Gas / condensate separator with cleaning nozzle, and corresponding cleaning procedure

Abstract

Gas / condensate separator with cleaning nozzle, and corresponding cleaning method. Gas / condensate separator comprising a tank (1) equipped with a filter (2) separating an upper portion (1b) of the tank from a lower portion (1a) of the tank, an inlet (E) opening in the lower part for introducing the gas / condensate mixture into the tank, a first outlet (S1) in the upper part for extracting the gas filtered by the filter from the tank, a second outlet (S2) located in the lower part for extracting the condensate, characterized in that the separator further comprises at least one nozzle (B1) for dispersing a cleaning liquid arranged in the upper part of the tank, dispersing the cleaning liquid by sweeping over at least the upper face (2S) of the filter oriented towards the upper portion. Figure for the abstract: Fig. 1

Description

Title of the invention: Gas / condensate separator with cleaning nozzle, and corresponding cleaning method. Technical field

[0001] The present invention relates to the treatment of fluids, and more specifically to gas / condensate separators. Previous technique

[0002] Separators are used in gas treatment systems, for example in exploration, production, and refining facilities in the petrochemical industry. Separators can also be called degassers.

[0003] A typical application is the treatment of natural gas including condensates (typically oils). In these applications, clogging of the separator can be observed, and more specifically clogging of the filter used as a demister.

[0004] Prior art separators generally comprise a substantially vertical tank, an inlet to receive the gas / condensate mixture, an outlet located at the top of the tank to extract the filtered gas, and a filter arranged between the inlet and the outlet (the filter may be called a devesiculator, or coalescing mattress).

[0005] From the prior art, we know of document FR 3100992 which describes the fouling phenomenon of gas / liquid separators, but for a separator without a filter. This document proposes using a diluent liquid (hydrocarbon) in a cyclone to limit fouling.

[0006] Separators for gas / sludge mixtures are also known, for example, those described in document WO 2019 / 060098. This document proposes a separator with a filter and addresses the problem of filter fouling. However, in the application covered by this document, this problem is solved by vibrations that clean the filter.

[0007] For certain applications, a more thorough cleaning of the separator, or at least its filter, must nevertheless be carried out in case of clogging or to prevent clogging. For this purpose, cleaning is performed by removing the separator flanges, the vents, and the pressure gauge used, so that an operator can then carry out the cleaning.

[0008] These operations are lengthy, and can last up to two days due to the necessary disassembly / reassembly.

[0009] Furthermore, condensates are hazardous to operators (for example, classified as carcinogenic, mutagenic, and toxic to reproduction (CMR)), and operators must therefore be equipped with appropriate personal protective equipment and costly. This danger also results in significant cleaning costs.

[0010] It is therefore necessary to find a solution which limits at least in part: the risks of exposure to hazardous products for operators, the loss of time, the costs, and finally the cases of pollution caused by the clogging of the filters.

[0011] The invention aims to resolve at least some of the aforementioned drawbacks. Description of the invention

[0012] To this end, the invention proposes a gas / condensate separator comprising a tank equipped with a filter separating an upper portion of the tank from a lower portion of the tank, an inlet opening into the lower part to introduce the gas / condensate mixture into the tank, a first outlet in the upper part to extract the gas filtered by the filter from the tank, a second outlet located in the lower part to extract the condensate.

[0013] According to a general feature, the separator includes at least one cleaning liquid dispersion nozzle arranged in the upper part of the tank, dispersing the cleaning liquid by sweeping over at least the upper face of the filter oriented towards the side of the upper portion.

[0014] Thus, a solution to the problems posed above was found in the installation of a cleaning fluid dispersing nozzle that sweeps across the entire upper surface of the filter. Here, the filter occupies an entire section of the tank to demarcate the lower portion from the upper portion.

[0015] This solution avoids having to dismantle the tank for cleaning, and avoids any dangerous exposure for operators.

[0016] In addition, sweeping with a suitable cleaning fluid to mechanically move the condensates has been observed to be well suited to prevent the fouling of the filters.

