw materials.
f: The pressure at the discharge opening becomes slightly positive and the opening IB4 is suitable for discharging the fired product of that particle size. In the case where the fired product becomes difficult to discharge, the above-mentioned ΔP increases, the retention of particles in the furnace 11: increases, and the pressure at the discharge opening increases. In this case, adjust only the suction pressure by the exhaust fan while keeping the positive pressure of the discharge amount of 11 parts at an appropriate level.
If the particle size is small, it is appropriate to reduce the retention amount (time), so in this case, area adjustment is necessary. By adjusting both the withdrawal of the device and the reduction of the exhaust air pressure, the pressure at the discharge opening can be made appropriate and the amount of retention can be reduced, thereby stabilizing the furnace condition and smoothing the discharge of the fired product.

When the particle size of the raw material is changed from small to large, the opposite phenomenon occurs and the operation can be performed in the opposite manner. The pressure at the discharge opening also increases or decreases when the amount of broken combustion gas or the like or the amount of raw materials increases or decreases. In this case as well, Jut is
Deka+:++'? This can be dealt with by adjusting the pressure of B and the amount of retention in the furnace. According to the present invention, the above-mentioned control is possible, so (a) the pressure of 1-1 part of the discharge amount, (b) the retention blow in the furnace (pressure loss in the layer where particles stay), and (c) It is also possible to automatically control by detecting the suction pressure of the exhaust fan and setting the position of the -C area adjustment device 15 and the pressure range of the output opening 1-1 based on the mutual relationship.

As described above, according to the present invention, (1) the pressure at the discharge opening can be adjusted to a slightly positive pressure in response to various changes in conditions;
(2) Particle size change of raw material, 3) 1.
It is possible to increase or decrease the retention amount in response to changes in i, and to adjust the flow velocity of the upper row airflow at the discharge opening simply by adjusting the opening of the eye-area adjusting device 15 in response to a certain change in particle size. Since the amount can be adjusted, there is no need to change the purpose of feeding combustion gas, etc.

Therefore, it is necessary to maintain an appropriate temperature distribution in the furnace and to maintain the stability of the fired product.
It is possible to stabilize the furnace conditions such as continuous discharge. In this regard, in the general flow 11+ furnace v;1,
The particle size of the raw material is changed'i1. Minimum fluidization velocity of tobacco particles (
It is necessary to change the flow velocity of the upper row airflow in consideration of Umf ) and terminal velocity (old), and the difference in firing ability increases depending on the particle size. However, in the case of the airflow kiln using the present invention, the amount of t;L emissions [
Since this can be achieved by only partially adjusting the opening and adjusting the suction pressure, it has the effect of reducing the difference in firing ability depending on the particle size, and has great industrial value.

[Brief explanation of the drawing]

FIG. 1 schematically shows a vertical airflow firing furnace using the apparatus of the present invention. zo fL
FIG. 5 is a vertical cross-sectional view schematically showing the fired product discharge amount of 11 parts, the extraction tube, and the area adjustment device for the 1'' portion between the cores of the present invention. 2... Combustion gas discharge 1'' 3... Powder feed ['1 68~6d... Side wall combustion gas etc. feed 1'' 7... Lower combustion gas etc. feed cylinder 8... Firing Material discharge tube 9a...Large diameter straight cylinder part 9b.
・・Small diameter straight cylindrical portion 101) ・・Reverse elevation shape portion 11
...Sedimentation chamber 12...Joint section 13...Fired product discharge amount [] section 15...Opening area adjustment device 16...Opening pressure detection tube 18...Fired product output unit Patent Attorney fno1 Hisashi Fujitake”jj, 5f
'2nd tII';, 'i', 4 Figure 3 Figure 511 18~2°i

Claims (1)

[Claims] A powder inlet and a settling chamber for powder and granular material provided at the upper part of a vertical furnace with a hollow tower structure, and a large diameter straight cylinder part connected to the bottom of the settling chamber and continuous to each other via an inverted conical part. A small diameter straight cylindrical part, a fired product discharge pipe installed through an inverted conical part below the small diameter straight cylindrical part, and a plurality of fuel, air vents or Combustion gas supply "1. In a continuous air firing furnace, the fuel, air neck or combustion gas delivery cylinder is passed through the joint between the inverted conical part and the inverted conical part to discharge the fired product. [1] A fired product 411 opening in a continuous air flow firing furnace characterized by a fired product discharge pipe and a surface bond adjustment device f: provided in the opening part in the fired product discharge interval [1]
pressure regulating device.