JPS5834189B2 - Internal cleaning method during centrifugal mortar lining construction - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inner surface cleaning method for removing lentance generated on the lining surface when mortar lining is applied to the inner surface of an iron pipe using a centrifugal force method.

When a mortar lining is formed on the inner surface of a pipe using the centrifugal force method,
A thin layer of light component lentance occurs on the inner surface.

When this component dries after cement curing, it becomes a soft free component and greatly reduces the adhesion of the subsequent internal coating.

Conventionally, in order to remove lentance, the pipe is tilted immediately after lining is installed, and water is run from the top end while rotating to clean the pipe.Furthermore, lentance is removed by brushing as a pre-process for interior painting.

However, since the lentance layer adheres to the cement paste layer below with a certain degree of adhesion, it is difficult to separate it from the cement paste layer, and the above-mentioned peeling force from the water flow is not sufficient to remove the lentance. .

Even if residual lentance is removed by brushing in a post-process, the burden will be heavy.

Therefore, it is desirable to remove as much lentance as possible immediately after lining construction.

In recent years, with the diversification of needs, the usage conditions for pipes have become increasingly strict, and it is therefore desirable to completely remove the mortar surface, which is a determining factor in the internal performance of pipes.

The present invention proposes an inner surface cleaning method that can reliably remove lentils, and one embodiment thereof will be described below with reference to the drawings.

Reference numeral 1 denotes a cast iron tube, which is placed at an angle on a tube rotation drive device 2 consisting of a plurality of rollers.

The pipe 1 has just had a mortar lining 3 applied to its inner surface using the centrifugal force method, and the mortar lining 3 consists of a mortar layer 4 consisting of a component with a high gravel content due to the difference in specific gravity, a cement paste layer 5, and a letance layer. 6.

A spray lance 7 has a spray nozzle 8 at its tip for spraying pressurized water.

The spray nozzle 8 may be of any type, such as having a circular, annular or fan-shaped spray range.

In this way, the pipe 1 immediately after lining is placed on the pipe rotation drive device 2 with a slight slope, and while the pipe 1 is being rotated, jet water is sprayed from the spray nozzle 8 onto the mortar lining. 3 to remove the lentance layer 6.

The spray nozzle 8 is advanced from the upper end of the tube 1 to the lower end.

In this way, since the lenance layer 6 is removed by applying a certain amount of force using pressurized water, the lenance layer 6 adhering to the cement paste layer 5 can be removed at a much higher removal rate than conventional washing with water. can.

Moreover, since the pressurized water is in a spray state, the latitude layer 6 can be removed without damaging the cement paste layer 5, and the inner surface of the mortar lining 3 after removal can be made smooth.

Therefore, the burden of brushing later is reduced and efficiency is improved.

Further, it is possible to reliably remove lentance, and the performance of the coating film applied to the inner surface of the mortar lining 3 can be improved.

The discharge pressure and flow rate of pressurized water sprayed from the spray nozzle 8,
The spray speed, fountain diameter, and advancing speed of the spray nozzle 8 affect the removal rate of the lentance layer 6 and the smoothness of the inner surface after removal, and therefore need to be set appropriately.

According to the experimental results, for the spray nozzle 8 that sprays in a linear range as shown in FIGS. That is, F/L is 2. lX10-
3≦Q′≦3. It has been found that a range of 1X1O-31/-m.times. is appropriate.

F is the jetting flow rate from the spray nozzle 8, and L is the jetting length range.

In the case of the spray nozzle 8 that sprays in a fan shape as shown in FIG. 3A, L indicates the linear length, and in the case of the spray nozzle 8 that sprays in an annular shape as shown in FIG. 3B, L indicates the circumferential length.

The injection angle θ is 600 in both cases.

Generally, the spray particle size, that is, the fountain diameter, is preferably smaller.

The injection speed, that is, the flow speed in the orifice of the spray nozzle 8 is 10 crn/sec to 35 crn/sec.
range is desirable.

The following table shows the experimental results. Cases where very good results were obtained for both the removal rate and the inner surface condition after removal are marked with an ○, cases where the results are reasonably good are marked with a Δ, and cases with poor results are marked with an X. Indicated by

The same table shows the fan-shaped spray nozzle 8 in Figure 3A and the fan-shaped spray nozzle 8 in Figure 3B.
This is a comparison of various unit orifice diameters and discharge pressures for the annular spray nozzle 8 shown in FIG.

In this case, the distance l from the spray nozzle 8 is 30c.
The traveling speed of the IrL1 spray nozzle 8 is 10 to 30 m,
,'sec.

From this, the spray flow rate is 1.2 to 1.71j/mrn
was found to be optimal.

As explained above, according to the method of the present invention, lentance is removed by spraying pressurized water, so lentance can be removed with high efficiency immediately after mortar lining is formed, and the inner surface of the lining after removal can be removed. Can be made smooth.

[Brief explanation of the drawing]

The drawings show an embodiment of the method of the present invention; FIG. 1 is a sectional view of the tube installed in a tube rotation drive device, FIG. 2 is a cross-sectional view of the tube, and FIGS. 3A and 3B are views of the spray nozzle. It is an explanatory view showing an example of an injection range. 1...Pipe, 2...Pipe rotation drive device, 3
... Mortar lining, 4 ... Mortar layer, 5 ... Cement paste layer, 6 ...
...Lightance layer, 8...Spray nozzle.

Claims (1)

[Claims] 1 Immediately after forming the mortar lining on the inner surface of the tube using the centrifugal force method, while the tube is being rotated, pressurized water is sprayed onto the lining surface from a spray nozzle that moves in the axial direction within the tube to reduce the latitude of the lining surface. A method for cleaning the inner surface during centrifugal force lathe turning, which is characterized by removing a layer.