Session 03 - Agenda Activity Est. Time, min 1. Agenda 2. Learning Objectives - Level 3. Introduction to Level 4. Level Measuring Instruments 5. Level Measuring Instruments (continued) 6. Level, Temperature, Density and Volume 7. Learning Objectives - Flow 8. Introduction to Flow/Terms 9. Flow Sensing/Measurement Instruments BREAK 10. HWAs and Class activity Instrumentation I - Session 3

Process Control Instrumentation. To measure the process variables and control process variables. Indicater, sensors, transmitters, controller and final control element Instrumentation I - Session 3

Most Common Control Elements Instrumentation I - Session 3

Chapter 4 – Objectives (page 1) 1. Define terms associated with level and level instruments: level ullage (outage) inage direct/indirect measurement interface level meniscus density hydrostatic head pressure Instrumentation I - Session 3

Chapter 4 – Objectives (page 2) 2. Identify the most common types of level-sensing/measuring devices used in the process industry: gauge/sight glass float tape gauge differential pressure cell bubbler displacer ultrasonic device nuclear device 3. Describe the purpose and operation of various types of level-sensing/measuring devices. 4. Describe the relationship between temperature and level control as it relates to the density of liquid. 5. Describe the relationship between temperature and level control as it relates to the volume of a liquid. Instrumentation I - Session 3

Level? Level is the position of the surface of a liquid in a container as compared to a reference point. H is the distance from a zero reference point to the surface of the material. Depth is a distance measurement from the surface of the liquid that extends downwards.(feet/inches). Instrumentation I - Session 3

Percent Level Measurement, Ullage(Outage) and Inage Innage : the measurement from the bottom of a tank to the surface of the liquid. Outage means measuring from the surface of the product to the top of the tank. The most common way to indicate the level of a tank is by percent level measurement. Instrumentation I - Session 3

Point and Continuous Level Measurement Where level is measured at one distinct point in a tank to establish high and low level alarm points. Continuous level measurements: used to monitor all level points in the tank from zero percent at the bottom of the measuring device to 100 percent full. Instrumentation I - Session 3

Direct and Indirect Level Measurement Measures level interms of level. Indirect level measurements measures level in terms of another process variable such as head pressure or weight. Instrumentation I - Session 3

Interface The common boundary or plane between two immiscible liquids is called an interface level. Instrumentation I - Session 3

Separator www.emersonprocessxperts.com The lighter liquid spills over a weir which is like a holding plate into a separate compartment for removal while the heavier liquid is removed in front of the weir through a pipe connected to the bottom of the tank. Instrumentation I - Session 3 www.emersonprocessxperts.com

Meniscus In a concave shape, Meniscus is the curved upper surface of a column of liquid. Instrumentation I - Session 3

Liquid Head Pressure P=h*sg Instrumentation I - Session 3

Gauge/Sight Glass: Tubular Type They operate just like u-tube manometers. If they have an equal pressure applied to both sides, their levels are the same. Since gravity applies equally to both sides if the height of the liquid is greater on one side, the height naturally adjusts by moving liquid between the two chambers. It has a clear glass tube and is open into a vessel on the top and bottom. Instrumentation I - Session 3

Gauge/Sight Glass: Flat Glass Level Gauges They are designed with heavy bodies and thick glass to promote safety in high temperature and high pressure hydrocarbon services. Instrumentation I - Session 3

Float It is a level – sensing element that tracks the surface of a liquid by floating on it. They operate on two simple principles buoyancy and mechanical action. The float senses the surface and then a mechanism or transducer equates its position into a level measurement. The float can also actuate a control valve like a simple toilet bowl. Instrumentation I - Session 3

Tape/Tape Gauge A narrow calibrated strip or ribbon used to measure the length. A tape gauge is a level measuring device consisting of a metal tape that has one end attached to an indicator and the other end attached to a float. Continous level changes in a tank. Instrumentation I - Session 3

