Product category:
Metals and Minerals Processing News
News Release from: ABB Automation Tech (Drives and Motors) | Subject: Castle Cement
Edited by the Processingtalk Editorial
Team on 11 April 2008
ABB drives the most modern cement kiln
in Europe
The most modern European cement kiln, at the Castle Cement Padeswood works in North Wales, is being speed controlled by two 300 kW ABB industrial drives
The drives work in a master-follower arrangement Here, both drives have an individual gear box which in turn drives a common girth gear that is attached to the kiln shell
This article was originally published on Processingtalk on 6 Aug 2003 at 8.00am (UK)
Related stories
Record breaking electric car to go the distance
ABB has found a novel way to put its drives and motors to the ultimate test by providing the main drive system for the British challenger to to the world electric land speed record
Data for over 500 motors now available online
Motor performance curves, data sheets and drawings for low voltage AC motors, from 0.055 to 710 kW, are now available from the ABB website: data for more than 500 motors to be downloaded or viewed
The benefits of this arrangement mean that the speed of the drives change as the kiln feed increases or decreases.
"This speed control is essential for the quality of the product" stresses the Castle Cement plant electrical engineer, Dave Jones.
Another benefit for Castle Cement is that the ABB AC drives, with Direct Torque Control (DTC), offer proven torque control and superior speed control accuracy, ensuring uninterrupted and stable running, irrespective of the kiln speed or the kiln load.
Further reading
High voltage motors are standardised for OEMs
A new range of standard high voltage induction motors, ready for delivery within days, has been launched by ABB: lower priced than engineered motors, these are ideal for OEMs needing standard product
ABB becomes preferred supplier for Imerys Minerals
Aiming to save downtime costs of up to GBP10,000 per hour, Imerys Minerals in Cornwall has entered an agreement with ABB to supply motors and drives to its UK plants
Guide to ATEX 137 dos and don'ts
"ATEX 137 dos and don'ts" is a step-by-step guide to the responsibilities of end users operating motors in potentially explosive atmospheres
Power supply failures and other special occasions result in the need to restart the kiln.
Restarts, requiring a very high starting torque, are easily achieved with DTC.
The superior control characteristics of the drives enable accurate control of the kiln, thus optimising the fuel consumption and the production flow.
Not only has the new GBP68 million kiln 4 installation increased production at the works from 500,000 to over 800,000 tonnes of cement per year, but it operates to the very highest levels of environmental control, performance and energy saving.
Central to the greatly improved energy saving of the 65 metre long kiln is an ABB industrial drive used on the ID fan, which at 2MW is the largest drive installed at Padeswood.
The ID fan, located near the preheater tower, draws gases through the kiln, precalciner and cyclones before emitting them through the exhaust stack.
There are three fans involved in the kiln process and each one is controlled by an ABB industrial drive.
Apart from the 2MW ID fan, there is an exhaust fan, rated at 750kW that takes gases to the atmosphere via the dust collecting bag filters and a cooler fan rated at 560kW which takes the cooler exhaust gases to atmosphere.
A further four fans, rated 110 kW, 160 kW, 200 kW and 250 kW push the air into the grate cooler to reduce the temperature of the hot clinker to a set point.
All these airflows have to be adjusted and controlled as atmospheric conditions, process conditions and ventilation needs greatly effect the flow requirements.
The control method employed has a major effect on the running costs.
For example, a damper with a fixed speed motor is the least energy efficient solution and the ABB industrial drives have proved to be the most energy efficient.
"We have about 3.5MW of variable speed drives on fan applications and we would expect a 25 to 30% saving over conventional technology.
Low voltage AC drives are primarily used for load matching resulting in significant energy saving as well as for reduced maintenance benefits," says Dave Jones: "Maintenance is considerably reduced because many of the drives have replaced DC drives and slip ring motors which required replacement carbon brushes costing over GBP7,500 per year in total".
By installing the ABB industrial drives on the kiln, the ID fan and the other fans, Castle Cement hopes to improve its profitability through increased system availability, energy savings and reduced maintenance.
Additional benefits of the variable speed drives include total process controllability and the elimination of motor noise and fan vibration.
ABB has supplied to Castle Cement, low voltage AC drives for over 150 other applications including mills, pumps and conveyor belts.
In addition, the plant uses some 450 electric motors.
An added bonus, according to Dave Jones, is the location of ABB Drives Alliance partner and supplier of the drives, Central Electrical.
"Its ability to respond with spare parts and technical advice along with access to their technical teams, training and trouble shooting is beneficial".
Meanwhile the site overall improved performance is attributed to the use of alternative fuels, in which Castle Cement has been a pioneer.
Alternative fuels to be used at Padeswood include Cemfuel, which is processed from the residue of recycled waste solvents and Profuel, which comprises paper and plastic wastes.
In the future, vehicle tyres will also be used as an alternative fuel.
The opening of the new kiln has resulted in the closure of three existing kilns at Padeswood and two wet kilns at the Ribblesdale works in Lancashire.
This will reduce the Castle Cement carbon dioxide emissions by 17.5 per cent per tonne of cement produced against 2004 performance.
Acid rain gases at Padeswood will be reduced by a staggering 75 per cent.
Since the new kiln came into operation, dioxin levels have been reduced to be amongst the best in the world while sulphur dioxide emissions are down by over 90% and carbon dioxide by 20%.
Mike Eberlin, managing director of Castle Cement said: "Kiln 4 will lead to major improvements in the local environment.
It will also help reduce the Welsh dependence on landfill sites while using waste both for cleaner production and lower energy consumption".
The new kiln ensures an increased supply in the marketplace of light-coloured cement.
The light colour is especially attractive to precast concrete manufacturers as it can allow a brighter finished product and when used, less pigment may be necessary to arrive at a specified shade.
Castle Cement is the UK arm of HeidelbergCement, the world-wide building materials group.
Heidelberg Cement was founded in Germany in 1873 and now employs 76,000 people in 50 countries.
In the UK, around 1,000 people work at Castle Cement plants at Ketton in Rutland, Ribblesdale in Lancashire and Padeswood in north Wales, as well as at the head office in Birmingham and at marine terminals in Avon and Humberside.
• ABB Automation Tech (Drives and Motors): contact details and other news
• Email this article to a colleague
• Register for the free Processingtalk email newsletter
• Processingtalk Home Page
Search the Pro-Talk network of sites
