Aist gallo

Abstract

Web-based data gathering, automatic reporting and schedule generation for coke plant automation.

This web-based application automatically collects all the relevant data from the field and automatically generates production, process, quality and EPA reports. The system includes wireless portable devices that allow the environmental inspectors to collect data directly in the field. The web-based eVision technology requires no additional licensing costs for increasing users or adding variables to the system. This complete data acquisition system combined with local HMIs has given each operator access to an interactive, automatically generated schedule, and thus virtually eliminates erroneous data entry, and wasteful storage of paper records.

The authors are: Marcos Gallo Joaquin Veiras Javier Barreiro Edgardo La Bruna 1. Overview The main parts of the system are: • Operation data collection and reporting.

• Schedule generation, editing and viewing.

• MAC data collection and reporting.

• Plant parameters acquisition and reporting.

2. Operation data collection and reporting 2.1.1. Data collection This module of the system collects the main operation parameters such as: • ID of pushed / charged oven • ID of battery • ID of pusher / larry car • Duration and start date / time of every push / charge • Weight of the charged coal • Amperage of the pusher’s motor • Oven ID and start date / time of coal leveling after charge Parameter data originates in the PLC and in a touch screen Panel PC (PPC) of each car. The following diagram shows the data flow for one of the cars:

Figure 1 - Operations data flow (one car)

Data is collected directly from the push and larry cars using PLCs. Each of these PLCs is connected to a small iVision scada through an OPC server that runs on a PPC that sits in the operator’s cabin. This local iVision is used to provide communication between the PLC tags and the HMI application running on the PPC. Another larger iVision is running on the IV_SERVER, this iVision connects to local OPC server that gathers data from the PLCs in the cars through the wireless network. A tracking program, which runs on the server, collects all this data and stores it into a database.

In case the wireless link fails or there is a problem in the data transmission, each car has a backup system, the data from the charges / pushes that couldn’t be recorded by the server are stored in the PPC until connection is restored. At this moment, each car sends the compressed data to the server so it can be processed.

The weight of the larry cars are measured by Ethernet scales which are connected to the iVision server through the corporative LAN. A service application runs on the server to read the weights, stores them in iVision tag and generates the corresponding events so that the tracking program can record the weights in the database.

Figure 2 – Operation network connections diagram

The PPC on each car runs an application that provides the operator of the car all the information regarding the daily operation. There are two different applications, one for the pusher cars and one for the larry cars.

Some of the pusher and larry application screens follow:

Figure 3 - Main Operation Screen

Figure 4 - Oven Selection Screen

Figure 5 - Schedule View Screen

Figure 6 – Motor ram current curves

These applications have been designed for accessibility, taking into account that the only available interface with the user is the PPC touch-screen. The PPCs show among other information: the oven to be pushed / charged next, according to the schedule; the time left to push / charge the next oven; the complete schedule and the ram motor current trend for previous pushes. It also permits the operator to iterate through all the ovens in the schedule to select an oven other than the current one, or to select an oven that is not scheduled. This is helpful in cases where one of the cars goes out of service and another car can perform the missing pushes / charges.

2.2. Operation data reporting Pushes, charges and operation reports are automatically created by eVision based on the information gathered by the tracking system.

The main operation reports generated by the system are the following: • Pushers operations: shows all the pushes done by the cars. It is possible to filter by date, shift, battery and pusher car. Also, from this screen it is possible to access the push editor, which allows changing all the parameters associated with a determined push, including the Oven ID.

• Larry operations: similar to “Pushes operations” reports, only that shows all the charges done by the cars.

• Pushes currents: shows the current curves for the same oven over a period of time. It also shows max and avg. curve of the ram motor current. This report permits predicting the behavior of an oven, avoiding costly break downs. As is shown in figure 8, the system overlaps in the same graphics the AMPS for several cycles of the same oven. It is a great help in tracking the oven walls status and also when a new coal mix is used. This report can also show all the maximum amps (peak in the push) and the average current for a certain period of time for the same oven, and superpose in the same graphic when a coal mix was changed.

• Shift / Day / Month / Year operations: shows the number of pushes, charges, total coal weight loaded, max. Pushers ram motor current, max and min charging-pushing times and min-avg-max cooking times.

