Some of my designs:


bullet1485 ton Propylene Storage Bullets
watertanksWater Reservoirs
clarifiers1Settling Clarifiers
mounded584 ton Mounded LPG Storage Vessels
paste⌀ 35m Paste Thickener
CFDComputational Fluid Dynamics

Propylene Storage Bullets:

Bullets
5 x 485 ton Propylene Bullets

Propylene is a byproduct of Sasol's production process of synthetic fuel. It is key to produce Polypropylene that is used for plastics and other textiles.
Axis Mechanical Design were asked to design 5 Propylene Storage Bullets that are used to store this chemical. I took leadership of the design process.

The pressure vessels weigh around 485 tons with a capacity of 1 642 500 liters each. The vessels have an internal diameter of 6 meters with an overall length of around 60 meters while only supported on 2 saddles.

At the time, these were the largest steel pressure vessels designed and manufactured in South Africa.

The design conforms to the PER (Pressure Equipment Regulations) and was done according to the ASME Boiler and Pressure Vessel Code, Section 8, Division 2 with all the client's specifications incorporated.
Because of the size of these bullets, platform and walkways had to be specially designed to allow for the deflection and growth of the vessel as a result of weight, pressure and temperature.

During the design some key observations were made which led to the redesigns of potential problematic areas.

The design consisted of the following:

I assisted during the manufacturing period and the vessels were successfully delivered to Sasol Secunda.

More Information:

⌀ 35m Paste Thickener:

Paste
550 ton Paste Thickener

Phosphate is one of the three main nutrition elements in photosynthesis and is a key element in growing crops.

Paste Thickeners are used in the mining industry to separate slurry into solids and liquids. Paste thickeners can obtain much higher solids concentrations compared to conventional thickeners or high rate thickeners.
Paste thickeners have a uniquely high side wall to accomodate a high mud bed level, which contributes to the compression of the solids and hence maximum water recovery.
The rheolodgy of a Paste Thickener's underflow maximises the angle of repose and in turn minimises the area required for tailing dams.

This ⌀ 35m Paste Thickener was fabricated for a Saudi Arabian client to form part of a USD 7.5 billion project to place it as the largest Phosphate project worldwide.

As this is one of the largest Paste thickeners of its kind in the world, I was continuously assisting and advising the draughting office, fabricators and site erection personnel. I visited the site for 2 weeks in the latter stages of the erection to advise on some erection issues.

Structural design accounted for:


Design Methodology:
Tank and Support Structure: Static Structural FEA – Linear Elastic Material Properties.
Access Cat Ladder Structure to bridge: Static Structure & Response Spectra FEA – Linear Elastic Material Properties.
Evaluated according to the Code Calculations and the Allowable Stress Design (ASD) Method of API 650 & ASME BPVC Sect. VIII, Division 2, Part 5.


Research & Development:

Bolted_Thickener
Bolted Thickener

Due to long erection times with conventional welded thickeners, I developed a bolted construction for my present company.

All major parts of the tank is prefabricated and painted in the workshop, where after it is shipped to site. Once on site, a ⌀ 20m thickener can be assembled in +-3 weeks, instead of the average 6-8 weeks.

The bolted thickener was designed as an R&D project. Extensive tests were done on sealants for the bolted joints. A test unit was custom designed for these tests to simulate the actual conditions at a bolted joint in a working thickener.

The bolted thickener R&D was a major success and is one of the companies flagship products due to ease of erection and therefore minimal erection costs.

Design Methodology:
Tank and Support Structure: Static Structural FEA – Linear Elastic Material Properties with Frictionless Contacts and Bolt Pre-Loads.
Area of special interest was the extend of the gap opening up between bolts along the flange length due to sealant’s elastic limitations.
Evaluated according to the Allowable Stress Design (ASD) Method of API 650 & ASME BPVC Sect. VIII, Division 2, Part 5.


LPG Mounded Storage Bullets:

Sunrise Bullets
584 ton Mounded LPG bullets being installed

As the world moves away from "dirty" fuel, an increase in demand of LPG is inevitable.

While at Axis Mechanical Design, I led the design of these mounded bullets.

The bullets were each ⌀ 7m and 67m long, which is very close to the upper limit for these kind of bullets. The mass of one bullet was roughly 584 tons.
This made these pressure vessels the largest ever designed and fabricated in the Southern Hemisphere and in Africa.

What made these bullets special was the fact that they were mounded. This required the design to take into account, not only full vacuum conditions, but also the weight of the mound.

The design consisted of the following:


More Information:

Page Navigation: