Full-automatic COD (Chemical Oxygen Demand) analysis device

Abstract

The invention provides a full-automatic chemical oxygen demand analyzer, which comprises a condensation module, a heating module, a sample tube module, a linear module, a stepping motor, an outer box body, a color sensor, a light source and an automatic controller, and is characterized in that the condensation module comprises a condensation tube disc and a condensation water pipeline; the sample tube module comprises a sample tube turntable, two or more circles of sample tube insertion holes are formed in the surface of the sample tube turntable, and each sample tube insertion hole vertically corresponds to the insertion hole of the condenser tube disc; two or more circles of hole-shaped heating holes are formed in the surface of the heating module, a heating block is arranged in each heating hole, and each heating hole vertically corresponds to each sample tube insertion hole so as to accommodate a sample tube. Due to the fact that the sample tube or the sample cup is fixed in the vertical direction, the condensation module cools the condensation tube according to an instruction, the heating module conducts cold heating on the sample tube or the sample cup, the condensation tube and the heating module are separated from the sample tube through the linear module, and therefore simultaneous or differential high-throughput treatment of titrated samples is achieved.

Description

technical field [0001] The invention relates to a chemical oxygen demand (COD) measuring instrument in the field of environmental detection, in particular to a fully automatic chemical oxygen demand analyzer capable of realizing digestion and titration of high-throughput sample tubes, belonging to the field of analytical chemical detection. [0002] Background of the invention [0003] Chemical-Oxygen-Demand (Chemical-Oxygen-Demand), referred to as COD, refers to the mass concentration of oxygen corresponding to the strong oxidant potassium dichromate consumed by dissolved substances and suspended solids in water under certain conditions, expressed in mg / L meter. It is a comprehensive indicator of reducing substances in water. The COD in the water body is too high, indicating that the organic pollution is very serious, which will destroy the balance of the environment and biological communities, and cause the deterioration of the water body. Therefore, COD is an important ...

AI Technical Summary

Problems solved by technology

[0005] (1) This method strictly stipulates the test steps, such as the heating and digestion time, the acidity of the solution, the amount of oxidant and catalyst and other condition indicators. In the manual method of determination, different testers will inevitably produce test errors

[0006] (2) This method takes a long time, requires more reagents and utensils, is labor-intensive, and has low efficiency when measuring large quantities of samples

[0007] (3) The reagents encountered during the experiment are harmful to the human body, and the gas released due to high temperature digestion during the experiment also has a certain negative impact on the health of the testers

Although this invention is relatively simple, its disadvantage is that it is necessary to additionally set up an optical quantitative device similar to a buffer tank. If all the reaction solution is accommodated at one time, it will cause the digestion reaction to occur in advance and produce harmful gases and heat, which are difficult to control; Transferring the reaction solution will cause excessive residue in the reaction solution; the invention utilizes the change value of the current signal in the reaction cell to be monitored, which is completely different from the existing titration cell device, so it is not conducive to the existing COD detector. Improvement and application; In addition, the invention adopts potentiometric titration method for determination, which is substantially different from the detection standard of the present invention. Among them, high pressure and high temperature rapid digestion can only complete the absorption of a single sample, reagent addition, titration analysis, etc., and the experiment cannot be realized. High-volume multi-channel cycle fast analysis

However, the device does not fully comply with the operating specifications of the "HJ 828-2017 Standard", namely: (1) In order to simplify the device structure, the device can only add liquids to heavy metal reagents and light boiling point reagents through the condenser pipe liquid arm ; (2) Since the heating module is fixedly connected to the sample tray and driven to connect and separate from the condenser tube, the heating module cannot be directly separated from the sample tray after the heating time is over, and can only wait for the heat inside the heating module to gradually disappear. The sample tray is driven by the heating module and transferred to the titration position

Otherwise, if the heating module drives the sample carousel away from the condenser, it will cause the high-heat liquid in the digestion bottle to splash, which will affect the detection accuracy

Therefore, the design of the heating module fixedly connected to the sample tray prolongs the cooling time of the digestion solution, which is not conducive to the needs of rapid detection

[0015] In addition, there is usually only one digestion solution filling hole in the current screw-in liquid filling arm. If the liquid filling speed is too fast, it may rapidly impact the sample liquid and cause the liquid to splash. If it is too slow, or strictly follow the "HJ 828-2017 Water Quality Determination of Chemical Oxygen Demand The standard of "Dichromate Method" adopts manual sample addition, and the liquid addition speed will be too slow and it is difficult to ensure the liquid addition efficiency

At the same time, this kind of liquid filling arm is limited by the rotation axis, so it can only be suitable for sample filling of a single-circle sample tray

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