In the clean engineering, the selection of ventilation ducts in Shandong is very important. The cleanliness and airtightness of the pipeline itself are very high. Because the wind pressure in the ventilation ducts in the clean air conditioner is doubled compared with that of the ordinary air conditioner, everyone can't pay attention to it.
I. Reviewing the large-scale development of China's purification air-conditioning industry began in the mid-1970s. “The purification of air-conditioning was a new topic for most people at that time. Everyone attaches great importance to it. Of course, in engineering applications. We also attach great importance to the ventilation ducts; the cleanliness and airtightness of the pipeline itself are very high. Because the wind pressure in the ventilation ducts in the clean air conditioner is doubled compared with the ordinary air conditioners, so we can’t pay attention to it; The cleanliness and air tightness of the pipeline directly affect the operation of the entire purification system. It affects the wind pressure, air volume and even airflow organization, cleanliness, operating power and noise of the system.
At that time, due to the underdevelopment of the basic materials, the selection of the preferred materials was quite narrow. The use of steel-zinc steel plates for Shandong ventilation pipes was very advanced (at that time, most air conditioners used black steel plates to make pipes). Due to the high enthusiasm of the workers and the strong sense of responsibility, the craftsmanship is also very good. The airtightness of the pipes such as the mouthpiece and the flange connection made by the workers is quite good. The protective layer is also very regular.
The remains are still in use today. They are also made of steel-zinc steel plate bitings to make angled steel flange joints. The quality of the pipes is sometimes not guaranteed. As pointed out in the investigation report: if the bite is not seamed After the treatment, the air leakage is more than 50%, and the maximum air leakage is 13%. This is a big waste in operation. However, in actual engineering, how many construction units seriously handle this bite? ?
Second, how to ensure the quality of the above-mentioned pipeline can not be guaranteed. I also asked us a question: Why do the above-mentioned serious quality problems still exist after everyone generally believes that science and technology are progressing? This requires us to The problem must have a lieutenant analysis. The advancement of this technology is mainly reflected in the advancement of materials, the advancement of machines, equipment, and tools. The skills of using simple tools while working on machines, equipment, and tools are not necessarily improved, and the responsibility of laborers for economic purposes may not be enhanced;
With such analysis, it is not difficult to judge that the above-mentioned quality problems are mostly in companies that do not have advanced machinery and equipment, advanced technology, and are mainly operated by hand. That is to say, in order to obtain high-performance and stable quality assurance, it is necessary to proceed from the mechanization and mold-making of pipeline production, and must proceed from the standardization of the process to try to avoid the manual operation.
Third, the progress of materials - this scientific and technological achievements should be reflected in the production of pipelines: Progress in materials is an important aspect of scientific and technological progress. Advances in materials also directly affect the progress of the work methods, and directly affect the stability of product quality. This should also follow this rule for our ventilation ducts for air conditioning. I mentioned in front of this: From the initial earthquake of the cold air conditioning industry to the present 30 years, the ventilation ducts used for purifying air conditioners are basically based on the original raw materials. This is not a pity. In the production of steel-zinc steel pipe, the use of mechanized production by the company is no longer a problem (the airtightness of the bite slit is another matter), but the insulation process is so cumbersome, the installation workers are so tired and the quality is not easy. The status quo of the guarantee has still not been resolved.
In recent years, the emergence of a new thermal insulation material, a rubber and plastic material, has reduced the labor intensity of workers, but it has not been able to get rid of its backward labor methods. The current price of this material is relatively expensive and cannot be widely used. In the past few years, in the general air-conditioning, the glass fiber duct, the glass fiber reinforced plastic duct and some imported composite ducts have been applied. It should be said that the appearance of composite ducts is an improvement in the ventilation duct industry. Of course, the form, nature and processing technology of these materials are not suitable for the requirements of purification engineering. Therefore, it has not been able to be shocked in the purification project. However, the appearance of composite materials in the wind pipe industry is an improvement anyway. It is a kind of shocking composite material that is a trend in the world. It can also be said that it is an inevitable result of industrial progress. Therefore, the Shandong ventilation duct for purifying air conditioners should also use composite materials.
Fourth, the composite material duct has the following advantages: The composite material and its accessories can solve many problems of the traditional duct:
1. Insulation In the traditional air duct construction, the heat preservation process is the most difficult and most annoying, so the quality of the insulation is not guaranteed. Because it is directly affected by the mood, responsibility and technical proficiency of the workers. The influence of the ventilating surface of the ventilating duct and the insulating layer are bonded and bonded together, so that the pipe does not need to be insulated after the pipe is made. This easily solves the above-mentioned heat preservation problem, and saves a lot of man-hours due to the removal of the heat preservation process, thereby greatly reducing the labor cost in the pipe cost.
