GB1559016A

GB1559016A - Treatment of surfaces

Info

Publication number: GB1559016A
Application number: GB47251/76A
Authority: GB
Original assignee: INVEX AUSSENHANDELSGES
Current assignee: INVEX AUSSENHANDELSGES
Priority date: 1975-11-18
Filing date: 1976-11-12
Publication date: 1980-01-09
Also published as: PL113452B1; NL7612375A; ATA839076A; IT1123930B; BE848485A; SE417067B; SE7612826L; LU76202A1; DD127472A5; CH617114A5; ES453456A1; FI763309A; RO72130A; SU818470A3; JPS5262794A; CS195742B2; FI58450C; AT345690B; CA1051199A; FR2332102A1

Abstract

In order to use up the kinetic energy still contained in the liquid jet reflected from the surface of the sheet-metal strip, the latter is guided in the form of a loop, with the result that the reflected liquid jet repeatedly makes contact, along a polygonal progression, with the surface to be treated. For this purpose, the blasting nozzle is directed, at an angle of from 30 DEG to 80 DEG , onto the concave surface of the loop of the sheet-metal strip and is inclined such that the reflected liquid jet makes contact with the sheet-metal strip in regions which are located in an offset manner in the blasting direction. The process is used for removing rust and scale and for cleaning. <IMAGE>

Description

(54) IMPROVEMENTS RELATING TO THE TREATMENT OF SURFACES (71) We, INVEX AUSSENHANDEL SGESELLSCHAFT FUR MASCHINEN UND FABRIKANLAGEN MBH of Heumarkt 65, 5 Cologne 1, Federal German Republic, a German company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to a process for treating a surface by means of a jet of liquid impmgmg on the surface. Scouring or polishing solid particles are admixed with the jet. This process serves the purpose of derusting, de-scaling and cleaning of iron and steel and also of the surface treatment of plastics.In this process liquids, particularly water, are sprayed under high pressure from at least one steel nozzle on to the surface to be treated. In the nozzle polishing or scouring solid particles are admixed with the liquid jet in a dry or wet state.

The process is applicable with advantage to the treatment of sheet metal, rolled sections, tubes, wires and castings, and also to the matting of plastics surfaces. The liquid jet impinging at high velocity on the surface to be treated tears dirt, scale and rust particles, oils adhering thereto and paint off this surface. In order to enhance the abrasive effect of the liquid jet, scouring or polishing solid particles are admixed therewith. When the liquid jet impinges on the surface to be treated, the solid particles pass through the liquid film and thus become effective.

In the known process the energy consumption is relatively large. The aim of the present invention is to provide a process and apparatus with the aid of which improved energy utilisation in the course of the above-described process is made possible.

The invention provides a process for treating a surface wherein a jet of liquid with which scouring and polishing particles are admixed emerges from a nozzle at a gauge pressure of 200 to 600 bar and is directed to impinge on a portion of said surface at an angle of between 300 and 800 and, after the jet has impinged on said portion, it is at least once returned to a second portion of said surface positioned upstream of the first-named portion for treatment of said second portion so that the residual kinetic energy is utilised.

In one preferred embodiment a sheet strip is guided to form a loop and said jet impinges on a concave region of said strip within said loop so that the reflected jet impinges along a polygonal line on portions of said concave region positioned upstream of the portion of first impingement.

In another preferred embodiment the jet is returned to a second portion of said surface by means of at least one further jet emerging from a second nozzle and impinging on the reflected jet.

The invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a perspective view of an apparatus for carrying out a process according to the invention, the apparatus having an additional nozzle for diverting the jet, and Figure 2 shows a further arrangement for carrying out a process according to the invention on which the jet is diverted by the curved shape of the strip being treated.

As shown in Figures 1 and 2 a jet 4 of liquid with which scouring and polishing particles are admixed emerges from a nozzle 3 at a gauge pressure of 200 to 600 bar and is directed to impinge on a portion of a surface 1 to be treated of a sheet metal strip 2 moving in the direction of the arrow at an angle of between 300 and 800 After the jet 4 has impinged on said portion, it is returned to a second portion of said surface 1, positioned upstream of the first-named portion, for treatment of said second portion by being diverted bv a jet 28 from an additional nozzle 25. In this embodiment the nozzle 3 is of elongate cross-section. The reflected jet 4 is discharged upwardly to the left in Figure 1, is intersected by the jet 28 from the additional nozzle 25, thereby changing its direction and inpinges on the surface 1 for the second time in the form of a jet 9.

The jet 28 from the additional nozzle 25 is preferably a liquid jet without solid particles, the same liquid being used as that for the nozzle 3. The jet 28 may, however, also be a compressed air jet or a jet of a second liquid, which may also contain solid particles.

The additional nozzle 25 is arcuate in cross-section. This is intended to have the effect of the jet which diverges after iS impact on the surface I being reunited.

