JPH0275356A - Hammer mill - Google Patents

Abstract

PURPOSE:To finely pulverize a raw material by forming a raw material filler and an air intake to a casing on one side thereof and providing crushing and pulverizing hammers to the rotary shaft at the center of the casing to form a pulverizing zone. CONSTITUTION:Feed (a) is thrown in a casing 10 in a sucked state through a throwing cylinder 11 by a feeder 30 and beaten by hammers 18, 22, 25 in zones A, B, C to be pulverized and moved through the zones A, B, C by an air stream while gradually pulverized finely and reaches a receiving part D as a product (b) while coarse particles are removed by screens 23, 27. The coarse particles reaching the fine pulverizing zone C is returned to the crushing zone A through a duct 29 by the recirculation stream in the duct 29 to be again pulverized. By this method, the load of a suction fan can be reduced.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a hammer mill for fine grinding.

[Prior Art] Conventionally, as a hammer mill for fine pulverization, there is an impact type horizontal fan function-equipped hammer mill shown in FIG. So, that is,
A plate-shaped crushing hammer 3, a U-shaped crushing hammer 4, and a similarly U-shaped fine crushing hammer 5 are provided in order along the axial direction of the rotating shaft 2 in the casing 1 (each hammer 3 (For the shape of .4.5, refer to the examples below), casing 1
A coarse crushing zone A, a crushing zone B, and a fine crushing zone C are formed inside the casing 1, and the raw material a is introduced from one end of the casing 1, and air is taken in by a fan 6 from the other end.

This device generates an air flow in the casing 1 by intake air, gradually breaks the raw material into pieces with each hammer 3.4.5, and conveys the raw material by the air flow,
The raw material with the desired particle size is taken out to the product storage section through the screen 7, and the product soot is conveyed to the next process by the conveyor 8, and the product soot mixed in the intake air of the fan 6 is captured by the back filter 9. and send it to conveyor 8.

[Problem to be solved by the invention]

By the way, in this conventional hammer mill, raw material a
is not sufficiently coarsely crushed and pulverized, and reaches the fine pulverization zone C, where it remains and the screen 7 is clogged.
or grinding burn due to long-term residence. Further, if the raw material a remains, the rotational resistance of the hammer 5 increases, leading to an overload condition, which causes various problems.

For this reason, the above-mentioned conventional technology cannot be used for final grinding of finely ground feed in the feed industry, and the process is carried out using a dismembrator (run).However, this dismembrator is compared to a hammer mill in terms of grinding efficiency. It is inferior to
On the other hand, there is a problem in that rough grinding is not possible.

With the above points in mind, it is an object of the present invention to provide a hammer mill that can perform fine pulverization without causing overload or pulverization burn.

[Means to solve the problem]

In order to solve the above problems, in the present invention, a raw material input port and an air intake port are formed in an example of a casing, a rotating shaft is provided in the center of the casing, and the rotating shaft is connected from the one side to the other side. A coarse crushing hammer and a crushing hammer are sequentially provided in the casing to form a coarse crushing zone and a crushing zone, and the outer casing of the crushing zone is expanded over the entire circumference, and the rotating shaft is inserted into the crushing zone. A pulverization hammer is installed through a support plate fixed to the pulverization zone to form a pulverization zone.
A first screen for passing pulverized particles is provided between this pulverization zone and the pulverization zone all around the periphery, a circulation duct communicating with the raw material input port is opened in the upper part of the pulverization zone, and a circulation duct is opened in the lower part of the pulverization zone. This is a structure in which a product storage section in an air intake state is arranged in series through a second screen for passing through the fine particles.

[Effect]

In a hammer mill configured in this way, first, when the rotating shaft is rotated, the hammers in each zone also rotate, creating a flow of air in the radial direction. At this time, since the pulverization zone and the pulverization zone each have an air outflow section on the outer periphery by a screen and duct opening, the flow in the radial direction is
The flow crosses each zone, and this flow is in the same direction as the flow due to the intake air, thus promoting airflow within the casing. The air flow also causes the coarse crushing zone to have a lower pressure than the fine crushing zone, causing air to circulate through the duct.

