JPH01284342A - Grinding machine - Google Patents

Abstract

PURPOSE:To substantially improve grinding efficiency by compressing and grinding material to be ground under high pressure between the upper-step roll and one of the lower-step rolls and also rotating two rolls of the lower step to the same direction. CONSTITUTION:Material 5 to be ground such as a cement raw material is fed between the upper and lower rolls 2, 3 from a material feed hopper 1, compressed and ground. The obtained material 6 to be ground is introduced between two rolls 3, 4 of the lower step. Since these two rolls 3, 4 are rotated to the same direction, the material 6 pinched between the rolls 3, 4 receives both the force acting downward and the force acting upward. One part 7 of the material to be ground which has been crushed by compression and shearing force with such a way falls between the rolls 3, 4 and large parts are again compressed and ground between the rolls 4, 2 of both the lower step of the opposite side and the upper step and the material 8 to be crushed is taken out.

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a material pulverizer, and more particularly to the pulverization of materials such as limestone, clay, and cement clinker, which are raw materials for cement.

b. Prior Art Conventionally, as a method for pulverizing "brittle materials", for example, Japanese Patent Laid-Open No. 53-106968 proposes a compression pre-pulverization method using a roll mill.

Problems to be Solved by the C0 Invention However, according to the above method, the material to be crushed under high pressure compression is agglomerated and becomes plate-shaped. In addition, if a large lump is caught between the rolls, the force will be concentrated only on that part, and the object will pass through without being crushed, or in places where it is difficult to apply force, such as on both sides of the rolls, it will pass without being crushed. There is something to do. In other words, because some objects become plate-shaped or pass through without being crushed, 2
Next mill is required. However, ■ Since it is not possible to separate the fine powder that should originally become a product, energy is wasted on the secondary mill side, and ■ Because some particles pass through without being crushed, the conditions on the secondary mill side are There are drawbacks such as having to mix with the material to be crushed that passes through without being crushed, which impairs efficiency.

d. Means for Solving the Problems The present invention provides a pulverizer that significantly improves pulverization efficiency and enables a simple system capable of mass processing. Two rolls are provided in the lower stage, applying pressure between each roll so as to compress the supplied material to be crushed, and supplying the material to be crushed between the upper roll and one of the lower rolls. The hopper is opened, one of the upper roll and the lower roll is rotated in the biting direction with respect to the hopper, and the other lower roll is rotated in the same direction as the lower roll. It is in a crusher.

According to the present invention, the material to be crushed is subjected to high-pressure compression and pulverization between the upper and lower rolls, and the two lower rolls rotate in the same direction, so the material to be crushed sandwiched between them is subjected to downward force,
Upon receiving the upward force, the pieces are pulverized by the compression force and shearing force and some of them fall, while most of them are compressed and pulverized again between the rolls on the lower and upper stages on the opposite side. In addition, on the first stage side, for example, when a large lump is caught at both ends of the roll, there are objects to be crushed that pass through without being compressed and crushed.
This material to be crushed is sandwiched between the two rolls on the lower stage and pulverized by compression force and shearing force, and is further compressed and crushed again between the rolls on the second stage, so that all of the material to be crushed is
At least once, undergo compression crushing. Therefore, by using the pulverizer according to the present invention, the particle size of the material to be pulverized becomes below a certain level, the conditions on the secondary mill side can be adjusted to the optimum pulverizing conditions, and the pulverizing efficiency can be significantly improved.

The drawing conceptually shows a crusher according to the present invention.
is a material supply hopper, 2 is an upper roll, and 3.4 is a lower roll. The rotation axes of each roll 2.3.4 are arranged parallel to each other.

In the illustrated embodiment, the lower roll 3 is rotated in a fixed position, whereas the roll 2.4 is moved in the direction of the open arrow by suitable means, for example by mounting a hydraulic pressure device on the rotary shaft bearing. and apply pressure. Note that the line arrow shown along the white arrow indicates that the distance between roll 2.4 and roll 3 increases due to biting of the material to be crushed. A spacing is provided between the rolls to prevent direct contact between the rolls.

e. Operation Now, the material to be crushed 5 is transferred from the material supply hopper 1 to the roll 2.
, and compressed and crushed. The obtained material to be crushed 6 enters between the two lower rolls 3.4. However, since the two lower rolls 3.4 rotate in the same direction, the material to be crushed 6 sandwiched between them is affected by the force acting downward and the force acting upward (
A portion 7 is crushed by compression and shearing force and falls from between the rolls 3.4, but the majority is compressed and crushed again between the rolls 4.2 on the lower and upper stages on the opposite side. The crushed material 8 is taken out.

That is, the material to be crushed 6 is crushed by compressive force and shearing force, and is
Since it is crushed twice between
Shattered on average.

Note that the rotational speeds of rolls 2 and 3.4 may be the same, but the speeds can be changed.For example, if the rotational speed of roll 2 is increased and the rotational speed of rolls 3 and 4 is sequentially decreased, each roll Shearing force is applied between the two, allowing for finer pulverization.

Roll 2.3.4 diameter is 1000mm, roll width is 100mm
When cement clinker was compressed and pulverized with a circumferential speed of 1.2 mm, a compression force of 100,100 O/cd between rolls 2 and 3, and a compression force of 250 kgf/- between rolls 2.4 and 3. The particle size distribution of the crushed material is 10fi
! i! The sieve residue was 0%, and the sfi sieve residue was 1%.

f. Effect of invention The present invention has made it possible to significantly improve the grinding efficiency.

[Brief explanation of the drawing]

The drawing is a conceptual diagram of a crusher according to the present invention. 1... Hopper, 2, 3.4... Roll.

Claims (1)

[Claims] One roll is provided on the upper stage and two rolls are provided on the lower stage, applying pressure between each roll so as to compress the supplied material to be crushed. A hopper for supplying material is opened, one of the upper roll and the lower roll is rotated in the biting direction with respect to the hopper, and the other roll of the lower stage is rotated in the same direction as the one roll of the lower stage. A crusher characterized by comprising: