AU2015357769B2

AU2015357769B2 - Closure system with a conical closure

Info

Publication number: AU2015357769B2
Application number: AU2015357769A
Authority: AU
Inventors: Ganesh Arumugam; Volker Deisinger; Frederic Judas; Michael Kress; Osman Turna
Original assignee: Nalwa Special Steel Raigarh Ltd
Current assignee: Nalwa Special Steel Raigarh Ltd
Priority date: 2014-12-03
Filing date: 2015-11-24
Publication date: 2021-04-01
Anticipated expiration: 2035-11-24
Also published as: WO2016087049A1; DE102014117788A1; CN105664797A; AU2015357769A1; CN205392353U

Abstract

A closure system for a container or reactor to be charged with bulk material and kept under excess pressure in the closed condition, comprising a conical closure with a seat with a circular opening and a conical or frustoconical closing body, wherein the seat and the closing body are formed such that in the closed condition of the conical closure they form a single circular point of contact, wherein the closure system furthermore comprises a gas distribution system which is formed such that on the pressure side it is able to circumferentially blanket the point of contact which in the closed condition of the closure is formed by seat and closing body.

Description

CLOSURE SYSTEM WITH A CONICAL CLOSURE

TECHNICAL FIELD The invention relates to a closure system for a container or reactor to be charged with bulk material and kept under excess pressure in the closed condition, comprising a conical closure with a seat with a circular opening and a conical or frustoconical closing body, wherein the seat and the closing body are formed such that in the closed condition of the conical closure they form a single circular point of contact. The invention furthermore relates to the use of such closure system at the inlet and/or outlet of the charging lock of a fixed-bed pressure gasification reactor and a method for lowering the process gas fraction in the leakage gas stream exiting from a conical closure.

BACKGROUND Such closure systems are known. The document DE 40 41 445 Al shows the basic construction of a closure system frequently used for fixed-bed pressure gasification reactors. It 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 point of contact 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 point of contact with the lumpy material or with dust-like material abraded from the same. It frequently occurs that rests of the lumpy material or foreign bodies present in the lumpy material are deposited there and thus prevent tight closing.

The patent specification DE 32 29 841 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, elastic material which is installed on the pressure side, concentrically with the metallic main seal.

However, this system neither can ensure with certainty that the sealing surface remains free of solid residues. It must rather be assumed that in many cases solid residues remain on the sealing surface and prevent complete closing of the conical closure. Soft seals, too, do not securely eliminate the problem, as they are very sensitive to wear and can be exchanged only with great expenditure and by accepting an interruption of the production. For these reasons, it cannot be excluded that in the harsh operating practice soft seals only are exchanged after they have been untight for some time already.

It therefore is the object of the invention to provide a sealing system for a container closure which prevents or at least greatly decreases the exit of process gases which in many cases are harmful to health and explosible, even when the container closure is not closed completely for the above reasons.

SUMMARY

According to a first aspect, there is provided a closure system for a container or reactor to be charged with bulk material and kept under excess pressure in the closed condition, comprising a conical closure with a seat with a circular opening and a conical or frustoconical closing body, wherein the seat is equipped with a seal, and the seal and the closing body are formed such that in the closed condition of the conical closure they form a single circular point of contact, wherein the closure system furthermore comprises a gas distribution system which is formed such that on the pressure side it is able to circumferentially blanket the point of contact which in the closed condition of the closure is formed by seat and closing body, gas from the gas distribution system, before reaching the point of contact, does not flow through the seal, and the gas distribution system comprises channels for the passage of gas, which extend completely in the seat of the closure.

The closure system according to the invention is formed such that its gas distribution system is able to blow a constant slight stream of a harmless gas, e.g. nitrogen or carbon dioxide, on the pressure side, i.e. from the inside of the reactor or container, against the point of contact of seat and closing body. Such purging or blowing with a harmless gas is referred to as blanketing. It is important that the closure system is formed such that the outflow of the blanketing gas into the interior space of the reactor or container is not blocked. Without this outflow possibility, a pressure would build up below the point of contact of seat and closing body, which from time to time is released to the outside or into the interior space in an uncontrolled way. This could only be prevented by an expensive system for controlling the pressure in this gas distribution system. Therefore, it is very much less expensive and also more reliable, unless the quality of the product gas present in the reactor or container is impaired thereby to an inadmissible extent, to permit the outflow of the blanketing gas into the interior of the reactor.

This arrangement is very robust and resistant to high operating temperatures, dust and corrosive process gases.

In one form, the gas distribution system comprises tubes for the passage of gas, which extend below the seat of the closure. This arrangement has the advantage that it can be retrofitted at low cost and can be exchanged when it is worn.

In one form, neither the seat nor the closing body is equipped with a deformable seal. This arrangement has the advantage that frequent downtimes for the exchange of the deformable seals susceptible to wear are avoided.

In one form, the deformable seal is a soft seal.

