Reformation of Feeding Device of Deep Cone Thickener

Modern tailings water systems generally use closed loops. Thickeners are the key equipment of the tailings water treatment system. The concentration effect of the thickeners will directly affect the operation of the entire concentrator. The structure of the original feeding device mainly includes The defoaming barrel, the feed pipe, the upper straight section of the stabilizing barrel, the upper cone section of the stabilizing barrel, the middle straight section of the stabilizing barrel, the sieve plate and the lower cone section of the hidden barrel are composed of; The overflow weir of the thickener.

The structure of the defoaming cylinder is too simple, the mixing effect of the slurry and flocculant in the defoaming cylinder is poor, and the settling effect of the flocculant is poor; the straight section between the defoaming cylinder and the stabilizing barrel will be connected by a feed pipe, and the slurry will enter the stabilizer. The feed kinetic energy of the straight section between the barrels is large, which affects the sedimentation effect of the thickener, and the concentration efficiency is low; the upper end of the straight section on the stabilizer barrel is higher than the thickener overflow weir, and the clarified water at the upper part of the thickener cannot enter the original feed Inside the device, the flocs have not undergone the process of dilution, and the sedimentation speed of the flocs has slowed down.

The static flow stabilizer is composed of an inlet pipe, a cylinder, a baffle plate, a uniform cloth and a plate outlet pipe. After the flocculant is mixed with the slurry, the direction of the fluid is changed through the baffle plate and the uniform plate to make the flocculant and the slurry full The mixing of the kinetic energy of the mineral pulp at the same time can improve the flocculation effect.

The static steady flow mixer is equipped with two discharge pipes, which can further reduce the kinetic energy of the slurry.

The spiral material stabilization device is composed of an overflow cylinder, a cylinder, a spiral blade, a cloth plate, an inner cone and a lower cone; the upper end of the overflow cylinder is lower than the overflow weir of the thickener, and there are countless numbers on the upper part of the overflow cylinder A "rectangular" slot; the clarified water on the upper part of the thickener will flow through the upper end of the overflow cylinder and the "rectangular" slot into the spiral stabilizer, which realizes the self-dilution of the slurry, and the flocs are diluted to speed up the continuation The settlement rate.

The spiral blades on the inner wall of the spiral material stabilization device are distributed with multiple slots; the slurry entering the cylinder along the spiral blades gradually rises by its own kinetic energy, and a part of the slurry continues to rise along the spiral blades; The slurry flowing to the next spiral blade at the slot and the next spiral blade collides and mineralizes; the remaining part of the slurry flows to the center of the middle cylinder, and further collides and mineralizes with the falling slurry, making the flocculant and the slurry Fully mix to improve the flocculation effect.

Because the concentration of the slurry inside the spiral stabilizer is higher than the slurry injected onto the cone, part of the slurry passes through the small holes on the cone and collides with the spirally rising slurry in countercurrent; while reducing the kinetic energy of the slurry, it further improves Concentrated effect.

After the improvement, it has been running very well so far; the use of static steady flow mixer has improved the flocculant settlement effect of the flocculant; the kinetic energy of the slurry input is reduced through two-person feed pipes, and the purpose of mutual dilution is achieved; through the spiral The spiral blade in the material stabilization device consumes the kinetic energy of the slurry; the upper end of the spiral material stabilization device is lower than the overflow weir of the thickener, which realizes the self-dilution of the slurry and accelerates the sedimentation speed of the slurry; the final concentration of the overflow water of the thickener is small to ensure In order to improve the quality of the circulating water in the system, Xining and its consumption will be saved, reducing operating costs. After the transformation, it can be widely used in large-scale concentrators, and can replace ordinary rake thickeners to process mine tailings slurry.

A worthy headbox of dual-pressure zone thickener

 The double-pressure zone thickener is mainly used for the washing and concentration of the slurry in the waste paper deinking and reducing treatment system. The machine is mainly composed of active rollers, driven rollers, and endlessly woven filters and flow boxes running around two rollers. , Discharge screw conveyor and other components. The slurry passes through the headbox, which is dewatered by the squeezing action between the filter screen and the active roller in the nip between the filter screen and the active roller. The active roller is engraved with deep grooves, which can obtain a high nip pressure, so that the slurry is concentrated on the inner surface of the mesh into a form of slurry strips. These strips are kept on the filter screen. When the slurry enters the filter In the nip between the net and the movable roller, it will be further dehydrated and then separated from the net surface, falling onto the roller surface and being scraped off and discharged by the scraper. The concentration of the slurry discharged by the machine is constant, and the discharged slurry will be transported away by a screw conveyor, and the removed white water containing ink particles and fillers will be discharged from the bottom of the white water tray.

The double-nip thickener is favored by users because of its good performance, but with the continuous expansion of the wide screen of the filter screen, major problems have become more and more serious; one is the thickness of the slurry layer on the entire web is inconsistent, and the slurry concentration is uneven; the other is The filter is easy to run off, causing the filter to tear. But this will bring great economic losses to the enterprise.

