RU2640198C1 - Rotation-percussion evaporator and method of vacuum transfer of complex liquids on its basis - Google Patents

Abstract

FIELD: machine engineering.SUBSTANCE: rotation-percussion evaporator for the evaporation of liquids, such as crude oil and petroleum products, consists of a sealed chamber, an evaporation of the spray dispenser, providing diffusion supplied thereto prepared liquid submitted in the below evaporation chamber with low-flow, steam inlet connected to the device for pumping steam, creating a preset vacuum in the evaporator chamber, and an accumulator of non-evaporated liquid. The evaporator is characterised in that the evaporator chamber has a crown of impact blades on the blade wheel, rotating at high speed on the shaft, introduced into the vaporisation chamber through the seal and driven by the drive, so that the droplet flow of the liquid from the spray dispenser, partially evaporating, moves towards the rotating percussion blades, which cut off small drops of droplets from it and strike powerful blows on them. Percussion blades have a sufficiently large surface area and are tilted to the plane of rotation, so as to maximize the intensity of the applied strokes, resulting in part of the liquid is sprayed and evaporates, while the other spreads on a surface percussion blades as dynamic films which, crushing and evaporating, flow down to the edges of the percussion blades, acquiring the velocity of percussion blades, break off from the edges of the percussion blades, disintegrate and continue to move, spraying and evaporating, towards the walls of the evaporation chamber, experience powerful impacts when they collide with the walls of the evaporation chamber, after which they partially evaporate and spread on the inner surface of the evaporation chamber in the form of a dynamic film that evaporates and flows downwards where the accumulator of unevaporated liquid is located, while the formed vapor is withdrawn through the intake using a steam evacuation device, for example a vacuum pump. A method of vacuum distillation of complex liquids based on a rotary-impact evaporator is also claimed.EFFECT: rotary percussive evaporator can effectively evaporate liquid possessing an unfavourable for traditional evaporation of thermophysical properties, as well as liquids with useful components affected thermochemical reactions and coking, direct heat input during the evaporation in the rotary percussive evaporator is not provided and not needed.4 cl, 3 dwg

Description

FIELD OF THE INVENTION

The claimed invention relates to devices for intensifying the evaporation of liquids by increasing the evaporation surface, including by spraying, as well as to methods for vacuum distillation of complex liquids based on such devices. It can be used in various technological processes involving the evaporation of liquids, which include the following processes:

- distillation of oil and oil products;

- purification and desalination of water;

- obtaining elite essential oils and spirits from liquid semi-finished products of plant origin.

The claimed invention is effective in a fairly wide range of atmospheric pressures in the evaporation chamber, including vacuum. It can be used to evaporate liquids with physical properties that are unfavorable for evaporation by traditional evaporative devices. Such liquids include liquids with a high boiling point or with increased viscosity under specified conditions in the evaporation chamber, as well as liquids with a complex composition, which includes components susceptible to thermal destruction or coking when heated.

State of the art

Analogs are known that provide an increase in the evaporation surface due to liquid spraying using atomizing means of a nozzle type in an evaporation chamber in which a vacuum is maintained (RU 2166528, IPC C10G 7/06, B01D 3/10, 06/29/1999; RU 2513857, IPC C19G 7 / 06, C10G 9/00, B01D 3/10, 10/01/2013). The creation of a vacuum leads to a lowering of the boiling point, which facilitates evaporation, and the spray provides an increase in the evaporation surface. Both of these factors, taken separately, are favorable for evaporation. However, vacuum is an unfavorable condition for spraying. The droplets in the drip streams flowing out of the spray means become too large. This is due to the fact that with a decrease in the density of the medium into which the fluid flows, the intensity of their interaction, which provides a spray, decreases. This phenomenon is well known in the aircraft engine industry as applied to fuel atomization in combustion chambers and is described by many authors, including the book: A. Lefebvre, Processes in GTE combustion chambers, Mir, Moscow, 1986. Faced with the unfavorable effect of vacuum, the authors of analogues are forced to were to resort to supporting measures. Spraying using nozzle-type spraying aids was supplemented by assistive techniques to facilitate grinding. The increase in the evaporation surface was supplemented by the formation of films of non-evaporated liquid on the walls of the evaporation chamber. Auxiliary methods for grinding were either the direction of the droplet jets from the spray means to the obstacle in the form of a fixed wall or the direction of these jets at each other.

