Surface blasting apparatus

A surface blasting apparatus of the type using abrasive particles to clean a surface comprising:

• an abrasive blast wheel for throwing abrasive particles against a surface to be treated;
• an abrasive storage hopper for providing a supply of abrasive particles to said abrasive blast wheel;
• abrasive particles stored in said storage hopper;
• an abrasive return chute for returning abrasive particles rebounded from said surface, and for passing a stream of abrasive particles upwardly and laterally in said chute, said chute being inclined at an acute angle to the vertical and enclosing and defining an upwardly and laterally extending abrasive particle flow path which corresponds generally to the angle of rebound of abrasive particles from said surface;
• means for inducing entry of air into said stream of abrasive particles moving upwardly in said return chute for removal of dust and debris therefrom;
• and
• baffle means positioned adjacent and above the exit of said abrasive return chute within the projection of the upwardly and laterally extending abrasive flow path and defining an undulating, tortuous air-flow path from the lower side thereof to the upper side thereof, and positioned to receive air, dust and a portion of the rebounded abrasive particles from the exit at the upper end of said abrasive return chute and for allowing said air to flow upwardly through said tortuous, undulating path defined by said baffle means, while preventing the movement of a major portion of the abrasive particles upwardly through said baffle means in opposition to the force of gravity exerted downwardly thereon, thereby enabling the air moving through said baffle means to scrub the abrasive particles to remove dust and debris therefrom, said baffle means being positioned directly above the exit of said abrasive return chute so that a substantial portion of the abrasive particles rebounded from said surface rebound directly and in a straight line onto said baffle means, and so that a portion of the kinetic energy of said particles is dissipated by impact with said baffle means.

A surface blasting apparatus comprising:

• an abrasive blast wheel for throwing abrasive against a surface to be cleaned by the scouring action of abrasive particles impinging on said surface;
• an abrasive storage hopper for providing a supply of abrasive particles to said abrasive blast wheel;
• an abrasive return chute for receiving abrasive particles rebounding upwardly from said surface to be cleaned by abrasive particle scouring action, and for conducting a stream of such rebounding abrasive particles upwardly and laterally in said chute at an angle to the vertical;
• means for producing the entry of air into said stream of abrasive particles moving upwardly and laterally in said chute for movement with the particles;
• baffle means defining an undulating, tortous air-flow path from the lower side thereof to the upper side thereof, and positioned adjacent and above an exit at the upper end of said abrasive return chute for allowing said air to flow upwardly therethrough through said tortuous, undulating path around portions of said baffle means while preventing the movement of a major portion of the abrasive particles upwardly through said baffle means in opposition to the force of gravity exerted downwardly thereon, to thereby enable the air moving through said baffle means to scrub the abrasive particles to remove dust and debris therefrom;
• magnetic abrasive particle receiving and arresting means positioned adjacent said baffle means at a location at one side of said baffle means in a vertically extending plane which extends across and intersects the path of upward and lateral movement of abrasive particles in said abrasive return chute, whereby a portion of the air moving upwardly in said return chute with said abrasive particles will impinge against said magnetic abrasive particle receiving and arresting means, and against abrasive particles magnetically held thereon, and whereby a portion of said abrasive particles shall impact said magnetic abrasive receiving and arresting means and be held thereon for subjection to a scrubbing action by air moving therepast, said held particles being removed from said arresting means by impact of additional magnetic particles rebounding upwardly in said abrasive return chute, said baffle means and said magnetic particle receiving and arresting means cooperating with each other and with gravity to (a) change the direction of movement of said abrasive particles from upward and laterally with respect to said surface to be cleaned, to downwardly, and to (b) thoroughly air scrub said abrasive particles to remove dust and debris therefrom and entrain such dust and debris in air moving upwardly through said baffle means;
• and
• conveyor means having a portion below said baffle means and said magnetic particle arresting means for catching gravitating abrasive particles falling from said baffle means and said arresting means, and for conveying said abrasive particles to said abrasive storage hopper for re-use in said surface blasting apparatus.

In a surface blasting apparatus of the type using abrasive particles to impact a surface to be cleaned, the improvement which comprises:

• a horizontally extending screen for removing large debris from the abrasive particles used in said surface blasting apparatus, and defining openings through which the abrasive particles gravitate downwardly therefrom;
• means for directing air across the underside of said screen in a horizontal direction of flow substantially normal to the gravitating abrasive particles for cleaning the abrasive particles as the air passes therethrough;
• a large debris chute positioned under one end of said horizontally extending screen for receiving said removed large debris from said screen;
• dust removing means for removing dust from air which has been directed past and across said falling abrasive particles for cleaning the abrasive, said dust removing means including:
• a pre-filter for removing coarse dust from said air used to clean the abrasive used in said surface blasting apparatus;
• and
• additional filters positioned for receiving air and relatively fine dust from said pre-filter and for separating dust from the air received in said additional filters;
• a first cleaning chamber containing said pre-filter and positioned for receiving said large debris discharged from said large debris chute, and for also receiving at least a portion of said coarse dust removed by said pre-filter forming a part of said dust removing means, said first cleaning chamber having a lower portion;
• a second cleaning chamber containing said additional filters and positioned alongside and adjacent said first cleaning chamber for receiving at least a portion of said relatively fine dust removed by said additional filters forming a part of the dust removing means, said second cleaning chamber having a lower portion, and said adjacent first and second cleaning chambers defining a common, horizontally extending opening at the lower portions of said first and second cleaning chambers;
• and
• auger means in the lower portions of said first and second cleaning chambers for transferring the dust and large debris received in the first and second cleaning chambers toward said common opening.

