CN113308283A - Low-temperature separation device and separation method - Google Patents

Abstract

The invention provides a low-temperature separation device and a separation method, wherein the low-temperature separation device comprises: the separation container is internally provided with a first-stage separation chamber, a second-stage separation chamber and a third-stage separation chamber which are communicated with each other in sequence along the circulation direction of the natural gas; the natural gas separator comprises a coalescer and a baffle separator which are sequentially arranged in the natural gas flowing direction, and the natural gas is used for sequentially flowing through the inertial separator, the centrifugal separator, the coalescer and the baffle separator so as to separate a gas phase and a liquid phase in the natural gas. The low-temperature separation device and the separation method provided by the embodiment of the invention realize the purpose of gas-liquid separation of the wax-containing natural gas, and solve the technical problem of poor separation performance when the existing vertical separator is used for treating the wax-containing natural gas.

Description

Low-temperature separation device and separation method

Technical Field

The invention relates to the technical field of gas-liquid separation, in particular to a low-temperature separation device and a separation method suitable for wax-containing natural gas.

Background

Natural gas produced from natural gas fields contains certain impurities, such as hydrocarbons, alcohols and water, due to natural conditions. These impurities in natural gas have an adverse effect on both the use and transport of the natural gas, and therefore, the impurities in natural gas produced by natural gas field mining must be removed.

At present, natural gas is processed by a low-temperature (i.e. at a temperature of-15 ℃ or below) process, such as low-temperature sedimentation, so that impurities included in the natural gas become liquid, and then the liquid is separated from the natural gas by a gas-liquid separation method in the low-temperature process. The gas-liquid separator in the low-temperature natural gas treatment process generally adopts a vertical separator, and a vane distributor, a coalescer and a cyclone are generally arranged in the vertical separator along the flowing direction of the natural gas. The vertical separator is used for uniformly distributing natural gas by the blade distributor, then the coalescer is used for accumulating small condensed liquid drops mixed in the natural gas to form large liquid drops, finally, the cyclone is used for gas-liquid separation, the separated liquid is dropped to the liquid storage space at the lower end of the vertical separator through the downcomer, and the separated gas enters a subsequent pipeline.

However, when the vertical separator is used for processing natural gas with high wax content, the wax precipitated by the vertical separator has high viscosity, and the precipitated high-viscosity wax can be attached to the coalescent wire mesh in the coalescer along with the increase of production time, so that the coalescent wire mesh is blocked, the pressure drop of the gas through the coalescer is gradually increased, the separated liquid cannot pass through the coalescent wire mesh for liquid descending, in severe cases, a downcomer can be blocked, the separation performance of the vertical separator is seriously influenced, and the separation performance of the vertical separator on the natural gas with high wax content is poor.

Disclosure of Invention

The invention provides a low-temperature separation device and a separation method, which solve the technical problem of poor separation performance when the conventional vertical separator is used for treating natural gas with high wax content.

In a first aspect, the invention provides a low-temperature separation device, which is suitable for gas-liquid separation of wax-containing natural gas, and comprises a separation container, wherein a first-stage separation chamber, a second-stage separation chamber and a third-stage separation chamber which are communicated with each other are sequentially arranged in the separation container along the circulation direction of the natural gas;

the separator assembly comprises a coalescer and a baffle separator which are sequentially arranged in the flowing direction of natural gas, and the natural gas is used for sequentially flowing through the inertial separator, the centrifugal separator, the coalescer and the baffle separator so as to separate gas phase and liquid phase in the natural gas.

The cryogenic separation device as described above, optionally, the inertial separator includes a blocking plate and a plurality of blocking members, and the plurality of blocking members are disposed on one or both surfaces of the blocking plate along the natural gas flow direction;

the barriers are arranged on the group of baffles in a staggered mode according to preset line spacing and column spacing and used for separating liquid phase from gas phase in the natural gas.

Optionally, the blocking member is a bent structure, and the blocking member includes an air inlet end, a guiding portion, and a bent end disposed opposite to the air inlet end and blocking the natural gas; the guide portion is connected between the air inlet end and the bent end and used for guiding the natural gas to circulate between the air inlet end and the bent end.

In the cryogenic separation device, optionally, the width of the barrier decreases gradually from the air inlet end to the bent end.

Optionally, two sides of the air inlet end are respectively provided with a bending part bending towards the inside of the barrier, and the bending part is used for blocking the natural gas rebounded to the air inlet end after being blocked by the bending end.

In the cryogenic separation device, optionally, a sprayer is arranged in the second-stage separation chamber, and the sprayer is used for washing the blocked wax on the centrifugal separator.

The cryogenic separation device of any one of the above claims, optionally, the baffle separator is a corrugated plate separator provided at the gas outlet end of the coalescer, the corrugated plate separator is used for separating the liquid phase formed by the coalescence of the coalescer from the gas phase in the natural gas, and discharging the gas phase from the separation vessel.

Optionally, the separation container is provided with an air inlet cavity, the air inlet cavity is located on a side of the first-stage separation chamber away from the second-stage separation chamber, the air inlet cavity is provided with an air inlet and a distributor communicated with the air inlet, and the distributor is obliquely arranged in the separation container and opposite to the inertial separator.

