What is the minimum required amplification gain?

Students are required to develop the instrumentation and control for the cement ball mill grinding
unit and separator as described below and shown in figure 1.
Ensure that all the requirements of the measuring instruments for the cement ball mill grinding
unit, variable speed fan, dynamic separators, valves and signal transmission system are covered.
Process Plant Description:
• The clinker formed from the pyro-cooler section is stored in a Silo. The Silo is a large storing
device for handling bulk solids.
• In the cement ball mill grinding system, the input materials are clinker, gypsum, fly ash
(depending on the type of cement to be produced) and additives.
• Assume that they are producing Pozzolana Portland Cement (PPC), in which fly-ash is used
• For ordinary Portland cement (OPC), fly ash is not used.
• In the PPC type cement, the input materials Clinker, Gypsum, and fly ash have a gravity feed
into the weigh feeder. The values of these inputs are in Tons per Hour (TPH). The weigh
feeder is a transporting device. These materials are then collected in a bin that has a
controlling gate to adjust the level of the bin.
• The level of the bin is to be maintained at around 15%. The controlling gate operates within
0-100%.
• The materials from the bin are fed into the ball mill for grinding. The ball mill is filled with
ball bearings for crushing the materials. The ball mill is in constant rotation and the materials are crushed inside. The fine materials output from the ball mill goes to the bucket
elevator which is located at the mill outlet.
• The ball mill material temperature at the outlet is controlled by a water pump system.
Normal outlet material temperature is maintained at around 1100C. There would be two
water pumps where one is operating, and the other pump is in standby mode. The water
pump is operated between 0 and 100%.
• The Bucket elevator at the mill outlet carries the ground material and feeds into a dynamic
separator. The purpose of the separator is to separate fine material from coarse material.
The fine material is lifted from the top of the separator and the coarse material is pushed to
the bottom of the separator. There would be a tripping value for the bucket elevator
current. So that the maximum bucket elevator current is 120 Amps.
• The dynamic separator circuit is connected to the mill fan and a damper to control the
airflow to the system. The speed of the separator fan can be varied according to the
fineness of the material required. The fineness is measured using Blaine’s test in the
laboratory. The higher the separator speed, the finer the product collected. This fine
material is transported by air slide to the product silo.
• The rejects (coarse material) from the separator are fed back to the mill inlet for further
grinding. A bag house is connected to the mill outlet to collect any fine material that is
carried along with the dust.
• The fine material collected at the baghouse is then sent along an air slide to the product silo.
Compile a project report of approximately 3,000 words (excluding figures and tables). When
compiling your report, we recommend that you read the suggestions listed below and implement
them in your report.
1. Analyse the process requirements. (10 marks)
2. Describe the control philosophy for each control loop and propose adapted measurement
devices and Data Acquisition System. Justify your choices. (15 marks)
3. Produce a complete Piping and Instrumentation Diagram and Instrumentation Index for the
process including signal transmission. Denote the instruments in the figures as per the
Instrumentation standards ISA 5.1. (15 marks)
4. List brief guidelines for factory tests, site tests and pre-commissioning checks and required
Calibration and Safety audits. (5 marks)
5. A Type B, continuous thermocouple (0-1700°?), is connected to a YTA510 wireless TT for
temperature measurement of the ball mill. The ambient temperature of the plant location is
always above zero. The voltage thermocouple returns are between 0 to 12.433 mV. To
detect a change of 0.3352 ??, propose the best DAQ, either 12-bit or 16 bits, for this
project.
The range voltage of the devices is either 0 to 5 V or -5 to 5 V. Please explain which one is
more suitable for the project.
The amplification list is shown as follows:
Amplification gain: 135, 210, 215, 225, 250,355, 395, 405.
What is the maximum possible amplification gain? (Justify your reason). (5 marks)
What is the minimum required amplification gain? (Justify your reason). (5 marks)
Which one is the best resolution, 12-bit, 16-bit, or both? (Justify your reason). (5 marks)
6. List the documentation needs – Drawings, Index, Data Sheets, Calibration certificates, Audit
reports and operating procedures. (5 marks)
7. Discuss possible future enhancements such as remote monitoring and energy savings.
(10 marks)
8. Communication style and clarity of the report. (5 marks)
Important notes to students:
• This is a report-style assessment based on research, which means students must reference
any statement or idea which have been borrowed from technical and scientific papers and
books.
• Acceptable reference style is IEEE.
• Copy and paste and high rate of similarity (even with reference) is considered as plagiarism
and will be dealt with in accordance with EIT rules.