Preparation method of modified evaporation wall for supercritical water oxidation reactor

Abstract

The invention provides a preparation method of an evaporation wall for a supercritical water oxidation reactor. The preparation method comprises the following steps: 1, substituting the water film flowing speed of the inner surface of the evaporation wall of the reactor into a formula I and a formula II, and calculating corresponding adhesive force gamma<lv>w(theta<adv>-theta<rec>); 2, cleaning ametal porous plate and using the cleaned metal porous plate as an evaporation wall matrix; 3, putting the evaporation wall matrix into acid for acid etching, and adjusting the reaction time and the reaction temperature of an acid etching reaction according to the theoretical value of the adhesive force obtained in the step 1; 4, washing the evaporation wall matrix having undergone the acid etchingreaction in the step 3 with deionized water, and carrying out drying in a drying oven; 5, sintering the evaporation wall matrix cleaned and dried in the step 4 in a high-temperature sintering furnaceto obtain a modified evaporation wall with micro-nano rough morphology on the surface, wherein the formula I is that ma = F = mg - gamma<lv>w(theta<adv>-theta<rec>), and the formula II is as described in the specification. According to the method, the integrity and stability of a water film on the inner surface of the evaporation wall can be maintained, so the evaporation wall type reactor is more corrosion-resistant, and the service life of the evaporation wall type reactor is prolonged.

Description

technical field [0001] The invention relates to the technical field of supercritical water oxidation evaporation wall reactors, in particular to a preparation method of a modified evaporation wall for supercritical water oxidation reactors. Background technique [0002] Supercritical water oxidation (SCWO) technology is a high-efficiency, thorough treatment and deep oxidation of organic matter without secondary pollution proposed by Modell et al. in the mid-1980s. Under high temperature and high pressure (usually reaction temperature 400°C-600°C, reaction pressure 25MPa-40MPa), supercritical water is used as the medium, air, oxygen and other oxidants deeply oxidize and decompose organic matter, and are widely used in chemical industry, metallurgy, printing and dyeing, Industries such as paper making, medicine, petroleum and food. It has great application prospects in dealing with military poisonous materials such as chemical weapons, rocket solid fuel materials, explosive m...

AI Technical Summary

Problems solved by technology

[0004] The upper part of the supercritical water oxidation evaporation wall reactor is the main part of the oxidation reaction. It is in the intense chemical reaction area and the supercritical environment of high temperature and high pressure. The convective diffusion and mixing between the main fluid and the water film are extremely strong, making the upper part of the evaporation wall The continuity of the water film is destroyed; and the water film flows down instantly under the action of its own weight, and the integrity of the water film on the upper part of the evaporation wall is difficult to maintain, so that the upper part of the evaporation wall that is not protected by the water film is easily burned or corroded

[0005] In view of the above problems, in the existing processing methods, the patent application of Ma Chunyuan et al. (publication number CN101164912A) discloses a structure of "annular water inlet and water retaining ring", but the water film in each local partition is still uneven; Wang The patent application of Bing et al. (publication number CN 107385261A) prepared a porous evaporation wall with an average pore size of 2-10 μm and a porosity of 10%-35%, which is conducive to the formation of a complete water film, but cannot slow down the instantaneous flow of the water film. No significant improvement in maintaining water film integrity

The patent application of Xu Donghai et al. (publication number CN 109133317A) realizes the adjustment of the thickness of the water film by adjusting the evaporation intensity, the concentration of the organic raw material, the preheating temperature of the organic raw material, the inlet temperature of the evaporating water, and the water flow ratio of the evaporating wall of each branch. However, this method greatly increases the complexity and difficulty of reactor operation, and requires high-precision and high-sensitivity detection equipment that can withstand harsh conditions in the reactor, which is difficult to apply to industrial applications

In short, the existing methods for improving the evaporation wall are limited to water-retaining parts or adjusting process parameters, but the above-mentioned methods are not only very complicated in equipment and operation process, but also unable to change the incomplete and unstable state of the local water film, which is difficult to apply to industrial applications

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