CLIAMS:1. A networking system for control and integration of various mechanisms of cooling beds and bar shear area of mill comprising

PLC based intelligent control desk & remote I/Os based control for controlling of Cooling Beds & Bar Shears operation mechanisms;

said PLC interfaced based Intelligent Control Desks & HMI providing for operator’s Interface;

said PLC based intelligent control desk operatively linked to various electrically operated valves enabling reduced communication network for facilitating receiving instantaneous information from field devices of the mill at centralized location for executing control functions.

2. The networking system as claimed in claim 1 comprising
user interface operatively connected with the communication network for facilitating the user to monitor status and operation of the field devices.

3. The networking system as claimed in anyone of claims 1 or 2, wherein the Intelligent Control Desk comprises two PLC, six Remote I/O based systems, two programmable terminals and one HMI terminal for user interface, each of having networking nodes adapted for establishing interconnection through the reduced cold redundant communication network.

4. The networking system as claimed in anyone of claim 1 to 3 , wherein the remote I/Os for the bar shear are placed inside bar shear operator desks at each cooling bed for replacing signal cables with an Ethernet communication cable and thus reducing the communication network path.

5. The networking system as claimed in anyone of claims 1 to 4, wherein the remote I/O based Operator desks are placed in Control Pulpit having networking nodes for interconnecting with their respective PLCs through optical fibre cable.

6. The networking system as claimed in anyone of claims 1 to 5, comprises a Solenoid panel having the networking nodes for connecting with the Remote I/O based bar shear operator desks through the reduced cold redundant communication network and facilitating controlling operation of solenoid-operated field devices locally terminated at the Solenoid panel from the operator desks.

7. The networking system as claimed in anyone of claims 1 to 6, wherein the solenoid- operated field devices for field operations in the bar shear area preferably includes gauge heads up / down, stopper raise / lower, hold down raise / lower, shear cut and like.

8. The networking system as claimed in anyone of claims 1 to 7, which interfaces with inputs and outputs of the field devices and receives inputs through auxiliary contacts of existing relays with proper isolation.

9. The networking system as claimed in anyone of claims 1 to 8, wherein control and integration of various mechanisms of cooling beds and bar shear is adapted to render provision of testing the Control Desk electrical wirings, interlocks and plant logics well before actual installation and hence significantly reducing final installation as well as commissioning time.

10. The networking system as claimed in anyone of claims 1 to 9, comprising centralized control of the cooling beds and bar shear area of the mill enabling reduced electrical downtime and cobble generation by reducing control cables from bar shear and Control Pulpit resulting faster diagnosis of faults.

Dated this the 25th Day of June, 2014 Anjan Sen
(Applicants Agent)
IN/PA-199 ,TagSPECI:FIELD OF THE INVENTION:
The present invention relates to an improved control desk with remote I/O inside the desk (Intelligent Control Desk) for Centralized PLC control of Cooling Beds & Bar Shears in Merchant Mill of a steel processing plant. In particular the present invention is directed to develop a networking system for control and integration of various mechanisms of cooling beds and bar shear area of the mill.

BACKGROUND OF THE INVENTION:
Controlling and integrating the various mechanisms of cooling beds and bar shear area of a steel processing mill is an important and crucial aspect for facilitating the production of different steel product such as plain rounds & TMT bars. In steel processing plants, there are two cooling beds are used to accommodate the final products. The bars are transferred to both the cooling beds from “run off table” via “rotary kick off” operation. The different mechanisms like rotary kick off, shuffle bar eccentric, shuffle bar lifting, carry over, run off table, push off and back shear table are used in both the cooling beds & bar shears area for transportation of bars from both the cooling beds area to bar shears area.

The existing method for controlling the mechanisms of cooling beds and bar shear area of the steel processing mill or plants are not efficient and often fail due to failure of old & obsolete hard wired relay based logic resulting in stoppage of the Mill & Cobble generation. The Bar shear mechanism used to fail mainly because of failure of cable network in the field. In the existing systems for controlling the mechanisms Bar shear a huge cable network between bar shear & the electrical control room is used which is the major drawback of these systems as the failure of any of these cable used to result in stoppage of the mill.

The Field sensing devices & control system used to give frequent problems leading to mill downtime & production loss. (Malfunctioning of insulated earth rollers for kickoff operation) and In absence of any centralized monitoring system in the existing systems, fault finding was time consuming. Also there was no on-line diagnostics & operator feedback system resulting in delay in trouble shooting & localization of electrical faults.

Also, in existing systems, all the I/O signals were connected to the control panel through hardwired multi-core cables. Long distance multi-core control cables used to run from various operator desks to electrical control rooms resulting very high electrical delay in Cooling Beds & Bar Shears Area.
It is thus there has been always a need for centralized automation system which can Control and integrate the various mechanisms of cooling beds and bar shear area of a steel processing mill and overcome all the problems of the old systems.

