FR3131617A3 - CONNECTOR WITH PRESSURIZED SEAL CHAMBER FOR TUBULAR FURNACE PROCESSING TUBE - Google Patents

Abstract

CONNECTOR WITH PRESSURIZED SEAL CHAMBER FOR TUBULAR FURNACE PROCESS TUBE A connector (12) for a process tube (8), comprising an annular body (18); an engagement bore (42) formed in the annular body (18), to receive one end of the treatment tube (8); a sealing groove (20) formed in the engagement bore, to receive at least two seal rings (22) to contact the end of the process tube (8); wherein the annular body (18) includes a seal port (28) in fluid communication with the seal groove (20) so as to allow application of gas pressure to the seal groove (20 ) between the at least two annular seals (22). (Figure to be published with abstract: Figure 2)

Description

CONNECTOR WITH PRESSURIZED SEALING CHAMBER FOR TUBULAR FURNACE PROCESSING TUBE

The invention relates to the field of gaseous processes in a treatment tube, for example in the presence of heat and/or vacuum. More specifically, the invention relates to the connection of a processing tube of a processing tube machine, such as, for example, a tube furnace, to a process gas supply.

A laboratory process tube furnace generally includes a frame equipped with electrical resistors and temperature control equipment, and an insulated cover hinged to an upper portion of the frame. The cover and the frame form a transverse passage for receiving a treatment tube. The latter is generally made of a material resistant to high temperatures such as alumina. The treatment tube forms an internal passage intended to receive a substrate and a treatment gas in order to carry out reactive and/or thermal treatments. A connector, or sealing flange, is mounted at each end of the treatment tube so as to sealingly isolate its interior passage from the environment and to inject one or more treatment gases therein. Due to the potentially very high temperatures of the above process, e.g. above 1000°C, the processing tube material is refractory material like alumina ceramic, where the processing tube is made by powder technology. Due to this manufacturing process, the outer surface of the processing tube can have a large geometric tolerance as well as large surface finish tolerances. This means that the connectors, or sealing flanges, fitted to the ends of the processing tube may have weaknesses in sealing with the exterior surface of the processing tube.

The prior art patent document published US 2003/0015142 A1 discloses a reaction tube made of quartz and provided with a connector in the form of a sleeve engaging sealingly with said tube by means of O-rings located between a surface outer surface of the tube end and an inner surface of the sleeve-shaped connector receiving said tube end. The sleeve-shaped connector includes a water line to cool the O-rings. Despite the useful cooling action of the water pipe, the engagement between the O-rings and the tube can present defects, i.e. leaks, mainly due to the dimensional and surface tolerances of manufacture of the tube.

The invention has the objective or technical problem of overcoming at least one of the disadvantages of the aforementioned prior technique. More particularly, the invention aims to provide a secure and tolerance-resistant connection to a treatment tube, that is to say a tube intended to serve as a reaction chamber in the presence of gas, particularly at high temperature. .

A connector for a treatment tube, comprising an annular body; an engagement bore formed in the annular body for receiving one end of the processing tube; a sealing groove formed in the engagement bore, intended to receive at least two annular seals intended to come into contact with the end of the processing tube; wherein the annular body includes a sealing port in fluid communication with the sealing groove so as to permit the application of gas pressure in the sealing groove between the at least two annular seals.

According to a preferred embodiment, the connector further comprises the at least two annular seals in the sealing groove, said annular seals preferably being two O-rings.

According to a preferred embodiment, the connector further comprises a rigid ring located in the sealing groove between the at least two annular seals.

According to a preferred embodiment, the ring comprises a series of radial holes extending from a radially outer face to a radially inner face of said ring, said radial holes being distributed, preferably uniformly, along a circumference of said ring.

According to a preferred embodiment, the annular body further comprises a stop bore adjacent to the engagement bore and intended to abut against the end of the treatment tube when said treatment tube is received in the bore engagement, and a processing gas connection port opening into the abutment bore.

According to a preferred embodiment, the abutment bore forms an opening giving access to the treatment tube when said treatment tube is received in the engagement bore.

According to a preferred embodiment, the connector further comprises a closing plate removably mounted on the annular body in the vicinity of the stop bore, so as to close the opening.

According to a preferred embodiment, the annular body further comprises a cooling chamber surrounding the sealing groove, a cooling inlet port and a cooling outlet port, said ports being fluidly connected to the cooling chamber for the circulation of a cooling fluid.

