JPH0632191Y2 - Vertical mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a vertical mill with an air flow drying chamber for air flow drying a preliminary crushed raw material.

[Prior Art] In general, cement is manufactured by crushing raw materials by a crusher → drying the crushed raw materials by a rotary dryer (drying process) → crushing the dried coarse crushed raw materials by a tube mill (horizontal type) (crushing process) ) → Performed through each process of firing by rotary kiln.

However, in the case of the above manufacturing process, the rotary dryer becomes large and the maintenance cost is large, and if the dried coarsely crushed raw material is crushed into fine particles of 10 to 20 μm at once with a tube mill, the power consumption in the tube mill will be large. There was a problem of becoming.

Therefore, in recent years, when a new cement manufacturing facility is installed,
In order to save power consumption, a vertical mill is installed in place of the tube mill so that pulverization can be performed simultaneously with drying in the drying and pulverizing process.

[Problems to be solved by the invention] However, when the cement manufacturing facility is an existing facility,
Removing the tube mill and installing a new vertical mill is
This will lead to soaring equipment costs.

The present invention has been made in view of the above circumstances and has an object to reduce power consumption and to simplify a drying process even in a cement manufacturing facility equipped with a tube mill.

[Means for Solving the Problems] The present invention is provided with a nozzle for supplying primary hot gas along with a crushing table and a crushing roller, preliminarily crushes the crushed raw material supplied, and heats and dries the preliminary crushed raw material with the primary hot gas. A vertical mill capable of floating and carrying while being provided with an airflow drying chamber provided above the mill casing with a conduit for introducing secondary hot air.

[Operation] The preliminary crushed raw material preliminarily crushed on the crushing table by the crushing roller is heated and dried by the primary hot gas, suspended and transported, and sent to the airflow drying chamber, and further heated and dried by the secondary hot gas. While being suspended and transported.

[Embodiment] An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the present invention, in which 1 is a vertical mill, which is an undried coarsely crushed raw material that has been crushed by a crusher and dried before being sent to a tube mill, and has an average particle size of 500 μm. It is for pre-grinding to some extent.

The vertical mill 1 is provided with a rotatable crushing table 3 and a crushing roller 4 inside a mill casing 2, and the crushing raw material 6 supplied from the crusher in the preceding stage to the inside of the mill via a crushing raw material feeding pipe 5 is crushed by a crushing roller 4. It can be crushed on the crushing table 3. A nozzle 8 for introducing the primary hot gas 7 into the mill casing 2 is installed near the side of the crushing table 3 inside the mill casing 2, and the primary hot gas 7 floats while heating the preliminary crushing raw material 15. , Can be transported. Further, the coarsely crushed raw material input pipe 5 is connected to the upper crusher.

The drying chamber casing 10 of the airflow drying chamber 9 is integrally installed on the mill casing 2 of the vertical mill 1, and the secondary hot gas 11 is provided at the lower side of the drying chamber casing 10 with the secondary heating gas 11.
A conduit 12 for introduction into 10 is connected to the secondary hot gas 11
Thus, the preliminary crushed raw material 15 that has been floated and conveyed from the vertical mill 1 can be further floated and conveyed while being heated.

The drying chamber casing 10 is provided with a collecting cyclone via a conduit 13.
The preliminary crushed raw material 15 connected to the collection cyclone 14 can be supplied from the collection box 16 to the tube mill in the subsequent stage via the conduit 17 and the preliminary crushed raw material 15 can be supplied.
The separated gas 19 can be discharged from the conduit 18 to the outside by a blower.

Unlike the conventional cement manufacturing equipment, a rotary dryer is not required, and the crushed raw material 6 crushed by the crusher is supplied to the vertical mill 1 from the crushed raw material feeding pipe 5 in an undried state.
The crushing table 3 and the crushing roller 4 cooperate with each other to carry out preliminary crushing to an average particle size of about 500 μm.

On the other hand, the primary hot gas 7 is discharged from the nozzle 8 into the mill casing 2
The preliminarily pulverized raw material 15 is introduced into the interior of the air flow drying chamber 9 while being heated and dried by the primary hot gas 7 while being suspended and transported.
Is introduced into the drying chamber casing 10.

In addition, the secondary hot gas 11 is introduced into the drying chamber casing 10 of the airflow drying chamber 9 from the conduit 12, and the preliminary pulverized raw material 15 floated and conveyed by the primary hot gas 7 from the vertical mill 1 is It is floated and transported while being heated and dried by the secondary hot gas 11, and is collected from the air flow drying chamber 9 via the conduit 13 into a cyclone 14
Sent to.

Thus, in the collection cyclone 14, the preliminary pulverized raw material 15 is separated from the secondary hot gas 11 and collected in the collection box 16, quantitatively cut out from the collection box 16 and the tube mill in the latter stage from the conduit 17. Sent to. The gas 19 separated from the preliminary crushed raw material 15 is the conduit 18
Is discharged from the outside.

The raw material particle size preliminarily ground by the vertical mill 1 may be coarser than the raw material particle size finely ground by the tube mill, and thus a classifier such as a normal vertical mill may not be provided. However, if there is no classifier, the retention time of the preliminary crushed raw material 15 in the mill becomes short, and the preliminary crushed raw material 15 cannot be sufficiently dried.

However, as described above, the airflow drying chamber 9 is provided above the vertical mill 1.
By providing, the preliminary crushing raw material 15 can be sufficiently dried. In the drying chamber casing 10, the wind speed is
Primary hot gas 7 and secondary hot gas to be 10 to 25 m / sec.
11 is supplied, and the heat quantity of the secondary hot gas 11 supplied from the conduit 12 is set to approximately 1/3 or more of the total necessary heat quantity.

The hot gas required for drying was divided into the primary hot gas 7 and the secondary hot gas 11 for the following reason. That is, a large amount of hot gas is required to dry the preliminary crushed raw material 15, but if all of it is supplied from the nozzle 8 of the vertical mill 1, the nozzle 8
This is because the pressure loss of the hot gas piping system until it passes through becomes large, and the power of the blower for hot gas feeding becomes large.

As described above, if the primary hot gas 7 and the secondary hot gas 11 are divided, the pressure loss in the piping system of the nozzle 8 is reduced, so that the blower power can be reduced as a whole.

In addition, in the embodiment of the present invention, the case where the classifier for the preliminarily pulverized raw material is not provided has been described, but it is possible to implement even if the classifier is provided, and other various changes may be made without departing from the scope of the present invention. Of course, it can be added.

[Effects of the Invention] As described above, according to the vertical mill of the present invention, it is possible to reduce the electric power required for crushing the coarsely crushed raw material to a predetermined particle size, and it is possible to reduce the electric power consumption rate. Also, various excellent effects such as improvement of crushing ability and drying ability can be achieved.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of the present invention. In the figure, 1 is a vertical mill, 2 is a mill casing, 3 is a crushing table, 4 is a crushing roller, 6 is a crushing raw material, 7 is primary hot gas, 9 is an air flow drying chamber, 10 is a drying chamber casing, 11 is two. Secondary hot gas, 12 is a conduit, and 15 is a preliminary crushed raw material.

Claims (1)

[Scope of utility model registration request] 1. A crushing table and a crushing roller are provided with a nozzle for supplying primary hot gas, and the supplied crushing raw material can be pre-crushed, and the preliminary crushing raw material can be heated and dried by the primary hot gas while floating and carrying. In the vertical mill, the vertical mill is characterized in that an airflow drying chamber provided with a conduit for introducing secondary hot air is provided above the mill casing.