For the problems of the double-pressure thickener, the reasons are as follows:

1. At first, I suspected that the quality of the filter was not good enough; after consulting with the manufacturer of the filter, it was required to strictly follow the technical requirements of the filter. After many experiments, it was proved that the tearing of the filter was not caused by the quality of the filter itself.

2. The sensitivity of the deviation adjustment mechanism is not enough, and the deviation signal cannot be transmitted in time, which will cause the movement of the deviation adjustment motor to lag. By replacing several sets of new control modules, the test is carried out quickly, the deviation adjustment signal is transmitted in time, and the deviation adjustment mechanism moves quickly. The tearing of the filter has little to do with this item.

3. If the machining error of the worm and connecting rod of the two worm gear boxes is too large, the transmission will not be in place and the deviation can not be corrected. Through machining a higher precision worm and connecting rod, the phenomenon of deviation of the filter screen will also occur.

4. If the coaxiality of the two transmission rollers processing fails to meet the requirements or the installation axes of the two rollers are not parallel, vibration will occur, which will cause the filter screen to jump and cause deviation. Re-adjusting the installation accuracy of the two rollers, the effect is still not satisfactory.

It may also be the problem of the headbox. The function of the headbox (1) is that the slurry that is sprayed is evenly distributed along the horizontal direction of the active roller; it effectively disperses the fibers and improves the uniformity of the slurry layer; the spraying is stable. If the pulp output from the headbox is not uniform, the pulp concentration will be uneven, and the filter screen will run off and cause tearing. Therefore, improving the design of the headbox structure is a key issue to solve the problem of the dual-pressure thickener.

After the improvement of the headbox, there are mainly several aspects:

1. In order to ensure that the pressure of the slurry flowing through each section along the way is the same, the sizing main pipe is designed into a square cone pipe with a smaller and smaller cross-sectional area.

2. In order to facilitate the hole arrangement and keep the direction of the slurry flow at the end of the main pipe unchanged, a rectangular tapered pipe of equal width will be used, and the "height ratio" at the entrance is 1:2~3.

3. The main pipe should facilitate the incoming slurry to change the direction of slurry flow. A transition pipe is set between the main pipe and the slurry inlet pipe, and the circular slurry inlet pipe is gradually changed into a rectangular main pipe. The final wall of the slurry inlet pipe and the square cone pipe should be on a horizontal line.

4. Equipped with a return pipe. The function of setting backflow is mainly to ensure the stability of the slurry flow pressure in the branch pipe and the uniform distribution of the slurry. At the same time, there is no dead corner at the end of the cone pipe to prevent the slurry clusters from gathering, expel air bubbles, and play a cleaning role.

5. The main pipe is made of stainless steel, and the inner wall is processed smoothly, without grout or rust. In order to ensure that the main pipe is not deformed, reinforcing ribs are arranged on both sides of the outer wall of the main pipe to make the main pipe have sufficient rigidity.

6. Ensure that the center of gravity of the headbox is on a straight line, which is more conducive to the stability of the headbox.

After the improved design of the headbox, the thickness of the slurry layer on the entire web is uniform, the slurry concentration is basically stable, the service life of the filter is greatly improved, the maintenance cycle of the equipment is reduced, the cost is correspondingly reduced, and the production efficiency of the enterprise is improved.

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How to use inclined plate thickener for tailings dry discharge

 Tailings treatment is an important part of mine production. Concentration in dry tailings discharge is an important link in achieving dry stacking. It not only directly affects the processing capacity of filter equipment, but also affects the resistance of filter cakes. The particle is resistive to the filter cake, so according to the characteristics of iron tailings, there is a new type of thickener.

The flow of tailings slurry in the thickener is ideally slow. As soon as the solid particles leave the flow layer, they will be considered as sediment. This model is also called shallow sedimentation. The sedimentation occurs in the void between the inclined plates. Within the cavity, but due to the small spacing between the inclined plates, it creates favorable conditions for the formation of laminar flow. The clarified overflow water moves upward along the inclined plate space, and the solid particles settle between the two plates, and only need to settle to a small distance to fall on the plate, and then slide down the inclined plate to the compression port for compression and dehydration , The final height will be discharged from the bottom discharge port. According to the difference between the feeding direction and the sedimentation direction of solid particles in the inclined plate thickener, it can be divided into upward flow and downward flow. Three types of lateral flow.

(1) Upward flow means that tailings slurry is fed from the lower part, the sediment is discharged from the lower part, and the overflow is discharged from the upper part;

(2) Downward flow means that tailings slurry is fed from the upper part, the sediment is discharged from the lower part, and the overflow is discharged from the lower part;

(3) Lateral flow means that tailings slurry is fed in from one side, sediments are discharged from the bottom, and overflow is discharged from the other side.

Since the concentration of iron tailings is generally low, the thickener is equivalent to a clarification device. Its sedimentation area can be calculated based on the rising speed of the clarified water in the thickener and the sedimentation speed of the finest particles in the material to be recovered. 

