A cleaning agent for melamine production system scar block

Abstract

The present application belongs to the technical field of chemical production, and particularly relates to a cleaning agent for scar blocks in a melamine production system. The cleaning agent comprises the following raw materials in parts by weight: deionized water 20-40 parts, isopropyl alcohol 20-50 parts, DMSO solvent 1-10 parts, oxalic acid 5-20 parts, and anhydrous ethanol 1-10 parts. The cleaning agent is simple to prepare, the raw materials are cheap and easy to obtain, and the amount of the cleaning agent is small. The cleaning agent mainly comprises common organic solvents, is easily adsorbed by the scar blocks, and is easy to recycle and process. The cleaning agent is easy to use, has a remarkable cleaning effect, can be repeatedly used, and the waste liquid and waste produced during the cleaning process are easy to collect and process.

Description

Technical Field

[0001] This invention belongs to the field of chemical production technology, specifically a cleaning agent for blemishes in melamine production systems. Background Technology

[0002] Melamine is a very important organic chemical intermediate with a wide range of applications. It is mainly used in the synthesis of melamine-formaldehyde resin, and in the manufacture of everyday utensils, decorative panels, textile finishing agents, high-performance environmentally friendly coatings, and flame-retardant materials. Currently, the most common production process is the urea method: urea is melted at high temperature, and the molten urea, using ammonia as a carrier and silica-alumina gel as a catalyst, undergoes a boiling reaction at 380-400℃. It first decomposes to produce cyanic acid, which further condenses to produce melamine. The generated melamine gas is cooled and collected to obtain a crude product, which then undergoes quenching, stripping, filtration, crystallization, and drying to remove impurities, yielding the finished melamine product [6CO(NH2)2→C3N6H6+6NH3+3CO2].

[0003] As can be seen, the urea-based melamine production process is lengthy and involves numerous pieces of equipment. Due to the nature and characteristics of chemical production processes, reactors and pipelines in the system are in constant contact with materials. Material adheres to and accumulates on the walls of reaction vessels and pipelines over time. After a period of operation, material deposits, commonly known as "sludge," eventually form on the vessel and pipe walls. This accumulation leads to lower production efficiency, higher energy consumption, and increasingly unstable and deteriorating product quality. As the sludge thickens, it can even cause blockages in valves and narrow sections of pipelines, leading to major safety accidents such as emergency system shutdowns. Therefore, melamine production systems require shutdown and maintenance after a period of operation. The most important task is cleaning the sludge from the reaction vessel and pipeline walls to reduce resistance to material flow, stabilize product quality, improve production efficiency, and eliminate safety hazards.

[0004] Because the main component of the blemishes is melamine, an organic chemical product, they accumulate and harden over a long period in a high-temperature, high-pressure system environment. This hardening makes them firmly bonded to the container and pipe walls, rendering them impossible to remove with high-pressure gas or water jets. Currently, the primary method remains manual cleaning. Cleaning personnel must enter the container and use tools such as electric picks and putty knives to break and remove the blemishes in the confined space. This is particularly difficult in narrow pipes, resulting in incomplete cleaning and high safety risks. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present invention develops a cleaning agent for melamine production system (such as reactor and pipe wall) based on the characteristics of melamine production sludge. This agent can make the sludge cleaning more thorough and the cleaning work easier.

[0006] To achieve the above-mentioned objectives, the specific technical solution of this invention is as follows:

[0007] A cleaning agent for blemishes in a melamine production system comprises the following raw materials in parts by weight: 20-40 parts deionized water, 20-50 parts isopropanol, 1-10 parts DMSO solvent, 5-20 parts oxalic acid, and 1-10 parts anhydrous ethanol.

[0008] As a preferred embodiment of this application, the cleaning agent for melamine production system comprises the following raw materials in parts by weight: 30 parts deionized water, 40 parts isopropanol, 2 parts DMSO solvent, 18 parts oxalic acid, and 10 parts anhydrous ethanol.

[0009] As a preferred embodiment of this application, the cleaning agent for melamine production system comprises the following raw materials in parts by weight: 35 parts deionized water, 40 parts isopropanol, 5 parts DMSO solvent, 15 parts oxalic acid, and 5 parts anhydrous ethanol.

