The ambient temperature of flue, gas scrubber and industrial coating system can reach Therefore, it is necessary to select materials with superior heat resistance and strong acid resistance to cope with the harsh chemical and high temperature environment.
Derakane epoxy vinyl ester resin provides excellent corrosion resistance against harsh chemical environments and has been the most reliable technology in this field since its inception 65 years ago. Derakane resin has established the industry standard for corrosion resistance of liquid storage and transportation equipment for chlor alkali, bleach and hydrochloric acid industries.
ashland Derakane scientists focus on the development of innovative technologies to create high-temperature performance unmatched by previous mainstream resins.
What is the performance comparison of various construction materials under severe extreme conditions ?
Rubber lining
It usually has corrosion resistance and heat shock resistance, but high temperature will lead to rubber degradation.
Stainless steel and high nickel alloy
Although they also have corrosion resistance and heat shock resistance, they can not resist high temperature and moisture inorganic acid for a long time, thus shortening the expected life of the equipment. In fact, high nickel alloys are often severely corroded after one year of service.
Acid resistant brick lining
It is a traditional choice because of its excellent acid resistance, heat resistance and heat shock resistance. However, the problem is that it is difficult to choose a suitable mortar system for use, because the mortar system is easily affected by the chemical environment, which will lead to the brick falling off the vessel wall, and the maintenance of the brick lining will also cause long-term downtime.
Derakane epoxy Vinyl ester resin
In order to meet the application requirements of higher temperature, Ashland technicians changed the polymer skeleton, adjusted the proportion of comonomer in the resin, and opened the FRP is a new application field in high temperature environment.
Derakane 470ht phenolic epoxy vinyl ester resin It can change the glass transition temperature（ TG) increased to above 190-220 ℃. The upgrading of polymer structure can also improve the acid resistance of the resin, which can effectively cope with the corrosive environment commonly seen in the inlet of scrubber. In addition, derakane 470ht inherited Vinyl resin The traditional advantage of this product is its excellent toughness, which makes it easy to resist the thermal shock commonly seen in the quench treatment of scrubbers.
Although there are a large number of resins with extremely high glass transition temperature on the market. However, although the glass transition temperature is high, these resins are lack of thermal stability and will decompose gradually during use. For design engineers, the glass transition temperature and thermal deformation temperature of the resin should be considered before selecting high temperature resistant resin（ HDT) is a wise move.
The thermal aging study of derakane 470ht showed that, except for color change, the effect of environment above 180 ℃ on the mechanical properties of the product was negligible, even after 12 months
Cross section of derakane 470ht specimen (at 200 ℃ for one year)
Parts applied to high temperature environment Example of derakane product:
1. Chimney lining and piping system of Turow / power plant, Poland
One of the two devices is already in the It operates at 160 ℃ for two years. The old chimney lining is made of borosilicate brick and needs to be replaced. All FGD units consist of a chimney lining with a diameter of 5.3m and a height of 120m, and a piping system with the same diameter and a total length of 330m. The project finally chose derakane 470ht as the product has chemical resistance to wet flue gas and can adapt to temperature of 160 ℃ and above.
2. Heidelberg / municipal waste incinerator, Germany
The original quench treatment device of the scrubber is composed of Hastelloy ™ C. After only 6000 hours of operation of the quench treatment unit, holes began to appear on the vessel wall. After stopping the device, it was found that the thickness of the vessel wall was reduced from 5 mm to 2 mm, which was difficult to provide the structural strength and hardness required for the actual safe bearing capacity. Finally, the FRP solution based on derakane 470ht replaced the damaged Hastelloy structure. After running at 220 ℃ for 30 months, the structure of the quench treatment device is intact and there is no hole.
3. Arkmar / municipal waste incinerator, the Netherlands
In this example, the design temperature of the quench treatment device of the incinerator is The operating temperature is usually between 200 ℃ and 220 ℃. The derakane 470ht, which contains a large number of nozzles and fittings, was first commissioned in 1995. The insulation layer is composed of carbon / graphite fiber reinforced plastic and an air gap. This new design shows excellent performance.
4. Talagona / industrial waste incinerator, Spain
In this example, the design temperature of the incinerator chimney is 150-200 ℃, bypass temperature is 220 ℃, heating and cooling cycle lead to drastic temperature changes. The diameter of chimney lining is 1.6m and the height is more than 60m. The new chimney lining is made of derakane 470ht, which has been in use since 1998 due to its outstanding performance. A recent inspection found that the lining was still in good condition after 16 years of use.
5. High temperature FRP flue of Guiyang Huaxi waste incineration power plant
As one of the main facilities of the waste incineration power plant, the exhaust flue should not only realize the normal discharge of the incineration flue gas, ensure the normal operation of the waste incineration power generation equipment, but also bear the serious corrosion of the incineration flue gas. Working temperature of the flue 140 – 160 ℃, and the extreme temperature is 220 ℃, which is made of Ashland derakane 470ht-400 vinyl ester resin.
conclusion
Derakane is a kind of epoxy resin with better corrosion resistance. The derakane 470ht exhibited excellent thermal stability both in laboratory and in practical use. This product can effectively deal with the temperature and corrosion environment of scrubber inlet and chimney lining.
