Automatic sample feeding mechanism for light hydrocarbon

Abstract

The invention relates to an automatic sample feeding mechanism for light hydrocarbon, and the mechanism is composed of a chassis, an injection assembly, a sampling assembly, a transmission positioning assembly and a four-way switching assembly, wherein a framework shape is formed by a guide column of the injection assembly, a cylinder body of an air cylinder A, and front and back fixing blocks; middle grooves of the front and back fixing blocks are used for clamping a syringe; a profiled groove is machined in the middle of a protruding part of a guide slide block and is used for clamping a push rod end part of the syringe; the guide slide block and a piston rod of the air cylinder A are in threaded connection; an A connector of a four-way valve is communicated with a syringe of a sampling needle through an air pipe; a B connector of the four-way valve is connected with a gasifying chamber; and a C connector of the four-way valve is connected with the syringe; a control system is used for pumping sample gas into a quantitative pipe according to a procedure and the sample gas is brought into the gasifying chamber through carrier gas; the four-way valve directly uses the syringe to pump the sample gas; and then the sample gas is switched to the gasifying chamber through the four-way valve to be subjected to sample injection. According to the automatic sample feeding mechanism, the sample feeding speed and precision are guaranteed, the structure is simple, the installation is convenient, and the problem of breaking of the needle cannot happen; and a sampling pump is not needed and the automatic sample feeding mechanism is applicable to a sample bottle with capability of tens to hundreds of millimeters; and the sampling amount is smaller and does not exceed 1 millimeter, therefore, the automatic sample feeding mechanism of the light hydrocarbon is good for multiple times of analysis of the same sample, and has good quick flowing-out effect and high separation degree.

Description

technical field [0001] The invention relates to the preparation and sampling technology of light hydrocarbon analysis samples in the petroleum mud logging industry, in particular to an automatic light hydrocarbon sampling mechanism, which is used for the preparation of light hydrocarbon analysis samples. Background technique [0002] Light hydrocarbon analysis is an emerging analysis technology in the oil logging industry, which requires the analysis of nC1-nC9 alkanes and aromatics within 30 minutes. It has special requirements for sample preparation and sampling. 1 Sampling requirements are representative. A large amount of sampling is required, and the sample bottle ranges from tens of milliliters to hundreds of milliliters. None of the robotic autosamplers currently on the market can meet this requirement. [0003] 2 For headspace sampling, the resolution R of methane and ethane is required to be not less than 1. The six-way valve-type headspace sampler curr...

AI Technical Summary

Problems solved by technology

Due to the large dead volume in front of the column, the six-way valve-type headspace sampler on the market is prone to tailing in the range of nC1-nC5, which affects the resolution.

At the same time, the demand for headspace is extracted by the sampling pump, which is not conducive to repeated analysis

Images