[0017] According to a particular embodiment, the separator further comprises a second cleaning liquid dispersion nozzle arranged in the lower portion of the tank and dispersing the cleaning liquid by sweeping over at least the bottom of the tank.

[0018] This particular embodiment also makes it possible to prevent fouling at the level of the second outlet of the separator, which is generally located at the bottom of the tank.

[0019] According to a particular embodiment, the second dispersion nozzle is arranged at a lower level than the inlet to introduce the gas / condensate mixture.

[0020] This particular embodiment is well suited for separators in which a deflector is placed opposite the inlet to block the condensate and make it fall to the bottom of the tank.

[0021] According to a particular embodiment, the separator further comprises an outlet pipe extending from the first outlet and equipped with a flame arrester, and a third dispersion nozzle arranged above the flame arrester dispersing the cleaning liquid by sweeping over the flame arrester (and in particular over its upper face).

[0022] As an indication, the third nozzle will be placed in line with the outlet pipe if it is vertical, and in line with the separator (of the tank).

[0023] According to a particular embodiment, the dispersion nozzle(s) are rotary nozzles, driven in rotation by the cleaning liquid.

[0024] This particular embodiment is advantageous in that it allows the use of nozzles that rotate without an electric motor, which would be problematic in a context where the gas, for example, is explosive.

[0025] According to a particular embodiment, the dispersion nozzle(s) are configured to perform an orbital sweep to disperse the cleaning liquid.

[0026] By orbital, we mean that the nozzle makes a jet travel a rotation around an axis (typically orthogonal to the wall of the tank at the level where the nozzle is arranged), and also an oscillatory movement in the direction of this axis.

[0027] According to a particular embodiment, the nozzle(s) are nozzles according to the ATEX standard.

[0028] The ATEX standard (ATmosphères Explosives), defined in particular in European directives 2014 / 34 / EU and 1999 / 92 / EC, implies technical characteristics on the nozzle.

[0029] By way of example, these nozzles may be made of stainless steel, be able to rotate without an electrical component (the movement of the fluid will be used for example), etc.

[0030] Nozzle manufacturers generally identify the nozzles they market in accordance with this standard.

[0031] According to a particular embodiment, the cleaning liquid is, in the nozzles (i.e. before dispersion), at a pressure between 3 bar and 5 bar measured relative to the pressure inside the tank or at a pressure between 3 bar and 10 bar measured relative to the pressure inside the tank.

[0032] It has been observed that with high pressure, there is a mechanical cleaning action by the cleaning liquid, which dislodges the condensates clogging the filter (or other elements, if more nozzles are used).

[0033] The invention also proposes a gas treatment installation comprising the separator as defined above (in all its embodiments), a gas / condensate mixture supply connected to said inlet, an outlet line connected to the first outlet (or connected to the outlet line of the separator if it has one), and a supply of cleaning fluid (for example maintained at a pressure between 3 bar and 10 bar measured relative to the pressure inside the tank).

[0034] The invention also proposes a method for cleaning (at least partially) a gas / condensate separator comprising a tank equipped with a filter separating an upper portion of the tank from a lower portion of the tank, an inlet opening into the lower part to introduce the gas / condensate mixture into the tank, a first outlet in the upper part to extract the gas filtered by the filter from the tank, a second outlet located in the lower part to extract the condensate, in which a cleaning liquid is dispersed by means of a nozzle arranged in the upper part of the tank, the cleaning liquid being dispersed by sweeping over at least the upper face of the filter oriented towards the side of the upper portion.

[0035] This method can be implemented using a separator as defined above in all its embodiments, in particular, this method can include the use of several dispersion nozzles.

[0036] According to a particular embodiment, the cleaning is carried out during a cleaning phase separate from a gas / condensate separation phase.

[0037] According to a particular embodiment, the cleaning fluid comprises water and / or a degreaser.

[0038] Thus, a mechanical cleaning of the separator can be implemented.

[0039] According to a particular embodiment, the cleaning liquid is brought to the dispersion nozzle at a pressure between 3 bar and 5 bar measured relative to the pressure inside the tank or at a pressure between 3 bar and 10 bar measured relative to the pressure inside the tank.

