Large-caliber sampling device and system for columnar sediments in lake

Abstract

The invention provides a large-caliber sampling device and system for columnar sediments in a lake. The sampling device comprises a sampling tube, wherein a sampling head is connected with the upper end of the sampling tube and comprises an upper cover and an extension rod; the upper cover is detachably connected with the upper end of the sampling tube, and is provided with at least one water outlet; the extension rod is longitudinally arranged at the middle part of the upper cover, and is provided with a weight balancer; a guide hole provided with a downward opening is formed in the middle part of the sampling head; a first piston is arranged inside the sampling tube; a through hole is formed in the middle part of the first piston, and a valve is arranged at the upper part of the first piston; a guide rod is arranged at the upper part of the valve; the guide rod can stretch into the guide hole and can freely move up and down. The system comprises a sampling platform, a jacking device for sediments, a sampler and a sample separating frame. The sampling device provided by the invention can conveniently discharge water inside the sampling tube, and seal the first piston when the sampling tube is lifted upward to prevent sediments inside the sampling tube from slipping off, so that the sampling tube can be conveniently machined into a large-caliber sampling tube.

Description

technical field [0001] The invention relates to a collection tool for sediment columnar samples of lakes (including reservoirs). The advantages are that the collected sediment column samples have a large amount (diameter can be greater than 15cm), the surface sediment is not disturbed during the sampling process, and the collected surface sediment water and soil The interface is clear, the sediment sequence is kept intact, and the sedimentary columnar samples up to 150cm can be collected. With the sample separation rack, the equidistant cutting of the collected sedimentary columnar samples can be accurately performed. It belongs to the mechanical field. [0002] Background technique [0003] Lake sediments continuously record the information of regional and even global environmental changes, and are an important carrier for reconstructing the environmental evolution process of historical lakes and watersheds. They have played an increasingly important role in past global ch...

AI Technical Summary

Problems solved by technology

For example, the study of large fossils of plants, which are important sedimentary paleoecological indicators, normally requires at least 100 ml of sediment for each sample, while ordinary gravity samplers (5.8 cm or 8.4 cm in inner diameter) can only divide samples at intervals of 1 cm. Provides a sample volume of about 26ml and 56ml, so it is often necessary to mix samples from several adjacent depths for analysis, which cannot meet the requirements of high-resolution analysis of indicators

[0006] Secondly, although multiple sedimentary columns can be continuously collected to meet the demand for sample volume, due to various uncontrollable factors in the on-site sampling of the water surface, it is necessary to obtain multiple sedimentary columns with the same length, consistent horizons, and comparative It is difficult to drill a good hole; and when the sediment is manually cut, there will be some differences in the thickness of different pillars, which leads to the problem of inconsistency in the comprehensive comparative analysis of sedimentary pillars and multiple indicators. The scientific explanation of the mechanism directly affecting the environmental change

[0007] Thirdly, in order to increase the sample volume of the sedimentation column, methods such as increasing the caliber of the sampling tube and prolonging the sampling depth cannot be simply carried out on the existing sampler, because there are some technical difficulties as follows: 1) The sample volume of the sedimentation column is large, and the sampler (including heavy Hammer) is heavy, how to lift it from the bottom mud? 2) As the caliber of the sampler becomes larger, the overall weight of the sediment also becomes larger. How to ensure that the sediment column does not fall off when the sediment column is lifted to the water surface? 3) When dividing the sample, the volume and weight of the sedimentation column are relatively large, and it is impossible to divide the sediment like the traditional small-diameter sampler (usually using a hand-held type and using a piston to push the sediment out for cutting). How to separate the sedimentation column Isometric cut

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