In this state, when the raw material is introduced into the casing from the input port, the raw material is pounded and crushed by each hammer in each zone, gradually becoming fine particles, and is carried by the air flow. It moves through each zone, and coarse particles are removed by the first and second screens before reaching the product storage section. At this time, the coarse particles that have reached the pulverization zone are captured by the second screen and try to accumulate on its surface, but due to the centrifugal force of the hammer and the circulating flow of the duct, they are sent back to the pulverization zone through the duct. and then re-ground.

On the other hand, the fine powder passes through the second screen and is hardly recycled.

〔Example〕

As shown in FIGS. 2 and 3, a feeding cylinder 11 for feed (raw material) a is provided on one side of the casing 10, and
A rotating shaft 12 is provided at the center of the inside. The casing 10 consists of a cylindrical part 10a forming a coarse crushing zone A, which will be described later, and a square box-shaped part 10b connected to the part 10a. A pulverization zone B, a pulverization zone C, and a product storage section, which will be described later, are configured. Feeding feed a into the feeding cylinder 11 is as follows:
This is done via an on-off valve such as a rotary pulp or butterfly damper, and the charging cylinder 11 is formed with an air intake port 13 that allows the amount of ventilation to be adjusted. This air intake 1
The opening degree of No. 3 is determined by the amount of air circulation described below.

A rotating disk 14 is fixed to the tip of the rotating shaft 12, and the air flow rate from the injection tube 11 into the casing 10 is determined by the gap t between the rotating disk 14 and the casing 10. That is, the diameter of the rotating disk 14 is increased (the airflow becomes faster).A partition/support plate 15 for the coarse crushing zone A and the crushing zone B is fixed to the middle of the casing 10 of the zero rotation shaft 12. A partition plate 1 is provided between this support plate 15 and the rotating disk 14.
6 are provided at equal intervals, and between them, strip-shaped coarse crushing hammers 18 are rotatably attached at four equal positions in the circumferential direction through pins 17 to constitute a coarse crushing zone A. When rotated, A crushing hammer 18 flies out toward the casing 10 side by centrifugal force and crushes the fed feed a. At the bottom of the coarse crushing zone A, a pit P for separating heavy objects such as metals, metals, stones, etc. is formed.

A support plate 19 extending close to the inner surface of the box-shaped portion 10b is fixed to the rear end of the rotating shaft 12 inside the casing 10, and two partition plates 20 are provided between the support plate 19 and the support plate 15. In the meantime, U-shaped crushing hammers 22 are rotatably attached to four equal positions in the opening direction to form a crushing zone B. When rotated, the crushing hammers 22 protrude outward and coarsely Crushed feed a from crushing zone A
to crush. Note that the crushing hammers 22 are provided side by side on the same pin 21 as shown in FIG.

Moreover, this crushing zone B has a width (
Since the hammers 18 and 22 have a larger diameter (in the direction of the rotation axis) and a larger outer diameter (screen diameter, which will be described later), the blowing effect of the hammers 18 and 22 is higher in the latter case.

For example, it is set to about 1.5 times.

A first screen 23 is stretched around the outer periphery of the grinding zone B, and the hole diameter of this screen 23 is approximately twice the finished particle diameter. However, if the hole diameter does not fall within the crushing particle size range of the crushing hammer 22, it should be doubled or more so that it falls within the range.

In the casing 10 outside the screen 23, pins 24 fixed to the support plate 1908 are located,
As shown in FIG. 5, U-shaped pulverization hammers 25 are attached to each pin 24 in a staggered manner via a partition annular plate 26 and a support ring 26' to form a pulverization zone C. ing. A second screen 27 is stretched around the outer periphery of this crushing zone C, and the inside of the casing 10 outside the screen 27 serves as a product storage section. The hole diameter of the screen 27 is determined by the finished particle size (product particle size), and is usually 10 to 20% larger than the finished particle size.

