FIELD OF INVENTION
The present invention relates to a data collection and control device (DCCD) for testing
performance of electrostatic precipitators (ESP) used for pollution control in thermal power
plants, cement plants, glass plants and steel plants. More particularly the present invention
relates to a data collection and control device for testing performance of electrostatic
precipitators for various simulated field conditions by collecting field level signals through
sensors, and controls and monitors the field equipment used in the electrostatic precipitator
performance test plant.
BACKGROUND OF THE INVENTION
Electrostatic precipitators (ESP) are configured with a number of fields, which have collecting
and emitting electrodes. A high electric field is generated between the electrodes to charge
the dust particles and collect the charged particles on the collecting electrodes. Collected dust
layer is dislodged using rapping mechanism with suitable hammers. High voltage is generated
by means of a high voltage transformer-rectifier. Rapping motors are used for operating the
hammers to remove the collected dust layer from the collecting electrodes.

Each field is provided with one high voltage transformer- rectifier and rapping motors for
collecting and emitting electrode rapping. The transformer-rectifier and rapping motor are
controlled and monitored by a micro-controller based controller, generally called ESP
controller. The ESP controller controls and monitors various electrical parameters like feedback
current, average voltage, peak voltage and valley voltage, alarm conditions of the high voltage
transformer-rectifier, primary signals, rapping motor on / off feedback, boiler load and opacity
input.
Performance of the electrostatic precipitators is decided by various factors like flue gas
temperature, moisture content, resistivity of ash, sulfur content etc., Electrical characteristics
of ESP varies with the above factors.
No specific prior art is found with application / method / or a common device to control and
monitor the entire plant for testing the performance of ESP.
In order to study and improve the performance of ESP for various field conditions like variation
in flue gas temperature, variation in flue gas moisture content, variation in flue gas oxygen
content, variation in ash content of coal etc. can be simulated and the performance of the ESP
tested or analyzed. A scaled down plant consisting of flue gas generator, a small ESP, fan,
chimney and electrical control systems is constructed for testing the performance of the ESP
with various simulated conditions.

Flue gas generator comprises hot air generator and ash feeding system which produces flue
gas with temperature from 120 to 150 degree C. Moisture content in flue gas is varied from 6
to 10 % with suitable control instruments. Oxygen content is varied from 4 to 6%. Impact of
variation in the specified range is verified by simulation. Fly ash from various power plants are
brought and flue gas is generated by mixing the fly ash with hot air, generated by hot air
generator.
Ash feeding system, hot air generator, three fields ESP and induced draft (ID) fan are the
major equipments used in the ESP performance testing plant. Each system is controlled by
respective electronics and they are integrated to a common control and data collecting system.
Various sensors like pressure, temperature sensor, oxygen sensor, moisture sensor are used
for measuring for further analysis. Signals from sensors, ESP controllers, ash feeding system,
hot air generator and ID fan are linked to a common controller for control and monitoring.
Temperature, oxygen content, moisture content and fly ash (for different resistivity) are varied
through the common controller and performance of the ESP is tested.

SUMMARY OF THE INVENTION
The main object of the present invention is to provide a data collection and control device
(DCCD) for control and monitoring of entire equipments of an ESP performance test plant. The
DCCD for ESP performance test plant of the present invention is provided with capability for
simulating field conditions in association with other mechanical equipments occurring in the
ESP interactively.
One more object of the invention is to provide a DCCD for ESP performance test plant, with
the adapted multiple hardware and software for enabling the process of simulation of field
conditions.
Another object of the invention is to provide a DCCD for ESP performance test plant, which is
capable of adapting multiple intelligent hardware (analog module and digital module) and
software for control and monitoring of field signals from the simulated field conditions of the
plant.
Further object of the invention is to propose a DCCD for ESP performance test plant, with
adapted multiple hardware and software enabling the process of measuring the field signals.

Another object of the invention is to provide a DCCD for ESP performance test plant, which
incorporates three intelligent processors for implementing automatic control and monitoring
the entire test plant.
Yet another object of the invention is to provide a DCCD for ESP performance test plant, which
incorporates implementing of graphical display of entire test plant with the help of supervisory
control and data acquisition (SCADA) method.
Still another object of the invention is to provide a device for control and monitoring of entire
test plant of electrostatic precipitator, which uses intelligent processor based modules and
methods to enable the simulation of the field conditions.
One more object of the invention is to provide a DCCD for ESP performance test plant capable
of graphical display of field signals for monitoring, graphical window for control of the entire
plant.
The device of the present invention comprises analog module, digital module, microprocessor
based ESP controller and industrial computer hardware with SCADA based MMI system and
provides the complete functionality to control, monitor and enable simulation for the entire
ESP test plant.

