Supervisory computer control system

The objectives of the RH degasser supervisory control system are:

Receive information from shop management system necessary to define processing pattern and to schedule the heat.

Accurately calculate required alloy additions, scrap additions, decarburization and degassing time to deliver the heat to the caster.

Send required process setpoints to the control system.

Collect and report process parameters for each treatment.

Display current state of the heat.

Predict end conditions of the heat based on operator input for material additions and processing time.

Provide an operator interface for control of the process.

Automatically sequence the heat through processing cycles to complete treatment.

Allow operator to run process model against a heat that has not yet arrived and look ahead to schedule processing of the heat.

The software architecture is composed of seven subsystems: communications (COM); data acquisition and reporting (DAR); equipment control (ECL); metallurgical (MET); scheduling (SCH); system control and monitoring (SCM); and support (SUP). The database is a combination of data files and shares areas of memory.

There is a man-machine interface that consists of a group of displays which show an overview of the process model results on demand of the operator. A process summery display shows the progress of the heat. Another group of color graphic displays are updated each minute as the heat progresses to show the predicted values and trends of steel temperature, and carbon and oxygen content to the operator.

Lexical Exercises

I. Find the translation of the following words in the vocabulary, transcribe them, read aloud and remember..

· supervisory	· upleg
· vacuum degasser	· downleg
· consistency	· density
· meet requirements	· cause (v.)
· meet specifications	· reside
· carbon steel	· remove
· degassed steel	· reduce
· heat	· gravity
· composition	· confirm
· combine	· alloy (v)
· comprise	· objective
· treatment	· define
· immerse	· addition
· snorkel	· deliver
· depth	· predict
· draw (v.)	· provide
· hearth	· excess
· nitrogen	· run (v.)
· inject	· progress (v.)
· decrease	· content

II. Pay attention to the following groups of words with the same root. Define their part of speech and translate them into Russian.

alloy, to alloy, alloying, alloyed

add, addition, added, addendum

predict, prediction, predictor, predicted

provide, provision, provider, provided

exceed, excess, excessive, excessively

III. Find these misleading words in the article and give their correct translation.

· supervisory	· combine
· consistency	· inject
· composition	· progress
· objective	· specifications

IV. Match the English verbs given below with their Russian equivalents.

1. meet specifications	1. подтверждать
2. combine	2. погружать
3. inject	3. вызывать, быть причиной
4. comprise	4. соответствовать тех. требованиям
5. immerse	5. соединять
6. draw	6. впрыскивать, вдувать
7. decrease	7. обеспечивать, снабжать
8. meet requirements	8. удовлетворять требованиям
9. cause	9. отпускать (сталь)
10. reside	10. содержать, включать в себя
11. remove	11. уменьшать, ослаблять
12. reduce	12. уменьшать, сокращать
13. confirm	13. развиваться
14. alloy	14. удалять
15. define	15. определять
16. deliver	16. находиться
17. predict	17. сплавлять, делать сплав
18. provide	18. руководить, управлять
19. run	19. доставлять
20. progress	20. предсказывать

V. Answer the questions.

1. Why has the supervisory computer control for the RH vacuum degasser been developed?

2. How much steel does the degasser process?

3. What are the main steps of the degasser performance?

4. What are the objectives of the degasser?

5. What seven subsystems is the software architecture composed of?

6. What does a man-machine interface show?

7. What does a man-machine interface consist of?

8. Where is the progress of the heat shown?

9. Why are color graphic displays updated each minute as the heat progresses?

Grammar Focus

VI. Put the verb into the correct form: - ing or to + infinitive.

1. Do you mind ____ (work) until 20 o’clock today?

2. Kate likes ___ (type) English texts but she hates ______ (do) grammar exercises.

3. I can’t stand people _____ (tell) me what is good and what is bad.

4. I don’t like his lectures. I would hate _____ (attend) them regularly.

5. I would love _____ (come) to this meeting but unfortunately I have no time for it.

6. Sometimes I’d like ______ (learn) to play this computer game.

7. I very much enjoy _____ (talk) with you.

8. I clearly remember ____ (turn off) the computer before I left.

9. Someone pushed me and I couldn’t help _____ (drop) the remote control unit.

Speaking

VII. Give a summary of the article.

Text 6. EAF Savings by Systematic Process Tuning

Systematic monitoring of the performance of an EAF (electric arc furnace) enables fine tuning of operations to reduce consumptions and increase productivity. The advantages of such ‘tuning’ of furnace operation are such that the investment can pay for itself within just a few weeks.