In the analogue closest to the claimed invention (RU 2166528, IPC C10G 7/06, B01D 3/10, 06/29/1999), considered as a prototype, an auxiliary method for grinding was the direction of droplet jets from spraying means to an obstacle in the form of a fixed wall. Even taking into account the formation of films of non-evaporating liquid on the walls of the evaporation chamber and the obstacle, this was not enough to provide the necessary evaporation rate, and a heat supply was organized to the fixed wall. The disadvantage of the prototype is the lack of effectiveness of the means used to increase the evaporation surface. In fact, all of them use only the energy that was stored in the liquid before being fed into the evaporation chamber. As a result, in the prototype it is not possible to provide the desired degree of grinding of the liquid, which would allow to abandon the uncontrolled heat supply during the evaporation process. Uncontrolled heat supply leads to the risk of irreversible thermochemical reactions and coking.

Disclosure of invention

The objective of the claimed invention is to increase the efficiency of the means intended to increase the evaporation surface in the evaporation device, in a fairly wide range of pressures in the evaporation chamber, including vacuum. The technical results of solving this problem will be an increase in the evaporation rate of liquids with various physical properties, including unfavorable for evaporation by traditional evaporation devices, as well as a complete rejection of uncontrolled heat supply directly during evaporation.

This is achieved by the fact that, unlike the prototype, the droplet stream from the spraying means of the nozzle type is supplied not to the fixed wall, but towards the rotating shock vanes installed in the evaporation chamber. The spraying means is equipped with a regulating element, which allows metering and supplying liquid to the evaporation chamber with a sufficiently low flow rate. Impact blades have surfaces with a sufficiently large area and are mounted on a blade rim rotating on the shaft at a sufficiently high speed. During rotation, the shock vanes cut off small droplets of liquid from the droplet stream and inflict powerful blows on them. These impacts lead to the dynamic spreading of fluid over the surface of the shock vanes and intense evaporation. Evaluation calculations show that, ceteris paribus, in this case, the resulting power ratio of grinding per unit mass of liquid, even at moderate subsonic speeds of shock blades, will be many orders of magnitude higher than the power ratio of grinding in the prototype. This inevitably leads to more efficient grinding, an increase in the area of evaporation and intensification of evaporation.

It should be noted that this approach allows one to increase the evaporation rate over a rather wide range of pressures in the evaporation chamber, including vacuum. In this case, in vacuum, the resistance of the medium to the movement of the shock vanes is significantly reduced, and the energy consumption for the rotation of the crown of the shock vanes is significantly reduced. The high power-to-weight ratio of grinding makes it possible to efficiently evaporate liquids with various physical properties, including unfavorable for evaporation by traditional evaporation devices. Provided that the initial liquid is preconditioned, the supply of heat directly during the evaporation process can be completely eliminated.

Description of drawings

In FIG. 1 shows a longitudinal section of the basic version of the claimed rotary shock evaporator. In FIG. 2 shows a cross section of the basic design of the claimed rotary shock evaporator. In FIG. 3 is a cross-sectional view of an improved embodiment of the inventive rotary-impact evaporator, which allows it to independently pump the generated vapor and maintain a given vacuum in the evaporation chamber due to the inclination and profiling of the shock vanes.

The implementation of the invention

In the basic version, the rotary shock evaporator contains a sealed evaporation chamber (1), a crown of shock vanes (2), a blade wheel (3), a shaft (4), a seal (5), a drive (6), an inlet fluid line (7), spray dispenser (8), steam intake (10), a device for pumping steam (11), a discharge steam line (12), a storage ring (14), a crane (15), a discharge liquid line (16).

