FR2554664A1 - REACTOR SEAL - Google Patents

Abstract

THE INVENTION CONCERNS A DEVICE FOR ACHIEVING THE SEALING OF A REACTOR DURING THE CONNECTION OF A GENERATOR DURING THE CONNECTION OF A PLASMA GENERATOR. THE DEVICE IS CONSTITUTED BY AN ANNULAR SEAL 13 MOUNTED ON A SEAT 12, THE ANNULAR SEAL BEING PROVIDED WITH ORIFICATIONS 18 FOR THE INTRODUCTION OF A PROTECTIVE GAS.

Description

REACTOR SEAL

  The invention relates to a device for sealing a reactor.

  during connection of a burner to a shaft furnace, preferably

  during the connection of a plasma generator to a nozzle in a cell furnace, for example an oven for the

reduction of metal oxides.

  Swedish patent application no. 83 04 722-5 describes a process

  dice and a device for replacing a plasma generator during the continuous operation of a reactor of a shaft furnace. This is achieved by means of a valve placed in the wall of the reactor in conjunction with the nozzle of the reactor, the

  valve completely isolating the reactor from the surrounding atmosphere

  humming when the plasma generator is removed; it is possible to open the valve only when the plasma generator is in its closed position, i.e. with its nose partially inserted in the connection part of the

reactor nozzle.

  The disadvantage of the process described above is that during

  the interval between the opening of the valve and the

  placing the plasma generator from its closed position to its working position, there is a leak through the slot between the wall of the reactor nozzle and the nose of the plasma generator. This leakage can be reduced to a minimum by providing that the orifice in the connection part of the nozzle, is made so as to fit tightly on the nose of the plasma generator. This somewhat reduces the leak. However, manufacturing becomes more expensive, and the insertion of the plasma generator more complicated. The objective of the invention is to propose a sealing or jointing device which completely eliminates the leak appearing during the insertion of a burner into a reactor in operation, in particular during the insertion of a plasma generator from its closing position, when a valve is opened which normally completely protects the reactor from the surrounding atmosphere, until the plasma generator is inserted in its working position where it is

  pressed against the sealing surface of the reactor.

  To this end, the invention provides a seal device characterized by an annular seal mounted on a seat at the connection part with the nozzle of the reactor, the ring being provided with orifices distributed over its circumference to allow a connection with a source of protective gas. By using a protective gas at practically the same pressure, or at a pressure higher than that prevailing in the reactor, it is ensured that gas cannot escape from the reactor and also that a large clearance can be expected.

  around the connection part of the reactor nozzle.

  This considerably facilitates and accelerates insertion.

  Other characteristics and advantages of the invention will

  appear using the detailed description below and

  opposite the accompanying drawings, in which the figures

  have: - Figure 1: a partially sectional view of the

  connection part of a reactor nozzle with a generator

  plasma rator inserted in its working position, and - Figure 2: an enlarged view of the seal device according to the invention. FIG. 1 represents a plasma generator 1 with its nose 2 inserted in the operating position in the connection part 3 of the nozzle 4 of a reactor, placed in the

  wall of a shaft furnace, not shown in detail. The general-

  The plasma generator is inserted in a closed position where the disc 6 of the valve 5 opens, after which the generator is inserted in the operating position shown in the figure. A front surface 7 of the plasma generator thus comes against the sealing surface 8 on the portion of the connection part facing outwards. A certain form of joint is preferably also arranged

between the two surfaces.

  The seal device according to the invention shown on an enlarged scale in Figure 2, is constituted by a

  flange 9 with a channel 10 for the supply of pro gas

  tection. In the flange 9 is a seat 12 for an inner annular seal 13. The annular seal 13 is held in place by a locking ring 14, fixed by bolts, represented by dashes 15. FIG. 2 also shows an O-ring 16 ensuring the seal between the generator

  of plasma and the sealing surface.

  The annular seal 13 is provided with a groove 17 facing inward with orifices 18 communicating with an annular space 19 outside the annular seal 13. Dup shielding gas is introduced into the space 19 through the channel

mentioned above..

  The design according to the invention makes it possible to provide a large clearance between the connection part 3 of the nozzle and the plasma generator, since the annular seal 13 properly

  said can have a diameter practically equal to the circumference-

  nose of the plasma generator. The annular seal 13 can be made of metal (hematite) to prevent it from being damaged by soot and deposits of waste on the

  generator nose when removed.

  According to the preferred embodiment of the invention, the annular seal 13 is made of a material which is at least partially elastic and has a low coefficient of

  friction, for example Teflon. By conferring on the joint annu-

  With an enlarged conical inlet end 20, the connection of the plasma generator is further facilitated. Examples of suitable shielding gases are nitrogen and argon. The seal device according to the invention thus eliminates any

  possibility of leakage from the reactor during construction

  tion of the connection to the generator. Rather, shielding gas will flow and, to some extent, will enter the reactor. However, the flow entering the reactor can be minimized by careful adjustment of the pressure of the shielding gas so that it

  only slightly exceeds the pressure in the reactor.

Claims (1)

CLAIMS 1 Device intended to seal a reactor during the connection of a burner to a reactor nozzle, and preferably, during the connection of a plasma generator to a reactor nozzle in a single-chamber furnace for the reduction of metal oxides, device characterized by an annular seal (13) mounted on a seat (12) at the connection part (3) of the reactor nozzle, the annular seal having orifices (18) for the introduction of shielding gases. 2. Device according to claim 1, characterized in that the annular seal (13) is provided with an enlarged, conical inlet part (20). 3. Device according to one of claims 1 or 2, characterized in that the annular seal (13) fits tightly on the part (2) of the plasma generator which must be inserted. 4. Device according to any one of claims 1 to 3, characterized in that a groove (17) with orifices (18) for the introduction of protective gas is provided on the surface facing the inside of the annular seal (13). 5. Device according to any one of claims 1 to 4, characterized in that the seat (12) of the annular seal (13) comprises an annular flange (14) fixed by, bolts (15). 6. Device according to any one of claims 1 to 5, characterized in that the annular seal (13) is made of hematite. 7. Device according to any one of the claims   1 to 5, characterized in that the annular seal (13) is made of Teflon.