RU2566137C2 - Centrifugal extractor - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: centrifugal extractor contains the drive, the bearing support, the housing with the mixing chamber and chambers for removal of light and heavy phases of the processed liquid medium, the rotor with the separation chamber, the transporting device, tubes for light phase removal, the hydraulic lock with channels for heavy phase removal. All details contacting with the processed medium are made of chemical and resistant polymeric materials, while there the rigid link between the drive shaft and the rotor is provided. The torque from the engine shaft is transferred to the loaded and strength polymeric details of the product, at least, through one the metal stress-relief element distributing the load in the volume of the polymeric detail. The housing cover which is the base for the engine fastening also has the strength and stress-relief element in the form of the metal flange joined with the cover by the screw connection through screw threaded bushings and intended to provide constant mutual position of extractor details and assemblies. All metal details of the extractor and trans-extractor space are isolated from aggressive components of the processed liquid medium by a complex of labyrinth seals.

EFFECT: improvement of tightness of the device with simultaneous improvement of corrosion resistance of its details to the processed liquid medium.

1 dwg

Description

The invention relates to designs of centrifugal extractors for a liquid-liquid system, for use mainly in the chemical, radiochemical, petrochemical, hydrometallurgical, pharmaceutical industries for the cleaning and separation of difficult to separate, aggressive, radioactive, toxic, explosive, fire hazardous and other harmful to human health and environmental fluids.

It is known that it is most advantageous and advisable to use centrifugal extractors where they have decisive advantages over other extraction devices, namely:

- for processes in which it is necessary to realize the difference in the speed of extraction of elements to increase their separation coefficients;

- for processes in which viscous and slightly different in density liquids are used, prone to the formation of stable emulsions;

- for processes requiring a short phase contact time due to the destructive effect of radioactivity on the extractant or changes in the properties of solutions over time;

- for processes requiring limitation of the volume of liquids, for example, due to the nuclear and toxic hazards of liquid media, explosion and fire hazard of the extractant.

However, when using centrifugal extractors under various extractants and working solutions, the problem arises of ensuring the corrosion resistance of the extractor, namely all parts of the extractor in contact with the processed liquids. The manufactured extractors from stainless or titanium alloys are limitedly corrosion resistant in acidic working solutions at temperatures of + 5-100 ° C. In the indicated temperature range, the most resistant to acid solutions, which are a component of acidic working solutions, are polymeric materials, for example polyethylene, polypropylene, fluoroplastic and some others, and composite materials with a binder based on the above polymers. However, if they are used in the design and construction of extractors, it is required to take into account their comparatively low structural rigidity and strength compared to metal alloys, and the presence of cold flow phenomena for some polymers. These factors impede the introduction of polymers in the production of industrial series centrifugal extractors (with rotor diameters greater than 125 mm), where it is especially required to ensure good balancing of the rotors and the tightness of the apparatus in the zone of energy supply from the drive.

Currently, this problem has not been solved for industrial series extractors. When conducting patent research, the applicant did not find technical solutions known from the prior art that would ensure the use of polymers and polymer composites for the manufacture of centrifugal extractors with a large rotor diameter (more than 125 mm).

From the above it follows that the solution of this problem is of great importance. The need to solve the problem is important because large-scale research work is underway to separate rare-earth metals concentrate into individual elements for their further use in various high-tech industries. A complete separation cycle involves working with a liquid-liquid system of various chemical composition. The use of polymers and composites based on them will create industrial dynamic extractors with greater versatility in use. Modern methods of processing polymer materials and composites with a polymer binder can significantly reduce the cost of the product compared to its metal counterparts, which will make the use of extraction technology more affordable in various industries.

More specifically, the device relates to the technology of separation and purification of substances, including rare earth metals, purification and separation of radioactive, aggressive, toxic, explosive and other liquids harmful to human health and the environment and can be used in chemical, hydrometallurgical, pharmaceutical and other industries industry.

A centrifugal extractor is known (RU 1546096, class B01D 11/04, published July 10, 2010), which differs from the proposed construction in that, although the extractor motor is also isolated from the processed fluid, the power element, which is combined with the driven clutch, transmits a torque moment on the rotor of the extractor, but unlike the proposed model is subject to the vapor-droplet component of the processed medium. Sealing the engine is achieved by eliminating the tight connection with it, which complicates and dramatically increases the cost of the design and under certain conditions worsens the control of the executive body.