Differential Pressure (d/p) Cell/ Transmitter Instrumentation I - Session 3

Differential Pressure (d/p) Cell Instrumentation I - Session 3

Bubbler http://apcs.net.au/ A bubbler is a special kind of head pressure measuring method that allows us to measure the head pressure without the pressure sensor coming in contact with the process fluid. Corrosive? No direct contact of sensing device. Includes a purging gas source, pressure and flow regulating device, a pressure sensing device and an open ended tube called dip tube. Extended downward from the top of the tank. An inch or two above the bottom of the tank. A gas is supplied to this rotameter and can be controlled by the valve so that it flows very slowly down the tube and escapes out of the open end of the tube into the fluid creating bubbles. The pressure of the gas in the tube should be equal the total pressure exerted by the liquid at the end of the tube.diameter should be large enough. The other pressure device is connected to the dip tube providing a measurement of the back pressure. http://apcs.net.au/ Instrumentation I - Session 3

Displacer They are among the oldest level measuring devices in industry. a displacer is a sealed cylindrically shaped tube used to measure buoyancy which is defined as an upward force on a submerged body that is equal to the weight of the displaced fluid. Displacer, a means of measuring the apparent weight change of the displacer, and an indicating or transmitting component. The principle of its working stated that the buoyancy force exerted on the body of an object immersed in a fluid is equal to the weight of the displaced fluid. Instrumentation I - Session 3

Ultrasonic/Radar Device They emit a pulse of energy that is reflected off of the surface of the material back to the reciever. they can be two separate units a transmitter and a reciever or may be a single unit called a transponder Instrumentation I - Session 3

Nuclear Device Uses a tightly controlled gamma radiation source with a detector to infer a level in a tank. It is very dangerous. Should be handled very carefully. They located at outside of the tank. Instrumentation I - Session 3

Load Cell A load cell is a transducer used to measure force or weight. It includes a strain gauge bonded to a robust support column called a forced beam. This force beam is usually a piece of solid steel capable of supporting the entire weight of a vessel and its contents. As weight is applied to the load cell, a read out and/or transmitting device provides a corresponding output measurement. As weight is applied to the load cell, the associated strain gauges measure the deformity of the force beam. this produces a change in resistance that can be measured by an electronic circuit. This change in resistance can be correlated to a weight change and therefore a level change. Instrumentation I - Session 3

Level, Temperature, Density and Volume Temperature can affect the density of all matter. the physical manifestation of this phenomenon is that a fixed amount of matter experiencing an increase in temperature requires more room because its volume increases proportionally. Instrumentation I - Session 3

Chapter 5 – Objectives (page 1) 1. Define flow and terms associated with flow: fluids (gases and liquids) laminar turbulent 2. Define terms associated with flow measurement: direct and indirect flow measurement positive displacement flow measurement percent flow rate volumetric flow units mass flow units. Instrumentation I - Session 3

Chapter 5 – Objectives (page 2) 3. Identify the most common types of flow sensing/measuring devices used in the process industry: orifice plate venturi tube Flow nozzle pitot tube annubar tube rotameter electromagnetic meter (Magmeter) turbine meter mass flow meter 4. Describe the purpose and operation of flow sensing/measurement devices used in process industry. 5. Explain the difference between total volume flow, flow rate and volumetric flow. Instrumentation I - Session 3

Flow and Fluids Flow is a material in motion. Gases and liquids can flow from one point to another point depending on pressure and temperature. flow rate is a measure of how much fluid is flowing or moving through a pipe in a given period of time. Flow is a material in motion. Gases and liquids can flow from one point to another point depending on pressure and temperature. Liquids and gases are fluids. from a higher p to a lower p. Flow and flow rate have the same meaning in industry. The rate that a fluid flows is a measure of how much fluid is flowing or moving through a pipein a given period of time. Instrumentation I - Session 3

