BLAST FURNACE PLUG

Abstract

An apparatus for centering a tap drill is provided herein. The device includes a body made of a refractory material that has a tapered shape and a connector secured to body configured to permit connection of the body to a tap drill bit. In addition, a method of operating a blast furnace is provided herein. The method includes providing a blast furnace plug having a refractory body having a tapered configuration. Securing the blast furnace plug to a tap drill bit. Aligning the blast furnace plug with a tap hole plugged with mud, and inserting the blast furnace plug into the mud to create an indentation in the mud having a tapered configuration. Removing the blast furnace plug from the tap drill bit, aligning the tap drill bit with the indentation and tapping the blast furnace.

Description

This invention relates generally to blast furnace iron making operations and more particularly to a plug for use on a tap drill.

BACKGROUND

Raw materials, including iron ore, limestone, and coke are added to a blast furnace 140 where they are heated (FIG. 1). As the raw materials are heated, molten iron 160 forms at the bottom of the blast furnace 140 and a layer of slag 150 forms on top of the molten iron 160. After a sufficient volume of molten iron 160 builds up at the bottom of the blast furnace 140, the blast furnace 140 is tapped to remove the molten iron 160. A tap drill 110 having a drill bit 115 is used to tap the blast furnace 140 by drilling out the tap hole 130. As the tap drill 110 and drill bit 115 is removed, molten iron 160 flows through the tap hole 130 into a trough 120 where it is routed to a waiting rail car (not shown).

When all of the molten iron 160 is drained out of the blast furnace 140, or after a desired amount of iron 160 has been drained from the blast furnace 140, the tap hole 130 is sealed (FIG. 2). The tap hole 130 is sealed with a mud gun 210. An anhydrous mixture, commonly referred to as “mud” or “clay” is loaded into the mud gun 210. The mud gun 210 rotates from a non-operating or resting position to its operating position (as shown). In its operating position the mud gun 210 is positioned so that the nozzle 215 of the mud gun 210 is aligned with the tap hole 130. Mud 170 is extruded through the nozzle 110 and forced into the tap hole 130. The mud 170 forces the residual molten iron 160 and slag 150 that is in the tap hole 130 back inside the furnace 140. Inevitably, however, not all of the iron 160 and slag 150 is pushed back into the furnace 140 i.e., some of the iron 160 or slag 150 remains in the tap hole 130 and mixes with the mud 170 forming a mud and ore residue 180. The mud gun nozzle 110 remains in place until the mud 170 begins to dry or cure, and is rotated back away from the blast furnace 140.

Occasionally, the blast furnace 140 experiences a break out. A break out occurs when the tap hole 130 is not sealed properly and the iron 160 unexpectedly breaks through the mud 170 and stars flowing out of the blast furnace 140. An unexpected breakout is dangerous and may result in injury, damage, and loss of productivity. In addition, if the breakout is not rapidly contained, significant clean up labor is required. In the past, a wooden plug has been hammered onto the drill bit 170 and an operator attempts to swing the wooden plug into the tap hole to stop or stem the flow of iron 160 into trough 120 until the mud gun 110 is loaded with mud 170 and ready to swing into place.

When a sufficient volume of molten iron 160 builds up in the blast furnace 140 the process may be repeated. Ideally, the tap drill 110 and drill bit 115 are rotated into place and drill a clean hole through the center of the tap hole 130. Often the tap drill bit 170 walks or moves around before it penetrates very far into the tap hole 130 resulting in an irregular shaped, or oversized hole. This is undesirable because the size of the drilled hole controls the speed of the flow of molten iron 160 out of the blast furnace 140.

SUMMARY

An apparatus for centering a tap drill is provided herein. The device includes a body made of a refractory material that has a tapered shape and a connector secured to body configured to permit connection of the body to a tap drill bit. In addition, a method of operating a blast furnace is provided herein. The method includes providing a blast furnace plug having a refractory body having a tapered configuration. Securing the blast furnace plug to a tap drill bit. Aligning the blast furnace plug with a tap hole plugged with mud, and inserting the blast furnace plug into the mud to create an indentation in the mud having a tapered configuration. Removing the blast furnace plug from the tap drill bit, aligning the tap drill bit with the indentation and tapping the blast furnace.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 (Prior Art) is a cross-section of a blast furnace, a tap hole, a tap drill and a trough;

FIG. 2 (Prior Art) is a cross-section of a blast furnace, a tap hole, a mud gun nozzle and a trough;

FIG. 3 is an embodiment of a blast furnace plug;

FIG. 4 is a cross sectional view of a blast a furnace, blast furnace plug attached to a tap drill used in accordance with one embodiment, a tap hole and a trough; and

FIG. 5 is also a cross sectional view of a blast furnace, and blast furnace plug attached to a tap drill used in accordance with another embodiment, a tap hole and a trough.

DETAILED DESCRIPTION

FIG. 3 illustrates an embodiment of a blast furnace plug 300. In one embodiment, the blast furnace plug 300 has a conical body 310, which is preferably made of a refractory material, and more preferably, a 3100° to 3400° refractory material. Blast furnace plug 300 may also include rebar 320 to increase the strength and durability of the blast furnace plug 300. Blast furnace plug 300 includes a connector or drill head 330. Drill head 330 is sized to fit over drill bit 115, so that blast furnace plug 300 may be secured to tap drill 110 without having to remove drill bit 115 (FIG. 1).

