# FLOWMETERS- WORKING & PRINCIPLES

Views:

Category: Entertainment

## Presentation Description

No description available.

## Presentation Transcript

### FLOWMETERS- PRINCIPLES & functioning:

FLOWMETERS- PRINCIPLES & functioning CO-ORDINATOR- Dr. Nidhi PRESENTOR – Dr. Akanksha

### INTRODUCTION:

INTRODUCTION LAMINAR FLOW- Hagen - Poiseuille formula : with constant π / 128 Q = π ∆P r4 / 128 η l TURBULENT FLOW – Depends on: Velocity of fluid Diameter of tube Density Viscosity Q= νρ d/ η

### PowerPoint Presentation:

TUBE- length > diameter ORIFICE- diameter > length Flow rate through orifice depend on: Diameter of orifice Difference in pressure on either side of orifice

### Flow Rate ∞ √ Pressure Diff.:

Flow Rate ∞ √ Pressure Diff.

### Flow Rate ∞ (Diameter)2 :

Flow Rate ∞ (Diameter) 2

### Effect of density :

Effect of density

### FLOW METERS:

FLOW METERS Indicates rate of flow of gas passing through them Also called as flow indicators, flow tubes or rotameters

### HISTORY:

HISTORY Principle described by Kueppers in 1908

### PowerPoint Presentation:

In 1910- rotameters were used to measure N 2 O & O 2 in anesthetic app. Since then were used in industry In 1937 at suggestion of R.H. Salt- modified to familiar form & incorporated in anesthetic app.

### PowerPoint Presentation:

2 types of flow meters Dry or bobbin type Water depression / pressure guage

### PowerPoint Presentation:

Flowmeters in common use have : Constant pressure diff. across an orifice or annular space, area of which varies with flow rate of gas. eg . Rotameter Fixed constriction with pressure diff. on either side which varies with flow rate of gas. eg . Tubular Flow meter, Orifice Flowmeter , Venturi Flowmeter

### VARIABLE ORIFICE METERS:

VARIABLE ORIFICE METERS Coxeter bobbin meter

ROTAMETER

### DESIGN:

DESIGN Mechanical Electronic

### MECHANICAL:

MECHANICAL Gas flow measurement depend on principle that flow past a resistance is proportional to pressure Measure the drop in pressure that occurs when gas pass through a resistance

### PHYSICAL PRINCIPLES:

PHYSICAL PRINCIPLES

### PowerPoint Presentation:

Rate of flow through tube depend on 3 factors: Pressure drop across the constriction: Size of the annular opening: Physical characteristic of the gas- low flow- laminar and depend on viscosity High flow- turbulent and depend on density

### PowerPoint Presentation:

Orifice – density of gas play imp. part in determining its flow rate For ideal orifice across which pressure diff is constant: Vol. flow rate of gas= 1/ 2 √ density

### PowerPoint Presentation:

If gas A passed through an ideal orifice in a meter calibrated for gas B Actual flow of gas = 2 √ density of gas A flow indicated on B meter density of gas B

### PowerPoint Presentation:

Temperature & pressure effects: Calibrated at atm pressure & room temp (200c) Slight change with temperature Hyperbaric chamber- deliver less gas than indicated Decreased pressure- flow rate greater than indicated

### PowerPoint Presentation:

Correction factor for changes in atm. Pressure F1= F0 x ( d0/d1) Where F1= flow at ambient presure F0= flow on scale calibrated at sea level d0= density of gas at sea level d1= density of gas at ambient presure

### FLOW METER ASSEMBLY:

FLOW METER ASSEMBLY Consists of: Tube Indicator Stop Scale

### Flowmeter assembly:

Flowmeter assembly

INDICATORS

STOP & SCALE

TUBE ARRANGEMENT

### Arrangement of the Flow-Indicator Tubes:

Arrangement of the Flow-Indicator Tubes

### PROBLEMS WITH FLOWMETERS:

PROBLEMS WITH FLOWMETERS Inaccuracy Indicator problem Leaks Using wrong flowmeter

### PowerPoint Presentation:

AUXILLARY FLOWMETER FOR OXYGEN-

### HYPOXIA PREVENTION SAFETY DEVICES:

HYPOXIA PREVENTION SAFETY DEVICES Mandatory minimum oxygen flow: 50-250ml/min Minimum oxygen ratio Mechanical linkage

### PROPORTIONIG SYSTEM:

PROPORTIONIG SYSTEM Mechanical integration of the N2O and O2 flow-control valves Automatically intercedes to maintain a minimum 25% concentration of oxygen with a maximum N2O:O2 ratio of 3:1

### Limitations of Proportioning Systems:

Limitations of Proportioning Systems Machines equipped with proportioning systems can still deliver a hypoxic mixture under the following conditions: Wrong supply gas Defective pneumatics or mechanics (e.g.. The Link-25 depends on a properly functioning second stage regulator) Leak downstream (e.g.. Broken oxygen flow tube) Inert gas administration: Proportioning systems generally link only N2O and O2

FLOW ADJUSTMENT CONTROL Two types: Mechanical Electronic

MECHANICAL

### ELECTRONIC FLOWMETERS:

ELECTRONIC FLOWMETERS

HEIDBRINK METER

### CONNEL FLOW METER:

CONNEL FLOW METER

### FIXED ORIFICE METERS:

FIXED ORIFICE METERS 1.PRESSURE GUAGE METER

### PowerPoint Presentation:

2.WATER DEPRESSION METER

### 3. METERS WITH CAPILLARY CONSTRICTION :

3. METERS WITH CAPILLARY CONSTRICTION

### PowerPoint Presentation:

4. FOREGGER METER

### PowerPoint Presentation:

5. WATER SIGHT- FEED METER

THANK YOU