JPS6039108A - Method and device for influencing operation of blast furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for influencing the operation of a blast furnace with an annular lining for a ventilation branch and a lining for injecting hot air and fuel at the level of the hearth. The invention further relates to a device for carrying out this method.

It is known that the combustion reduction process in blast furnaces, especially blast furnaces, is sustained by hot air and solid or liquid fuel injected into the hearth through a series of steps. Due to certain imbalances in the melting zone of the furnace, the hot air cannot be evenly distributed over the contained siding. This imbalance in the melting zone is caused by uncontrolled material dumping, which causes different pressure applications on the container slats, thus causing variations in the delivery of hot air from one siding to another. cause. This means that the hot air delivery from one siding will differ from the hot air delivery from another siding by 20 to 100%. Since the fuel is combusted with the oxygen of the hot air, the injection speed of the fuel must be adapted to the hot air delivery of each part.

(5) An object of the present invention is to provide a new method that allows sufficient control of the operation of a furnace, and an apparatus for implementing this method.

To achieve this objective, the method of the invention is characterized in that the hot air delivery through each ventilation branch is measured continuously, and that the hot air delivery of the siding with a high rate of feed is carried out within the bends of each siding. by narrowing the passageway by means of a moving plug.

The invention also relates to a furnace comprising a ventilation branch consisting of a generally vertical tube and a bend in the tube connected to a nozzle located generally horizontally in the extension of the siding leading into the hearth. characterized by a plug with a frusto-conical top attached to the end of the bushing that traverses the inspection cup, the plug sliding axially therein and connected to an external device that causes the bushing to reciprocate; An apparatus for carrying out the method of the invention is provided.

By measuring the feed in each of the ventilation branch pipes,
You can decide where the hot wind will enter more intensely or where (6) will be the edict or shikonaru. Therefore, by reducing the high airflow rate, excessively hot air tends to move towards the windings with the lower airflow rate.

In other words, the less active points are stimulated to even out the work of the furnace, allowing it to function under optimal conditions.

To avoid excessive pressure, the internal channel has a widened section around the plug such that the cross section of the annular opening around the plug is larger than the annular cross section of the channel across the ventilation branch in the open position. It is preferable to have the following.

The walls of the bushing are preferably hollow throughout their entire length and are connected to a cooling circuit outside the ventilation branch.

The cover, through which the bushing passes, likewise consists of a hollow chamber connected to the cooling circuit.

The bushing passes through the cover (7) through the housing preceded by a chamber which receives a small jet of cold air coming from a mixing chamber which serves to add cold air to the hot air in order to stabilize the temperature of the hot air.

Further features of the invention will become apparent from the following detailed description of a preferred embodiment, given by way of example, with reference to the accompanying drawings, in which: FIG.

FIG. 1 shows the lower part of the blast branch consisting primarily of a vertical or generally oblique pipe 12 connected via a bend 10 to a generally horizontal part consisting of a nozzle 14 articulated with an injection tuyere 16. show.

The tuyere 16 is held securely in a tymp 18 which is attached to the outer casing 20 of the furnace (not shown). The blast branch is traversed by an internal channel 22 delimited by a refractory lining 24 . This slightly tapered channel 22 directs hot air from an annular tube (not shown) to each of the tuyeres 16. The bend 10 is suitably provided with an axial hole 26 in the extension of the shafts of the nozzle 14 and the tuyere 16, and a cover 28 that is detachable on the side opposite the tuyere 16.
is closed by. This cover 28 is usually provided with a peephole, which allows the bend 10. Nozzle 1
4 and the tuyere 16 to allow inspection of the inside of the furnace.

The present invention provides a restriction plug at the intersection between the descending and horizontal portions of channel 22. The plug 30, made of high temperature and wear resistant molded refractory material, has a cylindrical portion corresponding to the shape of the hole 26 in the bend 10 and a frusto-conical front portion that accommodates the corresponding taper of the refractory portion of the bend 10. It becomes more.

It is attached to the inner end of a bushing 32 which crosses the cover 28 and interacts externally with a drive represented by a stirrup 34. This stirrup 34 is connected to the plug 30 between the closed position shown by the solid line and the open position shown by the dashed line.
It serves to move vertically. The bushing 32 is tubular in shape and arranged coaxially with respect to the axis 0 of the nozzle I4 and the tuyere 16, so that the hearth can always be inspected in front of the tuyere 16 via the sight hole 36. The walls of the tubular bushing 32 are double-walled, or preferably triple-walled, as shown in FIG. The cover 28 through which the bushing 32 traverses the housing 42 likewise encircles the annular cooling chamber 4 connected to the cooling circuit indicated by the arrow 44.
Consists of 0.

The system is sealed to the outside by a packing box in the outer tube 48 that is welded to the cover 28.

The housing 42, which serves as a guide device for the bushing 32, does not perform such a sealing function, but merely serves to suppress impurities and hot air. When this function is to suppress impurities and hot air, the housing is indicated by an arrow 52,
This is aided by the injection of a small amount of cold air in the opposite direction, which is influenced by a chamber 50 beyond the housing 42. This small amount of air is preferably drawn into a mixing chamber (not shown) where the hot air is supplemented with the amount of cold air necessary to stabilize its temperature at a certain predetermined level. This provides the additional advantage that no compression is required to inject the hot air into the housing 42 in the opposite direction (10).

