JPH0743080A - Mantle draft controller - Google Patents

Abstract

PURPOSE:To stabilize the recovering condition of hot air into a kiln and a calcining furnace by a method wherein the value of mantle draft is inputted as the set value of a draft at the rear part of a bulkhead while the constant value control of the draft of rear part of bulkhead for a cooler is effected by a cooler exhaust fan damper. CONSTITUTION:When there is a difference between the actual value of a mantle draft and the set value of the same, the difference is inputted into a bulkhead rear part draft regulating meter 16 as the set value of a bulkhead rear part draft. The difference between the set value of a bulkhead rear part draft and the actual value of the same is operated by the bulkhead rear part draft regulating meter 16, into which the difference value of the result of operation of the mantle draft regulating meter 15 is inputted as a set value, and when the difference value is positive, the cooler exhaust fan damper 9 is operated in accordance with the value of difference. On the other hand, when the operating result of the regulating meter 15 is negative, the mantle draft control is effected by a control loop at the negative side of the value of difference. Thus, the fractuation of the mantle draft can be stabilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cement burning apparatus having a control means for keeping a constant amount of kiln combustion air in an air quenching cooler for cooling a high temperature clinker supplied from a rotary kiln.

[0002]

2. Description of the Related Art A high temperature clinker discharged from a kiln such as a rotary kiln needs to be cooled to a predetermined temperature, and an air quenching cooler (hereinafter abbreviated as a cooler) is usually used as this cooling device.

In such a cooler, the temperature of the cooling air that has been heat-exchanged with the high-temperature clinker is raised, and a part of it is recovered as combustion air for a kiln, a calciner, or waste heat boiler air. ， Excess air is discharged outside the cooler by the cooler exhaust fan.

In order to reduce the basic unit of heat quantity for burning the clinker, it is necessary to stabilize the recovered air at a temperature as high as possible and quantitatively. However, the clinker entering the cooler from the kiln has its amount, particle size and particle size. The distribution and temperature constantly fluctuate and stable collection of hot air is not possible.

Therefore, in order to prevent the unstable state, conventionally, the draft detector 13 of the mantle 17 at the clinker outlet of the kiln as shown in FIG. By changing the opening degree of the inlet damper 9 of 11, a control system for keeping the amount of hot air constant is configured.

The setting value of the draft controller 15 is the mantle 1
Although it is set lower than the atmospheric pressure in order to suppress the blowing of hot air from 7, the cooler exhaust fan 11 when the draft controller 15 has a deviation from the set value and the actual value is different.
The inlet damper 9 is opened and closed to control the draft in the mantle 17 to be constant.

[0007]

Such a general cooler control method has the following drawbacks. That is, the draft in the mantle 17 is constantly changing due to the dropout of the coating in the kiln, the rolling of raw materials, and the opening / closing of the cold air damper for controlling the hot air temperature for the boiler when using the waste heat boiler, and a deviation from the set value is generated. As a result, the cooler exhaust fan damper 9 opens and closes according to the deviation, so that the cooler exhaust amount constantly changes.

A change in the cooler exhaust causes a change in the amounts of the kiln combustion air and the calcination furnace combustion air, and this change naturally leads to a change in the combustion conditions of the kiln and the calcination furnace. It will change.

[0009]

[Means for solving the problem] In the current mantle draft control loop, a weir-shaped partition is provided on the upper part of the clinker layer that has fallen on the cooler plate, and the draft at the rear of the partition is detected.
This is a cascade control system in which the rear draft of the bulkhead is input, and the mantle draft value is input as the set value of the rear draft of the bulkhead, and the cooler exhaust fan damper performs the constant value control of the rear draft of the cooler bulkhead to achieve the above object. Is what you are trying to do.

[0010]

[Operation] By improving the controllability of the mantle draft, the state of hot air recovery to the kiln and calcination furnace became stable, which enabled a reduction in fuel consumption and stable operation of the cement firing process.

