RU2722191C1 - Device (embodiments) for separation of liquid from gas flow, separation element (embodiments) for separation of liquid from gas flow and method of liquid separation from gas flow - Google Patents

Abstract

FIELD: oil, gas and coke-chemical industries.SUBSTANCE: invention relates to oil and gas industry, in particular to the field of gas cleaning from impurities, namely to gas cleaning from suspended drops and vaporous liquid. Proposed device comprises case with uncleaned gas inlet branch pipe, purified gas outlet and separated fluid outlet. Inside the housing between the raw gas inlet branch pipe and the cleaned gas outlet branch pipe there is at least one separation element. Separation element includes at least one grid layer made from wire with non-wettable surface, and at least one grid layer made of wire with wetted surface. In another embodiment, the separation element may include a mesh made of at least one wire with non-wettable surface and at least one wire with a wetted surface. In the third embodiment, the separation element includes a frame with strained in it strings made from wires with non-wettable surface and wires with a wetted surface. At the same time near the string made of wire with wetted surface there is at least one adjacent string made of wire with non-wettable surface.EFFECT: technical result is higher efficiency of separation of vapour and drop liquid from gas flow and reduced gas-dynamic resistance of separation elements.34 cl, 7 dwg, 3 ex

Description

The invention relates to the oil and gas industry, in particular to the field of gas purification from impurities, and in particular to gas purification from suspended droplets and vaporous liquid.

In the oil and gas industry, methods are used to separate the liquid from the gas stream, which consist in the direction of the gas stream with suspended droplets of liquid into special devices that ensure separation (separation) of the liquid from the gas stream - gas separators, consisting of a housing inside which there are separation elements of various types selected depending on the requirements for gas treatment and the performance of the gas separator. Technological systems are used to separate the vaporous liquid before the separation stage, including equipment for cooling the gas flow: 1) gas expansion (throttle, turboexpander, etc.); 2) mechanical gas cooling (chiller with a refrigerant circuit).

The main problem of devices used in industry for separating liquid from a gas stream is the inability to extract vaporous liquid at the gas separation stage, as well as the lack of control over the wettability of the material of the separation elements used in gas separators.

In addition, the formation of a film of the separated liquid on the surface of the separation elements leads to a decrease in the useful area of the separation elements and a decrease in the cross-sectional area available for gas flow, which, in turn, increases the gas-dynamic resistance of the separation element, in particular with an increase in the gas flow rate, and can also lead to the dropping of droplets in the stream of the gas to be cleaned and to the formation of a secondary aerosol when dispersing trapped liquid droplets at high linear velocities of the gas being purified.

A technical solution is known (patent application DE No. 10323155, published December 9, 2004, IPC: B01D 45/08), according to which a device (gas separator) with separation elements is used to separate liquid from a gas stream, of which at least one of them includes a fabric or fibrous material with hydrophobic properties and a nanostructured surface. Due to hydrophobicity and structuring, the surface has low wettability, as a result of which water droplets falling on the surface with a gas stream have a weak interaction with the surface, take an almost spherical shape, roll, merge - coalescence of liquid droplets occurs. As a result of the enlargement of liquid droplets, they flow off the filter due to gravitational forces. A common feature with the claimed technical solution is that the device for separating liquid from a gas stream contains a separation element with a hydrophobic (non-wettable water) surface. However, the use of materials with a hydrophobic surface only in the separation elements is ineffective for ensuring the stable collection and removal of droplet moisture, due to the random movement of water droplets on super-hydrophobic surfaces, especially at high gas flow rates, and the use of fabric or fibrous filter elements leads to high separation resistance elements to the gas flow. In addition, the known method provides for the separation of only droplet liquid from the gas stream, but does not provide for the separation of liquid vapor.

It is known to use a combination of a hydrophobic and hydrophilic surface to separate immiscible liquids, in particular, according to the invention (US patent No. 8409448, published 04/02/2013, IPC: B01D 37/00, B01D 17/022, B01D 17/04), according to which separation lipophilic liquid from the hydrophilic liquid phase, or the separation of the hydrophilic liquid from the lipophilic liquid phase is carried out using a filter made of hydrophilic and hydrophobic fibers. As a result of the interaction of a hydrophilic liquid with hydrophilic fibers, and a lipophilic liquid, respectively, with hydrophobic fibers, the accumulation, coalescence of liquid droplets on the corresponding fibers and their removal from the filter due to gravitational forces occurs. Common features with the claimed invention is the use of a material with a hydrophobic surface and a material with a hydrophilic surface to separate drops of an immiscible lipophilic (oleophilic) or hydrophilic liquid. However, the use of a filter made of fibers does not provide an effective separation of the liquid from the gas stream due to the high gas-dynamic resistance of such materials.