[0040] Brief description of the drawings

[0041] Other features and advantages of the present invention will become apparent from the description below, with reference to the accompanying drawings, which illustrate an example of an embodiment without being limiting in any way. In the figures:

[0042] [Fig-1] The [Fig.1] is a cross-sectional view of a separator according to an example.

[0043] [Fig.2] Fig.2 is a three-dimensional representation of a nozzle according to a example. Description of the implementation methods

[0044] We will now describe a separator that can be used in a gas processing installation.

[0045] This installation can be used in an exploration, production, or refining context for the petrochemical industry.

[0046] In [Fig. 1], a separator is shown in a gas processing plant which is partially shown.

[0047] This separator comprises a tank 1, intended to be used as shown, i.e. vertically (to have a difference in elevation between the inlet and the outlet). The tank has a substantially cylindrical shape with a circular cross-section.

[0048] To separate the gas from the condensate received by this separator, a filter 2 is arranged across a section of the separator, such that a lower portion 1a and an upper portion 1b of the tank are defined by the filter arrangement. It should be noted that the filter can also be referred to as a devesiculator or coalescing mat. The filter used here will be chosen for an application of filtering oil-type condensate contained in a methane / natural gas.

[0049] The gas treatment plant here includes a gas / condensate supply line 3, here a pipe. This supply line opens into the lower portion of the tank to define the tank inlet E. A stop 4, here a surface orthogonal to the axis of the supply line 3, is arranged in the tank so that at least a portion of the condensate encounters it and then falls to the bottom 5 of the tank by gravity. The stop is held in place by a band that extends the supply line into the tank.

[0050] To extract the gas that rises in the separator and has been filtered by filter 2, the tank has a first outlet SI, here an opening in the tank wall located at the top of the tank. A vertical outlet pipe 6 (along the axis of the tank) is connected to outlet SI. A flame arrester 7 is mounted in outlet pipe 6. Pipe 6 opens into another outlet pipe 8 of the gas treatment plant.

[0051] To extract the condensate, which will at least partially reach the bottom 5 of the tank, a second outlet S2 is arranged as an opening in the bottom wall of the tank, at the lowest point of the tank. This second outlet S2 is connected to a line 9 of the gas treatment plant to extract the condensate.

[0052] To solve the problem of the fouling of filter 2, it is proposed to use a nozzle Bl, arranged in the upper part of the tank (on its wall), to disperse a cleaning liquid by sweeping over the upper face 2S of filter 2.

[0053] The cleaning fluid can be a solvent such as water, but other solvents can also be used, particularly alcohol-based solvents commonly used as degreasers. A mixture of solvents is also possible. The cleaning fluid supply is included in the gas treatment system but is not shown here for simplicity. Preferably, and to achieve good cleaning, this supply maintains the cleaning fluid at a pressure between 3 bar and 50 bar, measured relative to the pressure inside the tank (a typical flow rate might be 50 L / min). more preferably at a pressure between 3 and 10 bars.

[0054] To achieve a sweep of the surface, or even the entire surface 2S, a rotating nozzle, driven in rotation by the cleaning fluid (more precisely by its pressure), can be used. In fact, the nozzle can be ATEX compliant. Furthermore, the sweeping can be orbital.

[0055] A nozzle usable as a B1 nozzle is shown in [Fig.2].

[0056] As an example, a nozzle from the American company BETE may be used, for example the orbital nozzle marketed under the reference HWS-40.

[0057] An orbital nozzle causes a jet to rotate around an axis (typically orthogonal to the tank wall where the nozzle is located, but possibly forming a non-right angle with the wall), and also to oscillate along this axis. Different combinations of rotational and oscillatory motions can be used. Furthermore, the nozzle may have several outlet orifices.

[0058] Preferably, the orbital nozzle allows the surface of at least one hemisphere centered on the nozzle to be scanned. In fact, the scanning motion of the nozzles of the invention can be a hemispherical scan.

[0059] To obtain a more complete cleaning of the separator tank, additional nozzles can be arranged. In particular, a nozzle B2 can be placed in the lower portion of the tank, below the level of the inlet E, to implement a sweeping of the bottom 5 of the tank (which will not be hindered by the presence of the stop 4 since it is below its level).

