RU200116U1 - Steam abrasive blasting nozzle - Google Patents

Abstract

The utility model relates to abrasive blasting and is intended for use in devices for abrasive blasting of surfaces of a wide class of parts and structures. The nozzle contains a mixing chamber, in the body of which an ejection channel is installed for supplying an abrasive-gas mixture. The channel is made in the form of a Laval nozzle. A channel for supplying superheated steam is also installed in the body. The axes of the channels intersect at an acute angle inside the mixing chamber. The fitting of the channel for supplying steam is made with the possibility of axial movement and fixation, ensuring the installation of the cut at a level closer or further from the cut of the channel for supplying the abrasive-gas mixture. The result is increased efficiency of abrasive blasting with additional steam. 1 wp f-ly, 1 dwg

Description

Technology area

The utility model relates to abrasive blasting and is intended for use in devices for abrasive blasting of surfaces of a wide class of parts and structures.

State of the art

Known nozzle sandblasting apparatus [RF Patent No. 2360782, publ. 10.11.2007], containing a housing with an insert in the form of a cylindrical spring and a guide channel made in its section, and nozzles for supplying abrasive and compressed air to the guide channel. The guide channel is made conical, tapering towards its outlet section. A bushing with holes is installed in the body axisymmetrically to the guide channel, connecting the guide channel with nozzles for supplying abrasive and compressed air. The holes connecting the pipe for supplying compressed air and the cavity between the insert and the wall of the guide channel are made along a helical line relative to the axis of the guide channel.

The disadvantage of this design is that only a two-component gas-abrasive mixture can be used as a working material, while abrasive blasting is increasingly used, a larger number of materials are included in the working material.

Known sandblasting tool with a local water curtain [RF Patent No. 2381889, publ. 20.02.2010, bul. No. 5], containing a housing, a cylindrical element for supplying a pneumatic abrasive mixture, an outlet nozzle in the form of a Laval nozzle with means of axial movement, a pipe, means of mutual movement and fixation, and a swirler to form a local water curtain around the abrasive jet. The outlet nozzle is installed with a gap coaxially to the cylindrical element at its other end to form an annular groove in the housing. The branch pipe is in communication with the cavity of the annular groove. The swirler is designed to form a local water curtain around the abrasive jet and is installed at the end of the cylindrical element. The outlet section of the swirler is open to the confuser of the Laval nozzle, and the inlet section is open to the said annular groove. The branch pipe is connected to a water source.

In this design, three types of material are used to influence the treated surfaces - gas, abrasive and water. However, water is used only to create a curtain in order to reduce the dustiness of the treatment site and does not affect the parameters of the technological process.

The closest technical solution to the claimed utility model, taken as a prototype, is a thermo-steam-abrasive-jet tool for cleaning surfaces [RF Patent No. 2486046, publ. 27.06.2013, bul. No. 18]. The device contains a mixing chamber, in the body of which there are an ejection channel for supplying abrasive materials and an ejection channel for supplying a heated liquid. A Laval nozzle is installed inside the mixing chamber to form a high-speed jet of gas flow. The ejection channel for supplying the heated liquid is configured to vaporize said liquid at its outlet. The outlet of the ejection channel for supplying the heated liquid and the cut of the end part of the Laval nozzle are arranged to ensure uniform mixing of abrasive particles with liquid vapors in a thermomechanical flow consisting of liquid vapors and abrasive particles in a gas stream.

The disadvantages of such a tool are the inability to adjust the amount of steam supplied to the mixture, the impossibility of providing high steam temperatures, since it is formed directly due to the evaporation of the liquid and cannot be additionally heated, which sharply reduces its effect on the treated surface. And these two parameters play a very important role in the processing of various surfaces.

Disclosure of a utility model

The technical result of the utility model is to increase the efficiency of abrasive blasting with additional use of steam.

