what is a Sulfurization bed drying equipment?

what is a Sulfurization bed drying equipment?

Sulfurization bed drying equipment (fluidized bed dryer)
Commonly known as boiling bed drying equipment, it belongs to the continuous/intermittent drying equipment for granular powder, and is widely used in the organic fertilizer, compound fertilizer, chemical, and feed industries

Working principle of sulfurization bed drying equipment

After filtering and heating, the hot air passes through the porous gas distribution plate from the bottom and blows upwards; When the airflow velocity reaches the minimum fluidization velocity, solid particles on the bed are suspended by the airflow, and the particles roll and boil with each other (fluidization, where solids flow like liquids); Hot air and particles come into full contact, quickly completing heat and mass transfer, and evaporating material moisture; The exhaust gas is discharged from the upper part and undergoes dust removal; Dry materials are discharged from the discharge end.

Vibration fluidized bed with additional vibration motor: relying on vibration to assist the material to move forward, reducing the required air pressure for fluidization, especially suitable for particles with slight viscosity and uneven particle size

The main components of the sulfurization bed drying equipment are:

1. Air handling system: filter, hot air heater (steam/thermal oil/gas hot air)
2. Host bed body: gas distribution plate (core component), fluidization chamber, vibration motor (vibration type)
3. Discharge mechanism (adjustable weir plate to control the thickness and residence time of the material layer)
4. Exhaust dust removal system: cyclone separator+bag filter (for recovering fine powder)
5. Induced draft fan

The main categories of sulfurization bed drying equipment are:

1. Intermittent vertical fluidized bed (GFG high-efficiency boiling dryer): batch production, pharmaceutical, small batch chemical; Cannot continuously feed and discharge materials
2. Horizontal ordinary fluidized bed (XF) continuous type: long slot bed, material flows forward by gravity; Suitable for particles with good fluidity; Easy to cause gully flow and dead bed; Less used in the fertilizer industry
3. Horizontal vibrating fluidized bed ZLG (most commonly used in the fertilizer industry): vibration assisted conveying; Continuous feeding and discharging; Can be divided into drying and cooling zones; After drying, the material is directly cooled and discharged, eliminating the need for a separate cooling machine; Preferred models for compound fertilizers, organic fertilizer granules, and mineral salts

Advantages of vulcanization bed drying equipment:

1. High heat and mass transfer efficiency, fast drying speed, uniform temperature inside the bed, and less prone to local overheating
2. The vibrating fluidized bed can integrate drying and cooling, shortening the process flow
3. Adjustable dwell time; Can adapt to different feed moisture contents; Continuity is suitable for large-scale production lines (supporting organic fertilizer compound fertilizer production lines)
4. There are no heavy rotating rolling parts inside the bed, and the particle crushing rate is lower than that of the drum dryer
5. High thermal efficiency, generally 55-75%

Typical applications of vulcanizing bed drying equipment (key focus of fertilizer industry):

-Compound fertilizer granules, extruded granular fertilizer; Drying and cooling of organic fertilizer granules after granulation (ZLG vibrating fluidized bed is very common and often placed after or instead of drum cooling)
-Feed pellets, salts, minerals, food pellets
Attention: High moisture wet fermented organic fertilizer (without pre drying) should not be directly fed into the fluidized bed, as it is prone to sticking to the bed board; Generally, it is pre dried by a drum before entering a fluidized bed for precision drying and cooling

Main selection reference parameters for sulfurization bed drying equipment (ZLG vibrating fluidized bed)

-Fluidization area: 2-20 square meters (selected based on evaporation capacity)
-Inlet air temperature: 60-140 ℃ (fertilizer generally 80-120 ℃)
-Material retention time: adjustable from 3-15 minutes; Amplitude 1-4mm; Vibration motor power 2 × (1.5-7.5) kw
-Evaporation water volume: tens of kg/h to over 2000kg/h
-Material: ordinary carbon steel; Contact material: 304 stainless steel (recommended for corrosive fertilizers)

Common process route examples: organic fertilizer → disc granulation → drum pre drying → ZLG vibrating fluidized bed precision drying+cooling → screening