US 4,378,993 A · Method and apparatus for measuring height level of melting zone in blast furnace

Abstract

A desired number of cables are drawn, along with the falling charge, into a blast furnace from its top and the forward ends of the cables are melted upon reaching the melting zone in the furnace. The length of each of the cables to its melted end is measured in accordance with the result of a voltage pulse response measurement utilizing the distributed constant circuit characteristics of the cable, and the height level of the melting zone inside the furnace is measured from the cable length by correcting it for the amount of deflection of the cable within the furnace. By measuring the cable length at each of a plurality of radial locations of the furnace, it is possible to estimate the three-dimensional shape of the upper boundary of the melting zone with a high degree of accuracy.

Claims8

Dependent claims

A method of measuring the height level of the top of a melting zone of a charge within a blast furnace, said method comprising the steps of:

Inserting and lowering at least one coaxial or multi-core cable having an electrically opened forward end into said furnace from the top thereof in such a manner that the forward end of said cable reaching the top of said melting zone is melted and said cable is drawn downward continuously along with a charge falling within said furnace;
applying at predetermined intervals a sharp step voltage to said cable from the furnace top side thereof toward said forward end;
and
measuring a response of a reflected wave from said forward end caused by said step voltage,
whereby measuring variation in the length of said cable due to the melting of said cable forward end reaching the top of said melting zone in accordance with the time response of said reflected wave by said step voltage and determining from the result of said measurement the height level of the top of said melting zone.

2 more elements

An apparatus for measuring the height level of the top of a melting zone of a charge within a blast furnace, said apparatus comprising:

at least one coaxial or multi-core cable including conductors made from materials having melting points close to that of substance in the charge in said furnace which is to be melted, said cable having its forward end opened electrically;
means for inserting and lowering said cable into said furnace from the top thereof at a selected radial location of said furnace;
feed measuring means for measuring the length of feed of said cable drawn downward in said furnace along with the falling of said charge;
cable feed speed measuring means for computing a momentary feed speed of said cable from the feed length thereof;
voltage pulse supply means for applying at predetermined time intervals a sharp step voltage to said cable at the furnace top side thereof;
reflected wave reading means for detecting a time response of a reflected wave produced by said step voltage;
means for measuring the falling speed of said charge within said furnace;
and
means for computing the length of said cable to said cable forward end in accordance with the response time of said reflected wave produced by said step voltage and correcting said measured cable length in accordance with said measured values of cable feed length, cable feed speed and falling speed of charge within furnace to thereby measure the length of melting loss and the height level of the melted forward end of said cable at said predetermined intervals.

6 more elements

Dependencies are inferred from the claim text.

Method and apparatus for measuring height level of melting zone in blast furnace

Life of this patent

Method and apparatus for measuring height level of melting zone in blast furnace

Life of this patent

Abstract

Claims8