Improvements in EAF steelmaking can be achieved by the application of systematic methods such as:

· quality assurance by routine checks;

· systematic evaluation of heat data on a statistic basis;

· analysis of process signals; and,

· on-line display of signals, especially the movement of the electrodes.

The key to efficient operation is to optimize process control and target evaluation of the data collected during a heat, i.e. to learn more about the melting process; recognize possibilities for improvements, and to avoid problems.

Because of the large energy input to modern ultra high power (UHP) furnaces, excess energy losses not only mean avoidable costs, but also can cause technical problems. The presence of hot spots and heat radiation from the arcs to the water cooled panels are causes of deviations from the normal progress and result in increased down times, loss of refractory lining and damages to the vessel. Presented proposals also support trouble shooting.

The methods have successfully been applied to scrap melting furnaces and also those with continuous material charging.

Quality assurance

Key cost variables, such as: tap to tap times, power on times, and specific consumption of electrical energy can be displayed for various blocks of heats.

Such an evaluation alerts the operator at any early stage to any drifting of results from the norm due to problems with the plant or melting process. Additional programs can find the reason for the drift.

This method is also good to check the results after any modifications to the plant, process or operation.

Statistical evaluation of heats

By identifying the heats that perform out of the norm, the reasons for the positive or negative influences can be found from their detailed heat reports.

Analysis of process signals

A combination of signals that determine or characterize the meltdown process can be selected and displayed as a function of the duration of the heat. The program ‘Analysis of process Signals’ is selected by a single function key on the terminal and the operator then selects from the menu:

· the number of heats to be evaluated;

· the parameters to be viewed; and

· the time range.

This helps the operator to learn more about the process in the vessel and thereby to determine the reasons for problems and to improve heat control.

Display of electrode movement

To establish favourable process conditions it is important to know what is going on in the vessel. To achieve this, an on-line display of the electrode movement offers a good base.

Economical aspects

The examples presented show that the high performance of modern computer technology makes it feasible to apply sophisticated tools to improve process control, plant maintenance and Quality Assurance.

Regarding the architecture of future automation systems, it is proposed to divide these into systems for the basic control of the furnace-which are expected to have a live time similar to any one of the mechanical parts, - and those with distributed intelligence. Due to the fast development of IT technology this type of dual system can be expected to be in place within just a few years.

Lexical Exercises

I. Find the translation of the following words in the vocabulary, transcribe them, read aloud and remember.

· target	· trouble shooting
· loss	· charging
· avoidable	· alert
· deviation	· drift
· down time	· identify
· refractory	· meltdown
· lining	· trace
· damage	· similar

II. Pay attention to the following groups of words with the same root. Define their part of speech and translate them.

improve, improvement, improved, improving, improver

sure, surely, assure, assurance, assured, assuredly

possible, impossible, possibility, impossibility, possibly

lose, lost, loss

avoid, avoidable, avoidance, avoiding

character, characteristic, characterize, characterized, characterizing

similar, similarity, similarly

distribute, distribution, distributor, distributed

III. In the text above, find the sentences which express the following points.

a. quality assurance by routine checks;

b. systematic evaluation of heat data on a statistic basis;

c. analysis of process signals;

d. on-line display of signals, especially the movement of the electrodes;

e. economical aspects.

IV. Answer the questions.

1. What’s the key idea of the effective EA furnace operation?

2. What causes avoidable costs and technical problems?

3. What are the reasons of increased down times?

4. What situations can lead to deviations in the process cost?

5. What signals can be selected by an operator to determine the meltdown process?

6. Why is it important to know what is going on in the vessel?

7. What do the examples presented in the article show?

8. What is proposed regarding the architecture of future automation systems?

9. Why can this type of dual system be expected to be in place within just a few years?

Grammar Focus

V. Translate the following sentences using these patterns.

Excuse me for ….ing …; Do you mind my …..ing …? It is worth …ing …; Would you mind ….ing …? I can’t help …ing; I am afraid of …ing …; She succeded in …ing; I’m looking forward to …ing ….

1. Эту лекцию стоит посетить.