The additional nozzle generally subtends a different angle to the surface 1 from that of the nozzle 3. The desired inclination may for example be determined by a setting device 26, 27.

In Figure 2 the treatment of a sheet metal strip 2 is shown which moves in the direction of the arrow and is conducted in th the form of a loop by means of rollers 37, 38 and other devices (not shown) so that a concave inner space is formed. The jet medium 4 is sprayed into this inner space by the nozzle 3. The jet medium impinges on the surface 1 to be treated in such a way that, after reflection, it again impinges on the surface 1 to be treated. After several reflections, during which the jet medium travels along a polygonal line and impinges on a succession of portions of said concave region, the jet medium flows along the surface and flows away below the roller 37.

This flow along the concavely curved area of the sheet metal strip 2 has the effect that the heavier solid particles are accelerated by a centrifugal effect onto the surface 1 to be treated and flow therealong. For the purpose of descaling a sheet steel strip a loop formation may simultaneously also serve the purpose of tearing open the scale layers on the sheet metal strip.

The particles admixed to the jet 4 may be steel granules and/or corundum and/or sand andior chalk.

WHAT WE CLAIM IS: 1. A process for treating a surface wherein a jet of liquid with which scouring and polishing particles are admixed emerges from a nozzle at a gauge pressure of 200 to 600 bar and is directed to impinge on a portion of said surface at an angle between 300 and 800 and, after the jet has impined on said portion, it is at least once returned to a second portion of said surface positioned upstream of the first-named portion for treatment of said second portion so that the residual kinetic energy is utilised.

2. A process according to Claim 1 for treating a surface of a sheet, wherein the sheet strip is guided to form a loop and said jet impinges on a concave region of said strip withm said loop so that the reflected jet impinges along a polygonal line on portions of said concave region positioned upstream of first impingement.

3. A process according to Claim 1 or 2 wherein said jet is returned to a second portion of said surface by means of at least one further jet emerging from a second nozzle and impinging on the reflected jet.

4. A process according to Claim 3 wherein the second nozzle is arcuate in cross-section.

5. A process according to Claim 3 or 4 wherein the or or each further jet is directed to the surface at an angle different from that of the first-mentioned jet.

6. A process according to any one of Claims 1 to 5 wherein said solid particles are steel granules and/or corundum and/or sand and/or chalk.

7. A process for treating a surface according to Claim 1 substantially as herein described with reference to the accompanying drawings.

8. An article having a surface which has been treated by a process according to any one of Claims 1 to 7.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. surface 1, positioned upstream of the first-named portion, for treatment of said second portion by being diverted bv a jet 28 from an additional nozzle 25. In this embodiment the nozzle 3 is of elongate cross-section. The reflected jet 4 is discharged upwardly to the left in Figure 1, is intersected by the jet 28 from the additional nozzle 25, thereby changing its direction and inpinges on the surface 1 for the second time in the form of a jet 9. The jet 28 from the additional nozzle 25 is preferably a liquid jet without solid particles, the same liquid being used as that for the nozzle 3. The jet 28 may, however, also be a compressed air jet or a jet of a second liquid, which may also contain solid particles. The additional nozzle 25 is arcuate in cross-section. This is intended to have the effect of the jet which diverges after iS impact on the surface I being reunited. The additional nozzle generally subtends a different angle to the surface 1 from that of the nozzle 3. The desired inclination may for example be determined by a setting device 26, 27. In Figure 2 the treatment of a sheet metal strip 2 is shown which moves in the direction of the arrow and is conducted in th the form of a loop by means of rollers 37, 38 and other devices (not shown) so that a concave inner space is formed. The jet medium 4 is sprayed into this inner space by the nozzle 3. The jet medium impinges on the surface 1 to be treated in such a way that, after reflection, it again impinges on the surface 1 to be treated. After several reflections, during which the jet medium travels along a polygonal line and impinges on a succession of portions of said concave region, the jet medium flows along the surface and flows away below the roller 37. This flow along the concavely curved area of the sheet metal strip 2 has the effect that the heavier solid particles are accelerated by a centrifugal effect onto the surface 1 to be treated and flow therealong. For the purpose of descaling a sheet steel strip a loop formation may simultaneously also serve the purpose of tearing open the scale layers on the sheet metal strip. The particles admixed to the jet 4 may be steel granules and/or corundum and/or sand andior chalk. WHAT WE CLAIM IS:

1. A process for treating a surface wherein a jet of liquid with which scouring and polishing particles are admixed emerges from a nozzle at a gauge pressure of 200 to 600 bar and is directed to impinge on a portion of said surface at an angle between 300 and 800 and, after the jet has impined on said portion, it is at least once returned to a second portion of said surface positioned upstream of the first-named portion for treatment of said second portion so that the residual kinetic energy is utilised.