EP0672502A1 - Vorrichtung zur Anwendung von Strahlmittel an Gegenständen - Google Patents

Vorrichtung zur Anwendung von Strahlmittel an Gegenständen Download PDF

Info

Publication number
EP0672502A1
EP0672502A1 EP95301507A EP95301507A EP0672502A1 EP 0672502 A1 EP0672502 A1 EP 0672502A1 EP 95301507 A EP95301507 A EP 95301507A EP 95301507 A EP95301507 A EP 95301507A EP 0672502 A1 EP0672502 A1 EP 0672502A1
Authority
EP
European Patent Office
Prior art keywords
blast media
channel
supply means
outlet
application head
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP95301507A
Other languages
English (en)
French (fr)
Inventor
Anthony Peter Broadbent Maufe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guyson International Ltd
Original Assignee
Guyson International Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Guyson International Ltd filed Critical Guyson International Ltd
Publication of EP0672502A1 publication Critical patent/EP0672502A1/de
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24C—ABRASIVE OR RELATED BLASTING WITH PARTICULATE MATERIAL
    • B24C5/00—Devices or accessories for generating abrasive blasts
    • B24C5/02—Blast guns, e.g. for generating high velocity abrasive fluid jets for cutting materials
    • B24C5/04—Nozzles therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24C—ABRASIVE OR RELATED BLASTING WITH PARTICULATE MATERIAL
    • B24C5/00—Devices or accessories for generating abrasive blasts
    • B24C5/02—Blast guns, e.g. for generating high velocity abrasive fluid jets for cutting materials

