CN101547530B - Method for carrying out effectiveness judgment and processing on electrode clamping of calcium carbide furnace control system - Google Patents

Abstract

The invention discloses a method for carrying out effectiveness judgment and processing on electrode clamping of a calcium carbide furnace control system, which comprises the following steps that: current values or power values are sent to a computer according to the requirements of calcium carbide furnace smelting products and a process on voltage, current and power; a computer control system compares and computes parameter values detected in real time and set values, and sends a group of instructions to a control relay to drive electrodes to move up and down; and when furnace conditions are abnormal, the effectiveness of the electrode clamping may have greater deviation, so that the power of a three-phase electric arc has overlarge deviation, the effectiveness of the electrode clamping is judged in the moment, and the clamping is released timely. The method can perform effectiveness judgment and processing on the electrode clamping so as to solve the problem that the terminal of a three-phase electrode still can be accurately controlled in a given range when the furnace conditions are abnormal, accurately control the power balance of the three-phase electric arc, improve the electro-thermal conversion efficiency, and achieve the aims of saving electricity, increasing production and improving ore recovery ratio.

Description

The method that electrode clamping of calcium carbide furnace control system effectiveness is judged and handled

Technical field

The present invention relates to a kind of rise fall of electrodes autocontrol method, especially a kind of furnace of calcium carbide rise fall of electrodes is the method for control automatically.

Background technology

Furnace of calcium carbide belongs to a kind of of the hot stove series in ore deposit, and the product of smelting is a calcium carbide, and the core theory that it is smelted is: form directed high temperature ion flow-electric arc by ionized air, convert electric energy to heat energy, for reduction reaction provides sufficiently high temperature field.

The state of electric arc depends on the temperature around conductivity, voltage and the electrode of distance, discharge body of electrode tip and discharge body and the resistance characteristic of furnace charge medium.In smelting process, continuous rising along with furnace bottom bath surface (or top of the slag), furnace charge is regular to be stayed, the motor termination is because of moving on the scaling loss and the variation of molten bath conductivity, need to adjust the physical location of electrode in good time, arc power can be in optimum state all the time in the stove to keep, also want simultaneously to keep the arc length of three-phase electrode electric arc basic identical, discharge identical arc power to keep three-phase electrode, the reduction reaction zone that keeps identical size, the higher electrical efficiency that electric power system can be reached, one of key that reaches this purpose is exactly that the rise fall of electrodes control system is wanted and can accurately be measured calculating to the position of electrode tip, then, and could be according to the height of electrode tip position, and then adjust electrode position, the primary heat transport system of pilot arc power two efficient in good time.

Domesticly once introduced external complete large-scale furnace of calcium carbide equipment, this technology has installed displacement transducer additional for every strip electrode, is used for the concrete displacement size of surveying record electrode and position just.This specification requirement is regularly carried out zero clearing to electrode position and is handled.Because the complexity in the furnace of calcium carbide, the arc power size of every phase electrode depends on the relative distance size of electrode tip and other end discharge body, so the position that only depends on the displacement sensor electrode is the purpose that is difficult to obtain control three-phase electrode arc power balance.So domestic have a small amount of furnace of calcium carbide automatic control system that displacement transducer has been installed poor effect basically, revert to state of a control manually substantially again.

The cold conditions ore is non-conductive, and the molten state mixture is a good conductor of electricity, and these characteristics have determined the complexity and the difficult point of furnace of calcium carbide rise fall of electrodes control system, also is numerous forerunners that are engaged in ore deposit hot stove automation control the cause for the success places not yet so far.Up to the present, domestic existing rise fall of electrodes in mine hot stove is commonly control manually, when electric current during greater than setting, promote electrode, when electric current during less than setting, the decline electrode, individually the methods with PLC control also are based on the method identical with Artificial Control, its major defect is that manually-operated randomness is big, labour intensity big, three-phase power imbalance, power consumption height, yield poorly, ore recovery ratio is low.

Chinese patent ZL200610035949.0 discloses the automatically method of control of a kind of rise fall of electrodes in mine hot stove, and this method provides a kind of method that can stabilized electrodes.But, do not relate to when the working of a furnace and take place when unusual, the method for control electrode position how when the former balance of furnace of calcium carbide automatic electrode control system position must be made bigger the adjustment again.

