SU773407A1 - Method of cooling rotary furnace lining - Google Patents

Description

one

This invention relates to a technique for cooling the lining of a rotary kiln.

A known method of cooling the lining of a rotary kiln with the aid of irrigation of the kiln body. According to a known method, water is generated on the jacket on the cooled portion of the furnace above the hull. The water in contact with the hull during heat exchange takes away heat from the hull and the inner liner layers of the refractory, as a result of which the refractory masonry is cooled. The heated water from the furnace body is collected in a reservoir, from which it is pumped to industrial wastewater.

However, in a known method, the heat removed from the cooled section of the furnace is not further involved in the process of firing the material, but is discharged as production loss. Considering that water is an intensive cooling agent, the heat loss during cooling is relatively significant and amounts to 3-7% of the total amount of thermal energy consumed to roast the material in the furnace.

The air cooling method of the lining is known. In this way the lining

in the cooling zone of the furnace, it is cooled by a stream of passing secondary air necessary for burning the fuel. The lining of the sintering zone is cooled forcibly directed at the furnace body or by a naturally circulating air stream 1.

The disadvantage of this method is the relatively low cooling efficiency of the lining and significant heat loss during cooling, which is 2-4% of the total amount of thermal energy consumed for firing the material.

The purpose of the invention is to increase cooling efficiency and reduce heat loss.

This goal is achieved by the method of cooling the lining of a rotary kiln in the cooling zone to the inner surface of the upper roof above the burner, directing the dust-air flow of the raw mix at an angle of i-35 relative to the axis of the burner at a speed of 30-120 m / s .

The drawing shows schematically a rotary kiln.

Claims (2)

The rotary kiln 1, including a conical transition section 1 K, is lined inside 2. The narrowed portion of the kiln 1 is connected to the furnace head 3. In the cavity of the kiln 1 a fuel burner 4 is installed, inside which a conduit 5 is placed to feed the powdered raw material 6 for cooling the lining 2. Through the outlet 6 to the lining of the conical section 1K of the cooling zone of the furnace 1, a stream 7 of the dusty air mixture is directed. The jet 7 is fed to a conical transition section of lining 2 above the burner 4, and the angle of inclination of the jet 7 is set based on the passage of the jet 7 under the upper arch of lining 2 above the burner 4 and the torch 8. The jet 7 of the dust-blowing raw mixture washes a conical lining section, then passes over the lining surface of the upper arch of the cooling zone. A stream 7 passing along the furnace 1 near the surface of the lining 2 protects the lining from thermal radiation of the cooled clinker and thermal radiation from the fuel torch 8. In addition, the stream 7 of the dust-air raw mixture cools the lining 2 and directly heats it with direct contact and heat transfer. When heated, the raw mix in the jet leaves the cooled lining area, precipitates to the main layer of the material and participates in the technological process. The cooling rate of the lining is controlled by the amount of raw material injected. The length of the section of the cooled lining is controlled by the speed of the injected raw material mixture, and the speed of injection of the raw material mixture is 30-120 m / s. The most intensive cooling of the lining is achieved by supplying a dust-air jet to the tapered transition section at an angle of 10-35 ° relative to the axis of the burner. In addition, when the jet is fed to the tapered transition section at an angle of 10–35 ° with a jet injection rate of more than 30 m / s, a dusty air flow passes over the burner under the upper arch of the lining and blows the material into the furnace sintering zone. Increasing the jet blowing speed of more than 120 m / s at an angle of 10-35 ° is impractical, as an increase in speed reduces the time the jet contacts the lining, and therefore the lining is not efficiently cooled, and the jet is not efficiently heated. To further cool the lining, a dust-air flow of the raw mix at an angle of 25 ° relative to the axis of the burner at a speed of 75 m / s is directed to the cooling zone to the tapered transition section. In this case, the lining durability is markedly increased, and in all parts of the cooling zone and sintering zone is 207 days. In addition, the temperature of the furnace body in the cooling zone and in the sintering zone decreases by an average of 89 °. The advantage of this method is intensive cooling of the lining of the conical transition and near the located portion of the lining of the cooling zone, as well as intensive cooling of the lining of the furnace sintering zone. It is known that the lining of the tapered transition section is relatively often destroyed due to the high temperature. In addition, the lining of the cooling zone at its elevated temperature is significantly faster rubbed off by clinker, and the calcination product, for example, cement clinker, cools more slowly. The elevated temperature of the surface of the refractory layer in the cooling zone and in the sintering zone increases the temperature of the furnace body, and therefore increases the thermal radiation into the external environment. In addition, the heat obtained by the cooling agent (a stream of dust-air raw material mixture) participates in the technological process of burning the material, which in turn reduces the specific consumption of thermal energy for the product being calcined. Claims The method of cooling the lining of a rotary kiln, including cooling the kiln body with an air flow, is characterized in that, in order to increase the cooling efficiency and reduce heat loss, the air-air mixture flows to the inner surface of the upper roof above the burner. at an angle of 10-35 ° relative to the axis of the burner at a speed of 30-120 m / s. Sources of information taken into account in the examination 1. Handbook of cement production. NIICEMENT M., Gosstroyizdat, 1963, p. 446-447.