FIELD OF THE INVENTION.
This invention relates to an automatic coke moisture measurement system to
reduce the moisture determination time.
PRIOR ART.
Moisture content is an important parameter in many industrial and mining
processes. This applies across the complete range of processing. The iron
making process is a typical example of the requirement for accurate moisture
treatment Traditional methods of moisture determination using sampling
and laboratory techniques requires about 2 to 3 hours time which is
inadequate for process control requirement
Because of high permitivity of water, the dielelectric properties of moist
materials are influenced at the micro wave range. The heating by
microwave energy is based on excitation of a molecular dtpole at its
resonant frequency at 2, 45 Ghz near the resonant rotational frequency of a
liquid water molecule. The electric field changes direction at 4.9 Billion
times/sec, causing oscillations of the molecules at he same rate. This rapidly
alternating electric field exerts a torque on the molecule whose resulting
violent motion results in instant heating.
Moisture measurement methods used at present in testing laboratories are
based on drying the sample in an air oven at the temperature of about 200°C
for at least two hours. This method requires manual operation in weighing
and drying the sample and determining the moisture content by difference
in weight
OBJECTS OF THE INVENTION.
An object of this invention is to propose an automatic coke moisture
measurement system which reduces the time for determination of total
moisture.
Still another object of this invention is to propose an automatic coke
moisture measurement system which completely eliminates the operator
deciding the weight of sample.
Yet another object of this invention is to propose an automatic coke moisture
measurement system which eliminates the decision of operator about the
period of heating the sample inside a microwave oven.
A further object of this invention is to propose an automatic coke moisture
measurement system wherein no skilled worker is required.
Further objects and advantages of the invention will be more apparent from
the ensuing description.
According to the invention there is provided an automatic coke moisture
measurement system to reduce the moisture determination time comprising a
sample processing means; a robotic moisture analyzer means; a micro oven ;
and a PLC-based controller , the sample processing means having a roller
crusher to crush the raw coke into plurality sizes of samples; the robotic
moisture analyzer means connected to the sample processing means via a
flat conveyor to receive a pre-determined quantity of coke sample
comprising a manipulator to handle the sample, a trolley with electronic
balance to determine the weight of the sample, and a container; the micro
oven receives the container with the sample being shifted by means of the
manipulator for heating the heating time being monitored and controlled by
the PLC-based controller , the container with the heated sample being re-
weighed at the trolley balance , the weighing data is transmitted to the PLC-
based controller which calculates and measure the moisture-content in the
sample for display on a PC .
BRIEF DESCRIPTION OF THE INVENTION WITH REFERENCE
TO ACCOMPANYING DRAWINGS.
The automatic coke moisture measurement system of the present invention
operates as a computer assisted moisture determination system using robotic
technique and microwave heating. A robotic moisture analyzer means takes
control of the sample after it is charged into the dosing screw feeder. The
positional data is transmitted by the proximity sensors to PLC which runs
the process in a sequence as per the process requirement The command to
the PLC is given through the MMI in PC located at PC Workstation. The
complete data on total moisture content is displayed on the PC screen and
can be transmitted to the concerned department (customer).
The system has four major functional areas. These are:
1. Sample Processing means as shown in Fig. 1;
2. Robotic Moisture Analyser means as shown in Fig. 1;
3. Operator's Interface as shown in Fig. 2;
4. Input/Output Control;
5. System Cabling and Accessories.
SAMPLE PROCESSING MEANS.
It consists of roll crusher 1 and double deck vibratory screen 2. Both the
units axe switched on to run the machines and get the required sample size.
The sample (required to be processed to size 10-15 mm ) is charged into the
hopper 3 of roller crusher 1. It crushes complete sample and discharges
them on the double deck vibratory screen 2 placed below the roll crusher.
Alter passing through the double deck vibratory screen 2, the samples are
collected in three sizes, i.e. samples above 15 mm size, samples above
10mm and below 15 mm sizes and samples below 10mm sizes. Higher size
samples are re-charged to the hopper (3) with the help of a bucket elevator
ROBOTIC MOISTURE ANALYSER MEANS.
This means consists of dosing screw feeder 4 for feeding the required
quantity of sample, manipulator 5 to handle the sample and trolley with
electronic balance (8) for receiving and weighing the sample. It starts
operation after switching on a push button which gets the command from a
PLC (18) in the control room at a distant location. All the relevant details of
the sample are entered in the PC (14) before giving the command to the
RMA (17). The trolley with electronic balance (7) having a containcr(6)
moves forward and comes to the required position to receive the sample.
