Case Studies

Case Study On Rice Husk Conveying System

Client Requirement :

Customer contacted Stratgem for their day-to-day trouble in operating the Rice Husk Conveying system which was supplied by others. Customer also informed that the system was not delivering the required capacity of 5 TPH.

Agenda :

To Study the system of rice husk conveying system for increasing the capacity from 1.5 TPH to 5 TPH and suggesting design to operate it on continuous 5 TPH.

Action Taken :

Detailed system Inspection was carried out by our expert Technical Service Personnel with client’s site team members. Following observations were made during the visit:

• Product – Rice Husk
• Bulk Density – 150 kg/m3
• Temperature - Ambient
• Moisture Content - 8 to 10 %
• Source – Rice Husk dumping Hoppers.
• Destination - Preheater hopper, Having Temp of 900-1000 Deg C and 80-90 mm WC pressure.
• Conveying Type - Roots Blower operated Lean Phase pressure type with Ventury Eductor.
• Conveying Distance - 175 m, (V - 25 m & H- 150 m).
• Conveying Pipe - 150 NB.
• No. of bends - 90 Deg - 8 No, 45 Deg -2 No. Cast Basalt lined
• Roots Blower - Capacity - 3175 m3/hr, Pressure- 9000 mm WC.
• Roots Blower Motor - 132 kW, RPM- 1440,
• Rotary Airlock Valve - Size 600 mm, 20 rpm, Filling Efficiency- 49-50 %, Inlet/Outlet Opening - 600 MM, No of Vanes - 8 Nos. Below each dump hopper (one working one standby), Geared motor, MAKE- PBL, 3.7 KW, RPM 20, directly coupled, Venting pocket arrangement not available.

Running Parameter during Visit :

During the visit it was observed that the Delta Pressure across the ventury eductor was 7000 – 8000 mm WC. Rotary valve had no venting arrangement and Direction of rotation was wrong. The bends used were short radius bends .

1. Ventury Eductor : Pressure drop across the ventury eductor was abnormally high and it should be in the range of 1500 mm to 2000 mm WC maximum. Our Recommendation was to remove the existing ventury eductor and introduce new ventury eductor as per Stratgem design.
2. Rotary Airlock Valve : Empty Pocket venting arrangement to be provided for increasing the filling efficiency. Direction of rotation was set in such a way that empty pockets are vented out during the rotation.
3. Conveying pipe Bends : We recommended to install from small radius bend to 8D bends for smooth conveying operation.
4. Rice husk being abrasive in nature we requested customer to go for a Heavy gauge pipes and rotary valves in wear resistant material of construction.

With the above changes and modification the system was put into operation and client observed drastic improvement in Performance of the system. The capacity increased to the desired result of 5 to 6 TPH .