WO1997009152A1

WO1997009152A1 - Abrasive jet projection nozzles

Info

Publication number: WO1997009152A1
Application number: PCT/ES1996/000167
Authority: WO
Inventors: Teodoro San Jose Aguilar
Original assignee: Teodoro San Jose Aguilar
Priority date: 1995-09-08
Filing date: 1996-09-05
Publication date: 1997-03-13

Abstract

Projection nozzles for abrasive wet or dry jet, for high or low pressure machines and operating in cold or hot conditions, comprised of two hollow and symmetrical cylinders (1-2) (fig. 3), the internal cylinder (1) being made of alumina (AL2O3) covered by the external cylinder (2) of plastic material. There is provided on said external cylinder a groove (4) for fixing to the projection lance and a truncated area (3) for enhancing the sand absorption effect. The sand enters through (3), goes through (1) and comes out through (5). The improvements introduced in the main patent P9501760 dated September 8 1995 to said nozzles comprise the modification of the hollow external cylinders (2) (fig. 5), forming the truncated zone (3) as a new part and made of a material which is different from the material of the internal cylinder (1), and from the new external cylinder (2). Materials with a different ratio prize/hardeness are used in order to reduce the price of the nozzle and to obtain an optimum hours of work/price of nozzle ratio. Alumina is used for ultra high ratio hardeness/price. The internal cylinder can also be made of tungsten or boron carbide, the external cylinder can be made of resin, fiber, polyurethane, rubber, metal, etc. The truncated area in the new part is made of alumina. Said nozzles are intended to be used in industrial cleaning applications, particularly for cleaning boat hulls, made either of metal or polyester.

Description

PROJECTION NOZZLES FOR ABRASIVE JET.

Currently there are abrasive blasting machines that project wet or dry sand under pressure, clean and pickle ε on any type of concrete, polyester, metal, etc., which makes them optimal for cleaning ship hulls.

This effective system that has the Benturi effect for sand absorption that can be projected at more than 200 bar. Pressure has a big problem in the terrible abrasion wear suffered by the nozzles where the sand is projected, since the working hour-price nozzle ratio is currently low. The following inventions come to solve this problem.

Two solutions to this problem are known: The first one uses a mouthpiece made entirely of Boron Carbide, which although it has a remarkable duration in working hours, instead its price is so high that the hour-to-work price nozzle ratio is too short. The second option manufactures the nozzle entirely in a piece of Stainless Steel, although this nozzle has a lower cost, it also has a short duration, so that the working time-price ratio is very low.

The present invention relates to a new nozzle design or prototype for wet or dry sandblasting devices, for high and low pressure machines, and cold or heat work. The main problem we face is to make the nozzle at a very low price, and with many hours of work. This cannot be achieved if we manufacture the entire nozzle of a material of extreme hardness since we find that both the material and the technology necessary to give it the complex shapes it requires are very expensive, hence the main technical innovation of this patent is break down the nozzle in a minimum of two parts, one of them of a very great abrasion wear hardness with a very simple shape that allows a cheap manufacturing cost, and on the other hand a second or more pieces where complex shapes appear (clamping grooves , areas to reinforce the effect of sand absorption, etc.) made of a material whose technology allows to manufacture complex shapes at a very cheap price as with plastics for example. This achieves a very high working hour-price nozzle ratio in relation to what is now on the market.

The other important technical characteristic is to use for the part that supports the wear by abrasion ALUMINA (AL¿Oj), this material is of a very high hardness to the abrasion and its price of manufacture for simple pieces is reduced.

Based on the attached drawings, we will now describe methodically the nozzle object of this patent: It is composed of two hollow cylinders and totally symmetrical with respect to its longitudinal axis (as it appears in the drawings), the inner cylinder (l), (Fig-1) is made of a very hard material to abrasion (Boron Carbide, Tungsten Carbide, Alumina, Stainless Steel, etc.), through which wet or dry sand is projected, hence the need to Its great hardness. This cylinder (1) is covered by another hollow cylinder (2) (Fig-2, Fig-3), both being strongly bonded by heat and pressure, fully guaranteeing the union of the two cylinders and preventing any slippage between them. This cylinder (2), (Fig-2), is the one with the complex shapes: A groove (4) that completely surrounds it and serves to fix or attach the nozzle to the lance or spray gun of the sand, and a conical trunk shape (3) fundamental to favor the absorption effect of wet or dry sand, this sand is absorbed in (3), passes through the cylinder (1) and is projected through the area (5). This external cylinder (2) is made of a material whose technology and raw material allows it to be manufactured with complex shapes (3-4) at a very very low cost, so it has been thought to use plastic, fiber, resin, cheap metal, etc. . In this way a nozzle (Fig-3) is obtained, which absorbs sand through the area (3), passes it through the cylinder (1) and projects it out through the area (5), being subject to the lance or pistol of projection through the groove (4). This nozzle has a very low manufacturing price and a great duration which gives us a very high working time-price nozzle ratio.

The optimal embodiment would be: The inner cylinder (1) made of ALUMINA and the outer cylinder (2) of plastic.