The closest analogue (prototype) is a device for drying steam (CN patent No. 102350182, published 02.26.2014, IPC: B01D 53/26), in which a corrugated plate with a hydrophobic coating containing uniformly distributed inclusions is used to separate droplet moisture from the steam stream. from hydrophilic material. Drops of water from a steam stream interact with hydrophilic inclusions, accumulate, reach a certain size and flow down from the surface. However, due to the hydrophobic surface around the hydrophilic inclusions on the surface of the plate does not form a water film. Common features of the known device with the claimed technical solution is the use of a material whose surface contains areas with a non-wettable (hydrophobic) and a wettable (hydrophilic) coating to separate droplet moisture from the gas stream. However, the design of this device does not allow for the effective separation of suspended liquid droplets due to the entrainment of liquid droplets with a gas stream from the surface of the plate and the high gas-dynamic resistance of the plate to gas flow.

The technical result of the invention is to increase the efficiency of separation of vaporous and dropping liquid from the gas stream and reducing the gas-dynamic resistance of the separation elements.

The technical result is achieved through the use of a device for separating liquid from a gas stream, including a casing with raw gas inlet nozzles, a purified gas outlet and separated liquid outlet, while at least one separation gas is installed inside the housing between the raw gas inlet and the purified gas outlet an element that includes at least one layer of mesh made of wire with a non-wettable surface, and at least one layer of mesh made of wire with a wettable surface.

Also, the achievement of the technical result is ensured by using the described separation element regardless of the claimed device, for example, as part of devices of a different design.

When using the inventive device with a separation element, the gas flow entering the device’s body passes through the separation element or a combination of separation elements, there is a collision and interaction of liquid droplets with wires with wettable and non-wettable surfaces, which results in the simultaneous separation of water and heavy hydrocarbons, which then diverted through the outlet pipe of the separated liquid, while providing sufficient clearance for the flow of gas through the separation element.

In accordance with the claimed technical solution, the surfaces are classified as wettable and non-wettable based on the values of the contact angle, which is a quantitative characteristic of the process of wetting the surface with liquid and characterizes the intermolecular interaction of the surface of solids with liquids. The value of the wetting angle is the value of the angle that is formed between the tangent drawn to the surface of the liquid-gas phase and the solid surface with a vertex located at the contact point of the three phases, and conditionally measured always inside the liquid phase. For values of this angle less than 90 ° the surfaces are wettable (lyophilic surface), for values of the angle greater than 90 ° they are non-wettable (lyophobic surface). If water is considered as a liquid, surfaces with values of the contact angle less than 90 ° are considered hydrophilic, and with values greater than 90 ° - hydrophobic. In the framework of the present invention, a wettable surface refers to a hydrophilic and oleophobic surface, a non-wettable surface refers to a hydrophobic and oleophilic surface.

It is assumed that suspended water droplets falling on a wire with a non-wettable surface, due to the weak interaction of water with a hydrophobic surface in combination with the gas flow rate, are not retained and transferred by the gas flow, changing the trajectory, which increases the likelihood of collisions and coalescence of droplets in the gas flow . With the coalescence of droplets on a non-wettable surface, their total surface energy decreases, and the released energy can lead to a "bounce" of the newly formed droplet, and, accordingly, to its further transport by the gas stream. As a result of the weak interaction of water with the hydrophobic surface of the wire, a water film does not form, which can lead to a decrease in the cross-sectional area of the separation element available for gas flow due to the removal of water droplets from the non-wettable surface, which ensures a decrease in gas-dynamic resistance compared to the known mesh separation elements.

When suspended water droplets get on the wetted surface, the drop acquires a meniscus shape due to strong interaction with the surface, spreads, forming a liquid film. Due to the strong interaction of water with hydrophilic surfaces, vapor water is captured by wires with a wettable surface. When water accumulates on the surface of a wire with a wettable surface, the size of the droplets increases, the droplets reach a critical size at which they begin to slide along the surface of the wire due to gravitational forces. Thus, wires with a hydrophilic surface serve as channels for the removal of separated water.

In addition to water, the liquid composition in the gas stream also includes suspended droplets and vapors of heavy hydrocarbons. The mechanism of interaction of suspended droplets and the vapor phase of heavy hydrocarbons with oleophilic (non-wettable) and oleophobic (wettable) surfaces is similar to the mechanism of interaction of water with hydrophilic and hydrophobic surfaces. In this case, the thickness of the film of liquid hydrocarbons formed on a wire with a non-wettable surface is much smaller than the thickness of a water film on a wire with a wettable surface under the same conditions, which is associated with the difference in the surface tension of these liquids.

Thus, the device simultaneously provides:

- capture of steam and drop liquid due to the strong interaction of the liquid with the surfaces of the wires (hydrophilic (wettable) for trapping water, oleophilic (non-wettable) for trapping heavy hydrocarbons);

- droplet removal due to weak interaction with a different type of wire surface (with hydrophobic (non-wettable) to remove water droplets, and with oleophobic (wettable) to remove heavy hydrocarbon droplets), which leads to a free flow of gas from wires with a non-wettable surface, t .to. the formation of thick films of water on their surfaces is prevented.

This leads to an increase in the efficiency of separation of vaporous and dropping liquid from the gas stream and to a decrease in the gas-dynamic resistance of the separation elements.

The configuration of the separation element in this case may be different. The wire mesh layer with a non-wettable surface and the wire mesh layer with a wettable surface can be laid together and rolled up so that layers are alternated, or laid together and twisted into a roll, which also ensures the alternation of mesh layers. It is possible to lay several layers of a mesh with a non-wettable surface and several layers of a mesh with a wettable surface to ensure alternation of these layers. In this case, the layers can alternate one through one, one through two or more.

