Testing device capable of observing cohesive sediment flocculation and settling under different velocity gradients

Abstract

The invention discloses a testing device capable of observing cohesive sediment flocculation and settling under different velocity gradients. The upper part of a vertical hollow settling column in the upper and lower ends of which openings are formed is communicated with a water collection tank; the upper end of a floc separation chamber is connected with the lower end of the hollow settling column; a floc collection opening used for collecting one part of floc in the hollow settling column into the floc separation chamber is formed in the upper end of the floc separation chamber; a sediment collection chamber is formed below the floc separation chamber and is used for collecting other floc which is not introduced into the floc separation chamber; and an image acquisition device is mounted beside the floc separation chamber. Due to the design of the hollow settling column, the sediment floc is in a settling state; due to the designed floc separation chamber, one part of detected floc is separated from the other floc, and the condition that too much floc is mutually interfered is avoided, so that the measurement accuracy is obviously improved and due to the image acquisition device, the floc image is acquired so as to analyze the particle size and settling rate of the floc formed after cohesive sediment flocculation and settling.

Description

technical field [0001] The invention relates to a test device for observing cohesive sediment flocculation and settlement in water conservancy projects, in particular to a test device for observing cohesive sediment flocculation and settlement under different velocity gradients. Background technique [0002] The flocculation of fine-grained sediment in the estuary and coastal waters is the main cause of sedimentation in estuaries and coasts; and the sedimentation and accumulation of sediment usually raises the bed surface and affects navigation. , causing environmental hazards. [0003] In cohesive sediment flocculation process, floc particle size is an important research parameter. According to previous studies, the fluid shear force is an important factor affecting the flocculation and settlement of cohesive sediment; under a certain fluid shear force, when the aggregation and fragmentation of the flocs are in balance, the particle size distribution of the flocs tends to ...

AI Technical Summary

Problems solved by technology

In the past, the devices used to study sediment flocculation and settlement include flocculation agitators, settling drums, etc., but they all have different degrees of defects. For example, flocculation agitators can only generate high-strength shear forces, and cannot simulate the shear conditions of low-velocity rivers. , and the height of the flocculation agitator is small, the sediment has settled without sufficient flocculation, and the particle size of the floc under equilibrium conditions cannot be observed; most of the settling cylinders used by most scholars have the following defects: 1. There is no vibrating grid, and they cannot Generate uniform and isotropic turbulence; 2. The height of the settling cylinder is small, and the equilibrium condition cannot be reached; 3. The flocs are not separated. When combined with the camera equipment experiment, the mutual interference between the sediment is large, and the ideal floc image cannot be obtained.

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