The dosing screw feeder 4 starts operation of delivering the crushed sample
in the size range. The container (6) receives the sample and the dosing
screw feeder (4) stops operation after the system has received the required
amount of sample. At this point, the manipulator 5 takes over and lifts the
container 6, opens the door of microwave oven 7, places the container inside
the oven, closes the door and heating starts. The heating continues for a
period monitored by the PLC (18). The door of the microwave oven 7 opens
automatically after heating the sample. The manipulator's arm (5) brings
back the sample on the electronic balance to determine the difference in
weight. The difference in weight is automatically transmitted to the PLC
(18), which calculates, and displays the moisture content The
manipulator's arm (5) rotates to drop the burnt sample and discharges the
left over sample in the dosing screw feeder (4) out of the system. After the
trolley (8) retracts to home position, the system becomes ready for next run.
The complete system is driven pneumatically. The sample processing means
and the Robotic moisture analyzer means are interconnected by a flat
conveyor (10) to maintain the system integrity.
The operator interface consists of a PC (13) and push button to start the
system. The PC (13) increases the flexibility of the system. If at any point
of time the operator wants to change the system's decision, he can do so by
pressing an EMERGENCY button and/or resetting the system. The system
will start from the same point where it has stopped after release of the
EMERGENCY button. After resetting the system, all the components go
back to HOME position.
The hardware block diagram has been shown in Fig. 2.
SOFTWARE FLOW.
1. Feedback processing hardware is initialized.
2. Set-up is kept prepared for receiving the feed back signal to PLC.
3. System waits for the feed back signal in HOME position of all the
components.
4. MMI transform ail the data to PC.
5. Waits for the operator filling the relevant fields in the menu.
6. Transmits the date to push button at site through PLC.
7. Allows the system to run in sequence as per ladder logic.
8. Completes the task.
9. System returns to HOME position.
1. Ad automatic coke moisture measurement system to reduce the
moisture determination time comprising a sample processing means; a
robotic moisture analyzer means; a micro oven (7); and a PLC-based
controller (18), the sample processing means having a roller crusher
(1) to crush the raw coke into plurality sizes of samples; the robotic
moisture analyzer means connected to the sample processing means
via a flat conveyor (10) to receive a pre-determined quantity of coke
sample comprising a manipulator(5) to handle the sample, a trolley
with electronic balance (8) to determine the weight of the sample, and
a container (6); the micro oven(7) receives the container(7) with the
sample being shifted by means of the manipulator(5) for heating, the
heating time being monitored and controlled by the PLC-based
controller (18), the container(6) with the heated sample being re-
weighed at the trolley balance (5), the weighing data is transmitted to
the PLC-based controller (18) which calculates and measure the
moisture-content in the sample for display on a PC (14).
2. The system as claimed in claim 1, wherein the sample processing
means further comprises a hopper (3), and a double deck vibratory
screen (2) disposed below the roller cruster(l), and wherein the
hopper (3) receives the sample for transmitting to the roller crusher
(1), and the double deck vibratory screen (2) segregates the crushed
coke into plurality of sample sizes.
3. The system as claimed in claim 1, wherein the robotic moisture
analyzer means further comprises a dosing screw feeder (4) receiving
the sample from the sample processing means via said flat conveyor
(10).
4. The system as claimed in claim 1, wherein the sample processing
means has a bucket elevator (9) for redirecting crushed coke
unsuitable for sampling to the hopper (3).
5. The system as claimed in claim 1, wherein the PLC-based controller
(18) is located at a distance and communicates via. operators'
interface.
6. An automatic coke moisture measurement system to reduce the
moisture determination time as herein described and illustrated with
reference to the accompanying drawings.

An automatic moisture analyer comprising a sample processing means (1 to 4, 9,
10); a robotic moisture analyzers (5 to 7, 8); a micro oven (7) and a PLC base
controller (18). The sample processing means having a roller crasher (1) to crush
the raw coke into various sizes; The robotic moisture analyser means connected to
the sample processing means via a flat conveyor (10) to receive a pre-determined
quality of coke sample comprising a manipulator (5) to handle sample, a trolley
with electronic balance (8) to determine the weight of the sample and a container
(6); the micro oven (7) receives the container (6) with the sample being shifted by
means of manipulator (8) to heating. The heating time being monitored and
controlled by the PLC based controller (18), the container (6) with the heated
sample being re-weighted at the trolley balance (5), the weighting data is
transmitted to the PLC based controller (18) which calculates and measure the
moisture content in the sample for display on a PC (14).