advertisement

ESP

50 %
50 %
advertisement
Information about ESP
Education

Published on February 13, 2008

Author: Bianca

Source: authorstream.com

advertisement

Electrostatic Precipitator (ESP):  Electrostatic Precipitator (ESP) Electrical migration Electrical mobility Corona discharge ESP theory Charging mechanisms Ash resistivity Flue gas conditioning Power consumption Reading: Chap. 5 Electrical Migration:  Electrical Migration Coulomb’s law Statcoulomb (stC): the charge that causes a repulsive force of 1 dyne when 2 equal charges are separated by 1 cm (3.3310-10C) Unit charge: 4.8 10-10stC (1.610-19C) (q=ne) Electric Field Millikan Experiment:  Millikan Experiment (Robert Millikan, US, 1868-1953; Nobel Prize Laureate, 1923) Hinds, Aerosol Technology, 1999 http://www.britannica.com/nobel/cap/omillik001a4.html Electrical Mobility:  Electrical Mobility Terminal velocity in an electrical field (electrical migration velocity/drift velocity) (force balance) (for Re < 1) Q: What is the physical meaning of electrical mobility? Q: When does a particle have a higher mobility? May the force be with the particles! Q: Difference between cyclone and ESP in terms of forces acting on the system? What’s the effect? Slide5:  Q: How can we generate charges? Ozone generation - http://www.mtcnet.net/~jdhogg/ozone/ozonation.html Slide6:  1 2 3 1 2 3 (20) (12) (8) Turbulent Flow with Lateral Mixing Model Electrostatic Precipitator Slide7:  Deutsch-Anderson Equation Ac/Q: Specific Collection Area (SCA) Turbulent flow: uniformly mixing Perfect Collection The fraction of the particles removed in unit time = the ratio of the area traveled by drift velocity in unit time to the total cross-section Q: How to increase the efficiency? Slide8:  Q: An ESP that treats 10,000 m3/min of air is expected to be 98% efficient. The effective drift velocity of the particles is 6.0 m/min. (a) What is the total collection area? (b) Assuming the plates are 6 m high and 3 m long, what is the number of plates required? 6 m 3 m Internal Configuration: self-review Charging Mechanism: Diffusion Charging:  Charging Mechanism: Diffusion Charging Random collisions between ions and particles Q: Does q depend on time? Does q depend on dp? The total number of charges on a particle The total charges on a particle Use esu, not SI units. Charging Mechanism: Field Charging:  Charging Mechanism: Field Charging Bombardment of ions in the presence of a strong field Total number of charges by field charging Q: Is the charging rate dependent on particle size? On field strength? On time? On material? Aerosol Technology, Hinds, W. C., John Wiley & Sons, 1999. Saturation charge (Zi ~ 450 cm2/stV•s) Slide11:  Comparison of Diffusion & Field Charging Q: Does collection efficiency increase as particle size increase (because of a higher number of charges)? Nit = 107 s/cm3 = 5.1 E = 5 KV/cm T = 298 K Slide12:  Typical fly ash size distribution Q: If the ESP is used to collect the fly ash, how will the particle size distribution at ESP outlet look like? Resistivity/Conductivity:  Resistivity/Conductivity Impact of particles’ resistivity on ESP’s performance: Factors: temperature, composition Flue gas conditioning 109 - 1010 ohm-cm is desired Q: How does resistivity affect an ESP’s performance? Slide14:  Effects of sulfur content and temperature on resistivity Q: Is S in coal good or bad? Slide15:  Water spray for cement kiln dust Flue Gas Conditioning Slide16:  Effective drift velocity as a function of resistivity by measurement Use the same Deutsch-Anderson Equation with new we. Q: Estimate the total collection area required for a 95% efficient fly-ash ESP that treats 8000 m3/min. The ash resistivity is 1.6×1010 ohm-cm. Slide17:  Good for moderate collection efficiency (90% ~ 95%) Slide18:  High Efficiency ESP (>95%) Matts-Ohnfeldt Equation Use k = 1 for fly ash k = 0.5 or 0.6 for industrial category Rule of Thumb Below 95%, use Deutsch-Anderson Equation Above 99%, use Matts-Ohnfeldt Equation Between them, use an average Q: In designing a high efficiency ESP, a smaller drift velocity is to be used. Why? Power Consumption:  Power Consumption Power density ~ 1-2 W/ft2 Corona power Drift velocity Efficiency vs. Corona Power k = 0.55 for Pc/Q in W/cfs up to 98.5% Quick Reflection:  Quick Reflection

Add a comment

Related presentations

Related pages

ESP - Lexikon - autobild.de

Die Abkürzung ESP steht für Elektronisches Stabilitäts-Programm. Droht das Fahrzeug auszubrechen, bremst das ESP einzelne Räder gezielt ab und hält so ...
Read more

Fahrdynamikregelung – Wikipedia

Benennungen. Das erste Electronic Stability Control wurde 1995 unter dem Namen Elektronisches Stabilitätsprogramm (ESP) von Bosch für das Mercedes S ...
Read more

Entry Page - Entry Page - The ESP Guitar Company

One of the world's leading manufacturers of high quality guitars and basses.
Read more

Elektronisches Stabilitätsprogramm ESP - Kfztech.de

Wie funktioniert ein ESP? ESP ist ein System gegen Untersteuern und Übersteuern, korrigiert Fahrfehler, die zum Schleudern in Kurven führen
Read more

ESP – Wikipedia

ESP steht für: Einführung in die sozialistische Produktion, ein Schulfach in der DDR; English for special purposes, Spezielle themengebundene Begriffe ...
Read more

ESP - definition of ESP by The Free Dictionary

ESP synonyms, ESP pronunciation, ESP translation, English dictionary definition of ESP. n. The supposed ability to perceive events and information by ...
Read more

ESPN: The Worldwide Leader in Sports

Visit ESPN to get up-to-the-minute sports news coverage, scores, highlights and commentary for NFL, MLB, NBA, College Football, NCAA Basketball and more.
Read more

ESP - thomann.de

Über 180 Produkte von ESP sofort lieferbar - versandkostenfrei, 30 Tage Money Back und 3 Jahre Garantie. Thomann - Europas größtes Musikhaus
Read more

Products - Guitars - The ESP Guitar Company

PRODUCTS GUITARS. Guitars are our passion. Since 1975, ESP has created numerous iconic instruments for legendary players spanning every genre of music.
Read more

ESP Sensor - ESP leuchtet - ESP Sensor - ESP leuchtet

ESP ESC DSC VSC PSM DSTC Sensor Beschleunigungs-Sensor Drehraten-, YAW-, DUO-Sensor
Read more