Patent Application
20110285066
This invention relates generally to blast furnace iron making operations and more particularly to a plug for use on a tap drill.
Raw materials, including iron ore, limestone, and coke are added to a blast furnace 140 where they are heated (
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 (
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.
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.
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.
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
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.
