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8.Control Unit


8.1.General Description

Boxes contain all devices for the drive and control of uses in the above described systems and power switches for the different motors.

They are complete with a switch for the door-lock, buttons of start, stop and light signal, reading instruments and control of accessories, remote control switches, transformers, fuses, temperature relays and connection terminal boards.

These devices, contained in metallic boxes, are easily accessible after having turned off the voltage when you have to open the door. The device is powered by a grounded neutral three-phase voltage at 400 V and is prearranged according to CEI rules; the control circuits run at 24 V 50 Hz.

8.2.Electric Panel Board of Hot Dip Galvanizing Department

The control electric board of all components included in our supply should be placed in a suitable room close to the furnace, in order to allow a quick remote control. The auxiliary circuit is controlled by the electromechanical logic relay and the auxiliary voltage inside the board is 110 Volt. All major functions are monitored and continuously "alarmed" with storage of the event. They are:

General functions: PLC in anomaly with thermal switch released.
Dryer: High temperature of heating air of the dryer. Low air pressure of the dryer.
Furnace of galvanizing: High zinc temperature in two areas. Low temperature of zinc in 2 areas. High and low gas pressure for burners. Low air pressure of burners in 2 areas. Zinc leakage. Insufficient vacuum control for the draught of combustion fumes. Detection of gas leakage in the furnace room.

Filtration of white fumes: Low air temperature of counter washing. High delta pressure of filtering.
Board sizes : 3,000 x 800 x 2,200 (h) mm
Voltage : grounded neutral three-phase voltage at 380 Volt.
Given power : 1 HP.

Panel in self-supporting metal sheet, painted in RAL 7032 grey, designed and built according to CENELEC EN60204.1 and VDE 0113 standards with a front and back door, protection class IP54, including:
Indoor lighting, safety device against the door opening, indoor warning lights to signal the presence of voltage. General switch, voltmeters, ampere meter, thermal remote control switches. Tele-overload cut-outs, remote control switches, thermal switches, fuses, service relays, electronic timers, accessories.
Push-button panel, switches, warning lights, indicating plates.
A 4 colour synoptic panel and with lighted LEDs.
Process instruments, including:

A pyrometer, a microprocessor regulator for the proportional control of temperature of hot air recirculation of the dryer, of electronic digital type and PID regulation.
A pyrometer, a liquid crystal indicator for the control of temperatures in various points of the plant, connected to a switching gear case of thermocouple lines to allow controls in various areas for a total of 6 different channels.

A digital electronic pyrometer, a microprocessor regulator for the control of zinc temperature at a high level with PID action.A pyrometer, a microprocessor regulator for control of high and low alarm temperature of zinc, of electronic digital type and with an ON/OFF control.
A pyrometer, a liquid crystal indicator for the control of zinc temperatures at low level, linked to a recorder. A magnetic vacuum gage with electric contacts with a photoelectric cell for the control and adjustment of the internal vacuum of furnace.

A pyrometer, a microprocessor regulator for the control of air temperature for filter counter washing of electronic digital type and with an ON/OFF control. A magnetic vacuum gage with electric contacts with a photoelectric cell for the control and adjustment of the P Delta of filter, with two operation thresholds. A self-test electric device of safety conditions of the system and of automatic start after the power failure. An alarm device via telephone with two pre-recorded messages.

Procedure of automatic start of plants with the return of power supply, an emitter of prerecorded alarms via telephone, obtained from the control board of the galvanizing department.

8.3.Automatic Paperless Hot Dip Galvanizing Plant Managing Software System

What is and how works 4Glv system?

4Glv is an information software able to collect and transfer data and information between pc and servers. Using a mix of networks connection, by cable, wireless and internet. The logic unit of elaboration are divided in 3 levels (L1, L2, L3). This system are a mix of hardware and software able to collect and distribute data during all the working process. Able to detect dynamically event and actions in the process flow. Collect and show data and times with views and graphics.

Purpose of the System 4Glv

The principal goal of this system is collect data and results of process, store problems and notes of production of each step of production and make historical representation.

  • Is possible to use this data in a lot of tree view and graphics, and export data for other uses.
  • Are possible to plan and maximize the capacity of plant.
  • Level-1, acquire data from the process and exchange to Level2;
  • Level-2, exchange data to Level1 and store it inside a SQL database;
  • Level-2, enable to correct and adjust in stored data;
  • Level-2, show data in various modes : User View; Specific report;
  • Level-2, exchange data with L3 (import data to use and store);
  • Level-2, process data and schedule automatically production.

The capability of this system is following: Level1 (terminals) e Level2 (PC supervisor).Terminal Level1.

  • Acquires from operator time articles and lotto charged in production line;
  • Acquires from operator of thickness of zinc measured;
  • Automatically acquires weight of materials charged (load cell)
  • Checks on the congruity of the acquired data (length, type, etc..);
  • Data entry via manual operations run by a user interface that prevents input errors, events, eg. Event end without the beginning, etc..;
  • Data queues for temporarily storing the data acquired awaiting transfer to L2;
  • Automatic and secure transfer of data to L2-managed transactions via a two-phase commit).

Functionality of PC Supervisor L2

  • Automatic data exchange L2 - L1 (process 4Glan Handler);
  • Automatic data exchange L2 - L3 (process Import/Export Data Handler);
  • Real time display of the state of (stages beam open / execute, articles-in batch processing);
  • Environment Maintenance System database SQL;
  • View, insert, edit of configuration data;
  • View, insert, edit of data batches, packaging, received from L1;
  • Management of non-conformities found in the input and output, with printing of the documents provided by the quality system;
  • Bar codes Print and data associated with the production (articles, operators, packaging, etc..) That control characters (function keys, letters, figures, etc..) For terminals L1;
  • Managing access to the system by defining users and passwords with different levels of qualification; Functionality of PC Supervisor L2
  • Programming of the daily production;
  • Production of summary reports on data collected.
  • Scheduling of daily work (process EiSched).
  • Web services to allow access to the data base to handheld devices used for the management of the stores.
  • NOTE: some of the features listed above are not available with the basic version of the system 4Glv.