According to a preferred embodiment, the annular body comprises a first annular part forming the engagement bore and the sealing groove, and a second annular part in engagement with the first annular part, the cooling chamber being delimited by the first and second annular pieces.

According to a preferred embodiment, at least one of the first and second annular parts comprises a groove forming the cooling chamber.

According to a preferred embodiment, at least one of the cooling inlet and cooling outlet ports is formed on one of the first and second annular parts.

Also provided is a processing unit comprising an alumina processing tube with two ends; and a connector sealingly mounted on each end of the treatment tube; in which at least one of the two connectors conforms to the invention.

Also provided is a processing tube machine, comprising a processing control unit; and a processing unit extending through the processing control unit; in which the processing unit conforms to the invention.

According to a preferred embodiment, the process tube machine comprises a process gas flow control unit with at least one process gas inlet and a process gas outlet; a neutral gas flow control unit with at least one neutral gas inlet and one neutral gas outlet connecting to the process gas flow control unit.

Advantageously, the neutral gas outlet is fluidly connected to the sealing port of each of the at least one connector.

According to a preferred embodiment, the neutral gas flow control unit is configured to apply neutral gas pressure to the sealing port of the connector of the processing unit and to detect a potential decrease in said gas pressure neutral in said connector and deliver an alarm in the event of a drop detected.

The invention also relates to a gaseous process comprising the following steps: (a) placing a substrate in a processing tube; (b) injection of at least one treatment gas into the treatment tube; wherein steps (a)-(b) are carried out using a processing tube machine according to the invention, and at least during step (b), a neutral gas is supplied to at least l one of the two connectors, so as to apply a neutral gas pressure to the sealing groove of said at least one connector.

According to a preferred embodiment, at least one treatment gas of step (b) comprises a reactive gas.

Advantageously, the neutral gas is nitrogen and/or argon.

According to a preferred embodiment, the pressure of the neutral gas is greater than a pressure of the treatment gas in the treatment tube, preferably by at least 0.1 bar, more preferably by at least 0.5 bar.

According to a preferred embodiment, the pressure of the neutral gas is at least 0.5 bar and/or a maximum of 2 bar.

Advantageously, the gaseous process further comprises an intermediate step of heating the treatment tube such that an interior of the treatment tube reaches a temperature of at least 100°C, preferably at least 200°C. .

According to a preferred embodiment, the pressure of the neutral gas is monitored so as to detect a potential drop in said pressure at least during step (b) and to emit an alarm in the event of detection of the drop.

The invention is particularly interesting in that it makes it possible to obtain gas tightness in the presence of large manufacturing tolerances of the treatment tube. It also increases the safety of the process tube machine when in operation when using reactive gases as the process gas. These large manufacturing tolerances are essentially due to the use of particular material for the production of the treatment tube, such as ceramic, which is difficult to machine. Additionally, operating the process tube with potentially hazardous gases and also at high temperatures increases the dangerous consequences of a process gas leak. It is understood, however, that the invention remains advantageous at room temperature or at moderate temperatures such as above room temperature and up to 100°C or 200°C, essentially because the safety in terms of gas tightness between the connector and the process tube is ensured at any temperature.

is a perspective view of a processing tube machine according to the invention;

is a detail view of one end of the processing tube of the tube processing machine of the , according to the invention;

is a longitudinal sectional view of the end of the treatment tube of the ;

is a perspective view of the ring located in the sealing groove of the connector, visible in Figures 2 and 3;

is a schematic illustration of the fluidic connections of the processing tube machine according to the invention.

detailed description

There represents a tube processing machine, said machine being able to be a tubular furnace, equipped with a heat treatment unit, according to the invention.

The processing tube machine 2 comprises a chassis 4 housing various components such as a power supply, processing gas supplies, a temperature control unit, etc.

The processing tube machine 2 also includes a heating unit 6 carried by the frame 4 and powered and controlled by the aforementioned power supply unit and temperature control unit, respectively. The heating unit 6 is made up of two half-shells housing electrical resistances and insulating material. The two half-shells are movable relative to each other so as to give access to a cavity of the heating unit 6, for example to allow the installation of the treatment tube 8. For example, the upper half-shell can be lifted or removed from the lower half-shell so as to give access to a tubular cavity intended to receive and house the treatment tube 8. It will be mentioned that the treatment tube 8 can also be inserted into the cavity while the heating unit 6 generally remains closed or by means of a completely closed heating cavity, by a longitudinal sliding movement of the treatment tube 8 in the tubular cavity. As is apparent, the tubular cavity opens at each end thereof at the level of the two opposite side walls of the heating unit 6. In other words, the treatment tube 8, when correctly positioned functionally in the heating unit 6, extends out of said heating unit at both ends of said treatment tube 8.

