JPH0542385B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a chute device for a cement clinker production furnace, and more specifically, the present invention relates to a chute device for a cement clinker production furnace, and more specifically, a chute for introducing granules into a chute for sending the granules from a granulation furnace to a firing furnace. The present invention relates to a chute device that can detect the presence or absence of blockage in holes and granule outlet holes, and can blow away stuck substances there. This is used in the field of technology to produce cement clinker by granulating or firing cement raw material powder.

[Conventional technology]

In cement clinker firing equipment, which consists of a granulation furnace that granulates cement raw material powder at high temperatures and a calcination furnace that sinteres the granules supplied from the granulation furnace at high temperatures, a spouted bed is formed in the granulation furnace. Along with being
There are some types in which a fluidized bed is formed in the kiln.

In these spouted beds and fluidized beds, if the temperature rises too much during granulation or firing, the semi-molten raw material powder, granules, etc. will further melt, and the viscosity of the raw materials will increase. As the viscosity increases, when agglomeration occurs, a phenomenon in which the raw material powder and granules exposed to high temperatures solidify and become lumps, the molten raw material powder and granules become stuck to the wall of the furnace. It adheres to things such as objects and becomes a fixed substance.

[Problem to be solved by the invention]

As mentioned above, the granules granulated in the granulation furnace fall from the granule introduction hole of the chute to the upstream chute, through the airtight discharge device to the downstream chute, and are fired from the granule outlet hole. sent to the furnace. At this time, since the falling movement of the granules themselves near the granule outlet hole is slow, the blockage of the granule outlet hole due to adhered substances can be cleared by the energy generated by the falling granules. It disappears. Note that the movement of the granules is slow in the vicinity of the granules introduction hole, and a similar situation occurs.

Therefore, once the granule introduction hole and granule outlet hole of the chute become clogged, it is necessary to manually remove the stuck substances, and the operation of the granulation furnace and firing furnace is stopped. The granule introduction hole or the granule outlet hole is brought into a conductive state by the operator breaking down the stuck material with a stick through the poking hole or the like.

This work is not easy and requires a great deal of effort and time to restart the furnace, and the continuous operation of these furnaces is impaired, resulting in a significant drop in clinker productivity.

The present invention was made in view of the above problems, and
Its purpose is to detect and eliminate blockages in the granule inlet and outlet holes of the chute, enable stable continuous operation of the cement clinker manufacturing furnace, and improve clinker productivity. It is an object of the present invention to provide a chute device for a cement clinker manufacturing furnace that can achieve the following.

[Means to solve the problem]

The present invention is applied to a cement clinker production furnace having a granulation furnace for granulating raw material powder and the like to produce cement clinker, and a fluidized bed type firing furnace for firing the granulated product.

Its characteristics are as shown in Figure 1.
The granulation furnace 2 and the calcination furnace 3 are arranged one above the other, and the lower part of the granulation furnace 2 and the upper part of the calcination furnace 3 are connected to the calcination furnace exhaust gas duct 12 that supplies the calcination furnace exhaust gas 7 to the granulation furnace 2. It is then connected. A chute 11 for discharging the granulated material from the granulation furnace 2 to the firing furnace 3 is configured to include an upstream chute 11A and a downstream chute 11B, and is provided to extend vertically. Between the upstream chute 11A and the downstream chute 11B, there is an inclined surface 22 forming an angle of repose formed by the accumulation of granules discharged from the granulation furnace 2. side chute 1
An airtight discharge means 21 is interposed to maintain airtightness between the air and the air. An upstream chute 11A and a downstream chute 11 are formed with the airtight discharge means 21 as a boundary.
The pressure fluctuation detection means 23 that detects the rise or fall of the static pressure at B and the pressure difference between the upstream chute 11A and the downstream chute 11B are set as the set differential pressure value △
A differential pressure detection means 25 is installed to detect when the pressure has become smaller than Pa. The pressure fluctuation detection means 2
3 and the differential pressure detection means 25, the upstream chute is directed toward the stuck objects 11a and 11b in the granule introduction hole 9A of the upstream chute 11A or the granule outlet hole 9B of the downstream chute 11B. A cooling medium jetting means 27 for spouting a cooling medium is provided in cooling medium introduction pipes 26A and 26B attached to each of the downstream chute 11A and the downstream chute 11B.