A centrifugal extractor is known (RU 2060778, class B01D 11/04, published May 27, 1996), which differs from the proposed construction in that the metal power elements through which torque is transmitted to the rotor are not protected from the influence of the processed medium.

Known centrifugal extractor (RU 96498, class B01D 11/04, publ. 10.08.2010), in which, as in the proposed model provides for the protection of the engine from exposure to the processed environment. Sealing the engine is achieved by eliminating the tight connection with it, which complicates and dramatically increases the cost of the design and under certain conditions worsens the control of the executive body.

These disadvantages of the known centrifugal extractors are absent in the inventive centrifugal extractor, the design of which provides a high level of balance and tightness in the polymer design. Extractors are more versatile in corrosion resistance and can work with all organic and inorganic acids in the temperature range 0-100 ° C.

The technical result is an increase in the tightness of the apparatus, while increasing the corrosion resistance of its parts to the processed liquid medium.

The technical result is achieved by a centrifugal extractor containing a drive, a bearing support, a housing with a mixing chamber and output chambers of light and heavy phases of the processed liquid medium, a rotor with a separation chamber, a conveying device, tubes for outputting a light phase, a water seal with channels for draining the heavy phase. All parts in contact with the processed medium are made of chemically resistant polymer materials, while there is a rigid connection between the drive shaft and the rotor, the torque from the motor shaft is transmitted to the loaded and power polymer parts of the product through at least one metal unloading element, distributing the load over the volume of the polymer part. The housing cover is the base for mounting the engine, it also has a power and unloading element in the form of a metal flange connected to the said cover with a screw connection through screw threaded sleeves and designed to ensure a constant relative position of parts and components of the extractor. All metal parts of the extractor and the extra-extractor space are isolated from the aggressive components of the processed liquid medium by a complex of labyrinth seals.

The possibility of manufacturing all parts of the extractor in contact with the processed liquid from polymer materials makes it possible to increase the corrosion resistance of its parts to the processed liquid medium.

The installation between the drive shaft and the rotor of at least one metal unloading element through which torque is transmitted from the engine shaft to the loaded polymer and power units allows evenly distributing the load across the volume of the polymer part of the parts.

The implementation of the housing cover with a power and unloading element, made in the form of a metal flange connected to the housing cover by screw connection through screw threaded sleeves, allows to ensure the constant relative position of parts and components of the extractor.

Performing a labyrinth seal complex in the fixed cover of the extractor and in the rotating hydraulic lock allows isolating all metal parts of the extractor and the extra-extractor space from aggressive components of the processed medium, thereby increasing the durability of the metal parts of the extractor.

The polymer parts of the design of the extractor can be made of polyethylene, polypropylene or fluoroplastic.

In the presented drawing is an illustration of a specific design of the extractor and the method of its operation.

Centrifugal extractor contains: drive - 1; extractor cover with a fixed part of the labyrinth seal of the mechanical type - 2 complete with a metal flange of the engine - 2.1; case - 15 with a mixing chamber - 18, divided into four compartments by ribs - 19 and chambers - 17 and 16 of the output of light and heavy phases, respectively, pipes - 22 and 23 of the output of light and heavy phases, respectively, samplers - 24 with shutoff valves - 25 , pipes - 20 and 21 for supplying the emulsion components to the mixing chamber with an emergency overflow chamber with a breather for venting excess air and with an emergency overflow branch pipe - 26; rotor - 5, consisting of a rotor housing - 6, divided into four chambers by ribs - 9, integrated into a whole with a reflective disk - 11 and a passage ring - 10, tubes - 7 and adjusting nozzles screwed into them - 8 for outputting the light phase, hydraulic lock - 3 with the moving part of the labyrinth seal of the front and radial type assembled with a metal coupling - 3.1, a separation membrane - 4, a transport device - 13, a mixing device - 14, a shaft of a mixing device - 12. An engine flange with an extractor cover, as well as FTA with a water lock are connected by screws through screw threaded sleeves - 30, having threads of different steps - a large step on the outer cylinder, for screwing into polymer and a small step on the inner cylinder, for screwing in the connecting screws. A complex of labyrinth seals, structurally made in the fixed cover of the extractor and in the rotating hydraulic lock, ensures the tightness of the extractor and prevents the ingress of aggressive solutions and their vapors into the extra-extractor space and onto the metal parts of the product. The membrane and the water seal have an additional element in the form of a fixed end key, which serves both to transmit torque from the water seal to the membrane, and to block their mutual circumferential displacement.