This chapter describes an essential key elements of the computer network of the factory.

The network types

The communication between the supervisor and PC terminals for data collection are make true Ethernet connection, by cable or wireless.

The connected components

  • A supervisor PC (Microsoft Windows) for the NPX data collection system that receives data from the batch of items-management system (server);
  • A client PC connected to a printer for label production batch of items-(NPX delivery) can read data from the ERP system;
  • Number of terminals 2 NPX L1 (preparation, packaging) connected with the supervisor PC via Ethernet (TCP / IP).
  • Number 1 WINDOWS PC for viewing and managing the production data in Ethernet local area network (Customer).
  • A terminal running Microsoft Windows (IPC) for the automatic refilling of the acid in the tanks (if provided).
  • NOTE: All PCs and terminals are physically connected via Ethernet cards and cables or Wi-Fi (not included). The terminals are physically realized with PC properly protected for factory conditions.
    There are essentially five applications that manage data on the PC Supervisor:

  • The process 4GlanHd (4Glan Handler), for the management of communications between the PC and terminals L1 Supervisor;
  • The process IEDHL (Import / Export Data Handler), for managing data exchange between PC Supervisor L2 and L3 management system;
  • The process 4GSched, for scheduling batch to hot dip galvanizing.
  • The user program 4Glv, management and visualization of all the production data collected by the system (the only of the four applications mentioned can also be installed on Windows machines as well as PC Supervisor);
  • The data base (DB), i.e. the container of the data recorded in the PC Supervisor. The set of processes / programs in the PC Supervisor system is called 4Glv. The difference in names between processes and programs 4Glv is that while the processes are launched when you start the PC and are always active, programs can be turned on and off as needed.


The flow of the material to hot dip galvanizing

When the material to hot dip galvanizing arrives at the factory is first weighed, then ranked and placed in the storage material. Each new incoming material is identified by the term batch of material.

Within a batch there maybe various different articles. After a variable time interval, the processing is initiated, divided into several phases, in order to hot dip galvanizing the material itself.

The cycle ends when the material, after being galvanized and packaged, is ready to be returned to customers. The recording of data about lots of material The current information system that provides data about lots of material to be recorded by four different systems, each operating in different fields:

1. The operating system, which handles billing and data arrival of batches of material (bubbles of work);

2. The data collection system feed production NPX, which receives data of the batches by the (system 1) and, via the terminals of production NPX, records the stages of processing by the cross-beam articles.

3. The control system feed production (4Glv) that runs on Windows PC, allows you to manage and display data from different points of the production plant.

4. The management-batch label printing articles NPX that allows printing of labels with bar code-batch of articles. The generation of working documents is assigned to a management module of the program (not NPX) Job ticket of material lot For each new arrival of a batch of material generates a job ticket, where are recorded lot number and several others data including customer data, description, N. the packing slip, etc.. The N. lot is a number, max. 7 digits, progressive and unique in the calendar year. To make lots of unique numbers for several years, all programs use it as NPX registration key pair given by the last two digits of the year + the sequence number of the batch in the year, eg. 120000001. The generation of the bubbles of work is entrusted to a module of the management program (not NPX).

After each creation or modification of a bubble of work, the management program creates a new swap file, the name that uniquely identifies the batch to which it refers, contains the new data of the bubble. This file is then used by the exchange system 4Glv to maintain the batch data aligned with those of the management program.

NOTE: To combine the batch data with greater security, it is appropriate that programs receive NPX located on the Server PC, the program management, data notes lots of work before it begins its work.

Printing Labels

5. The NPX program dedicated to printing labels Articles - lot (one of the PC Client) checks to see if there are new batches, if so puts them in the list of items-Lot for which you must print the appropriate label.

Data exchange between PC and terminal NPX Production Supervisor

Once the identification of a batch have been transferred and included in the database of the supervisor PC, these are available to be sent to the output terminal NPX who request it in order to display the associated data, eg. customer name, date of arrival of the lot, etc.. Articles-lot hanging on each beam in the preparation phase, the code key and people used to hang from the rafters materials;

  • The times of beginning and end of the preparation, pickling, galvanizing and packing; The data come from pickling and galvanizing PLC management.
  • The weight of the material hanging from the beam preparation and packaging,
  • In galvanizing, the zinc bath temperatures at the beginning and end of zinc, (if the data coming from PLC system management)
  • In packaging, the number of packages used for each batch of a beam and the measurements of the thickness of the zinc made the material being processed.

For every beginning and end of a processing stage beam, the recorded data from terminals NPX, are transmitted to the PC server and database production progress is updated in near real time.

The system then keeps track of the following data:

1. Times and phases traversed by each beam;
2. The number of beams used to work every single lot together with the partial and total processing time for each step.
Each beam is identified by a physical number from 1 to 99 which represents the fixed code assigned to the beam. They can also be handled details of the beams, which are actually "packages" of material, and are handled differently than the others (there may be multiple packages simultaneously in the same pickling tank and not have the packing stage) . Given that the same beam can repeat the processing cycle (preparation ... packing) several times a day, individual instances of a beam are identified using the date and time of the start preparation.

Every beginning preparation beam opens a new period of work identified for the beam, as mentioned above, the date and time. A period of machining beam is generally considered to be closed with the end of phase packing. Given the time of start and end phase of the beam and the code worked at that stage, the supervisor's task is to associate these data are needed of the beam with the same beam code whose period is included in the phase indicated.