[0060] Another nozzle B3 can be arranged above the flame arrester 7, in line with the outlet pipe 6, at the T-shaped junction which connects the outlet pipe 6 with the pipe 8.

[0061] With nozzles B1, B2, and B3, complete cleaning of the separator and flame arrester components can be achieved. Indeed, all components susceptible to being fouled by condensate are swept away by the jets of the nozzles.

[0062] More nozzles can be used.

[0063] It should be noted that the cleaning can be carried out during a phase separate from an operating phase of the separator. In other words, no gas / condensate mixture is introduced when the cleaning liquid is introduced.

[0064] The embodiments and implementation methods described above make it possible to avoid having to dismantle parts of the separator to clean the separator. Cleaning is thus much less expensive, quicker, and less dangerous for operators.

Claims

Demands

1. Gas / condensate separator comprising a tank (1) equipped with a filter (2) separating an upper portion (1b) of the tank from a lower portion (la) of the tank, an inlet (E) opening into the lower part for introducing the gas / condensate mixture into the tank, a first outlet (SI) in the upper part for extracting the gas filtered by the filter from the tank, a second outlet (S2) located in the lower part for extracting the condensate, characterized in that the separator further comprises at least one nozzle (Bl) for dispersing a cleaning liquid arranged in the upper part of the tank dispersing by sweeping the cleaning liquid over at least the upper face (2S) of the filter oriented towards the side of the upper portion, and in which the dispersing nozzle(s) are rotary nozzles, driven in rotation by the cleaning liquid.

2. Separator according to claim 1, further comprising a second cleaning liquid dispersion nozzle (B2) arranged in the lower portion of the tank and dispersing the cleaning liquid by sweeping over at least the bottom (5) of the tank.

3. Separator according to claim 2, wherein the second dispersion nozzle is arranged at a lower level than the inlet to introduce the gas / condensate mixture.

4. Separator according to claim 1 or 2, further comprising an outlet conduit (6) extending from the first outlet and provided with a flame arrester (7), and a third dispersion nozzle (B3) arranged above the flame arrester dispersing the cleaning liquid by sweeping over the flame arrester.

5. Separator according to claim 1, wherein the dispersion nozzle(s) are configured to perform an orbital sweep to disperse the cleaning liquid.

6. Separator according to any one of claims 1 to 5, wherein the nozzle(s) are nozzles according to the ATEX standard.

7. Separator according to any one of claims 1 to 6, wherein the cleaning liquid is, in the nozzles, at a pressure between 3 bar and 5 bar measured relative to the pressure inside the tank or at a pressure between 3 bar and 10 bar measured relative to the pressure inside the tank.

8. Gas treatment plant comprising the separator according to any one of claims 1 to 7, a gas / condensate mixture supply connected to said inlet, an outlet line connected to the first outlet or connected to the outlet line of the separator, and a cleaning fluid supply.

9. A method for cleaning a gas / condensate separator comprising a tank (1) equipped with a filter (2) separating an upper portion (1b) of the tank from a lower portion (la) of the tank, an inlet (E) opening into the lower part for introducing the gas / condensate mixture into the tank, a first outlet (S1) in the upper part for extracting the gas filtered by the filter from the tank, a second outlet (S2) located in the lower part for extracting the condensate, wherein a cleaning liquid is dispersed by means of a nozzle (B1) arranged in the upper part of the tank, the cleaning liquid being dispersed by sweeping over at least the upper face (2S) of the filter oriented towards the side of the upper portion, and wherein the dispersion nozzle(s) are rotary nozzles, driven in rotation by the cleaning liquid.

10. A method according to claim 9, wherein the cleaning is carried out during a cleaning phase separate from a gas / condensate separation phase.

11. A method according to claim 9 or 10, wherein the cleaning fluid comprises water and / or a degreaser.

12. A method according to any one of claims 9 to 11, wherein the cleaning liquid is brought to the dispersion nozzle at a pressure between 3 bar and 5 bar measured relative to the pressure inside the tank or at a pressure between 3 bar and 10 bar measured relative to the pressure inside the tank.

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