SU95612A1 - The method of cleaning and polishing the inner surface of pipes - Google Patents

Description

The subject of the invention is a method for cleaning and finishing the inner surface of straight and bent pipes and an apparatus for carrying out this method.

Methods for cleaning and finishing the inner surface of pipes with compressed air spray sand are generally known. In the known apparatus, particles of sand, moving through the pipe at a high speed and trying to maintain a straight linear motion, hit the bent wall of the inner part of the bent pipe and process it while the convex wall remains untreated. The increase in processing time causes only a further decrease in the thickness of the concave wall of the pipe.

In the method described below, in contrast to the known methods, cleaning is performed by squeezing dry sand or abrasive blasting through a closed loop at a low speed through compressed air using compressed air, and due to the sand density, it is in contact with both the concave and convex walls of the pipeline. At the end of a predetermined cycle, processing stops automatically.

The proposed method ensures uniform cleaning or finishing of both the concave and convex surfaces of the curved pipeline, automating the process and eliminating noticeable sand losses.

FIG. 1 shows a diagram of the apparatus in the preparatory cycle of its cycle; on phpg. 2 - the same, in the working cycle; in fig. 3 shows a machine for turning off the apparatus in a section; in fig. 4 - section along. LL PA FIG. 3

The main units of the apparatus are the upper / lower and the lower 2 sand bins, plume specks 3, spool regulator 4, the starting crane 5, the bleed valve 6 and the automat 7 for turning off the apparatus.

The pipe 8 to be machined is installed using replaceable re-nos. 95612-2 -

between the ends of the hoses 9 and 10. Then open the valve 5, and the compressed air from the air network enters the controller 4.

During the preparatory cycle (see Fig. 1), the spool // of the regulator is moved by the spring 12 to the lower position. Air through the tube 13, the upper recess of the spool and the tube 14 enters the left cylinder cavity of the piston valve 3. The piston 15 is moved to the far right position and opens air access from the tube 16 through the longitudinal holes in the piston rod into the hopper. At this moment, the hole in the tube 17 is closed with a rubber valve 18 attached to the stem,

Opening the valve 19, the air enters the bunker 2, one third filled with dry sand or abrasive powder, and the pressure in this bunker rises to 4 MPa.

From this moment the working cycle of the apparatus begins (see Fig. 2). Under the pressure of air in the bunker 2, the diaphragm 20 mixes, the spool 11 upwards, and the air from the tube 13 begins to pass through the lower recess of the spool and the tube 21 into the right cavity of the cylinder of the piston crane, with the piston 15 mixed: to the extreme left.

The access of air from the tube 16 to the bunker / is stopped, and the valve 18 is opened, the compressed air from the bin comes into the atmosphere, and the pressure in the bunker drops. Due to the pressure difference in the bins 1 and 2, the shutter J9 is closed and the sand from the bunker 2 is burned through the hose 10, the machined pipe 8 and the hose 9 into the bunker /. In the bunker, the sand settles to the bottom, and the air with suspended fine dust escapes through valve 18 to the atmosphere.

The sand is expelled from the hopper 2, the air expands and the pressure in the hopper drops to 2 MPa. The spring 12 overcomes the resistance of the diagram 20 and mixes the spool 11 to the lower position: From this moment the next preparatory cycle begins, which differs from the previous one in that the air coming from the bunker 2 into the bunker / pre-forces all sand from the upper bunker.

The device is turned off by closing the valve 5 (see Fig. 1) and opening the valve 6. In addition, to simplify servicing, the device can be turned off automatically after a predetermined number of processing cycles. The machine shutdown device has a cycle counter, built as follows: a spindle 22 is attached to the housing of the regulator 4 (see Fig. 3), the ratchet wheel 23 with the disk 24 is mounted. The counter shaft 25 is pressed against the spool 11 by a spring. A small dog 26. is fixed on top of the rod. Ea each cycle is a spool, and with it the rod makes one double move, and the dog turns the ratchet wheel 23 on one tooth. The teeth of the ratchet wheel are numbered, and at the initial moment of processing the ratchet wheel is turned counterclockwise so that the figure 0 is set in the frame of the counter.

With a new cycle, a number appears in the counter frame indicating the sequence number of the cycle.

An automatic stop is performed using a disk 24. If, for example, a pipe is required to be machined for ten cycles, the disk 24 is rotated relative to the ratchet wheel so that the disk arrow indicates the number 10 on the ratchet wheel. This position of the disk relative to the ratchet wheel is fixed by the button 27. At the eleventh cycle, the rod will no longer be able to lift up, as this is prevented by stops 28 and 29 that came into contact after the tenth cycle. The valve 11, locked together with the rod 25, stops controlling . a piston valve 3 (see Fig. 1), and the cleaning of the pipe is stopped.

Subject invention

Claims (5)

1. A method of cleaning and polishing the inner surface of pipes by advancing the abrasive material through the pipe cavity, in order to prevent the wall of the bent pipe from thinning, the abrasive material is advanced through the pipe cavity when the pipe is completely filled with abrasive and the abrasive speed is low. material. 2. Acceptance of the method according to claim 1, wherein the promotion of the abrasive material is carried out by means of compressed air. 3. A method according to claim 1, characterized in that sand or emery powder is used as an abrasive material. 4. The device for osun; 1-3, characterized in that it is made in the form of a two-to-abrasive and compressed air — hermetically sealed, entering one another, into bunkers connected to the passage of abrasive material by a pipeline, in the fracture of which the processable pipe is installed. 5. The apparatus according to claim 4, characterized in that it is equipped with a spool device, which automatically stops the supply of abrasive material after a predetermined number of cycles of its movement. fuz f 1B 15 18 3 P Rig 2 L, -j-, Kvv: fuz.S