The achievement of the technical result is achieved through the use of a device for separating liquid from a gas stream, including a casing with raw gas inlet nozzles, purified gas outlet and separated liquid outlet, while at least one is installed inside the housing between the raw gas inlet and the purified gas outlet a separation element that includes a mesh made of at least one wire with a non-wettable surface and at least one wire with a wettable surface. Using the above separation element, regardless of the claimed device also ensures the achievement of a technical result.

The wires can be braided together by various weaving methods, for example, by the widely used “cooking surface” method, or they can be tangled together and pressed.

The technical result is also achieved through the use of a device for separating liquid from a gas stream, including a casing with raw gas inlet nozzles, a purified gas outlet and separated liquid outlet, while at least one is installed inside the housing between the raw gas inlet and the purified gas outlet the separation element, which includes a frame with strings stretched in it, made of wires with a non-wettable surface and wires with a wettable surface, while at least one adjacent string made of wire with a non-wettable wire is located next to a string made of wire with a wettable surface surface. The use of the described separation element for separating liquid from a gas stream in the above devices and other devices for separating liquid from a gas stream also ensures the achievement of a technical result.

Moreover, the claimed devices and separation elements can equally effectively be used to separate the liquid from both the horizontal (horizontal gas separator) and the vertical gas stream (vertical gas separator).

The achievement of the technical result is also achieved through the use of a method of separating liquid from a gas stream, according to which a gas stream is supplied through the inlet of the crude gas into the housing of the device according to any of the claimed variants, and it is passed through at least one separation element, while providing separating liquid droplets and draining the liquid through the outlet pipe of the separated liquid.

The proposed mechanism for the interaction of suspended droplets and vapor liquid with the wetted and non-wettable surfaces of the wires from which the separation elements are made is indicated above.

Thus, when passing a gas stream through the claimed device or separation elements, there is a set of processes that provide an increase in the efficiency of separation of steam and droplet liquid from the gas stream and a decrease in the gas-dynamic resistance of the separation elements:

- liquid separation during the collision of suspended droplets with the wires of the separation elements due to which the trajectory of the droplets changes, the probability of their collision increases, while liquid droplets having a density significantly higher than the gas density are separated from the gas flow due to the mass difference;

- adsorption interaction of the vapor phase of water with a wettable (hydrophilic) surface and the vapor of heavy hydrocarbons with a non-wettable (oleophilic) surface of the wires from which the separation elements are made;

- intermolecular interaction of liquid droplets during coalescence;

- self-removal of coarse droplets from the surface of the wire under the action of gravity.

According to the claimed invention, the water contact angle of a wire with a non-wettable surface (hydrophobic) from which the separation elements are made can be from 120 ° to 173 °, preferably from 140 ° to 160 °, most preferably from 142 ° to 150 °, for example 146 °. Surfaces with water contact angles greater than 150 ° are called superhydrophobic. At such values of the contact angle, a very weak interaction of water with the surface of the wire is characteristic, a drop of water on such a surface takes a spherical shape with a minimum contact area with the surface, which provides easier separation of the drop from the surface. If the water contact angle is below 120 °, the interaction of the liquid with the surface will not be weak enough to easily remove droplets from the surface with a gas stream. The upper bound is determined by currently known methods for producing a superhydrophobic surface [Boinovich et al., ACS Appl. Mater. Interfaces, 2015, 7, 19500-19508].

It is preferable that the distance between the wire with a non-wettable surface and the adjacent wire with a wettable surface of which the separation elements are made, in the maximum distance between them, be from 1 mm to 10 mm. This distance provides an effective drainage of the liquid due to the dropping of drops after collision with a wire with a non-wettable surface onto a wire with a wettable surface. A distance of less than 1 mm can lead to an increase in gas-dynamic resistance due to the fact that the thickness of the resulting water film on wires with a wettable surface is about 0.5 mm, an increase in the distance of more than 10 mm does not allow efficient transfer of liquid droplets from a wire with a non-wettable surface to the wire with wettable surface.

The ratio of the total length of a wire with a non-wettable surface to the total length of a wire with a wettable surface in the composition of the separation elements can vary within wide limits (from 0.2: 1 to 20: 1), while at least one wire with a wettable surface can be located adjacent wire with non-wettable surface.

Preferably, the ratio of the total length of the wire with a wettable surface to the total length of the wire with a non-wettable surface in the separation element is 1: 2. This ratio allows you to further increase the efficiency of liquid capture, while ensuring low gas-dynamic resistance of the separation elements.

