Howden powers up its manufacturing facilities

Whether it is a power station, mine or a petrochemical, steel or cement plant, air and gas handling are key to efficient – and safe – operation. Howden, the international engineering company, supplies fans, rotary heat exchangers, compressors and gas cleaning equipment which help keep these environments operating effectively. To supply this technology and support its customers across the world, the company, which was founded more than 150 years ago in Scotland, has staff in 17 countries.

Howden Power was established in Johannesburg in 1952, to supply fans for the mining and power generation industries. However, Howden has been supplying main surface fans to South African, Zimbabwean and Zambian mines since 1925. Following a number of strategic acquisitions including fan production and manufacturing companies, the business was listed on the Johannesburg Stock Exchange in 1996 with Howden owning 55 per cent of the company share.

The Howden business units located in Africa are Howden Power, Howden Fan Equipment, Howden Projects and Donkin Fans. What sets Howden Power apart from its competitors is that many of the technologies used in these industries, including mine ventilation and cooling, were first conceptualised by Howden itself.


A recent addition to the shopfloor at Howden Power is a Hankook VTC 5065 E CNC double column boring machine, designed for machining heavy, oversized workpieces such as Howden manufactures. The machine was supplied by Retecon Machine Tools

The Johannesburg operation handles a range of large scale engineered plant and products, including the design and fabrication of turnkey projects. It manufactures equipment including fans, heat exchangers, furnaces and cooling systems, gas cleaning solutions and dust scrubbers.

Howden Power has supplied virtually all the boiler forced draught (FD), induced draught (ID) and primary air (PA) fans for all of Eskom’s fossil-fired fleet of 13 power stations, dating back to the 1960s.

The technologies offered by Howden to the mining sector are changing. South African mines are getting deeper, and conventional air cooling methods using surface chillers and blowers are becoming inadequate and energy-inefficient, making it necessary to use hard ice plants to cool underground air. At 1,500 metres underground, rock surfaces reach 57 degrees, and hard ice plants provide an economical method of cooling.

The diverse capabilities of the business come together in Howden Projects, which provides cost effective turnkey solutions to a variety of industries including mining, manufacturing and power generation. Wherever air cleaning is an issue, a system can be designed to keep particulate levels within statutory levels. Howden can design and supply single units, to integrate with and improve a customer’s existing plant, or become totally involved with the development of new projects from feasibility studies and consultancy right through to a full design, manufacturing, installation, testing and commissioning package with the highest standards of engineering and quality control throughout. A good example is its work at Eskom’s Majuba power station in Mpumalanga, which boasts the world’s largest fabric filter plant – designed, built and installed by Howden Gas Cleaning.


A centrifugal fan impeller is made up of blades, centre and side plates. What is interesting is that 10% of the weight of the impeller is made up of welding

While its specialised knowledge and expertise in industrial applications is recognised throughout the country, the organisation is looking to expand its activities in wider Southern and Central Africa. Many oil, gas and power companies have identified areas such as Mozambique, Angola, Botswana, Zimbabwe and Zambia as areas of huge potential, with even more northern territories such as Tanzania and Kenya also providing promising markets.

Opportunities are plenty at home too, particularly in the light of the environmental regulations that are increasingly impacting the manufacturing sector. South Africa is focused on cleaning up environmentally and driving to green with the new environmental laws and carbon tax proposals for the country, as well as the 2010 Clean Air Act. Companies are now required to manage and monitor emissions and invest in environmental control.

New equipment
Howden Africa invests heavily in its facilities. The 48 000 m² manufacturing plant in Booysens, Johannesburg is no exception.

Manufacturing, refurbishment and upgrading of fans, blowers, heat exchangers and compressors requires some large equipment. A recent addition to the shopfloor is a Hankook VTC 5065 E CNC double column boring machine, designed for machining heavy, oversized workpieces such as Howden manufactures.


A centrifugal fan impeller ready for delivery

The machine, supplied and installed last year by Retecon Machine Tools, has big dimensions. The table, which moves on an oil based system, is five metres in length, has a six metre swing and a maximum turning height of four metres. The table load is up to 60 tons and in total the machine weighs in at 280 tons. The rapid traverse rates on both the X and Y axis are six metres/minute.

“It comes with a vertical milling attachment that allows us to mill and drill where necessary,” said Kassie Carstens, Manufacturing Manager at Howden Power.

“What is on the machine at the moment is a double inlet centrifugal fan impeller for a draft fan. It is a relatively small part in that it only weighs in at about 15.5 tons but once the shaft is attached to it the weight goes up by another 35 tons. We don’t manufacture the shafts but they are supplied to us so we can carry out the final assembly,” continued Kassie.


A centrifugal fan impeller with a shaft

“The centrifugal fan impeller is made up of 24 blades of 8 mm thickness, centre and side plates. What is interesting is that 10% of the weight is made up of welding,” explained Kassie.

“We manufacture about 100 of various impellers for different applications a year and each one takes between 35 to 40 weeks to manufacture.”

Another addition to the shopfloor is a Durma AD-S 30320 CNC press brake, which has a bending force of 320 tons and a bending length of 3 050 mm.


Another addition to the shopfloor is a Durma AD-S 30320 CNC press brake, which has a bending force of 320 tons and a bending length of 3 050 mm

“We needed to upgrade in this department because as you can see we have a number of bending operations to perform. In August we are installing a new Esab plasma cutter, which will replace an existing plasma cutting system.”

“The products that we manufacture and refurbish generally operate in hostile environments so we need equipment with the latest technology that will process the critical components that are a vital part of production, with the greatest accuracy,” concluded Kassie.

For further details contact Howden Power on TEL: 011 240 4000 or visit