Effect of filter media on centrifuge vibration
Effect of filter media on centrifuge vibration
Abstract This paper analyzes the vibration of the fully automatic centrifuge, and proposes the effect of the filter media on the vibration and the solution to the problem.
Keywords Centrifuge, filter media, vibration Our company has installed a SGZ1000 three-foot full-discharge automatic centrifuge in recent years. In the trial production process, it was found that the centrifuge operated smoothly under no load, but it produced strong vibration after feeding. Repeated trials have shown this phenomenon. Therefore, a comprehensive inspection of the centrifuge eliminated the mechanical causes of the centrifuge itself. Then, the process ratio was adjusted to reduce the slurry concentration to reduce clogging, and the feed pipe and slurry distributor were rectified. After these measures were taken, the centrifuge feed was basically continuous and uniform, but the vibration was eliminated. No obvious results have been seen. Finally, we superimposed a layer of polyester 747 filter cloth on the polypropylene monofilament filter cloth provided by the centrifuge factory, which basically eliminated the vibration. After nearly a year of practice, the effect was good. , Reason analysis 1.1 Slurry characteristics The density of materials processed by our company is 1731kg / m3, and the particle size is relatively large (30 ~ 40ptm), so the macroscopic flow characteristics dominate. The main component of the liquid phase is petroleum ether, with low viscosity and easy volatility. The temperature of the slurry is a 10-10 C, and its viscosity decreases as the temperature decreases. Therefore, the slurry is very easy to solid-liquid separation and has a strong settling property.
1. 2. Filter media The filter media uses polypropylene monofilament filter cloth with high porosity and low specific resistance. When filtering, it has the advantages of fast separation speed, not easy to block, and good interception effect.
l. 3. The distribution of the material in the centrifuge The slurry obtains a certain speed through the distributor, and the speed of reaching the surface of the filter screen is accelerated again. Because the specific resistance of the polypropylene filter cloth is very small, the liquid phase quickly passes through the filter screen to be discharged as filtrate, while the solid phase After the phase separation, the fluidity decreases, and it quickly accumulates on the surface of the filter medium and rarely flows. Due to the large settling properties of the slurry, the slurry concentrations are not uniform and vary widely. In fact, this kind of situation is equivalent to the sudden change of the feed, which leads to an uneven material distribution (thickness), that is, a serious bias. The maximum value of the bias is m: AX can reach 1: 1. (As shown in Figure 1). When the centrifuge rotates, it generates a considerable radial unbalanced centrifugal force. It is generally believed that this situation can only cause severe horizontal vibration. However, in fact, vertical vibration always occurs at the same time with horizontal vibration. Under the action of radial unbalanced centrifugal force, the chassis hanging on the boom will swing like a pendulum, creating a vertical position difference. Repeating this movement will cause vertical vibration. The greater the radial imbalance force, the greater the horizontal vibration and vertical vibration. The vibration is thus generated.
2 Solutions How to eliminate or reduce this vibration? The fundamental method is to reduce the radial unbalanced centrifugal force. The centrifugal force is proportional to the mass and speed. Although the speed of the centrifuge can be reduced by feeding, this can achieve this purpose, but it also reduces the separation efficiency. In actual production, due to the reduction of centrifugal force, the slurry will fall from the lower discharge port without separation under the action of gravity, which seriously affects daily production.
Obviously, only by distributing the materials uniformly to reduce the unbalanced centrifugal force can the vibration be completely resolved. In ordinary three-legged centrifuges, we can use feed at rest to solve this problem. In fully automatic unloading centrifuges, this obviously does not work. According to the above analysis, the reason for the uneven distribution of materials is that the separation speed of the slurry on the surface of the filter screen is too fast and lacks a certain fluidity. After adding a layer of polyester 747 filter cloth, the specific resistance of the polyester filter cloth is larger than that of the polypropylene monofilament filter cloth, so the residence time of the liquid phase on the surface of the filter medium can be extended, so that the slurry has a certain degree of flow Sex. Under the action of centrifugal force and gravity, it flows to the thin layer of the material layer to compensate for the uneven distribution of the material caused by the different slurry concentrations. The purpose of reducing radial unbalanced centrifugal force and eliminating vibration is achieved. Practice has proved that the increase in separation difficulty caused by this method has little effect on production, and avoids the problem of leakage caused by the reduction of the centrifuge speed.
3 Conclusion In separation theory. The lower the specific resistance of the filter media, the better the separation effect. However, in actual operation, no specific analysis is performed on specific materials, and a filter medium with a low specific resistance is blindly selected to pursue the separation speed, but it will adversely affect the separation machinery and its actual use. Therefore, a reasonable comprehensive effect should be pursued in practice, which is the best way.
Dining Chair,Dining Room Chairs,Dining Room Table Sets,Leather Dining Chairs
Foshan Poesy Furniture Co., LTD. , https://www.poesy-furniture.com