Control Lab Repair and Lab Experiment Design

Jennifer Pratt

Senior Lab Experience

December 6, 2006

Overview

Overall Goals Objectives Introduction Description of Process Challenges Work done on rig Deliverables

Overall Goals

Learn about process control Establish a lab for future Process control

classes to utilize Repair the temperature rig Gain lab experience

Objectives

Replace hoses, flow sensors, and flow transmitters

Perform all practicals in lab manual Make sure the rig runs properly while doing

practicals Prepare the lab experiment guidelines Troubleshoot problems with the rig and

experiments Prepare a repair/maintenance manual for the

rig operations

Timeline

Introduction Temperature control rig built by

Feedback Discovery Products

Figure 1: TPR

Introduction

Basic understanding of BPR, process controller, and process interface required

TPR consists of primary and secondary flow Secondary flow provided by BPR Primary flow cycles through heat exchanger

while secondary flow cools it Practicals focus on familiarization of different

types of control No data collected as in traditional

experiments

Introduction

Lab demonstrates key concepts of control such as: On/Off control Manual/Automatic control P-Pi-PID Control Modeling Dynamic Systems Mimic Diagrams Ratio Control/Dual Loop Control

Description of Process

ReservoirHt. Exch

Pump

Radiator

Header Tank

Flow sensor

Flow Sensor

Figure 2: TPR

Description of Process

Figure 3: TPR + BPRSecondary Flow In

Secondary Flow Out

Project Challenges

Broken parts Mishandling of rig Cleaning entire piping system Sharing BPR with control labs every other week Ordering parts Recent PI communication problems with BPR T.A. slow in response to requests for help

Work Done

Drained old water from system/refilled with distilled Cleaned and replaced 2 flow sensors Ordered and replaced 2 new pulse flow transmitters

and 2 new flow sensors Kept log of repair attempts and successful

techniques Performed all practicals in lab manual Created a student lab companion for completing

practicals Created a repair/maintenance manual

The Practicals

6 Assignments with 3-4 practicals each Assignment #1- Initialization of Rig Assignment #2- Familiarization of the Rig Assignment #3- Manual Flow Control Assignment #4- Temperature Process Control Assignment #5- P-PI-PID Temperature Control Assignment #6- Complex Control Loops

Issues Found in Practicals

Assignment 1 Practical 3- Questions are misprinted in student lab manual

Assignment 3 Practical 2- Patching diagram is mislabeled Practical 3- Additional patching information is included in

background but not in patching section Assignment 4

Practical 1- Additional patching information is included in background but not in patching section

Practical 2- Patching diagram is mislabeled Assignment 5

Practical 2- Questions are misprinted in student lab manual

The Student Lab Companion

Includes introduction with advice on how to approach labs

Lists questions to be answered after performing each practical

Gives helpful hints for answering tough questions

Gives additional info not provided in lab manual

Lists mistakes found in each practical

An Excerpt from the Companion

Assignment 5: Practical 1 Flow ratio is demonstrated by changing secondary flow set point and

observing the corresponding change in primary flow Questions

Explain with the aid of the diagram below, a system for automatically proportioning the flow of liquid in two separate pipelines.**

**Answer Provided in Instructor Lab Manual

Repair/Maintenance Manual Guidelines The rig should only be used with distilled water to prevent

buildup of lime and calcium on the inside of the pipes, sensors, and heat exchanger.

The rig should be handled carefully and expertly so that parts are not damaged during disassembling/assembling.

There are certain ways that components must be removed and replaced so that they function properly and are not damaged.

Maintenance should be completed as scheduled to ensure the proper functioning of the process rig for future classes to benefit from.

Ordering of new parts from Feedback Inc. is a lengthy expensive process, so great care should be taken when handling them.

Instructions Given in Manual

Removal of flow sensors from the rig Cleaning of the flow sensors Repair of flow sensor electrical components Replacement of flow sensors back on the rig Draining/Refilling of the water in the rig Troubleshooting with flow/temperature transmitters Maintenance of hose piping between BPR and TPR Scheduled Maintenance

Repair Log Example

Hose replacement

Date Performed By Date Performed By

09/06 J. Pratt

Conclusions/Recommendations

Rig should be cared for and cleaned properly Labs will be easier for future students now

that mistakes have been pointed out Use the repair manual on a regular basis Use the student lab companion questions for

the next control class (Fall 2007)

Questions?