In the framework of this invention, a wire with a non-wettable surface can be obtained by any known method. The surface of such a wire may be roughened. It is known that an increase in the roughness of a hydrophobic surface leads to an increase in the values of the contact angle due to an increase in the area of contact of the liquid with the surface. A wire with a non-wettable surface, from which the separation element is made, can be made of metal, while a hydrophobic coating is applied to its surface, or from any other materials suitable for use in gas separators. In particular, the non-wettable surface of the wire can be obtained by applying an inorganic coating to the surface of a metal wire, consisting of dispersed powder particles ranging in size from 1 nm to 100 μm, followed by chemical treatment of the obtained surface with a modifying agent, which imparts hydrophobic properties to the surface of the obtained coating. As a material for an inorganic coating, both simple and complex chemicals can be used, for which it is possible to choose a modifying agent, which gives them the ability to not be wetted by the separated liquid. For example, in the case of separation of water from a gas stream, non-metal and transition metal oxides, in particular, silicon oxide, aluminum oxide, titanium oxide, can be used as the material for the inorganic coating. As such modifying agent, substituted silanes (e.g., trimethylchlorosilane, dimethyldichlorosilane, trimethoxysilanes with a hydrocarbon fourth substituent, triethoxysilanes with a hydrocarbon fourth substituent, trimethoxysilanes with a perfluorinated hydrocarbon fourth substituent, triethoxysilanes with a perfluorinated hydrocarbon fourth substituent) can be used as such a modifying agent. Surfaces of this kind are characterized by a hierarchical structure, i.e. the presence of micron-sized roughnesses, the surface of which, in turn, has nanometer-sized roughnesses. Such features of the relief lead to a decrease in the area of contact between the liquid and the surface due to the implementation of the Cassie-Baxter wetting mode, and are characterized by high contact wetting angles. The coating can be applied to the surface of the wire both before it is included in the composition of the mesh or separation element, and as part of the mesh, which is then used to make the separation element.

The wires with a wettable surface from which the separation element is made can be made of metal, modified by any known method of producing well-wettable surfaces, in particular, by treating a metal wire with oxygen plasma, etching the surface of a metal wire in inorganic or organic acids, or by applying a layer of insoluble in water, a polyelectrolyte (a polymer containing functional groups that form cations or anions when interacting with water), or can be made of other materials suitable for use in gas separators, for example, from a polymer filament having an insignificant coefficient of linear expansion.

For the manufacture of nets, both straight and pre-corrugated wires can be used.

A device for separating liquid from a gas stream may comprise at least one heat exchange element installed either between the raw gas inlet pipe and the separation element, or between the separation element and the purified gas outlet, or inside the separation element. The heat exchange element is cooled by circulation of the refrigerant and has a temperature below the temperature of the incoming gas stream.

In the case of installing a heat exchange element between the raw gas inlet pipe and the separation element, the gas stream contacts the heat exchange element, on which condensation of liquid vapor from the gas stream occurs, growth, as well as coalescence of droplets suspended in the gas stream, partial separation of large drops due to gravity is also possible then the gas stream with coarse suspended droplets of liquid interacts with the separation element, on which the liquid droplets are separated from the gas stream, the separated liquid is discharged through the outlet of the separated liquid, and the purified gas is discharged through the outlet of the purified gas.

When a heat-exchange element is installed inside the separation element, the cold surface of the heat-exchange element contacts the surface of the separation element and cools it, which leads not only to a cooling of the gas flow upon contact with the heat-exchange element as described above, but also to cooling of the separation element itself, which provides additional steam condensation liquid on the surface of the separation element, enlargement of droplets, which accelerates the process of separation of the liquid from the gas stream.

In the case of installing a heat exchange element between the separation element and the outlet of the purified gas outlet, in one embodiment, additional condensation is provided on the surface of the heat exchange element due to cooling of the vapor liquid and enlargement of liquid droplets that did not separate when the gas stream passed through the separation element; in another embodiment, after passing through the separation elements, the stream of purified gas interacts with the hot heat-exchange element, which leads to an increase in the temperature of the purified gas, reduces its saturation with liquid vapor and thereby further eliminates the formation of new drops of liquid in the stream of purified gas sent to the consumer after the gas separator.

The surface of the cold heat exchange element can be hydrophobic, which helps prevent the formation of a liquid film on its surface, increases the efficiency of heat removal due to condensation in the drip mode, and also intensifies the condensation of liquid from the gas stream. The hydrophobic surface properties of the cold heat exchanger also provide resistance to hydrate deposits on the surface of the heat exchange element. In this case, the resulting hydrate nuclei (particles) are not retained on the surface, are carried away by the gas flow and decompose, forming a droplet liquid, which is separated by a separation element located between the heat exchange element and the outlet of the purified gas.

As heat exchange elements, heat exchangers of any known types can be used (evaporator, radiator, condenser, recuperator, microheat exchanger, cooling tower, air heater, economizer), or any type of cooling section with an external refrigeration cycle.

To ensure precondensation of the vapor and droplet liquid, the gas stream can be pre-cooled before being fed to the device housing for separating the liquid from the gas stream.

The gas stream can also be divided into two streams, one of which is preliminarily directed to cooling and then fed into the casing of the device for separating liquid from the gas stream simultaneously with the second (uncooled) gas stream. As a result of mixing two gas streams with different temperatures, the gas is cooled and the condensation process of steam and droplet liquid in the gas stream is intensified.