Summary of the invention

In order to overcome the above-mentioned shortcoming of prior art, the invention provides a kind of method that can accurately control relative position between furnace of calcium carbide three-phase electrode termination and the discharge body, can control three-phase electrode arc power length and balance, reduction melting electric consumption, boost productivity and improve the furnace of calcium carbide automatic electrode control system clamp effectiveness judgement of ore recovery ratio and the method for handling.

The technical solution adopted for the present invention to solve the technical problems is: the method that a kind of electrode clamping of calcium carbide furnace control system effectiveness is judged and handled, when the computer control electrode rises or descend, if electrode is by clamp, then the three-phase arc power is carried out the balance computing, bigger than normal when certain phase electrode arc power, when exceeding License Value, remove clamp, again carry out the computing of electrode position balance, in new position three-phase electrode carried out clamp and handle:

If A electrode current variable quantity is Δ Ia, B electrode current variable quantity is Δ Ib, C electrode current variable quantity is Δ Ic, the current change quantity deviate is DELTACURRENT, if A electrode displacement variable is HHA, B electrode displacement variable is HHB, and C electrode displacement variable is HHC, the position deviation permissible value is AEDISTANCE

Computational methods:

When electrode is in clamp state, promptly

(| HHA-HHB| 〉=AEDISTANCE) or

(| HHB-HHC| 〉=AEDISTANCE) or

(| during HHA-HHC| 〉=AEDISTANCE)

If Δ Ia 〉=DELTACURRENT or Δ Ib 〉=DELTACURRENT

Or Δ Ic 〉=DELTACURRENT, then remove electrode clamping.

Good effect of the present invention is: according to the requirement to voltage, electric current and power of furnace of calcium carbide matallurgical products and technology, give computer (set point) with the numerical value form of electric current or power, computer control system automatically detected in real time parameter value (voltage, electric current) carries out carrying out three-phase equilibrium and comparison operation with set point after the A/D conversion, and carry out analysis and judgement according to mathematics of control model, control strategy and unusual working of a furnace model, send one group then and instruct to control relay.Control relay drive motors control contactor or hydraulic buttery valve, electric motor control contactor drive motors rotate (or hydraulic buttery valve driving hydraulic jack) and then drive electrode and move up and down; Simultaneously, computer also will to electrode up and down distance calculate, when the distance of any two-phase of three-phase electrode termination during greater than set-point, this electrode will be motionless by clamp; Simultaneously, deviation may appear in the effectiveness of electrode electronics clamp when the working of a furnace is unusual, can cause three-phase electric arc power deviation excessive, at this moment, must judge the effectiveness of electrode electronics clamp, and remove clamp in good time.To the weighing apparatus of three-phase electrode levelling again, carry out clamp at reposition.

The present invention can carry out effectiveness judgement and processing to electrode electronics clamp, and levelling weighing apparatus, clamp are handled again to carry out three-phase electrode.The termination of three-phase electrode accurately is controlled in the given range, reaches accurate control three-phase electric arc power-balance, improve electricity, thermal conversion efficiency, reach the purpose of economize on electricity, volume increase and raising ore recovery ratio.

Description of drawings

The present invention will illustrate by example and with reference to the mode of accompanying drawing.

Fig. 1 is a control circuit block diagram of the present invention.

Among the figure: GK-isolating switch, ZK-vacuum switch, B-transformer, L-current transformer, M-motor, LCD-display screen, J-relay.

Embodiment

As Fig. 1, a kind of method of automatically balancing electrodes of automatic control system of calcium carbide furnace, it is elementary that electrical network 110KV (35KV) three-phase alternating current inserts ore heat furnace transformer B through isolating switch GK, vacuum switch ZK, after conversion at the secondary output 80V of transformer B three-phase alternating current to 500V, join by the short net in the heavy in section of forming by heavy in section copper pipe or copper coin, soft copper cable, electric installation and graphite electrode, enter in the stove, electrical power is provided.

At the elementary or secondary current transformer L that is equipped with of transformer B, the ac current signal of output 0-5 ampere is transformed to the direct voltage analog signal of 0-5V (or 0-10V) through signal converter, offers the A/D sampling plate; Another road three-phase alternating voltage signal is directly taken from B level of the transformer outlet row, is the 0-500V ac voltage signal, is transformed to 0-5V or 0-10V direct voltage analog signal through signal converter, offers the A/D sampling plate; The A/D sampling plate is that six way word signals are for Computing with above-mentioned six road direct voltage analog signal conversion; Simultaneously, ten four road or 20 road hand control switch signals, the spacing control switch signal of Shi Erlu carry out computing by I/O input/output board access computer.

