JPS6065750A - Cement calcining apparatus using fuel containing large quantity of ash content - 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 cement calcination device that utilizes fuel containing a large amount of ash such as low quality coal, bottons, and industrial waste.

Conventionally, in calcining cement raw materials using fuel containing a large amount of ash, various types of abrasives have been directly supplied to a calciner and burned within the calciner. Therefore, the ash content is mixed into the cement raw material and becomes part of the cement clinker raw material, which has the advantage of increasing clinker production. is extremely difficult to manage. In other words, when driving,
From the perspective of maintaining the calciner outlet gas temperature at a predetermined value,
The amount of injected fuel increases or decreases depending on the change in the amount of heat required for burning clinker, and the effect on clinker quality cannot be eliminated.Also, the amount of ash content is too high, and the amount of fuel must be suppressed when blending the raw materials. There may be cases where this is not possible.

The present invention aims to reduce fuel costs in the field of cement production by using coal, especially low-quality coal, coal, oil shale, industrial waste containing combustibles, etc., which adversely affects the quality of cement clinker. It is an object of the present invention to provide a cement calcination device that can effectively collect the heat of the fuel without causing any problems, and can utilize the ash obtained as a secondary by-product as an extender for clinker.

Therefore, the configuration of the present invention includes a combustion furnace having dust collection performance provided in the middle of a high-temperature air duct that supplies high-temperature air from a clinker cooler to a calciner, and the combustion furnace has an ash content. The combustion furnace is characterized by having a burner that burns fuel containing a large amount of ash, and an ash discharge chute that discharges ash collected in the combustion furnace to the outside of the system.

An embodiment of the present invention will be described below with reference to the drawings.

In the figure, 1 is a suspension preheater, 2 is a lowermost cyclone of the preheater 1, 3 is a calciner, 4 is a rotary kiln, 5 is a clinker cooler 2. A high temperature air duct is supplied as secondary air for combustion, 7 is a powder cement raw material supply device, 8 is a calcining raw material supply chute, 9 is an exhaust duct, 10 is a kiln start-up duct, 11 is a preheated raw material from the preheater 1 This is the supply chute. Furthermore, in the figure, solid line arrows indicate the flow of raw materials and clinker, and dotted line arrows indicate the flow of air and gas. Among these, arrow 12 indicates the flow of fired high-temperature clinker, arrow 15 indicates the flow of clinker that has been cooled and becomes a product, and arrow 14 indicates the flow of gas from the calciner 5 to the cyclone 2. indicates the flow of the calcined raw material carried by the gas flow. Further, 16 is a calciner burner that uses normal fuel, and 17 is a kiln burner that uses normal fuel. Note that the process up to this point is the same as the conventional cement firing equipment with a calcining furnace.

To explain further, reference numeral 18 denotes a combustion furnace having dust collection performance, which is installed in the middle of the high-temperature air duct B. In this embodiment, it is a cyclone type combustion furnace. 19 is a combustion furnace burner that burns fuel containing a large amount of ash; 20 is a feeder;
A wind fan, 21 is a cyclone, 22 is a cyclone inlet air pipe that connects the discharge side of the blower 20 and the inlet side of the cyclone 21, and 23 is a part between the dust outlet of the combustion furnace 18 and the cyclone inlet air pipe 22 24 is a cyclone outlet air pipe connecting the air outlet of the cyclone 21 and the middle of the high temperature air duct 6, 25 is a low temperature ash discharge chute, and 26 is a high temperature ash discharge chute connecting the combustion furnace 18. An atmospheric air suction pipe 27 that sucks in a small amount of atmospheric air to cool the furnace wall is a main exhaust duct that connects a main exhaust fan (not shown) and the upper part of the suspension preheater.

In the cement manufacturing equipment configured as shown in the diagram,
The fuel containing a large amount of ash is combusted in a combustion furnace 18 by a burner 9. This results in 60
High temperature air of about 0 to 700°C is 1200 to 1300°
The temperature is raised to approximately C and is supplied to the calcining furnace 3. That is,
The amount of heat required in the calciner in a normal process is about 1,000 yen by using fuel with a high ash content.
The essential parts of the grains are collected by the twister 18 and discharged from the ash discharge chute 23, but since the ash has a high temperature, the cyclone 21 is used to effectively utilize the heat.
and exchange heat with the room temperature air from the blower 20.

The air heated by the cyclone 21 can also be effectively used as primary air for the calciner burner 16 and kiln burner 17, but in this embodiment.

The air is supplied from the outlet air pipe 24 to the middle of the high-temperature air duct B before the combustion furnace 18. In addition, the ash cooled by the cyclone 21 is discharged from the system through the ash discharge chute 25, but since this ash is a fuel residue, it can be mixed with clinker and used as cement powder without any chemical reaction and is just cement powder. It can be used as a bulking agent. As described above, the suction air from the atmospheric suction pipe 26 is divided and supplied to several locations along the swirling flow of the combustion furnace 18 in order to prevent ash from adhering to the inner wall.

As mentioned above, in cement firing equipment equipped with a calciner, when attempting to effectively utilize the heat by burning fuel containing a large amount of ash, the chemical composition of the ash and the chemistry of the cement The quality (composition) of the product clinker often deteriorates due to different components, but in the present invention, dust is not collected in the middle of the high-temperature air duct that supplies high-temperature air from the clinker cooler to the calciner. Since a combustion furnace with high performance is installed and the fuel containing a large amount of ash is combusted in the combustion furnace, the quality of clinker is not deteriorated, and the fuel containing a large amount of ash can be burnt well and its calorific value can be used effectively. The ash content of the fuel after combustion is collected in the combustion furnace and taken out of the system, and the cement cream product is
It can be effectively used as a force extender.

[Brief explanation of drawings]

The figure is an explanatory diagram showing one embodiment of the present invention. 1. Suspension brake heater, 216. Bottom stage cyclone, 3. Calciner, 4. Rotary kill.
5... Clinker cooler, 6... High temperature air duct, 1
8... Combustion furnace, 19... Combustion furnace burner, 20...
Blower, 21... Cyclone, 22... Cyclone inlet air pipe, 23... High temperature ash discharge chute, 24...
...Cyclone outlet air pipe, 25...Low temperature ash discharge chute, 26...Atmospheric suction pipe.

Claims (1)

[Claims] 1. A combustion furnace with dust collection performance is installed in the middle of a high-temperature air duct that supplies high-temperature air from a clinker cooler to a calciner, and the combustion furnace burns fuel containing a large amount of ash. A cement calcination device using fuel containing a large amount of ash, characterized by having a burner and an ash discharge chute for discharging ash collected in the combustion furnace to the outside of the system.