TECHNICAL FIELD
The present disclosure relates to sulphur recovery units. More specifically, the present disclosure relates to a sulphur seal device for sealing and degassing of liquid sulphur in a sulphur recovery unit.
BACKGROUND
Generally sulphur recovery units employ modified CLAUS process for the conversion of hydrogen sulphide gas to element sulphur. The elemental sulphur, which is formed in the process is condensed and removed from the system. Conventionally, a condenser is installed at each stage for converting the sulphur in vapour phase to liquid sulphur. The liquid sulphur thus formed is transported to a liquid sulphur pit by means of gravity drains. A plurality of sulphur seals are used in order to prevent the process gas containing hydrogen sulphide and sulphur dioxide from escaping through these gravity drains to the low pressure pit and subsequently into the atmosphere. Conventionally, an underground seal is employed which seals the gas by providing a liquid barrier in its path.
However, conventional seals have a pipe of about 20 feet length placed underground, thus making servicing and repairability of the seal cumbersome. Further, in the conventional system there is accumulation of debris at the bottom of the seal. As the seal is placed underground, cleaning of such debris from the seal also becomes difficult. Further, the maintenance of the system requires shutting down of the plant and pulling out the seal system from the ground by means of heavy machinery such as cranes, heavy duty lifters etc. All these factors make the maintenance of conventional seals very cumbersome and costly.
Further, the liquid sulphur obtained from the seal is required to be degassed for removing any residual hydrogen sulphide in the liquid sulphur. Conventionally, a

separate degassing equipment is required for degassing of liquid sulphur that leads to increase in overall costs and efforts in sulphur recovery.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 illustrates a schematic diagram of a device for above ground liquid sulphur seal with degassing, in accordance with an embodiment.
DESCRIPTION OF THE PRESENT DISCLOSURE
FIG. 1 illustrates a device for above ground liquid sulphur seal with degassing, hereafter referred to as the sealing device 10, in accordance with an embodiment. As shown in FIG. 1, the sealing device may include a housing 12 having a longitudinal axis 14. The housing may be of substantially cylindrical shape extending vertically along the longitudinal axis 14. The housing 12 may include a separator 16 defining a first chamber 18 and a second chamber 20 within the housing 12. The separator 16 may substantially be a plate dividing the inner portion of the housing 12 in two chambers, namely the first chamber 18 and the second chamber 20. In the embodiment as illustrated, the first chamber 18 is positioned towards a bottom 22 of the sealing device 10 and the second chamber 20 is positioned above the first chamber 18 towards a top 24 of the sealing device 10. Further, the first chamber 18 may have an inlet 26 for supply of liquid sulphur. The inlet 26 may be provided on a side wall of a portion of the housing 12 defining the first chamber 18. The first chamber 18 may also have debris removal openings 28 for cleaning the first chamber 18. The debris removal openings 28 may be provided on the side wall of the housing proximate to the bottom 22 of the sealing device. The debris removal openings 28 may be kept closed for operation of the sealing device 10 and opened when the sealing device 10 is required to be cleaned.
The second chamber may have an upper end 32 and a lower end 33. A top cover 30 may cap the upper end 32 of the second chamber 20. The second chamber 20 is provided with an outlet 34 for discharging liquid sulphur from the sealing device 10. The second chamber 20 may also be provided with a vent 36 for

discharging a gas from the second chamber 20. The vent 36 may be positioned towards the top 24 of the sealing device 10.
The sealing device 10 may further include a first tube 38 connected to the separator 16 and extending in the second chamber 20 along the longitudinal axis 14 such that the first tube 38 provides a first passage 40 for the liquid sulphur received in the first chamber 18 to flow towards the second chamber 20. The first tube 38 may have a first end 42 connected to the separator 16 and an open second end 44 positioned in the second chamber 20 towards but slightly below the top 24 of the sealing device 10.
The sealing device 10 further includes a second tube 46 having a diameter greater than the first tube 38 but smaller than that of the housing 12. The second tube 46 is positioned concentric with the first tube along the longitudinal axis 14 and arranged such that the second tube 46 receives the second end 44 of the first tube 38 and a portion of the first tube 38 within the second tube 46 as shown in FIG. 1. As illustrated, the second tube 46 is designed and arranged in the second chamber 20 such that a bottom end 50 of the second tube 46 lies at a distance from the separator 16 and a top end 48 of the second tube 46 lies above the second end 44 of the first tube 38 within the housing 12. The arrangement of the first tube 38 and the second tube 46 may provide a second passage 54 defined by an inner wall 56 of the second tube 46 and an outer wall 58 of the first tube 38. This arrangement ensures that the liquid Sulphur coming out from the second end 44 of the first tube 38 first flows towards the bottom of the second chamber 20 and then moves out of the sealing device 10 from the outlet 34, thus ensuring proper flow of the liquid Sulphur in the second chamber 20. It is to be noted that the outlet 34 is positioned such that the outlet 34 lies vertically below the top end 48 of the second tube 46 but above the bottom end 50 of the second tube 46. Also, the outlet is preferably positioned vertically closer to (and below) the top end 48 of the second tube 46 in order allow a sufficient level of liquid Sulphur in the second chamber 20 for operations as described later herein.