The cryogenic separation device according to any one of the preceding claims, optionally, further comprising a reservoir located at the bottom of the separation vessel and communicating with the separation vessel, wherein the reservoir comprises three independent reservoir chambers;

the three independent liquid storage chambers comprise a first liquid storage chamber communicated with the first-stage separation chamber, a third liquid storage chamber communicated with the second-stage separation chamber, and a third liquid storage chamber communicated with the third-stage separation chamber.

In a second aspect, the present invention provides a separation process suitable for waxy natural gas comprising the steps of:

enabling the natural gas to enter an inertial separator in a separation container, and carrying out first-stage gas-liquid separation on the natural gas through the inertial separator;

the natural gas subjected to the first stage of gas-liquid separation enters a centrifugal separator in the separation container, and the natural gas is subjected to second stage gas-liquid separation through the centrifugal separator;

the natural gas subjected to the second-stage gas-liquid separation enters a separator component in the separation container, a liquid phase in the natural gas is coalesced through a coalescer in the separator component, and then the natural gas is subjected to third-stage gas-liquid separation to obtain a gas phase in the natural gas;

discharging the gas phase from the separation vessel;

and respectively collecting liquid phases obtained after the first-stage gas-liquid separation, the second-stage gas-liquid separation and the third-stage gas-liquid separation.

The invention provides a low-temperature separation device and a separation method, wherein an inertial separator, a centrifugal separator and a separator component are arranged in a separation container, and the impurities included in the wax-containing natural gas are converted into liquid state because the wax-containing natural gas is treated by a low-temperature treatment process before entering the low-temperature separation device; then, carrying out secondary gas-liquid separation on the natural gas through a centrifugal separator, and separating light hydrocarbon, a small amount of alcohol and water in a liquid state in the natural gas; and finally, performing third gas-liquid separation on the natural gas through the separator component, wherein on the basis of realizing the gas-liquid separation of the natural gas, the wax is separated during the first gas-liquid separation and the second gas-liquid separation, so that only a small amount of light hydrocarbon, a small amount of alcohol and water are contained in the natural gas entering the coalescer, the risk that the coalescing screen in the coalescer is blocked by the wax is avoided, and the coalescing screen in the coalescer can not be blocked while the gas-liquid separation of the natural gas is realized. Therefore, the low-temperature separation device and the separation method provided by the embodiment realize the purpose of gas-liquid separation of the wax-containing natural gas, and solve the technical problem of poor separation performance of the existing vertical separator when the existing vertical separator is used for treating the high-wax-containing natural gas.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic diagram of a prior art vertical separator;

FIG. 2 is a schematic structural diagram of a cryogenic separation plant according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of an inertial separator according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a blocking member according to an embodiment of the present invention;

FIG. 5 is a schematic view showing the structure of a centrifugal separator according to a first embodiment of the present invention;

FIG. 6 is a schematic structural view of a baffle separator provided in accordance with an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a wave flap according to an embodiment of the present invention;

fig. 8 is a schematic flow chart of a separation method according to a second embodiment of the present invention.

Description of reference numerals:

a separation vessel-1; an air inlet cavity-11; a first stage separation chamber-12; inertial separator-121; barrier panel-1211; a barrier-1212; inlet end-12121; lead-12122; bent end-12123; bending part-12124; a second stage separation chamber-13; a centrifugal separator-131; -a swirl element-1311; -132, a sprayer; a third stage separation chamber-14; separator assembly-141; a coalescer-1411; baffle separators-1412; a corrugated plate-14121; an air inlet-15; an air outlet-16; distributor-17; a service hole-18; a liquid storage container-2; a first reservoir chamber-21; a first outlet port-211; a second reservoir chamber-22; a second outlet port-221; a third reservoir chamber-23; a third outlet-231; a first communicating pipe-3; a second communicating tube-4; a third communicating pipe-5; an inner insertion tube-6; adjusting a valve-7; a swirler-8; a downcomer-9; a blade distributor-10.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As described in the background art, the gas-liquid separator in the cryogenic natural gas treatment process generally adopts a vertical separator, as shown in fig. 1, after the natural gas is uniformly distributed by the blade distributor 10, the gas rises through the coalescence wire mesh in the coalescer 1411 to accumulate small coalesced liquid drops entrained in the natural gas into large liquid drops, and then the large liquid drops are subjected to gas-liquid separation through the cyclone element and the separation wire mesh in the cyclone 8, the separated liquid drops to the liquid storage space at the lower end of the vertical separator through the downcomer 9, and the separated gas enters the subsequent pipeline. In the vertical separator, the pressure drop of the coalescent screen is not too large to ensure that the separated liquid passes through the downcomer to the liquid storage space at the lower end, however, when the vertical separator is used for treating high-wax natural gas, due to the high viscosity of the wax precipitated by the vertical separator, the precipitated high-viscosity wax can be attached to the coalescent screen in the coalescer 1411 along with the increase of production time, so that the coalescent screen is blocked, the pressure drop of the gas passing through the coalescer 1411 is gradually increased, and the separated liquid cannot pass through the coalescent screen to be subjected to liquid precipitation and liquid precipitation. Under severe conditions, the liquid at the bottom rises through the downcomer 9 under the action of pressure difference, gas-liquid separation fails, the separation performance of the vertical separator is seriously affected, and the separation performance of the vertical separator on natural gas with high wax content is poor.

It should be noted that the natural gas with high wax content in the present embodiment refers to the wax-containing natural gas whose wax content in the natural gas affects the vertical separator in the conventional vertical separator. In this embodiment, the wax content in the high wax content natural gas is not further limited.