The processing tube machine 2 further comprises a cover 10 hinged on the frame 4. The cover 10, when closed, i.e. in the lowered position, covers the heating unit 6 and parts of the treatment tube 8 extending out of the treatment unit 6, essentially to avoid contact of an operator with the treatment tube 8 and/or the heating unit 6 potentially at very high temperatures.

In the processing tube machine shown on the , the processing tube 8 extends horizontally, so the processing tube machine is of the horizontal type. It is worth mentioning that the processing tube machine can be of the vertical type, that is, where the processing tube extends vertically. The treatment tube can also be tilted.

The treatment tube 8 is made of a refractory material, in order to withstand high temperatures, e.g. at least 600°C, preferably at least 1000°C. The treatment tube 8 is advantageously made of ceramic alumina. The treatment tube can also be made of quartz or glass. The treatment tube 8 is hollow so as to be able to receive a substrate intended to undergo treatment at high temperature and/or possibly in the presence of neutral and/or reactive gases.

Still with reference to the , it can be seen that a connector 12 is provided at each of the ends of the treatment tube 8. The treatment tube 8 equipped with the two connectors 12 at its two ends forms a gas treatment unit 14. The connectors ensure gas-tight connection between the interior of the tube and the gas conduits 16. The connectors 12 must provide a gas-tight connection with the processing tube 8 in order to prevent leakage of potentially explosive gases or to prevent air ambient to circulate in the tube 8. This gas-tight connection is achieved by appropriate contact of the joints in the connectors with the exterior cylindrical surface of the treatment tube 8. The latter being made of a refractory material is non-metallic and cannot therefore not be easily machined. It also has geometric dimensions with a certain tolerance, a consequence of its manufacturing process.

There is a perspective view of one end of the gas treatment unit 14 visible on the treatment tube machine 2 of the .

There shows a sectional view of the connector 12. The sectional view is along two longitudinal planes of the treatment tube 8, which means that the latter is cut in its longitudinal direction by two planes comprising the longitudinal axis of the treatment tube.

As is apparent, the connector 12 comprises an annular body 18 forming an engagement bore receiving the end of the treatment tube 8. A sealing groove 20 is formed in the engagement bore, so as to be directly adjacent to an outer cylindrical surface of the processing tube 8. The sealing groove 20 houses two annular seals 22 in contact with the outer cylindrical surface of the processing tube 8. The annular body 18 includes a sealing port 34, in communication fluidic with the sealing groove 20 so as to allow the application of a gas pressure in the sealing groove 20 between the two annular seals 22. The sealing groove 20 with the two annular seals 22 then forms a chamber which can be pressurized to ensure and/or control a leak-free connection between the annular body 18 and the treatment tube 8.

Still with reference to the , we can observe the presence of a groove forming a cooling chamber 24 to maintain the two annular seals 22 at a limited temperature. A cooling inlet port 36 and a cooling outlet port 38 are formed on the body 18. These two ports are for example diametrically opposed, it being understood, however, that another relative angular position can be considered.

Furthermore on the , it can be observed that the annular body 18 includes an abutment bore 26 directly adjacent to the engagement bore, for abutting against the end of the processing tube 8 when received in the engagement bore. The annular body 18 may further include a process gas port 28 directly fluidly connected to a passage (not visible on the ) formed in the annular body 18 which opens into the stop bore 26.

The stop bore 26 forms an opening providing direct access to the interior of the processing tube 8. A closure plate 32 is removably mounted on the annular body adjacent to the stop bore 26, so as to close the opening and thus close the interior of the processing tube 8. The closure plate is mounted by means of a series of screws along its periphery, extending through the closure plate and engaging in holes, for example threaded holes, formed in the annular body 18, it being understood, however, that other fixing means can be envisaged.

The connector 12 therefore provides a process gas connection to the process tube 8 which is gas tight due to the sealing groove which can be pressurized so as to axially bias the annular seals against the side walls of the sealing groove and also so as to form a barrier against possible leaks of the process gas into the ambient air. For this purpose, the sealing groove is advantageously pressurized with a neutral gas such as nitrogen and/or argon, so that in the event of a possible gas leak between the treatment tube 8 and the fitting 12, the gas under pressure in the sealing groove, provided that it is at a pressure higher than the pressure in the processing tube 8, will flow into the processing tube 8 instead of the processing gas potentially dangerous flows from the treatment tube 8 towards the ambient air.