The closure system according to the invention in particular is suitable for use at the inlet and/or outlet of the charging lock of a fixed-bed pressure gasification reactor for the production of a product gas comprising hydrogen and carbon oxides from carbonaceous fuel. As fuel for these reactors coal or coke is used in many cases. These substances tend to prevent complete closing of the closure due to dust deposits and small particles on the sealing surface. Furthermore, the product gases generated in these reactors, such as carbon monoxide and hydrogen, are very harmful to health and explosible, so that their leakage from the closure definitely must be inhibited.

In a further aspect, there is provided a method for lowering the process gas fraction in the leakage gas stream exiting from a conical closure of a closure system, , which employs a closure system as described above, comprising the following steps: - Charging the container or reactor with fuel is stopped, - the gas supply to the gas distribution system of the closure system is opened, so that gas flows out of the ring nozzle, - the closing body is pressed into the seat, wherein during the approach of the closing body to the ring nozzle the closing body in part is liberated from deposits and for blowing off deposits the gas quantity can briefly be increased (gas surge), - the gas supply is throttled to a quantity harmless for the gas production in the reactor, the remaining gas quantity blankets the point of contact (sealing surface) of closing body and seat,

- closing of the gas supply to the distribution system and opening of the closure for newly charging the container or reactor with fuel.

BRIEF DESCRIPTION OF DRAWINGS 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.

Fig. 1 shows an exemplary design of a closure system according to the invention.

DESCRIPTION OF EMBODIMENTS In this example, the closure system 1 separates a container or reactor space 2 under excess pressure from the bulk material collector space 3 under atmospheric pressure. The closure system 1 substantially consists of the closure seat 4, the closure body 5 and the blanketing system. The closure seat 4 is equipped with the seal 6. For opening the closure, the closure body 5 is lowered by a non-illustrated mechanism and for closing it is moved upwards and pressed against the seat 4 and the seal 6, respectively. In this example, the blanketing system is integrated into the closure seat 4. It substantially consists of a gas supply line 7, a ring channel 8 and a ring-shaped cover plate 9. The drawing shows the closure body 5 in a position shortly before or after leaving the closed position, i.e. there is a gap between closure body 5 and seal 6. On closing of the closure, a gas surge in this position can be passed into the gap between closure body 5 and seat 4 via the blanketing system, in order to at least partly remove deposits of the bulk material (not shown). After closing of the closure, the blanketing system on the pressure side puts a gas curtain before the point of contact between closure body 5 and seal 6 by supplying a constant gas stream to the ring channel 8 through line 7. It is accepted here that at least a part of the blanketing gas flows off through the gap between the closure body 5 and the cover plate 9 into the container or reactor space 2. When tight closing of the closure is prevented by deposits, blanketing gas primarily escapes as leakage gas by largely retaining the process gas present in space 2.

Throughout the specification and the claims that follow, unless the context requires otherwise, the words "comprise" and "include" and variations such as "comprising" and "including" will be understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement of any form of suggestion that such prior art forms part of the common general knowledge.

It will be appreciated by those skilled in the art that the invention is not restricted in its use to the particular application described. Neither is the present invention restricted in its preferred embodiment with regard to the particular elements and/or features described or depicted herein. It will be appreciated that the invention is not limited to the embodiment or embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the scope of the invention as set forth and defined by the following claims.

Industrial Applicability The invention provides an inexpensive solution for the reduction of the quantity of outflowing gases harmful to the environment. Downtimes due to a closure not closed completely are avoided therewith in many cases. The invention hence is really useful and therefore is industrially applicable.

List of Reference Numerals

1 closure system 2 container or reactor space 3 bulk material collector space 4 closure seat 5 closure body 6 seal 7 gas supply line for blanketing gas 8 ring channel 9 cover plate

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A closure system for a container or reactor to be charged with bulk material and kept under excess pressure in the closed condition, comprising a conical closure with a seat with a circular opening and a conical or frustoconical closing body, wherein the seat is equipped with a seal, and the seal and the closing body are formed such that in the closed condition of the conical closure they form a single circular point of contact, wherein the closure system furthermore comprises a gas distribution system which is formed such that on the pressure side it is able to circumferentially blanket the point of contact which in the closed condition of the closure is formed by seat and closing body, gas from the gas distribution system, before reaching the point of contact, does not flow through the seal, and the gas distribution system comprises channels for the passage of gas, which extend in the seat of the closure.

2. The closure system according to claim 1, wherein the gas distribution system comprises tubes for the passage of gas, which extend below the seat of the closure.

3. The closure system according to any of the preceding claims, wherein neither the seat nor the closing body is equipped with a deformable seal.

4. The closure system according to claim 3, wherein the deformable seal is a soft seal.

5. Use of the closure system according to any of the preceding claims at the inlet and/or outlet of the charging lock of a fixed-bed pressure gasification reactor for the production of a product gas comprising hydrogen and carbon oxides from carbonaceous fuel.

6. A method for lowering the process gas fraction in the leakage gas stream exiting from a conical closure of a closure system, wherein the closure system is a closure system according to any of claims 1 to 4, and the point of contact formed by the seat and closing body is blanketed with a sealing gas.