It is important to note that the drive (6) can be an electric motor, the device for pumping steam (11) can be a vacuum pump. Impeller blades (2), the surfaces of which have a sufficiently large area, are inclined to the plane of rotation so that, taking into account the relative position of the impeller (3) and the spray dispenser (8), the maximum intensity of impacts on droplets of liquid from the spray dispenser (8) is ensured.

Rotary-shock evaporator in the basic version operates as follows.

A device for pumping steam (11) provides a predetermined vacuum in the evaporation chamber (1). The impeller (3), on which the crown of the impact vanes (2) is mounted, is driven by the drive (6) through the shaft (4) inserted into the evaporation chamber (1) through the seal (5). The initial fluid enters the spray dispenser (8) through the inlet fluid line (7). From the spray dispenser (8), the liquid in the form of a droplet jet (9) is supplied to the evaporation chamber (1) to meet the shock vanes rotating at a sufficiently high speed (2). During the rotation, the impact vanes (2) cut off small droplet portions from the drip jet (9) and deliver powerful blows to them. As a result, one part of the liquid is sprayed and vaporized, and the other part of the liquid spreads over the surface of the shock vanes (2) in the form of dynamic films. Films, crushed and evaporated, flow to the edges of the impact blades (2). In the process of film draining, the speed of the shock vanes (2) relative to the walls of the evaporation chamber (1) becomes. Tearing off the edges of the shock vanes (2), the films disintegrate and continue to move, evaporating, towards the walls of the evaporation chamber (1). Powerful blows occur again. The liquid is again partially atomized and evaporated, and partially spreads over the inner surface of the evaporation chamber (1) in the form of a film, which, being crushed and evaporated, flows down. The selection of the formed steam is carried out through the intake (10) using a device for pumping steam (11). Next, the steam enters the exhaust steam line (12). Unevaporated liquid (13) is collected in the accumulator (14), from where at a given time it is taken out through the valve (15) and sent further along the discharge liquid line (16).

In a modified version for steam evacuation, the rotary percussion evaporator contains shock vanes (2), which are given a shape similar to the shape of vanes in a vane vacuum pump. Moreover, the angle of inclination of the shock vanes (2) to the plane of rotation is similar to the angle of inclination of the blades to the plane of rotation in a vane vacuum pump. The remaining elements in this version are the same as in the basic version, with the exception of the device for pumping steam (11), which may be absent. The rotary percussion evaporator in this version works like a rotary percussion evaporator in the basic version, except that the rotation of the shock vanes (2) provides not only powerful strikes on small droplets of the initial liquid, but also pumping out the generated vapor, as well as maintaining preset vacuum in the evaporation chamber.

In a modified fluid grinding design, the rotary shock evaporator contains shock blades (2), the surfaces of which are given a ribbed shape. The ribs are directed across the movement of the liquid film spreading after the initial impact. The remaining elements in this version are the same as in the basic version or in the version modified for pumping out steam. A rotary-impact evaporator in a modified refinement of liquid grinding works similarly to a rotary-shock evaporator in one of the two previous versions, except that the film spreading after the initial impact of the liquid experiences numerous impacts of lower intensity when crossing the ribs. These strokes contribute to additional grinding of the liquid and additional intensification of evaporation.

The ability of a rotary shock evaporator in a modified version for steam evacuation to independently maintain a given vacuum level in the evaporation chamber makes it attractive for use in the vacuum distillation of complex liquids. Vacuum distillation methods are based on the fact that components with different physical properties evaporate with different intensities, and after condensation of the vapor in the condenser, a liquid is enriched with a more evaporated component. A feature of the claimed method is the use of a rotary shock evaporator. This affects both the evaporation process itself and the requirements for the preliminary preparation of the liquid. Extraneous inclusions capable of damaging the shock vanes must be removed from the liquid, and the temperature of the liquid must be brought to a level optimal for the operation of the rotary-impact evaporator.

The method of vacuum distillation of complex liquids using a rotary shock evaporator is as follows.