In view of the above, the present invention provides a low temperature separation apparatus and a separation method, so as to solve the technical problem of poor separation performance when the existing vertical separator is used for treating natural gas with high wax content.

Example one

Fig. 2 is a schematic structural view of a cryogenic separator according to a first embodiment of the present invention, fig. 3 is a schematic structural view of an inertial separator according to a first embodiment of the present invention, fig. 4 is a schematic structural view of a baffle according to a first embodiment of the present invention, fig. 5 is a schematic structural view of a centrifugal separator according to a first embodiment of the present invention, fig. 6 is a schematic structural view of a baffle separator according to a first embodiment of the present invention, and fig. 7 is a schematic structural view of a corrugated plate according to a first embodiment of the present invention.

Referring to fig. 2 to 7, an embodiment of the present invention provides a cryogenic separation device, which is suitable for gas-liquid separation of wax-containing natural gas, and includes a separation container 1, where a first-stage separation chamber 12, a second-stage separation chamber 13, and a third-stage separation chamber 14, which are communicated with each other, are sequentially arranged in the separation container 1 along a flowing direction of the natural gas, so that the natural gas sequentially passes through the first-stage separation chamber 12, the second-stage separation chamber 13, and the third-stage separation chamber 14; wherein, the first stage separation chamber 12 is internally provided with an inertial separator 121, the second stage separation chamber 13 is internally provided with a centrifugal separator 131, and the third stage separation chamber 14 is internally provided with a separator assembly 141, wherein the separator assembly 141 comprises a coalescer 1411 and a baffle separator 1412 which are sequentially arranged along the circulation direction of the natural gas, and the natural gas is used for sequentially flowing through the inertial separator 121, the centrifugal separator 131, the coalescer 1411 and the baffle separator 1412 so as to separate gas phase and liquid phase in the natural gas.

In this embodiment, before the waxy natural gas is processed by the cryogenic separation device, the waxy natural gas is processed by a cryogenic treatment process to change impurities in the waxy natural gas into a liquid state. Wherein the low-temperature treatment process is generally understood as a treatment performed at a temperature of-15 ℃ or less, such as low-temperature precipitation and the like. Accordingly, the cryogenic separation device in this embodiment belongs to a separation process in a cryogenic treatment process, and therefore, the treatment temperature of the cryogenic separation device in this embodiment should be less than or equal to minus 15 ℃, that is, the cryogenic temperature is less than or equal to minus 15 ℃.

Specifically, referring to fig. 2, the natural gas first collides with the inertial separator 121 through the inertial separator 121, and heavy liquid phase substances (such as wax) in the natural gas are separated from the gas phase, so that the first gas-liquid separation of the gas phase and the liquid phase substances of the natural gas is realized; the separated natural gas passes through the centrifugal separator 131, the natural gas after the first separation can be subjected to cyclone to generate centrifugal motion, the gas phase with lower density moves upwards in a centrifugal tube of the centrifugal separator 131 by utilizing the density difference between the liquid crystal and the gas phase in the natural gas, the liquid phase with relatively higher density moves downwards in the centrifugal tube, the centrifugal separation of the gas and the liquid is realized, and the separation scale is 10-20 mu m of liquid phase particles. The tiny liquid particles in the natural gas after the second gas-liquid separation pass through a coalescence wire net in the coalescer 1411, the tiny particle liquid is coalesced in the coalescence wire net to form larger liquid particles, and finally the liquid particles pass through a baffle plate separator 1412 in the separator component 141 to separate the larger (the particle size is more than 3 μm-5 μm) liquid particles coalesced by the coalescence wire net, and finally the high-efficiency separation of the wax-containing natural gas is realized.

Referring to fig. 2, in the present application, a three-stage separation chamber is provided in the separation container 1, so that a gas phase and liquid crystals in natural gas can be separated step by step, and a good separation effect is achieved. Because the natural gas is wax-containing natural gas, wherein the wax-containing natural gas can be high wax-containing natural gas, in consideration of the characteristic of high viscosity of the wax separated out in the separation process, the first stage separation chamber 12 and the second stage separation chamber 13 are thus provided before the separator assembly 141 of the third stage separation chamber 14, the gas phase and the liquid crystal in the natural gas are separated for the first time and the second time through the inertial separator 121 of the first stage separation chamber 12 and the centrifugal separator 131 of the second stage separation chamber 13, large particulate matters (such as wax) in the natural gas are separated from the natural gas, when the natural gas reaches the separator assembly 141 in the third stage separation chamber 14, the gas phase of the natural gas only contains a liquid phase of tiny particles, the risk of wax clogging the coalescing screen of the coalescer 1411, as occurs in vertical separators, is thereby avoided, and finally, efficient separation of waxy natural gas is achieved by the cryogenic separation device of this embodiment.

It should be noted that in the present embodiment, the centrifugal separator 131 may be a cyclone separator suitable for gas-liquid separation in the prior art or another centrifugal separator capable of being suitable for gas-liquid separation, that is, in the present embodiment, the centrifugal separator 131 includes, but is not limited to, a cyclone separator. Wherein, the cyclone separator can be a gas-liquid cyclone separator. Accordingly, coalescer 1411 may be a prior art coalescer suitable for gas-liquid separation, such as a gas-liquid coalescer. The coalescing screen is a structure in the coalescer 1411, such as a filter element of the coalescer 1411, capable of removing a small amount of liquid crystal (e.g., water droplets, oil droplets, etc.) in a gas phase, i.e., solid particles. In the present embodiment, the structures and types of the centrifugal separator 131, the coalescer 1411, and the baffle separator 1412 are not further limited.