2. Air tightness problem The traditional steel plate pipe is formed by bite forming. The air leakage of the angled steel flanges at both ends of the pipe section generally occurs in these three parts - the intersection line - the joint of the steel plate and the flange. The joint with the flange. These joints of composite ducts are much better than steel ducts. Of course, the airtightness is much better. This is mainly because the processing technology has completely changed. The bridging of the composite duct pipe is based on the bond, the bond bar is used instead of the bite bar, and the contact surface of the material in the bond bar is wider and is in contact with the material in the bite of the flexible joint. The narrower surface is relatively rigid joints (of course, plastic deformation components). Therefore, the degree of airtightness can be imagined. The composite duct is equipped with a slotted closed flange (to be detailed), which makes the airtightness of the end of the composite duct more secure.
3 振动Vibration problem The vibration of the pipeline                                         ç®¡é“ ç®¡é“ ç®¡é“ ç®¡é“ ç®¡é“ ç®¡é“It seems that the surface of the cymbal is not flat or concave or protruding. When the system is running, especially when the fan is turned on, it will produce the sound of a dome, like a drum. The muffler in this sound system is It is not easy to eliminate the main original group. The rigidity of the galvanized steel sheet is not good and the processing size of the blanking is not accurate.
Composite materials can solve this problem. The fundamental reason is that the rigidity of the composite material is good. During the blanking and bonding process, there is no material or the surface of the pipe is concave and convex, which eliminates the internal cause of self-shock. The composite material also has superiority in shock absorption. Since the ventilating surface and the thermal insulation layer of the pipe are bonded by one-time bonding, the thermal insulation material is generally elastic, and it dampens the vibrating surface of the vibration. The role of absorption. The use of composite materials makes it possible to mechanize the production of ducts. This will greatly improve the overall quality of the ducts.
V. Current Status of Composite Ducts in China There are two types of composite ducts that can be used at present: glass fiber ducts and fiberglass ducts with insulation (Bray Steel itself is not a composite material). There are also two kinds of imported air ducts. One is the American fiberglass duct, the other is the Italian polyurethane composite duct. The outer surfaces of these composite wind foods are all aluminum foil, and their commonality is good. The strength is not good. For various reasons, these ducts are rare in actual cleanliness projects.
Sixth, the emerging double-sided color plate composite duct now introduces a composite duct that can be used for purification engineering - double-sided color plate composite duct as its name suggests. Double-sided color plate composite duct is the two surfaces for color steel The composite material of the air duct and the intermediate composite made of the composite plate of the aluminum plate may be a flame retardant polystyrene, a polyurethane plate or a fiberglass plate. The composite air pipe has the following characteristics:
1. Although the board is used for the first time in the production of ducts, the production of such materials is quite common. The process is quite mature, the quality is guaranteed, and the source of supply is sufficient.
2. The rigidity of the composite plate is good and the surface strength is the strength of the steel plate. Due to the characteristics of the composite plate, when manufacturing a large-diameter air duct or when it is used for a high-pressure air duct such as a cold-condensing system, Generally, there is no need to specially protect the ribs. This makes the entire air duct network clean and neat. At the same time, the production and installation of the air duct saves labor, saves time and saves materials, so that the relative cost is reduced.
3. The air duct produced is smooth and flawless, and it is not dust-prone and dust-free. It is especially suitable for clean engineering. The surface of the steel-plastic layer is much better than steel and zinc steel. Because of its good weather resistance, it is much better than other pipes in high temperature and high humidity environment, and even in other places. It is also suitable for the installation of pipes when it is bright and beautiful.
4. The production of composite air ducts needs mechanization. This makes the accuracy of the ventilation ducts in Shandong and the related quality guaranteed, so that the pipes of the same size are interchangeable and the production efficiency is improved. This means that The total cost of the air duct will be greatly reduced. The construction party will get more benefits in the investment of the air duct:
5. The color plate composite air duct will be equipped with PVC closed groove flange to make the combination of the pipe and the flange more tight. The flange connection surface has a ring sealing groove, and a flexible rubber strip is placed inside the pipe. The airtightness of the pipe connection is guaranteed;
6. The connection of the PYC trough type closed flange is a card type connection. The construction is simple, fast, labor-saving and labor-saving, saving installation space, especially suitable for installation in narrow space;
7. The use of PVC flange not only realizes the mechanization of flange production, standardizes the process, but also completely solves the problem of “cold bridge†in the pipeline.
8. The double-sided color plate composite board can also be used as the valve body and then with the PVC flange to solve the problem of reheating the original tough valve, so that the whole pipeline system is colored.
Here, I also recommend that the reverse self-locking valve should be developed vigorously. Its mechanism is simple and reliable, no need to lock it, and the blade position is stable. 
Development of Shandong Ventilation Pipeline in Purifying Air Conditioning