high temperature fluidized bed drying and calcining technologies

Solutions for Drying & Calcining

High Temp Fluidized Bed Dryer / Calciner

Delta Drying Technologies LtdAdd: Suite 219, Block B ， Qilu Software Park, No. 1 Shunhua Rd, Jinan, ChinaEmail: [email protected]; [email protected] Website ： www:coaldryingtech.comTel ： 0086-13953108165; 001-610-829-9317

High Temperature Fluidized Bed Dryer /

Calciner

• Rotary dryer is often considered as (1), robust, and valued for their reliability; (2) high throughput capacity; (3) ability to accept variability in feedstock;

• While fluidized bed dryer is considered as (1) having a smaller footprint than rotary dryer; (2) only for small processing facilities; (3) lower ability to accept variance in feedstock.

Actually, some of the above statements are wrong, and even total opposite.

• (1) Rotary dryers are robust and reliable. It is true that rotary dryers can be operated over 10 or 20 years and fluidized bed dryers are shorter. That was caused due to design and fabrication: fluidzed bed dryer is stationary with minimum moving parts and therefore it can be designed and fabricated with lower strength; rotary dryer is rotating and therefore it has to be designed and fabricated with higher strength. For fluidized bed dryer for coal drying, they have been in operation since 1970 and they are still in service now;

• (2) Throughout. It is total opposite. For lignite coal drying with 40% moisture, the maximum throughout with rotary dryer is less than 100t/h; while it can up to 1000 t/h or even higher for fluidized bed dryer;

• (3) Ability to accept variability in feedstock. It is correct only to some degree. Fluidization requires minimum velocity and maximum velocity and rotary dryer does have such a requirement on velocity. The maximum velocity is 5 to 10 times higher than minimum velocity and there is still adjustment range for selected material.

High Temperature Fluidized Bed Dryer / Calciner

High temperature fluidized bed dryer

The maximum inlet temperature for conventional fluidized bed dryer/ calciner is around 650 C due to limitation caused by air distribution plate design, few of them can be increased to 750C after modification. The maximum inlet temperature for rotary dryer / calciner can be 1000 C, even 1050C. The actual inlet temperature is about 900 C to 950 C due to leaking from kiln hoods.

The maximum inlet temperature for new type fluidized bed dryer / calciner could be up to 1100 C for explosive material drying and 1400 C for non-explosive material drying with new design of air distribution plate. High inlet temperature makes it possible to integrate drying, heating and calcining, which can shorten process, reduce equipment dimensions and capital cost.

Modifications to air distribution and discharge device makes sure that clumping can be eliminated during operation.


Comparison between High Temperature Fluidized Bed Dryer and Rotary Dryer (For frac sand drying )

Rotary dryer：Wet sand ： 210t/h;Inlet moisture: 6%;Final moisture: 0.5%;Discharged temp: 70C;Air flow: 43000m3/h;Diameter of rotary dryer: 2.75m;Length of dryer: 16 m;Weight of dryer: 75 t; High temp fluidized bed dryer (same throughout): Air flow: 33000m3/h;Area of fluidized bed: 4m2;Weight of dryer: 35 t;

High temp fluidized bed:(1)Lower capital cost, 65% or so as rotary dryer;(2)Lower power consumption due to lower air flow;(3)Lower energy consumption due to higher inlet temp;


Comparison between High Temperature Fluidized Bed Dryer and Fluidized Bed Dryer with Immersed Steam Heat Exchanger (For salt drying )

Fluidized Bed Dryer with Immersed Steam Heat Exchanger:Wet salt: 21t/h;Inlet moisture: 3%;Final Moisture: 0.15%;Salt discharged temp from dryer: 75C;Air flow: 7100m3/h;Bed Area: 1.5 m2;Steam consumption: 840000 kcal/h;

High Temp Fluidized Bed Dryer (same throughout): Air flow: 2100m3/h;Bed area: 0.5 m2Energy consumption: 600000 kcal/h;

High temp fluidized bed:(1)Lower capital cost, 50% or so as Fluidized Bed Dryer with Immersed Steam Heat Exchanger;(2)Lower power consumption due to lower air flow;(3)Lower energy consumption due to higher inlet temp;


Comparison between High Temperature Fluidized Bed Dryer and Steam Rotary Dryer (For coking coal drying )

Steam Rotary Dryer:Wet coal: 300t/h;Inlet moisture: 10.5%;Final moisture: 6.5%;Diameter of rotary dryer: 4.2 m;Length of rotary dryer: 21 m;Heat exchanger area: 2063 m2;Weight of dryer: 275 ton;Steam pressure: 1.5MPa;Steam temp: 250 C;Air flow: 71000m3/h;

High temp fluidized bed dryer (same throughout): Air flow: 70000m3/h;Bed area of dryer: 5 m2;Weight of dryer: 60 ton;

High temp fluidized bed:(1)Lower capital cost for process equipment, 50% or less as Steam Rotary Dryer;(2)Lower energy consumption due to higher inlet temp;


Comparison between High Temperature Fluidized Bed Dryer / Calciner and Rotary Dryer / Calciner (For Oxide Nickel drying / calcining in RKEF process )

High temp fluidized bed dryer / calciner: Wet oxide nickel: 160 t/h;Inlet moisture: 30%;Final moisture: 0%;Discharged temp from dryer / calciner: 900 C;Bed area: 25 m2;Weight of dryer / calciner: 600 ton;Air flow: 200000 m3/h;Capital cost for process equipment: $15 million;


Application

High temp fluidized bed drying technology can be used for the drying, heating and calcining of non-heat-sensitive materials in the form of (or can be converted to by mixing process ) lump, grains and powder; :•Building material: sands, quartz sand, frac sand, etc;• Fertilizers: KCl, KSO4, etc; •Inorganic salts: Compounds of sodium, calcium, magnesium, manganese, nickel, lithium, etc;• Non-Metallic and Metallic Ore: Cu concentration, kaolin/ clays, etc;• Wastes: Municipal and industrial sludge, industrial solid wastes, etc;

Activated CarbonAggregateAluminum HydroxideAmmonium SulfateBariteBauxiteBentoniteBlast Furnace SlagBoraxBoric AcidCalcium CarbonateCalcium SulfateCarbon BlackCement KlinkerChrome SandClay

CoalCopper ConcentrateCopper OxideCryoliteDiatomaceous EarthDolomiteIlmeniteIron OreLead ConcentrateLimestoneMagnesiteMagnesium SulfateManganeseMelamine ResinMicaMolybdenum SulfideMolybdic Oxide

Nickel ConcentratePerlitePhosphatePotashPolyphosphate SaltsPotassium NitratePotassium SulfateQuartzRutileSaltSandSewage SludgeSilica SandSoda AshSodium BicarbonateSodium ChlorateSodium Dichomate

Sodium PhosphateSodium SulfateSodium SulfiteSpodumeneTinTitanium DioxideTronaUraniumVanadiumZinc Concentrate

high temperature fluidized bed drying and calcining technologies

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