Specifically, in the present embodiment, the baffle separator 1412 may be a corrugated plate separator or other baffle separation structure capable of performing gas-liquid separation, that is, in the present embodiment, the baffle separator 1412 includes, but is not limited to, a corrugated plate separator. Specifically, referring to fig. 6 and 7, the corrugated plate separator may be composed of a plurality of corrugated plates 14121 arranged in parallel, the corrugated plates 14121 being spaced apart (e.g., 10mm) and secured by a frame. The natural gas coalesced by the coalescer 1411 flows zigzag between the thin plates of the corrugated plate separator, the larger liquid particles coalesced by the coalescer 1411 in the gas phase are thrown onto the plate walls under the action of gravity, inertia force and gravity, under the action of adhesion force, water drops are adhered on the corrugated plate to form a water film, the water film is settled under the action of gravity, the liquid phase and the gas phase are further separated to separate the larger (more than 3-5 μm) liquid particles coalesced by the coalesced wire mesh, and finally the high-efficiency separation of the wax-containing natural gas is realized.

As a possible implementation manner, in order to make the first stage separation chamber 12, the second stage separation chamber 13, and the third stage separation chamber 14 in the separation container 1 communicate with each other, in this embodiment, through holes (not shown in the drawings) capable of allowing natural gas to flow through may be provided on the first stage separation chamber 12, the second stage separation chamber 13, and the third stage separation chamber 14, and the size and shape of the through holes need to be sufficient to allow natural gas to pass through and enter the separation operation of the next stage.

In the embodiment, referring to fig. 1, the inertial separator 121 and the centrifugal separator 131 may be fixed to the first stage separation chamber 12 and the second stage separation chamber 13 by fixing brackets, respectively, so that a certain gap exists between the inertial separator 121 and the centrifugal separator 131 and the bottom of the separation vessel 1, that is, the inertial separator 121 and the centrifugal separator 131 may be disposed as close as possible to the middle of the natural gas flowing direction by the fixing brackets, so that more natural gas can enter the inertial separator 121 and the centrifugal separator 131 to increase the gas-liquid separation effect of the natural gas.

It is understood that the greater the velocity of the natural gas colliding with the inertial separator 121, the better the first gas-liquid separation. Therefore, in order to obtain a better first gas-liquid separation effect, in the present embodiment, the natural gas may collide with the inertial separator 121 at a preset speed, wherein the separation effect is better when the preset speed is larger, for example, the preset speed is greater than 0m/s and less than or equal to 200 m/s. In practice, the preset rate of the natural gas entering the inertial separator 121 may be adjusted within the above range, and in this embodiment, the preset rate is not further limited.

By arranging the inertial separator 121, the centrifugal separator 131 and the separator assembly 141 in the separation vessel 1, wherein the separator assembly 141 comprises the coalescer 1411, the wax-containing natural gas is subjected to first gas-liquid separation by the inertial separator 121 to effectively perform first gas-liquid separation on gas-phase and liquid-phase substances of the natural gas, so as to separate heavy hydrocarbons (such as wax), alcohols and water in the natural gas; then, the natural gas is subjected to secondary gas-liquid separation through the centrifugal separator 131, and light hydrocarbon, a small amount of alcohol and water in the natural gas are separated; finally, the natural gas is subjected to third gas-liquid separation through the separator assembly 141, on the basis of realizing gas-liquid separation of the natural gas, the wax is separated during the first gas-liquid separation and the second gas-liquid separation, so that only a small amount of light hydrocarbon, a small amount of alcohol and water are contained in the natural gas entering the coalescer 1411, the risk that the coalescing screen in the coalescer 1411 is blocked by the wax is avoided, and the gas-liquid separation of the natural gas is realized without blocking the coalescing screen in the coalescer 1411. Therefore, the low-temperature separation device and the separation method provided by the embodiment realize the purpose of gas-liquid separation of the wax-containing natural gas, and solve the technical problem of poor separation performance of the existing vertical separator when the wax-containing natural gas is treated.

Specifically, referring to fig. 3 and 4, in the present embodiment, the inertial separator 121 includes a blocking plate 1211 and a plurality of blocking members 1212, and the plurality of blocking members 1212 are disposed on one side or both sides of the blocking plate 1211 along the natural gas flowing direction, so as to achieve a better blocking effect on the natural gas; in this embodiment, the set of baffles may be vertically disposed in the first-stage separation chamber 12 and parallel to the flowing direction of the natural gas, so as to collide with the blocking member 1212 and block the natural gas by the blocking member 1212 during the flowing process of the natural gas, thereby effectively separating the heavier liquid phase substances from the heavier gas phase substances. A plurality of baffling pieces 1212 are according to predetermined line spacing and row interval staggered arrangement on the group's baffle, have improved the circulation effect of natural gas to the probability that striking takes place for the increase and natural gas, the reinforcing is to the effect that the natural gas blockked, makes the natural gas must carry out liquid phase and gaseous phase separation through baffling piece 1212 through the collision, avoids producing and omits, has strengthened the separation effect.

