Tectonic coal block type briquette coal triaxial sample preparation device and method with controllable apparent density

Abstract

Disclosed is a tectonic coal block type briquette coal triaxial sample preparation device with controllable apparent. The sample preparation device comprises a concrete fixed groove with an opening inthe top; a molding box is arranged at the upper part in the concrete fixed groove; an upper positioning and plugging system is arranged between the top of the molding box and a fixed plate, and a cutting sampling system is arranged on the upper positioning and plugging system; a lower pressurizing system is arranged between the bottom of the molding box and the bottom of the concrete fixed groove; a left pressurizing system is arranged between the left side part of the molding box and the left side wall of the concrete fixed groove; and a front pressurizing system is arranged between the front side part of the molding box and the front side wall of the concrete fixed groove. The invention further discloses a sample preparation method of the tectonic coal block type briquette coal triaxialsample preparation device with controllable apparent. The triaxial pressing process provided by the invention better conforms to the stress state of the in-situ layer, and the stress distribution ofthe sample in the briquette coal pressing process is more uniform; the coal sample apparent density change can be monitored in the briquette coal pressing process, so that the pressing degree of different coal samples can be controlled; and damage of coal samples in the de-moulding process can be reduced to the maximum extent.

Description

technical field [0001] The invention belongs to the technical field of briquette pressing, and in particular relates to a three-axis sample preparation device and method for structural coal block-shaped briquettes with controllable apparent density. Background technique [0002] Structural coal with different degrees of deformation is widely developed in my country's coal reservoirs. The macroscopic characteristics of structural coal with strong deformation are mostly powdery or small pieces, which can be broken by hand. Therefore, structural coal powder is usually pressed into block or cylindrical shape. coal to facilitate related research work. [0003] The more commonly used compression method at the current stage is the uniaxial compression method. The uniaxial pressing method refers to using a press to press the coal powder in the mold from one direction until it is formed, but this kind of pressing method can only control the stress applied in a single direction, which...

AI Technical Summary

Problems solved by technology

The uniaxial pressing method refers to using a press to press the coal powder in the mold from one direction until it is formed, but this kind of pressing method can only control the stress applied in a single direction, which may easily cause uneven stress distribution and the solidity of the sample. The degree of knot cannot be reflected directly

Due to the difference in the degree of deformation and metamorphism of structural coal, the coal body structure is quite different, and the pressing requirements of different structural coals are different. However, the conventional sample pressing method only controls the pressing process by adjusting the stress, and generally presses to the consolidated state. For the target, the pressing process lacking apparent density control is prone to overpressure or underpressure, which will cause large errors in subsequent experiments, and even directly cause sample pressing failure; The demoulding process mainly adopts the method of direct extrusion. This demoulding process will form a large stress difference at both ends of the sample, which is easy to damage the uniformity of the sample, and the coal sample will be subjected to the friction of the side wall when it is extruded. The force will cause the side of the coal body to be dragged, further causing damage to the coal body sample; finally, the samples pressed by the conventional sample pressing method are mainly cylindrical samples with a small size. The method is not applicable, and the pressing success rate is low

[0004] Due to the many problems mentioned above in the uniaxial compression method, the existing research on tectonic coal is limited to the relevant directions suitable for smaller-sized samples, which seriously restricts the research on large-sized tectonic coal. pressing device

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