[0010] As a preferred embodiment of this application, the cleaning agent for melamine production system comprises the following raw materials in parts by weight: 30 parts deionized water, 50 parts isopropanol, 4 parts DMSO solvent, 10 parts oxalic acid, and 6 parts anhydrous ethanol.

[0011] As a preferred embodiment of this application, the cleaning agent for melamine production system comprises the following raw materials in parts by weight: 35 parts deionized water, 40 parts isopropanol, 8 parts DMSO solvent, 12 parts oxalic acid, and 5 parts anhydrous ethanol.

[0012] As a preferred embodiment of this application, the preparation method of a cleaning agent for melamine production system includes the following steps: weighing according to the specified amount, and then adding deionized water, isopropanol, DMSO solvent, oxalic acid and anhydrous ethanol in the order of addition and mixing evenly to obtain the final product.

[0013] As a preferred embodiment of this application, the cleaning agent for blemishes in a melamine production system is used in a urea-process melamine production system as a cleaning device for cleaning blemishes on reactor or pipe walls.

[0014] This invention involves a variety of organic solvents, which pose certain risks. Safety precautions should be taken throughout the entire process of its use.

[0015] As a preferred embodiment of this application, the method for applying the cleaning agent for melamine production system flakes includes the following steps: adding the prepared agent to an anti-corrosion sprayer, with a spraying volume of 5-20 kg / 50-100 m³. 2 (i.e., 50-100m) 2 The dosage of the agent is 5-20 kg. After waiting for 10-30 minutes, the scar will break down into powder or small pieces and fall off under the action of the agent. Then, use high-pressure air or a high-pressure water gun to wash away the fallen scar material.

[0016] Furthermore, the sprayer is equipped with an extended tube and a 360° atomizing nozzle, depending on the equipment. The agent is sprayed evenly onto the scabs on the container or pipe wall in a sequence from bottom to top and from far to near. The application is repeated 2 to 3 times depending on the cleaning effect.

[0017] Compared with the prior art, the positive effects of the present invention are reflected in:

[0018] (i) A cleaning agent for melamine production system for removing sludge. The agent is simple to prepare, uses inexpensive and readily available raw materials, and requires a small amount. The agent is mainly a common organic solvent, which is easily adsorbed by the sludge and is easy to recycle.

[0019] (ii) The cleaning agent of the present invention is easy to use, has a significant cleaning effect, can be reused, and the waste liquid and waste generated during the cleaning process are easy to collect and handle. Attached Figure Description

[0020] Figure 1 This is a diagram of the blemishes present in the container and pipe walls.

[0021] Figure 2 The diagram shows the disintegration and dissolution of blemishes after cleaning with a cleaning agent for blemishes in a melamine production system according to the present invention.

[0022] Figure 3 This is a comparative diagram of experiments using other agents during the formulation development process. Detailed Implementation

[0023] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0024] Any feature disclosed in this specification (including the claims and abstract) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments. The embodiments of the present invention include, but are not limited to, the following embodiments.

[0026] In this application, unless otherwise specified, all percentages are mass percentages, i.e., wt%. All reagents used in the cleaning agents are commercially available products.

[0027] Example 1:

[0028] The melamine production system was shut down according to the maintenance procedure, and safety work such as purging, gas replacement, and connection / disconnection was completed as required, meeting the requirements for cleaning. Waste collection buckets or other containers were set up at the bottom of the container and at the end of the pipeline outlet, and safety signs were affixed.

[0029] A cleaning agent for melamine production system sludge removal is prepared as follows: Weigh 30 kg of deionized water and add it to a container equipped with a stirrer. Start the stirrer. Then, weigh 40 kg of isopropanol, 2 kg of DMSO solvent, 18 kg of oxalic acid, and 10 kg of anhydrous ethanol separately and add them to the stirrer in sequence. After all materials have been added, stir for at least 30 minutes to ensure uniform mixing.

[0030] Prepare a sprayer with anti-corrosion function. The sprayer should be equipped with an extended tube with anti-corrosion function (to facilitate spraying to the bottom) and a 360° atomizing nozzle, depending on the equipment and pipeline conditions.

[0031] Construction workers should take necessary safety precautions and wear appropriate protective equipment as required. The prepared cleaning agent should be poured into the atomizer (spray rate: 12kg / 70m²). 2 The agent is evenly sprayed onto the scars on the container walls and pipe walls in an order from bottom to top and from far to near.