Definitions

  • the present invention relates to apparatus for emitting blast media onto an article in such a manner that the surface of the article is cleaned or coatings on the article are removed due to the abrasive effect of the blast media.
  • the apparatus can also be used to emit blast media to allow a surface to be prepared for subsequent application of coatings such as paint or plastics or cosmetic finishes.
  • the first method is by the impacting of a slurry of blast material on the article and the second is by impacting dry blast media onto the article.
  • This invention is primarily concerned with the second of the two methods, namely the dry blasting method.
  • the most common method of applying the blast media in a dry blasting process is to use a pressurised fluid such as a supply of compressed air to pick up the blast media and accelerate the same in the compressed air supply onto the surface through an application head.
  • a pressurised fluid such as a supply of compressed air
  • the application head through which the blast media is accelerated onto the surface includes a compressed air supply which enters the application head substantially along the longitudinal axis of the head. There is also provided a supply of blast media which enters the application head downstream of the air supply and at a tangent to the path of the air supply.
  • the compressed air in the application head passes through a small diameter orifice into a larger diameter nozzle and this creates a vacuum within the head which is used to draw up the blast media, so that blast media is ejected from the nozzle.
  • the second method is a more complex method and involves a larger number of parts including a pressure vessel in which the blast media is held under pressure.
  • the blast media is released into a flow of compressed air and, as the media is held under pressure, the acceleration of the media is substantially greater than that in the first method and typically the acceleration obtained is four times greater.
  • this method provides improved results over the suction feed method the system is much more expensive due to the cost of manufacture of the parts to meet the relevant safety standards and the high maintenance costs of the apparatus.
  • the acceleration achieved is significantly higher the application of blast media onto the surface by this method produces an improved keyed surface such that, for some surfaces, only the second method can currently be used to produce the required quality of coating on the surface.
  • a further known problem with application heads which are the subject of previous patent applications is that problems occur when the same are provided to be adjustable in that the space between the blast media supply means outlet and the channel walls, which is typically annular and through which the pressurised fluid is supplied, is adjustable to allow the velocity of the pressurised fluid to be adjusted.
  • the adjustment is achieved by the provision of a screw thread arrangement between the blast media supply means and a holder which allows the position of the outlet of the blast media supply means to be adjusted by a screwing or unscrewing action relative to the channel to allow the adjustment of the annular space between the outlet and the channel wall.
  • the problem with this adjustment method and all other known methods is that the position of the blast media outlet relative to the channel is not maintained in a concentric position with the channel in each of the various positions.
  • the aim of the present invention is to provide an improved application head for the application of blast media using a suction feed method which achieves levels of acceleration and evenness of treatment and hence surface keying means approaching those achieved by using the pressurised media feed method.
  • apparatus for applying blast media to a surface including a pressurised fluid supply, a blast media supply and an application head, said application head comprising a channel with an outlet through which the blast media is applied and a first inlet for the supply of blast media and the blast media enters the head substantially in line with said channel and the pressurised fluid passes into a substantially annular passage defined between the channel and the blast media supply means and characterised in that at least a portion of the channel wall is radiussed inwardly to reduce the cross sectional size of the channel.
  • the radiussed portion is positioned adjacent the outlet of the blast media supply means.
  • the channel cross sectional area is reduced at a point intermediate the outlet of the blast media supply means and the outlet of the channel.
  • the radius is convex.
  • the present invention provides apparatus for applying blast media to a surface, said apparatus including a pressurised fluid supply, a blast media supply and an application head, said application head comprising a channel with an outlet through which the blast media is applied and a first inlet for the supply of pressurised fluid and a second inlet for the supply of blast media and the blast media enters the head substantially in-line with said channel and characterised in that there is provided on the interior of the channel a series of protrusions with which the blast media supply means contacts and is maintained in a substantially concentric position within the channel.
  • the channel preferably passes along the longitudinal axis of the application head and the blast media is introduced into the channel along the longitudinal axis.
  • the pressurised fluid is compressed air and is introduced into the application head also in line with the channel such that the compressed air passes around the periphery of the outlet of the blast media supply means.
  • the compressed air passes through an annular passage, and the blast media supply means defines the inner body of the same.
  • the area of the annular compressed air supply is reduced as it approaches the introduction point for the blast media.
  • the cross section of the media supply means is reduced in cross sectional area prior to the introduction of the media into the application head to produce a throttling effect on the supply.
  • the linear protrusions on the channel wall are ribs which are disposed in parallel with the longitudinal axis of the channel and the ribs are spaced around the channel wall.
  • the position of the outlet of the blast media media supply means relative to the channel is adjustable to allow the annular space between the blast media outlet and the channel wall between which the pressurised fluid passes to be adjusted.
  • the adjustment of the annular space alters the speed of the pressurised fluid into the channel and hence the velocity of the blast media when leaving the application head.
  • the length of the linear protrusions is such as to ensure that the blast media supply means contacts the same in whichever position the same is adjusted thereby maintaining the same in a concentric position with the channel walls.
  • At least a portion of the wall of the channel is radiussed inwardly adjacent the outlet of the blast media supply means to reduce the diameter of the same at a point between the introduction of the blast media and the channel outlet.
  • the radii are convex.
  • the application head comprises two assemblies, a first assembly which includes the outlet and part of the channel and a removable second assembly which includes connections to both the compressed air supply and blast media supply and the remainder of the channel.
  • the first assembly is provided with the channel in the form of a nozzle shaped to provide optimum discharge of the blast media.
  • the application head is provided with a removable handle and/or clamp means to enable ease of holding the same and preferably the application head has the external shape of a conventional suction feed application head.
  • the application head is formed from aluminium, polyurethane or a metal alloy to allow the same to be relatively light with the channel of the gun, and, if necessary the blast media and/or compressed air supply means, lined or coated with a hard wearing material such as tungsten, boron, carbide or ceramics to improve the life of the components against wear from the blast media as it is accelerated therethrough.
  • a hard wearing material such as tungsten, boron, carbide or ceramics
  • blast media used will be any suitable media but preferably one of grains of aluminium oxide, carbon steel, brass or glass.
  • an application head through which blast media can be applied to treat a surface
  • said application head comprising a longitudinal channel with an outlet through which the blast media are emitted, blast media supply means having an outlet mounted within the channel and defining between the blast media supply means and the channel wall a substantially annular passage through which a pressurised fluid enters the channel to induce the media through the channel toward the outlet and characterised in that at a position removed from the blast media supply means outlet a locating ring is provided and the position of said blast media supply means is adjustable relative to the channel by the selective positioning of a plurality of movable positioning means relative to the locating ring.
  • the channel wall is provided with a location means in the form of a stepped portion against which abuts the locating ring and, if so positioned, at least one of the positioning means.
  • the stepped portion is provided as part of an indented portion around the channel wall and which is of a width to accomodate the locating ring and the positioning means.
  • the position of the outlet of the blast media supply means relative to the channel is determined by the position of the locating ring in the channel location means.
