JPS6348818B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a clinker temperature control method that always maintains the discharged clinker temperature at a specified value in a clinker quenching machine that cools high-temperature baked ingots discharged from a rotary kiln.

In a clinker cooling system, high-temperature clinker discharged from a rotary kiln is conveyed by an oscillating cage-like conveyor, and air is blown from below the conveyor to rapidly cool it down. It is used as secondary air and the rest is released into the atmosphere as exhaust air.

However, in this clinker firing equipment, it is desirable that the temperature of the clinker itself discharged from the clinker quenching machine is cooled to a specified value, but it is very difficult to detect the temperature of the clinker itself, that is, the temperature of the baked ingot. Moreover, since the amount of clinker discharged from the rotary kiln constantly fluctuates, it has been considered inevitable that the temperature of the discharged ingot also fluctuates to some extent.

In other words, if we explain the fluctuation in the amount of clinker discharged in detail using Fig. 2, the amount of clinker discharged from the rotary kiln at the beginning of operation of the rotary kiln is almost constant, so it changes linearly as shown in Fig. 2. However, after the rotary kiln has been operated for a considerable period of time, a deposit layer of baked clinker lumps called a coating forms on the inner wall of the rotary kiln, and the growth of this coating blocks the clinker that is scheduled to be discharged one after another. This causes the rotary kiln to stagnate inside the rotary kiln.

Therefore, since there is an amount of clinker blocked by this coating, the amount of clinker discharged decreases, and the discharge amount changes from a linear discharge amount to a discharge amount that gradually follows a downward line.

However, if this coating grows sequentially like a bamboo shoot, it will sometimes be destroyed by the impact of the clinker, and at the point when this coating is destroyed, the discharge amount, which has followed a downward line as shown in the figure, will be blocked. Since the clinker that has been blocked is discharged all at once, the amount increases rapidly.

This rapidly rising discharge rate is affected by the amount of clinker that has been blocked, and thereafter the amount of clinker gradually recovers to the state at the beginning of operation.

As detailed above, the amount of clinker discharged from the rotary kiln to the clinker quenching machine is always around the average value, and the period during which it is discharged is limited to the initial period of operation of the rotary kiln. Because the wave-like phenomenon of rapid decreases repeats, emissions near the average value are rare. Therefore, the temperature of the baked ingot at the outlet of the clinker quenching machine constantly fluctuates due to the amount of clinker that frequently increases and decreases.Also, it is very difficult to detect the temperature of the baked ingot of the clinker itself, so the quenching machine One of the challenges of clinker quenching equipment is to cool the baked ingot temperature at the outlet to a specified value.

Therefore, such fluctuations in the temperature of the baked ingots require the clinker quenching machine itself to be larger, or have an adverse effect on the clinker quenching machine and auxiliary equipment, such as burning out the transport conveyor or reducing the efficiency of crushing equipment. It is something.

An object of the present invention is to provide a clinker quenching machine capable of cooling the constantly fluctuating clinker sintered ingot temperature to a specified value even at the outlet of the clinker quenching machine without lowering the temperature of the recovered air. It is.

In short, this invention is a method for cooling high-temperature clinker supplied from a rotary kiln to a specified value using an oscillating grate quenching machine. This is a clinker temperature control method in which the damper control signal is used to control the discharged clinker temperature by controlling the damper installed in the cooling air supply pipe of the cooling room in the cooling range beyond the heat recovery secondary air range with a time lag. Features.

The present invention will be explained below with reference to the drawings. In Fig. 1, 1 is a rotary kiln, 2 is a clinker firing burner, 3 is a combustion chamber, and 4 is an induction fan installed at the raw material supply end side of the rotary kiln 1, which constantly draws air inside the kiln through an induction pipe 5. There is. 6
The clinker quenching machine is surrounded by a refractory furnace material and is disposed below the clinker drop port 7.

Reference numeral 8 designates the oscillating conveyor in the form of a cage, 9 a driving device for the conveyor 8, and 10 a clinker discharge port. A part of the air that has cooled the clinker is used as secondary air, and most of the remaining air is exhausted by an exhaust fan 11 from an exhaust port 12 through an exhaust pipe 13. Reference numeral 14 is a partition plate provided on the furnace wall above the conveyor, which partitions the quenching machine 6 into furnace chambers 15 and 16. Furnace room 1
At the bottom of the conveyor on the 5th side, air for clinker cooling is placed in a cooling air chamber (first cooling air chamber on the kiln side) 17,1.
8 are divided. Of these, 17 are air chambers for detecting the thickness of the clinker layer, and 18 are chambers for feeding air that is used as secondary air for the burner 2 after cooling the clinker. The high temperature upstream side from the position on the grate corresponding to the partition plate 14, that is, the portion of the cooling air chambers 17 and 18 (in the drawing) becomes the heat recovery secondary air range. Cooling air chambers 19 and 20 are defined at the bottom of the conveyor on the furnace chamber 16 side (cooling range). Each air chamber 17, 18, 19, 20 is provided with a blower pipe 25, 2 by a blower 21, 22, 23, 24.
Air is sent in via 6, 27, 28. Clinker at 1300 to 1400°C, which is heated and fired by burner 2 while descending in kiln 1, is sent to fall port 7.
It falls onto the conveyor 8 of the quencher 6 and is conveyed toward the outlet 10 of the cooler.