2. Извините, что я пришел так поздно.

3. Будьте добры, дайте мне вашу ручку.

4. Ей удалось написать эту программу.

5. Вы не возражаете, если я посмотрю на работу этой компьютерной системы?

6. Я не могу не помочь вам в этом.

7. Я боюсь идти на завод одна.

8. Я с нетерпением жду вашего сообщения по электронной почте.

VI. Give a summary of the article.

Text 7. Dynamic Control System for Secondary Cooling of Continuous Casting Machines

Software to dynamically control the water spray supply to the secondary cooling zones of a caster has been developed which uses an average value for the heat transfer coefficient. This enables adjustments to the cooling water supply to be calculated more rapidly. Trials on a caster show this model to respond accurately.

One of the factors having an effect upon strand quality is an optimal cooling arrangement especially when casting steels are susceptible to cracking. Selection of the optimal cooling conditions and their precise achievement on a continuous casting machine (CCM) working at variable speeds of strand withdrawal stipulated by the continuous casting process (e.g. speed up, ladle change, pouring nozzle replacement, abnormal situations etc.) requires that the machine is furnished with a dynamic secondary cooling control system (DSCCS).

The DSCCS must:

· maintain preset water and air consumption over zones to ensure optimal strand cooling conditions at the steady casting speed;

· ensure respective change of water and air supply over the various CCN zones to prevent incorrect strand heating or cooling when the machine operates at various withdrawal speeds.

A secondary cooling control algorithm was developed based on mathematical models of strand solidification and experimental data on the heat exchange between spray nozzle and strand.

It should be noted that the most progressive secondary cooling control systems, developed in the recent years, are based on dynamic modeling of the strand temperature field.

A new dynamic model for slab secondary cooling has been developed in the Raahe steelworks of Rautaruukki (Finland), to control the supply of cooling water according to the temperature profile of the slab which is calculated in real time over its whole length.

Analysis of this model suggests that it has a time related deficiency when calculating heat condition in real time because of the large computational memory required and limited speed of the control processor, i.e. the calculation of temperature takes up to 5 seconds which in the real casting process delays corrections in the water flow to the secondary cooling zone. To use the model under operating conditions requires either very powerful computers or the use of parallel processors. This inevitably results in a rise in price, the need for a more complicated secondary cooling control system and puts doubt on the reliability of the system.

OAO ‘Uralmash’ is one of the largest plantmakers involved in the design and manufacture of heavy steelmaking equipment. Established in 1933, the Company is located at Yekaterinburg in the centre of Russia and produces more than 200 different types of machines for the iron and steel, mining and oil and gas industries. These are sold to enterprises in Russia, CIS, Europe, Asia and Africa. For more than 30 years, OAO ‘Uralmash’ has been the major supplier of continuous casting machines for slab in Russia and the CIS. In this time, 70 machines have been produced and put into service.

OAO Uralmash has developed a dynamic model to control secondary cooling of strand cast on a CCM using an alternative approach requiring less computer power. When developing the secondary cooling control algorithm a strand solidification mathematical model is used which employs the real time temperature profile; mean values of heat transfer coefficients (over sections of secondary cooling zone) and water consumption for the whole range of casting speeds.

OAO Uralmash has developed a DSCCS simulation program for algorithm debugging based on the mathematical model. Debugging of algorithm, determination of its parameters and demonstration of its proper functioning were carried out on the simulation model.

Unlike the System of Raahe where the operational differential equation for heat conduction has to be solved in real time, this new approach does not require this so saving considerably computer resources.

Lexical Exercises

I. Find the translation of the following words in the vocabulary, transcribe them, read aloud and remember.

· spray (n, v.)	· stipulate
· supply (n, v.)	· ladle
· caster	· pouring
· casting	· nozzle
· value	· furnish
· heat (n, v.)	· consumption
· transfer (n, v.)	· ensure
· adjustment	· operate
· trial	· solidification
· respond	· slab
· accuracy	· deficiency
· effect	· conduction
· strand	· approach (n. v.)
· susceptible	· mean (adj.)
· cracking	· debugging
· continuous casting machine	· withdrawal

II. Pay attention to the following groups of words with the same root. Define their part of speech and translate them into Russian.

cool, cooling, cooler, coolant

heat, to heat, heating, heater.