Thus, the present invention provides A data collection and control device (DCCD) for
controlling and monitoring performance of electrostatic precipitators (ESP) of a plant for
various simulated field conditions, comprising: an intelligent hardware module having an
intelligent analog module and an intelligent digital module for controlling and monitoring ESP
field signals; a microprocessor based ESP controller capable of communicating with said digital
module of said intelligent hardware module for enabling the ESP fields and for controlling and
monitoring the ESP operating parameters; and an industrial computer with a man-machine
interface (MMI) for controlling the analog and digital parameters at a single point control and
for creating a customized display screen for graphical display of the analog and digital
parameters and the ESP controllers.
In the present invention the DCCD system utilizes an intelligent analog module, which has the
facility of multiple input channels and multiple output channels. Each input channel can accept
field signals as 4 - 20 mA or 0 - 5 V or 0 - 10 V. Similarly each output channel can output
analog signal to field as 4 - 20 mA or 0 - 5 V or 0 - 10 V. The analog module has the facility
of communicating to a remote system, through MODBUS TCPIP over ethernet, or MODBUSOPC
over ethernet, signals like pressure, temperature, moisture content and opacity, for controlling
and monitoring through the analog module.

In the present invention the DCCD system utilizes a 32 bit processor based digital module,
which has the facility of 24 input channels and 24 output channels. The digital module can
accept field signals from potential free contacts as 24 V DC signal. Similarly it can output
digital signal to field by energizing relays. The digital module can communicate to a remote
system through controller area network (CAN) protocol over CAN communications bus. Signal
like hot air generator ON / OFF, ash feeding system ON / OFF and ID fan ON / OFF are
controlled and monitored through digital module.
ESP operating parameters are controlled and monitored by microprocessor based ESP
controllers. Status of operating parameters is transmitted to remote system over CAN
communication. The set parameters can be controlled locally or from remote system.
In the present invention the DCCD system utilizes an industrial computer with SCADA based
man machine interface (MMI) developed for single point control and monitoring of the entire
plant. The analog and digital modules are integrated with industrial computer through
communication. Analog module communicates over MODBUS-TCPIP (a communication
standard) over ethernet. Digital module and ESP controllers communicate over CAN
communication. The invention utilizes SCADA for creating customized display screens to
display analog, digital parameters and ESP controllers. Control windows are provided for
operator to control any analog or digital parameters.

Temperature of flue gas, oxygen content of the flue gas, moisture content of flue gas and ash
content of flue gas are varied using the field equipments and various test conditions are
simulated and the performance of ESP is verified by observing the opacity (outlet dust
emission level) signal. Lesser the opacity better the performance.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The invention can be described in detail with the help of the figures in accompanying
drawings, where
Fig. 1 shows in block diagram form the DCCD system of the present invention.
Fig. 2 shows in block diagram form the MMI system of the DCCD for
ESP performance test plant.
Figure 3 shows the analog connection to analog module of the DCCD system.
Figure 4 shows the digital connection to digital module of the DCCD.

DETAILED DESCRIPTION
According to the invention, the data collection and control device (DCCD) incorporates multiple
intelligent hardware components with man-machine interface (MMI) and relevant software.
The implementation is a common system for data collection and control of various parameters
for the ESP performance test plant.
It simulates various field conditions to carry out the test. A hardware block 11 as shown in
Fig. 1 includes an industrial computer 1, analog intelligent module 2, digital intelligent module
5, intelligent ESP controllers 8, controller area network (CAN), communication interface 9 and
supervisory control and data acquisition (SCADA) 10 based man machine interface (MMI) 17.
The analog intelligent module 2 consists of analog input module 4 and analog output module
3. The connection details for analog input and output module from field equipments are
shown in Figure 3. The analog input module 4 receives the analog signals from equipment like
ash feeding system 19, ID fan 20 and instruments like pressure sensors 21, temperature
sensors 22, moisture sensor 23, oxygen sensor 24 and opacity monitor 25. Hot air generator
18 receives user defined hot air temperature signal 26, user defined oxygen content of hot air
signal 27 and user defined moisture content of hot air signal 28 from analog output module 3.
Analog output module 3 sends control from ash feed rate 29 to the ash feeding system 19 to
vary the ash content in the flue gas. Also it sends the required fan speed 30 to ID fan 20.

The analog input module 4 receives field signals from pressure sensors 21, temperature
sensors 22, oxygen sensor 23, moisture sensor 24 and opacity monitor 25. Opacity monitor
25 measures the outlet dust emission from the plant. Opacity signal reflects the performance
of ESP. The analog input module 4 receives ash level signal 31 of the ash feeding system 19
and operating speed signal 32 of the ID fan 20.
Analog intelligent module 2 is connected to the industrial computer 1 with SCADA based MMI
system 17 through MODBUS TCPIP over Ethernet and controlled and monitored.
The digital intelligent module 5 consists of digital input module 7 and digital output module 6.
The connection details for analog input and output module from field equipments are shown in
Figure 4. The digital input module 7 receives ON / OFF signals 41, 42 and 43 from ash
feeding system 19, ID fan 20 and hot air generator 18 respectively. Ash level low alarm signal
44 from ash feeding system 19 is received by input module 7.
The digital output module 6 implements the ON / OFF command signals 38, 39 and 40 from
hot air generator 18, ash feeding system 19 and ID fan 20.
Digital intelligent module 5 is connected to the industrial computer 1 with SCADA based MMI
system 17 through controller area network (CAN) communication bus for control and
monitoring.