An opening 28 is formed in the screen 27, and a circulation duct 29 is inserted through this opening 28. It is connected to J11. The diameter of this duct 29 is determined to be approximately one-third of the amount of air flowing within the casing 10. If the amount of circulation is large (this will reduce the amount of exhaust air generated by the fan described later, and the load on the exhaust treatment equipment will also be reduced), feed (raw material) a that can ignore obstacles (temperature, moisture, etc.) due to the circulation of crushing heat. In this case, increase the amount of circulation.

This embodiment is constructed as described above, and as shown in FIG. 1, when the feed a is fed into the casing 10 through the feeding tube 11 by the feeder 30 while being sucked in by the fan F, The feed a is for each zone A,
In B and C, the first and second Coarse particles are removed by screens 23 and 27 to form a product and reach the storage section.

During this crushing action, the coarse particles that have reached the fine crushing zone C are captured by the second screen 27 and try to accumulate on its surface, but due to the centrifugal force from the hammer 25 and the circulation flow of the duct 29 (for example, 15m8) As a result, it is sent back to the crushing zone A via the duct 29 and re-pulverized. That is,
- There is no accumulation in places, so there is no overload condition.
There is no risk of crushing burnt feed a, which is re-pulverized and pulverized.

The products that have reached the product storage section are conveyed to the next process by a conveyor 31. In addition, air taken in by the fan F is exhausted through a bag filter 32 , and product particles in the air are caught in the bag filter 32 and sent to the conveyor 31 .

Note that if the hole diameter of the second screen 27 is appropriately selected,
The product can also be of any diameter. In other words, from rough grinding to fine grinding 1r? Wear.

〔Effect of the invention〕

This invention is constructed as described above, and the coarse particles are circulated and re-pulverized, so that fine pulverization can be performed without overloading or causing pulverization burn.

In addition, since the fine grinding zone was provided on the outer periphery of the grinding zone,
The hammer in that zone can promote airflow and reduce the load on the intake fan.

[Brief explanation of the drawing]

FIG. 1 is a schematic operational diagram of an embodiment of a hammer mill according to the present invention, FIG. 2 is a cutaway front view of the same embodiment, FIG. 3 is a left side view of FIG. 2, and FIG. FIG. 5 is a perspective view of the main part of the pulverization zone shown in FIG. 2, FIG. 5 is a perspective view of the main part of the pulverization zone of FIG. 2, and FIG. 10...Casing, 11...Injection tube, 12...Rotating shaft, 13...Air intake port, 14...Rotating disk , 18...
...Crushing hammer, 22...Crushing hammer, 23...First screen, 25...Fine crushing hammer, 27...Second screen, 29 ...Circulation duct, A...Crushing zone, B...Crushing zone, D. River...Product storage section, F...Fan, a. ...Feed (raw materials), b...Products. Patent applicant Amsec Co., Ltd. Agent Kama 1) Text - Figure 1 Figure 2 Feed a Figure 3 P loa Figure 4 Figure 5

Claims (1)

[Claims] (1) A raw material inlet and an air intake are formed on one side of the casing, a rotating shaft is provided in the center of the casing, and a crushing hammer and a crushing hammer are installed on this rotating shaft from one side to the other. A coarse crushing zone and a crushing zone are formed in the casing, and the outer casing of the crushing zone is expanded over the entire circumference. A hammer is provided to form a pulverization zone, and a first screen for passing pulverized particles is provided around the entire circumference between this pulverization zone and the pulverization zone, and a circulation system is provided above the pulverization zone that communicates with the raw material input port. A hammer mill in which a duct is opened and a product storage section in an intake state is connected to the lower part of the pulverization zone through a second screen for passing pulverized particles.