The seals are for example O-rings but it is understood that other types of seals can be considered, such as annular seals with different sections, such as square type sections, oval sections, sections with one or more lips of waterproofing, etc.

During operation, i.e. during a gas-reactive process and/or a heat-reactive process with the gas processing unit 14, the pressure of the neutral gas is advantageously kept higher than the gas pressure treatment inside the treatment tube, so as to maintain the effect of axial stress of the seals against the side walls of the sealing groove. The pressure difference can be at least 0.1 bar or even 0.5 bar. The neutral gas pressure does not need to be constant; it can vary over time during the process. Additionally, the neutral gas pressure can be monitored before and/or during the process to detect any leaks and issue an alarm when an abnormal pressure drop is detected.

Figures 3 and 4 are more detailed views of connector 12.

There is a longitudinal sectional view of the . It can be observed that the annular body 18 is made up of a first annular part 18.1 forming the sealing groove 20, the engagement bore 42 and the stop bore 26, and a second annular part 18.2 engaging with the first annular part 18.1, the cooling chamber 24 being delimited by the first and second annular parts 18.1 and 18.2. For example, the cooling chamber 24 is formed by a circular groove of cylindrical shape extending axially and opening onto a front face of the first annular part 18.1 of the body 18, this opening being closed by an annular plate 25 held against the first annular part 18.1 of the body 18 by the second annular part 18.2 thereof. The latter cooperates with the first annular part by means of axial screws (not visible).

As can be seen, the sealing port 34 is in fluid connection with the sealing groove 20 via a passage formed in the annular body 18, for example in the first annular part 18.1. A ring 40 is located in the sealing groove 20, between the two annular seals 22. This ring 40 forms a spacer maintaining the two annular seals substantially in their extreme position. The seal groove 20 includes two lateral annular side walls against which the annular seals 22 are biased or rest when fluid pressure is applied via the seal port. For example, one of these two opposite side walls is formed by a shoulder portion on the first annular part 18.1 while the other is formed by the second annular part 18.2. It is understood that other constructions may be considered while achieving the above architecture and functions.

Still with reference to the , we see that the cooling chamber 24 is delimited between the first and second annular parts 18.1 and 18.2, these two annular parts being mutually engaged in a liquid-tight manner.

The cooling chamber 24 at least partially surrounds the sealing groove 20, so as to cool and protect the annular seals 22 as best as possible. The cooling chamber 24 can, however, be more or less axially offset relative to the sealing groove. waterproofing 20 while ensuring a satisfactory refreshing effect.

There is a perspective view of a part of the ring 40 located in the sealing groove 20 between the annular seals 22 of Figures 5 and 6. The ring 40 is made of a rigid material such as plastic, metal or a combination of these. The ring may have a rectangular cross section. It shows an outer circular face 40.1 and an inner circular face 40.2. The ring 40 can be provided with a series of holes 40.3 forming passages between the external circular face 40.1 and the internal circular face 40.2.

There is a schematic illustration of the fluidic connections of the processing tube machine according to the invention.

The process tube machine 2 may include a process gas flow control unit 44 with at least one process gas inlet 44.1 and a process gas outlet 44.2 connected to the process gas port 28 of one connectors 12. Such a process gas flow control unit 44 may include flow and pressure control means to provide an appropriate flow of process gas at a desired pressure. The treatment gas may be a reactive gas such as oxygen.

The processing tube machine 2 may also include a neutral gas flow control unit 46 with at least one neutral gas inlet 46.1 and one neutral gas outlet 46.2 fluidly connected to the seal port 34 of at least one of the two connectors 12. The neutral gas flow control unit 46 can also be fluidly connected to the process gas flow control unit 44 so as to supply said gas flow control unit. treatment gas 44 into neutral gas. The neutral gas flow control unit 46 may include flow and pressure control means for providing an appropriate pressure of the neutral gas, e.g. nitrogen, to connector(s) 12. The appropriate pressure can be between 1 and 2 bar. The neutral gas flow control unit 46 may be configured to apply neutral gas pressure to the connector sealing port of the processing unit and also to detect a potential decrease in said neutral gas pressure in said connector and to emit an alarm in case the decrease is detected.

