What is a Sawdust dryer?

Sawdust dryer is suitable for drying powder/particle/shaving type wet sawdust materials. Sawdust materials are fed to dryer through screw conveyor. Under the fast conveying and scattering of hot air, moisture in wet materials is evaporate quickly and powder/particle final products are produced. Sawdust dryer mainly contains hot air furnace, feeding inlet, rotary drum dryr, pulse bag filter, material conveyor and induced draft fan. 

Application fields and value of sawdust dryer

Investing in a wood chip dryer transforms low-value or waste wood chips into valuable fuel or manufacturing feedstock. It drastically cuts disposal costs, generates revenue streams, improves material handling, and optimizes energy utilization.

Turning wood waste into treasure is the core function of a wood chip dryer. Here’s how it adds tangible value:

1. Creates Marketable Products: Dry wood chips are the essential raw material for:
   • Wood Pellets: A popular, high-density biofuel for heating.
   • Biomass Briquettes: Another form of densified fuel.
   • Particleboard/MDF: Requires precisely dried wood fibers/chips.
   • Wood-Plastic Composites (WPCs): Needs dry wood filler.
   • Direct Combustion Fuel: Dry chips burn much more efficiently and cleanly in industrial boilers.
2. Eliminates Disposal Costs: Instead of paying to landfill or manage wet wood waste, you process it into something valuable.
3. Improves Handling and Storage: Wet chips are sticky, prone to freezing, and can degrade or mold. Dry chips flow easily and store better (though self-heating risks in storage need management).
4. Increases Energy Efficiency: Whether used directly as fuel or converted to pellets, removing water significantly boosts the net energy yield per ton.
5. Meets Quality Specifications: Downstream processes demand specific moisture content. Drying ensures your material meets these specs, avoiding rejection or poor product quality.

Turning Waste Streams Profitable:

• Sawdust from sawmills
• Shavings from furniture factories
• Wood chips from forestry operations
• Recycled wood waste (properly cleaned)

What Factors Need Consideration When Choosing the Heat Source (Wood, Gas, Steam) for a Wood Chip Dryer?

Consider fuel availability and long-term cost, capital investment for the heating system, required temperature control precision, emissions regulations, operational complexity, and integration with existing plant utilities (like steam availability).

Selecting the right heat source is a critical decision impacting both the initial investment and ongoing operating costs of your wood chip drying system. Key factors include:

1. Fuel Availability and Cost:
   • Wood Waste/Biomass: If you generate sufficient wood waste on-site (or have a cheap local supply), using it as fuel can significantly reduce operating costs. Requires a suitable biomass burner/furnace.
   • Natural Gas/LPG: Clean burning, easy to control, often requires lower capital investment for the burner system. Fuel cost can be volatile and availability varies by location.
   • Fuel Oil: An alternative where gas isn’t available, but typically has higher emissions and fuel handling requirements.
   • Steam: If readily available from an existing plant boiler, steam provides excellent (indirect) heat control and eliminates combustion emissions at the dryer itself. Requires appropriate heat exchangers (like steam coils in an air heater or a steam tube rotary dryer). Cost depends on steam generation cost.
2. Capital Cost: Biomass combustion systems generally have a higher initial cost than gas burners. Utilizing existing steam may require modifications but avoids buying a new primary heat source.
3. Emissions Regulations: Burning biomass or oil produces more complex emissions (particulates, potentially SOx depending on fuel) requiring more robust flue gas treatment compared to natural gas. Steam (if generated cleanly) has no emissions at the dryer.
4. Temperature Control: Gas burners offer very precise and rapid temperature control. Biomass burners can be slightly less responsive. Indirect steam heating allows excellent, stable temperature control. The required precision depends on the drying application.
5. Operational Complexity: Biomass systems require fuel handling, storage, and ash removal. Gas systems are generally simpler to operate. Steam systems rely on boiler operation.
6. Safety Considerations: Direct firing with biomass requires careful management of sparks/embers potentially entering the dryer .

The best choice often depends on local economics and existing infrastructure. ZONEDING can help evaluate these factors and integrate the most suitable heat source for your specific wood chip drying needs.

What Main Equipment Components Make Up a Complete Wood Chip Drying System?

A wood chip dryer doesn’t operate in isolation. It needs several supporting machines to function correctly. Knowing all the parts helps in planning installation, space, and ensuring smooth operation from start to finish.

A complete system includes: Feed handling (hopper, screen, conveyor, feeder), the dryer unit itself, a heat source (burner/furnace/air heater), hot gas/air ducting, dust collection (cyclone/baghouse), exhaust fan, dried product discharge (cooling conveyor, storage), and a control system with safety interlocks.