[0011]

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows an embodiment of a mantle draft control device according to the present invention. The control device of the present invention is provided with a weir-shaped partition wall 12 that opens onto the upper part of the clinker layer that has dropped onto the eyelet 2 of the cooler. The partition wall 12 functions to facilitate introduction of combustion air on the clinker layer of the cooler 18 into the kiln 1 and the calcining furnace (not shown). A draft detector 14 is provided on the downstream side of the partition wall 12 and in the vicinity thereof, and is connected to a conventional mantle draft control loop.

A specific example of control in the mantle draft control device of the present invention shown in FIG. 1 is shown in FIG. In FIG. 2, when the actual mantle draft value is different from the mantle draft setting value, the deviation is input to the partition rear draft controller 16 as the partition rear draft setting value. This controller 15 has a function of calculating the difference between the set value and the actual value and whether this difference is the positive side or the negative side of the set value, and the setting of the partition draft controller according to the variation amount. Entered as the value.

When the calculation result of the controller 15 has a positive deviation value, mantle draft control is carried out by the deviation side positive side control loop. That is, the partition rear draft controller 16 with the deviation value of the calculation result of the controller 15 as a new set value
The deviation between the partition rear draft setting value and the partition rear draft actual value is calculated by, and when the deviation amount is positive, the cooler exhaust fan damper 9 is opened according to the deviation amount. As a result, the mantle draft fluctuates to the negative side.
If the deviation is negative, the mantle draft control is performed by the negative deviation control loop. That is, the deviation between the partition rear draft setting value and the partition rear draft actual value is calculated by the partition rear draft control 16 using the deviation value of the calculation result of the controller as a new setting value, and when the deviation amount is negative, The cooler exhaust fan damper 9 is opened according to the deviation amount. As a result, the mantle draft moves to the positive side.

[0014]

By constructing such a control system according to the present invention, the drawbacks seen in the cement firing system due to the fluctuation of the mantle draft of the conventional apparatus shown in FIG. 3 are eliminated. That is, not only the fluctuation of the mantle draft is stabilized, but also the fluctuation of the used air volume when using the waste heat boiler or the drastic fluctuation of the draft due to the disturbance such as the fluctuation of the cooler layer thickness is suppressed. In addition, fluctuations in the cooler exhaust amount lead to changes in the kiln combustion air amount, which eliminates the drawback of deteriorating the combustion situation and ensures a stable kiln combustion air amount, which can stabilize the process. As a result, there is an advantage that it leads to a reduction in the basic unit of calorie calorific value.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of a mantle draft control device according to the present invention.

FIG. 2 is a flowchart for explaining the control of the present invention.

FIG. 3 is a schematic explanatory diagram of a conventional mantle draft control device.

[Explanation of symbols]

 1 Kiln 2 Cooler eye plate 3 Secondary air for burning kiln 5 Secondary air for burning calcination furnace 7 Cooler exhaust 9 Cooler exhaust fan damper 10 Waste heat boiler 11 Cooler exhaust fan 12 Partition wall 13 Mantle draft detector 14 Partition rear draft detection 15 Mantle Draft Controller 16 Rear Partition Draft Controller 17 Mantle 18 Cooler

Claims (1)

[Claims] 1. An upper part of a clinker layer is used for mantle draft control by a draft detector provided in a mantle for supplying high temperature air after heat exchange of a high temperature clinker with an air quenching cooler as combustion air to a rotary kiln. A weir-shaped partition is installed on the back of the partition, and a partition rear draft detector is installed on the downstream side of this partition to detect whether there is a positive or negative difference between the preset mantle draft setting value and the actual mantle draft value. , A mantle draft controller for selecting a positive or negative adaptive control loop is provided, and the mantle draft actual value is used as the partition rear draft setting value, and the partition rear draft is detected to detect the deviation between the partition rear draft setting value and the draft detection value. With a controller,
A mantle draft control device for stabilizing a mantle draft by providing means for opening and closing a cooler exhaust fan damper according to the deviation by the selection control loop.