withdraw, withdrawal

to adjust, adjustment

solid, solidification, solidify

conduct, conduction, conductor

III. Find these misleading words in the article and give their correct translation.

· accurately	· effect
· furnish	· operate
· ensure	· conduction

IV. Match the English verbs given below with their Russian equivalents.

1. spray	1. обеспечивать
2. supply	2. отливать
3. cast	3. проводить
4. heat	4. затвердевать
5. transfer	5. работать
6. effect	6. заливать
7. withdraw	7. нагревать
8. stipulate	8. охлаждать
9. pour	9. разбрызгивать, распылять
10.furnish	10. подавать
11.consume	11. приближаться
12.ensure	12. поглощать, расходовать
13.operate	13. снабжать
14.solidify	14. предусматривать
15.conduct	15. переносить
16.approach	16. осуществлять
17.cool	17. вынимать, извлекать

V. Answer the following questions.

1. When is optimal cooling arrangement especially important?

2. What are main functions of a dynamic secondary cooling system?

3. What served the basis for DSCCS?

4. Why has a new dynamic model for slab secondary cooling been developed in Raahe steelworks?

5. What does the use of this model under operating conditions require?

6. In which way is the model developed in Uralmash different from the previous model?

7. What is the simulation model needed for?

8. What is the advantage of the model developed in Uralmash?

9. What mathematical model is used when developing the secondary cooling control algorithm?

10. What does a strand solidification mathematical model employ?

Grammar Focus

VI. Translate the sentences paying attention to the form and function of Participle I.

1. Constructing the algorithm programmers use the techniques of top-down design.

2. Existing scale car stock houses have been changed to conveyor fed systems.

3. Slabs are cast in 9 and 10 in. thicknesses and widths ranging from 39 to 62 in.

4. Having typed the text containing the information about a new machine the operator showed it to the engineer.

5. One of the factors having an effect upon strand quality is an optimal cooling arrangement.

6. Analysis of this model suggests that it has a time related deficiency when calculating heat condition in real time.

7. The support engineer giving remote instructions to the customers makes a useful job.

8. Information is stored on different generations of computer using different software.

9. Branching out from the root directory, users create their own directories (also called subdirectories) to organize their program files and data files.

Speaking and Writing

VII. Tell the class what you have learned from the article about OAO “Uralmash”.

VIII. Write an annotation to the article.

Text 8. The Use of PLC’s and Supervisory computers for Blast Furnace Stockhouse Automation

Automation of a blast furnace stockhouse substantially improves production and iron quality by eliminating operational variances caused by personnel, equipment and charge materials.

A blast furnace stockhouse system is a bulk material weighing, batching and delivery system. Weighed materials are gathered in batches in an order defined by a charge program and delivered to the top of a blast furnace. The furnace is cycled to charge the materials. The charge program is developed either empirically or by scientific calculations to produce molten iron with the correct composition. Iron composition and blast furnace efficiency are directly related to the variances in the charge program. Operational variances are due in part to: operator error; equipment malfunction; and changes in the charge material. These uncontrollable variances necessitated the development of stockhouse control systems.

Control systems for stockhouses have been employed for decades. Originally, charge programs were written on chalk boards and the charge program was in the hands of the scale car (вагон-весы) operator. Initially, all materials were gathered manually. The scale car operator kept track of the charge program by moving wooden pegs on a board and observing the furnace stock level by a mechanical stock rod with telltales attached to a cable.

In the last decades, with the use of PLC’s and supervisory computers, totally automated stockhouses have been built and existing scale car stockhouses have been changed to conveyor fed systems. These conveyor stockhouses operate without a scale car and scale car operator, and employ advanced control systems using computers that direct the process based on a defined charge program. Over the same period, stockhouses with manual ore and stone gathering using a scale car automatic coke gathering have been upgraded with advanced control systems.

Automatic stockhouses are controlled by a hierarchical system of computer and PLC’s. The computer system collects data for daily and historical reports which include material usage and furnace status information.

Automatic stock house have the following functions:

· Charge director.

· Material gathering.

· Material delivery.

· Material tracking.

· Diagnostics.

· System status.