A fully functional wood chip drying plant is an integrated system. While the dryer is central, several other pieces are essential:

1. Feed Preparation & Handling:
   • Receiving Area/Hopper: Where wet chips are initially delivered.
   • Screening (Optional but Recommended): Removes oversized pieces, rocks, metal (Insight #1) that could damage the dryer or pose a safety risk.
   • Conveying: Transports chips to the dryer feed point (belt conveyors, screw conveyors).
   • Metering Bin/Feeder: Ensures a consistent, controllable feed rate into the dryer – critical for stable operation (Insight #2).
2. Dryer Unit: The core machine (rotary drum or airflow system).
3. Heat Generation System:
   • Burner (Gas/Oil), Biomass Furnace, or Steam Air Heater.
   • Associated fuel handling, combustion air fans.
4. Ducting: Transports hot gas from the heat source to the dryer and carries moist exhaust gas away. Must handle temperature and potentially abrasion.
5. Dust Collection / Emission Control:
   • Cyclone(s): Primary dust removal.
   • Baghouse / Wet Scrubber: Final high-efficiency dust removal.
   • Dust Discharge: Rotary valves or screws to remove collected dust.
6. Exhaust System:
   • Induced Draft (ID) Fan: Pulls air/gas through the entire system. Often equipped with variable speed drive for flow control.
   • Stack: Releases cleaned exhaust gas to atmosphere.
7. Dried Product Discharge & Handling:
   • Outlet Breeching/Airlock: Removes dry product while minimizing air leakage.
   • Cooling Conveyor (Often Necessary): Hot dried wood chips can pose a fire risk if stored immediately. Cooling brings them to a safe handling temperature.
   • Storage Silo/Bin: For the final dried product.
8. Control System:
   • PLC & HMI: Centralized control and monitoring of temperature, feed rate, fan speeds, safety interlocks.
   • Instrumentation: Sensors for temperature, pressure, O2, CO, potentially moisture.
9. Safety Systems: Integrated components like spark detection/extinguishing, explosion vents, emergency stops .

Advantages and features of ZONEDING sawdust dryer

High Mechanical Level and Large Capacity

New type sawdust dryer adpopts automatic electrical centralized control and can run continuously. Materials scatter uniformly in dryer drum so that wet material fully contact with hot air and drying effect is good.

Simple Structure Easy Operation Long Service Life

Whole sawdust drying system holds reasonble design. Relying on smooth drying process, sawdust can be dried fast in dryer drum. By adopting heat-resistant steel plate and stainless steel texture, sawdust dryer is featured in long service life and low malfunction rate.

Low Energy Consumption and Good Final Product Quality

Sawdust dryer adopts multi pass structure which makes heat can be utilized layer by layer. Energy consumption is lower than traditional dryer and drying effect is superior. Customers can recover equipment investment cost quickly.

Flexible Configuration and Wide Application Range

Whole drying system can be configured with feeding, heat source, conveying, dust collecting, discharging and packing system based on customer’s requirements. It can be widely applied to fullfill different drying demands so that each customer can find suitable drying equipment.

Product Parameter

Spec./m (Dia.×Length)	Shell Cubage (m³)	Capacity (t/h)	Installation Obliquity(%)	Highest Inlet Air Temperature(℃)	Main Motor (kw)	Weight (t)
Φ1.2×8.0	9.0	1.9～2.4	3～5	700～800	7.5	9
Φ1.2×10	11.3	2.4～3.0	3～5	700～800	7.5	11
Φ1.5×12	21.2	4.5～5.7	3～5	700～800	15	18.5
Φ1.5×14	24.7	5.3～6.6	3～5	700～800	15	19.7
Φ1.5×15	26.5	5.7～7.1	3～5	700～800	15	20.5
Φ1.8×12	30.5	6.5～8.1	3～5	700～800	18.5	21.5
Φ1.8×14	35.6	7.6～9.5	3～5	700～800	18.5	23
Φ2.2×12	45.6	9.7～12.2	3～5	700～800	22	33.5
Φ2.2×14	53.2	11.4～14.2	3～5	700～800	22	36
Φ2.2×16	60.8	13.0～16.2	3～5	700～800	22	38
Φ2.4×14	63.3	13.5～16.9	3～5	700～800	37	45
Φ2.4×18	81.4	17.4～21.7	3～5	700～800	37	49
Φ2.4×20	90.4	19.3～24.1	3～5	700～800	45	54
Φ2.4×22	99.5	21.2～26.5	3～5	700～800	45	58
Φ2.6×24	127.4	27.2～34.0	3～5	700～800	55	73
Φ3.0×20	141.3	30.1～37.7	3～5	700～800	75	85
Φ3.0×25	176.6	37.7～47.1	3～5	700～800	75	95
Φ3.2×25	201	42.9～53.6	3～5	700～800	90	110
Φ3.6×28	285	60.8～76.0	3～5	700～800	160	135

Customer Cases