1. Is the current market cold or hot? — — Real voices on both sides of supply and demand
What is the market of desulfurization non-metallic compensator? This question, I just talked with the purchase of several desulfurization projects last week. To be honest, the market is not simply cold or hot now, but sharply differentiated.
Look at the demand side first. In the final stage of ultra-low emission transformation of domestic thermal power, steel and cement industries, there are indeed fewer replacement parts for old projects, but what about new projects? In coking, chemical and waste incineration industries, desulfurization systems are still being launched. Especially for some central heating projects in industrial parks, the standard equipment of flue gas desulfurization is non-metallic compensator. From the inquiry volume, the first half of this year increased by about 15% compared with the same period of last year-mainly supported by small and medium-sized projects.
Look at the supply side again. Small and medium-sized compensator manufacturers are having a hard time. The price increase of raw materials is on the one hand, and more importantly, the payment cycle has been extended to 6 months or even one year, and many factories dare not take big orders. However, the head enterprises are expanding production instead, because end users are becoming more and more picky: not any non-metallic expansion joint can be exported to the desulfurization tower.
So you have to ask whether the market is hot or cold? For manufacturers who can come up with the new national standard and have actual operating performance, the order is scheduled for three months; For factories that are still making up numbers with old fabric fibers, they can only rely on low prices to grab bulk orders, and their profits are as thin as paper.
Second, driven by the policy, what hard indicators does the desulfurization system put forward for non-metallic compensators?
The environmental protection policy has not been loosened in recent years. In 2023, the Ministry of Ecology and Environment revised the Air Pollutant Emission Standard for Thermal Power Plants, which directly forced the upgrading of the desulfurization system. What used to be made do with metal expansion joints is now required to be replaced with non-metallic ones-for a simple reason: corrosion resistance, zero leakage, and the ability to absorb multidimensional displacement.
- Temperature resistance class must be defined: The temperature of the original flue gas side of desulfurization is generally 120~160℃, but it may rush above 200℃ when encountering bypass conditions. The skin of the non-metallic compensator (that is, the fabric fiber layer) must give a third-party inspection report to prove that it will not fail after continuous operation for 10,000 hours at the set temperature. Don't trust the manufacturer's verbal promise, ask for paper documents.
- Sealability Requirements: The new design code requires a compensator leak rate of less than 0.1%. By what? Multi-layer construction + fluororubber sealing layer. Like the one in our stationNon-metallic expansion joint (fabric fiber expansion joint)It is made of fluororubber, polytetrafluoroethylene and glass fiber fabric, and is sealed in three layers. Before leaving the factory, air tightness test is done one by one.
- Anti-corrosion requirements: The wet flue gas after desulfurization contains acidic condensate water, and the pH value can be as low as 2. If the interior of the compensator uses a carbon steel frame, it must be lined or enameled to a high standard. Some projects specify stainless steel frames lined with PTFE, which is costly but long-lasting.
These hard indicators directly determine the difference in procurement cost by more than 30%. But there is no way, the acceptance fails, and rework is more expensive.
Third, buy it or buy a metal expansion joint? — — The irreplaceability of non-metallic compensators in desulfurization scenarios
Why don't metal corrugated expansion joints be used directly for desulfurization flue? It is cheap and has a high pressure resistance.
Alas, I've seen this pit too many times. The diameter of the desulfurization flue pipe is large (DN1000~ DN4000 is very common), and it is low pressure (usually below 0.1MPa) and large displacement (axial energy reaches 50mm and transverse energy is more than 20mm). The metal corrugated expansion joint has two dead points under this working condition: First, the thrust is huge, and the pipe support can't stand it; Second, it is easy to crack by stress corrosion-the bellows has a thin wall, and it will crack in a few months as soon as chloride ions come.
The flexible structure can almost neglect the thrust on the pipeline; The multilayered laminated fabric fibers are inherently not afraid of dilute acids; But also can simultaneously absorb axial, transverse and angular displacement. More importantly, its noise reduction effect is incomparable to metal parts.
In the desulfurization project of sintering machine in a steel mill, the original design used metal rectangular expansion joint. After half a year of operation, it was found that the weld seam frequently leaked. Later replaced withRectangular non-metallic expansion jointNever had any problems. This is not to say that the metal expansion joint is bad, it is used in the wrong place. Desulfurization scenario, non-metal is just needed.
IV. Behind price fluctuations: Who is at work with raw materials, processing cycle and project account period?
In the last two months, the price of fluororubber has increased by 20%, and so has PTFE. These are the main raw materials for the compensator skin. Aluminum silicate fiber cotton is stable, but the labor cost is high-the daily salary of a good skin master is almost catching up with that of an engineer.
The processing cycle is another variable. The standard cycle of custom parts is 30~45 days from blanking to factory. However, if you require the frame to be hot-dipped zinc for corrosion protection, or the skin requires imported fluororubber (such as DuPont's Viton), the cycle will be directly stretched to more than 60 days. In case of a project that rushes to the deadline, the manufacturer's expedited fee can eat 5% of the profit.
Then there is the accounting period. The industry practice is "3-3-3-1": 30% for advance payment, 30% before delivery, 30% after installation and commissioning, and 10% after expiration of warranty. However, many owners delay the payment until after acceptance, and even settle it with acceptance bills. When manufacturers' cash flow is tight, they will either increase prices or degrade quality.
So when you see a 20% difference between the two quotes, don't rush to pick the cheaper one. First ask clearly: Is there any difference in raw material batches? How long is the processing cycle? How to negotiate payment terms? These things are the essence of price fluctuations.
5. A few honest words for purchasing and engineers: how to pick, how to test and how to save
Something dry at last. What is the market of desulfurization non-metallic compensator? Quotes are dead, people are alive. If you master the following points, you will be able to step less on pitfalls:
How to pick?
First, confirm the working condition parameters: temperature, pressure, displacement amount, and medium composition. Don't just give a caliber and ask the manufacturer to quote. Second, manufacturers are required to provide running cases of the same type of projects, preferably in the past two years.
How to test?
When the goods arrive on site, don't just look at the appearance. Cut a small piece of skin sample and burn it with a lighter: real fluororubber flame retardant, self-extinguishing from fire; The counterfeit ones will drip oil and emit black smoke. Put the compensator flat and measure the difference of diagonal length. If the difference exceeds 3mm, the welding deformation exceeds the standard. Also, check the gap between the guide tube and the bellows, not less than 20mm, otherwise it will be damaged by friction after operation.
How to save?
Don't think about saving money on materials – all the money saved will turn into repair costs. The real way to save money is to choose a standard sizeNon-metallic expansion jointAvoid non-standard customization. In addition,Desulfurization flue gas baffle doorPackaging and purchasing with the compensator can often negotiate discounts. Finally, sign a warranty agreement with a reliable manufacturer: if it is damaged by people during the warranty period, it will be replaced for free. That's a lot more practical than the 5% of your hard-earned money you save.
What is the market of desulfurization non-metallic compensator? In the final analysis, the market is not good or bad in the total market volume, but in how professional you are. Think about this industry thoroughly, and you can deal with it calmly no matter the ups and downs.