US 6,551,382 B1 · Hot-humid/cold gas scrubbing process and apparatus

Abstract

Effluent gas cleaning process and apparatus for effectively removing particulates in the 0.01 micron to 0.1 micron diameter range, and for removing water-soluble gaseous contaminants, by first bringing the effluent to a relatively high temperature and humidity in a first stage, and then exposing the effluent to copious quantities of small cool water droplets in a second stage, for particular combinations of: the first stage relative humidity; the first-to-second stage droplet temperature difference; the stage two water droplet mass flow rate vs. effluent flow rate; the second stage droplet size; the travel time of the effluent during exposure to the cool droplets; and the electrical charge state of the second stage water droplets and opposite charge state of the particulates. The combinations enhance effluent cleaning through the combined operation of up to four distinct physical processes which can be made to occur during the second stage.

Claims20

Dependent claims

Process for cleaning contaminant gases and contaminant particulates from a flowing effluent gas, comprising the steps of:

(a) bringing said effluent gas, in a first stage, to a temperature T1 and a relative humidity RH1;
and
(b) exposing said effluent gas, in a second stage, to copious quantities of cool liquid droplets having a temperature T2;
where
said process has operating parameters sufficiently close to the following optimal operating parameters:
(1) The relative humidity RH1 in said first stage exceeds 95%;
(2) The temperature difference T1−T2 is at least 15 deg. Fahrenheit;
(3) The mass flow rate of the cool liquid droplets in said second stage at least equals the mass flow rate of the effluent gas being cleaned by said process;
(4) The cool liquid droplets in said second stage have an average diameter no larger than 200 microns;
(5) The cool liquid droplets in said second stage each bear an electrical charge having a magnitude which is at least an appreciable portion of the theoretical maximum charge such a droplet may carry;
(6) The travel time of said effluent gas through the cool liquid droplets in said second stage is at least 2 seconds;
and
(7) Said particulates and said cool liquid droplets in said second stage have opposite electric charge polarity;
to achieve a desired collection efficiency for removal of said contaminants from said effluent gas, for particulates of the size range of interest to an operator of said process.

11 more elements

Dependencies are inferred from the claim text.

Hot-humid/cold gas scrubbing process and apparatus

Life of this patent

Hot-humid/cold gas scrubbing process and apparatus

Life of this patent

Abstract

Claims20