[0032] After waiting for about 20 minutes, the scabs will break down into powder or small pieces under the action of the agent and fall off the container and pipe walls. Use high-pressure air or a high-pressure water gun to clean off the detached scabs. Repeat the cleaning 2 to 3 times depending on the cleaning effect until there are no scabs attached to the container and pipe walls.

[0033] The cleaned-up waste materials should be collected and disposed of in accordance with relevant regulations for industrial waste. (Those washed with water should be separated into solid and liquid components according to regulations.)

[0034] Example 2:

[0035] The operating steps of Example 2 are the same as those of Example 1, except that when preparing a cleaning agent for melamine production system sludge, 35 kg of deionized water is weighed and added to a container equipped with a stirrer. The stirrer is then started. Next, 40 kg of isopropanol, 5 kg of DMSO solvent, 15 kg of oxalic acid, and 5 kg of anhydrous ethanol are weighed and added to the stirrer in sequence. After all materials have been added, the mixture is stirred for at least 30 minutes to ensure uniform mixing.

[0036] The spraying rate is 15 kg / 80 m. 2 After treatment, no scars or blemishes remained on the container and pipe walls.

[0037] Example 3:

[0038] The operating steps of Example 3 are the same as those of Example 1, except that when preparing a cleaning agent for melamine production system blemishes: 30 kg of deionized water is weighed and added to a container equipped with a stirrer. The stirrer is started. Then, 50 kg of isopropanol, 8 kg of DMSO solvent, 12 kg of oxalic acid, and 5 kg of anhydrous ethanol are weighed and added to the stirrer in sequence. After all materials have been added, the mixture is stirred for at least 30 minutes to ensure uniform mixing.

[0039] The spraying rate is 18 kg / 80 m. 2 After treatment, no scars or blemishes remained on the container and pipe walls.

[0040] Example 4:

[0041] The operating steps of Example 4 are the same as those of Example 1, except that when preparing a cleaning agent for melamine production system blemishes: 35 kg of deionized water is weighed and added to a container equipped with a stirrer. The stirrer is started. Then, 40 kg of isopropanol, 8 kg of DMSO solvent, 12 kg of oxalic acid, and 5 kg of anhydrous ethanol are weighed and added to the stirrer in sequence. After all materials have been added, the mixture is stirred for at least 30 minutes to ensure uniform mixing.

[0042] The spraying rate is 15 kg / 80 m. 2 After treatment, no scars or blemishes remained on the container and pipe walls.

[0043] Comparative Example 1:

[0044] The operation of Comparative Example 1 is the same as that of Example 1, except that when preparing a cleaning agent for melamine production system sludge, 30 kg of deionized water is weighed and added to a container equipped with a stirrer. The stirrer is started, and then 50 kg of sodium hydroxide and 5 kg of anhydrous ethanol are weighed and added to the stirrer in sequence. After all materials have been added, the mixture is stirred for at least 30 minutes to ensure uniform mixing.

[0045] It was found that after spraying in the manner described in Example 1, there was no reaction on the container wall and pipe wall, and spraying 2-3 more times had no effect.

[0046] Comparative Example 2:

[0047] The operation of Comparative Example 2 is the same as that of Example 1, except that when preparing a cleaning agent for melamine production system sludge, 30 kg of deionized water is weighed and added to a container equipped with a stirrer. The stirrer is then started. Then, 40 kg of isopropanol, 18 kg of oxalic acid, and 10 kg of hydrochloric acid are weighed and added to the stirrer in sequence. After all materials have been added, the mixture is stirred for at least 30 minutes to ensure uniform mixing.

[0048] After spraying in the manner described in Example 1, no reaction was observed on the container wall and pipe wall. After spraying 2-3 more times, the surface scabs slightly peeled off.

[0049] Comparative Example 3:

[0050] The operation of Comparative Example 3 was the same as that of Example 1, except that when preparing a cleaning agent for melamine production system sludge, 30 kg of deionized water was weighed and added to a container equipped with a stirrer. The stirrer was started, and then 10 kg of anhydrous ethanol, 18 kg of oxalic acid, and 10 kg of diethyl ether were weighed and added to the stirrer in sequence. After all materials were added, the mixture was stirred for at least 30 minutes to ensure uniform mixing.

