Research-cottrell

Paul L Feldman

Robert J Gleason

Asim B Ray

Krishnaswamy Sampathkumar

A method for reduced temperature operation of flue gas collectors is disclosed wherein the benefits of low temperature operation are made possible by avoidance of the acid dewpoint limit. The process increases the specific collecting area of the collector, results in lower pressure drop through the collector and, where the collector is an electrostatic precipitator, allows improved collection efficiency through higher electric field strength and reduced particulate resistivity.

Method for reduced temperature operation of flue gas collectors

A process uses limestone injection into a combustion boiler burning pulverized coal or liquid hydrogen fuel. Effluent gas from the boiler is humidified and cooled to below 200.degree. F. During the humidifying and cooling step, sulfur dioxide removal occurs in addition to that which takes place in the combustion zone of the boiler. The effluent gas and unreacted alkali is then fed into an electron beam irradiation chamber which produces energetic conditions for rapid reaction of sulfur dioxide and nitrogen oxides in the presence of water vapor. The remaining unreacted alkali reacts rapidly and in-situ with the sulfuric acid and nitric acid formed in the electron beam chamber.

Process for treating flue gas with alkali injection and electron beam

Converting both organic and inorganic sulfur compounds in coal to removable forms utilizing electron beam irradiation. The removable forms of sulfur include elemental suflur, gaseous compounds, and water-soluble compounds. Coal is pulverized and slurried and introduced into the electron beam reaction chamber where the conversion reactions take place. As a further benefit, coal dechlorination inherently results.

Electron beam coal desulfurization

Parameters for optimum operation of a pulsed multisection electrostatic precipitator are disclosed: It has been discovered that superior particulate collection can be achieved by a combination of pulse and conventional DC voltages. The pulse rise time and decay time are made short enough so that adverse sparking conditions do not develop. The base voltage (conventional DC voltage) is adjusted in coordination with the superposed pulse characteristics (pulse voltage, pulse frequency and pulse shape) to maintain an average current through the collected dust layer just below or at that value which would cause electrical breakdown of the dust layer. Base voltage may actually be below normal corona starting voltage in some cases. The pulse produces instanteously very high ion densities and electric field strengths. In one design of precipitator, alternate sections are pulsed, with the other alternate sections functioning as collecting sections and merely having DC base voltage applied thereto. In other designs, all sections including the collecting sections, may be pulsed to provide sufficient current to hold the collected particles on the collecting surfaces and to prevent reentrainment. In some designs, at least one of the sections may be a transmission line which is pulsed.

Pulsed electrostatic precipitator

A wetted parallel plate collecting electrode arrangement which increases the maximum electric field intensity possible without having water draining off the lower edges of the collecting electrodes forming small droplets which are accelerated towards the opposite electrodes. An electrically conductive partition plate maintained at a voltage intermediate the voltages on the electrodes is disposed between the lower edges of oppositely charged electrodes and extends above and below the lower edges of the electrodes. Preferably, the partition plate is electrically 'floating' and receives its voltage due to the effects of the electric field between the collecting electrodes.

Growing community of inventors

Bridgewater, NJ, United States of America

Paul L Feldman