In a surface blasting apparatus for cleaning a surface by directing abrasive particles against the surface, which apparatus includes an abrasive propelling wheel for propelling abrasive particles against the surface to be cleaned, and means for recycling the abrasive particles rebounding from the surface to be cleaned through a circuitous return path to a supply hopper for resupply to the abrasive propelling wheel, and further including means for moving a stream of air along at least a portion of said abrasive particle circuitous return path in admixture with the abrasive particles moving through said circuitous return path, the improvement for cleaning the abrasive particles of dust and debris while said abrasive particles are transvering said circuitous return path and prior to their return to the supply hopper, said cleaning being effected by means of air washing the abrasive particles at at least two points along said circuitous return path with air derived from said air stream, said cleaning by the air washing improvement comprising:

• cleaning means located at an upstream, first cleaning point in said circuitous return path, said cleaning means being positioned to divert and separate a substantial portion of said air stream from said abrasive particles moving in said circuitous return path after the abrasive particles have rebounded from the surface to be cleaned and are mixed with dust and debris blasted from the cleaned surface, said cleaning means causing the diverted and separated portion of the air stream to carry dust with it away from said circuitous return path and the abrasive particles moving through said circuitous path;
• said air washing improvement further including an abrasive particle curtain-developing screen positioned adjacent, and immediately upstream from, a second cleaning point in said circuitous return path, said screen being interposed in said circuitous return path of the abrasive particles for separating the abrasive particles and dust from large debris blasted from the cleaned surface by passing the abrasive particles and dust through the screen and into a gravitating abrasive particle curtain falling through said diverted and separated portion of the air stream at said second cleaning point in said circuitous return path to thereby cause the abrasive particles to undergo air washing at said second point;
• passageway means extending from said first point to said second point for conducting and directing said separated substantial portion of said air stream and entrained dust from said first point in said circuitous return path of said abrasive particles at which said separated, substantial portion of said air stream is separated from said abrasive particles, to said second point downstream in said circuitous return path at which said separated substantial portion of the air stream is directed through said gravitating abrasive particles curtain;
• dust removing means interposed in said substantial portion of said air stream downstream from said second point for removing dust from the substantial portion of said air stream after it is passed across and through said gravitating curtain of abrasive particles in said circuitous return path at said second point, said dust removing means separating dust from said substantial portion of said air stream;
• chamber means for receiving said large debris removed by said screen, and said dust removed by said dust removing means, and including an opening at the bottom of said chamber means;
• and
• auger conveyor means within the lower portion of said chamber means for receiving and then transferring dust and large debris falling downwardly in said chamber means toward said opening as said dust and large debris gravitates onto said auger conveyor means within said chamber means.

A surface blasting apparatus comprising:

