HEAT EXCHANGER CLEANING METHOD

 Autumn and winter are the peak of heat exchanger selection every year. Before the peak of selection, the long-term heat exchanger must be repaired and removed.

The heat exchanger is a kind of compact and high-efficiency heat transfer equipment. It is a kind of excellent heating, cooling, recycling and rapid sterilization equipment. But I don’t know that due to the long-term operation of the heat exchanger, the difference in the purity of the cooling or heating side, and the difference in the material characteristics of the processing technology, the fouling of the heat exchanger has long been unavoidable, resulting in the heat transfer The thermal efficiency is reduced, thereby endangering all normal production and processing and safety factors of machinery and equipment. Therefore, the heat exchanger should be removed on time to remove stains and ensure high efficiency heat transfer and normal production.

One, the choice of heat exchanger cleaning method

According to the different cleaning methods, the key cleaning methods are physical cleaning and chemical cleaning.

Chemical cleaning

Chemical cleaning is a type of chemical change caused by a chemical cleaning fluid, which can decompose, remove or get rid of the scale and other deposits on the surface of the heat exchanger. Chemical cleaning does not require disassembly and assembly of heat exchangers, which simplifies the entire cleaning process and eases the level of labor for cleaning. The disadvantage is that when a poor chemical cleaning solution is selected, the cultivation substrate from which the raw material is removed will be harmed and cause damage.

Chemical cleaning method

Circulation method: Use a pump to forcefully clean the liquid circulation system for removal.

Dipping method: Spread the cleaning solution over the machine and equipment, and leave it for a corresponding period of time.

Surge method: Spread the cleaning liquid over the machine and equipment, discharge a part of the cleaning liquid from the bottom for a corresponding interval, and then load the discharged liquid back into the machine and equipment to ensure the practical significance of stirring and cleaning.

(1) Protect machinery and equipment, and clean the water in the heat exchanger.

(2) Clean the pipeline dirt with high pressure water and close the system.

(3) Install a gate valve in the middle of the protective valve and the air conditioner exchanger, connect the stirring pump and hose, and pump the cleaning agent from the bottom of the heat exchanger and discharge it from the top.

(4) Introduce the necessary cleaning agent and continue to circulate the system to remove it.

(5) Exhaust gas at any time and introduce moderate water.

(6) Use PH test paper to measure the pertinence of cleaning agent.

(7) Recover and remove the aqueous solution and continue cleaning with clean water until the pH is neutral.

Physical removal

Physical removal is to smash, extract and get rid of the surface of small objects by means of various mechanical external forces and heat generation, thereby ensuring the expected effect of removal. The physical removal methods all have one thing in common: high efficiency, corrosion resistance, safety factor, ecological environment protection. The disadvantage is that when cleaning the inside of complicated machinery and equipment, the force sometimes cannot guarantee all parts evenly, causing "blind spots".

A wide range of methods include ultrasonic scale cleaning, PIG cleaning professionalism, and electrostatic field scale cleaning professionalism.

High pressure water jet cleaning

The high-pressure water caused by the plunger pump is sprayed to the scale layer through a unique nozzle. The scale is cleaned thoroughly and efficiently. However, the container is large and the water consumption is large.

Ultrasonic scale cleaning

It mainly uses ultrasonic sound field to deal with fluid mechanics, so that the scale-forming substance of fluid mechanics will cause a series of changes in its physical shape and chemical characteristics under the action of ultrasonic field, so that it will be dispersed, crushed, loosened, loosened and not easily adhered to wall thickness. Of fouling.

Movable scale cleaning equipment in pipeline scale cleaning

The mobile scale cleaning equipment in the new pipeline has high efficiency and high quality. It can be used for scale cleaning in gas transportation pipelines and liquid and water transportation pipelines in chemical plants.

According to the failure of the driving method, the widespread mobile scale cleaning equipment in the pipeline is divided into: A. Electric power engineering-driven mobile scale cleaning equipment; B. Hydraulic drive driven mobile scale cleaning equipment; C. Air compression driven mobile scale cleaning equipment Cleaning equipment.

Mechanical removal

It relies on mechanical action to provide a force higher than the adhesion of stains so that the stains fall from the heat transfer surface. This type of method can remove carbonized stains and hard dirt that cannot be removed by chemical methods, but it is generally necessary to remove the dirt layer in the cleaning pipe 5-6 times, sometimes as high as 10 times, and the pigging efficiency is low and the quality is poor.

Microbial removal

Microbial removal is a method of using microorganisms to decompose the oil stains attached to the surface of machinery and equipment, and transform them into non-toxic and harmless water-soluble substances. This type of cleaning completely decomposes air pollutants (such as raw oil) and organic compounds, which is a kind of energy-saving cleaning professional in the true and practical sense.

Both physical cleaning and chemical cleaning have their own advantages and disadvantages, and they have good diversification. In fact, in the whole process of application, the two are generally combined to obtain a stronger elimination of the expected effect.

For chemical cleaning methods, the choice of cleaning agent has a significant impact on the expected cleaning effect.