JPS6259995B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a classification method for sizing water-absorbing granules such as coal and ore to improve various processing operations. In general, coal is contaminated with impurities during mining, and since the coal itself is a collection of materials with different ash content, particle size, and other coal properties, it must be sorted through coal preparation, and this coal preparation process involves pulverization. It consists of processing steps such as sizing, gravity sorting, flotation, etc. In each step, the sieving operation plays an important role for grain size adjustment. However, conventionally, coking coal is often piled up in open yards in yards, and when handled, it gets wet when it rains and dries out when it is sunny, resulting in moisture fluctuations (6-13%) in the coking coal that is put into the cutting tank each time. Significant. In addition, the adhering moisture, stickiness, and particle size distribution of coal vary significantly depending on the name of the coal, and in conventional sieving equipment, the sieving operation is affected by the adhering substances to the sieve plate such as the sieve screen, and the clogging rate fluctuates significantly. For example, substances to be handled may adhere to the strands of the sieve screen and gradually grow, making the strands thicker, i.e.
Initially, the mesh opening S decreased as the usage time elapsed.
>S ₁ >S ₂ and finally S _o =0, resulting in a clogging phenomenon and no longer functioning as a sieve. In particular, the deposits that grow between the strands are soft and grow from any part of the wire when they come into contact with the wire, and the vibration of a vibrating sieve does not have the strength to shake them off, so it is difficult to remove them even when scrubbed with a debris brush, and they harden when dry. This will interfere with the sieving work. These obstacles have made it difficult to actually classify and size the coal. Furthermore, even if a sieve equipped with a cleaner to prevent clogging is used, the upper limit of the sieve's classification ability varies depending on the type of coal or moisture fluctuations, so if the physical properties are poor, the classification efficiency = under-sieve recovery rate, i.e. (amount of under-sieve material). /The amount of particles below the classification point decreased, and the desired classification accuracy could not be obtained.The present invention appropriately prevents the clogging phenomenon and adhesion that occur on the mesh surface. , except for the drawbacks of the conventional ones, it keeps the screen surface clean at all times, effectively prevents the drop in classification efficiency, allows efficient sieving work, and improves the ease of wet coal sieving and the degree of grinding and adjustment. It is an object of the present invention to provide a coal classification system that is favorable and can greatly improve operational efficiency.The present invention is a coal pulverizing and granulating equipment for coke production that A primary sieve with a cutout amount (feed amount) measuring device is arranged, and in front of and behind the primary sieve, there is a material measuring device on the primary sieve, a crusher, a crushed material measuring device, a secondary sieve, and a secondary sieve. The sieved product of the secondary sieve has a path to be re-injected into the crusher, and each of the above-mentioned devices is connected by a head or a conveying device and is operated in coordination with the coal. Supply (cutting amount): Q ₁ [Kg] Amount of product on the sieve of the primary sieve: qu ₁ [Kg] Amount of product under the sieve of the primary sieve: ql ₁ [Kg] Amount of supply to the secondary sieve: Q ₂ [Kg] Amount of product on the sieve of the secondary sieve: qu ₂ [Kg] Amount of product under the sieve of the secondary sieve: ql ₂ [Kg] Classification point of feed rate to the primary sieve: Pt ₁ mm Particle distribution ratio of d>Pt ₁ in supplied coal:
α ₁ % Particle distribution ratio of d≦Pt ₁ in coal fed to the primary sieve:
β ₁ % Classification point of coal fed to secondary sieve: Pt ₂ mm Particle distribution ratio of d>Pt ₂ of coal fed to secondary sieve:
α ₂ % Particle distribution ratio of d≦Pt ₂ in the coal fed to the secondary sieve:
β ₂ % Classification efficiency...When constants C ₁ and C ₂ , Q ₁ ×β ₁ ×C ₁ ≦ql ₁ →Q ₁ ≦ql ₁ /β ₁ ×C ₁ Q ₂ ×β ₂ ×C ₂ ≦ql ₂ →The cutting amount is controlled so that Q ₂ ≦ql ₂ /β ₂ ×C ₂ , and the above 1
During the sieving process of the secondary sieve, the coal is placed on a vibrating vertical line network of a vertical lattice-like screen in which vertical lines without horizontal lines are arranged in parallel, so that it can move freely in the flow direction and also move in the width direction. It has a contact body that can be arranged to peel off and remove substances attached to the vertical wire mesh in each sieving process by changing the vibration mode of the vertical wire, and the movement of the contact body can be used to move the material through the mesh sieve of the sieved product. This is a method for pulverizing and granulating coal, which is characterized by classification using a sieve equipped with a mechanism equipped with a cleaner that performs continuous control based on the recovery rate of coal. The present invention will be described with reference to the drawings in an embodiment. Raw coal is fed from a raw material yard A into a storage tank C by a conveyance device B, and the amount of coal supplied is dispersed and distributed by a cutting device D with a constant control mechanism, for example, a belt conveyor. (Cutting amount) Q ₁ is direct or conveyance device E with measuring device
A fixed amount is supplied to the primary sieve _F1 , where it is sieved and sorted. A crusher G is installed after or before this primary sieve _F1 .