The intelligent ESP controller 8 energies the fields of ESP and enables the dust collection from
the flue gas. Generally it operates in local or remote mode of operation. It transmits the
operating status and receives the set parameters to and from remote system when it is
operated in remote mode. The ESP controllers are connected to the remote system through
controller area network (CAN) communication bus. Its operating parameters are set current,
high voltage transformer rectifier ON / OFF, operating current, operating kV and alarm status.
The MMI system 17 was developed using SCADA 10 which runs on industrial computer on
windows operating system. The MMI system 17 on industrial computer 1, monitors and
controls the analog intelligent module 2 digital intelligent module 5 and intelligent ESP
controllers 8. The MMI system 17 interacts with intelligent modules through various
communication bus.
The MMI system 17 for the test plant is shown in Figure 2, which comprises a main block 12,
analog signal handling block 13, digital signal handling block 14, ESP controller handling block
15 and interlock logic handling block 16.
The main block 12 configures and establishes connection between analog intelligent module 2,
digital intelligent module 5 and intelligent ESP controllers 8 and constructs various display
screens to view and user interface to set required command.

Analog signal handling block 13 reads the analog data from field equipments like hot air
generator 18, ash feeding system 19 and ID fan 20 through analog intelligent module 2. The
analog data like flue gas temperature, oxygen content, moisture content etc are read and
processed (converting from raw data to engineering value) for displaying in the respective
display screen. The set parameter like required flue gas temperature, oxygen content
moisture content etc are processed for sending it over communication.
Digital signal handling block 14 reads digital data from field equipments through digital input
module. It verifies the ON / OFF sequence and energize the alarm conditions. Any field
equipment is switched ON / OFF from the user interface this software block checks for the
interlock conditions and implements the command and annunciates the error conditions.
ESP controller handling block 15 controls and monitor communication healthiness of ESP
controllers and operating parameters. User set command like set current, high voltage
rectifier ON / OFF is sent from ESP controller handler.
Interlock logic handling block 16 monitors ON / OFF status of field equipments like hot air
generator 18, ash feeding system 19 and ID fan 20 and implements sequential ON or
sequential OFF as per the requirement.
The complete hardware 11 and the MMI system 17 of the DCCD provides facility to test the
performance of the ESP for various simulated field conditions.

WE CLAIM
1. A data collection and control device (DCCD) for controlling and monitoring performance
of electrostatic precipitators (ESP) of a plant for various simulated field conditions,
comprising:
an intelligent hardware module having an intelligent analog module and an intelligent
digital module for controlling and monitoring ESP field signals;
a microprocessor based ESP controller capable of communicating with said digital module
of said intelligent hardware module for enabling the ESP fields and for controlling and
monitoring the ESP operating parameters; and
an industrial computer with a man-machine interface (MMI) for controlling the analog and
digital parameters at a single point control and for creating a customized display screen
for graphical display of the analog and digital parameters and the ESP controllers.
2. The device as claimed in claim 1, wherein said intelligent analog module comprises an
input module capable of receiving multiple field signals as 4 to 20 mA or 0 to 5 V or 0 to
10 V, and an output module for outputting to fields multiple analog signals as 4 to 20 mA
or 0 to 5 V or 0 to 10 V.

3. The device as claimed in claims 1 or 2, wherein said intelligent analog module is capable of
communicating to a remote system, through MODBUS TCIP or MODBUS OPC over
Ethernet, signals like pressure, temperature, moisture content and opacity, for controlling
and monitoring through said analog module.
4. The device as claimed in claim 1, wherein said intelligent digital module is a 32 bit
processor provided with digital input and output modules, wherein said digital input
module is capable of receiving signals from potential free contacts as 24 V DC signal, and
said digital output module is capable of outputting digital signal to field by energizing
relays.
5. The device as claimed in claim 4, wherein said digital module is capable of communicating
with a remote system through control area network (CAN) protocol over CAN
communications bus, for controlling and monitoring signals like hot air generator ON /
OFF, ash feeding system ON / OFF and ID fan ON / OFF.
6. The device as claimed in claim 1, wherein said microprocessor based ESP controllers are
connected to a remote system when operating in a remote mode for communicating with
the help of a CAN communication interface for transmitting to and receiving from the
remote system operating status and set parameters respectively.

7. The device as claimed in claim 1, wherein said analog module, said digital module and said
ESP controllers are integrated with said industrial computer through communication.
8. The device as claimed in claim 7, wherein said analog module is capable of communicating
with MMI of said industrial computer over MODBUS-TCIP.
9. The device as claimed in claim 7, wherein said digital module and said ESP controllers are
capable of communicating with said MMI of said industrial computer a can communication
interface.
10. A data collection and control device (DCCD) for controlling and monitoring performance
of electrostatic precipitators (ESP) of a plant for various simulated field conditions,
substantially as herein described and illustrated in the figures of the accompanying
drawings.

The main object of the present invention is to provide a data collection and control device
(DCCD) for control and monitoring of entire equipments of an ESP performance test plant. The
DCCD for ESP performance test plant of the present invention is provided with capability for
simulating field conditions in association with other mechanical equipments occurring in the
ESP interactively.