· Data acquisition and reports

To implement the automatic stockhouse functions listed, a control system must exist. Many control configurations are possible but two primary configuration rules should be followed. Control equipment should be selected for the purpose it was primarily designed. For example, PLC’s should not be used where a computer is more suited and vice versa. PLC’s are applied to real-time sequential logic problems. They are used to control the stockhouse equipment (weigh hoppers, conveyors, skip and furnace top). PLC’s are directed by a stockhouse computer which maintains charge programs, records material usage and provides diagnostic information. It is used for operator interface, data collecting and reporting. Color graphic displays, driven by the PLC’s or the computer system, provide system status information.

Lexical Exercises

I. Find the translation of the following words in the vocabulary, transcribe them, read aloud and remember.

· stockhouse	· rod
· eliminate	· telltale
· variance	· fed system
· bulk	· ore
· weighing	· coke
· batching	· gathering
· batch	· upgrade
· iron	· acquisition
· due to	· primary
· malfunction	· vice versa /'vaIsI'vÆ:s@/
· manually	· hopper
· scale car	· skip
· peg	· furnace top
· stock	· molten

II. Pay attention to the following groups of words with the same root. Define their part of speech and translate them into Russian.

to weigh, weight, weighing, weighed

batch, batching, batched, batcher

acquire, acquired, acquisition, acquisitive

prime, primary, primarily, primal

know, knowledge, known, acknowledge

contribute, contribution, contributor, contributory

III. Use these words to fill the gaps.

equipment, stockhouse, furnace, batching, composition, data, vise versa, weighed, iron, top, primarily, improves

1. A blast furnace _____ system is a bulk material weighing, _____ and delivery system.

2. The charge program is developed to produce molten _____ with the correct _____.

3. _______ materials are gathered in batches in an order defined by a charge program and delivered to the ____ of a blast furnace.

4. The computer system collects _______ for daily and historical reports which include material usage and furnace status information.

5. Control _____ should be selected for the purpose it was _____ designed.

6. For example, PLC’s should not be used where a computer is more suited and______.

7. Automation of a blast ______ stockhouse substantially ______ production and iron quality.

IV. Find the answers in the article to these questions.

1. What does automation of a blast furnace improve?

2. Where are weighed materials delivered?

3. Why is the charge program developed?

4. What is iron composition directly related to?

5. What are the reasons of operational variances?

6. How long have control systems for stockhouses been employed?

7. What have scale car stockhouses been changed to?

8. What are automated stockhouses controlled by?

9. What are PLC’s directed by

Grammar Focus

V Think of questions to these answers.

a. Automation of a blast furnace stockhouse substantially improves production and iron quality.

b. The furnace is cycled to charge the materials.

c. The charge program is developed either empirically or by scientific calculations.

d. PLC’s are used to control the stockhouse equipment.

e. The computer system collects data for daily and historical reports.

f. In the last decades, existing scale car stockhouses have been changed to conveyor fed systems.

g. Control systems for stockhouses have been employed for decades.

h. Color graphic displays provide system status information.

i. These conveyor stockhouses operate without a scale car and scale car operator.

j. The scale car operator kept track of the charge program.

k. Control equipment should be selected for the purpose it was primarily designed.

l. Many control configurations are possible but two primary configuration rules should be followed.

VI. State the functions of Participle II and translate the sentences into Russian.

1. Automation of a blast furnace stock house substantially improves production and iron quality by eliminating operational variances caused by personnel, equipment and charge materials.

2. Color graphic displays driven by the PLC’s or the computer system provide system status information.

3. To implement the automatic stockhouse functions listed a control system must exist.

4. In the last decades, with the use of PLC’s and supervisory computers, totally automated stockhouses have been built and existing scale car stockhouses have been changed to conveyor fed systems.

5. Just as it is hard to find what you are looking for in a cluttered, information packed office, so it is with computer storage of data.

6. When installed, an automated spray control system started to track the slab through the machine and optimize spray rates in each zone based on the history of the part of the strand in that zone.

7. In most casting machines cooling sprays are computer controlled.

8. Thus, a simplified slab tracking algorithm was employed that could be handled by a programmable logic controller which optimized spray rates.

Speaking and Writing

VII. Give a summary of the text.

VIII. Write an annotation to the article. Use these patterns.

…..is (are) discussed (described, analyzed, shown)

It is noted (stressed) that….