The operation of the inventive centrifugal extractor is as follows.

A motor is connected to the mains supply, the shaft of which starts to rotate, causing the hydraulic lock to rotate through a power element, a metal coupling, which functions to distribute the load across the hydraulic lock volume and reduce stresses in the body of the polymer part. From the massive polymer hydraulic lock, the torque is transmitted to the thin-walled rotor housing together with the separation membrane and to the rotor as a whole.

After the rotor has set a predetermined number of revolutions, the initial processed solution through the nozzle - 20, and the extractant through the nozzle - 21 is fed into the mixing chamber - 18, where they are mixed with a stirrer - 14 connected to the rotor shaft - 12.

The ribs 19 located in the chamber 18 prevent the twisting of the liquids during the mixing process. The resulting emulsion is transported by the blade conveyor 13 to the rotor 5. Under the action of centrifugal force in the rotor housing 6, the emulsion is stratified into light and heavy phases, while the ribs 9 assembled with a reflective disk prevent the emulsion from twisting inside the rotor. The light phase moves upward in the central part of the rotor while the heavy phase discarded by centrifugal force moves upward along the inner wall of the rotor. The light phase reaches the level of the nozzles 8, adjusted along the boundary of the separation of phases, and since the inlet openings of the nozzles are in the zone of movement of the light phase in the central zone of the rotor, the latter, overflowing into the nozzles, is removed from the rotor into the chamber 17, from where it is removed from the centrifugal extractor. At the same time, the heavy phase, moving along the inner wall of the rotor, reaches the membrane 4 and through the holes in it enters the cavity of the hydraulic lock. The heavy phase moves to the hydraulic lock overflow and then, passing through the radial holes of the hydraulic lock, enters the chamber for the heavy phase 16 from where it is removed from the extractor through the pipe 23. Samplers 24 with shutoff valves 25, structurally combined to increase the rigidity of the assembly with nozzles 22 and 23, serve to control the quality of the extractor without stopping the separation process. A labyrinth seal formed by a water trap and an extractor cap prevents liquid, droplet-like and vaporous media from entering the extra-extractor space.

From the above description of the invention in statics (see drawing) and in the work it follows that in the inventive centrifugal extractor all loads in polymeric materials are distributed throughout the part. The labyrinth seal prevents the penetration of aggressive working components from the working chambers to metal parts, threaded bushings and into the extra-space.

Thus, the design of the claimed apparatus provides everything in order to achieve the desired result when used in industrial production - to provide the possibility of using polymer materials, as well as composite materials based on polymers, as a material for the manufacture of both the rotor and the extractor body as a whole, and individual product nodes, subject to the introduction of structural elements that unload polymer parts, which makes it possible to make extractors more universal in terms of corrosion resistance spine, as well as reduce the cost of their production.

The invention can be used in industry, as it is characterized by specific design features, each of which is reproducible and does not contradict the use of a centrifugal extractor in an industrial environment. The entire set of essential features of the invention and each feature individually is aimed at achieving the expected technical result - ensuring the applicability of polymer and composite polymer materials in the manufacture of industrial series extractors due to technical solutions that reduce the voltage in the polymer material and increase its structural rigidity.

Claims (1)

A centrifugal extractor comprising a drive, a bearing support, a housing with a mixing chamber and output chambers for light and heavy phases of the processed liquid medium, a rotor with a separation chamber, a conveying device, tubes for outputting a light phase, a water seal with channels for draining the heavy phase, characterized in that all parts in contact with the processed medium are made of chemically resistant polymer materials, while there is a rigid connection between the drive shaft and the rotor, the torque from the motor shaft before is applied to loaded and power polymer parts of the product through at least one metal unloading element that distributes the load along the volume of the polymer part, the housing cover, which is the base for mounting the engine, also has a power and unloading element in the form of a metal flange connected to the said cover screw connection through screw threaded bushings and designed to ensure the constant relative position of parts and components of the extractor, while all metal parts of the extractor and the extractor space is isolated from the aggressive components of the processed liquid medium by a complex of labyrinth seals.