Guided Wave Radar Technology

Transcription

1 Guided Wave Radar Technology Lauro Cantu, Jr. Emerson Process Management Standards Certification Education & Training Publishing Conferences & Exhibits

2 Presenter Lauro Cantu, Jr. Over ten years of radar level experience. Experience in different industries including: Marine Oil & Gas Offshore/Onshore Production Refining Chemical 2

3 Measurement Principle - GWR TDR (Time Domain Reflectometry) technology Microwave pulses guided down a probe Pulse reaches media with different dielectric constant, part of energy is reflected back Distance = Speed X Time of travel /2 Part of pulse continues until reflected at lower product surface Click picture to run movie again 3

4 Measurement principle -Level & Interface Part of pulse continues until reflected at lower product surface Click picture to run movie 4

5 Measurement principle -Level & Interface TDR (Time Domain Reflectometry) technology Microwave pulses guided down a probe Pulse reaches media with different dielectric constant, part of energy is reflected back Distance = Speed X Time of travel /2 Part of pulse continues until reflected at lower product surface 5

6 Three Measurement Variations Are Possible Level Only Level and Interface Interface w/immersed Probe 6

7 Interface Measurements: Density VS Dielectric Changes Is density or dielectric going to change? How significant is the change? Is it only changing in the upper layer or both layers? 22 (550 mm) Example of top fluid changes: Density (SG) change from 0.7 to 0.9 Dielectric εr change from 1.8 to 2.0 SG of 0.2: error = 4.4 (110 mm) εr of 0.2: error = 0.9 (22.5 mm) 32 (800 mm) displacer cage with an interface at midrange 7

8 Full range of Probe Styles Coaxial Rigid Twin Flex. Twin Rigid Single Flex. Single 8

9 Probe types and their Wave shapes - Different applications require different probes Coaxial Not affected by disturbing objects, turbulence, low dielectrics Clean applications Twin Leads Better than coaxial for viscous media Avoid product bridging between probes Single leads Best choice for highly viscous, thick or dirty media Avoid nearby objects Propagation of Energy 9

10 Probe types and their Wave shapes - Different applications require different probes Coaxial Not affected by disturbing objects, turbulence, low dielectrics Clean applications Twin Leads Better than coaxial for viscous media Avoid product bridging between probes Single leads Best choice for highly viscous, thick or dirty media Avoid nearby objects 10

11 Extreme Pressures and Temperatures 6. Overall length accommodates flanges up to class Flexible probe load system 5. Moisture barrier 4. Brazed Hermetic/ Gas-tight seal isolated from the process and outside forces on the probe 3. Flexible locking system compensates for thermal expansion and fastens the ceramics 1. Temperature and pressure seal with ceramic insulators and graphite gaskets provide robust thermal and mechanical barrier as well as chemical resistance Probe 11

12 Select the correct probe for the application Single handles coating Twin causes Bridging 12

13 Typical Applications for Guided Wave Radar 13

14 Replacing older level technologies Utilizing GWR to replace older existing level technologies. Technologies that are vulnerable to density changes and high maintenance. More accurate interface level measurement. Diagnostics 14

15 Vaporizer Inaccuracies with system due to density changes. Problems with temperature effects. Replaced with GWR on bridle assembly. 15

16 Waste Water Reflux Drum Fully Immersed Interface application. Hydrocarbon and Water interface application. Existing technology had problems with density changes and high maintenance with poor control. Enabled control into DCS and improved reliability. 16

17 Separators/Knockout Drums Separators: Measures interface of two fluids Knockout drum: level of gas/fluid and possible measurement of oil/water interface in boot alky unit with sulfuric acid Density can change with temp swings and crude feedstock changes 17