JPS59102452A - Shaft type mill - 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 vertical ball mill that finely grinds solid materials by stirring a solid material slurry together with a grinding medium.

Such a vertical ball mill consists of a cylindrical or polygonal cylindrical vertical container having an inlet at the lower end and an outlet at the upper end for receiving the pressurized slurry-formed material, and a shaft extending and rotatably supported; a plurality of disk-shaped or pin-shaped stirring members disposed on the shaft at intervals in the longitudinal direction; and rotating the rotating shaft. A drive device is provided, and the object to be processed in the slurry is pulverized by a pulverizing medium such as a hard ball placed in the container.

In such a vertical ball mill, the internal hard balls are
When the ball mill stops operating, it is tightly packed due to its own weight. In such a state, even if the rotating shaft is driven to rotate, an excessive starting torque acts on the rotating shaft and the engine may not start. However, when actually starting a ball mill, the rotating shaft is rotated while pumping the slurry, so in most cases, the pumped slurry is striated to the extent that hard balls are tightly packed, resulting in excessive startup. Even if torque is applied, startup is successful.

However, in cases where the amount of pumped slurry is small, generally,
It takes a long time to start, and in extreme cases it may not start. If the rotating shaft does not rotate easily, its drive motor will overheat.

Therefore, the present invention aims to provide a method for starting a vertical ball mill that can easily and reliably start a vertical ball mill by solving such startup problems, and a vertical ball mill that can carry out the method. .

That is, according to the present invention, there is provided a cylindrical container placed vertically with an inlet at the lower end and an outlet at the upper end for receiving the pressurized slurry processed material, and a cylindrical container placed vertically in the longitudinal axis direction of the container. a shaft extending and rotatably supported;
A plurality of stirring members are arranged on the shaft at intervals in the longitudinal direction thereof, and a drive device for rotating the rotation shaft is provided, and the grinding medium contained in the container is used to crush the to-be-processed material. When starting a vertical ball mill configured to carry out pulverization, compressed air is supplied from the lower end of the container to break the tightly packed state of the pulverizing medium inside, thereby reducing the starting torque of the rotating shaft. A method for starting a vertical ball mill is provided.

As described above, if compressed air is supplied to the bottom of the container at the time of startup, the grinding media can be floated and the tightly packed state can be broken. As a result, the starting torque of the rotating shaft is reduced, and the rotating shaft can be reliably moved. and can be started easily.

The method of the present invention includes a vertically placed cylindrical container having an inlet at the lower end and an outlet at the upper end for receiving the pressurized slurry-formed material, and a longitudinal direction of the container. comprising a shaft extending and rotatably supported, a plurality of stirring members arranged on the shaft at intervals in the longitudinal direction thereof, and a drive device for rotating the rotating shaft, A vertical ball mill configured to grind the object to be processed using a grinding medium placed in the container, comprising: an air inlet formed at a lower end of the container; and a connection between the air inlet and a compressed air source. According to the present invention, there is provided an on-off solenoid valve connected between the two, and a timer circuit that opens the on-off solenoid valve simultaneously with closing of a switch of the drive motor of the rotating shaft and closes the on-off solenoid valve after a predetermined period of time. This can be carried out by using a vertical ball mill.

If such a vertical ball mill is used, by turning on the drive motor switch, the necessary compressed air will be automatically supplied for a predetermined short period of time at the same time as startup, and the tightly packed state of the grinding media will be broken. , the ball mill can be started reliably and easily.

The present invention will be described in detail below with reference to the accompanying drawings.

The accompanying drawing is a longitudinal sectional view of a vertical ball mill in which the present invention is implemented. The ball mill includes a cylindrical container 1, an inlet 2 is provided at the lower end of the container, an outlet chamber 3 is provided at the upper end, and the outlet chamber 3 is provided with an outlet 3a. ing. Furthermore, inside the container 1, a rotating shaft 4 that penetrates through the upper end wall 1a of the container 1 and is rotatably supported extends in the longitudinal direction of the container. It is rotated by a drive device (not shown).

A plurality of stirring members 5 are provided at regular intervals in the longitudinal direction of a portion of the rotating shaft 4 located inside the container. The stirring member may be a disk provided with a plurality of holes, or a disk with a plurality of pins implanted around the circumference so as to extend radially. Furthermore, hard balls, for example, are placed in the container l as a grinding medium.

