Chemical Pretreatment Tanks Galvanizing Equipment

Hot-dip galvanizing pretreatment equipment

1. Selection of acid and alkali cleaning tank materials

The pre-treatment process tanks in the hot-dip galvanizing workshop include degreasing tanks, pickling tanks, solvent tanks, cleaning tanks for water washing after degreasing and pickling, and water cooling, passivation, and water washing tanks for workpieces after hot-dip galvanizing. Degreasing liquid, acid liquid and the water after rinsing degreasing or pickling workpieces are all corrosive, so these tanks and related grounds, pipes, and drainage facilities need to use various building anti-corrosion materials and coatings. There are many kinds of building anti-corrosion materials and coatings, and various anti-corrosion materials have different corrosion resistance to acids, alkalis, salts and other media. Cement materials have good alkali resistance, but poor acid resistance; asphalt materials have good resistance to dilute acids and alkalis, but are not resistant to concentrated acids, concentrated alkalis, and organic solvents; water glass materials have excellent Acid resistance, but not alkali resistance; Epoxy materials have good comprehensive properties of acid, alkali and salt resistance, but not strong oxidizing acid resistance. From the perspective of the law of thermodynamics, a material is relatively stable under certain environmental effects, but it will be damaged and deteriorated under other environmental effects. Therefore, when selecting materials, efforts should be made to maximize strengths and avoid weaknesses, and make the best use of everything. The structural materials of the surface pretreatment tank include granite, marble, PP plastic and glass steel. Granite and marble as the surface treatment tank are both resistant to acid and alkali corrosion and have high strength, and are not afraid of collision; PP plastic as the surface treatment tank has good acid and alkali resistance, but it is necessary to prevent the workpiece from colliding with it due to its low strength; the above two This material is more expensive. In order to save investment, these treatment tanks can be coated with glass fiber reinforced plastic inside and outside the cement concrete frame. Before coating the FRP coating, a layer of epoxy resin should be applied to the cement concrete tank. Its acid resistance, alkali resistance and heat resistance fully meet the needs of production. Where conditions permit, granite, marble, and PPE boards can be used as the lining of these treatment tanks. The engineering cost is relatively high, and the service life can generally reach 8 to 10 years.

2. Manufacture of pretreatment tank

2.1. Manufacture of degreasing (alkaline cleaning) tanks

For all alkaline degreasing liquids or degreasing liquids based on surfactants, it is more suitable to make degreasing tanks with low carbon steel plates. The inner wall of the tank can be protected by a general high temperature and alkali corrosion resistant coating, while the outer wall needs to be protected by an anti-rust layer and kept dry to reduce surface corrosion. Maintenance is rarely required and is very convenient. The degreasing tank can use a heat exchanger made of low carbon steel (heating medium can be hot water, steam and gas) or an electric heater to heat the degreasing liquid.

2.2. Pickling tanks, solution tanks and cleaning tanks

Pickling tanks, solvent tanks and cleaning tanks should be resistant to acid or ammonium chloride corrosion. These tanks are generally made of steel or concrete as a solid basic tank, and then a corrosion-resistant material layer is laid on the surface of the base body on the inner wall of the tank. The surface layer of the base material should be treated in advance, and whether the treatment is proper will directly affect the quality of the anti-corrosion project.

The tank body is constructed with cement mortar concrete, which is required to be strong and firm, and there should be no sanding, shelling, cracks, pitting, etc. Surface flatness and surface slope shall comply with the design requirements, as well as the requirements of construction and acceptance specifications for building anti-corrosion engineering. The yin and yang corners should be arc-shaped or inclined.

Our company mainly business scope is as follows:   

1) The design, manufacture, installation, commissioning and training of the hot dip galvanizing lines, redesign and improve of the old galvanizing plants.   

1. Jobbing galvanizing line for construction parts: such as steel tower , tube tower parts, high rails and lighting poles , etc. 

2. Galvanizing lines for steel tubes:suitable for 1/2"-8" steel tube.

3. Galvanizing lines for small parts:suitable for bolts, nuts and other small parts. 

2) The related chemical preprocessing of products and alloy   

Our main products are : chemical pretreatment tanks, galvanizing furnace, zinc kettle, utilisation of fuel gas from the fuel furnace, drying pit.   

If you have any questions, please contact our engineers for consultation, online.