8/20/2019 Howden Background

1/2

Howden integrated annual report 2013

40

Material issues continued

Some Howden products and their positive effects on the

environment

Indirect environmental contributions

One of our key strategic focus areas is to develop productsand services that assist our customers in reducing their

environmental impacts and carbon footprints. The examples

below illustrate a few ways in which we accomplish this

objective.

Dust collection and flue gas cleaning

Howden has a selection of dry dust collection and scrubber

technologies that can be employed as specied by the

customer. Most of our gas-cleaning systems are supplied on a

turnkey basis, and include design and detail engineering,

supply and manufacture, electrical control and instrumentation,

plant erection commissioning and handover to the customer.

Scrubbers

Howden’s wet, dry and semi-dry scrubbing solutions are

proven options for gaseous emission and particulate control

and suitable for use on high-temperature applications.

Engart dust scrubbers

Engart dust scrubbers are among the leading dust-collection

systems in the coal-mining industry where airborne dust is a

risk to health and safety.

Dust-laden air is drawn into the dust extractor and mixed with

water at the impeller and in the chamber. The dust/air/water

mixture is then drawn around the motor and caught in asteel-woven mesh which is continually washed by a multi-

nozzle spray bank. The sludge is pumped away and dust-free

air is exhausted.

With dust-capture and scrubbing ef ciencies of 99% of total

dust, Engart dust scrubbers offer unsurpassed performance

levels.

Fabric filter plant

Our fabric lter plant is suitable for application requirements

where emissions below 10 mg/m3 are required. Two bag lter

technologies are offered, either high-pressure reverse pulse jet,

or low-pressure reverseow.

Reverse pulse lter technology is particularly appropriate to

applications where space for the plant is limited. The reverse

pulse jet lter offers high performance and low operating cost,

making it a popular choice in many demanding industrial

applications.

Example 1 – wet scrubber systems

 The environmental control division installed two primary off-gas

scrubber plants, each with a maximum capacity of  40 000

Nm³ /hour and average off-gas volume from the furnace of

23 524 Nm³ /hour at 500° C (peak temperatures of 1 200° C)

for a steel industry client. The main role of this system was toremove the point of generation dust particles from the off-gas.

 The carbon monoxide (CO) rich gas is cleaned and

combustible gas transferred to an electrical generation plant.

Due to environmental legislation, the scrubber system has to

clean the inlet dust load (150 g/Nm3 ) off-gas to below

30 mg/Nm3. An overall scrubber ef ciency of 99,98%. In

addition, off-gas has to be cooled to around 40° C to reduce

moisture in the gas.

 The cleaned off-gas from the exhaust is then channelled to the

electrical generation plant and eventually discharged into the

atmosphere in line with the minimum air quality standards of

emissions as set by the National Environmental Management

 Act, No 39 of 2004 and Occupational Health and Safety Act,

No 85 of 1993.

Electrical power generated from the exhaust off-gas is

6 to 9 MW, serving as additional power to the customer plant.

 This is equivalent to 54 MWh of energy per annum which has

an indirect reduction of at least 1 000 tonnes of CO2 per

annum.

 

Example 2 – reducing dust particulate matter at coal-fired power stations

Most power generation in South Africa is from coal-red power

stations, which generate huge quantities of ash. Most of this

gets separated, removed and treated as process waste. Power

stations manage these older-technology plants as well as they

can, but substantial quantities of ash are still dispersed into the

atmosphere as y ash.

 The sheer magnitude of power-generation requirements result

in some 114 kg/h of y ash per megawatt (MW) of power

generated. In recent years, our projects division has installed

our pulse jet fabric lters at local power-generation plants – an

effective 672 000 m2 of ltration material or the equivalent of

84 football pitches in area. Our installed pulse jet fabric lters

capture 865 500 kg of ash every hour – about 7,5 million

tonnes per year. This demonstrates ash-removal ef ciencies of

99,9%, and a meaningful contribution to our customers’ efforts

toward cleaner South African skies.

8/20/2019 Howden Background

2/2

Howden integrated annual report 2013

41

Chillers and cooling plants

Howden offers turnkey chiller plant installations, including civil

work, peripheral plant, and electrical and control systems to

cool mines. We use ammonia in all installations as this is an

ef cient natural refrigerant with zero global warming potential

and long-term availability.

For enhanced safety, Howden ammonia chiller plants are built

to strict industry and statutory codes. They are designed and

developed inhouse, and packaged units are based on

simplied refrigeration processes, eliminating the need for

economisers or gearboxes for duties up to 9,5 MW (R). No

refrigerant pumps or refrigerant pump-put facilities are required

and the refrigeration process design eliminates the possibility of

corrosion of internal components of the plant.

Example 3 – mine cooling by ice

 This is an energy-saving technology applied in deep-level

mines which uses hard ice to cool the mine. The environmental

control division has installed a 30 kg/sec 10 m W(r) hard ice

plant, using plate ice makers and ammonia refrigeration screw

compressor sets. Using hard-ice technology instead of vacuum

ice or conventional water chillers signicantly reduces water

ow rates with considerable savings in power consumption.

We advise clients from a variety of industries where power

saving is important. In brewing operations, for instance, our

new variable ratio compressors allow compression energy to

be optimised with varying environmental and process

conditions. In large-scale sewage treatment plants, our highly

ef cient, new-generation turbo blowers reduce the energy

required for supplying pressurised aeration air required for

biological treatment.

Energy efficiency

Fan design is both an art and a science. Our skilled and

experienced engineers are dedicated to carefully analysing and

solving each industry’s specialised needs.

Example 4 – power savings on industrial and mine 

fans

In recent years, Howden successfully retrotted 52 fans in

industrial applications to increase machine ef ciency, reducing

consumed power by about 25%. The new installations

produced (on average) 56 kW reserve per fan – totalling almost

3 000 kW for the 52 fans. Indirect reduction in SO2 emissions is

120 tonnes at power stations.

Howden’s fan equipment unit has been active in manufacturing

and installing radial vane ow control devices in mining main

surface fan applications. The purpose of the project was to

reduce fan power consumption during peak hours, increasing

when there is low demand. Annual savings on 20 mine surface

fans totalled 16,5 MWh of electricity. This equates to indirect

reduction of 370 tonnes of SO2 emissions per annum.

 These examples demonstrate that Howden products make an

extensive contribution to a cleaner planet every year.

Transformation and society Economic transformation and empowerment

Howden is fully committed to economic transformation and

empowerment. In 2013 we were once again certied as a

level 4 contributor in terms of the dti codes of good practice

scorecard.

2013 2012 2011

Level 4(72,35 points)

Level 4(66,29 points)

Level 4(66,5 points)

 The Group is recognised as a value-adding supplier, allowing

Howden customers to claim 125% on each rand of

procurement with Howden.

 The Group is committed to further continuous B-BBEE

transformation and is actively considering options and plans for

transition to the new DTI B-BBEE Codes of good practice.

Key areas of focus

Management and control

Howden has achieved an 88,3% (2012: 85%; 2011: 82%)

compliance rating against this element of the code and aims to

improve this in future by people recruited inside and outsidethe Company. Howden successfully identies, appoints,

mentors and trains talented individuals for top management

positions.

Employment equity

We continue to improve this rating from the disappointing 2011

rating.

2013%

2012%

2011%

38,3 36,9 18

 Although steady progress has been made in appointing

HDSAs into non-technical positions, the skills crisis in the

engineering sector presents challenges in improving this rating

materially in the short term. This is compounded by the fact

that engineering has not traditionally attracted skilled females

into the sector. Every effort is made to accommodate disabled

people in productive employment activities.