CETAL engineers and expert define the watt density through an heat exchange software allowing to take into account all parameters.
CETAL software can effect detailed heat exchange calculations, the key outputs are:
- Wire temperature
- Tubular sheat tube temperature
- Watt density
- Pressure loss
- Heat exchange coefficient
For basic design, please find below some references sorted by fluids.
- Water
- Stagnant water, max load 8 – 12 W/cm², material: copper, 321, 316L
- Circulating water, max load 10 – 16 W/cm², material: copper, 316L, inc 800, inc 825
- Boric water, max load 8 W/cm², material: 316L
- Boiler water, max load 8 – 16W/cm², material: 316L, inc 800, inc 825
- Chlorated water, max load 6 W/cm², material: inc 825
- Sea water, max load 3,5 – 6 W/cm², material: inc 825, inc 600
- Demineralized water / deionized / distilled / softened, max load 4 – 6 W/cm², material: 316L, inc 800, inc 825
- Domestic hot water, max load 4 – 8 W/cm², material: copper, 316L, inc 825
- Caustic water (2%, 10%, <30%, 70%), max load 2,3 – 7 W/cm², material: 316L, inc 825, inc 600
- Oil
- Fuel oil pre-heating, light fuel oil, C fuel oil, max load 1 – 2 W/cm², material: 321, 316L
- Heavy fuel, max load 0,5 – 3,5 W/cm² acc to grade, material: 316L
- Gasoline, kerosene, max load 3,0 – 3,5 W/cm², material: 316L
- Machine oil SAE 10, 30, 40 & 50, max load 2,0 – 3,5 W/cm², material: 316L
- Mineral oil , max load 0,5 – 3,5 W/cm² acc to temp, material: 321, 316L
- Lube oil, max load 2,3 W/cm², material: 321, 316L
- Acid & corrosive fluid
- Acetic acid, max load 6W/cm², material: 316L, inc 825
- Boric acid, max load 6W/cm², material: inc 825
- Chloric, hydrofluoric, nitric, sulphuric acide, max load 1,5W/cm², material: teflon coat
- Boric acide, max load 6W/cm², material: inc 825
- Alkaline bath, max load 6W/cm², material: 321 (no corrosive compound), 316L
- Phosphate bath, max load 4W/cm², material: 316L, inc 825
- Glycol
- Ethylene glycol, propylene glycol, 4 to 8 W/cm² acc. to concentration, material: 321, 316L
- Others
- Asphalt, tar, and other heavy or highly viscous compounds, max load 0,5 – 1,5W/cm², material: 316L
- Milk, max load 0,3W/cm², material: 316L
- Gas
- Air, max load 0,1 – 8W/cm² acc. to sheath temp, material: 321
- Circulating air, max load 0,1 – 8 W/cm² acc. to sheath temp, material: 309
- Natural gas, max load 0,1 – 8 W/cm² acc. to sheath temp, material: 321, 316L
- Argon, nitrogen, W/cm² acc. to sheath temp, material: 321, 316L, inc 825, inc 600
- Propan, Butane, W/cm² acc. to sheath temp, material: 321, 316L
- Oxygen, Hydrogen, W/cm² acc. to sheath temp, material: 316L
- Solids
- Aluminium, brass, bronze cast in, max load 4 – 15W/cm², material: 309
- Copper-nickel cast in, max load 5 – 10W/cm², material: 309
- Oxychloration, max load 3 W/cm², material: inc 800, inc 825
- Calcination, max load 3 W/cm², material: inc 800, inc 825