This is because the pressure drop of this small amount of air to chamber 50 is much lower than the pressure drop experienced by the hot air between the mixing chamber and bend 10.

To ensure that the housing 42 does not get stuck during sliding movement of the bushing 32 due to dust accumulation on the bushing 32 in the bend 10, a scraper 54 is placed around the bushing 32 in the cover 28, preferably as well. It is preferred to provide a so-called "floating" flapper with a flexible tongue. To avoid the need to disassemble the entire device, a plug (r shown) is installed on the underside of the scraper 54.
It is advantageous to provide a means for discharging impurities accumulated here in the direction indicated by arrow 58.

The connection between the bushing 32 and the control stirrup 34 is preferably made as shown in FIG. 1 by means of two cutouts in the bushing.

This not only facilitates the release of the control stirrup 34, but also allows the bushing and tube 2B to be easily removed if the bushing 32 is free of any shocks (11).

Figures 2-4 show three different positions occupied by the throttle plug 30. In the advanced position of FIG. 2, the passage between the lowered and horizontal portions of the channel 22 is substantially completely closed. As can be seen in FIG. 2, the cylindrical portion of the plug 30 occupies the entire cross section of the descending portion of the channel 22;
Therefore, the length is sufficient to reduce radiation of hot air toward the cover 28.

FIG. 3 shows intermediate positions corresponding to greater or lesser reductions in the delivery of hot air through channel 22, and when plug 50 assumes the position of FIG. You can receive the shipment.

It will be noted that the channel 22 has a widened portion 56 at the break between its descending and horizontal portions at the level of the plug 30.

Since this wide section 56 is such that the cross-section of the passage utilized in the position occupied by the plug 4 in FIG. 1B4 is at least equal to the cross-section of the descending portion of the channel 22, the plug 30 is No pressure drop occurs at the position shown.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram, partly in vertical section, of the lower part of the ventilation duct provided with the device of the invention; FIGS. 2, 3 and 4 are vertical sections of the bend, in the closed position assumed by the throttle plug , intermediate position, and open position, respectively. In addition, in the figure, reference numeral 10 is a pipe bend, 14 is a nozzle, 16 is a tuyere, 22 is an internal channel, 2B is an inspection cover, 30 is a plug, 32 is a bushing, 34 is a stirrup, 38 is a cooling pipe, 42 is a housing, 44 is a cooling circuit,
50 is a chamber, and 54 is a scraper. Patent Applicant Ball Worth Société Anonymous

Claims (1)

[Claims] 1. In a method for influencing the operation of a blast furnace with an annular lining for the draft branch pipes and tuyeres for injecting hot air and fuel at the level of the hearth, through each draft branch pipe. characterized in that the hot air delivery is continuously measured, such that the hot air delivery of the ventilation branches with a high rate of supply is reduced by narrowing the passage by a plug sliding into the bend of each ventilation branch. Method. 2. A draft pipe lining, each draft pipe comprising a substantially vertical pipe and a bend in the pipe connected to a nozzle arranged substantially horizontally in the extension of the tuyere leading into the hearth. In an apparatus for carrying out the method according to item 1,
2) Attached to the end of the tubular bushing 32 connected to an external device 34 that slides in the bend 10 relative to the nozzle 14 and tuyere 16 and causes the tubular bushing to reciprocate across the inspection cover 28. A device characterized by a plug 30 having a truncated conical top. 3. that the internal channel comprises a widened section around the plug 30 such that the cross section 56 of the annular opening around the plug 30 is larger in the open position than the annular cross section of the channel 22 across the ventilation branch; Apparatus according to claim 2, characterized in: 4. The device according to any one of claims 2 and 3, characterized in that the wall of the bushing 32 has a cooling circuit connected to a cooling pipe 38 over its entire length up to the front end of the plug 30. 5. The apparatus according to any one of claims 2 to 4, wherein the inspection cover 28 through which the bushing 32 passes comprises a hollow chamber 40 connected to a cooling circuit 44. 6. It is provided on the inspection cover 28 surrounding the bushing, and is preceded externally by a chamber 50 that receives a jet of cold air 52 (3) generated from a mixing chamber that serves to add cold air to the hot air in order to stabilize the temperature of the hot air. 6. A device according to any one of claims 2 to 5, characterized by a housing 42. 7. The apparatus according to claims 2 to 6, characterized by a scraper 54 provided on the inner surface of the inspection cover 28 surrounding the bushing 32. 8. The apparatus of claim 9, wherein the bushing is hollow and the longitudinal axis of the bushing is aligned with the peephole. 9. The apparatus according to claim 7, characterized in that the scraper 54 includes a discharge plug provided on the lower side. 10. Claim 2, characterized in that the device for displacing the bushings consists of stirrups 34 that slide within two parallel notches provided in the bushings 32.
The apparatus according to items 9 to 9.