Figure 7 - Pusher - Larry operations report

Figure 8 - Pushers currents report

Figure 9 - Pushes - Charges editor

Figure 10 - Shift/day/month/year operation report

3. Schedule generation To reduce paperwork, record storage and unwanted errors, schedules are generated automatically by the system based on the previous operation of the plant or by following a predefined push pattern.

The schedules are generated in eVision and then transmitted automatically to each car. If the daily schedule is modified, the changes are instantly reflected in the cars.

A more detailed diagram of the schedule generation – consumption cycle, is shown next:

Figure 11 - Schedule cycle

All the generated schedules are stored in the database as historic for future usage, such as comparing the actual operation of the cars with the schedule issued.

Since it is a web based system anyone connected to the plant’s network, with the correspondent authorization, can generate, modify or view the schedules.

For automatic generation based on operation, the system checks all the ovens that are currently charged, available to be pushed (e.g. Not in maintenance) and with the specified cooking time elapsed, and presents them to the supervisor to modify before saving it.

Some of the schedule generation, edition and viewing screens are the following:

Figure 12 - Schedule generation / editor

Figure 13 - Schedule viewer

4. MAC data collection and reporting Data for the MAC reports comes from several sources, the main ones are: • Fumes inspectors • Opacity monitors in the battery stack • Battery bag house and scrubber 4.1.1. Fumes inspector In order to perform the inspections easily and fast, the inspectors are provided with rugged TabletPCs that have a touch-sensitive screen.

These TabletPC’s run an application that allows performing the inspections offline and then uploading all the data to the eVision server.

Some of the TabletPC application screens are the following:

Figure 14 - Main application Screen

Figure 15 - Charging Inspection Data Entry

Figure 16 - Charging Inspection details

Figure 17 - Pushing Inspection background

Several days of inspections can be stored in the TabletPC’s until they’re downloaded. Inspectors can edit previous inspections in case they detect an error.

The data collected by the application is used by eVision to generate the corresponding NESHAP and SIP reports.

4.1.2. Opacity monitors All the data from the opacity server, which collects the fume opacity values from the batteries stacks, is transmitted to the iVision Server. This data is read by a program and written to several iVision tags in order to save their values for later viewing. Also, the program writes the opacity values to the eVision database so it can generate the corresponding reports.

Anyone connected to the plant’s network can view the trending of the opacity values through the iVision Trender application, allowing a fast and easy detection of any problem related with the push of any oven.

4.1.3. Battery bag house and scrubber The bag house and scrubber Level 1 network is connected to a PLC that transmit’s all the parameter values to the iVision server so it can be recorded by the tracking program into the eVision database.

Any user can also check the historic and real time values of these parameters trough the iVision Trender application.

Some of the trending shown by the iVision Trender application is the following:

Figure 18 – Scrubber variables trend

Figure 19 – Opacity monitors trend

The data from all these sources is used to generate MAC reports as required by the federal government. These reports are: • Pushing inspection • Charging inspection • Batteries top side inspection • Oven door inspection • Batteries main collector inspection • Performance evaluation • SIP standard daily emissions • NESHAP standard daily emissions • Days left until next inspection for each oven The following images show some of the reports mentioned above:

Figure 20 - Main application Screen

Figure 21 - Charging Inspection Data Entry

Figure 22 - Main application Screen

Figure 23 - Main application Screen

5. Plant parameters acquisition and reporting The system reads diverse plant parameters in order to improve gas consumption and battery performance.

The main parameters read by the system are: • Main fuel gas flow • Waste Heat • Stack pressure • Gas pressure • Charging steam pressure To read this data PLCs are connected to the existing measuring devices in the reverse room of each battery. These PLC are connected to the iVision server.

In addition of the standard reports, eVision provides a web mimic for all batteries.

These mimics show the operation of the batteries and its main parameters in real time, allowing a fast monitoring of the plant in general without the need to physically go to the field.

The following images show the battery mimics of the system:

Figure 24 – Battery operation and parameters

Figure 25 – Complete battery parameters

6. Conclusion The exposed system covers the most important aspects of the operation, maintenance and environmental control of a coke processing plant; aiding in the monitoring and troubleshooting of diverse problems. At the same time it reduces and simplifies all the paper work, this translates into a direct reduction of human errors and increase of productivity.

Since it is a web-based system, it allows propagating all the plant’s critical information across all levels of personnel, augmenting the common knowledge and in this way reducing the response time should any problem arise.