Further, the second end 44 of the first tube 38 may be configured for placing a stopper 60 on the second end 44 for closing the second end 44. The stopper 60 may be of a predetermined weight as needed. In an embodiment, the weight may be altered or varied as needed. The weight of the stopper 60 may be chosen such that passage of liquid Sulphur through the second end 44 is prevented until a certain pressure is built up in the first chamber 18 that is enough for overcoming the weight of the stopper 60 and thus lifting of the stopper 60 to open the second end 44 of the tube and allowing passage of liquid sulphur towards the second passage 54. In an embodiment, the weight of the stopper 60 may vary based on the size and capacity of the Sulphur recovery unit. As illustrated in FIG. 1, the stopper 60 is coupled to a guiding vane 52 through a tie-rod 64 to guide movement of the stopper 60. The guiding vane has a guide positioned in the first tube 38 and the guide is coupled to the stopper using any means such as a rod or a rope. The stopper 60 may be designed as required.
As illustrated in FIG. 1, the sealing device 10 may further include a sparger 62 placed in the second chamber 20. The sparger 62 is used for degassing the liquid sulphur in the second chamber 20. In the embodiment as illustrated, the sparger 62 is positioned below the bottom end 50 of the second tube 46 and above the separator 16. The sparger 62 may be configured for introducing gas bubbles in the liquid sulphur present in the second chamber 20. Any gas suitable for the process may be used, for example air. In the embodiment as illustrated, the sparger 62 is shown as a circular tube having holes (not shown) on its walls for release of gas bubbles. It may be understood that the shape and the size of the sparger and the number or shape of holes may be designed as required. Further, it may also be understood that the positioning of the sparger 62 in the second chamber 20 may also be altered without affecting the overall operation of the sealing device 10 as required. For example, in an embodiment, the sparger 62 may be positioned such that it lies above the bottom end 50 of the second tube 46 and outside the periphery of the second tube 46. The sparger 62 may be coupled to a source of pressurized gas 68 for supplying pressurized gas to the sparger 62. Furthermore, it may be understood that in an alternate embodiment, the shape and

the structure of the sealing device may differ while achieving a similar function and similar result. The different components of the sealing device as described above may be assembled detachably so that maintenance of the device can be performed with convenience. Suitable arrangement may be used to assemble different components together.
The operation of the sealing device 10 may be described as follows. The liquid sulphur is received from the inlet 26 into the first chamber 18. From the first chamber 18, liquid sulphur flows towards the second chamber 20 via the first passage 40. The liquid sulphur is accumulated in the first chamber 18 till the pressure of the liquid suplhur is enough to lift the stopper 60 placed on the second end 44 of the first tube 38. Once the stopper 60 is lifted, the liquid sulphur flows towards the second chamber 20 via the second passage 54 and gets collected in the second chamber 20. The liquid sulphur collected in the second chamber 20 is degassed using the sparger 62. The sparger 62 is fed with pressurized gas, e.g. air, for introducing gas bubbles in the liquid suplhur for degassing of the liquid sulphur. The bubbling agitates the sulphur and helps in releasing the hydrogen sulphide gas associated with the liquid sulphur.
The hydrogen sulphide gas gets collected towards the upper end 32 of the second chamber 20 and is generally vented out to an incinerator through the vent 36. The degassed liquid sulphur is discharged from the sealing device 10 via the outlet 34. During continuous operation of the sealing device 10, the stopper 60 acts as a seal for blocking passage of any gases between the upstream condenser and downstream sulphur pit. The whole arrangement may be steam jacketed to maintain the sulphur in liquid state. Further, viewing ports 66 may be provided on the sealing device, for example in the housing, for monitoring the sealing and degassing procedure in the sealing device 10. The viewing ports 66 may be fitted with a transparent glass for facilitating viewing in the sealing device 10.
Further, present disclosure provides for a method for sealing and degassing of sulphur in a sealing device 10. The method includes providing a sparger 62 in the