A device for separating liquid from a gas stream may contain, between the separation element and the outlet of the purified gas outlet, an additional separation element consisting of a mesh made of wire with a wettable surface, this allows additionally coalescing and separating water droplets previously coalesced but not separated from the gas stream on the first separation element.

The device for separating liquid from the gas stream may further comprise between the separation element and the outlet of the purified gas at least one centrifugal separation element, made, for example, in the form of minicyclones. Centrifugal separation elements provide for the separation of coarse liquid droplets that did not separate when passing through a separation element made of wire with a wettable surface and wire with a non-wettable surface.

In the device for separating liquid from the gas stream between the inlet pipe of the raw gas and the separation element can be installed inlet distribution element. The inlet distribution element ensures uniform distribution of the gas flow over the separator cross section, as well as the reception of liquid plugs in the separator volume, the size of which is much larger than the size of the liquid particles suspended in the gas flow, and their rapid separation from the gas flow. In particular, a wedge-shaped or tangential device can act as an input distribution element. The use of, for example, an inlet distribution element with a tangential inlet pipe leads to the separation of the largest drops of liquid suspended in the gas stream under the action of centrifugal forces before the gas stream passes through the separation elements.

A device for separating liquid from a gas stream may contain, between the raw gas inlet pipe and the separation element, an additional separation element made in the form of a louvered (plate) droplet eliminator, which is designed to separate liquid droplets suspended in the gas stream from 10 μm to 40 μm in size. The separation of liquid droplets using louvre droplet eliminators occurs due to the difference in the density of the liquid and gas by directing the gas flow along a curved path, as a result of which liquid droplets having a density significantly higher than the gas density are separated from the gas stream.

The use of an inlet distribution element and a plate (louvre) separation element allows preliminary separation of large liquid droplets from a gas stream, and then, on a separation element made of wire with a non-wettable surface and a wire with a wettable surface, to separate smaller suspended droplets and vapor liquid.

Due to the fact that each type of separation elements in a device for separating liquid from a gas stream is characterized by a different performance, droplet size, gas-dynamic resistance, a device for separating liquid from a gas stream can include various combinations of a separation element made of wire with a wettable surface and wire with non-wettable surface, with additional separation, heat transfer or other elements for separating liquid from the gas stream.

Due to the fact that any separation elements require periodic maintenance, the device for separating liquid from the gas stream may include a hole or pipe for installing and removing the separation elements.

The invention is illustrated by the following graphic materials.

Figure 1 as an example implementation of the present invention schematically shows the design of a device for separating liquid from a gas stream, where:

1 - device body;

2 - pipe inlet of the crude gas;

3 - outlet pipe for purified gas;

4 - outlet pipe of the separated liquid;

5 - separation element.

The figure 2 shows the relative position of the layers of the mesh made of wire with a non-wettable surface, and the layer of mesh made of wire with a wettable surface.

Figure 3 shows the configuration when the wire mesh layers with a non-wettable surface and the wire mesh layer with a wettable surface are stacked and rolled up.

Figure 4 shows the configuration when the wire mesh layers with a non-wettable surface and the wire mesh layer with a wettable surface are laid together and twisted into a roll, where:

6 - mesh made of wire with a non-wettable surface;

7 - mesh made of wire with wetted surface.

Figures 5-7 show the dependence of the changes in the separation coefficient with an increase in the equivalent gas flow rate when using devices with various types of separation elements, where:

8 shows the dependence of the values of the separation coefficient on the equivalent gas flow rate when using a device for separating liquid from a gas stream containing a separation element comprising one layer of a mesh made of wire with a wettable surface and two layers of a mesh made of wire with a non-wettable surface;

9 shows the dependence of the values of the separation coefficient on the equivalent gas flow rate when using a device for separating liquid from a gas stream containing a separation element including layers of a mesh made of wire with a wettable surface;

10 - dependence of the values of the separation coefficient on the equivalent gas flow rate when using a device for separating liquid from a gas stream containing a separation element comprising one layer of a mesh made of wire with a wettable surface and two layers of a mesh made of wire with a non-wettable surface, between the specified separation element and the outlet pipe of the purified gas an additional separation element is installed, the mesh layers of which are made of wire with a wettable surface;

11 - dependence of the values of the separation coefficient on the equivalent gas flow rate when using a device for separating liquid from a gas stream containing a separation element, including layers of a mesh made of wire with a wettable surface, while an additional separation is installed between the specified separation element and the outlet of the purified gas an element whose mesh layers are made of wire with a wettable surface;

12 - dependence of the values of the separation coefficient on the equivalent gas flow rate when using a device for separating liquid from a gas stream containing a separation element comprising one layer of a mesh made of wire with a wettable surface and two layers of a mesh made of wire with a non-wettable surface, between the inlet of the crude gas and the specified separation element, a heat exchange element is installed on the surface of which a hydrophobic coating is applied;

13 - dependence of the values of the separation coefficient on the equivalent gas flow rate when using a device for separating liquid from a gas stream containing a separation element comprising one layer of a mesh made of wire with a wettable surface and two layers of a mesh made of wire with a non-wettable surface, a heat exchange element is installed between the raw gas inlet and said separation element;

14 shows the dependence of the values of the separation coefficient on the equivalent gas flow rate when using a device for separating liquid from a gas stream containing a separation element including layers of a mesh made of wire with a wettable surface, and a heat-exchange element is installed between the inlet of the raw gas and the specified separation element.