For example, crushers, breakers, etc., and conveying devices H, I, and J with measuring instruments are attached and provided as necessary, and are connected to the secondary sieve _F2 . The sieved product obtained by the secondary sieve F ₂ is transferred to a conveying device K with a weighing device in quantity qu ₂
is measured, circulated and re-injected into the pulverizer G, and the amounts ql ₁ and ql ₂ of the unsifted products from the primary sieve F ₁ and secondary sieve F ₂ are transferred to the weighing conveyor I, Each is measured in L and becomes a product. Then, in response to fluctuations in the product amounts ql ₁ and ql ₂ above and below the sieve, the coal supply amount Q ₁ or the secondary sieve F ₂
The supply amount _Q2 or both are automatically controlled. For example, if we classify Pt=6mm, coking coal
If the particle size distribution in 100Kg is Pt>dmm:80Kg Pt≦dmm:20Kg, if the sieve classifies with 100% efficiency,

[Table] becomes. By the way, if the moisture classification performance fluctuation factors change at this time, the fluctuations will occur as shown in Table 1 even when 100 kg is supplied.

[Table] ↓ ↓ ↓
50 45 40
In the case of (c), the recovery rate η under the screen is η = 40/80 = 50%. This means that 50% of the original particles under the mesh flowed onto the mesh. Reducing the feed rate improves the undernet recovery rate. In other words, there is a limit to the amount that can pass per unit area of the net for each name, and if a load beyond that is applied, all of it will flow out on the net, so in such a case, the particle size distribution of coking coal will be different for each name. Since the current classification efficiency can be continuously grasped by measuring the amount of product above and below the sieve, this measurement can be used to compare the classification efficiency with the desired classification efficiency and identify any decrease in efficiency. In this case, the amount fed to the sieve is controlled to be lowered. Therefore, if the distribution of particles below the classification point is 80% in a certain name, and the required value of the under-sieve recovery rate is 70%, the operation will be such that the amount of feed x 0.8 x 0.7 ≦ the amount of under-sieve product. Therefore, it is only necessary to change the supply amount. In these control methods, the operating state of _{the supply device related to the coal supply amount Q1 or the supply amount Q2 to the} secondary sieve F2, such as the cutting device D, the conveying devices E, H, J, or the crusher G, is changed. Therefore, the driving source may be operated intermittently or at variable speed, the hopper or the member that adjusts the flow rate may be adjusted, and the vibration state of the primary sieve F ₁ and the secondary sieve F ₂ or the adhesion of substances on the sieve plate may be adjusted. It is preferable to set the movement operation of the removal member to be variably controlled. In these cases, the vibrating sieves used as the primary sieve F ₁ and the secondary sieve F ₂ are placed on the upper surface of the vibrating sieve having a multi-stage mesh, are movably supported in contact with the mesh surface, and are movably supported. Using a vibrating sieve equipped with a removal mechanism that removes the objects adhering to the screen surface by applying a contact force to the screen surface with a contacting body,
Preferably, the removal mechanism is moved by a mechanical driving force, and the moving area covers the entire effective area of the sieve. For example, the vibrating sieve main body 1 is equipped with a vertical wire mesh 2 such as a wire mesh screen, and a spring 1 is attached to the support device frame so as to be vibrated by a vibration motor 3.
