AU2015341098A1

AU2015341098A1 - Sealing system for a container closure

Info

Publication number: AU2015341098A1
Application number: AU2015341098A
Authority: AU
Inventors: Volker Deisinger
Original assignee: Air Liquide SA; LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
Current assignee: LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
Priority date: 2014-10-31
Filing date: 2015-10-08
Publication date: 2017-06-01
Anticipated expiration: 2035-10-08
Also published as: DE102014115915A1; WO2016066277A1; CN105567334B; AU2015341098B2; CN105567334A; CN205295243U

Abstract

A sealing system for a container closure, comprising a first and a second sealing surface and at least two concentric seals connected with one sealing surface each or formed by the design of one of the sealing surfaces, wherein the sealing surfaces and the seals are designed and arranged relative to each other such that in the closed condition of the sealing system both seals are exposed to the closing pressure with which the sealing surfaces are pressed against each other, wherein a gas-tight space is formed.

Description

Sealing System for a Container Closure 'Field of the Invention V/';:'/;/:TY:. /This invention relates to a.sealing system for a.container closure, comprising a .first and a second sealing surface and at least two concentric seals connected with one sealing surface each or formed by the design of one of the sealing surfaces. The sealing system according to the invention is suitable in particular for use in a coal lock and/or ash lock of a fixed-bed pressure gasification reactor for producing synthesis gas by converting carbonaceous fuels, for example coal, coke or lumpy biomass, with gasification media.

The invention furthermore relates to a method for leak testing of a lock closure . equipped with the sealing system according to the invention. ...

Prior art

The document DE 4041445 AT; shows the basic: construction of . a : closure frequently used for fixed-bed pressure gasification reactors. This type of closures consists of a seat with a circular opening and a conical or frustoconical closing body. The circumference of the opening of the seat comprises a circumferential edge which forms the sealing surface against which the closing body is pressed 'for closing the closure.',,.'.

One problem for the tightness of closures of containers, locks and reactors which . are charged with lumpy material, such as e.g. coal or coke, is the soiling of the sealing surface with the lumpy material. It frequently occurs that rests of the lumpy material are deposited on the sealing surface or on the closing body and thus prevent tight closing.

The patent specification DE 32 39 841 C2 describes a conical closure which is equipped with a nozzle by means of which deposits are to be blown off from the sealing surface on closing of the closure. The actual seal is made of metal, and ' :... for additionally sealing the closure this Invention provides a lip seal of flexible material which is installed on the pressure side, concentric to the metallic main seal. The lip seal is formed such that it is not pressed between metal surfaces, but .', by the gas pressure merely is pressed against the conical surface of the sealing body.

Since the process gases, which the closures are to retain in the containers or the reactors, often are harmful to health and the environment, it is important to check the tightness of the closure. In a lock for charging a reactor under overpressure,^ . ... as it is shown in the documents DE 4041445 A1 and WO 2014/026908 A1, the . tightness of the closure located between reactor and lock can be tested in that theV. upper closure of the lock directed to the atmosphere also is closed and the pressure in the lock is observed. Due to the reactor pressure lying distinctly above atmospheric pressure, an increase in pressure indicates a leakage of the lower closure directed to the reactor. Correspondingly, the tightness of the upper lock . closure can be tested in that the lock is put under overpressure, if possible with a .. harmless gas. A pressure drop then indicates a leakage of the upper closure. This test method on the one hand is very time-consuming and on the other hand unreliable, because of the large volume of the lock, as a constancy of the lock pressure also would be observed when both closures were leaky to the same extent.

Therefore, it is the object of the invention to provide a sealing system for 3 ////. . . : .. . container closure, whose tightness can be tested reliably and with little .''expenditure of time.

Description of the Invention

The object is solved with the invention according to claim .1 for a sealing system according to the invention, according to claim 8 for a use of the sealing system, and according to claim 9 for a method for leak testing by using the sealing system according to the invention. . The sealing system according to the invention for a container closure comprises a first.and a second sealing surface and at least two concentric seals connected with one sealing surface each or formed by the design of one of the sealing surfaces, wherein the sealing surfaces and the seals are designed and arranged relative to each other such that in the closed condition of the sealing system a gas-tight space is formed by the sealing surfaces and the seals, which also remains gas-tight when the gas pressure existing in the same is greater than the ambient pressure.