A device for separating liquid from a gas stream includes a housing 1 with nozzles for the inlet of the crude gas 2, the outlet of the purified gas 3 and the outlet of the separated liquid 4, at least one separation element 5 is installed inside the housing between the nozzle of the crude gas inlet and the outlet of the purified gas, 5 which includes at least one layer of mesh made of wire with a non-wettable surface, and at least one layer of mesh made of wire with a wettable surface. In one embodiment, the separation element includes a mesh made of at least one wire with a non-wettable surface and at least one wire with a wettable surface. In another embodiment, the separation element includes a frame with strings stretched in it, made of wires with a non-wettable surface and wires with a wettable surface, while at least one adjacent string made of wire with a wetted surface is located next to a string made of wire with a wettable surface non-wettable surface.

The following examples serve to illustrate the invention, but should not be construed as limiting the invention.

Example 1. The efficiency of separating liquid from a gas stream was evaluated by comparing the test results of using the inventive device for separating liquid from a gas stream, the separation element of which includes a mesh made of one layer of wire with a wettable surface and two layers of wire with a non-wettable surface, and a device the element of which includes a mesh made of wire with a wettable surface. The wire mesh with non-wettable surface is a wire mesh made of stainless steel wire with a hydrophobic coating. For hydrophobic coating, the mesh is processed in the presence of a witness coupon. The grid is washed twice with acetone and ethanol to clean the surface (degreasing), then wound into a roll with a diameter of 220-240 mm (the length of the grid in a roll was about 100 m), placed in a reactor and filled with ethanol at the rate of about 4.5 l of ethanol per 100 m the grid. Next, tetraethoxysilane (at a rate of about 32.6 ml per 100 m of a grid) and hexadecyltrimethoxysilane (at a rate of about 21.1 ml per 100 m of a grid) are added sequentially, after which a 25% aqueous ammonia solution (at a rate of 810 ml per 100 m net). These operations are carried out with vigorous stirring in the reactor by circulating a liquid using a peristaltic pump. After adding all the components, the reaction mixture is heated to 60 ° C and held for an hour at this temperature. After separating the treated mesh from the reaction mixture and washing with distilled water, a silanized surface mesh is obtained, which is dried at a temperature of 100 ° C. for 5 hours. The degree of surface hydrophobization is assessed using a stainless steel witness coupon. The value of the water contact angle in this case was 150 °, which significantly exceeds the contact angle on any smooth substrates (for example, polytetrafluoroethylene has a contact angle of 114 ° -118 °) and indicates the formation of a superhydrophobic coating on stainless steel. After processing, the mesh is corrugated with a corrugation step of about 2 mm.

A wire mesh made of stainless steel 84 mm wide, corrugated with a corrugation step of 2 mm, degreased by successive washing in acetone and ethanol was used as a wire mesh with a wettable surface.

Separation elements were assembled from the grids prepared by the indicated methods, the density of the grid laying was about 300 kg / m ³ . The first separation element includes three alternating layers of mesh (wire with a non-wettable surface / wire with a wettable surface / wire with a non-wettable surface) laid as shown in figure 3. The second separation element includes a mesh made of wire with a wettable surface, similar to size of the first separation element.

The first separation element is installed in a device including a housing with nozzles for the inlet of the crude gas, the outlet of the purified gas and the outlet of the separated liquid, horizontal design. A gas stream is passed through the device and the efficiency is estimated by the average values of the droplet liquid content at the inlet and outlet of the gas separator. From the obtained values, it is determined how the separation coefficient changes depending on the change in the equivalent gas flow rate.

The separation coefficient is determined by the formula:

where V _c is the volume of fluid in the drainage, ml; Q _f - nozzle productivity, ml / min; t _e is the experiment time.

The equivalent gas flow rate is determined by the formula:

where Q _g - gas flow, m ³ / h (n.o.); S is the cross-sectional area of the separation nozzle, m ² ; 3600 - conversion factor to obtain the speed dimension m / s.

Similarly, the efficiency of separating liquid from a gas stream passing through a device in which a second separation element was installed, including mesh layers made of wire with a wettable surface, was evaluated.

The results are presented in figure 5, which shows that for curve 9 there is a sharp drop in the values of the separation coefficient with an increase in the equivalent gas flow rate compared to curve 8.

Example 2. The efficiency of separating liquid from a gas stream was evaluated using the inventive device for separating liquid from a vertical gas stream, the separation element of which includes a grid made of one layer of wire with a wettable surface and two layers of wire with a non-wettable surface, and a device whose separation element is includes a grid made of wire with a wettable surface, while between the separation element and the outlet of the purified gas outlet of both devices an additional separation element is installed, including a grid made of wire with a wettable surface.

The preparation of grids and the assembly of separation elements was carried out similarly to those indicated in example 1.

To compare the efficiency of liquid separation, a gas stream is passed through these devices and the change in the values of the separation coefficient is evaluated depending on the change in the equivalent gas flow rate according to formulas (1) and (2).

