Abstract: A gas separation apparatus which uses electrostatic precipitators and a DC power supply is controlled to optimally remove moderate to high resistivity ash. The DC power supply is pulse width modulated to maximize the product of the peak electric field and the average electric field. The method used to optimize operation includes selecting initial on and off times for the power supply, operating the power supply using the initial off and on times, and progressively decreasing the off time. A determination is made whether the off time may be further decreased. Ultimately, the on and off time intervals that produce the highest peak and average voltage are determined, and the system is operated using these parameters. A procedure may be periodically repeated to monitor the process and detect if there has been a change in the system that would require new time intervals.

Abstract: A flue gas purification system comprising in the flue gas stream an electrostatic precipitator, mercury sorbent injection and a two-stage electrostatic separator, and wherein the mercury sorbent injection is positioned between the electrostatic precipitator and the two-stage electrostatic separator.

Abstract: Disclosed is a method of treating, fly ash having an unacceptably high concentration of carbon, with ozone produced in situ by corona discharge. This method will allow high carbon-content fly ash to be used with air entrainment agents as an additive to cement. The corona discharge can be produced in the exhaust pipe with a venturi of various combustion systems. The device of this invention can be used in conjunction with a triboelectric carbon-fly ash separation system or in a conventional combustion system. The corona discharge is produced off of sharp-tipped metal devices. A venturi is used in the exhaust pipe in the exhaust pipe in conjunction with the sharp-tipped metal devices.

Abstract: Disclosed is a method of treating, fly ash having an unacceptably high concentration of carbon, with ozone produced in situ by corona discharge. This method will allow high carbon-content fly ash to be used with air entrainment agents as an additive to cement. The corona discharge can be produced in the exhaust pipe of various combustion systems. The device of this invention can be used in conjunction with a triboelectric carbon-fly ash separation system or in a conventional combustion system. The corona discharge is produced off of sharp-tipped metal devices.

Abstract: An electrostatic precipitator for removing sulfur dioxide and other polluting particles has a wet liquid removal area or compartment down stream and in the last section of plates of the electrostatic precipitator.

Abstract: A two-stage electrostatic separator for separating particles from a particle laden gas stream includes a pre-charging section and spaced-apart gas-permeable grounded and discharge electrodes charged at opposite polarities and defining a separating section between them, the grounded electrode being positioned upstream from the discharge electrode. The particles in the particle laden gas stream are pre-charged to a certain charge in the pre-charging section and penetrate through the grounded electrode into the separating section, where the particles are separated from the particle laden gas stream. As a result, a clean gas stream exits from the separating section through the discharge electrode, and the particles separated from the particle laden gas stream are partially collected on the grounded electrode, and partially are removed with a bleed flow which is recirculated. The electrodes may be of linear or cylindrical shape, and linear electrodes may be arranged in a "zig-zag" order.

Abstract: A two-stage electrostatic separator for separating particles from a particle laden gas stream includes a pre-charging section and spaced-apart gas-permeable grounded and discharge electrodes charged at opposite polarities and defining a separating section between them, the grounded electrode being positioned upstream from the discharge electrode. The particles in the particle laden gas stream are pre-charged to a certain charge in the pre-charging section and penetrate through the grounded electrode into the separating section, where the particles are separated from the particle laden gas stream. As a result, a clean gas stream exits from the separating section through the discharge electrode, and the particles separated from the particle laden gas stream are partially collected on the grounded electrode, and partially are removed with a bleed flow which is recirculated. The electrodes may be of linear or cylindrical shape, and linear electrodes may be arranged in a "zig-zag" order.