• means for propelling abrasive particles against a surface to be cleaned by the scouring action of the abrasive particles impinging on such surface;
• storage hopper means for containing the abrasive particles at a location above said abrasive propelling means for gravitationally supplying abrasive particles to said abrasive particle propelling means;
• an inclined chute for receiving abrasive particles rebounding upwardly from said surface to be cleaned by abrasive particle scouring action, and for conducting the stream of rebounding abrasive particles upwardly and laterally at an angle to the vertical;
• means for inducing a flow of air into said chute for admixture with rebounding abrasive particles in said chute as the abrasive particles move upwardly and laterally in said chute;
• baffle means defining an undulating, tortuous air-flow path from the lower side of the baffle means to the upper side thereof, and positioned adjacent and above said exit at the upper end of said abrasive return chute for allowing the air mixed with the abrasive in the chute to flow upwardly therethrough through the tortuous, undulating path around portions of said baffle means, while preventing the movement of abrasive particles upwardly through said baffle means in opposition to the force of gravity exerted downwardly thereon, to thereby enable the air moving through said baffle means to scrub the abrasive particles to remove dust and debris therefrom;
• magnetic abrasive particle receiving and arresting means positioned adjacent said baffle means at a location at one side of said baffle means in a substantially vertically extending plane which extends across, and intersects, the path of upward and lateral movement of said abrasive particles in said chute after said abrasive particles have struck or passed by said baffle means, whereby a portion of the air moving upwardly in said chute with said abrasive particles will impinge against said magnetic abrasive particle receiving and arresting means, and against abrasive particles magnetically retained thereon, and whereby a portion of said abrasive particles impact said abrasive receiving and arresting means and are held thereon for subjection to a scrubbing action developed by the air moving therepast, said retained abrasive particles being removed, in substantial part, from said arresting means by impact of additional abrasive particles rebounding upwardly in said return chute, said baffle means and said magnetic particle receiving and arresting means cooperating with each other and with gravity to (a) change the directional movement of abrasive particles from upward and laterally with respect with said surface to be cleaned, to downwardly in the general direction of said surface to be cleaned, and to (b) thoroughly air scrub abrasive particles to remove dust and debris therefrom, and to entrain such removed dust and debris from the air moving upwardly through said tortuous undulating path defined by said baffle means;
• conveyor means disposed below said baffle means and below said magnetic abrasive particle receiving and arresting means for carrying abrasive particles from a location below said baffle means and magnetic abrasive particle receiving and arresting means to said abrasive storage hopper means, said conveyor means including:
• a horizontally extending conveyor portion having one end thereof beneath said baffle means and said magnetic abrasive particle receiving and arresting means for receiving abrasive particles therefrom;
• a vertically extending conveyor portion for receiving abrasive particles from said horizontally extending portion and carrying said abrasive particles upwardly to a point of discharge;
• an upper abrasive compartment spaced above said storage hopper and positioned for receiving abrasive particles from said vertically extending conveyor portion and for gravitating abrasive particles through the space between said upper abrasive compartment and said storage hopper means;
• and
• passageway means for conducting and directing air from a point of discharge from said baffle means after passage through said tortuous, undulating path, to said location where abrasive particles are gravitated from said upper abrasive compartment toward said abrasive storage hopper means whereby said gravitating abrasive particles are further cleaned by additional air scrubbing occurring at the location of such abrasive particle gravitation.

A surface blasting apparatus comprising:

• means for propelling abrasive particles against a surface to be cleaned by the scouring action of the abrasive particles impinging on such surface;
• storage hopper means for containing the abrasive particles at a location above said abrasive propelling means for gravitationally supplying abrasive particles to said abrasive particle propelling means;
• an inclined chute for receiving abrasive particles rebounding upwardly from said surface to be cleaned by abrasive particle scouring action, and for conducting the stream of rebounding abrasive particles upwardly and laterally at an angle to the vertical;
• means for inducing a flow of air into said chute for admixture with rebounding abrasive particles in said chute as the abrasive particles move upwardly and laterally in said chute;
• baffle means defining an undulating, tortuous air-flow path from the lower side of the baffle means to the upper side thereof, and positioned adjacent and above said exit at the upper end of said abrasive return chute for allowing the air mixed with the abrasive in the chute to flow upwardly therethrough through the tortuous, undulating path around portions of said baffle means, while preventing the movement of a substantial portion of said abrasive particles upwardly through said baffle means in opposition to the force of gravity exerted downwardly thereon, to thereby enable the air moving through said baffle means to scrub the abrasive particles to remove dust and debris therefrom;
• magnetic abrasive particle receiving and arresting means positioned adjacent said baffle means at a location at one side of said baffle means in an upwardly extending plane which extends across, and intersects, the path of upward and lateral movement of said abrasive particles in said chute after said abrasive particles have struck or passed by said baffle means, whereby a portion of the air moving upwardly in said chute with said abrasive particles will impinge against said magnetic abrasive particle receiving and arresting means, and against abrasive particles magnetically retained thereon, and whereby a portion of said abrasive particles impact said abrasive receiving and arresting means and are held thereon for subjection to a scrubbing action developed by the air moving therepast, said retained abrasive particles being removed, in substantial part, from said arresting means by impact of additional abrasive particles rebounding upwardly in said return chute, said baffle means and said magnetic particle receiving and arresting means cooperating with each other and with gravity to (a) change the direction of movement of abrasive particles from upward and laterally with respect with said surface to be cleaned, to downwardly in the general direction of said surface to be cleaned, and to (b) thoroughly air scrub abrasive particles to remove dust and debris therefrom, and to entrain such removed dust and debris from the air moving upwardly through said tortuous undulating path defined by said baffle means;
• an abrasive conveyor disposed, in part, below said baffle means and said return chute for receiving gravitating abrasive and carrying said abrasive to a position above said storage hopper;
• means for directing abrasive from said abrasive conveyor into said storage hopper by way, in part, of a gravitating curtain of abrasive which extends across the path of air discharged from said baffle means after flowing therethrough, whereby further removal of dust and debris from said abrasive is effected as air is moved from the baffle means to and through said gravitating curtain of abrasive;
• and
• passageway means for directing the flow of air between said baffle means and the point at which air is impinged upon abrasive in said gravitating curtain to effect said further removal of dust and debris from said abrasive.