〔Effect of the invention〕

According to the present invention, when the granule introduction hole and the granule outlet hole become blocked due to solid matter, this is detected by the signals from the pressure fluctuation detection means and the differential pressure detection means, and the coolant jetting means is activated. As a result, the stuck material is automatically blown away. As a result, blockage in the granule introduction hole and granule outlet hole is prevented, and stoppage of the cement clinker production furnace is avoided.
The effort and time required for recovery can be saved. Therefore, stable continuous operation is ensured in the granulation furnace and firing furnace, and the productivity of cement clinker is significantly improved.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The chute device of the present invention will be explained in detail below based on an example of a cement clinker firing device in which the chute device is employed.

The cement clinker firing device 1 shown in FIG.
It is composed of cement clinker production furnaces 20 such as a granulation furnace 2 and a firing furnace 3 arranged above and below, and other equipment not shown.

The granulation furnace 2 is a furnace for granulating cement raw material powder, and is provided independently from the firing furnace 3 for firing the granulated material in order to facilitate operations to enhance the granulation effect in the furnace. It is being This granulation furnace 2 is a spouted bed furnace that introduces firing furnace exhaust gas to form a spouted bed 4A, which is the furnace inner layer 4, and is composed of a body portion 2A and an inverted conical portion 2B formed below the body portion 2A. Note that this granulation furnace 2 is not limited to one having the spouted bed 4A, but may be one having a fluidized bed, and in short, any furnace may be used as long as it forms an inner layer.

A raw material powder inlet 5 for introducing cement raw material powder is opened at the lower part of the above-mentioned inverted conical part 2B, and an appropriate number of burners 6 for heating the material to be granulated are installed near the raw material inlet 5. has been done. An exhaust gas inlet 8 is opened at the lower end of the inverted conical portion 2B to introduce the firing furnace exhaust gas 7 which serves as combustion air for the burner 6 and forms the spouted bed 4A.

In addition, the inverted conical part 2 above the raw material powder inlet 5
A granule introduction hole 9A is opened in the side portion of the body portion 2A for introducing the granule, whose particles have grown by circulating in the spouted bed 4A, into the firing furnace 3. Furthermore, an exhaust gas outlet pipe 1 is provided at the upper end of the granulation furnace 2 to discharge the exhaust gas that has passed through it.
0 is connected, and the exhaust gas is led out to a raw material powder preheating section (not shown).

The firing furnace 3 stores the granules in a fluidized bed 4B, which is the furnace inner layer 4.
The firing furnace 3 is provided with a chute 11 that supplies the granules discharged from the granulate introduction hole 9A of the granulation furnace 2 to the fluidized bed 4B. A firing furnace exhaust gas duct 12 extending vertically is connected to send the firing furnace exhaust gas 7 to the exhaust gas inlet 8 of the granulation furnace 2 .

Further, an air distribution plate 13 is provided at the bottom of the firing furnace 3, and an air introduction pipe 14 for introducing fluidizing air into a wind box formed at the bottom of the firing furnace 3 is connected to the air distribution plate 13. There is. Furthermore, fluidized bed 4
A fuel supply pipe 15 for supplying fuel such as pulverized coal is attached to B, and a transfer pipe 16 for sending the fired granules to a cooler (not shown) is provided.

To explain the above-mentioned chute 11, the chute 11 is composed of an upstream chute 11A and a downstream chute 11B, and extends vertically. An airtight discharge means 21 is interposed between the upstream chute 11A and the downstream chute 11B, and the upstream chute 11A is connected to the upper opening of the airtight discharge means 21.
A downstream chute 11B is connected to the lower opening.

Such an airtight discharge means 21 causes the granules in the spouted bed 4A of the granulation furnace 2 to fall from the granule introduction hole 9A to the upstream chute 11A, and forms an inclined surface based on the angle of repose within the airtight discharge means 21. 22 so that the granules can be deposited once.

That is, by depositing the granulated material discharged from the granulation furnace 2 between the upstream chute 11A and the downstream chute 11B, airtightness between the upstream chute 11A and the downstream chute 11B is achieved. is maintained, preventing the firing furnace exhaust gas from bypassing to the granulating furnace 2 through the chute 11, and discharging the granulated material while collapsing the inclined surface 22.

For this purpose, a conduit 21a is provided on the lower surface of the airtight discharge means 21 for spouting a cooling medium (for example, air). The granules fall down the downstream chute 11B and enter the granule outlet hole 9.
B and is mixed into the granulated material being fired in the fluidized bed 4B.

Upstream chute 11A and downstream chute 11B
are provided with pressure gauges 23A and 23B that constitute a part of the pressure fluctuation detection means 23, and detecting portions 24A and 24B are installed so that the static pressure within the respective chutes 11A and 11B is measured. It is opened.