The test results obtained are presented in figure 6, which shows that for curve 11 there is a sharp drop in the values of the separation coefficient with an increase in the equivalent gas flow rate compared to curve 10.

An analysis of the data obtained in both examples shows that when using a mesh composed of only a wire with a wettable surface as a part of the separation element (curves 9 and 11), a sharp drop in the separation coefficient of the dropping liquid is observed with an increase in the equivalent gas velocity. When using a mesh made of a wire with a wettable surface and a wire with a non-wettable surface as a part of the separation element, the drop in the separation coefficient of droplet liquid decreases more gently with an increase in the equivalent gas velocity (curves 8 and 10), which indicates that the drop liquid is separated from gas flow is more efficient.

Example 3. The efficiency of separation of the liquid from the gas stream was evaluated by comparing the changes in the values of the separation coefficient depending on the change in the equivalent gas flow rate calculated by formulas (1) and (2).

The first device includes a combination of a heat exchange element and a separation element containing two layers of a mesh made of wire with a non-wettable surface, and a mesh layer made of wire with a wettable surface, the layers being laid as shown in figure 3.

The second device includes a combination of a heat-exchange element, on the surface of which a hydrophobic coating is applied, and a separation element containing two layers of a mesh made of wire with a non-wettable surface, and a mesh layer made of wire with a wettable surface, the layers being laid as shown in figure 3 .

The third device includes a combination of a heat exchange element and a separation element containing a mesh made of wire with a wettable surface.

The preparation of grids and the assembly of separation elements is similar to those indicated in example 1. The application of a hydrophobic coating on the surface of the heat exchange element was carried out similarly to the process of hydrophobization of the surface of the grid in example 1.

The obtained test results are shown in figure 7. From the presented dependencies it is seen that the use of a separating element containing mesh layers made of wires with wettable and non-wettable surfaces as a part of the device for separating liquid from the gas stream (curve 13) leads to an increase in the values of the separation coefficient compared with a device whose separation element contains a grid made only of wire with a wettable surface (curve 14). Hydrophobization of the surface of the heat exchange element also leads to an increase in the values of the separation coefficient (curve 12).

An increase in the values of the separation coefficient of the claimed devices and separation elements compared to the values of the separation coefficient when using devices whose separation elements include a mesh made of wire with a wettable surface, with an increase in the equivalent gas flow rate allows us to conclude that the efficiency of liquid separation from the gas stream is increased and reducing the gas-dynamic resistance of the separation elements to the gas flow.

Due to the fact that the mechanism of interaction of the droplet and steam liquid with wettable and non-wettable surfaces is similar for separation elements that contain layers of nets made of wires with wettable and non-wettable surfaces, and for separation elements that include a mesh made of wire with wettable surface and wire with a non-wettable surface, or a frame with strings stretched in it made of wires with a wettable and non-wettable surface, the presented examples confirm the achievement of the technical result when using the claimed options for separation elements for separating liquid from a gas stream and the claimed variants of devices for separating liquid from the gas stream.

Thus, the claimed technical solution provides an increase in the efficiency of separation of vaporous and dropping liquid from the gas stream and a decrease in the gas-dynamic resistance of the separation elements, which, in turn, leads to an improvement in heat and mass transfer between the gas stream and the separation elements.

Claims (34)