The sealing system is designed such that both seals are exposed to the closing pressure with which the sealing surfaces are pressed against each other and in . the closed condition a gas-tight space is formed by the sealing surfaces and the .'seals,...

Preferred Aspects of the Invention A preferred aspect of the invention.is characterized in that the seals.have a circular, oval, semicircular or approximately triangular cross-section tapered on the opposite side of the mounting surface. Due to this design, the contact surface of the seal with the opposite sealing surface is kept small, whereby deposits present on the sealing surface can impair the tightness less strongly. The same pressing force , also results in a higher pressure against the opposite. sealing >.. surface as compared to seals with larger contact surface.

It may be advantageous to. provide further seals in addition to the at least two . . . . . seals, which likewise are arranged concentrically, but further inside and further .. outside in radial direction with respect to the first seals. As seals of the described . . .. type are subject to wear, spare seals thus are provided, in order to ensure the safe closing of the container. A further preferred aspect of the invention is characterized in that the seals are dimensionally stable, but elastically deformable. In this way, it is avoided that the seal is squeezed between sealing surface and.closing body, wherein it is still possible, however, to compensate slight structural inaccuracies of the closure and slight deposits on the sealing surface by a deformation of the seal.

Another preferred aspect of the invention is characterized in that the seals can be moved into the interior of the component carrying the sealing surface and the. . seal, in order to protect it against heat and abrasive media. In this way, the useful.: .. . life of the seals is extended. A-'further preferred aspect of the invention is characterized in that the . sealing surfaces can be cooled by means of a cooling medium. By this measure, too, the useful life of the seals is extended. . Another preferred aspect of the invention is characterized in that at least one of. the sealing surfaces between the seals is provided with a first opening which is designed such that a fluid can be delivered through the first opening or a device for measuring the pressure or the temperature can be introduced into the gas-tight space formed by the sealing surfaces and the seals.

Another preferred aspect of the invention is characterized in that at least one of the sealing surfaces between the seals is provided with a first and with a second opening, wherein the device for measuring the pressure or the temperature has.. been introduced through the first opening and the second opening is connected with a feeding device for a fluid, such as a purge gas, or a liquid, such as water, and wherein the first and the second opening are in fluid connection with the same gas-tight space. This creates the possibility for testing the tightness of the sealing system,·.

The first and the second openings advantageously also can be used to introduce and discharge a gas or a liquid as flushing medium, in order to clean the seals and/or the spaced formed by the sealing surfaces and the seals. Due to the higher impulse force the use of liquids, for example water, is recommendable here.

It is also possible to introduce a fluid as blocking medium into the space formed by the sealing surfaces and the seals. The blocking medium, which has a- ...... .. pressure that lies above the process pressure of the container or reactor, then prevents that process gas gets into the atmosphere in the case of a leakage of the seals. As a certain amount of blocking medium gets into the container or reactor, the blocking medium must be selected such that it does not disturb the process.

The sealing system according to the invention is suitable in particular for use in a . coal lock and/or ash lock of a fixed-bed pressure gasification reactor for producing. . . synthesis gas by converting carbonaceous fuels, for example coal, coke or lumpy biomass, with a gasification medium, comprising oxygen and steam. This use . involves the problem of deposits on the sealing surface, of the closure to a particularly large extent and at the same time the tightness of the closure is particularly important because of the harmfulness of the process gases occurring here, namely of the synthesis gas constituents carbon monoxide and hydrogen.., . ...

The method according to the invention for leak testing of the lock closure of the fuel lock or ash lock in a fixed-bed pressure gasification reactor comprises the following steps: a) providing a fixed-bed pressure gasification reactor with a coal lock or ash lock, wherein the coal lock or the ash lock or both is/are equipped with a sealing · : . system according to any of the aforementioned claims, b) filling the fuel into the fuel lock or draining the ash from the ash lock, c) closing the fuel lock . or the ash lock'by joining .the first and second .sealing surfaces, d) measuring the pressure in the gas-tight space formed by the sealing surfaces . and the seals with a pressure measuring device introduced through a first opening during closing of the lock and during a time period t after closing of the lock, e) comparing the increase in pressure during closing and the pressure drop after closing during the time period t with a pressure Increase setpoint and a pressure drop setpoint, wherein a tightness of the lock is assumed when the measured pressure increase is greater than the pressure increase setpoint and/or the. measured pressure drop is smaller than the pressure drop setpoint.

