SU753475A1 - Apparatus for regeneration of filtering sieve for rotor of centrifugal unit with blade-type discharging of sediments - Google Patents

Description

(54) DEVICE FOR REGENERATING FILTER Sieve ROTOR CENTRIFUGES WITH KEYBOARD SUCTION DOWNLOAD

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The invention relates to chemical engineering, in particular, to devices for regenerating filtering screens of rotors of centrifuges with knife discharge of sediment, which are used in the chemical, petrochemical, pharmaceutical and other industries.

The high productivity of these centrifuges, the unloading of sediment on the move, without stopping the rotor, and a number of other design advantages, make wide use of knife centrifuges. However, a layer of sediment (sublayer) remains on the filtering surface of the rotor after the operation of cutting the sediment, which can no longer be removed with a knife. When processing compacted sediments, the resistance of the sub-layer increases to such an extent that filtration through it practically ceases. In this case, to regenerate the filter base, it is necessary to dissolve the residual layer of sediment or, if it is insoluble, remove it mechanically.

A device for removing a sediment sublayer from a rotor filter sieve is known, which is a brush mounted on the blade body 1. In the usual mode

the brush is retracted to the lower extreme position and does not move the operation of cutting the sediment with a knife. When performing a sieve cleaning operation, the brush presses close to the screen using a hydraulic cylinder and cleans the sediment. This design was also carried out in domestic centrifuges. On the basis of their experience of operation, the following remark can be made about the operation of this mechanism: with an elastic brush, complete cleaning of the sieve is not achieved;

(An increase in the stiffness of the bristles improves the cleaning of the sieve, but leads to the netting of the mesh itself. The use of such a cleaning mechanism is completely impossible if different fabrics are used as the filtering base.

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It is also known a device for removing the sediment sublayer, made in the form of a special knife with a ridge of rippers 2. The ripper ridges are made on the back side of the knife and look like a tre20 of coal pyramids, the tops of which are located higher than the plane of the cutting edge. A knife of this design cuts the sediment with a cutting edge, and the residual layer is loosened by ridges. This increases the porosity of the sediment, decreases its moisture and improves its filtration capacity.

The use of a knife with a comb and rippers approximately halves the frequency of tissue regeneration, and increases the productivity of centrifuges. All this, however, does not exclude the operation of periodically removing the sublayer by mechanical means. Performing such an operation manually when handling toxic or flammable products is generally impossible.

The closest to the invention to the technical essence of the achieved result is a device including a nozzle for supplying a wash liquid and a nozzle of a pneumatic suction device 3.

The destruction of the sub-layer is produced by a jet of fluid supplied under high pressure through nozzles located across the entire width of the rotor. This device is a mounted rotor, part of the rotor, next to the bunker, the discharge of dry sediment. In order to avoid boiling water and various sediments in the dry product, the erosion zone is enclosed by a chamber pressed with the help of an hydraulic cylinder to the surface of the sediment and ro | 0) a. The elimination of the edges of the chamber of elastic material increases its tightness. The stress of the smeared sediment from the chamber is produced by liquid. To improve the process of unloading, the chamber can be connected to a suction device. M, on nHFviep with a vacuum pump.

However, this device has two very significant drawbacks. Firstly, the scouring device is located in the part of the rotor that is occupied by other working bodies in centrifuges — a rotary knife is usually placed here to cut the sludge, a sludge discharge hopper, a slurry feed pipe to the rotor, a flush liquid supply pipe, a device (a flag) D. to determine the level of loading of the rotor.

) - The need for a germetnization of the camera of a dilated device, a tight pressing of the chamber to the sieve (A second drawback was identified - the lack of reliable removal of the smeared sediment from the chamber. Using a vacuum pump that should work on the mixture (with liquid and sediment) In addition, sealing the chamber in which the eroded sediment accumulates precludes obtaining a gas velocity sufficient to transport and reliably remove solid sediment particles.

In addition, there is no device for separating the pumped gas from the liquid and sediment.

The aim of the invention is more complete screen cleaning.

The goal is achieved by the fact that the nozzle for supplying the washing liquid and the nozzle of the pneumatic suction device are located in the lower part of the rotor so that their axes intersect

At a point located on the surface of the sieve. As a result, the erosion zone is combined with the suction zone, which ensures effective removal of the diffuse sediment and high quality of screen cleaning. The location of the washout nozzle at the bottom of the rotor prevents the washout liquid and wet sediment from entering the dry sludge discharge bin.

FIG. 1 schematically shows a centrifuge with the described device; in fig. 2 is a longitudinal section of a centrifuge with parts of the device; in fig. 3 - cross section; in fig. 4 - the working position of the nozzles during the regeneration operation.

A centrifuge 1 with a device for regeneration includes a high pressure pump 2, for example, a plunger supplying liquid, to the nozzle 3 to open a wash sublayer.

The pulverized sediment discharge system contains a swiveling nozzle. 4 suction, cyclop 5 for separating sediment and liquid from gas, bunker 6 for collecting sediment and washing liquid and high pressure fan 7. A tube 9 is used to supply the cleaned gas to the cavity of the rotor 8 of the centrifuge.

A tap 10 is used to release sediment and liquid from the hopper 6.

The rotation of the pneumatic suction nozzle into the working position is carried out by the hydraulic cylinder 11.

Slow rotation of the rotor with a peripheral speed of 0.1-0.5 m / s during the regeneration operation is carried out by an additional drive 12.

The operation of the regeneration device is as follows. 5 After carrying out several technological cycles of loading, filtering and cutting the sediment when the sediment is compacted and filtration through the underlayer is stopped, the rotor 8 of the centrifuge is stopped and the auxiliary drive 12 is turned on. The nozzle 4 of the pneumatic suction rotates before contact with the sediment, as shown in FIG. 4. The fan 7 and the high pressure pump 2 are turned on. After rotation of the sonl 4, the axes of the sonl 3 and 4 are directed so that 5 they intersect at a point lying on the surface of the sieve. Such an orientation of the nozzles ensures the combination of the erosion zone and the suction zone, and this, in turn, allows for the effective removal of the diffuse sludge and high quality screen cleaning.

During the regeneration operation, the rotor must make at least two full revolutions: at the first revolution, the underlayer is destroyed and sediment is removed; at the second and subsequent revolutions 55, a thorough cleaning and washing of the sieve is achieved.

The sucked sediment and washout liquid are separated from the gas in the cyclone 5 and collected in a hermetically sealed bunker 6. The gas returns through pipe 9 to the rotor 8 of the centrifuge.

After completion of the regeneration operation, the working bodies return to their original position, all units of the device are stopped, the hopper 6 is unloaded, the main drive of the centrifuge is turned on, and the centrifuge begins again in the process.

The proposed device for regenerating filtering screens of the rotor of the centrifuge with the unloading of sediment especially effectively in chemical plants processing toxic suspensions with insoluble solid phase, in which the contact of the operating personnel with the product is excluded.

Claims (3)

1. US patent number 3034654, class, 210-372, published. 1962. 2. USSR author's certificate number 338266, cl. B 04 B 7/00, 1972. 3. The patent of Germany No. 919879, cl. 82 8 6/01, publ. 1954 (prototype). Sediment under s / 10 FIG. eight Area blurred under / 1ol