1. A device for separating liquid from a gas stream, including a housing with nozzles for the inlet of the crude gas, outlet of the purified gas and the outlet of the separated liquid, while at least one separation element is installed inside the housing between the nozzle of the crude gas inlet and the outlet of the purified gas, which includes at least one layer of mesh made of wire with a wettable surface, and at least one layer of mesh made of wire with a wettable surface. 2. A device for separating liquid from a gas stream according to claim 1, wherein the grid layers made of wire with a non-wettable surface and the mesh layers made of wire with a wettable surface are alternated. 3. A device for separating liquid from a gas stream according to claim 1, wherein at least one layer of the mesh made of wire with a non-wettable surface, and at least one layer of the mesh made of wire with a wettable surface, is laid in a roll. 4. A device for separating liquid from a gas stream, including a housing with nozzles for the inlet of the crude gas, outlet of the purified gas and the outlet of the separated liquid, while at least one separation element is installed inside the housing between the nozzle of the crude gas inlet and the outlet of the purified gas, which includes a mesh made of at least one wire with a non-wettable surface and at least one wire with a wettable surface. 5. A device for separating liquid from a gas stream according to claim 4, in which a wire with a non-wettable surface and a wire with a wettable surface are woven together. 6. A device for separating a liquid from a gas stream according to claim 4, wherein the wire with a non-wettable surface and a wire with a wettable surface are tangled and pressed together. 7. A device for separating liquid from a gas stream, including a housing with nozzles for the inlet of the crude gas, outlet of the purified gas and the outlet of the separated liquid, while at least one separation element is installed inside the housing between the nozzle of the crude gas inlet and the outlet of the purified gas, which includes a frame with strings stretched in it made of wires with a non-wettable surface and wires with a wettable surface, while at least one adjacent string made of wire with a non-wettable surface is located next to a string made of wire with a wettable surface. 8. A device for separating liquid from a gas stream according to any one of paragraphs. 1, 4, 7, in which the wetting angle of water wire with a non-wettable surface is from 120 ° to 173 °. 9. A device for separating liquid from a gas stream according to any one of paragraphs. 1, 4, 7, in which the distance between the wire with a non-wettable surface and the adjacent wire with a wettable surface at the maximum distance between them is from 1 mm to 10 mm. 10. A device for separating liquid from a gas stream according to any one of paragraphs. 1, 4, 7, in which the ratio of the total length of the wire with a wettable surface to the total length of the wire with a non-wettable surface in the separation element is 1: 2. 11. A device for separating liquid from a gas stream according to any one of paragraphs. 1, 4, 7, in which the non-wettable surface of the wire is roughened. 12. A device for separating liquid from a gas stream according to any one of paragraphs. 1, 4, 7, in which a wire with a non-wettable surface is made of metal, while a hydrophobic coating is applied to its surface. 13. A device for separating liquid from a gas stream according to any one of paragraphs. 1, 4, 7, in which a wettable wire is made of metal. 14. A device for separating liquid from a gas stream according to any one of paragraphs. 1, 4, 7, which contains at least one heat exchange element installed in the housing between the raw gas inlet pipe and the separation element. 15. A device for separating liquid from a gas stream according to any one of paragraphs. 1, 4, 7, which contains at least one heat exchange element mounted in the housing between the separation element and the outlet pipe of the purified gas. 16. A device for separating liquid from a gas stream according to any one of paragraphs. 1, 4, 7, which contains at least one heat exchange element mounted inside the separation element to ensure contact between the surface of the heat exchange element and the separation element. 17. A device for separating liquid from a gas stream according to any one of paragraphs. 1, 4, 7, in which at least one additional separation element is installed between the separation element and the outlet of the purified gas, which includes at least one mesh made of wire with a wettable surface, or a frame with strings stretched in it made of wetted wire. 18. A device for separating liquid from a gas stream according to any one of paragraphs. 1, 4, 7, in which at least one centrifugal separation element is installed between the separation element and the outlet of the purified gas. 19. A device for separating liquid from a gas stream according to any one of paragraphs. 1, 4, 7, which comprises an inlet distribution element installed in front of the separation element. 20. A device for separating liquid from a gas stream according to any one of paragraphs. 1, 4, 7, in which between the raw gas inlet pipe and the separation element an additional separation element is installed comprising a louvre droplet eliminator. 21. The method of separating liquid from a gas stream, according to which into the housing of a device made according to any one of paragraphs. 1-20, a gas stream is supplied through the raw gas inlet pipe and passed through at least one separation element, while separating liquid droplets and draining the liquid through the outlet pipe of the separated liquid. 22. A separation element for separating liquid from a gas stream, which includes at least one layer of a mesh made of wire with a non-wettable surface, and at least one layer of a mesh made of wire with a wettable surface. 23. The separation element for separating liquid from a gas stream according to claim 22, wherein the layers of the mesh made of wire with a non-wettable surface and the layers of the mesh made of wire with a wettable surface are alternated. 24. A separation element for separating liquid from a gas stream according to claim 22, wherein at least one mesh layer made of wire with a non-wettable surface and at least one mesh layer made of wire with a wettable surface is laid on a roll. 25. A separation element for separating liquid from a gas stream, which includes a grid made of at least one wire with a non-wettable surface and at least one wire with a wettable surface. 26. A separation element for separating a liquid from a gas stream according to claim 25, wherein the wire with a non-wettable surface and a wire with a wettable surface are woven together. 27. A separation element for separating a liquid from a gas stream according to claim 25, wherein the wire with a non-wettable surface and a wire with a wettable surface are tangled and pressed together. 28. A separation element for separating liquid from a gas stream, which includes a frame with strings stretched in it, made of wires with a non-wettable surface and wires with a wettable surface, while at least one string is located next to a string made of wire with a wettable surface adjacent string made of wire with a non-wettable surface. 29. The separation element for separating liquid from a gas stream according to any one of paragraphs. 22, 25, 28, in which the water contact angle of a wire with a non-wettable surface is from 120 ° to 173 °. 30. The separation element for separating liquid from a gas stream according to any one of paragraphs. 22, 25, 28, in which the distance between the wire with a non-wettable surface and the adjacent wire with a wettable surface at the maximum distance between them is from 1 mm to 10 mm. 31. The separation element for separating liquid from a gas stream according to any one of paragraphs. 22, 25, 28, in which the ratio of the total length of the wire with a wettable surface to the total length of the wire with a non-wettable surface in the separation element is 1: 2. 32. The separation element for separating liquid from a gas stream according to any one of paragraphs. 22, 25, 28, in which the non-wettable surface of the wire is roughened. 33. The separation element for separating liquid from a gas stream according to any one of paragraphs. 22, 25, 28, in which the wire with a non-wettable surface is made of metal, while a hydrophobic coating is applied to its surface. 34. The separation element for separating liquid from a gas stream according to any one of paragraphs. 22, 25, 28, in which a wettable wire is made of metal.

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