The inclination angle of the inclined plate is also an important concentration parameter. The sum of the area of ​​the thickener is the sum of the horizontal projection area of ​​each layer of the inclined plate. In a certain range, when the inclination angle is less than a range, the relative sedimentation velocity of solid particles will be reduced, and the liquid flow between the inclined plates will be affected. In order to work normally, the solid particles falling on the inclined plates can flow by themselves. The discharge angle cannot be too small. So choose 45 degrees-60 degrees.

The spacing between the plates has a great influence on the concentration effect. When the distance between the plates is small but the production capacity is the same, the size of the thickener will be too small. The distance between the plates is small, and a large number of inclined plates can be accommodated on the same level, which can help increase the sedimentation area of ​​the thickener. However, if the board spacing is too small, the surface of the inclined board will rub against the fixed particles that have fallen on the board from sliding down, and bring certain difficulties to the use and maintenance of the equipment.

The core key to the promotion and application of inclined plate concentration equipment lies in the material selection and production of the inclined plate. The range of material selection is relatively wide, and the best can be selected according to the conditions of use. Board materials with the characteristics of chemical stability, sufficient strength, light weight and cheapness, non-toxicity, smooth surface, good hydrophobicity, antistatic, and aging resistance can all be used.

If the conditions of use allow, the length of the inclined plate is longer to increase the unit footprint of the thickener.

At the same time, in order to ensure that the material can be evenly covered in the width direction and to avoid the deflection and deformation of the board surface in normal work, the width of the board should not be too large, usually no more than 0.8 meters.

Do you know the vibration device of the thickener?

 The thickener is a solid-liquid treatment equipment used in the concentrator. In order to improve the treatment effect of the thickener per unit area and improve the efficiency of the thickener, the high-efficiency thickener or the inclined plate thickener will be selected. High-efficiency thickeners will increase the height of the straight wall section of the thickening tank, and use appropriate fabrics to add flocculants to improve concentration efficiency. In some concentrators, the materials are small and viscous, the sedimentation speed is slow, and the flocculant cannot be used due to the nature of the material. At this time, the inclined plate thickener is used. The thickening pool of the inclined plate thickener will be divided into a number of equally divided sectors, and each sector will be arranged at a certain interval into a certain angle of inclined plate or inclined tube. The fine particles of the material in the lower part of the thickening tank will naturally settle on the inclined plate and the inclined tube. In this way, the settling distance of the material particles can be shortened by the inclined plate or the inclined tube, and the settling time can be reduced to increase the thickener. The precipitation area to improve concentration efficiency.

The inclined plate thickener will be affected by the nature of the material and the material of the inclined plate during use, and the phenomenon of adhesion between the inclined plates will often occur, which is what we often say that the material that settles on the inclined plate or the inclined tube is not Continuous sliding, on the contrary, the material will settle to a certain thickness before the whole fall. This phenomenon is commonly called hanging material. The whole falling material will be filled with the cone pit of the thickening tank, but because the thick material is too thick, it will cause the harrowing phenomenon after the lifting device fails. There may even be a phenomenon that the inclined board or the inclined board collapses. When the inclined plate thickener has material hanging, the user will use high-pressure water flushing to solve the problem. During the reprocessing process, the overflow water of the thickener will run off and the thickener will stop to clear the pool, which will affect the thickener. Normal use.

In response to this situation, a vibration device for the inclined plate thickener was designed. This vibration device is not only suitable for ordinary central drive thickeners, but also for high-efficiency deep cone thickeners and other types of inclined plates or inclined tubes. Thickener.

The vibration device is generally composed of a vibration rod, a connecting rod, a vibration ring and an electric control box. The vibrator consists of a vibration motor and a motor frame. Composed of shock-absorbing spring and support frame. When installing the vibrator, the support in the vibrator is placed on the bridge of the thickener on site and adjusted to a suitable place for fixing. The lower part of the connecting rod and the vibrating ring can be fixed with bolts. The connecting rod, the motor frame and the vibration ring will be rigidly connected. In order to reduce the impact of the vibrator on the bridge frame of the thickener during the working process, a shock-absorbing spring can be used between the vibrator and the bridge frame to relieve the high-frequency excitation generated by the vibrator Vibration of the force on the bridge.

When the inclined plate vibration machine is working normally, the thickener enters the lower part of the thickening tank from the feeder. The coarse particles in the incoming slurry naturally sink, and the fine materials in the lower part of the thickening tank will naturally sink into the cavity of the inclined plate, but due to the small distance between the inclined plates, the particles only need to settle a small distance , You can settle on the inclined board.

The installation structure of the vibrator device is very simple, easy to install, and reliable in operation. It is very suitable for the beneficiation method where the material is small and thick, the speed is very slow, and it is not easy to fall off. The vibration device can be used for power-driven thickeners equipped with inclined plates or inclined tubes. This vibrating device has a certain reference effect for the technical reform of the new thickener and the technical improvement of the old inclined plate.