second chamber 20 of the sealing device 10 as described above for degassing of the liquid sulphur in the second chamber 20 and venting the gases collected in the second chamber 20 through the vent 36.
The sealing device 10 in accordance with the present disclosure provides for an integrated degassing system in the sealing device 10, thereby eliminating the need of a separate degassing system. Further, the sealing device 10 in accordance with the present disclosure is easy to service and repair as different components may be dismantled after removing the top cover 30.
The sealing device 10 as described herein may be placed above the ground. Further, during maintenance, the sealing device 10 can be dismantled and reassembled at the installation site itself, thereby eliminating cumbersome, time consuming and expensive maintenance. Also, the sealing device 10 in accordance with the present disclosure is simple in construction and may provide for a cost effective sealing solution.
While preferred aspects and an example configuration have been shown and described, it is to be understood that various further modifications and additional configurations will be apparent to those skilled in the art. It is intended that the specific embodiments and configurations herein disclosed are illustrative of the preferred nature of the invention, and should not be interpreted as limitations on the scope of the invention.

List of Reference Numerals
Sealing device 10
Housing 12
Longitudinal axis 14
Separator 16
First chamber 18
Second chamber 20
Bottom 22
Top 24
Inlet 26
Debris removal opening 28
Top cover 30
Upper end 32
Lower end 33
Outlet 34
Vent 36
First tube 38
First passage 40
First end 42
Second end 44
Second tube 46
Top end 48
Bottom end 50
Guiding vane 52
Second passage 54
Inner wall 56
Outer wall 58
Stopper 60
Sparger 62
Tie rod 64
Viewing port 66
Source of pressurized gas 68

WE CLAIM:
1. A sealing device (10) for sealing liquid sulphur, the sealing device (10)
comprising:
a first chamber (18) adapted to receive liquid sulphur;
a second chamber (20) positioned above the first chamber (18) and configured to receive liquid sulphur from the first chamber (18);
a first tube (38) having a first end (42) fluidly connected to the first chamber (18) and a second end (44) positioned towards an upper end (32) of the second chamber (20), the first tube (38) fluidly connecting the first chamber (18) to the second chamber (20);
a second tube (46) positioned in the second chamber (20), the second tube (46) positioned over and at least partially receiving the first tube (38), the second tube (46) having a bottom end (50) positioned vertically above the first end (42);
a sparger (62) provided towards a lower end of the second chamber (20); and
an outlet (34) provided in the second chamber (20), the outlet (34) positioned vertically above the bottom end (50) of the second tube (46).
2. A sealing device (10) as claimed in claim 1, wherein the second end (44) is configured for placing a stopper (60).
3. A sealing device (10) as claimed in claim 1, wherein the sparger (62) is placed vertically below the bottom end (50).
4. A sealing device as (10) claimed in claim 1, wherein the sparger (62) is a perforated metal tube.
5. A sealing device (10) as claimed in claim 1, wherein the sealing device (10) further comprises a cylindrical housing (12) and a separator (16)

placed in the housing (12) defines the first chamber (18) and the second chamber (20).
A sealing device (10) as claimed in claim 5, wherein the sealing device (10) further comprises a removable top cover (30) capping a top portion of the sealing device (10).
A sealing device (10) as claimed in claim 1, wherein the sealing device (10) is provided with at least one viewing port (66).
A sealing device (10) as claimed in claim 1, wherein the stopper (60) is coupled to a guide for guiding movement of the stopper (60) on the second end (44).
A sealing device (10) as claimed in claim 1, wherein the second chamber (20) is provided with a vent (36) towards the upper end (32) of the second chamber (20) for venting of gas from the second chamber (20).
A sealing device (10) as claimed in claim 6, wherein the sparger (62), the first tube (38), the second tube (46) and the separator (16) are detachable for maintenance of the sealing device (10).
A method for operating the sealing device (10) as claimed in claim 1, the method comprising:
providing pressurized liquid sulphur in the first chamber (18);
providing pressurized gas in sparger (62) placed the second chamber (20); and
receiving degassed liquid sulphur from the outlet (34).