Previous in Forum: RT on Annular Plate of Tanks   Next in Forum: Gas Compression & Combustion Efficiency
Close
Close
Close
8 comments
Active Contributor

Join Date: Nov 2008
Posts: 23

Design of Silo for Storing Rice

02/23/2012 8:05 AM

Gentlemen of the CR4,

I need to design a cylinderical silo to store Rice. Can any one help me with an appropriate Code or standard for this design. I have looked through ASME and API but could not find any.

It is suposed to be made with A36 steel.

I also need an applicable software.

Regards,

Chike

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".
Anonymous Poster #1
#1

Re: Design of Silo for Storing Rice

02/23/2012 8:12 AM
Register to Reply
Guru

Join Date: Jun 2010
Posts: 986
Good Answers: 14
#2

Re: Design of Silo for Storing Rice

02/23/2012 11:04 AM
Register to Reply
Guru

Join Date: Mar 2007
Location: by the beach in Florida
Posts: 31859
Good Answers: 1751
#3

Re: Design of Silo for Storing Rice

02/23/2012 9:10 PM
__________________
All living things seek to control their own destiny....this is the purpose of life
Register to Reply Score 1 for Off Topic
3
Power-User

Join Date: Dec 2010
Posts: 377
Good Answers: 20
#4

Re: Design of Silo for Storing Rice

02/23/2012 9:37 PM

Welded Silos Specifications

I. SCOPE:

The following specifications cover the process for welded silo fabrication.

II. CODES:

These specifications are used in conjunction with the following codes:

  • AISC - American Institute of Steel Construction
  • AWS - American Welding Society
  • UBC - Uniform Building Code
  • FDA - Food and Drug Administration
  • OSHA - Occupational Safety and Health Administration
  • ASTM - American Society for Testing and Materials
  • SAE - Society of Automotive Engineers
  • SSPC - Steel Structures Painting Council

III. Design Criteria:

  1. Standard wind design is for 100 MPH wind velocity based on the UBC 1999 Edition. Combined height, exposure and gust factor coefficient is based on Exposure B. A horizontal force shape factor of 1.4 is included.
  2. Seismic design is based on UBC 1999 Edition. When designing a silo for a particular seismic zone, the load producing the highest stresses comparing wind and seismic forces will control the dynamic portion of the design.
  3. Combined live, dead, and roof loads shall be uniformly distributed, with all nozzles, manhole and filter locations designed for a minimum of 200 lbs. concentrated load. Live and dead loads to be a combined minimum of 24 lbs. psf. Roof is not designed as a working platform. Standard roof will have a 10 degree slope for water drainage.
  4. Silo design is based on the critical buckling formula from the book titled Structural Engineering Handbook by Gaylord and Gaylord (Boardman formula).
  5. Silos are designed to atmospheric pressure as a standard. Silos are capable of withstanding normal pneumatic fill line pressures of 0.5 oz. per square inch vacuum and maximum of 4.0 oz. per square inch of pressure.
  6. LEMANCO Welded Industrial Silo`s are designed for loads as follows: The silo may be filled to capacity with bulk materials at design unit weight having a material repose angle of 30 degree and a coefficient of friction of 0.7. This combination of material repose and friction coefficient results in a more severe condition than is normally likely to be encountered.
  7. Loads are based on center discharge and near center fill. Other arrangements will alter design conditions.
  8. Silos can be designed for either funnel flow or mass flow.
  9. Due to the wide variation in Building and Zoning Codes and their interpretations, Chief Industries, Inc. does not warrant The Lemanco Product or collateral materials or equipment to comply with any Building or Zoning Code requirements, permit requirements, design procedure, design load, material or equipment requirements, fabrication procedure, or work procedure except those expressly provided herein or in the order. Costs of any additions, deletions, modifications, or changes that may be required to comply with any building or zoning code requirement, permit requirement, design procedure, design load, material or equipment requirement, fabrication or work procedures which are not expressly provided herein or in the order are paid by buyer. When the size, shape, general characteristics, or design are specified by the Buyer, the Seller is not responsible for the suitability, adequacy, or legality of the design.
  10. Chief Industries, Inc. does not design and is not responsible for the design, materials or workmanship of the foundation unless agreed. The BUYER assures himself that adequate provisions are made in the foundation design for the loads imposed by LEMANCO PRODUCTS (See Anchor Bolt Plan for magnitude and direction of column reactions), or other imposed loads, and the soil bearing capacity and other conditions of the building site. Please note that all above design conditions were chosen to cover most standard situations. All other criteria can be evaluated per application and requirement.

IV. Material Specifications:

  1. SHEET - Carbon steel shall conform to or shall be at least equal to ASTM 569 Commercial quality.
  2. PLATE - Carbon steel plates 3/16" or thicker shall conform to or at least be equal to the requirements of ASTM A36 with a minimum yield strength of 36,000 psi.
  3. ROLLED STRUCTURAL SHAPES - Rolled structural shapes shall conform to ASTM A36.
  4. PIPE - Structural pipes shall conform to ASTM A53 Grade B.
  5. BOLTS -
    A. Miscellaneous bolts are stainless steel and meet the minimum requirements of SAE Grade 5.
    B. Structural bolts meet the minimum requirements of ASTM A325.
  6. HANDRAILS, LADDERS, SAFETY CAGES AND PLATFORMS -
    A. Handrails, ladders, cages and platforms are designed to meet OSHA requirements and are welded units to minimize field erection.
    B. Standard equipment includes aluminum handrails and carbon steel ladders, cages and rest platforms galvanized or painted.

