SU859537A1 - Apparatus for retaining alluviums - Google Patents

Description

one

FIELD OF THE INVENTION The invention relates to hydraulic engineering, in particular, to devices for controlling the closure of the flush locks of the irrigation tanks.

A device for flushing irrigation sedimentation tanks is known, which includes a sediment level sensor, made with a vertical pipe, installed in a well, which is connected by means of pipelines with the settling chamber to the downstream of the washing gateway 1.

The disadvantages of such a device are manufacturing complexity and low speed.

It is also known a device for retaining sediments (a "gravel detector"), which includes an inlet part and a discharge pipe, interconnected by a funnel, extending toward the discharge pipe 2.

The disadvantages of such a device are a small range of operation, i.e. the device ensures the operation of the entire system only at certain (limited) fractions of the incoming sediments, moreover, for the “gravel detector”, a low speed is characteristic, namely

when sediments enter it, the time for stopping water supply to the system is significant due to the fact that sediment of small fractions is in a state of, i.e. their weight is balanced by the pressure of the incoming water, and as a result, the sand does not condense and passes water for a long time until the opening hardens with smaller sediments, as well as large capital and operating costs for both construction and

fQ for inspection, repair, cleaning of the device itself; the need for the device of additional funds in case of failure of the Gravel Detector.

The purpose of the invention is to expand the range of operation and increase speed and

15 reliability.

Claims (2)

This goal is achieved by the fact that the funnel is made in the form of a truncated quadrangular pyramid with an inlet in the form of a quadrangular prism, the size of the entrance section of which is equal to the size of the smaller base of the quadrilateral pyramid. FIG. 1 shows the proposed device, an axial section; in fig. 2 - the same, top view; in fig. 3 shows section A-A in FIG. 2; in fig. 4 shows a section BB in FIG. 2; FIG. 5 and 6 - “detector of gravity and flow velocity diagrams in the longitudinal direction in it, respectively; in fig. 7 and 8 of the proposed device and diagrams of flow rates in the longitudinal direction therein, respectively; in fig. 9 and 10 - “detector of gravity and velocity diagrams in section BB, respectively; in fig. 11 and 12, the proposed device and velocity diagrams in the section of GG, respectively. The device for retaining sediment consists of the inlet part 1, the funnel 2 and the discharge of the pipeline 3. The device operates as follows. When the water in the settling chamber is clean, it passes through the sediment containment device. When sediment flows into the sedimentation tank, their sedimentation and precipitation begins. As the sedimentation tank is sedimented, sediment will begin to reach the inlet part 1 of the sediment containment device, made in the form of a quadrangular prism. The funnel 2 of the sediment containment device is designed as a truncated quadrangular pyramid. This constructive embodiment allows to reduce the vertical flow rate due to a sharp increase in the cross-sectional area during the transition from the inlet part 1 to the funnel 2 and, as a result, sedimentation of fine fractions occurs. The mechanism of operation of the device can be explained as follows: particles of sediment together with the stream enter the inlet part 1 and as they rise upward through the funnel 2 decrease their speed in proportion to the increase in the cross-sectional area of the funnel 2 and fall to the side faces. The main part of the sediments is deposited at the interface of the lateral faces of the funnel 2, where the velocity quenching zone is formed due to the larger area in the longitudinal section. In this case, the flow, moving up the funnel (in the pyramid), has different velocities in cross section. To more clearly show the work of the gravel detector and the proposed device, we present diagrams of flow velocities in them both in the longitudinal (Fig. 5-8) and in cross section (Fig. 9 - 12). As can be seen from the plot (Figs. 5 and 6), the flow rate in the longitudinal direction in the expanded part of the gravity detector decreases, , transported further into the system. In the proposed device (FIGS. 7 and 8) there is no abrupt change in velocity between the inlet part 1 and the beginning of the funnel 2. Consider the plot of flow velocities in the cross sections of the funnel for both the gravity detector and the device. As can be seen from the velocity plot in the gravity detector (Figures 9 and 10) in cross section BB, the maximum and minimum velocities are the same, which prevents sediment of small fractions from settling in the funnel and they will be transported into the system. Otherwise, the diagram of the velocities in the cross section of the G – H of the proposed device irons (Figs. 11 and 12). A part of the flow slows down its speed at the edges of the pyramid, while the part that has high speeds goes further and forms secondary speeds, creating the effect of self-extinguishing. This phenomenon is most pronounced at the interface of the lateral faces of the pyramid, with the formation of a flow velocity quenching zone, which is not observed in the "gravity detector cone" (Fig. 9 and 10). The effect of quenching the flow rate can be explained as follows: the flow of water moving upwards across the cross section has unequal speeds (Figs. 11 and 12), which causes increased internal friction and stalling of water masses with increased speeds in the region with reduced speeds. , and due to this, the speed quenching and sedimentation sedimentation occurs. The sediments deposited on the edges of the pyramid form prisms of sediment. As they form, they increase in volume and are interconnected. At the same time, under their own weight, they begin to crawl down the edge of the pyramid and close the opening, as a result of which the flow of water into the system stops. The advantage of the proposed device is its simplicity of implementation, wide range of operation and increased speed, which allows reducing non-productive discharge of water into the system. Claims of Invention A device for detaining sediment, including an inlet part and a branch pipe, interconnected by a funnel, extending to the side of an outlet pipeline, characterized in that, in order to expand the range of operation and increase speed and reliability, the funnel is made in the form of a truncated quad the pyramid with the entrance part in the form of a quadrangular prism, the size of the entrance section of which is equal to the size of the smaller base of the quadrangular pyramid. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 279442, cl. E 02 B 8/02, 1970. 2. Bondar F. I. and others. Special water intake facilities. Gosstroyizdat, 1963, p. 103-105 (prototype). b1 V uil Ll. B-s J Fig.Z Fy