According to the prior art, the pressure of the lock space has been monitored so ; far for checking the tightness. Because of the size of this space, the pressure fluctuations are small in the case of smaller leakages and only are detectable after an extended measuring time.

On the other hand, the spaced formed by the sealing surfaces and the seals, which is monitored during the leakage test according to the invention, is small, so that small leakages already lead to distinctly recognizable fluctuations of the pressure. Since the testing time for the leakage test thus has been shortened, production·time hence is gained.;',. A particular aspect of the method for leak testing is characterized in that after closing of the lock a purge gas is introduced into the same gas-tight space via a. second opening, until the target pressure p is reached and the measurement of the pressure drop is made proceeding from the target pressure p. In this way, a harmless purge gas can be used, which in the case of a leakage of the sealing. .. system can escape into the environment without danger.

Alternatively, the gas-tight space also can be evacuated via the second opening by means of a vacuum pump, wherein subsequently the pressure increase is . tracked in terms of time with the pressure measuring device, in order to infer they, tightness in this way. . ..

In another particular aspect, the method according to the invention for leak testing of the lock closure of the fuel lock or ash lock in a fixed-bed pressure gasification. . . reactor comprises the following steps: a) providing a fixed-bed pressure gasification reactor with a coal lock or ash lock, wherein the coal lock or the ash lock or both is/are equipped with a sealing system according to the invention, b) filling the fuel into the fuel lock or draining the ash from the ash lock, ' c) closing the fuel lock or the ash . lock by joining the first and second .sealing .... . ... surfaces,..;. d) supplying a purge gas into the gas-tight space formed by the sealing surfaces . and the seals by using a feeding device which is connected with a first Opening,::' wherein the feeding device comprises a conduit and a flow measuring device, e) measuring the flow rate when supplying the purge gas by using the flow measuring device, wherein a tightness of the lock is assumed, when the measured flow rate falls to zero when the purge gas is supplied. ....

Due to this design of the method according to the invention the measurement of the pressure in the space formed by the sealing surfaces and the seals and the access to this space necessary for the pressure measurement can be omitted.

It is also possible to admix a test gas, such as helium, to the purge gas in step d) and to install detectors for the test gas behind the sealing system, in particular in direction of the atmosphere. When using helium as test gas, the measurement by means of mass spectrometry for example can be used advantageously. In this way, a leakage would be detected. A flow measurement of the purge gas can be omitted in this aspect of the invention.

Exemplary embodiment -T..

Further features, advantages and possible applications of the invention can also be taken from the following description of an exemplary embodiment and the . : drawing. All features described and/or illustrated form the subject-matter of the invention per se or in any combination, independent of their inclusion in the claims or their back-reference, ......

In the only Figure";; .. Fig. 1 :.,. . shows a schematic representation of a prOferred'c^'rifigura.tibn the·.·.·.:·'.··'.·:-·'::'.:.'· . sealing system according to the invention..... ..The invention will now be explained with reference to the drawing, :: .. . :: The closure T serves for sealing the container space 2 against the filling space 3,.. : from which the non-iilustrated bulk material slips into the container space 2, when the closure 1 is open. The closured comprises the closure seat 4 and the closing .... body 5. In the top view, the closing body 5 has the shape of a cone or truncated............ cone with circular base. The closure seat 4 fittingly has an opening circular in the ... top view. The closing body 5 is attached to a rod 6 and is moved up and down by a non-iilustrated mechanism for opening and closing the closure 1. The first sealing surface 7 of the sealing system is provided by the closure seat 4, and the second sealing surface . 8 is provided by the closing body 5. On the sealing surface 7 the seals 9a and 9b are mounted concentrically to each other, which each have a triangular cross-section. They extend around the circumference of the closure seat 4 and thus in a top view have the shape of two concentrically . arranged rings. Via conduit 10 a fluid, e.g. an inert gas can be delivered into the space formed by the sealing surfaces 7,8 and the seals 9a and 9b, which has the. shape of an inclined circular ring with trapezoidal cross-section. Via line 11 the . .: pressure In this space can be measured. . . Industrial Applicability

The invention provides a sealing system for containers and reactors, whose tightness can be checked in a simple and effective way. Since the unwanted outflow of process gas generally must be.avoided for economic,and safety reasons, this invention is commercially applicable. Due to the methods for leak testing improved over those known from the prior art, the time period required for leak testing is shortened, whereby the availability of the plant, for example of the fixed-bed pressure gasification reactor, for the production is increased.