Furthermore, a partition wall 6 is attached to the upper part of the container 1 to divide the inside of the container into an outlet chamber 3 and a crushing chamber 7. The upper part 8 of the container is narrowed into a conical shape so that the diameter becomes smaller toward the outlet chamber 3. Further, a hole having a conical inner circumferential surface 9 whose diameter becomes smaller toward the outlet chamber 3 is formed in the partition wall 6, and a hole corresponding to the conical inner circumferential surface of the hole, that is, toward the outlet chamber side, is formed in the partition wall 6. A separation disk 11 having a conical outer circumferential surface 10 whose outer diameter is reduced is fixed to the rotating shaft 4 so as to fit into a hole in the partition wall 6 and rotated together with the rotating shaft. The gap 14 between the two conical surfaces 9 and lo is smaller than the diameter of the hard ball. And, if necessary, it may be smaller than the diameter of the unpulverized particles.

Moreover, if necessary, the parting disk 11 and the parting wall 6 near the conical surface on the side of the grinding chamber may be lined with a wear-resistant metal 12, 13.

Further, an auxiliary stirring member 17, which is constituted by a truncated conical member 16 into which a plurality of pins 15 extending obliquely downward and outward are implanted, is fixed to the lowermost end of the rotating shaft 4 by screws 17a. These pins 15 extend close to the lower end wall 1b of the container, and a plurality of pins, for example four, are provided at equal angular intervals.

In the vertical ball mill having such a configuration, according to the present invention, for example, a plurality of air inlets 18 are provided in the lower end wall 1b of the container l, and pipes 19 are connected to these, and furthermore, these pipes 19 are connected to flow rate regulating valves. 20 and on/off solenoid valve 21
via a compressed air source 22, such as a compressed air tank of a compressor. And the flow control valve 2o
This is to ensure that the amount of compressed air ejected from each air introduction port 18 is equal to each other, and may be omitted in some cases. On the other hand, the solenoid 21 of the on-off solenoid valve 21
a is connected in series to a switch 24 that opens and closes in conjunction with a switch 23 of a motor that drives the rotating shaft 4, and a contact b of a delay activation relay R;
The contact Rh is connected in parallel to the series circuit of the solenoid 21a, so that when the switch 23 is closed, the switch 24 is simultaneously closed to energize the solenoid 21a and open the valve 21, and then a predetermined short delay time. After that, the delayed activation relay R operates to open its contact Rh, and the valve 2 returns to the closed state. Therefore, the relay R and its contact Rb constitute a timer circuit 25.

The vertical ball mill configured as described above operates as follows. At the same time that the slurry supply pump (not shown) is operated to supply the solid material slurry from the inlet 2, the switch 23.
24 is closed. As a result, while a rotational drive acts on the rotating shaft 4, compressed air at a pressure of 1 to 3-/- is supplied from the air inlet 18 to the bottom of the container 1, causing the hard balls that are the grinding medium to float and become dense. Breaks the filling state. As a result, the starting torque of the rotating shaft 4 is reduced, and the rotating shaft 4 can be started reliably and easily. After a predetermined short period of time, the on/off solenoid valve 21 is closed by the timer circuit 25, and the supply of air is stopped.

The slurry supplied to the ball mill started in this way from the inlet 2 at the lower end of the container is stirred by the auxiliary stirring member 17 provided at the lower end of the rotating shaft 4, including the hard balls immediately above the lower end wall 1b of the container. Therefore, the solid material in the slurry that is press-fitted from the lower end of the container is immediately subjected to the crushing action. Therefore, since the crushing action is performed from the bottom to the top of the container, the crushing is carried out efficiently. Furthermore, since there are no hard balls staying at the lower end of the container, the slurry fed from the inlet is not subjected to pressure loss due to the staying hard balls, and is immediately subjected to the crushing action by the stirring hard balls. Therefore, even highly viscous slurries can be processed.

In this way, the solid material and hard balls in the slurry are stirred and reach the separation disk 11 as shown by arrow A. The hard balls and solid material that have reached the separation disk 11 are rotated by the rotation of the separation disk 11 and sent from the separation disk toward the partition wall 6 by centrifugal force. At that time, the sufficiently pulverized solid material is transferred to the separating disk 1 by the slurry feeding pressure from the inlet 2.
1 and the hole in the partition 6 into the outlet chamber 2 through the conical gap 14. However, since the hard balls cannot pass through the gap 14, they are sent from the separation disk 11 toward the partition wall 6 by centrifugal force, and then hit the conical portion 8 of the container and returned downward along the conical surface.