Air for cooling the clinker is blown upward from the bottom of the conveyor 8, and the air passes through the clinker layer to cool the clinker, and the clinker is discharged at the discharge port 10 at a temperature of approximately 100°C. .

A part of the air that has become high temperature through heat exchange with the clinker is used as secondary air for the burner 2, and the rest is exhausted from the exhaust port 12 by the exhaust fan 11.

29 is a pressure detector that detects the pressure in the cooling air chamber 17, and the pressure change becomes a signal that determines the target value of the controller 31 via the signal converter 30, while the signal from the signal converter 30 is used for time lag calculation. Vessel 32
This becomes a signal that determines the target value of the controller 33 via the . 34 is a limiter for keeping the signal from the controller 33 within an appropriate range, and 35 is a damper that is automatically operated by the signal.

The above is a general explanation of the structure and clinker quenching machine of the present invention, but in the conventional clinker quenching machine, as mentioned above, the amount of clinker discharged from the rotary kiln always changes, and the temperature of the baked ingot also changes accordingly. In order to deal with this, the present invention takes the following steps.

That is, since the pressure in the cooling air chamber 17 changes due to changes in ventilation resistance when air passes through the clinker layer and cools it, that is, changes in the thickness of the clinker layer, this pressure is detected by the pressure detector 29. Accordingly, the conveyor drive device 9 is operated via the signal converter 30, and when the clinker layer becomes thick and the pressure in the cooling air chamber 17 rises above a specified value, the oscillating conveyor 8 is fast-forwarded. Conventional technology involves slow-feeding the swinging conveyor 8 when the pressure drops below a specified value, that is, when the clinker layer becomes thin, but it is possible to fast-forward the swinging conveyor 8 when the amount of clinker increases. Although the clinker layer thickness can be made to a specified thickness, cooling air is insufficient and the clinker temperature at the clinker discharge port 10 increases.

Therefore, when the signal value from the signal converter 30 increases, the damper 35 of the blower 23 is opened to increase the amount of cooling air, thereby making the temperature of the discharged clinker at the clinker discharge port 10 constant.

Since the amount of clinker and the signal value sent from the signal converter 30 are in a proportional relationship, it is easy to balance the amount of clinker and the amount of cooling air by opening and closing the damper 35 depending on the signal value. Since it is necessary to consider the time for the clinker to pass over the cooling air chamber 18, a time lag calculator 32 is provided, and if the damper 35 is required, the damper 35' is opened and closed only for the time it takes for the clinker to pass through the cooling air chamber 18. By delaying the cooling air chamber 1 in a timely manner.
By continuously changing the amount of cooling air 9, the clinker temperature at the clinker discharge port 10 can be kept constant. In order to protect the machine from the heat of the clinker, a limiter 34 is provided to prevent the damper from opening below a certain degree.

By implementing the present invention, even if the amount of baked ingots at the inlet of the clinker quenching machine changes, it is possible to always cool the recovered air to the specified value without lowering the temperature, and the quenching machine itself can be made smaller. In addition, the clinker quenching machine also provides various effects such as the advantages of this cooling.

[Brief explanation of drawings]

FIG. 1 is a vertical cross section and a wiring system diagram of an apparatus according to the present invention, and FIG. 2 is a curve showing changes in the amount of high-temperature clinker from a rotary kiln over time. 14... Partition plate, 17... Cooling air chamber at the high temperature clinker receiving end, 19, 20... Cooling air chamber beyond the recovery air range, 21, 22, 23, 24... Blower, 2
9...Pressure detector, 30...Signal converter, 32...Time lag calculator, 33...Controller, 34...Limiter,
35, 35'...damper.

Claims (1)

[Claims] 1. Heat recovery in the transfer space of high temperature clinker supplied from the rotary kiln using a partition plate hanging from the ceiling. 2.
A partition section corresponding to this partition plate is provided in the middle, and a plurality of cooling air chambers are formed under the grate, and the air pressure signal of the first cooling air chamber on the kiln side is In the method of cooling high-temperature clinker to a specified value using an oscillating grate quencher that controls the drive speed of the grate and the amount of cooling air supplied, the pressure signal in the first cooling air chamber on the kiln side is used to control the damper via a time lag calculator. give a signal,
Based on this damper control signal, the area under the grate in the cooling range after the heat recovery secondary air range is formed into multiple rooms with partition plates, and cooling air is supplied to each room from an independently operated blower corresponding to each room. The transfer speed on the grate of the thick layer portion or thin layer portion caused by the change in the layer thickness of the first chamber of the rotary kiln outlet is predicted from the grate speed, and A clinker temperature control method comprising controlling a damper of a cooling air supply pipe in a chamber corresponding to passage through a thin layer part to control discharged clinker temperature. 2. The clinker temperature control method according to claim 1, characterized in that the pressure signal of the first cooling air chamber on the kiln side is passed through a time lag calculator, a regulator, and a limiter in this order, and a damper control signal is sent to the damper.