OBJECT OF THE INVENTION:
It is thus the basic object of the present invention is to develop system which would be adapted to control and integration of various mechanisms of cooling beds and bar shear area of mill.

Another object of the present invention is to provide networking system which would be adapted to integrate various mechanisms of cooling beds and bar shear area of mill by involving reduced network path.

Yet another object of the present invention is directed to provide a networking system which would be adapted to facilitate instantaneously acquire information from field devices of the mill at centralized location for executing control functions.

A still further object of the present invention is directed to provide a networking system which would be adapted to facilitate user to centrally control all solenoid-operated field devices of the cooling beds and bar shear area of mill.

SUMMARY OF THE INVENTION:
Thus according to the basic aspect of the present invention there is provided a networking system for control and integration of various mechanisms of cooling beds and bar shear area of mill comprising

PLC based intelligent control desk & remote I/Os based control for controlling of Cooling Beds & Bar Shears operation mechanisms;

said PLC interfaced based Intelligent Control Desks & HMI providing for operator’s Interface;

said PLC based intelligent control desk operatively linked to various electrically operated valves enabling reduced communication network for facilitating receiving instantaneous information from field devices of the mill at centralized location for executing control functions.

According to another aspect of the present invention, the present networking system comprises user interface operatively connected with the communication network for facilitating the user to monitor status and operation of the field devices.

According to another aspect in the present networking system, the Intelligent Control Desk comprises two PLC, six Remote I/O based systems, two programmable terminals and one HMI terminal for user interface, each of having networking nodes adapted for establishing interconnection through the reduced cold redundant communication network.

According to yet another aspect in the present networking system, the remote I/Os for the bar shear are placed inside bar shear operator desks at each cooling bed for replacing signal cables with an Ethernet communication cable and thus reducing the communication network path.

According to a further aspect in the present networking system, the remote I/O based Operator desks are placed in Control Pulpit having networking nodes for interconnecting with their respective PLCs through optical fibre cable.

According to yet another aspect of the present invention, the present networking system comprises a Solenoid panel having the networking nodes for connecting with the Remote I/O based bar shear operator desks through the reduced cold redundant communication network and facilitating controlling operation of solenoid-operated field devices locally terminated at the Solenoid panel from the operator desks.

According to a further aspect of the present networking system, the solenoid- operated field devices for field operations in the bar shear area preferably includes gauge heads up / down, stopper raise / lower, hold down raise / lower, shear cut and like.

In accordance with another aspect of the present invention, the present networking system interfaces with inputs and outputs of the field devices and receives inputs through auxiliary contacts of existing relays with proper isolation.

According to a further aspect in the present networking system, the control and integration of various mechanisms of cooling beds and bar shear is adapted to render provision of testing the Control Desk electrical wirings, interlocks and plant logics well before actual installation and hence significantly reducing final installation as well as commissioning time.

