SU1666622A1 - Antifiltration screen - Google Patents

Abstract

The invention relates to the field of hydraulic engineering construction and can be used to create impervious screens of reservoirs. The purpose of the invention is to increase the reliability of the screen. The anti-filtration screen includes a smooth upper anti-filtration layer 1 and a lower anti-filtration layer 2 provided with ribs 3 which face the upper layer 1. The seams of the upper layer 1 are made in the direction perpendicular to the ribs 3 which are provided with drain holes. The distance between the holes is determined by the formula. 3 il.

Description

FIELD OF THE INVENTION The invention relates to hydraulic engineering, namely, devices that reduce the leakage of liquids into the ground.

The purpose of the invention is to increase the reliability of the screen.

Fig. 1 depicts a screen of the filter screen in a figvlan in Fig. 2, section A-A in Fig. 1, Fig. 3 shows a site of a filter screen with a welded seam.

The anti-filter eco-tank contains the upper smooth 1 m lower 2 anti-filtration layers with ribs 3 Between the anti-filtration layers 1 and 2 there is a gap 4 equal to the height of the rib 3 providing drainage of the liquid filtered through the seams 5 of the upper anti-filtration layer 1 The lower post-filtering layer 2 is laid on the base 6, made with a slope, providing a drain of the filtered liquid. To distribute the filtered liquid between the gaps A, in the fins 3, wastewater from versts 7 are made. g from each other at a distance opredet emom formula

I and LPT P hP 9 hl

QOTB

where QOTB fluid flow through the drain holes

Ootv, "absh V2gH - Vahp

V is the average velocity of the fluid in the gap between the ribs

V VR7

С - coefficient Chezy

C 87 / (1 + g VR).

R is the hydraulic radius

R ahp / (a 2hp)

L is the distance between the seams

A - consumption coefficient

Qty p - w / | 0ina holes in the edge

hp - rib height

H - the height of the layer of liquid above the screen,

Yu

a is the distance between the edges in the screen;

B.sh. - weld width;

I - slope;

V - coefficient of roughness.

The device works as follows.

The fluid filtered through the seams 5 of the upper impervious layer 1 enters the gap A. Since the base 6 is made with a slope directed toward the ribs 3, and the drain holes 7 are made in the ribs, the filtered liquid is evenly distributed over the entire area of the impervious screen and flows down the lower impervious layer 2 in the direction of the collection tray for this liquid. In this connection, the space between the fins 3 is not overflowed with water and the danger of their being eliminated is eliminated, which increases the operational reliability of the screen.

Claims (1)

DETAILED DESCRIPTION OF THE INVENTION An anti-filtration screen comprising upper and lower anti-filtration layers and a drainage device, the lower anti-filtration layer having ribs facing the upper layer, characterized in that, in order to increase reliability, the upper The impervious layer is made smooth with the location of the welds perpendicular to the fins of the lower impervious layer, and drain holes are made in the fins of the lower impervious layer, spaced from each other, determined by the formula I C hv hp QOTB where QOTB is the fluid flow rate through the drainage holes, determined by the dependence of QOTB and a. V2gH - Vahp; V is the average velocity of the fluid in the gap between the ribs, V With VRT; С - coefficient Chezy, C 87 / (1 + V / VR; R is the hydraulic radius, R ahp / (a - 2hp), / g is the flow coefficient; Lotr is the width of the hole in the rib; L is the distance between the welds; hp - rib height; H - the height of the layer of liquid above the screen; a is the distance between the edges in the screen; be sh - width of the weld; v - coefficient of roughness; i - slope. figure 1 6