FRP storage tank is a kind of FRP products. It is a new composite material made by winding with microcomputer controlled machine with glass fiber as reinforcement and resin as adhesive. FRP storage tank has the characteristics of corrosion resistance, high strength, light weight and long service life. Because it also has the characteristics of flexible design and strong manufacturability, it can be flexibly designed and applied in different industries, such as chemical industry, environmental protection, food, pharmaceutical and other industries. It is gradually replacing most market fields of carbon steel and stainless steel. FRP tanks can be divided into vertical tanks, horizontal tanks, FRP tanks, chemical tanks, anti-corrosion tanks, reagent storage tanks, food tanks, transportation tanks, storage tanks, glue tanks, chemical tanks, pressure tanks, soy sauce tanks, etc.
Use site of FRP storage tank
In order to ensure the strength performance and corrosion resistance of FRP storage tank, the continuous filament winding integral forming method and the layered structure of inner lining layer (inner surface layer and sub inner layer) + structural layer + outer protective layer are adopted to make FRP storage tank have better corrosion resistance and strength bearing capacity.
1、 Paving structure of FRP storage tank:
(1) Inner surface layer: reinforced by lining resin and surface felt, with resin content of more than 95%, good air tightness and very smooth. This layer mainly provides anti-corrosion
Anti leakage and other functions. Its thickness is about 0.5mm.
(2) Secondary inner layer: it is composed of lining resin and chopped FRP fiber. The resin content is more than 70%. The main function of this layer is to protect the inner surface and improve the inner surface
The lining has the ability to resist internal pressure failure and prevent crack propagation. The secondary inner layer and inner surface layer are collectively referred to as the inner layer, with a total thickness of more than 4mm.
3) Structural layer: the resin of the structural layer is infiltrated by glass fiber cloth and cured. The resin content of this layer is usually about 50%. The function is to bear compressive stress
Tensile stress and various external loads, and the wall thickness shall be determined through reasonable and scientific optimization calculation according to the stress condition of the storage tank. Filament wound products have
High strength and stiffness, good mechanical properties, high and stable product quality.
(4) Outer protective layer: because this layer is in the atmosphere, it is vulnerable to light, oxygen and climate aging. In addition, this layer is vulnerable to the corrosion of volatile media in the air,
The resin content is 100%, and UV-9 ultraviolet absorber is added to the resin to prevent photo oxygen aging. The thickness of this layer is about 1mm.
Use of FRP storage tank
2、 Performance advantages of FRP storage tank:
1. High brightness - the inner wall of FRP storage tank is smooth without burr. It is easy to thread the cable and will not scratch the cable.
2. Flame retardant, heat and frost resistance - FRP cable duct can be used at - 50 ℃ - 130 ℃ for a long time without deformation.
3. The construction equipment is convenient - the weight of FRP storage tank only needs about 1 / 4 of steel pipe and about 1 / 10 of concrete pipe. The transportation and laying methods are simple and convenient.
4. Corrosion resistance - FRP tanks are specially designed to resist the corrosion of many chemical fluids such as acid, alkali, salt, untreated sewage, corrosive soil and groundwater.
5. Product features: FRP storage tank is a kind of light, high-strength and corrosion-resistant non-metallic pipeline. It is made of resin as matrix and glass fiber as reinforcement through special process.
3、 Production process flow of FRP storage tank
1. Preparations.
(1) Carefully read the design documents, pay attention to the selection of raw materials, the size of each part, the selection of molds, ply design and other key matters, and be aware of them.
(2) Equipment commissioning. First, carefully check whether the equipment operation and working parts are normal, especially carefully check whether the resin curing agent two-component pump is blocked and whether the ratio meets the design requirements; Ensure the operation stability and working accuracy of lining, winding, trimming, demoulding and other equipment;
(3) Clean the mold. The surface of the mould shall be free of pits, dust, sundries and other attachments. The surface of the mould shall be smooth, and any problems shall be repaired and maintained in time;
(4) Wrapped with polyester film. In order to facilitate demoulding, a layer of polyester film shall be coated on the surface of the die, with the overlapping width of 1 ~ 2cm and the thickness of 40um. The film shall be free from damage and wrinkles, and both sides shall be smooth and clean. The quality of film products meets the requirements of GB 13950-1992.
2. The inner lining of the cylinder is formed. According to the structure, the lining is divided into inner lining layer and transition layer, which mainly plays the role of anti-corrosion and anti-seepage.
(1) Lining resin preparation. The resin formulation system made according to the working environment and temperature conditions at that time shall be mixed with the lining resin, and the batching amount shall be reasonably controlled according to the manufacturing progress. When the site situation changes, the manufacturing department shall timely adjust the formula and prepare the required resin according to the new formula;
(2) The lining layer shall be made according to the laying steps required by the design. The lining is made of steel mold and sprayed by imported Venus spray gun. The resin content of the lining is high and has good anti-corrosion and anti-seepage effect. The resin content of the lining layer is 80% - 90% and that of the transition layer is 68% - 78%.
(3) Process inspection. After each layer is paved according to the design requirements, the operators are required to conduct preliminary quality inspection: whether the lining reaches the design thickness, whether there is glue deficiency and glue hanging in some parts, and whether there are white spots and bubbles. If the above conditions occur, treatment measures shall be taken in time;
(4) The lining is deeply cured and demoulded.
3. Upper and lower head forming reinforcement. The head is divided into inner lining layer and structural layer according to the structure.
(1) The forming process and raw materials of the head inner lining are the same as those of the barrel inner lining. It is spray formed by spray gun with high resin content. The head lining layer is laid and deeply solidified.
(2) The structural layer of the head is laid, and the spray gun sprays the spray yarn and the glass cloth alternately. During the laying of each single layer of glass cloth, a reasonable tension shall be applied, an appropriate amount of overlap shall be overlapped with each other, and the combined roller shall be used to roll repeatedly to drive out bubbles, so as to ensure the complete penetration of the fiber. Each reinforcing material layer is required to meet the design resin content requirements.
(3) Process inspection, deep curing and demoulding.
FRP storage tank
4、 Methods of improving the service life of FRP storage tank
1、 The FRP tank should not be moved frequently during use: This is because if the FRP tank is moved frequently after being used for a period of time, it will cause the axial stress damage of the structural layer of the FRP tank, reduce the strength of the tank and affect the service life of the FRP tank.
2、 During the use of FRP storage tanks, the vent hole shall be kept open or the tank interior shall be kept under normal pressure: This is because many quality accidents of storage tanks are mostly due to the tank's pumping process. Due to the blockage of the vent hole, negative pressure is generated in the FRP tank, resulting in internal absorption damage. Therefore, keeping the vent hole open or the tank interior under normal pressure is very important to the service life of FRP tanks.
3、 FRP storage tanks should be effectively covered: This is because long-term ultraviolet radiation will degrade the resin and reduce the strength. At the same time, due to the erosion of wind, rain and frost on the surface of FRP tank and the degradation of resin, the glass fiber in FRP tank will be eroded and dissolved under the action of microcrack and interface, which will accelerate the aging process and reduce the strength. Therefore, FRP tank should be effectively covered to prolong the service life of FRP tank.
