Surface condensation process and device for efficiently removing coal combustion fly ash microspheres

Abstract

A surface condensation process and device for efficiently removing coal combustion fly ash micro spheres are provided. The device is comprised of a patterned-plate type atomizer, a flow meter, an ultrasonic drive power source, an automatic temperature controller, a heat-tracing pipeline, a condensation sleeve, an electrically heated water storage tank, a water pump and an electrostatic precipitator.

Claims

1. A surface condensation process for efficiently removing coal combustion fly ash microspheres, comprising: (1) utilizing, ultrasonic waves to atomize high-temperature water into 10-20 m monodispersing droplets of particulate matter and increasing a saturation ratio of smoke to a supersaturated state saturation ratio; (2) controlling temperature of the droplets to be 80-90 C., with a temperature difference of 30-40 C. between the droplets and coal combustion smoke; (3) after atomized droplets being accelerated by a Laval diffusion tube at a rear of an atomizer head, mixing high speed cross flow of coal-fired smoke to make the droplets and microspheres collide, coagulate and absorb each other to form bigger microspheres; (4) in the supersaturated state, controlling temperature of liquid inside a condensation sleeve and outside a smoke pipe to be 20 C. to lower the temperature of the smoke by 1-5 C., vapor in the smoke adsorbed on an outer surface of the micro spheres due to high surface adsorption capability of the microspheres, quickly forming beadshaped condensation with micro-bulges on a surface of the microspheres cores, and hence decreasing a specific resistance of the microspheres by 1-2 orders of magnitude, (5) controlling the atomized droplets remaining in the smoke for 300 ms-1 s before the atomized droplets entering into an electrostatic precipitator, and then the atomized droplets enter into the electrostatic precipitator with the smoke.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is schematic view of a system for coal-fired fly ash microsphere surface condensation process;

(2) FIG. 2 is schematic view of an atomization system;

(3) FIG. 3 is cross sectional view of a patterned-plate type atomizer along line A-A;

(4) FIG. 4 is cross sectional view of the patterned-plate type atomizer along line B-B;

(5) FIG. 5 is schematic view of a condensation sleeve.

(6) Wherein, label 1 is a flow meter, 2 is a an ultrasonic drive power source, 3 is a power source display, 4 is a heat-tracing pipeline, 5 is a patterned-plate type atomizer, 6 is a condensation sleeve, 7 is an electrostatic precipitator, 8 is a high-voltage power source, 9 is an ash hopper, 10 is a room-temperature water inlet pipeline, 11 is heat exchanged water heat-tracing pipeline, 12 is an electrically heated water storage tank, 13 is a smoke inlet pipeline, 14 is an ultrasonic power regulator, 15 is a housing of the patterned-plate type atomizer, 16 is a water pump, 17 is an external heating sleeve of the water storage tank, 18 is a heating controller of the water storage tank, 19 is an ultrasonic transducer, 20 is an external heat insulation sleeve, 21 is a water inlet of a atomizer head, 22 is a main water inlet pipe, 23 is a water inlet branch pipe, 24 is a Laval outlet pipe, 25 is a patterned-plate flange, 26 is a smoke pipeline flange, 27 is the atomizer head, 28 is a patterned plate, 29 is a condensed water sleeve, and 30 is a heat exchanged water outlet pipeline.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(7) The preferred embodiments of the present invention will be described in the following referring to FIGS. 1-5.

(8) As shown in the figures, the atomization system of the present invention is composed of an electronically heated water storage tank 12, a water pump 16, a flow meter 1, an ultrasonic drive power source 2, a power source display 3, a heat-tracing pipeline 4, and a patterned-plate type atomizer 5. The patterned-plate type atomizer 5 is composed of a housing of the patterned-plate type atomizer 15, an ultrasonic power regulator 14, an external heat insulation sleeve 20, an atomizer head 27, a water inlet of an atomizer head 21, a main water inlet pipe 22, a water inlet branch pipe 23, a Laval outlet pipe 24, a patterned-plate flange 25, and a patterned plate 28, The atomizer head 27 is welded on the patterned plate 28 in way of circumferential direction, Water enters into a condensed water sleeve 30 via a room-temperature water inlet pipeline 10, exchanges heat with the smoke and then discharges from a heat exchanged water outlet pipeline 29, and the temperature of the smoke decreases 1-5 C. and the temperature of the water increases 5-10 C. The water with increased temperature automatically flows into the electrically heated water storage tank 12 under high gravity via a heat exchanged water heat-tracing pipeline 11 and is heated by a heating controller 18 of the water storage tank, and the temperature in the water storage tank is controlled by an external heating sleeve 17 of the water storage tank. The heated high-temperature water is fed into the atomization system via a water pump 16, flow meter 1 and heat-tracing pipeline 4 respectively. The ultrasonic power regulator 14 is used to regulate the parameters of the ultrasonic drive power source 2 and the power source display 3 to control atomization quantity. The high-temperature water flows into the main water inlet pipe 22 via the heat-tracing pipeline 4, and is distributed to various water inlet branch pipes 23, and then enters into the ultrasonic transducer 19 via the atomizer head 21. After high frequency vibration is applied to the water in the atomizer head 27, 10-20 m monodispersing droplets of particulate matter are generated. The temperature of the liquid to be atomized is controlled by the external heat insulation sleeve 20 of the atomizer so as to control the temperature of the atomized droplets. After it is accelerated by the Laval outlet pipe 24 at the rear of the atomizer head, the atomized droplets enter into a smoke inlet pipeline 13. By regulating the temperature of the condensation sleeve 6 and the external heat insulation sleeve 20, the temperature of the condensation sleeve is controlled to slightly decrease (by 1-5 C.) the temperature of the smoke. Taking advantageous of the high absorbability of the surface of the microspheres, the steam in the smoke is absorbed on the surface of the microspheres or enters into the microspheres via the thin shell of the microspheres, so as to decrease the specific resistance of the microspheres by 1-2 orders of magnitude. Through the smoke inlet pipeline 13, the microspheres carried by the coal-fired smoke and the high-speed cross-flow atomized droplets thoroughly collides, aggregates and absorbs each other, the microspheres aggregate, condense and enters into the electrostatic precipitator 7 along with the smoke. A high-voltage power source 8 is used to provide high voltage for the discharge electrode of the electrostatic precipitator 7, the discharge electrode is prompted to ionize the surrounding gas to generate negative ions and electrons, and the electrons collide with the modified microspheres. The electrostatic absorption process is completed under the action of electric field. Thus, clean smoke is released into the atmosphere. The particles are irrigated into the ash hopper 9 by a water-film dust-cleaning system of the electrostatic precipitator 7, and then are discharged into ash pool.