List of Reference Numerals 1 container closure 2 container space 3 filling space 4 closure seat 5 closing body 6 rod 7 sealing surface 8 sealing surface 9a, b seal 10 line for fluid supply 11 line for pressure measurement

Claims

Claims:

1. A seating system for a container closure 1, comprising a first and a second sealing surface 7, 8 and at least two concentric seals 9a, b connected with one sealing surface each or formed by the design of one of the sealing surfaces, characterized in that the sealing surfaces 7, 8 and the seals 9a, b are designed and arranged relative to each other such that in the closed condition of the sealing system both seals 9a, b are exposed to the closing pressure with which the sealing surfaces 7, 8 are pressed against each other, wherein a gas-tight space is formed by the sealing surfaces and the seals.
2. The sealing system according to claim 1, characterized in that the seals 9a, b have a circular, oval, semicircular or approximately triangular cross-section tapered on the opposite side of the mounting surface.
3. The sealing system according to claim 1 to 2, characterized in that the seals are dimensionally stable, but elastically deformable.
4. The sealing system according to claim 1 to 3, characterized in that the seals 9a, b can be moved into the interior of the component carrying the sealing surface and the seal, in order to protect it against heat and abrasive media.
5. The sealing system according to claim 1 to 4, characterized in that the sealing surfaces can be cooled by means of a cooling medium.
6. The sealing system according to claim 1 to 5, characterized in that at least one of the sealing surfaces between the seals is provided with a first opening which is designed such that a fluid can be delivered through the first opening or a device for measuring the pressure or the temperature can be introduced into the gas-tight space formed by the sealing surfaces and the seals.
7. The sealing system according to claim 6, characterized in that least one of the sealing surfaces between the seals is provided with a first and with a second opening, wherein the device for measuring the pressure or the temperature has been introduced through the first opening and the second opening is connected with a feeding device for a fluid, and wherein the first and the second opening are in fluid connection with the same gas-tight space.
8. Use of the sealing system according to any of the preceding claims in a coal lock and/or ash lock of a fixed-bed pressure gasification reactor for producing synthesis gas by converting carbonaceous fuels, for example coal, coke or lumpy biomass, with a gasification medium, comprising oxygen and steam.
9. A method for leak testing of the lock closure of the fuel lock or ash lock in a fixed-bed pressure gasification reactor, comprising the following steps: a) providing a fixed-bed pressure gasification reactor with a coal lock or ash lock, wherein the coal lock or the ash lock or both is/are equipped with a sealing system according to any of the aforementioned claims, b) filling the fuel into the fuel lock or draining the ash from the ash lock, c) closing the fuel lock or the ash lock by joining the first and second sealing surfaces, d) measuring the pressure in the gas-tight space formed by the sealing surfaces and the seals with a pressure measuring device introduced through a first opening during closing of the lock and during a time period t after closing of the lock, e) comparing the pressure increase during closing and the pressure drop after closing during the time period t with a pressure increase setpoint or pressure drop setpoint, wherein a tightness of the lock is assumed when the measured pressure increase is greater than the pressure increase setpoint and/or the measured pressure drop is smaller than the pressure drop setpoint.
10. The method according to claim 9, characterized in that after closing of the lock a purge gas is introduced into the same gas-tight space via a second opening, until a target pressure p is reached and the measurement of the pressure drop is made proceeding from the target pressure p.
11. A method for leak testing of the lock closure of the fuel lock or ash lock in a fixed-bed pressure gasification reactor, comprising the following steps: a) providing a fixed-bed pressure gasification reactor with a coal lock or ash lock, wherein the coal lock or the ash lock or both is/are equipped with a sealing system according to any of the aforementioned claims, b) filling the fuel into the fuel lock or draining the ash from the ash lock, c) closing the fuel lock or the ash lock by joining the first and second sealing surfaces, d) supplying a purge gas into the gas-tight space formed by the sealing surfaces and the seals with a feeding device which is connected with a first opening, wherein the feeding device comprises a conduit and a flow measuring device, e) measuring the flow rate when the purge gas is supplied by using the flow measuring device, wherein a tightness of the lock is assumed when the measured flow rate drops to zero, when the purge gas is supplied.