Acoustic ash removal

Abstract

An acoustic system having a plurality of speakers applying acoustic energy as a series of acoustic waves to various target sites on the exterior of the reactor to vibrate and deflect the interior surfaces of the reactor structure such that the slag is dislodged from the internal surfaces of the reactor structure. Each speaker generates acoustic waves having a waveform corresponding to the resonant frequency of the ash crystallized on the reactor structures. The acoustic waves induce vibrations and/or deflections in the portion of the reactor wall to which the slag is engaged as well as the slag itself breaking the interstitial bonds of the slag deposit and bonding holding the slag to the wall. The separated or disintegrated slag can then be gravimetrically fall to the bottom of the reactor for removal from the reactor.

1 . An acoustic system for removing slag from an interior surface of a reactor, comprising:
 at least one speaker further comprising:
 a driver assembly having a speaker coil and a permanent magnet, wherein the speaker coil is positioned proximate to the permanent magnet such that supplying an alternating current to the speaker coil induces a magnetic field in the speaker coil oscillating the speaker coil along a central axis, and 
 a cone assembly having a cone having a first end and a second end, wherein the cone comprises a frustoconical shape in which the first end has a smaller diameter than the second end, 
 wherein the first end of the cone assembly is operably engaged to the speaker coil such that the central axis intersects the center of the first and second ends and the oscillation of the speaker coil induces a corresponding oscillation in the cone along the central axis to generate at least one acoustic wave centered on the central axis; 
   wherein the speaker can be oriented to supply at least one acoustic wave to the interior surface of the reactor to induce a deflection and vibration in the inner surface by aligning the central axis with an exterior surface of the reactor corresponding to the interior surface.   
     
     
         2 . The acoustic system of  claim 1 , wherein the driver assembly further comprises a driver housing for receiving the speaker coil and permanent magnet, wherein the driver housing comprises an open end through which the speaker coil is engaged to the cone and a closed end defining at least one hole such that oscillation of the speaker coil induces an oscillation of air through the holes. 
     
     
         3 . The acoustic system of  claim 1 , wherein the speaker coil further comprises a safety circuit having a plurality of rectifiers arranged in parallel and set at graduated power thresholds, wherein the alternating current passes through the rectifiers causing each rectifier to disconnect as alternating current exceeds the corresponding power threshold until the speaker coil is disconnected and ceases oscillating. 
     
     
         4 . A method for removing slag from an interior surface of a reactor having a plurality of structural supports, comprising:
 locating a target site on an exterior surface of the reactor corresponding to the interior surface, wherein the target site is approximately equidistant from at least two adjacent structural supports along a linear axis;   aligning a speaker adapted to provide at least one acoustic wave centered on a central axis with the target site such that the central axis aligns with the target site;   apply at least one first acoustic wave generated by the speaker to the target site;   resting for a predetermined time before applying at least one second acoustic wave generated by the speaker to the target site; and   examining the target site to ascertain the amount of slag removed.   
     
     
         5 . The method of  claim 4 , further comprising applying at least one third acoustic wave to the target site having at least one modified waveform characteristic determined from the evaluation of the reactor following the application of the at least one second wave, wherein the waveform characteristic can be selected from the amplitude of the acoustic wave, the frequency of the acoustic wave, and combinations thereof. 
     
     
         6 . A method for removing slag from an interior surface of a reactor having a plurality of structural supports, comprising:
 locating a target site on an exterior surface of the reactor corresponding to the interior surface, wherein the target site is equidistant from at least two adjacent structural supports along a linear axis;   striking the exterior surface of the reactor at the target site to induce an acoustic response from the reactor and the slag adhered to the interior surface of the reactor;   evaluating the acoustic response to ascertain a resonant frequency of the slag adhered to the interior surface of the reactor;   selecting a first amplitude and a first frequency for an acoustic wave capable of inducing resonance in the reactor and adhered slag at the resonant frequency;   aligning a speaker adapted to provide the acoustic wave centered on a central axis with the target site such that the central axis aligns with the target site; and   applying at least one first acoustic wave having the selected first amplitude and first frequency to the target site to induce resonance in the reactor and the slag adhered to the interior surface.   
     
     
         7 . The method of  claim 6 , further comprising:
 striking the exterior surface of the reactor at the target site after application of the at least one first acoustic wave to induce an second acoustic response from the reactor and the slag still adhered to the interior surface of the reactor;   evaluating the second acoustic response to ascertain a second resonant frequency of the slag adhered to the interior surface of the reactor;   selecting a second amplitude and a second frequency for a second acoustic wave capable of inducing resonance in the reactor and adhered slag at the second resonant frequency; and   applying at least one second acoustic wave having the selected second amplitude and second frequency to the target site to induce resonance in the reactor and the slag adhered to the interior surface.