JPS589915B2 - Anzatu formation prevention device and method in cement firing process - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to the prevention of ANZA formation during the cement firing process.

In cement firing, when heavy oil is used as a heat source, steam is required to preheat the heavy oil.

Conventionally, a boiler was installed and heavy oil was burned to create this preheated steam, or an air quenching cooler (hereinafter referred to as FAQC) was installed.
Steam is obtained by passing the excess exhaust gas (abbreviated as ) to a waste heat recovery boiler.

In the cement firing process, dust containing low-melting substances such as alkali deposits and grows to form ants7, which impedes normal operation and deteriorates thermal efficiency, and in severe cases can lead to inoperability.

To deal with this, the usual methods are to use a push rod or a Takada water stream to manually plunge the fish from the outside on a regular or irregular basis, or to cool it by placing a water-cooled box at the Anzatu attachment location to prevent Anzatu attachment. There is.

In the method of dropping Anzatu, cold air is sucked in from the outside through the cleaning hole during the removal work, which obstructs normal ventilation, resulting in reduced production and deterioration of thermal efficiency during this period.

In addition, in the method of installing a water-cooled box, a group of tubes is placed in the box, and the space inside the box is filled with heat transfer oil, which becomes hot and causes the cooling water in the group of tubes to cool. The wall surface of the preheating device for the cement firing process is indirectly cooled through the heat transfer oil as steam or hot water, so the cooling efficiency is poor and the equipment itself is complicated.

A first aspect of the present invention is an anzatu formation prevention device for a preheating device in a cement firing process, characterized in that a group of water pipes for cooling the wall surface of the preheating device is installed in the preheating device for the cement firing process.

Furthermore, the second invention is a preheating device for a cement firing process,
A cement characterized in that a group of water pipes is installed, and the radiated heat and exhaust heat from the preheating device are exchanged with the supply water in the group of water tubes to cool the wall surface of the preheating device and prevent the formation of Anzatu. This is a method for preventing the formation of anzatz in a preheating device during the firing process.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Application to Repol preheater FIG. 1 shows the structure of Repol preheater and the anzatz attached thereto.

Raw material 1 is supplied in granular form from a supply port 3, moves on a moving grid 4, and is sent to a kiln 9 via a scraper 7 and a supply guide 8 while exchanging heat with gas from a kiln 9 along the way. .

On the other hand, the exhaust gas from the kiln 9 enters the preheater chamber 6 & is sucked by the primary fan 10, and is transferred to the raw material layer 1 and the moving grid 4.
It passes through to the primary fan 10, and from there it flows into the second chamber 5.
Similarly, it passes through a raw material layer and a moving grid (and is sucked into the secondary fan 11, from where it is discharged to the outside).

The small particles of raw material that have fallen through the gaps in the moving grid are transferred to the hopper.
Collected to 12.

The exhaust gas from the kiln 9 contains dust, and this is poured into the preheater, the ceiling 14 of the recess, and the ceiling 17 of the same room.
Preheater sink, side wall 16 in the same room side wall 18
It is attached to the island, forming Anzatu.

Further, it is deposited on the raw material layer, and when it is carried along with the raw material and enters the kiln 9, it adheres and solidifies on the slope of the engaging guide 8, forming an anzatu.

In contrast, the conventional method is to provide cleaning holes at various locations in the ceiling 14 of the raw material inflow section to the kiln, the side walls 15 and 16 of the same section, and the ceiling 17 of one room, and the Anzatsu is dropped from there using a high-pressure water stream. Met.

In this invention, as shown in FIG. 2, the ceiling 19 of the raw material inflow section to the kiln, the front side wall 20 of the section, the left and right side walls 21 of the section,
Furthermore, water pipe groups of 1-inch carbon steel pipes for high-temperature piping were laid on the brick wall soil on the side walls 23 of each room, and a water cooling box 22 was installed on the supply guide 8 to allow cooling water to flow therethrough.

According to this method, the epiphytic growth of the Japanese lanternfly, which had been a problem in the past, was significantly reduced, and the purpose of preventing the Japanese lanternfly was achieved.

Next, we conducted a steam generation experiment by squeezing the cooling water, and were able to obtain the normally used saturated steam at 150°05 atm.

The heat transfer coefficient of the water pipe at this time is 2 7 Krai / m2
) 1'0.

Based on this experiment, we designed and constructed a group of water pipes to obtain the steam volume of 22 kg/t required for preheating heavy oil for firing.

Although there is sufficient wall area on the ceiling and side walls of the area where raw materials flow into the kiln of the great preheater to install the water pipes necessary for steam generation, the water pipes installed in important areas are used as they are to prevent Anzatu from sticking. The additional amount was installed in two preheater rooms.

This is also intended to address changes in steam requirements between summer and winter.

By carrying out the above construction work and operating the plant, we were able to achieve the intended objectives of preventing Anzatu and generating steam.

Embodiment 2 Application to suspension preheater FIG. 3 shows a suspension preheater kiln (SF type) with an auxiliary combustion furnace.

In Fig. 3, the raw material is introduced from 25, mixes with the exhaust gas coming up from below, exchanges heat, is separated in the first cyclone 28, and then descends downward while sequentially mixing with the exhaust gas, exchanging heat, and separating. come.