It is supported by 1. That is, the vibrating sieve main body 1 is elastically suspended from a frame 20 by a hanging fitting 21 and a spring 11, and is vibrated by a motor 3 or an oscillator such as an electromagnetic vibrator. 5
The vertical line network 2, 2...... of vertical lines of
Moreover, each vertical line network is provided at an angle. Each vertical line network has a large number of vertical lines extending parallel to the inclination direction to form a network, and there are no or very few horizontal lines. Further, the intervals between the vertical lines are arranged narrower from the upper vertical line network to the lower level. The oscillator is 2
The necessary vibration conditions can be provided by reversing the direction of rotation during assembly. The striations may be formed by arranging rigid narrow bars in addition to vertical striations. During operation, if coal is supplied to the dispersion plate 22 while the vibrating sieve main body 1 is vibrated by an oscillator, the vibration will cause it to advance downward and be almost uniformly dispersed in the width direction. Particles falling onto the wire net 2 and moving toward the exit side due to vibration and inclination, particles smaller than the spacing between the vertical wires fall and fall onto the next lower vertical wire net 2, and this process continues. It is repeatedly classified into those that have passed through the vertical line network 2 at the bottom and those that have fallen and those that have not fallen. On each of the vertical wire networks 2, a removal member, for example a contact member 4, for peeling off and removing substances attached to the vertical wire network is arranged so as to move over the entire effective area of the vertical wire network. In this embodiment, the contact body 4 is attached to the rod 10 of the fluid cylinder 5, and is reciprocated and linearly moved in the axial direction by pneumatic or hydraulic operation. Mechanisms can also be used. The cylinder 5 is supported by a pivot bearing mechanism 6 so as to be able to swing relative to the pivot. The contact body 4 may be subjected to a load due to weight imbalance, or it may be held close to the contact body 4 without contacting it. The transverse feed frame supporting the cylinder 5 is configured to be given reciprocating linear motion in the transverse direction, that is, in the width direction of the vertical wire network, by driving the feed screw 7 by a motor 14 and a transmission device 13. ing. In this case, the relationship between the vertical line network and the contact body 4 is as shown in FIG. 7, where the contact body 4 moves in the X direction. At this time, the net body is vibrating and the amplitude is V. Figure 8 shows the temporal change in the position of the mesh surface due to vibration and the locus of the contacting body. When the contacting body 4 moves along the flow direction of coal and its axial movement speed is x, the distance between the strokes s and Time required to move t
is t=s/x. In this case, by keeping the lateral movement speed u such that u≦t/l, the contacting body could be brought into contact with the entire surface of the net, but the sieve of the vertical screen could be scraped over the entire effective area. It is possible to remove deposits very effectively and keep the net clean. Especially contact body 4
In the area where the filament contacts, the filament will bend locally, creating a step between it and the part that does not make contact.
The ability to remove clogging substances can be greatly improved. The use of the above-mentioned sieving device has the advantage of being able to classify coal, which was difficult to sieve conventionally, and since this device has multiple stages, the sifting point can be changed by switching the damper installed on the discharge side. There is also the advantage of being able to change in a short time. Furthermore, comparing the distribution of moisture in coal between lump coal and pulverized coal, the surface area of equal weight of lump coal a cm ² pulverized coal b
cm ² , a<b, and there is a positive correlation with the moisture surface area, so pulverized charcoal has a higher moisture value. When such coal is classified, the lump coal, which is a sieved product, has a lower moisture content than the raw coal, so when it is crushed, it has the advantage of being less likely to stick to the striker and casing. Therefore, since the moisture content of the crushed coal is lowered, this has the effect of further reducing adhesion to the sieve when classifying it, and the process of classifying - crushing - classifying - crushing is repeated for coal that is difficult to sieve. It can provide an extremely effective function in regulating carbon quality. In the figure, 5' is a balance weight, 8 is a bearing, 9 is a column, 13 is a winding transmission or gear transmission, 14 is a motor, 15 is a charging hopper, 16 is a discharge chute, 17 is a guide rail, 18 is a cover, 19 20' is a moving collar, 24 is a roller, and 25 is a guide rail. Although the cylinders 5 are provided for each of the contact bodies 4 provided for each vertical line network 2, a plurality of contact bodies 4 can be reciprocated by one cylinder 5 by interposing a connecting rod. In addition, on the top surface of the vibrating sieve, vertical line mesh ball-shaped hitting bodies are arranged in the longitudinal direction like beads and placed along the moving piece, and the two sides of the vertical line mesh vibrating in a reactionary manner are repeatedly struck and brought into contact with each other. It is also possible to make the attached material fall off, or to pull up the striker with a string-like body and allow it to fall intermittently under its own weight, thereby causing the attached material to fall off. The vibrating sieve main body 1 is vibrated by a vibrating motor 3, and loose materials such as coal, which are fed through a dispersion plate 22, fall onto the vertical wire mesh 2, and particles smaller than the screen spacing are successively deposited onto the vertical wire mesh 2 below. The amount of coal supplied to each sieving process is adjusted depending on the classification efficiency, and as the vertical wire network 2 vibrates, the cylinder 5 The drive device 1 is actuated to reciprocate the contact body 4 via the rod 10 and repeatedly move in the longitudinal direction on the vertical wire network 2, while also moving the drive device 1 in the width direction of the vertical wire network 2.