The processing tube machine 2 may also include a cooling circuit 48 which is fluidly connected to the cooling inlet port 36 and the cooling outlet port 38 of at least one of the connectors 12. The cooling circuit may include a liquid as the cooling fluid, while a gas may also be considered. The cooling circuit 48 is shown schematically as comprising a circulation pump and a heat exchanger, for reasons of clarity. It is understood, however, that the cooling circuit(s) 48 may be different, that is to say more complex or operating with another principle. By way of example, the cooling circuits 48 can be open circuits supplied by a fluid source and releasing the heated fluid leaving the connections towards the ambient air or towards an evacuation conduit such as a water evacuation conduit. water in a building.

The process gas port 28 of the connector 12 other than that supplied with process gas can be fluidly connected to a vacuum pump and can flow to a collection unit 52 where the waste process gas(es) are treated and/or released into the ambient air.

Claims (10)

Connector (12) for a treatment tube (8), comprising:
- an annular body (18);
- an engagement bore (42) formed in the annular body (18), intended to receive one end of the treatment tube (8);
- a sealing groove (20) formed in the engagement bore (42), intended to receive at least two annular seals (22) intended to come into contact with the end of the treatment tube (8);
characterized in that
the annular body (18) includes a sealing port (28) in fluid communication with the sealing groove (20) so as to permit the application of gas pressure in the sealing groove (20) between the at least two annular seals (22). Connector (12) according to claim 1, further comprising the at least two annular seals (22) in the sealing groove (20), and a rigid ring (40) located in the sealing groove (20). ) between the at least two annular seals (22). Connector (12) according to one of claims 1 and 2, wherein the annular body (18) further comprises an abutment bore (26) adjacent to the engagement bore (42) and intended to abut against the end of the treatment tube (8) when said treatment tube (8) is received in the engagement bore (42), and a treatment gas port (28) opening into the abutment bore (26 ) ; preferably, the stop bore (26) forms an opening giving access to the treatment tube (8) when said treatment tube (8) is received in the engagement bore; and more preferably, the connector (12) further comprises a closing plate (32) removably mounted on the annular body (18) in the vicinity of the stop bore (26), so as to close the opening. Connector (12) according to one of claims 1 to 3, in which the annular body (18) further comprises a cooling chamber (24) surrounding the sealing groove (20), an inlet port of cooling (36) and a cooling outlet port (38), fluidly connected to the cooling chamber (24) for the circulation of a cooling fluid, preferably the annular body (18) comprises a first annular part ( 18.1) forming the engagement bore (42) and the sealing groove (20), and a second annular part (18.2) in engagement with the first annular part (18.1), the cooling chamber (24) being delimited by the first and second annular parts (18.1, 18.2), more preferably at least one of the first and second annular parts (18.1, 18.2) comprises a groove forming the cooling chamber (24). Processing unit (14) comprising:
- an alumina treatment tube (8) with two ends; And
- a connector (12) mounted in a sealed manner on each of the ends of the treatment tube (8); in which at least one of the two connectors (12) is according to one of claims 1 to 4. Processing tube machine (2) comprising:
- a processing control unit (6); And
- a processing unit (14) extending through the processing control unit (6);
characterized in that the processing unit (14) is according to claim 5. Processing tube machine (2) according to claim 6, comprising:
- a process gas flow control unit (44) with at least one process gas inlet (44.1) and one process gas outlet (44.2);
- a neutral gas flow control unit (46) with at least one neutral gas inlet (46.1) and one neutral gas outlet (46.2) connecting to the process gas flow control unit (44) ;
and in which, preferably, the neutral gas outlet (46.2) is fluidly connected to the sealing port (28) of each of the at least one connector (12). A processing tube machine (2) according to claim 7, wherein the neutral gas flow control unit (46) is configured to apply neutral gas pressure to the sealing port (28) of the connector (12) of the processing unit (14) and to detect a potential decrease in said neutral gas pressure in said connector (12) and deliver an alarm in the event of a detected drop. Gaseous process comprising the following steps:
(a) placing a substrate in a processing tube (8);
(b) injection of at least one treatment gas into the treatment tube (8);
in which steps (a)-(b) are carried out using a processing tube machine (2) according to one of claims 6 to 8, and at least during step (b), a neutral gas is supplied to at least one of the two connectors (12), so as to apply a neutral gas pressure to the sealing groove (20) of the at least one connector (22). Gaseous process according to claim 9, wherein the pressure of the neutral gas is greater than a pressure of the process gas in the process tube (8), preferably at least 0.1 bar, more preferably at least 0. .5 bar, and the pressure of the neutral gas is monitored so as to detect a potential drop in said pressure at least during step (b) and to emit an alarm if the drop is detected.