  • several positioning means are provided and the outlet is in front position hence providing the closest annular space between the channel wall and the outlet when the positioning means are at the rear of the locating ring, the outlet is then moved back to intermediate positions by the placing of one and two positioning means respectively in front of the locating ring in the channel location means and finally can be moved to a position where the space is at a maximum size when positioning means are moved to the front of the locating ring.
  • the movable positioning means are washers mounted on the blast media supply means and which can be moved to lie on either side of the locating ring which is provided in a permanently fixed position.
  • the channel wall is provided with a plurality of ribs therearound to maintain the outlet of the blast media supply means in a concentric position in the channel in each adjusted position.
  • Fig. 1 there is illustrated the contrast between a typical surface finish 2 provided by a suction feed apparatus for applying blast media and the surface finish 4 obtained by applying the blast media using a pressurised system.
  • the surface finish obtained by using the pressurised system includes substantially deeper keying recesses 6 than the recesses 8 achieved by using the suction feed method.
  • the ability to provide deeper keying recesses on the surface allows the subsequent coating applied thereto to adhere more firmly by filling in the deeper recesses 6 and thereby allowing substantially stronger coating to surface bonds to be achieved than by using the suction feed apparatus.
  • Fig. 2 illustrates a cross section through a conventional application head 10 for use in applying blast media 12 to the surface 2. Also shown is the method of supply and mixing of the blast media and compressed air which carries the media through the application head.
  • the blast media 12 is introduced into the application head 10 via pipe 14 and the compressed air is introduced via pipe 16.
  • the compressed air is introduced in line with channel 18 such that the compressed air flows through the application head relatively undisturbed.
  • the blast media 12 are drawn into the flow of the compressed air from the supply pipe 14 which is arranged to enter the channel 18 at a tangent to the flow of the compressed air.
  • the blast media is drawn into the compressed air flow so the speed of the same is accelerated to a speed to cause an impact effect on the surface 2.
  • the surface effect obtained is not as good as the pressurised feed system and this is largely due to the fact that the appliction head of Fig. 2 does not allow the blast media to be accelerated to a sufficient velocity to have any greater impact on the surface 2.
  • Fig. 3 illustrates a cross sectional elevation of an application head according to one aspect of the invention which allows the blast media therein to be accelerated to a greater extent than in the conventional application head of Fig. 2.
  • the application head 20 comprises a compressed air supply 22 and a blast media supply 24 and both the supplies 22 and 24 are positioned to introduce material into the channel 26.
  • the channel has at one end an outlet 28 through which the accelerated blast media leaves the application head 20 and at the other end 30 has a chamber 32 which defines the point at which the blast media comes under the influence of the compressed air.
  • the blast media supply 24 is arranged to introduce the blast media into the chamber in line with the channel 26.
  • the compressed air supply is arranged to introduce compressed air into the chamber 32 at a point to the rear of the outlet 33 of the blast media supply 24 such that the compressed air is forced toward the channel 26 through the chamber 32.
  • the chamber includes an annular passage 34 the cross sectional area of which is reduced to the smallest area where the blast media is supplied into the chamber 32. As shown the blast media supply pipe 24 is arranged in the chamber such that it forms the inner body of the annular passage 34.
  • the blast media is induced into the compressed air stream which continues into the channel 26 to the outlet 28.
  • a reducer 36 which is provided with radiussed walls which are convexly shaped, one such convex shape is to have the walls radiussed to 50mm, but this is only one example.
  • the effect of radiussing these walls is to cause the desired annular air flow and hence reduce the turbulence which is created and hence increase the velocity of the blast media in comparison with the conventional application head such as that shown in Figure 2.
  • the improvement in velocity and reduction in turbulence results in an improved average velocity across the spread of the blast media emitting from the application head which results in better coverage, better impact and a more consistent finish.
  • Figures 4,5 and 6 illustrate a second aspect of an application head of the invention which includes the feature of the radiussed channel wall portion 101 as in Figure 3 but illustrates an application head with further inventive features.
  • the application head 102 comprises a body 104 which is provided with a handle 106 by which the same can be held. Passing along the longitudunal axis of the body 104 there is provided a channel 108 into which protrudes the outlet 110 of a blast media supply means 112 which in turn is connected to a blast media supply pipe 114 which enters the application head from the rear 116.
  • a pressurised fluid in the form of compressed air is supplied from compressed air supply means 122 which also is connected into the rear of the application head.
  • the pressurised fluid is introduced into the channel upstream from the outlet 110 of the blast media supply means and passes through an annular passage 124 defined between the channel wall and the blast media supply means 112. As the pressurised fluid passes through the space 124 it acts to pick up the blast media from the outlet 110 and accelerate the same to be emitted from the channel outlet 118.
  • the radiussed channel wall portion 101 is provided as discussed and also a series of linear protrusions in the form of ribs 130 are provided at spaced intervals around the channel 108 in a position such that the blast media supply means 112 contacts the same and is thus held in a position which is concentric with the channel 108.
  • This ability to position the blast media supply means 112 in a concentric position relative to the channel 108 has been found to improve the flow of blast media through the channel 108.
  • the ability to maintain the blast media supply means in a concentric position is also required when, as in the embodiment shown in Figures 4,5 and 6, the position of the outlet 110 of the blast media supply means 112 is adjustable to alter the size of the annular space 124 and hence adjust the speed of the pressurised fluid and subsequently the blast media from the application head.
  • the provision of the ribs 130 ensure that the concentric position of the blast media supply means is maintained. Also shown are the coatings 133 on the channel 108 of hard wearing material to reduce erosion of the same due to the blast media.
  • the same is provided with a fixed locating ring 132 and a plurality of movable positioning means 134 which, in combination, are locatable in a locating indent 136 formed in the channel 108.
  • the components of the application head of Figures 4, 5 and 6 are illustrated in more detail in Figures 7A-7D and the same reference numerals are used to indicate the various component parts.
  • the number of positioning means 134 which are placed on either side of the locating ring 132 determine the position of the same relative to the locating indent 136 in the channel and hence the position of the outlet 110 of the blast media supply means 112 can be determined and adjusted to allow alteration of the blast media characteristics while the provision of the ribs 130 with which th blast media supply means 112 contacts, in whichever position, allows the same to be maintained in a concentric position relationship with the channel 108.
  • Figures 7C and 7D illustrate a handle 106 which can be fitted to the application head to allow the same to be hand held and a clamping means 140 which can be fitted in substitution for the handle 106 to allow the application head to be maintained in a fixed position.
  • the application head incorporating any one, or any combination of, the features described herein represents significant improvements in the quality of control of the blast media emitted from the same and allows a uniform pattern of blast media emission to be achieved and at the same time allows improved large area finishing quality to be improved with the substantial elimination of the striping effect achieved which is of particular advantage with regards to the tratment of surfaces for cosmetic purposes such as glass bottles, perfume botles and also when treating surfaces for keying a coating thereto the keying effect which can be achieved is improved.
  • the ability to adjust the position of the blast media supply means in the channel of the application head in the manner described allows adjustment of the blast media emission characteristics to be achieved whilst maintaining the quality of the same.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Spray Control Apparatus (AREA)
EP95301507A 1994-03-11 1995-03-08 Vorrichtung zur Anwendung von Strahlmittel an Gegenständen Withdrawn EP0672502A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9404763 1994-03-11
GB9404763A GB9404763D0 (en) 1994-03-11 1994-03-11 An application head for emitting blast media