[0051] It was found that after spraying in the manner described in Example 1, there was no reaction on the container wall and pipe wall, and spraying 2-3 more times had no effect.

[0052] Comparative Example 4:

[0053] The operation of Comparative Example 4 was the same as that of Example 1, except that when preparing a cleaning agent for melamine production system sludge, 30 kg of deionized water was weighed and added to a container equipped with a stirrer. The stirrer was started, and then 10 kg of anhydrous ethanol, 18 kg of acetone, and 10 kg of ethanol were weighed and added to the stirrer in sequence. After all materials were added, the mixture was stirred for at least 30 minutes to ensure uniform mixing.

[0054] It was found that after spraying in the manner described in Example 1, there was no reaction on the container wall and pipe wall, and spraying 2-3 more times had no effect.

[0055] experiment:

[0056] In order to find a safer, easier, more convenient and more efficient cleaning method, we tested various physical methods such as detonation, ultrasonic cleaning, and electric ball brushes. We found that these physical methods were not only complicated to operate and required high-end tools, but also did not clean thoroughly and caused significant damage to the equipment.

[0057] We then attempted to find chemical solvents to solve the problem, using common organic and inorganic solvents such as sodium hydroxide, diethyl ether, DMSO, carbon tetrachloride, carbon disulfide, acetone, hydrochloric acid, concentrated nitric acid, and ammonia to conduct dissolution experiments on the scars; the specific results are shown in [link to results]. Figure 3 . Figure 3 This is a comparative chart showing the experimental effects of dissolving scar tissue using sodium hydroxide, ether, DMSO, carbon tetrachloride, carbon disulfide, acetone, hydrochloric acid, concentrated nitric acid, and ammonia alone during the research and development process. Figure 3 It can be seen that using these conventional organic and inorganic solvents alone is less effective than the cleaning agent in this invention in dissolving the scale on the container and pipe walls.

[0058] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. The present invention extends to any new feature or any new combination disclosed in this specification, as well as any new method or process step or any new combination disclosed.

Claims

1. The application of a cleaning agent in cleaning blemishes in a melamine production system, characterized in that, This cleaning agent is made from the following raw materials in parts by weight: 20-40 parts deionized water, 20-50 parts isopropanol, 1-10 parts DMSO, 5-20 parts oxalic acid, and 1-10 parts anhydrous ethanol. This cleaning agent is used in the urea process for producing melamine to clean reactor or pipe wall scale. The application method is as follows: Add the prepared agent to the corrosion-resistant sprayer, and spray at a rate of 5-20 kg / 50-100 m². 2 After waiting 10-30 minutes, the scar will break down into powder or small pieces and fall off under the action of the medicine. Then, use high-pressure air or a high-pressure water gun to rinse off the fallen scar material.

2. The application as described in claim 1, characterized in that... It is made from the following raw materials in parts by weight: 30 parts deionized water, 40 parts isopropanol, 2 parts DMSO, 18 parts oxalic acid, and 10 parts anhydrous ethanol.

3. The application as described in claim 1, characterized in that... It is made from the following raw materials in parts by weight: 35 parts deionized water, 40 parts isopropanol, 5 parts DMSO, 15 parts oxalic acid, and 5 parts anhydrous ethanol.

4. The application as described in claim 1, characterized in that... It is made from the following raw materials in parts by weight: 30 parts deionized water, 50 parts isopropanol, 8 parts DMSO, 12 parts oxalic acid, and 5 parts anhydrous ethanol.

5. The application as described in claim 1, characterized in that... It is made from the following raw materials in parts by weight: 35 parts deionized water, 40 parts isopropanol, 8 parts DMSO, 12 parts oxalic acid, and 5 parts anhydrous ethanol.

6. The application as described in any one of claims 1-5, characterized in that... The process includes the following steps: weighing the ingredients according to the specified amounts, then adding them in the order of deionized water, isopropanol, DMSO, oxalic acid, and anhydrous ethanol and mixing them thoroughly; the mixing time should be at least 30 minutes.

7. The application as described in claim 1, characterized in that: The sprayer is equipped with an extended tube and a 360° atomizing nozzle, depending on the equipment. The agent is sprayed evenly onto the scabs on the container or pipe wall in a sequence from bottom to top and from far to near. The application is repeated 2 to 3 times depending on the cleaning effect.

Images