Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
  • B03C3/02—Plant or installations having external electricity supply
  • B03C3/16—Plant or installations having external electricity supply wet type
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
  • B03C3/34—Constructional details or accessories or operation thereof
  • B03C3/36—Controlling flow of gases or vapour

Definitions

• the invention relates to a method for cleaning dust-laden process exhaust gases in a wet electrostatic precipitator.
• wet electrostatic precipitators are aggregates for dust separation, which are increasingly used for fine dust separation.
• the design of electrostatic filters is usually based on the German equation.
• the speed of migration is dependent on several parameters, such as dust particle size, dust composition and exhaust gas speed.
• Wet electrostatic precipitators are usually designed for exhaust gas flow velocities of 1.5 m / s to 2 m / s. For example, due to the small particle sizes, migration speeds on the precipitation electrode surface of approx. 10 cm / s result for the dust removal system. This low exhaust gas velocity requires an increased outlay for flow distribution devices on the inlet and outlet sides in the filter in order to equalize the exhaust gas flow. Exhaust gas flow velocities of the order of magnitude of approximately 20 m / s usually occur within exhaust gas channels before and after the filter. This means an acceleration on the outlet side of the filter or a deceleration on the inlet side of the filter by a factor of approx. 10-13 each.
• the object of the invention is to provide a method for cleaning dust-laden exhaust gases in a wet electrostatic precipitator, which is characterized in that the exhaust gas flow rate is set to a value so that the highest possible rate of migration occurs and at the same time the disadvantages of the prior art, in particular complex flow equalization devices and large precipitation electrode areas can be avoided.
• wet electrostatic precipitators in the sense of the invention are understood to mean both those in which the exhaust gas is completely or almost completely saturated with water vapor before entering the filter, and those in which the exhaust gas has a significant undersaturation of water vapor when it enters the filter. In the latter wet electrostatic precipitators, the precipitation electrodes must therefore be cleaned by additional water injection.
• the subject invention which is characterized in that the exhaust gas flow rate is set to a value of 4 m / s to 9 m / s.
• the exhaust gas flow rate is set to a value of 4 m / s to 9 m / s.
• the precipitation electrode area and thus also the weight of the precipitation electrode can be reduced in relation to the increase in the rate of migration while the efficiency remains the same. Furthermore, the effort for flow equalization devices on the inlet and outlet side of the filter is thus minimized (deceleration or acceleration only by a factor of approx. 2-5). The wet electrostatic precipitator is reduced accordingly, which means that the investment costs are also lower.
• Fig. 1 Graph of exhaust gas flow velocity vs. Migration speed
• Fig. 2 Diagram of grain size classes vs. accumulated concentrations
• the migration speed increases approximately linearly up to exhaust gas speeds of approx. 6 m / s; at higher speeds, the curve becomes flatter.
• the range of 4 m / s to 9 m / s according to the invention there is hardly any undesired drop detachment.
• the dust-laden raw gas from a sintering plant is first passed through a scrubber. Larger particles (> 16 ⁇ m) are pre-separated and the gas is enriched or saturated with water vapor. The fine separation takes place in the wet electrostatic precipitator described above.

Landscapes

• Electrostatic Separation (AREA)
• Treating Waste Gases (AREA)
• Filtering Of Dispersed Particles In Gases (AREA)
• Lasers (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=3495450

Family Applications (1)

Country Status (6)

Citations (1)

• 1997
  • 1997-04-11 AT AT0062197A patent/ATA62197A/de not_active Application Discontinuation
• 1998
  • 1998-04-03 DE DE59805002T patent/DE59805002D1/de not_active Expired - Fee Related
  • 1998-04-03 EP EP98912138A patent/EP0973615B1/de not_active Expired - Lifetime
  • 1998-04-03 AT AT98912138T patent/ATE221416T1/de not_active IP Right Cessation
  • 1998-04-03 WO PCT/AT1998/000088 patent/WO1998046359A1/de active IP Right Grant
  • 1998-04-03 CN CN98804050.6A patent/CN1252016A/zh active Pending
  • 1998-04-03 AU AU67116/98A patent/AU735231B2/en not_active Ceased

Patent Citations (1)

Also Published As

Similar Documents

Legal Events