Laminar and Turbulent Flow When the path is smooth and without obstruction, the flow is called laminar because the molecules line out to a smooth flowing pattern. This type of movement is characteristic of long pipelines where the molecules have a chance to settle down and move in a more orderly fashion. (streamline flow). The velocity of the flowing fluid changes smoothly and equally from the pipe wall inward to the center of the pipe where the velocity is at its highest. Piping bends, corrosion, valves, or any other obstruction to the flow inside a line causes turbulence or turbulent flow. https://en.wikipedia.org/wiki/Laminar_flow Instrumentation I - Session 3

Laminar and Turbulent Flow The velocity of the flowing fluid changes smoothly and equally from the pipe wall inward to the center of the pipe where the velocity is at its highest. (streamline flow). The velocity of the flowing fluid changes smoothly and equally from the pipe wall inward to the center of the pipe where the velocity is at its highest. Piping bends, corrosion, valves, or any other obstruction to the flow inside a line causes turbulence or turbulent flow. https://en.wikipedia.org/wiki/Laminar_flow Instrumentation I - Session 3

Laminar and Turbulent Flow Piping bends, corrosion, valves, or any other obstruction to the flow inside a line causes turbulence or turbulent flow. When the path is smooth and without obstruction, the flow is called laminar because the molecules line out to a smooth flowing pattern. This type of movement is characteristic of long pipelines where the molecules have a chance to settle down and move in a more orderly fashion. (streamline flow). The velocity of the flowing fluid changes smoothly and equally from the pipe wall inward to the center of the pipe where the velocity is at its highest. Piping bends, corrosion, valves, or any other obstruction to the flow inside a line causes turbulence or turbulent flow. Instrumentation I - Session 3

Flow Measurement Direct and indirect flow measurement Positive displacement flow measurement Percentage flow rate Volumetric flow units Mass flow units Total flow will be measured directly. Indirect flow measurement, measure flow rate from differential pressure. Flow measurements may be made in exact or absolute quantities, percentages, volumetric quantities of material and also in mass units for solids. Positive …. is used operate by admitting a flowing material into a chamber with a known volume capacity and then transferring all the content to another point. A counter registers a number of times the chamber is filled and discharged. A total amount of metered material can be read directly from the counter. Percentage flow rate is a common way to indicate a flowing process. If a 100 percent is equal to 200 gpm, then a 50% flow rate equals 100 gpm. And so on. Volumetric flow units is based on volume unites per unit time. Such as cubic ft per minute or gallons per mins. Mass flow units are a measure of how much actual mass passes a certain location per unit of time.lb/min Instrumentation I - Session 3

Flow – Primary Flow Sensing and Measurement Instruments Orifice plates Venturi tubes Flow nozzles Pitot tubes Annubr tubes (multiport pitot tubes) Rotameters Electromagnetic meters Turbine meters Mass flow meters These are devices that creates a measurable variable that is proportionally equal to flow rate. Most common ones measure differential pressures. Instrumentation I - Session 3

Orifice Plate Is a piece of 1/8 inch to ½ inch thick metal with a precise hole drilled through it. It can create a pressure drop in a flowing process. Is a piece of 1/8 inch to ½ inch thick metal with a precise hole drilled through it. It can create a pressure drop in a flowing process. Concentric plate in center Eccentric bore off center Segmental plate half moon shaped opening cut into it. Quadrant edged and the conical plates Instrumentation I - Session 3

Orifice Plate Concentric plate in center Eccentric bore off center Segmental plate half moon shaped opening cut into it. Quadrant edged and the conical plates Is a piece of 1/8 inch to ½ inch thick metal with a precise hole drilled through it. It can create a pressure drop in a flowing process. Concentric plate in center Eccentric bore off center Segmental plate half moon shaped opening cut into it. Quadrant edged and the conical plates Instrumentation I - Session 3

Conical orifice plates Instrumentation I - Session 4

Venturi Tube Cone shaped inlet and outlet components. Is used in piping to create a differential pressure. They are more expensive than Orifice plates. Day to day is cheaper because of the less permanent pressure loss. A d/p transmitter can be connected to the two taps to measure the difference in pressure. Is used in piping to create a differential pressure. they are more expensive than op a primary element . day to day is cheaper because of the less permanent pressure loss.cone shaped inlet and outlet components. A d/p transmitter can be connected to the two taps to measure the difference in pressure. Instrumentation I - Session 3