4, the feed screw shaft 7 is rotated to move the feed frame 12, and the contact body 4 is moved over the entire effective area of the vertical wire network 2 to remove deposits that are attached to or growing on the vertical wire network 2. In combination with the vibration action of the present invention, it is possible to effectively prevent clogging of the peeling or brushing off vertical wire mesh 2, and to maintain the surface of the vertical wire mesh clean, thereby significantly increasing classification efficiency. In the sieving process, the present invention has an effect of knocking off adhered particles by the striking force caused by the vibration of the vertical wire mesh, a scraping effect of the adhered particles by the movement of the contact body, and an action of removing the deposits by the displacement between the strands of the vertical wire mesh. This makes it possible to accurately remove the deposits that occur on the vertical wire mesh surface, and the vibrating screen can be kept clean at all times, which prevents clogging of the vibrating sieve and a decrease in classification efficiency due to adhesion, and improves the sizing process. The maintenance and security of the sieve is simple, and the work efficiency is greatly improved, making it easier to sieve wet coal.Moreover, the entire effective sieve surface is scraped off by time changes in the position of the screen surface due to vibrations and changes in the movement of the contacting body. Since the removal of deposits on the wire network is carried out efficiently and the control is based on the recovery rate, it is possible to operate quickly in response to changes in moisture content, and it is possible to treat coal effectively for coke production, as well as reduce dust generation. It has the advantage of being sufficient to comply with noise regulations.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is an explanatory diagram of the system, FIG. 2 is a side view of the sieving device, FIG. 3 is a front view, FIG. 4 is a partially enlarged side view, and FIG. is the fourth
FIG. 6 is a partial perspective view, and FIGS. 7 and 8 are explanatory views of the operating state. A... Raw material yard, B... Conveying device, C... Storage tank, D... Cutting device, E, H, I, J, K, L
...conveying device, G ... crusher, F ₁ ... primary sieve,
F ₂ ... Secondary sieve, 1 ... Vibrating sieve main body, 2 ...
Vertical line network, 3... Vibration motor, 4... Contact body, 5...
...Fluid cylinder, 6...Swivel core bearing mechanism, 7...
Feed screw, 10...Rod, 11...Spring, 12
...Feeding frame, 13...Transmission device, 14...
Motor, 20...Frame, 21...Hanging fittings.

Claims (1)

[Claims] 1 A coke manufacturing facility includes a step of crushing, transporting, and sifting coal, and in this sifting step, a vertical lattice screen in which vertical stripes without horizontal lines are arranged in parallel. The contacting body is placed on the vibrating vertical wire network so as to be movable in the flow direction of the coal, and is also movable in the width direction, so that the contact body is moved to peel off and remove substances attached to the vertical wire network in each sieving process. Continuous control is performed based on the sieve product recovery rate of the sieved product, and each sieving process is carried out at each classification efficiency based on the ratio of the amount of cleaned coal sieved in the sieving process to the amount of particles below the classification point. Qf×β×C≦ql……Qf≦ql/β×C However, Qf…cutting amount [Kg] ql…amount of material under the sieve [Kg] Pt…coal supplied to the sieve Classification point [mm] α...Particle distribution ratio of d>Pt in the coal fed to the sieve [%] β...Particle distribution ratio of d≦Pt in the coal fed to the sieve [%] C...Classification efficiency constant A coal classification method characterized by adjusting as follows. 2. The supply amount control measures the amount of product on or under the sieve screen of the sieve plate of the primary sieve screen or secondary sieve screen in the sieving process performed using a vibrating sieve in which a plurality of sieve plates are arranged at an angle. The classification method according to claim 1, wherein the amount fed to the sieve is increased or decreased so as to maintain a predetermined classification efficiency. 3. The classification method according to claim 2, wherein the pulverizing step involves recycling and reintroducing the sieve material below the secondary sieve into at least the preceding pulverizer to pulverize it.