DESCRIPTION OF THE DRAWINGS. Figure 1.- Shows in elevation, plan and section the symmetrical cylinder (1) that constitutes the simplest and hardest internal part of the nozzle.

Figure 2.- Shows in elevation, plan and section the symmetrical cylinder (2) that constitutes the stern part of the nozzle, in it there is a clamping groove (4) and an internal trunk-conical shape (3) for the effect of sand absorption.

Figure 3.- Shows a section or section of the complete nozzle, formed by the two cylinders (1-2), where you can easily see how the inner cylinder (1) is embedded in the outer cylinder (2), being able to see the shape conical trunk (3) and the external groove (4). IMPROVEMENTS INTRODUCED IN THE MAIN PATENT P9501760 of DATE 8 of SEPTEMBER 1,995, IN THE NOZZLES FOR DEJECTION PROJECTIONS OF SAND JET IN HUMID AND DRY, FOR HIGH OR LOW PRESSURE MACHINES AND WORK IN COLD OR CAL.

As already stated in the MAIN PATENT, this invention is for application in abrasive blasting equipment either wet (liquid abrasive) or dry (air abrasive). They are used in industrial cleaning of all types of surfaces, steel in ships, concrete in buildings, etc.

The nozzles that until now there are in the market are of one part or two parts: a shirt or housing attached to a nozzle holder and a core that in all cases joins the two areas through which the abrasive passes; the conical-trunk narrowing and the outlet tube, which are of a single piece and of a material of extreme hardness to abrasion wear.

The change that was raised in the MAIN PATENT is to create a housing of softer and cheaper material to work where both the nozzle holder system and the trunk-conical shape where the abrasive is channeled. Then it carries another hollow cylinder that is the one that really supports abrasion wear. This achieves a very good working hours / nozzle price ratio, by suppressing the trunk-conical area of a very hard and expensive material to machine.

With the improvement that is presented in this ADDICTION, we make a modification in the external cylinder or housing of the MAIN PATENT, now instead of a piece there are two: one for the trunk-conical shape that will be made in ALUMINA (t¿ Ox,) or other material, but of less hardness than the inner cylinder, and the other part will be a cylinder with the nozzle fixing elements to the nozzle holder, with this we obtain a solution for those abrasives such as copper, iron shot, which start while eroding. What is still maintained as an exclusive novelty is to separate and make the internal exit cylinder in different materials, of a material of extreme hardness and on the other hand the trunk-conical shape that will always be of a cheap machining material, maintaining the excellent relationship working hours / nozzle price. We use ALUMINA (/ 4 ¿O3) for its fantastic hardness / price ratio.

For a better understanding of how the complete nozzle would be, Figure 5 is presented, where the internal cylinder (1) of great hardness, the new housing (2) and the trunk-conical piece (3) appear.

The description of the accompanying drawings is as follows:

Figure 5.- Shows in section the complete nozzle with the new housing (2), the new trunk-conical part (3), the internal cylinder of great hardness (1) and the clamping systems (4).

Figure 6.- Shows in elevation, plan and section the new trunk-conical piece (3) that concentrates the abrasive and improves the absorption effect. Figure 4 .- Shows in elevation, plan and section the symmetrical cylinder (2) that constitutes the new housing where the fastening systems (4) are located.

An optimal way of carrying out the improvement introduced is: The external cylinder (2) made of Nylon or resin and the new trunk-conical part (3) made of ALUMINA (/ \ L _t 0 _i ) sintered.

Claims

CLAIMS.

The property and exclusive exploitation of: 1.- The projection nozzles for wet or dry abrasive blasting, for high and low pressure machines, for cold or hot work, composed of two parts, are claimed as new and own invention. a hollow cylinder of Boron Carbide, Tungsten Carbide, ALUMINUM (AL ^ O ^), stainless steel, or any other hard material, which supports abrasion wear of wet or dry sand and a second hollow cylinder of material plastic, resin, fiber, rubber, metal, which covers the inner cylinder and is attached to it forming a single body without the possibility of sliding between them. The external cylinder has a groove for attaching the nozzle to the lance or spray gun of the sand, and a trunk-conical area to facilitate the effect of sand absorption.

2. The nozzle constituted according to claim 1, which is totally or partially made of ALUMINA (AL _¿ 0 ₃ in any proportion, density or percentage, as well as any of its derivatives or physical or chemical compounds.

3.- Improvements introduced in the main PATENT P9501760 dated September 8, 1995, in the nozzles for wet or dry sandblasting devices, for high and low pressure machines, in cold or hot, consistent work in transforming the hollow outer cylinder of the MAIN PATENT into two pieces, a conical trunk (3) that reinforces the absorption effect and agglutinates the abrasive, and another piece that would be an external cylinder (2) that supports the fastening systems ( 4) from nozzle to nozzle holder. (Fig. 4-5-6).

4.- The exclusive use of sintered ALUMINUM or not, in the manufacture of all types of abrasive blasting systems (also called blasters), both wet (abrasive with liquid), such as dry (abrasive with air), for high or low pressure, cold or heat. And especially its use in any type of nozzle for these abrasive projection systems (sand, copper shot, etc.).