Therefore, a smooth circulating flow of hard balls as shown by arrow A can be formed. At that time, unground solid material that is too large to pass through the gap is returned to the grinding chamber together with the hard balls. In this way, the simple configuration of the partition wall and separation plate allows the crushed solid material to be separated from the hard balls, while the separation screen is not used, so the pa
The UA structure has excellent durability.

In addition, in the embodiment described above, compressed air is supplied to the lower end wall 1.
Although the air is supplied from the air inlet 18 provided in the container 1, the air inlet may be provided at the lower end of the body 1c of the container 1 and the air may be supplied from there. In any case, the air inlet may be provided anywhere on the lower end of the container as long as the tightly packed state of the hard balls can be broken. Moreover, the air introduction 1'' 18 can be provided to be oriented diagonally so that the compressed air is fed in the same direction as the rotating direction of the rotating shaft 4.

In this case, not only can the tightly packed state of the hard balls be broken, but also a force in the same direction as the rotating direction of the rotating shaft can be applied to the hard balls, making starting even easier.

Furthermore, in order to prevent hard balls from falling into the air inlet 18, a hard ball fall prevention screen may be provided. but,
Since this causes a large pressure drop, it is not preferable for instantaneous supply of compressed air.

On the other hand, even if the air inlet 18 is not provided with a screen, any hard balls or the like that enter the air inlet 18 will be instantly pushed out by the compressed air, so there is no problem even if the screen is not provided.

Furthermore, the timer circuit 25 is not limited to the one shown in the figure, which is composed of a delayed activation relay R and its b contact Rb, but may be any other circuit as long as it can open the valve 21 for a predetermined time at the same time as the switch 23 is closed. It may be a timer of the form.

As is clear from the above, according to the present invention, a vertical ball mill can be started easily and reliably.

[Brief explanation of drawings]

The accompanying drawing is a schematic cross-sectional view of a ball mill embodying the present invention. ■... Container, 2... Inlet, 3... Outlet chamber, 4...
・Rotating shaft, 5... Stirring member, 6... Partition wall, 7...
Grinding chamber, 8... Upper opening 16 part of container, 11... Separation disk, 12.13... Wear-resistant metal, 15... Bottle, 16... truncated cone member, 17...・Auxiliary stirring member, 1
7a...Screw, 18...Air inlet, 19...Pipe, 20...'/AL amount adjustment valve, 21...On/off solenoid valve, 22...Compressed air source, 25...・Timer.

Claims (1)

[Claims] (11) A vertically placed cylindrical container having an inlet at the lower end and an outlet at the upper end for receiving the pressurized slurry-formed material; The apparatus comprises: an extending shaft supported rotatably; a plurality of stirring members disposed on the shaft at intervals in the longitudinal direction thereof; and a drive device for rotating the rotating shaft; When starting a vertical ball mill configured to grind the material to be processed using a grinding medium placed in a container, compressed air is supplied from the lower end of the container to ensure that the grinding medium inside is tightly packed. A method for starting a vertical ball mill, characterized in that the starting torque of the rotating shaft is reduced by collapsing the rotary shaft. (2) The compressed air to be supplied is 1 to 3 kg/Cl1.
1. A method for starting a vertical ball mill according to claim 1, wherein the pressure is 1. (3) A cylindrical container placed vertically with an inlet at the lower end and an outlet at the upper end for receiving the pressurized slurry processed material, and a cylindrical container extending in the longitudinal direction of the container and rotating. The apparatus includes a freely supported shaft, a plurality of stirring members disposed on the shaft at intervals in the longitudinal direction, and a drive device for rotating the rotating shaft, and is placed in the container. In the vertical ball mill, the object to be processed is ground by a grinding medium, an air inlet formed at the lower end of the container, and an air inlet connected between the air inlet and a compressed air source. A vertical ball mill comprising: an on-off solenoid valve; and a timer circuit that opens the on-off solenoid valve simultaneously with closing of a switch of a drive motor for the rotating shaft and closes it after a predetermined period of time. (4) The vertical ball mill according to claim 3, wherein the air inlet is provided on the lower end wall of the container. (5) The vertical whole mill according to claim 3, wherein the air inlet is provided at the lower end of the body of the container.