V. Manufacturing Specifications:

  1. WELDING
    A. When specified, all structural welding shall conform to the latest edition of AWS using AWS certified welders.
    B. Shell seams shall be a minimum of 85% penetration using .045 gauge ER70XX welding wire with a semi-automatic MIG Welder and copper backed internal sizing rings.
  2. SURFACE PREPARATION
    A. All weld surfaces with sharp edges are ground, any undercuts will be repaired and ground. All weld spatter will be removed and exterior surfaces shall be grit blasted prior to painting per SSPC-SP7.
    B. Gritblasting per SSPC-SP 6 or SSPC-SP10 is available for interior or exterior walls when specified.
    C. SSPC-SP 10 near white is used for FDA applications. (All interior weld seams are ground flush)
  3. COATINGS CARBON STEEL
    A. Silo exterior shall be coated (when required) with minimum 2.0 mils of rust inhibitive gray primer and 1.5 mils minimum of polyurethane finish coat. Epoxy coating up to 10.0 mils is available for interior or exterior coating when specified.

VI. Quality Control:

  1. All welds are visually inspected for air holes, pinholes, undercut, penetration and satisfactory finish. Dye penetration inspection shall be performed on all liquid storage silos as standard (refer to testing data). All inspections are documented per Manufacturers Quality Control Policy and Procedures Manual.
  2. Quality Control inspection points are placed at critical intervals during the manufacturing process.
  3. Final inspection is made before and after loading for shipment with photographs.

Standard Silos Include

  • Funnel flow design.
  • 10 degree slope on deck roof.
  • 20 inch diameter center fill dome with cover plate.
  • 12 inch diameter flange discharge with 2 foot 6 inch clearance.
  • 3 foot x 6 foot 8 inch steel access door with louver (on skirted tank, except when skirt height does not permit).
  • Lifting lugs.
  • Exterior primed with epoxy and top coated with polyurethane.
  • Three sets of standard engineering drawings provided.
  • Standard Hoppers.
  • Standard silo diameters: 7, 8, 9, 10, 11.6, 12, 13, and 14 feet.
  • Standard silo heights are in nominal 6 foot increments.
  • Standard hoppers are symmetrical with outlet. Larger or smaller outlets are available per customer requirements.

I hope this will help

Register to Reply Good Answer (Score 3)
Active Contributor

Join Date: Nov 2008
Posts: 23
#5
In reply to #4

Re: Design of Silo for Storing Rice

02/27/2012 6:47 AM

Thank you'

I still need your assistance, because I need to design another hopper for the storage and discharge of portland cement. The size is 3.048m dia x 4.12 meter TT. Head is 2:1 ellipsoidal, and the material is A516-70.

I heve been using the Janseen equation for the determination of pressure components but have ran into a problem. I need to know the value of the internal friction angle.

The silo will be air assisted in the disharge. The air operating pressure is 30psig.

I will appreciate if you can help me out.

Chike

Register to Reply
Power-User

Join Date: Dec 2010
Posts: 377
Good Answers: 20
#6
In reply to #5

Re: Design of Silo for Storing Rice

02/27/2012 8:57 PM

I think you need a permanent technical assistanat who can find all the details for you and you can earn the name and fame for your design.

Register to Reply
Guru

Join Date: Jun 2011
Location: Phnom Penh
Posts: 4019
Good Answers: 102
#7

Re: Design of Silo for Storing Rice

02/28/2012 8:20 PM

Mukesh provided you with some excellent information Chike.

In addition to the sound advice in #6, I would recommend that you seek out and visit some extant silos close to your locale. Perhaps your client (employer) has similar assets in service.

Your designs will also have to comply with the operator's procedures and the environment of operation.

Solar Eagle's silos pictured in #3 look like they are galvanised. Surface protection is another issue.

From Mukesh's #6

V. Manufacturing Specifications:

COATINGS CARBON STEEL

A. Silo exterior shall be coated (when required) with minimum 2.0 mils of rust inhibitive gray primer and 1.5 mils minimum of polyurethane finish coat. Epoxy coating up to 10.0 mils is available for interior or exterior coating when specified.

Pretty specific.

Go and look at some.

What is you location Chike?

__________________
Difficulty is not an obstacle it is merely an attribute.
Register to Reply
Active Contributor

Join Date: Nov 2008
Posts: 23
#8
In reply to #7

Re: Design of Silo for Storing Rice

02/29/2012 8:56 AM

I have visited the location of our client here in Nigeria.

I have also made remarkable progress on the design

Thank you for the advice.

Chike

Register to Reply
Register to Reply 8 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".
Copy to Clipboard

Users who posted comments:

129CBRider (1); Anonymous Poster (1); Chike Nwachukwu (2); Mukesh0861 (2); SolarEagle (1); Wal (1)

Previous in Forum: RT on Annular Plate of Tanks   Next in Forum: Gas Compression & Combustion Efficiency

Advertisement