Blast furnace plug 300 has tapered body, more specifically, the body of the illustrated embodiment has a frusto-conical shape. Other shapes, such as conical, or conical with a rounded end are contemplated and within the scope of the present invention.

Blast furnace plug 300 has two primary functions. The first function is to ensure that the tap drill 110 and drill bit 115 are centered in the tap hole 130 when the blast furnace 140 is tapped. FIG. 4 illustrates one method of ensuring that tap drill bit 115 is centered when drilling a tap hole. Blast furnace plug 300 to the end of tap drill bit 115 by sliding drill head 330 over the drill bit 115. When the mud gun 210 is moved away from tap hole 130, tap drill 110, drill bit 125 and blast furnace plug 300 may be swung over trough 120 and lined up with the center of tap hole 130. Blast furnace plug 300 may be forced into tap hole 130 creating an indented portion at the center of tap hole 130. This operation may be completed at any time, however, it is preferable to conduct this operation immediately after removing the mud gun nozzle 215 from the tap hole 130. The indentation (not shown) caused by blast furnace plug 300 is round and tapers toward the center of tap hole 130.

The indentation preserves the integrity of the tap hole. During the tapping operation, blast furnace plug 300 is removed from the end of drill bit 115 and the tap drill 110 is moved into position. Drill bit 115 is inserted into the indentation caused by blast furnace plug 300. The indentation causes the drill bit 115 to be centered on the tap and prevents the drill bit 115 from walking during the tapping operation. Accordingly, the resulting drilled tap hole has uniform opening and a uniform bore, which serves maintain the integrity of the tap hole 130 and aids in controlling the speed and flow of the iron 160 is more controlled.

In addition, the blast furnace plug 300 may be used as a safety plug as illustrated in FIG. 5. During normal operation, blast furnace plug 300 is connected to tap drill bit 115 after the taping operation or while the tap hole is being plugged with the mud gun 210 so that the blast furnace plug 300 may be used to create the centering indentation after the mud gun 210 operation is complete. The blast furnace plug 300 is preferably left attached to the tap drill 210. In the event of an unexpected break out 500, the tap drill 210 with the blast furnace plug 300 attached thereto may immediately be swung into position and the blast furnace plug 300 forced into the tap hole 130 to plug the tap hole 130 until the break out 500 is stopped or the mud gun 210 is refilled and ready to re-plug the tap hole 130.

While the present invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. For example the shape of the blast furnace plug 300 may have a rounded end, or a pointed end. Therefore, the invention, in its broader aspects, is not limited to the specific details, the representative apparatus, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant's general inventive concept.

Claims

1. A device for centering a tap drill comprising:

a body made of a refractory material;

the body having a tapered configuration; and

a connector secured to body configured to permit the connection of the body to a tap drill bit.

2. The device of claim 1 wherein the tapered body has a conical shape.

3. The device of claim 2 wherein the tapered body has a frusto-conical shape.

4. The device of claim 2 further comprising one or more pieces of reinforcement material located within the conical body.

5. The device of claim 2 wherein the refractory material is a 3100° to 3400° refractory material.

6. The device of claim 2 wherein the refractory tapered body has a rounded end.

7. The device of claim 2 wherein the refractory tapered body has a pointed end.

8. An apparatus for a blast furnace comprising:

a tapered body comprising a refractory material;

at least one reinforcing member within the tapered body; and

a drill head secured to the tapered body for connecting the tapered body to a tap drill bit.

9. The device of claim 8 wherein the tapered body has a conical shape.

10. The device of claim 9 wherein the tapered body has a frusto-conical shape.

11. The device of claim 8 wherein the refractory material is a 3100° to 3400° refractory material.

12. A method of operating a blast furnace comprising:

providing a blast furnace plug having a refractory body having a tapered configuration;

securing the blast furnace plug to a tap drill bit;

aligning the blast furnace plug with a tap hole plugged with mud;

inserting the blast furnace plug into the mud;

creating an indentation in the mud having a tapered configuration;

removing the blast furnace plug from the tap drill bit;

aligning the tap drill bit with the indentation; and

tapping the blast furnace.

13. The method of operating a blast furnace of claim 12 wherein the tapered configuration is a frusto-conical configuration.

14. The method of operating a blast furnace of claim 12 wherein refractory material is a 3100° to 3400° refractory material.

15. The method of operating a blast furnace of claim 12 wherein the tapered configuration includes a rounded end.

16. The method of operating a blast furnace of claim 12 wherein the tapered configuration includes a pointed end.

17. A method of stopping a breakout of molten iron from a blast furnace:

providing a blast furnace plug comprising a tapered body made of refractory material and a connector secured to the body for connecting the blast furnace plug to the end of a tap drill bit;

securing the blast furnace plug to a tap drill bit;

aligning the blast furnace plug with a tap hole during a breakout; and

inserting the blast furnace plug into the tap hole until the molten iron stops flowing out of the tap hole.