Alfa Laval and SGL Carbon, Germany, worked together to develop DIABON® plate heat exchangers. This collaborative effort combines Alfa Laval’s plate heat exchanger know-how with SGL Carbon’s expertise in graphite process equipment. The resulting product combines the high-efficiency heat transfer benefits of conventional plate heat exchangers with the exceptional corrosion resistance of graphite material.
DIABON® plate heat exchangers are therefore ideal for handling highly corrosive fluids such as:
- Hydrochloric acid and gas in all concentrations
- Sulphuric acid up to 90%
- Hydrofluoric acid up to 60%
- All concentrations of phosphoric acid
- Pickling acids in surface treatment plants
- Electrolytes used in the mining industry
- mixed acids
- Chlorinated hydrocarbons
- Catalysts such as aluminium chloride.
Applications
Heaters, coolers, interchangers, condensers and evaporators
for corrosive media, especially in the treatment of:
- Hydrochloric acid (HCI)
- Sulfuric acid (H2SO4)
- Hydrofluoric acid (HF)
- Mixed acid (HNO3/HF)
- Phosphoric acid (H3PO4/P2O5)
- Other organic and inorganic media
Standard design
The graphite plate heat exchanger consists of a pack of corrugated graphite plates with portholes for the passage of the two fluids between which heat transfer will take place. The plate pack is assembled between a carbon steel fixed frame plate and movable pressure plate and compressed by tightening bolts. The difference in coefficients of expansion of carbon steel and graphite is compensated for by means of helical springs. The plates are fitted with a film type PTFE gasket of 0,2 mm thickness after tightening, which seals the interplate channel and directs the fluids into alternate channels. The number of plates is determined by the flow rate, pressure drop and temperature program. The plate corrugations promote fluid turbulence and minimize fouling. The frame plate and pressure plates are suspended from an upper carrying bar and located by a lower guiding bar, both of which are fixed to a support column. Connections are located in the frame plate or, if either or both fluids make more than a single pass within the unit, in the frame and pressure plates. The frame and pressure plates are protected from the corrosive media by means of a PTFE lining.
Typical capacities
Max flow rate of 250 m3/h, depending on media, permitted pressure drop and temperature program.
Plate types: S1, M10-G, S10, S15.
Frame types: One standard frame available that can be modified to higher design pressures.
Working principle
Channels are formed between the plates and the corner ports are arranged so that the two media flow through alternate channels. The heat is transferred through the plate between the channels, and complete counter current flow is created for the highest possible efficiency. The corrugation of the plates provides the passage between the plates, supports each plate against the adjacent one and enhances the turbulence, resulting in efficient heat transfer.
Standard materials
Plates: F100, NS1/NS2