The technical result is achieved due to the fact that the nozzle of the apparatus for steam-abrasive-jet processing is proposed. The nozzle contains a mixing chamber, in the body of which an ejection channel is installed for supplying an abrasive-gas mixture. The channel is made in the form of a Laval nozzle. A channel for supplying superheated steam is also installed in the body. The axes of the channels intersect at an acute angle inside the mixing chamber. The fitting of the steam supply channel is made with the possibility of axial movement and fixation. The cut of the nozzle of the channel for supplying steam can be set both at the level and closer to or further from the cut of the channel for supplying the abrasive-gas mixture. The axes of the channels for supplying the mixture and steam intersect at the cut-off level of the nozzle outlet. The angle of intersection of the axes of the channels for supplying the mixture and steam is from 10 to 45 degrees.

List of drawings

The figure shows a diagram of the nozzle of the apparatus for steam-abrasive-blasting.

Implementation of the utility model

The nozzle of the apparatus for steam-abrasive-jet processing contains a cylindrical body 1, in which a channel for supplying an abrasive-gas mixture 2 is made coaxially with it, having the shape of a Laval nozzle. In the housing 1 there is a fitting 3 for steam supply. The nozzle is fixed in the body by means of a threaded connection, which allows you to move the cut of the nozzle of the channel for steam supply along the axis of the nozzle. To fix the union in a certain position, a lock nut 4 is used.

The nozzle works as follows. When you turn on the supply of the working mixture and the processing of the test area of the surface to be treated, by rotating the nozzle 3, the optimal position of the nozzle is selected, at which the best result of cleaning the test area of the surface is achieved. This position is fixed with a lock nut for the duration of the operation. Different types of products to be cleaned require a different ratio in the flow of working mixture and steam acting on the surface. The effectiveness of the use of the nozzle is confirmed by comparative tests for cleaning the surface of polished marble. As a comparison, a Vecfort soft soda blasting machine was used, in which water is used to eliminate the dusting of the abrasive. In the installation with the inventive nozzle, water was consumed only for the formation of steam directly involved in the treatment process. The active influence on the contaminated surface of the steam promotes the softening of organic particles and the partial dissolution of mineral particles in the contamination layer, which intensifies the process of its removal. At the same time, the steam, condensing on the treated surface, actively prevents dusting, which does not require an additional water curtain. The additional action of steam, therefore, reduces the consumption of working material, which reduces the damage to the surfaces to be cleaned, and this is especially important when cleaning ancient buildings and antiques. The range of intersection angles of the axes of the channels for supplying the abrasive-gas mixture and supplying steam was determined experimentally. When the angle is less than 10 ° and more than 45 °, the sensitivity of the change in the ratio of the components entering through the two channels of the packing decreases significantly. Therefore, the technology in comparative tests was named based on the terms accepted abroad as steam-sodo-blasting. The results of comparative tests are shown in the table. The first line shows the indices of soft soda blasting, the second shows the values of the indices of steam abrasive blasting with the described nozzle.

The use of the nozzle of the apparatus for steam-abrasive-jet processing will significantly increase the efficiency of abrasive-jet processing.

Claims (2)

1. A nozzle of an apparatus for steam-abrasive-jet treatment, containing a mixing chamber, in the body of which an ejection channel for supplying an abrasive-gas mixture, made in the form of a Laval nozzle, and an ejection channel for supplying superheated steam are installed, characterized in that the axes of said channels intersect at an acute angle inside the mixing chamber, and the steam supply channel fitting is made with the possibility of axial movement and fixation to ensure that the cutoff of the steam supply channel fitting is installed at a level closer to or further from the channel cutoff for supplying the abrasive-gas mixture in the direction of supplying the steam mixture with an abrasive gas mixture. 2. Nozzle of the apparatus for steam-abrasive-blasting according to claim 1, characterized in that the angle of intersection of the axes of the channels for supplying the mixture and steam is from 10 ° to 45 °.

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