Method for Removing Contaminants from Laboratory Magnetic Stirred Reactors (Part 3)

Previously, the editor briefly described several methods for removing long-term contaminants adhering to the inner walls of magnetic stirrer reactors used in laboratories. Now, continuing from the previous discussion, let’s talk about acid pickling, solvent-based removal, and ultrasonic cleaning. First, the acid pickling method—this method is primarily suitable for removing corrosive substances from the inner walls of magnetic stirrer reactors. In the acid pickling process, special attention must be paid to the fact that acid pickling can induce hydrogen embrittlement in materials such as austenitic stainless steel. Therefore, after acid pickling, it’s essential to immediately carry out a dehydrogenation treatment—baking at around 200 degrees Celsius for three hours. Additionally, the duration of acid pickling must be carefully controlled to prevent excessive corrosion of the reactor walls. After acid pickling, a neutralization treatment should be performed.

Method for Removing Contaminants from the Inner Wall of a Magnetic Stirred Reactor (Part 2)

For magnetically driven reactors that have been in long-term use, some stubborn residues tend to accumulate on the inner walls of the reactor vessel. These residues can impair reaction efficiency or lead to deviations in the reaction products, making their removal a significant headache for most operators. Below, experts from Weihai Magnetic Reactor will provide an online explanation to address this issue. The main removal methods include mechanical cleaning, alkaline and steam cleaning, acid pickling, solvent-based removal, detergent cleaning, and ultrasonic cleaning. This chapter focuses primarily on mechanical cleaning as well as alkaline and steam cleaning methods; for information on other methods, please refer to Method (II). I. Mechanical

Method for Removing Contaminants from Laboratory Reactors (Part 1)

It is crucial to select an appropriate method for cleaning the surface of the reactor vessel in laboratory reactors that are used over the long term. Common methods include mechanical cleaning, chemical cleaning, and solvent cleaning. However, no single method is universally effective. For example, solvent cleaning cannot remove corrosion products, steam degreasing cannot remove inorganic contaminants, nor can it effectively clean resin-based deposits. When choosing a cleaning method for the inner walls of laboratory reactors, the following points should be taken into account: First, it is essential to identify the type of contaminants present and select a suitable cleaning method accordingly. It is important to note that solvent-based cleaning—including solvent vapor degreasing, ultrasonic cleaning, and water-based detergents—is...

Design Method for Industrial Reactors

Before manufacturing, industrial reactors must have their volume, vessel dimensions, and cylinder wall thickness confirmed based on the requirements of the production process. Below, the designers from Weihai Self-Control Reactor Co., Ltd. will guide you through simple conversions related to these issues. First, Volume: The material balance should be calculated according to the reaction time and target production output. (1) Calculate the processing capacity of raw materials or the yield of products per unit time. Based on this processing capacity or yield and the rate equation, determine the reaction time. Then, use the reaction time to calculate the effective volume of the reactor. The total volume of the equipment is equal to the effective volume divided by a factor of 0.6 to 0.8. Second, Nominal Reaction Pressure: When the reaction process involves...

Application of High-Pressure Reactors in Supercritical Water-Related Experiments

Supercritical water is the state of water under conditions of high temperature (above 374°C) and high pressure (above 22.1 MPa). This supercritical water possesses many unique characteristics. For instance, it exhibits exceptionally strong oxidizing properties. When a reaction medium requiring treatment is placed into supercritical water and oxygen is then dissolved into it, its oxidizing power surpasses that of substances such as potassium permanganate. Moreover, many substances can be burned in supercritical water; additionally, supercritical water can dissolve a wide range of substances that are insoluble under conventional conditions, and after dissolution, the volume of these substances significantly shrinks. Fourth, supercritical water displays an extraordinary catalytic effect, greatly accelerating the rate of catalytic reactions. The numerous advantages of supercritical water have made it a valuable tool for researchers.

Control Methods for Temperature Precision in Laboratory Reactor Operation

Weihai Self-Control Reactor Co., Ltd. specializes in the manufacture of laboratory reactors with a high degree of control. Regarding the temperature control accuracy of reactors used during customer experiments, the following methods can be employed to improve it: 1. For laboratory reactors with smaller vessel volumes and operating at very high temperatures, the temperature control accuracy is primarily achieved through segmented temperature control via intelligent programs on the temperature controller. During operation, the temperature controller performs PID self-tuning, ensuring that the temperature is tentatively heated and controlled around the setpoint temperature of the equipment. This temperature-control method typically achieves an accuracy of about 1 to 1.5 degrees Celsius, making it well-suited for applications where precise temperature control is required but not extremely stringent.