Incidentally, when the cement clinker production furnace 20 is operated normally, the pressure in the space above the spouted bed 4A becomes almost atmospheric pressure because the granulation furnace 2 is connected to the raw material powder preheating section, and the firing Since fluidizing air is introduced into the furnace 3, the pressure within the fluidized bed 4B is maintained at a predetermined level of positive pressure.

In addition to the pressure fluctuation detection means 23 described above, a differential pressure detection means 25 detects the pressure difference between the upstream chute 11A and the downstream chute 11B, and detects that the differential pressure has become smaller than the set differential pressure value ΔPa. are installed and connected to the above-mentioned detection units 24A and 24B, respectively.

Further, cooling medium introduction pipes 26A and 26B are attached to the upstream chute 11A and the downstream chute 11B in the vicinity of the detection parts 24A and 24B, respectively, and the cooling medium introduction pipes 26A and 26B have cooling medium jets. Control valve 27 constituting means 27
A, 27B and their conduits 27a, 27b are connected. Note that the control valves 27A and 27B are operated to open in response to a blockage release command signal, which will be described later.

The above-mentioned cooling medium introduction pipes 26A and 26B are directed to the granule introduction hole 9A and the granule outlet hole 9B, and due to the occurrence of agglomeration, the granule introduction hole 9A or the granule outlet hole When the block 9B becomes blocked, the coolant jetting means 27 can blow away the stuck objects 11a and 11b.

According to such an embodiment, the stuck substances 11a or 11b in the granule introduction hole 9A of the upstream chute 11A and the granule outlet hole 9B of the downstream chute 11B can be removed as described below. I can do it.

First, the manufacturing process of cement clinker will be briefly described. As shown in FIG. 1, cement raw material powder is introduced into the lower part of the spouted bed 4A from the raw material powder inlet 5 opened at the lower part of the granulating furnace 2. The firing furnace exhaust gas 7 from the firing furnace 3 is supplied to this portion, and the fuel ejected from the burner 6 is combusted. As a result, the material to be granulated is rapidly heated and becomes a semi-molten state, and a spouted bed 4A is formed by the energy of the combustion gas and the firing furnace exhaust gas 7.

The granules that have grown to a predetermined size through circulation movement are transported through the granules introduction hole 9A and the airtight discharge means 21.
The granulated material is then supplied to the firing furnace 3 through the granulated material outlet hole 9B. At this time, the inclined surface 22 is broken by the cooling medium ejected in pulses from the conduit 21a, and the granules fall down the downstream chute 11B and enter the firing furnace 3 through the granule outlet hole 9B. It is sent and mixed into the granulated material being fired.

Powdered coal and the like are supplied from a fuel supply pipe 15 connected to a fuel supply device (not shown). The temperature inside the kiln 3 is maintained at a high temperature of 1350 to 1450°C, and cement clinker is manufactured. The clinker is in the transfer pipe 16
is sent to the cooler via.

Next, the detection of a blocked state in the granule introduction hole 9A and the granule outlet hole 9B and the operation for resolving the same will be described with reference to the flowchart shown in FIG. 2.

When the cement clinker firing apparatus 1 enters steady operation, the pressure fluctuation detection means 23 including the pressure gauges 23A and 23B, the differential pressure detection means 25, and the coolant jetting means 27 are placed in a measurement or operating state.

In the case of the pressure fluctuation detection means 23, the pressure gauge 23
A and 23B measure the static pressure of the upstream chute 11A and the downstream chute 11B. At the same time, the differential pressure detection means 25 measures the differential pressure ΔP between the upstream chute 11A and the downstream chute 11B, and determines whether the differential pressure ΔP is equal to or smaller than the set differential pressure value ΔPa. (Step 1 of the flowchart, hereinafter referred to as S1, etc.).

In addition, during normal operation, the upstream chute 11A
As long as the static pressure inside the downstream chute 11B is lower than the static pressure inside the downstream chute 11B and the upper part of the airtight discharge means 21 is filled with granules, a certain pressure difference will be generated between the two sensing parts 24A and 24B. , it is almost maintained.

Therefore, if there is a blockage in the granule introduction hole 9A or the granule outlet hole 9B, the pressure inside the chute 11 is equalized and ΔP becomes equal to or less than ΔPa.
In such a case, the pressure change detection means 23 determines whether the static pressure of the upstream chute 11A is higher than the normal value using the pressure increase determination device 23C (S2). If the pressure is above a normal value, it means that it is affected by the pressure of the firing furnace 3.