In this example, the cyclone 30 enters the auxiliary combustion furnace 32, where it is calcined by the auxiliary combustion furnace 37, and the cyclone 3
1, after separation, enters the kiln 9 via the kiln inlet 35,
It is burned by the kiln combustion fuel 36 and becomes clinker,
It enters an air quenching cooler 27 (AQC), is cooled with air, and is discharged.

After cooling the clinker, the air forced in the AQC is divided into three parts: one passes through the kiln, the other passes through the volute chamber 33 and the auxiliary combustion furnace 32, and then the two join together, ascend the suspension tower, and are separated from the exhaust gas. The other one is discharged as AQC surplus exhaust.

In this system, low-melting and low-boiling substances such as alkalis contained in the raw materials are volatilized in the kiln 9, solidified by the raw materials as they rise with the gas, and attached to the raw materials, forming a circulation path that enters the kiln again and becoming concentrated. When the temperature reaches a point where the fusion property becomes strong, it grows attached to the brick surface of the device and forms anzatu.

In Fig. 4, there is a kiln inlet 35, a rising wind pipe 34, and a swirl chamber 3.
It is 3.

A water pipe group 38 in the swirl chamber 33, a water pipe group 39 in the rising wind pipe, and a water pipe group 40 in the inlet of the kiln are installed at these positions to flow water and cool it, thereby preventing the formation of Anzatu, while evaporating the water. It is extracted as steam and used for preheating heavy oil or for other purposes.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a Lepore type preheater, and its A-A
' Cross-sectional view, Figure 2 is a cross-sectional view of a Lepore type preheater in which the water tube group of the present invention is installed at each position, Figure 3 is an explanatory diagram of a cement clinker manufacturing process using a suspension preheater kiln with an auxiliary furnace, and Figure 4 is a diagram volute chamber, rising wind pipe,
It is an explanatory view of a group of water pipes of the present invention installed in a kiln inflow part. 1... Raw material, 2... Great flame heater, 3... Raw material supply port, 4... Moving grid, 5... Preheater 2nd room, 6...
... Preheater chamber 1, 7 ... Scraper, 8 ... Supply guide, 9 ... Kiln,
10...1st fan, 11...2nd fan
Next fan, 12...Hopper, 13...
・Partition wall, 14...Ceiling of the part where raw materials flow into the kiln, 15...Side wall of the part where raw materials flow into the kiln (perpendicular to the longitudinal direction of the kiln), 16...・Side wall of the part where raw materials flow into the kiln (parallel to the longitudinal direction of the kiln), 1
7... Preheater room side wall ceiling, j8...
... Side wall of the preheater room, 19 ... Water pipes attached to the ceiling of the area where raw materials flow into the kiln, 20.
...A group of water tubes attached to the front side wall of the part where raw materials flow into the kiln, 21...A group of water pipes attached to the left and right side walls of the part where raw materials flow into the kiln, 22...・
A water pipe attached to the sloped wall where raw materials flow into the kiln,
23... Water pipe group attached to the side wall of one preheater room, 24... Water pipe group attached to the back of the partition wall of two preheater rooms, 25... Raw material input port, 26・
...Suspension preheater with auxiliary combustion furnace, 27
...AQC, 28...4 stage cyclone, 29...3 stage cyclone, 30...
2-stage cyclone, 31...1-stage cyclone, 3
2...SF type auxiliary combustion furnace, 33...Vortex chamber, 34...Rising wind pipe, 35...Kiln inflow, 36...・Kiln firing fuel, 37...
... Fuel for the auxiliary combustion furnace, 38 ... Water tube group attached to the volute chamber, 39 ... Water tube group attached to the rising wind pipe, 40 ... ... Water tube group attached to the kiln inlet. Water pipe group.

Claims (1)

[Scope of Claims] 1. Anzatu formation prevention device for a preheating device in a cement firing process, characterized in that a group of water pipes for cooling the wall surface of the preheating device is installed in the preheating device for the cement firing process. 2. The apparatus according to claim 1, wherein the water tube group is installed on the ceiling and side wall of the raw material pouring part of the preheating device, on the inclined wall for supplying raw material to the rotary kiln, on the gas rising wind pipe, and on the swirl chamber. 3. The apparatus according to claim 1 or 2, wherein the cement firing step comprises a Lepore type preheater kiln. 4. The apparatus according to claim 1 or 2, wherein the cement firing process comprises a suspension preheater kiln or a suspension kiln with an auxiliary combustion furnace. 5 A group of water pipes is installed in the preheating device for the cement firing process.7
A preheating device in a cement firing process, characterized in that the radiated heat and exhaust heat from the preheating device are exchanged with the supply water in the water tube group to cool the wall surface of the preheating device and prevent the formation of anzatu. How to prevent Anzatu formation. 6. A group of water pipes is installed in the ceiling of the raw material pouring part of the preheating device, the inclined wall for supplying raw material to the rotary kiln, and the swirl chamber along with the gas riser wind pipes, and the radiated heat and exhaust heat from these are combined with the supply water in the water pipes. 6. The method according to claim 5, wherein the preheating device is cooled at these locations to prevent the formation of ants. 7. Claim 5 or 6 in which the cement furnace formation process is comprised of a Lepore type play heater kiln.
The method described in section. 8. The method according to claim 5 or 6, wherein the cement firing step comprises a suspension preheater kiln or a suspension kiln with an auxiliary combustion furnace.