According to yet another aspect of the present invention, the present networking system comprises centralized control of the cooling beds and bar shear area of the mill enabling reduced electrical downtime and cobble generation by reducing control cables from bar shear and Control Pulpit resulting faster diagnosis of faults.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES:
Figure 1 shows a PLC Network Architecture for control of Cooling Beds a Bar Shears in accordance with the present invention.
Figure 2 illustrates a conventional Bar Shear Control Desk with huge network of control cables running between the desk & the electrical control panels, around 100 meters away from the desk.
Figure 3 shows an embodiment of the present Bar Shears Control Desk with remote I/O inside it with only one communication cable running between the Intelligent control desk (remote I/O inside it) & the PLC panel, around 100 meters away from this desk.
Figure 4 illustrates the HMI screen snap shot of Bar Shear Desk-1.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING FIGURES:
In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and illustrate the best mode presently contemplated for carrying out the invention. The accompanying figure 1 depicts the network for new PLC & remote I/Os control architecture for control of Cooling Beds & Bar Shears operation mechanisms. The architecture shows the PLC which replaces the old & obsolete relay based control logics. The PLC is interfaced with the Intelligent Control Desks & HMI i.e. Operator’s Interface, the programming unit and various electrically operated valves linked to PLC system.
In the present networking system as depicted in the accompanying figure 1, consists of control and integration of various mechanisms of the cooling beds and bar shear area of the mill through two PLC and six Remote I/O based system. All the eleven nodes including two programming terminals and one HMI terminal are connected through a cold redundant communication network covering a total length of 1.2 km approximately. The interconnection among all the nodes is on TCP/IP through multi mode Fibre-Optic Cable (Ref.2) and CAT6. All required networking accessories incorporated in the system are of industrial grade to make the network reliable. A cold standby of the network has also been installed for quick changeover in case of damage to network cable anywhere. Each node has adequate number of Input and Output modules, which are Digital and/or analog to interface all the required signals from the field as required for the application.
The remote I/Os for bar shear signals are placed inside the new bar shear operator desks at each cooling beds. These have replaced the bunch of signal cables (Figure2) with an Ethernet communication cable (CAT 6 in this case) as shown in Figure 3. All the solenoid-operated field operations in bar shear area like gauge heads up / down, stopper raise / lower, hold down raise / lower, shear cut etc are locally terminated at newly installed Solenoid panel. This panel has two nos. of networking nodes in which network nodes from Remote I/O based bar shear operator desks are connected. The commands for the operation of solenoids are given by the operators from the switches and push buttons of bar shear operator desks.
Similarly remote I/O based Operator desks are placed in Control Pulpit -10 in which there are two nos. of networking nodes interconnected with their respective PLCs through OFC (optical fibre cable). Various field signals and multiple mode operations of drives are controlled by this desk.
The entire system required interfacing with a large number of inputs and outputs in the existing shop electrics. Detailed design work was carried out to formulate the complete I/O listing before commencement of other activities. Input signals from all field control devices have been taken to the system with proper isolation. Majority of digital inputs have been taken through auxiliary contacts of the existing relays. Depending upon the location of the field signals, relay boards have been provided at various places and control of the drives have been interfaced with these relay boards. Signal interfacing work involved extensive conduit and cable laying, and termination.
In order to address the absence of any online diagnostics tools or indications, and the huge time overhead in fault finding, which were frequent in the existing system, one HMI station has been provided in the Electrical control room for development of HMI screens to monitor critical operations.
Software design and development involved PLC application program for display of information in HMIs, Auto control of various drives of cooling beds and bar shear areas along with appropriate interlocks based on mill operation logics.
The programs have been developed in modular manner. Separate modules have been written for individual control of various operations of drives like kick off, push off, shuffle bar eccentric, shuffle bar lifting, roller tables etc. PLC software gives the status of various equipments of the mill, which in turn gets displayed at HMIs. In addition to the PLC application program, HMI screens (One of the HMI Screen is shown in Figure 4/) were designed and software developed for monitoring the process status.
An improved comprehensive PLC based Automation system gives the instantaneous information at centralized location so that easy diagnosis and rectification of faults can be done. PLC based system enable easy and reliable implementation of control algorithm. The new control scheme further established that a fibre optic / Ethernet network-based system could be successfully implemented for critical control as well as monitoring applications provided the design is robust and all safety interlocks are considered.
The various features incorporated in the system for monitoring and control cooling beds and bar shears drives have resulted in a lowering of mill downtime and helped the central supervision and control the entire cooling beds and bar shears area.
This has resulted in instant faults diagnostics, troubleshooting, a reduction in mill downtime.
System commissioning involved shutdown related activities as well as jobs not requiring shutdown. Detailed field design and engineering was carried out in advance and micro plan prepared to enable smooth commissioning. Total commissioning was carried out in different phases. All jobs not requiring shutdowns such as PLC configuration, network testing, HMI testing etc. were completed in advance. Since the controls involved running the equipments of cooling beds and bar shears area in Auto mode as well as replacement of old interlocks, the final change over to the new system was carried out in phase wise manner taking the two/ three control drives of cooling bed and bar shears during weekly shutdowns.
Extensive trials were carried out off–line as well as on-line during mill operation. Each and every mechanism, where interlocks are used, required lot of trials so that the new system runs trouble free and safely.
The implemented system yielded benefits in terms of reduction in electrical downtime, reduction in cobble generation, and increase in mill availability. The drastic reduction in control cables from bar shear and Control Pulpit -10 areas has simplified the system as a whole. The scheme has resulted in faster diagnosis of faults and centralized control of the cooling beds and bar shear area of merchant mill. Evidently, the Cooling bed electrical delay has been reduced by 69 % on monthly average basis.
Similar schemes can be implemented in various areas where controls are either widely distributed or are relay logic based. The new system will have distinct advantages over the old one in terms of reliability, user friendliness and maintainability. The chances of unintentional errors will be less and any change in operation logic will be easy to implement through soft logic.
It is thus apparent from the above the present system for control and integration of various mechanisms of cooling beds and bar shear area of mill by using intelligent control desks establishes a network between the PLC and Intelligent Control Desk (Remote I/O integrated with Control Desk) through a communication cable. The single communication cable based operation of the present system results reduction in electrical down time and increase in Mill availability due to total elimination of huge bunches of long distance multi-core control cables running between Control Desk (without Remote I/O) and electrical control panels. Also the implementation of soft control logics in place of hard wired relay based logics facilitates the controlling the operation in cooling beds and bar shear area of mill.