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QUANG TRACH 1THERMAL POWER PLANT - 2x600MW

SCREW CONVEYOR CALCULATION

CONTENTS

1 PURPOSE............................................................................................................2

2 TARGET OF DESIGN........................................................................................2

3 STANDARDS AND CODES..............................................................................2

4 UNIT OF MEASUREMENT..............................................................................2

5 DESIGN PARAMETERS...................................................................................2

5.1. Input data......................................................................................................2

5.2. Output data...................................................................................................2

6 BASIS OF DESIGN AND CALCULATION.....................................................2

6.1. Diameter and speed......................................................................................2

6.2. Check minimum diameter for lump size limitations....................................3

6.3. Power............................................................................................................3

7 DESIGN & CALCULATION RESULTS...........................................................4

8 APPENDIXES.....................................................................................................4

QT1-PVE-00HTK-M-M5A-0010 PAGE: 1 of 24



1 PURPOSE

Screw conveyors are bulk material transporting devices capable of handling a great variety of materials which have relatively good flowability.

The key to successful screw conveyor design is a thorough knowledge of the characteristics of the material to be handled.

2 TARGET OF DESIGN

Design is to provide the optimal engineering solution meet to safety, reliable & stable operating conditions for system.

3 STANDARDS AND CODES

- ANSI/CEMA 350-2003 – Screw conveyors for bulk materials.

4 UNIT OF MEASUREMENT

The unit of measurement in the design shall be SI unit (International System of Units).

5 DESIGN PARAMETERS

5.1. Input data

- Type of material to be conveyed.

- Maximum size of hard lumps.

- Percentage of hard lumps by volume.

- Any additional factors that may affect conveyors or operations.

- Working time.

- Distance material to be conveyed.

- Capacity required.

5.2. Output data

- Screw diameter.

- Conveyor speed.

- Power required.

6 BASIS OF DESIGN AND CALCULATION

6.1. Diameter and speed

In order to determine the size and speed of a screw conveyor, it is necessary first to establish the material code number (see Table 8-1 in Appendixes). It




will be seen from what follows that this code number controls the cross-sectional loading that should be used.

Using known capacity required in cu.ft./hr., material classification, and % trough loading (30%B) determine the screw diameter and conveyor speed from Table 8-2 in Appendixes.

For screw conveyors with screws having standard pitch helical flights the conveyor speed may be calculated by the formula:

6.2. Check minimum diameter for lump size limitations

The size of a screw conveyor not only depends on the capacity required, but also on the size and proportion of lumps in the material to be handled. The size of a lump is the maximum dimension it has. If a lump has one dimension much longer than its transverse cross-section, the long dimension or length would determine the lump size.

The character of the lump also is involved. Some materials have hard lumps that won’t break up in transit through a screw conveyor. In that case, provision must be made to handle these lumps. Other materials may have lumps that are fairly hard, but degradable in transit through the screw conveyor, thus reducing the lump size to be handled. Still other materials have lumps that are easily broken in a screw conveyor and lumps of these materials impose no limitations.

Using known screw diameter and percentage of hard lumps, check minimum screw diameter from Table 8-3 in Appendixes, where three classes of lump sizes as follows:

- Class 1: A mixture of lumps and fines in which not more than 10% are lumps ranging from maximum size to one half of the maximum; and 90% are lumps smaller than one half of the maximum size.

- Class 2: A mixture of lumps and fines in which not more than 25% are lumps ranging from the maximum size to one half of the maximum; and 75% are lumps smaller than one half of the maximum size.

- Class 3: A mixture of lumps only in which 95% or more are lumps ranging from maximum size to one half of the maximum size; and 5% or less are lumps less than one tenth of the maximum size.

6.3. Power




Where:

: Total power (kW)

: Power required to run an empty conveyor (kW)

: Power required to move the material (kW)

: Overload factor

: Overload factor

6.3.1. Power required to run an empty conveyor

Where:

: Total length of conveyor (m)

: Operating speed (rev/s)

: Conveyor diameter factor

: Hanger bearing factor

6.3.2. Power required to move the material

Where:

: Capacity of conveyor (m3/s)

: Density of material (kg/m3)

: Flight factor

: Material factor

: Paddle factor

7 DESIGN & CALCULATION RESULTS

See attached documents.




8 APPENDIXES

Table 8-1. Material Characteristics







Table 8-1. Material Characteristics (cont.)





















































- Table 8-2







Table 8-3


Engineering

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