The initial complex liquid is preliminarily prepared by filtration and a controlled adjustment of its temperature to a level optimal for the operation of a rotary shock evaporator. At the same time, a rotary shock evaporator is driven, a blade wheel is untwisted and a vacuum is created in the evaporation chamber. Vacuum can be created both due to the rotation of the shock vanes, and due to a separate vacuum pump. Then, the prepared liquid is fed through the spray batcher into the evaporation chamber, where during the sequence of powerful shocks and the formation of dynamic films, steam is formed enriched in the easily evaporated component of the initial liquid. The resulting vapor is taken from the evaporation chamber either due to the pressure created by the rotation of the shock vanes, or due to a separate vacuum pump, and fed to the condenser. The liquid formed in the condenser is enriched with a volatile component. The liquid that has not evaporated in the evaporation chamber is enriched with the remaining components.

Claims (4)

1. Rotary shock evaporator for the evaporation of liquids, such as oil and petroleum products, consisting of a sealed evaporation chamber, a spray dispenser, which provides a spray of prepared liquid supplied to it, supplied to the evaporation chamber with a low flow rate, a steam intake connected to a device for pumping steam, for example, a vacuum pump that creates a predetermined vacuum in the evaporation chamber, and an accumulator of non-vaporized liquid, characterized in that a crown of shock vanes is installed in the evaporation chamber and a blade wheel rotating at high speed on a shaft inserted into the evaporation chamber through a seal and driven by a drive, which can be an electric motor, so that the droplet fluid flow from the spray dispenser, partially evaporating, moves towards the rotating shock vanes, which are cut off from small dropping portions and inflicting powerful blows on them, and the shock vanes have a sufficiently large surface area and are inclined to the plane of rotation so as to ensure maximum intensity the impact of strikes, as a result of which part of the liquid is sprayed and vaporized, and the other spreads over the surface of the shock vanes in the form of dynamic films, which, crushing and evaporating, flow to the edges of the shock vanes, acquiring the speed of the shock vanes, break from the edges of the shock vanes, disintegrate and continue to move, spraying and evaporating, towards the walls of the evaporation chamber, experience powerful shocks when they collide with the walls of the evaporation chamber, after which, partially evaporating, spread over the inner the surface of the evaporation chamber in the form of a dynamic film, which, evaporating, flows down to where the accumulator of non-vaporized liquid is located, while the generated vapor is discharged through the intake using a device for pumping steam, such as a vacuum pump. 2. The rotary-impact evaporator according to claim 1, modified by pumping out steam, in which the shock vanes are given a shape similar to the shape of vanes in a vane vacuum pump, and the angle of inclination of the shock vanes to the plane of rotation is set close to the angle of inclination of the vanes to the plane of rotation of the vanes a vacuum pump, which, along with grinding the liquid, allows for pumping out the steam and maintaining the necessary vacuum in the evaporation chamber due to the rotation of the shock vanes, and also allows you to abandon a separate device for pumping pa. 3. The rotary-impact evaporator according to claim 1 or 2, modified by grinding the liquid, in which the surface of the shock vanes is given a ribbed shape, the ribs being directed across the movement of the dynamic fluid film spreading after the initial impact and inflicting numerous hits of lower intensity on it, which contributes to additional grinding fluid and additional intensification of evaporation. 4. The method of vacuum distillation of complex liquids based on a rotary shock evaporator according to paragraphs. 1, 2 or 3, according to which vacuum distillation is ensured as a result of creating a vacuum in the evaporation chamber, supplying liquid to the evaporation chamber in the form of a droplet jet, evaporation of the easily evaporated liquid component, selection of steam from the evaporation chamber and its condensation in the condenser, as a result of which in the condenser, liquid enriched in the volatile component accumulates, and in the evaporation chamber, non-vaporized liquid enriched in the volatile component accumulates, characterized in that This is ensured by a rotary-shock evaporator, into which the prepared liquid is supplied without foreign inclusions with a temperature brought to a level optimal for the operation of the rotary-shock evaporator, in which the vacuum is created by the vacuum pump, and the increase in the evaporation surface is ensured by powerful shocks applied in portions of liquid by shock blades.

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