How to choose a star-shaped discharger

1. Select the model based on processing capacity (the most crucial factor)

Calculation requirements: Based on the process hourly flow rate Q (m³/h or t/h), select the rated flow rate = (1.2–1.5) × Q, to avoid blockage.

Model and speed: Commonly used YJD series (such as YJD2/4/6/16, each rotation 2/4/6/16L); speed ≤ 30rpm, abrasive materials ≤ 20rpm, light materials can be slightly higher.

Flow formula: Q = K · V · ρ · n (K = 0.6–0.8 filling coefficient, higher powder and particle materials; V = rotor effective volume; ρ = bulk density; n = speed).

2. Determine the structure and material based on material properties

Temperature: Normal temperature (< 200℃) select standard type; 200–500℃ select high-temperature resistant type (insulation + high-temperature sealing).

Particle size / fluidity:

Fine powder materials (fly ash, cement): standard straight blade, gap 0.5–1mm.

Large particles (> 5mm): rotor cavity ≥ particle size 2–3 times, anti-clogging structure.

Viscous / Moist (clay, wet powder): with scraping plate, large gap, anti-sticking coating.

Fiber materials (wood chips, fiber powder): open rotor, elastic blade, anti-tangling.

Corrosion / wear:

Common dust: carbon steel (Q235).

Food / weak acid: 304 stainless steel.

Strong acid / chloride ions: 316L / Hastelloy alloy, PTFE seal.

High wear (mineral powder, slag): carbon steel + wear-resistant overlay / liner.

3. Select the sealing grade based on system pressure

Normal pressure (±0kPa): standard packing seal, ordinary gap.

Negative pressure dust removal (-5~-30kPa): enhanced seal (double packing, gas seal), prevent air leakage and backflow.

Positive pressure (≥0.1MPa): pressure-resistant thickened shell, high-performance seal, optional double-stage valve.

4. Interface and installation matching

Flange type: A type (square mouth, good sealing, commonly used); B type (round mouth, easy installation), select according to the diameter of the upper and lower equipment.

Installation space: measurement diameter, height, length, avoid size mismatch.

5. Drive and safety configuration

Motor: normal environment select Y series; variable frequency (speed adaptation to variable conditions); flammable and explosive select explosion-proof motor (Exd II BT4).

Power: small diameter (≤ YJD10) 0.55–1.1kW; medium diameter 1.5–3kW; large diameter ≥ 4kW.

6. Overview of selection steps

Clarify processing capacity, material properties, system pressure, interface size, installation space.

Calculate theoretical volume, select model based on 1.2–1.5 times, determine speed and filling coefficient.

Select sealing grade based on pressure, select material and rotor type based on materials.

Match drive (ordinary / variable frequency / explosion-proof), confirm installation size.

7. Common model recommendations (reference)

YJD-A-6: square mouth, 6L / rotation, 0.75kW, suitable for 10–15m³/h, fly ash / cement.

YJD-B-16: round mouth, 16L / rotation, 1.5kW, suitable for 25–35m³/h, particle materials / limestone.

High-temperature resistant type (YJD-G): 200–500℃, insulation + high-temperature sealing, boiler ash / high-temperature dust.