Publications (1)

Publication Number Publication Date
EP0672502A1 true EP0672502A1 (de) 1995-09-20

Family

ID=10751695

Family Applications (1)

Application Number Title Priority Date Filing Date
EP95301507A Withdrawn EP0672502A1 (de) 1994-03-11 1995-03-08 Vorrichtung zur Anwendung von Strahlmittel an Gegenständen

Country Status (2)

Country Link
EP (1) EP0672502A1 (de)
GB (1) GB9404763D0 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003022525A2 (de) * 2001-09-11 2003-03-20 Jens Werner Kipp Strahlverfahren und -vorrichtung

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE494888C (de) * 1928-08-31 1930-03-29 Alfred Gutmann A G Fuer Maschb Ringspaltduese fuer Sandstrahlgeblaese
US2878624A (en) * 1957-03-04 1959-03-24 Hastrup Herman Surface contactor for blast cleaning machine
US4080762A (en) * 1976-08-26 1978-03-28 Watson John D Fluid-abrasive nozzle device
DE2706525A1 (de) * 1977-02-16 1978-08-17 Peiniger Ernst Gmbh Strahlgeraet fuer das druckluftstrahlen
DE8606183U1 (de) * 1986-03-06 1986-06-12 Bauer, Josef, 21224 Rosengarten Naßstrahlvorrichtung
AU553658B2 (en) * 1983-04-27 1986-07-24 Bolrette Pty. Ltd. Abrasive blasting apparatus
WO1988004220A1 (en) * 1986-12-03 1988-06-16 K.G. McCOLL & COMPANY LIMITED Method and apparatus for wet abrasive blasting
US4815241A (en) * 1986-11-24 1989-03-28 Whitemetal Inc. Wet jet blast nozzle
DE4120613A1 (de) * 1991-06-20 1992-03-05 Suesse Harald Selbstregulierender hochdrucktrennstrahlbeschleuniger
DE4127886A1 (de) * 1991-08-22 1993-02-25 Abrex Oberflaechentechnik Gmbh Strahlkopf fuer hochdruck-sandstrahlanlagen
DE9307454U1 (de) * 1993-05-17 1993-10-21 Rath Dieter Strahldüse
EP0573957A1 (de) * 1992-06-09 1993-12-15 Günter Max Raml Vorrichtung zur Strahlbearbeitung von Materialien