It should be understood that, referring to fig. 3 and 4, the offset arrangement of the plurality of blocking members 1212 on the set of baffles according to the preset row and column pitches may be understood as a unit of column, illustrating the offset arrangement of the blocking members 1212. For example, the second row of barriers 1212 on the barrier 1211 is located between the first row of barriers 1212 and the third row of barriers 1212, and the second row of barriers 1212 is disposed slightly higher than the first row of barriers 1212 and the third row of barriers 1212, so as to fill the blank area between the first row of barriers 1212 and the third row of barriers 1212. Specifically, in practical applications, the preset row spacing and the preset column spacing may be adjusted according to actual needs, and in this embodiment, the preset row spacing and the preset column spacing are not further limited as long as the natural gas inevitably passes through the blocking member 1212 to perform liquid phase and gas phase separation through collision.

Further, referring to fig. 3 and 4, the blocking member 1212 is a bent structure, and the blocking member 1212 includes an air inlet end 12121, a guiding portion 12122, and a bent end 12123 opposite to the air inlet end 12121 and blocking natural gas; guide portion 12122 is coupled between intake end 12121 and bent end 12123 for directing the flow of natural gas between intake end 12121 and bent end 12123. In this embodiment, the opening end and the bent end 12123 of the blocking member 1212 are arranged in the natural gas flowing direction, so that the natural gas collides with the blocking member 1212 when flowing through the inertial separator 121 under the action of the inertial force, thereby separating the heavier liquid phase substances (such as wax) from the gas phase substances. Specifically, in the present embodiment, the blocking member 1212 includes, but is not limited to, a unitary structure.

Referring to fig. 3 and 4, in the present embodiment, the width of barrier 1212 is gradually decreased in the direction from air inlet end 12121 to bent end 12123, that is, the width of barrier 1212 is larger at air inlet end 12121 and smaller at bent end 12123, so that natural gas can more easily collide with barrier 1212 when flowing through inertial separator 121, so as to effectively separate the liquid phase material (such as wax) with heavy weight from the gas phase material. For example, the blocking member 1212 may be a V-shaped or other bent plate, i.e. in this embodiment, the blocking member 1212 includes, but is not limited to, a V-shaped bent plate.

In order to enhance the collision effect of the natural gas with the blocking member 1212, referring to fig. 3 and 4, in this embodiment, two sides of the air inlet 12121 are respectively provided with a bending portion 12124 bending toward the inside of the blocking member 1212, and the bending portion 12124 is used for blocking the natural gas rebounded to the air inlet 12121 after being blocked by the bending end 12123, so that the natural gas collides with the bending portion 12124 again, the liquid phase substances in the natural gas after the first gas-liquid separation are further separated, the liquid phase is attached to the blocking member 1212 and coalesces, and descends along the vertical flow direction, thereby effectively improving the first gas-liquid separation effect of the natural gas.

Referring to fig. 5, since a large amount of heavy hydrocarbons, alcohols and water in the natural gas are separated from the gas phase in the natural gas after the first gas-liquid separation, but there are still very few heavy hydrocarbons (such as wax) in the natural gas after the first gas-liquid separation, the very few wax in the natural gas after the first gas-liquid separation may block the cyclone elements 1311 (such as cyclone blades) in the centrifugal separator 131 with the increase of the processing time, so that the cyclone separation is disabled, thereby reducing the gas-liquid separation effect of the cryogenic separation device on the natural gas.

To this end, referring to fig. 2 and 5, in this embodiment, a shower 132 is provided in second stage separation chamber 13, shower 132 being used to wash out clogged wax from centrifugal separator 131 to avoid clogging of cyclone element 1311 wax in centrifugal separator 131, causing cyclone separation failure. Illustratively, in this embodiment, the sprayers 132 may be light hydrocarbon sprayers 132 or a spraying device in which the gas can clean the clogged wax from the centrifugal separator 131, i.e., in this embodiment, the sprayers 132 include, but are not limited to, light hydrocarbon sprayers 132. Wherein a shower 132 may be fixed to the top of the second stage separation chamber 13 by a fastener (not shown) and disposed opposite to the centrifugal separator 131, and when the centrifugal separator 131 is required to be cleaned, an opening (not shown) of the centrifugal separator 131 may be opened so that the shower 132 can clean the wax clogged on the centrifugal separator 131.

It should be noted that after the natural gas is processed by the centrifugal separator 131 in the second stage separation chamber 13, 10 to 20 μm liquid particles in the natural gas can be separated from the gas phase, and the 10 to 20 μm liquid particles may include light hydrocarbons, alcohols, and water in the natural gas.

It is well known that light hydrocarbons and heavy hydrocarbons are often distinguished by the number of carbon atoms, with the higher number of carbon atoms being referred to as heavy and the lower number of carbon atoms being referred to as light. Generally, less than 11 carbon atoms are referred to as light hydrocarbons, such as ethane, and more than 11 carbon atoms are referred to as heavy hydrocarbons, such as waxes.

Referring to fig. 2, 6 and 7, in the present embodiment, the baffle separator 1412 may be a corrugated plate separator provided at the gas outlet end of the coalescer 1411, and is used for separating the liquid phase formed by the coalescence of the coalescer 1411 from the gas phase in the natural gas, discharging the gas phase from the separation vessel 1, and separating the liquid particles of 3-5 μm or more from the natural gas by the corrugated plate separator.

