D NIEMANN & ASSOCIATES
STRUCTURAL STEEL DESIGNERS OF BULK MATERIALS HANDLING PLANTS
Our experience in structural design and industry exposure stretch over a period of 45 years across a broad spectrum of international projects, in the Minerals and Metals, Mining, Power Generation, Cement, and Petrochemical Industries.
We are actively involved from inception to handover by travelling locally and abroad liaising with clients and their professional team, before proceeding with any design work.
All design work undertaken is done by registered Engineers.
Also, multidisciplinary design work awarded to sub-contracting consulting engineers is executed by registered engineers, or work of a lesser design nature is done by skilled personnel supervised by a registered professional engineer.
The latest codes of practice and amendments are observed and used for the specific country where structures will be constructed, as well as all related client specifications. Project-specific design criteria and/or other related documents, site climatic conditions, and client requirements are adhered to.
Safety and ergonomics are important aspects to us, and therefore we set out to achieve a fine balance between safeness and soundness on the one side, while always keeping the economic factor in mind for the benefit of our clients.
We apply internationally accepted norms and engineering practice as well as sound engineering judgment to all work undertaken.
The latest and most up-to-date computer engineering software is used to ensure optimum design results.
We are BEE compliant level 4 where required for South African projects.
ABOUT US
Our company aircraft are hangared at Springs Airfield approximately 30 km east of Johannesburg, from where it is flown by our in-house pilot to our clients’ premises, often remote construction sites, power stations and mines in Southern Africa, using bush pilot, mountain flying and STOL (short take off and landing) techniques, especially on gravel or grass strips.
Flying to remote destinations shorten travel times considerably, enabling us to serve our clients more effectively by resolving their complex mining, storage and production problems sooner.
We are mainly involved in the mineral and metals, mining, power generation, cement and petrochemical environment, and for the past ten years approximately eighty percent of our work has been in the coal mining sector.
SERVICES
CAPABILITY PROFILE
Provide design man hour estimates.
Pre-engineering conceptual design input, steel tonnage estimates, tenders, studies/feasibility studies.
Plant/site audits for aged structures or questionable fabrication and/or installation work – issuing formal reports on request.
Structural Design reviews and audits issuing formal reports on findings and recommendations.
Site inspections, troubleshooting and recommendations.
STRUCTURAL STEEL DESIGN INCLUDING:
Foundation loads
Finite Element Analysis where required
Structures subject to vibration and impact
Drawing Office liaison and attendance (i.e. our clients’ Drawing Offices)
Issue enlarged connection detail sketches
Enlarged Baseplate and Holding Down Bolt details
Plate work and Containment Structures
Bulk Materials Handling Machines
E.O.T. Crane Buildings
INDUSTRY EXPERIENCE
Structural steel design incorporating load assessment, structural analysis, stress and strain analysis, as well as observing deflection limits and the various serviceability aspects. Dynamic, modal, harmonic, seismic/earthquake analysis done for structures subject to vibrating equipment, dynamic force excitation or in earthquake zones. Structural design audits are undertaken for suspect structures or designs, or where independent design audits have been requested.
Although our experience cover various types of structures and applications as can be seen under the ‘Fields of Expertise’ heading, we mainly concentrate on Bulk Materials Handling Projects and obviously any related structural design required to provide our clients with an all inclu
Bulk Materials Handling and Process Plants include inter alia the following products (but is by no means an exhaustive list):
In plant belt conveyor systems, from feeding material onto tail end, groundline modules, elevated groundline modules, gantries and trestles, transfer towers, horizontal and vertical gravity take up structures, take up towers, drive houses, fixed tripper structures etc.
Long overland belt conveyor systems ranging from 1000 meters to 12,0 kilometres designing for large dynamic and transient belt forces exerted on steel supporting structures including inter alia a 25,0m high by 50,0 ton gravity take up tower, belt turnover stations, plus belt frequency calculations if required.
Bulk material handling machines designed to European and international codes, trippers, slewing luffing stackers, linear and circular. Linear bridge and portal scraper reclaimers as well as circular bridge scraper reclaimers. Radial luffing boom stackers.
Stockpile gantries and domes, camel back gantries and ship loader tripper gantries.
Storage bunkers, elevated bins, tanks, hoppers, silos, petroleum tanks, dewatering tanks, clarifier tanks, ultraceps thickeners, etc.
Rapid Load Out Stations, for rapid train loading.
Dust extraction plants including baghouses, chimney stacks, large diameter ducting, precipitation plant structures.
Shiftable conveyors on modular frames for waste dump extension, head end with take up and drive units on steel pontoons spreading the load and thereby reducing the soil pressure by utilizing the very low bearing capacity of the uncompacted waste dump materials to its full.
Impact load calculations for run of mine (ROM) material dumped onto a static grizzly grid in a tip pit.
Dynamic and frequency calculations for structures supporting vibrating equipment, or subject to harmonic force excitation.
Industrial buildings, workshops, warehouses and electric overhead crane buildings.
Design against brittle fracture in sub-zero temperatures.
Roller supported mills (RSM), marine and land in the diamond industry.
Mining Conveyances and Shaft steelwork including overwind headgear conditions.
RECENT PROJECTS
List of larger projects undertaken during past 10 -15 years, excluding numerous smaller projects, and including design responsibility / share.
FIELDS OF EXPERTISE AND PREVIOUS INDUSTRY EXPOSURE
· Long overland troughed belt conveyor systems.
· ‘In plant’ conveyors including all associated structures and ancillary buildings.
· Dump / tailings - shiftable / movable conveyors on pontoons.
· Washing and screening plants.
· Coal mine ROM tip/pit structures, grizzlies etc.
· Structures subject to vibration, cyclic harmonic excitation and impact calculations.
· Containment structures, bunkers, bins, hoppers, silos, surge bins, chutes and tanks.
· Own calculations of bulk material pressures derived from material properties, internal friction angle / angle of repose, Rankine / Coulomb / Jansen / Jennicke, silo emptying spiking pressures for waist / ringbeam design etc. Deep silos to DIN 1055 for material pressures, alternatively Australian or Eurocodes.
· Machines designed to ISO 5049 and FEM – Trippers, transfer cars, stackers and reclaimers, both circular, linear and portal.
· Air extraction filter plants, baghouses including chimney stacks, large diameter thin shell ducting and electrostatic precipitator extraction plants.
· Thickeners, ultracep thickeners and pin bed clarifiers.
· Rapid Load Out Stations (for rapid train loading up to approximately 10 000 tons in a relatively short period of time)
· Cement plants, Ferro smelter plants and petrochemical structures and tanks.
· Feasibility studies, tenders, estimates.
· Lifting / Cranage exercises including lifting beams, spreader beams and lifting tackle designed in compliance with the Mines and OHS Acts.
· Strandjacking of heavy lifts in the range 800 ton to 1 000 ton single lifts.
· Retrofit and refit of Bulk Materials Handling machine equipment, which is often far more economic than replacing a complete BMH system of which a large structural component percentage still has an adequate lifespan.
· EOT (Electric Overhead Travel) Crane Buildings.
· We are familiar with, and conversant in numerous International Design Codes, both metric and imperial units, including severe earthquake zones where large seismic forces have to be designed for and redundancies built into Structures in countries such as Latin America, Chile, Mexico, the Middle East and East Block Countries.
· Investigations are undertaken into the non-conformance to clients' specifications, of Structural Steel structures which are not fit for purpose, by reporting on the following:
- Findings / problem statement
- Immediate risks and safety considerations
- Review design calculations
- Propose corrective and preventative measures
GALLERY