After machine was handled as calculated, output signal of the present invention transferred to motor driven systems or fluid power system respectively, that is:

For motor driven systems: the output signal of computer through I/O input/output board outbound course signal to auxiliary relay control motor contactor, thereby realize that control motor M drives the upper and lower motion of electrode lifting mechanism drive electrode, thereby change the size of electrical power in the stove; When motor M rotates, releasing of brake, when motor M stops, the brake braking;

For fluid power system: the output signal of computer outputs signal to control relay through the I/O input/output board, control relay drives solenoid movement, the upper and lower motion of hydraulic jack of control fluid power system, make the upper and lower motion of electrode by hydraulic jack drive electrode elevating mechanism, thereby change the size of electrical power in the stove.

The set point of control signal is input to the calculator memory storage by keyboard.

Design principle of the present invention is: when the computer control electrode rises or descend, if electrode is by clamp, then the three-phase arc power is carried out the balance computing, phase electrode arc power is bigger than normal when exceeding License Value when certain, remove clamp, again carry out the computing of electrode position balance, in new position three-phase electrode is carried out clamp and handle, specific as follows:

If A electrode current variable quantity is Δ Ia, B electrode current variable quantity is Δ Ib, C electrode current variable quantity is Δ Ic, the current change quantity deviate is DELTACURRENT, if A electrode displacement variable is HHA, B electrode displacement variable is HHB, and C electrode displacement variable is HHC, the position deviation permissible value is AEDISTANCE

Computational methods:

When electrode is in clamp state, promptly

(| HHA-HHB| 〉=AEDISTANCE) or

(| HHB-HHC| 〉=AEDISTANCE) or

(| during HHA-HHC| 〉=AEDISTANCE)

If Δ Ia 〉=DELTACURRENT or Δ Ib 〉=DELTACURRENT

Or Δ Ic 〉=DELTACURRENT, then remove electrode clamping.

In the present embodiment, transformer efficiency 12500KVA, primary side voltage 35KV, electric current 206A, current transformer change 250/5,900 millimeters of electrode diameters.The native system sampled signal: primary side three-phase current (taking from current transformer), secondary side voltage signal (directly obtaining), secondary side from transformer outlet row over the ground phase voltage 80V,

I _If=53450 (A) DELTACURRENT=15 (A)

I _{The dead band}=3%

Disclosed all features in this specification, or the step in disclosed all methods or the process except mutually exclusive feature and/or step, all can make up by any way.

Disclosed arbitrary feature in this specification (comprising any accessory claim, summary and accompanying drawing) is unless special narration all can be replaced by other equivalences or the alternative features with similar purpose.That is, unless special narration, each feature is an example in a series of equivalences or the similar characteristics.

The present invention is not limited to aforesaid embodiment.The present invention expands to any new feature or any new combination that discloses in this manual, and the arbitrary new method that discloses or step or any new combination of process.

Claims (1)

1. the method judging and handle of the electrode clamping effectiveness in the calcium carbide furnace control system, it is characterized in that: when the computer control electrode rises or descend, if electrode is by clamp, then the three-phase arc power is carried out the balance computing, bigger than normal when certain phase electrode arc power, when exceeding License Value, remove clamp, again carry out the computing of electrode position balance, in new position three-phase electrode carried out clamp and handle:

If A electrode current variable quantity is Δ Ia, B electrode current variable quantity is Δ Ib, C electrode current variable quantity is Δ Ic, the current change quantity deviate is DELTACURRENT, if A electrode displacement variable is HHA, B electrode displacement variable is HHB, and C electrode displacement variable is HHC, the position deviation permissible value is AEDISTANCE

When electrode is in clamp state, promptly

(| HHA-HHB| 〉=AEDISTANCE) or

(| HHB-HHC| 〉=AEDISTANCE) or

(| during HHA-HHC| 〉=AEDISTANCE)

If Δ Ia 〉=DELTACURRENT or Δ Ib 〉=DELTACURRENT

Or Δ Ic 〉=DELTACURRENT, then remove electrode clamping.