Further, as shown in fig. 2, in this embodiment, an air inlet cavity 11 is provided in the separation container 1, the air inlet cavity 11 is located on one side of the first-stage separation cavity 12 departing from the second-stage separation cavity 13, and an air inlet 15 and a distributor 17 communicated with the air inlet 15 are provided in the air inlet cavity 11, so as to uniformly distribute the gas-liquid phase fluid in the input natural gas, which is beneficial to improving the gas-liquid separation effect in the later stage. Wherein the sparger 17 is disposed obliquely within the separation vessel 1 and opposite the inertial separator 121 so as to increase the effective length of the sparger 17 for optimal gas-liquid mixing to achieve an optimal homogeneous state. Illustratively, the distributor 17 is disposed at an acute angle, such as 45 degrees, within the inlet chamber 11. The distributor 17 in this embodiment may refer to the distributor 17 in the prior art, which is suitable for uniformly distributing gas and liquid. In practical applications, the connection angle between the distributor 17 and the gas inlet 15 may be set according to specific situations, so that the gas-liquid mixture reaches an optimal uniform state, and in this embodiment, the inclination angle of the distributor 17 is not further limited.

Further, referring to fig. 2, in the present embodiment, a liquid storage container 2 is further included, which is located at the bottom of the separation container 1 and is communicated with the separation container 1, and the liquid storage container 2 includes three independent liquid storage chambers; the three independent liquid storage chambers respectively comprise a first liquid storage chamber 21 communicated with the first-stage separation chamber 12, a third liquid storage chamber 23 communicated with the second-stage separation chamber 13, and a third liquid storage chamber 23 communicated with the third-stage separation chamber 14, so that liquid phases subjected to gas-liquid separation step by step are classified and recycled.

After the high wax-bearing natural gas enters the separators in the separation container 1, under the action of gravity at each stage of the separators, a large amount of heavy components and wax components are separated out, liquid phase substances after separation are carried out through the separators in the three separation cavities, the heavy components and the wax components flow downwards due to the action of gravity and are respectively gathered in the corresponding three liquid storage cavities, the three separation stages are respectively corresponding to the three liquid storage cavities, the separated liquid in each stage is stored, liquid drainage in each stage is enabled not to be influenced with each other, the influence on subsequent separation elements is avoided, the liquid drainage process is ensured to be carried out smoothly, continuous forward movement of a large particle liquid phase is avoided, normal high-efficiency separation of the subsequent separators can be guaranteed, and finally high-efficiency separation of gas and liquid is realized.

Specifically, in this embodiment, the natural gas subjected to the first gas-liquid separation by the inertial separator 121 continues to flow to the second-stage separation chamber 13 after passing through the inertial separator 121 of the first communication pipe 3, the separated liquid-phase substance flows into the first liquid storage chamber 21 after being coalesced, and a large amount of mixture of heavy hydrocarbon, alcohol, water, and the like is contained in the first liquid storage chamber 21. The natural gas after the second gas-liquid separation by the centrifugal separator 131 continuously flows to the third-stage separation chamber 14 after passing through the cyclone separator, the separated liquid-phase substance is coalesced and then flows into the second liquid storage chamber 22 through the second communicating pipe 4, and a mixture of light hydrocarbon and a small amount of alcohol and water is contained in the second liquid storage chamber 22. The natural gas which is subjected to the third gas-liquid separation by the coalescence wire mesh and the corrugated plate separator in the coalescer 1411 is discharged through the gas outlet 16 of the separation container 1, the separated liquid phase substance is coalesced and then flows into the third liquid storage chamber 23 through the third communicating pipe 5, and a small amount of light hydrocarbon, a small amount of alcohol and water mixture are contained in the third liquid storage chamber.

In this embodiment, referring to fig. 2, the gas inlet 15 and the gas outlet 16 of the separation vessel 1 are respectively disposed at two ends of the separator, and natural gas is fed into the separator through the gas inlet 15 at a certain pressure, so that the natural gas can conveniently circulate in the separation vessel 1. On the basis, the gas outlet 16 is used for connecting a subsequent pipeline, so that the qualified product gas is sent to the subsequent pipeline.

Preferably, referring to fig. 2, in this embodiment, the second liquid storage chamber 22 is communicated with the liquid outlet of the centrifugal separator 131 through the second communicating pipe 4, so that the liquid-phase substance effectively flows into the second liquid storage chamber 22 through the second communicating pipe 4, the liquid-phase substance is prevented from remaining in the second-stage separation chamber 13, and the collecting effect of the liquid-phase substance after the second gas-liquid separation is effectively achieved. The gas phase separated by centrifugal separator 131 is discharged from centrifugal separator 131 through another outlet and enters coalescer 1411 of third stage separation chamber 14.

Further, referring to fig. 2, in the present embodiment, the third liquid storage chamber 23 is communicated with the third stage separation chamber 14 through a third communicating pipe 5, and an inner inserting pipe 6 is arranged in the third communicating pipe 5, one end of the inner inserting pipe 6 is communicated with a baffle separator 1412 (such as a corrugated plate separator), and the other end is inserted into the third liquid storage chamber 23. Through the separation of the coalescence wire net in the coalescer 1411, after liquid phase substances in the natural gas flow into the third liquid storage chamber 23 through the third communicating pipe 5, the liquid phase substances after the gas-liquid separation of the natural gas in the corrugated plate separator directly flow into the third liquid storage chamber 23 through the inner inserting pipe 6, and the collection effect of the liquid phase substances is effectively realized.