The author pays special attention to…

Text 9. Computer Control of Cooling Sprays on Vintage Slab Casters

In the continuous casting process, water sprays are directed onto the shell of a partially solidified slab or bloom to aid in heat extraction and solidification. The cooling spray flow rates must be adjusted as the casting speed varies so that the strand is uniformly cooled. In most casting machines cooling sprays are computer controlled.

The continuous casting plant at McLouth Steel in Trenton, Mich., consists of four single-strand casters. Slabs are cast in 9 and 10 in. thicknesses and widths ranging from 39 to 62 in. The plant casts low-carbon, aluminum-killed strip grades, but also casts higher carbon and alloy steels. There are eight spray control zones, designated as 1A, 1B, 2 Top, 2 bottom, 3 Top, 3 Bottom, 4 Top and 4 Bottom. The spray control hardware consists of control loops for each of the eight control zones.

McLouth contracted Designers Edge to design a supervisory spray control system. Cost constraints dictated that a simplified system had to be employed but the water flow rate calculations demanded computational sophistication. The solution was a programmable logic controller capable of performing floating point mathematical operations. The PLC would calculate the proper set points for each spray control zone based on casting speed and send these set points to the appropriate loop controllers via an analog output.

The first step in creating computer control was to develop equations expressing the desired water flow rate for each zone. The PLC could read the casting speed from the machine tachometer and calculate the correct flow set point for each zone.

When an automated spray control system was installed on a machine, it was proposed that the spray control program would have the ability to track the slab through the machine and optimize spray rates in each zone, based on the history of the part of the strand in that zone.

The PLC programs were modified to track the passage of slab slices through the machine in the course of casting. The slab tracking was accomplished in the following steps:

· At each scan of the PLC program, the current casting speed was read.

· The program integrated the speed to calculate the incremental movement of the strand since the last scan.

· The position of each slice was updated to reflect the incremental movement.

· The age of each slice was incremented by the period of one scan.

· New effective values were calculated for each slice in the machine.

· Each time a total of 4 in. had been cast, all slices were moved down one position in the PLC memory and a new slice was initialized.

Thus, a simplified slab tracking algorithm was employed that could be handled by a programmable logic controller which optimized spray rates. The control scheme successfully maintained uniform slab temperatures and significantly reduced spray-related slab defects such as bowed slabs, transverse cracks and centerline porosity.

Lexical Exercises

I. Find the translation of the following words in the vocabulary, transcribe them, read aloud and remember.

· caster	· thickness
· vintage	· aluminum-killed steel
· bloom	· bottom
· aid	· floating point
· extraction	· incremental
· adjust	· bowed

II. Pay attention to the following groups of words with the same root. Define their part of speech and translate them into Russian.

adjust, adjusted, adjustment, adjusting, adjuster

thick, thickness, thicken, thickener

increment, incremental. incrementation, incrementor, incremented

track, tracking, tracker, trackage

simple, simplify, simplified, simplicity

III. Match each problem mentioned in the article with the suitable suggestion.

· Problems	· suggestions
1 not uniform casting speed	A.PLC performing floating point mathematical operations
2 sophisticated calculations	B.modified PLC programs
3 slab tracking	C.adjusting cooling spray flow rates
4 bowed slabs	D.control scheme

IV Complete each sentence with the appropriate verb.

was updated, were calculated, was to develop, must be adjusted, maintained, were modified, reduced, consists

1. The first step in creating computer control _______ equations expressing the desired water flow rate for each zone.

2. The control scheme successfully ______ uniform slab temperatures and significantly _____ spray-related slab defects such as bowed slabs, transverse cracks and centerline porosity.

3. The position of each slice ________ to reflect the incremental movement.

4. The PLC programs _______to track the passage of slab slices through the machine in the course of casting.

5. The continuous casting plant at McLouth Steel in Trenton, Mich., _____ of four single-strand casters.

6. New effective values ________ for each slice in the machine.

7. The cooling spray flow rates ________ as the casting speed varies so that the strand is uniformly cooled.

V. Find the answers in the article to these questions.

1. Where are water sprays in the continuous casting process directed?

2. Why must the cooling spray flow rates be adjusted?

3. What does the continuous casting plant at McLouth Steel consist of?

4. What are the dimensions of slabs?

5. What are the functions of the PLC?

6. What was the first step in creating computer control?

7. Why was a simplified slab tracking algorithm employed?

Grammar Focus

Дата добавления: 2015-10-26