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE494888C (de) * 1928-08-31 1930-03-29 Alfred Gutmann A G Fuer Maschb Ringspaltduese fuer Sandstrahlgeblaese
US2878624A (en) * 1957-03-04 1959-03-24 Hastrup Herman Surface contactor for blast cleaning machine
US4080762A (en) * 1976-08-26 1978-03-28 Watson John D Fluid-abrasive nozzle device
DE2706525A1 (de) * 1977-02-16 1978-08-17 Peiniger Ernst Gmbh Strahlgeraet fuer das druckluftstrahlen
AU553658B2 (en) * 1983-04-27 1986-07-24 Bolrette Pty. Ltd. Abrasive blasting apparatus
DE8606183U1 (de) * 1986-03-06 1986-06-12 Bauer, Josef, 21224 Rosengarten Naßstrahlvorrichtung
US4815241A (en) * 1986-11-24 1989-03-28 Whitemetal Inc. Wet jet blast nozzle
WO1988004220A1 (en) * 1986-12-03 1988-06-16 K.G. McCOLL & COMPANY LIMITED Method and apparatus for wet abrasive blasting
DE4120613A1 (de) * 1991-06-20 1992-03-05 Suesse Harald Selbstregulierender hochdrucktrennstrahlbeschleuniger
DE4127886A1 (de) * 1991-08-22 1993-02-25 Abrex Oberflaechentechnik Gmbh Strahlkopf fuer hochdruck-sandstrahlanlagen
EP0573957A1 (de) * 1992-06-09 1993-12-15 Günter Max Raml Vorrichtung zur Strahlbearbeitung von Materialien
DE9307454U1 (de) * 1993-05-17 1993-10-21 Rath Dieter Strahldüse

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003022525A2 (de) * 2001-09-11 2003-03-20 Jens Werner Kipp Strahlverfahren und -vorrichtung
WO2003022525A3 (de) * 2001-09-11 2003-09-12 Jens Werner Kipp Strahlverfahren und -vorrichtung

Also Published As

Publication number Publication date
GB9404763D0 (en) 1994-04-27

Similar Documents

Publication Publication Date Title
US6293857B1 (en) Blast nozzle
US4618101A (en) Spray nozzle
US5487695A (en) Blast nozzle combined with multiple tip water atomizer
CA2701185C (en) Method and apparatus for prepping a surface using a coating particle entrained in a pulsed waterjet or airjet
TW333489B (en) Blasting method and apparatus
US4232824A (en) Method and apparatus for the pneumatic spraying of liquid products
US6431464B2 (en) Thermal spraying method and apparatus
US4715535A (en) Powder spray gun
US20080017734A1 (en) System and method of uniform spray coating
US20090008469A1 (en) Spray device having a parabolic flow surface
MX2007003396A (es) Tobera para nieve/cristales de co2.
HU218517B (hu) Berendezés érzékeny, sérülékeny felületek, különösen szobrok kezelésére, tisztítására
US5169070A (en) Air directing ring for fluid spray gun air cap
US5799875A (en) HVLP spray gun and integrated fluid nozzle therefor
JP7412416B2 (ja) 材料を表面処理するための装置および方法
US6863229B1 (en) Spray head
GB2081605A (en) Spray nozzle
US7125317B2 (en) Multi-port sandblasting manifold and method
EP0672502A1 (de) Vorrichtung zur Anwendung von Strahlmittel an Gegenständen
US7500298B2 (en) Blast head for loosening or removing scale on a metal surface
CN112105483B (zh) 用于为表面消光的装置以及方法
EP0621078A1 (de) Pulverpumpe
CA2202922C (en) Rotary atomizing electrostatic coating apparatus
US20050198794A1 (en) Apparatus for the descaling of metal
JPS61241067A (ja) 乾式ブラスト装置

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE

17P Request for examination filed

Effective date: 19951124

17Q First examination report despatched

Effective date: 19970417

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19970828