Specifically, referring to fig. 2, in the present embodiment, a first liquid outlet 211 is disposed on a cavity wall of the first liquid storage chamber 21; a second liquid outlet 221 is arranged on the wall of the second liquid storage chamber 22; a third liquid outlet 231 is provided on the wall of the third reservoir chamber 23, so that the liquid phase in each reservoir chamber is discharged through the first liquid outlet 211, the second liquid outlet 221 and the third liquid outlet 231 for reuse. Specifically, first liquid outlet 211, second liquid outlet 221 and third liquid outlet 231 all are equipped with governing valve 7, have realized the pressure regulating of liquid in each stock solution cavity through three governing valve 7 and have carried.

In order to facilitate the routine maintenance of the separation container 1, referring to fig. 2, in the present embodiment, a maintenance valve is disposed at an end of the third-stage separation chamber 14, which is beneficial to the routine maintenance of the separation container 1 and ensures the normal operation of the cryogenic separation device.

Specifically, low temperature separator can adopt upper and lower double-deck horizontal structure in this embodiment, and receiver 2 is located the lower floor of receiver 1 promptly to the liquid phase after the separation can get into corresponding stock solution cavity under the effect of gravity in order to realize the collection effect to the liquid phase material.

According to the low-temperature separation device provided by the invention, through the arrangement of the inertial separator, the centrifugal separator and the separator component in the separation container, firstly, the gas phase and the liquid phase substances of the natural gas after low-temperature treatment are sequentially subjected to primary gas-liquid separation and secondary gas-liquid separation through the inertial separator and the centrifugal separator, the gas phase of heavy hydrocarbon (such as wax), light hydrocarbon, alcohol and water in the natural gas and the gas phase of the natural gas are separated, and then the gas phase in the natural gas enters the coalescer in the separator component, so that the gas-liquid separation of the natural gas is realized, and meanwhile, the blockage of a coalescing wire net in the coalescer is avoided.

Example two

Fig. 8 is a schematic flow chart of a separation method according to a second embodiment of the present invention.

Further, on the basis of the cryogenic separation device of the above embodiment, referring to fig. 8, in this embodiment, an embodiment of the present invention provides a separation method suitable for a waxy natural gas, including the following steps:

s100: get into the inertial separation ware 121 in the separator 1 with the natural gas, carry out first order gas-liquid separation to the natural gas through inertial separation ware 121, granule and liquid in the natural gas take place the striking with inertial separation ware 121 with preset speed to constantly gathering on inertial separation ware 121 is attached to, under the action of gravity, the mixed liquid of heavy hydrocarbon, mellow wine, water gets into first stock solution cavity 21 through first connecting pipe 3.

S200: the natural gas after the first stage of gas-liquid separation enters a centrifugal separator 131 in the separation container 1, and the natural gas is subjected to second stage gas-liquid separation through the centrifugal separator 131; under the action of the centrifugal force of the centrifugal separator 131, the gas-liquid mixture is separated from the gas phase by 10-20 μm liquid particles in the natural gas, and the mixed liquid particles of light hydrocarbon, alcohol and water are accumulated and then enter the second liquid storage cavity through the second communicating pipe 4 under the action of gravity.

Further, when centrifugal separator 131 is clogged with condensed wax, shower 132 is activated to wash out the clogged wax from centrifugal separator 131, thereby ensuring proper operation of centrifugal separator 131.

S300: the natural gas after the second-stage gas-liquid separation enters a separator assembly 141 in the separation container 1, a liquid phase in the natural gas is coalesced through a coalescer 1411 in the separator assembly 141, the natural gas is subjected to third-stage gas-liquid separation through a corrugated plate separator in the separator assembly 141 to obtain a gas phase in the natural gas, and separated liquid particles with the particle size of more than 3-5 mu m enter a third liquid storage cavity through an inner insertion pipe 6 under the action of gravity.

S400: the gas phase is discharged from the separation vessel 1, and the natural gas (i.e., the gas phase) subjected to gas-liquid separation by the first-stage separation chamber 12, the second-stage separation chamber 13, and the third-stage separation chamber 14 is discharged through the gas outlet.

S500: and respectively collecting liquid phases obtained after the first-stage gas-liquid separation, the second-stage gas-liquid separation and the third-stage gas-liquid separation. Specifically, the liquid storage container 2 is divided into three independent liquid storage cavities for separating and isolating liquids with different densities in the low-temperature separator, the first liquid storage cavity 21 is filled with a large amount of mixture of heavy hydrocarbon, alcohol, water and the like, and the second liquid storage cavity 22 is filled with light hydrocarbon and a small amount of mixture of alcohol and water; the third reservoir chamber 23 is a small amount of light hydrocarbon and a small amount of alcohol-water mixture.

After the natural gas with high wax content enters the first-stage separation chamber 12 of the separation container 1, a large amount of heavy components and wax components are separated out under the action of the inertial separator 121 and gravity, and enter the first liquid storage chamber 21, so that the influence on a subsequent separator is avoided. Therefore, normal and efficient separation of the follow-up separator can be guaranteed, and efficient separation of gas and liquid is finally realized.

Specifically, the natural gas with high wax content (i.e., the low-temperature gas-liquid mixture of the natural gas) enters the separation container 1 from the gas inlet, the natural gas is rectified by the distributor 17, and the gas and the liquid are uniformly distributed and then enter the inertial separator 121. The natural gas collides with the inertial separator 121 at a certain speed to realize first gas-liquid separation of gas and liquid, large particles and liquid (mainly wax and heavy components) in the natural gas are attached to the inertial separator 121 and continuously accumulated, the liquid enters the first liquid storage chamber 21 through the first communication pipe 3 under the action of gravity, and the separated gas continuously moves to the second separation chamber through a channel (namely, a gap between the blocking pieces 1212) of the inertial separator 121.