That is, this effect occurs because the granulated material introduction hole 9A is in a closed state and the inside of the upstream chute 11A is not communicating with the granulation furnace 2. Therefore, a blockage release command signal for the granule introduction hole 9A is output, the control valve 27A is opened, and the cooling medium from the cooling medium tank (not shown) is spouted toward the granule introduction hole 9A. Fixed object 11a
is blown away (S4).

The stuck material 11a is blown away and the granulated material introduction hole 9
When the blockage condition at A is eliminated, the differential pressure ΔP becomes larger than the set value ΔPa (S6), and the jetting of the cooling medium is automatically stopped (S7). For example, if a timer 28A is installed upstream of the control valve 27A, the blow-off operation can be maintained for a certain period of time, which has the advantage of preventing frequent intermittent control operations.

If the above-mentioned granule introduction hole 9A is not clogged, in step 3 it is determined whether or not the granule outlet hole 9B is clogged. That is, in the pressure fluctuation detection means 23, the downstream chute 11B
The pressure drop determination device 23D determines whether the static pressure is lower than a normal value, that is, a certain positive pressure (S3). If the pressure is below the normal value, the granule outlet hole 9B
A blockage release command signal is output for control valve 2.
7B is opened and the cooling medium is ejected toward the granule outlet hole 9B, and the stuck material 11b is blown away (S5).

The stuck material 11b is blown away and the granulated material outlet hole 9
When the blockage condition at B is eliminated, the differential pressure ΔP becomes larger than the set value ΔPa (S8), and the jetting of the cooling medium is automatically stopped (S9).

As can be seen from the above detailed explanation, there is a pressure fluctuation detection means that detects an increase or decrease in static pressure in the upstream chute and the downstream chute, and a pressure fluctuation detection means that detects a rise or fall in static pressure in the upstream chute and the downstream chute. We installed a differential pressure detection means to detect this, and a coolant jetting means that can enter operation upon receiving signals from both of the above means. It is possible to determine whether a blockage has occurred, and a blow-off operation is automatically performed as necessary.

As a result, clogging of the granule inlet hole and the granule outlet hole is prevented, the shutdown of the production furnace is avoided, and the effort and time required for its recovery are saved. In granulation furnaces and calcining furnaces, stable continuous operation is ensured and cement clinker productivity is significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a control system diagram of an embodiment of a cement clinker firing apparatus employing the chute device of the present invention, and FIG. 2 is a flowchart showing the procedure for removing blockages in the chute. 2... Granulation furnace, 3... Calcining furnace, 7... Calcining furnace exhaust gas, 9A... Granule introduction hole, 9B... Granule outlet hole, 11... Chute, 11A... Upstream chute, 11B...Downstream chute, 11a, 11
b... Fixed matter, 12... Firing furnace exhaust gas duct, 2
0... Cement clinker production furnace, 21... Airtight discharge means, 22... Inclined surface, 23... Pressure fluctuation detection means, 25... Differential pressure detection means, 26A, 26B...
...Cooling medium introduction pipe, 27...Cooling medium jetting means,
△Pa...Setting differential pressure value.

Claims (1)

[Scope of Claims] 1. A cement clinker manufacturing furnace having a granulation furnace for granulating raw material powder etc. to produce cement clinker, and a fluidized bed type firing furnace for firing the granulated product, comprising: The granulation furnace and the calcination furnace are arranged one above the other, and the lower part of the granulation furnace and the upper part of the calcination furnace are connected by a calcination furnace exhaust gas duct that supplies the calcination furnace exhaust gas to the granulation furnace. A chute for discharging the granulated material from the furnace to the firing furnace is provided to extend vertically and is composed of an upstream chute and a downstream chute, and the granulated material is disposed between the upstream chute and the downstream chute. An airtight discharge means is interposed to maintain airtightness between the upstream chute and the downstream chute, even on an inclined surface forming an angle of repose formed by accumulation of granules discharged from the furnace, and the airtightness is maintained between the upstream chute and the downstream chute. Pressure fluctuation detection means detects an increase or decrease in static pressure between an upstream chute and a downstream chute that are formed with the discharge means as a boundary; A differential pressure detection means is installed to detect the change in pressure, and upon receiving the signals from the pressure fluctuation detection means and the differential pressure detection means, the granule introduction hole of the upstream chute or the granule outlet hole of the downstream chute is installed. cooling medium introduction pipes attached to each of the upstream chute and the downstream chute toward the fixed object,
A shoot device for a cement clinker manufacturing furnace, characterized in that a cooling medium jetting means for jetting out a cooling medium is provided.