General requirements for level gauges installed on high-pressure reactors

High-pressure reactors sometimes need to be equipped with level gauges according to customer requirements. The general requirements for installing level gauges are as follows: 1. The level gauge should be selected based on the medium of the high-pressure reactor, the maximum allowable working pressure (or design pressure), and the design temperature. 2. Before using the level gauge, for equipment with a design pressure less than 10.0 MPa, a hydraulic test shall be conducted at 1.5 times the nominal pressure of the level gauge; for equipment with a design pressure equal to or greater than 10.0 MPa, a hydraulic test shall be conducted at 1.25 times the nominal pressure of the level gauge. 3. For high-pressure reactors storing materials at temperatures below 0 degrees Celsius, frost-resistant level gauges should be selected.

Replacement Standards for Pressure Gauges Used in High-Pressure Reactors

The pressure gauges used on high-pressure reactors must be replaced under the following circumstances: 1. For pressure gauges with limiting pins on high-pressure reactors, if the pointer fails to return to the limiting pin position when there is no pressure, or for pressure gauges without limiting pins, if the distance between the pointer and zero exceeds the allowable error of the gauge when there is no pressure. 2. If the glass cover of the dial is broken or the scale markings on the dial are blurred and unclear. 3. If the seal is damaged or the calibration validity period has expired. 4. If there is leakage from the spring tube inside the pressure gauge used on the high-pressure reactor, or if the gauge’s pointer becomes loose. 5. If the pointer is broken or the casing is severely corroded. 6. Any other defects that affect the accurate indication of the pressure gauge.

Installation and Use of Magnetic Stirred Reactors

Host Installation and Operation (1) Equipment Environment: The magnetic stirrer reactor should be placed in a high-pressure operating room that meets explosion-proof requirements. When installing multiple magnetic stirrer reactors, they should be arranged separately, with reliable explosion-proof walls providing separation between every two reactors. Each operating room must have an exit directly leading to the outside or to a passageway. If explosive media are present, the equipment location must be well-ventilated. (2) Installation and Sealing of the Reactor Lid: The reactor body and the reactor lid adopt a sealing design featuring line contact between conical and arc surfaces. Tighten the main bolts to ensure that the two components are firmly pressed against each other, achieving a reliable seal. When tightening the main bolts, do not exceed the specified torque limit.

Application Characteristics of High-Pressure Reactors for Nickel and Nickel-Based Alloys (Part 1)

High-pressure reactors made of nickel and nickel alloys exhibit superior corrosion resistance to strong acids, strong bases, and other highly corrosive media compared to those made of stainless steel and other non-ferrous metals. They also operate at higher service temperatures, making them one of the most important types of high-pressure reactors currently available. When using high-pressure reactors made of nickel and nickel-based alloys, attention should be paid to the following points regarding their allowable operating temperatures: 1. If the reactor is constructed from a nickel alloy whose primary alloying elements are chromium or molybdenum, and the service conditions of the vessel’s medium could potentially induce intergranular corrosion in these nickel alloys, the maximum allowable operating temperature of the equipment should not exceed the long-term aging temperature that would increase the susceptibility of these nickel alloys to intergranular corrosion.

Key Considerations for Selecting a Pilot-Scale Hydrogenation Autoclave

The pilot-scale hydrogenation autoclave is a product positioned between laboratory hydrogenation autoclaves and industrial hydrogenation autoclaves. Its key distinguishing feature is its larger volume compared to laboratory autoclaves. Moreover, since hydrogenation or hydriding reactions can be highly exothermic, the pilot-scale hydrogenation/hydriding autoclave is equipped with explosion-proof features for both the stirring motor and the electric heating system. Additionally, due to the increased aperture size, laboratory autoclaves typically feature open-top designs, whereas pilot-scale autoclaves are no longer limited to closed designs. Instead, influenced by factors such as pressure, temperature, and volume, they often adopt closed structures. In terms of converting design pressure into working pressure, hydrogenation autoclaves also differ from conventional autoclaves.

Key points for non-destructive testing of the surface of industrial high-pressure reactors

Magnetic particle testing and penetrant testing are both surface nondestructive testing methods. Surface nondestructive testing of welded joints in industrial high-pressure reactors should be conducted according to the following key points: 1. Surface nondestructive testing shall be performed on welded joints of high-pressure reactors whose design temperature is below -40°C. 2. Welded joints on high-pressure reactors made of stainless steel with a minimum specified tensile strength of 540 MPa or higher. 3. Welded joints on high-pressure reactors made of austenitic stainless steel with a weld joint thickness exceeding 20 mm. 4. Welded joints on high-pressure reactors made of Cr-Mo low-alloy steel with a weld joint thickness exceeding 16 mm. 5. Stack