The natural gas subjected to the first gas-liquid separation enters the centrifugal separator 131, 10-20 μm liquid particles and a gas phase of the gas-liquid mixture are separated under the action of centrifugal force, and the liquid particles are accumulated and then enter the second liquid storage chamber 22 through the centrifugal separator 131 and the second communicating pipe 4 under the action of gravity; the separated natural gas contains a trace amount of liquid droplets and enters the third stage separation chamber 14.

The natural gas after the second gas-liquid separation is subjected to a third gas-liquid separation through a coalescence wire mesh in the coalescer 1411, wherein the ultrafine particle liquid is coalesced in the coalescence wire mesh, liquid particles with the particle size of more than 3-5 mu m are separated through the corrugated plate separator, and the liquid particles with the particle size of more than 3-5 mu m enter the third liquid storage chamber 23 through the inner insertion pipe 6 under the action of gravity.

The separation method provided by the invention firstly carries out first gas-liquid separation and second gas-liquid separation on gas-phase and liquid-phase substances of the natural gas in sequence through the inertial separator and the centrifugal separator, separates the gas phase of heavy hydrocarbon (such as wax), light hydrocarbon, alcohol and water in the natural gas and the natural gas, and then enables the gas phase in the natural gas to enter the coalescer in the separator component, thereby realizing the gas-liquid separation of the natural gas and avoiding the blockage of a coalescing screen in the coalescer.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be considered as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "comprises" and "comprising," and any variations thereof, as used herein, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integral to one another; either directly or indirectly through intervening media, such as through internal communication or through an interaction between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. A low-temperature separation device is suitable for gas-liquid separation of wax-containing natural gas and is characterized by comprising a separation container, wherein a first-stage separation chamber, a second-stage separation chamber and a third-stage separation chamber which are communicated with each other are sequentially arranged in the separation container along the circulation direction of the natural gas;

the separator assembly comprises a coalescer and a baffle separator which are sequentially arranged in the flowing direction of natural gas, and the natural gas is used for sequentially flowing through the inertial separator, the centrifugal separator, the coalescer and the baffle separator so as to separate gas phase and liquid phase in the natural gas.

2. The cryogenic separation device of claim 1, wherein the inertial separator comprises a baffle plate and a plurality of baffle members disposed on one or both sides of the baffle plate in the direction of circulation of the natural gas;

the barriers are arranged on the group of baffles in a staggered mode according to preset line spacing and column spacing and used for separating liquid phase from gas phase in the natural gas.

3. The cryogenic separation device of claim 2, wherein the baffle is a bent structure comprising an inlet end, a guide, and a bent end disposed opposite the inlet end and blocking the natural gas; the guide portion is connected between the air inlet end and the bent end and used for guiding the natural gas to circulate between the air inlet end and the bent end.

4. The cryogenic separation device of claim 3, wherein the width of the barrier decreases in a direction from the inlet end to the bent end.

5. The cryogenic separation device of claim 4, wherein two sides of the inlet end are respectively provided with a bending portion bending towards the inside of the blocking member, and the bending portion is used for blocking the natural gas rebounding to the inlet end after being blocked by the bending portion.

6. A cryogenic separation device according to claim 1, wherein a shower is provided in the second stage separation chamber for flushing clogged wax from the centrifugal separator.

7. The cryogenic separation device of any one of claims 1 to 6 wherein the baffle separator is a corrugated plate separator disposed at the gas outlet end of the coalescer for separating the liquid phase formed by coalescence of the coalescer from the gas phase in the natural gas for discharge from the separation vessel.

8. The cryogenic separation device of any one of claims 1 to 6, wherein an air inlet chamber is arranged in the separation vessel, the air inlet chamber is located on a side of the first stage separation chamber facing away from the second stage separation chamber, an air inlet and a distributor communicated with the air inlet are arranged in the air inlet chamber, and the distributor is obliquely arranged in the separation vessel and is opposite to the inertial separator.

9. A cryogenic separation device according to any one of claims 1 to 6, further comprising a reservoir located at the bottom of the separation vessel and in communication with the separation vessel, the reservoir comprising three separate reservoir chambers;

the three independent liquid storage chambers comprise a first liquid storage chamber communicated with the first-stage separation chamber, a third liquid storage chamber communicated with the second-stage separation chamber, and a third liquid storage chamber communicated with the third-stage separation chamber.

10. A separation process suitable for waxy natural gas, comprising the steps of:

enabling the natural gas to enter an inertial separator in a separation container, and carrying out first-stage gas-liquid separation on the natural gas through the inertial separator;

the natural gas subjected to the first stage of gas-liquid separation enters a centrifugal separator in the separation container, and the natural gas is subjected to second stage gas-liquid separation through the centrifugal separator;

the natural gas subjected to the second-stage gas-liquid separation enters a separator component in the separation container, a liquid phase in the natural gas is coalesced through a coalescer in the separator component, and then the natural gas is subjected to third-stage gas-liquid separation to obtain a gas phase in the natural gas;

discharging the gas phase from the separation vessel;

and respectively collecting liquid phases obtained after the first-stage gas-liquid separation, the second-stage gas-liquid separation and the third-stage gas-liquid separation.

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