Flow Nozzle The operation of a flow nozzle is the same as a venturi tube on the front side and like an orifice plate on the downstream side. It doesn’t have a recovery cone. It can be inserted into a pipe. They provide a differential pressure. The cost is more than an orifice plate and less than a venturi tube. It doesn’t have a recovery cone. It can be inserted into a pipe. They provide a differential pressure. The operation of a flow nozzle is the same as a venturi tube on the front side and like an orifice plate on the downstream side. The cost is more than an orifice plate and less than a venturi tube. Instrumentation I - Session 3

Pitot Tube Pitot tube is shaped like an L and is inserted into a pipe with the open end facing directly into the flow and another tube measuring or sensing static pressure in the same vicinity. It can detect the velocity of a flowing fluid at only one point in the pipe. Pitot tube is shaped like an L and is inserted into a pipe with the open end facing directly into the flow and another tube measuring or sensing static pressure in the same vicinity. It can detect the velocity of a flowing fluid at only one point in the pipe. Instrumentation I - Session 3

Annubar Tube or multiport pitot tubes TM This tube has four impact points spaced across the pipe facing the flow. And another tube sensing the static pressure. It has a smaller tube inside of the tube that is designed to measure the average pressure measurement across a pipe. Another tube sensing static pressure. It has a smaller tube inside of the tube that is designed to measure the average pressure measurement across a pipe. Instrumentation I - Session 3

Rotameter Direct read variable flow tube in which the fluid enters through the bottom then flows upward, lifting a free floating indicator float. The position of the float can be referenced to the calibrated marks on the glass tube to indicate flow rate. The smallest diameter of the tube is on the bottom. Instrumentation I - Session 3

Electromagnetic Meter (Magmeter) For electrically conductive liquids, slurries, corrosive and abrasive materials. aqueous water based materials. The faster the flow the greater the electrical potential generated. Instrumentation I - Session 3

Turbine Meter It is a flow tube containing a free spinning turbine where rpm is proportional to flow rate. The faster the flow the faster the turbine spins. Instrumentation I - Session 3

Mass Flow Meter Volumetric flow meters can be combined with a density sensor to infer mass flow. Some of meters read mass flow directly. Instrumentation I - Session 3

Differential Pressure (D/P) Transmitter The pressure signal from the primary device is converted into a standard output signal that can represent either differential pressure or flow rate. Read from the book. Instrumentation I - Session 3

Homework Assignments - HWAs Design 6 Matching questions From chapter 4&5 using the following format: Times New Roman, 12 pt. font size, according to the form distributed by Instructor. Handwriting will not be accepted Session 3 - Fall 2015

Homework Assignments - HWAs The Question: The First definition a. Correct Match The Second definition b. Correct Match The Third definition c. Correct Match The Fourth definition d. Correct Match The Fifth definition e. Correct Match The Sixth definition f. Correct Match The answer key for this question and the address in the Book.(the edition, Page and line) Due date: Please email me these questions before coming Friday (September 18th ) at 8 AM. The following week you will ask your questions from the students and explain the answer to us. Your grade for this HWA will be for your extracting and presenting these questions and answers to the class. This HWA will have 5% of your total grade. Please send your questions before the due date otherwise you will lose the whole point. Session 3 - Fall 2015

Homework Assignments - HWAs Example: D/P transmitter a. The measurement from the Float gauge bottom of a tank to the surface of a A curve upper surface of a column of a liquid material Indirect measurement b. Height Innage c. Meniscus A distance from a zero reference point to the surface d. Measures the difference between total pressure and vapor space pressure e. The measurement of another property of a contained material to determine level f. Senses the surface of a material The answer key for this question and the address in the Book.(the edition, Page and line) Session 3 - Fall 2015

Homework Assignments - HWAs The answer key: 1.d 2.f 3.c 4.e 5.a 6.b Session 3 - Fall 2015