Cement Pre-Heater Tower

Transcription

1 Cement Pre-Heater Tower Guideines Contents 1. Background 2. Panning and Design 3. Inspection and Cean Down 4. Wrecking of Lining 5. Refractory Instaation 6. Near Miss/Hits 7. Longer Term Compiance with any guidance set out in this document does not absove the user from his ega duties under the Heath and Safety at Work etc Act 1974 to form his own site specific assessment of his workpaces and operations and to provide accordingy for such matters. 1. BACKGROUND A Workshop was hed on the 26th October 2012 with the participation of designers, scaffoders, refractory speciaists, pant engineers & managers and safety speciaists. The aim of the workshop was to buid on earier guidance on Panned and unpanned maintenance on kins and pre-heaters and to work together to identify good practice and improve safety for a. This document concentrates on a reativey narrow set of heath and safety priorities specific to the wrecking and subsequent instaation of pre-heater tower refractory inings in the United Kingdom. made in earier guidance on kin maintenance and PPE may aso appy to the wrecking of inings, for exampe on co-ordination, communication, management, supervision, emergency procedures, housekeeping, CDM reguations, isoation and PPE seection. mpa cement Minera Products Association

2 2 - Cement Pre Heater Tower Guideines 2. PLANNING AND DESIGN Pans shoud incude measures to contro the risks posed by faing refractory and other materias such as scaffoding poes and bricks; contro the fumes and fash generated by weding activities; resove potentia safety conficts between different groups of contractors working in the pre-heater tower (e.g. weders or those working overhead); ensure that safe working oads of patforms are observed; contro the deivery and storage of contractor materias; faciitate materias handing and good house keeping; and to maintain good occupationa heath. Advance Panning Scaffod beam doors Certain engineering measures may need to be put in pace prior to the shutdown. These reate to improved access, faciitation of safer working practices and the provision of access ports for the instaation of the Pre-Heater Tower Safety Net. It is recommended that increased research is carried out on the effects of aternative fues on refractory and anchor performance. Additionay CARDOX use has increased with the use of aternative fues and this has knock-on consequences for the iner. Above the Riser: Provide a ifting beam aong with a coffin door to faciitate working downwards. Access Doors: Shoud be designed to faciitate the instaation of patforms and aow the recovery of casuaties by SKED/ Stretcher. Additionay the coser the door to the top of the cycone, the ower the risk associated with faing refractory. Subject to structura constraints, increasing the number of doors reduces the oading on the working patform, as the distance between patforms can be reduced. Access Routes: Faciitate the fow of materias and equipment (incuding automated wrecking machinery) to and from the access doors by improving access routes. Reduce manua handing injuries and the risk posed by faing materias by designing routes and by providing hoists etc. to faciitate the movement of scaffoding poes and boards; and by designing wrecked materia fow routes out of the preheater tower and then down to the ground eve. Faciitate the inspection of refractory condition, for exampe, by considering the use of sub panes in stee work to aow the inspection of refractory and anchors. If possibe determine the condition of the refractory in advance of the shutdown by the use of cameras or by deveoping predictive toos based on refractory samping. Insta access ports to aow instaation of the Pre-Heater Tower Safety Net. Increase research on the effects of aternative fues. Extra arge access doors Caciner ceaning hatches Panning & Design The recommendations contained within Kin Workshop Guide 1: Maintenance need to be considered aongside the foowing guidance. In particuar, participants on the 26th October 2012 reemphasised the importance of the eary Invovement of a parties (incuding designers, scaffoders, refractory wreckers and instaers) at the panning stage; the importance of one man in charge ; good communications incuding effective feedback; visibe management and supervision; good standards of housekeeping, identification of confined spaces (aong with suitabe permits and contros); and isoation procedures.

3 3 - Cement Pre Heater Tower Guideines Design: Every year requirements change and the change in design needs to be budgeted for. Improvements in computer software mean that pans can be tested before they are put into effect. Where required, there shoud be third party confirmation of the scaffod design and erection. Emergency Pans: There need to be effective emergency pans that incude the recovery of casuaties. Equipment and individuas need to be prepared, for exampe, to retrieve casuaties at height from the scaffoding. Diaing 999 does not constitute an effective pan. Scaffoding: Scaffoders need to be invoved at an eary stage as sites need to know what scaffoders require. Fittings etc. shoud not be stored outdoors due to the issue of corrosion. Storage of Materias: A suitabe safe area, with due regard for vehice and pedestrian segregation, shoud be provided for the storage of contractor toos, equipment and materias. The ocation of fire points and hydrants etc. shoud be considered when choosing this area. Safe Working Loads of Patforms; are a key issue and shoud be taken into account at the design stage, aong with the potentia for impact damage from wrecked materias. Reduction of materia buid up: Prior to the pant stop, as much buid up shoud be removed as practica, e.g. by manipuating process conditions. Safety standards shoud be maintained whether the work is panned or unpanned and as a genera principe the order of work shoud be as foows: Work from Top Down, Initia Externa Cean Insta Safety Net Fu Cean Down Re-Inspection Communication Contractors highighted good practice at EDF where each day/task started with a pre-job brief where the contractors were invoved in the pans and the method statements were gone through. This aso happened for the 12 hour pm shift. Meetings work best when a parties are invoved (incuding company interna departments e.g. eectrica and engineering - don t under estimate the potentia probems caused by ack of communication). The recommendations on co-ordination and communication contained within the Kin Workshop Guide 1: Maintenance shoud be considered. Scaffoding Genera access scaffods are covered under Genera access scaffods and adders HSE Construction Information Sheet No. 49. Scaffod design and checking is covered under BS5975: 2008 Code of practice for temporary works procedures and the permissibe stress design of fasework. This gives recommendations and guidance on the procedura contros to be appied to a aspects of temporary works, incuding scaffoding. The items to be considered in the design brief are covered in Section 8. Tabe 1 gives the foowing guidance on the checking of designs and possibe exampes have been provided by the scaffoding industry: Category 0 scaffod Scope - restricted to standard soutions ony Check - site design team Context - basic as defined in TG20:08 Possibe exampes: 0.1 Access towers muti ift with proper tie patterns Externa scaffods to a foors e.g. access to doors 0.2 Independents muti ift with proper tie patterns as above but onger scaffods e.g. for ducting. 0.3 Birdcages ight duty muti ift with proper tie patterns e.g. access for inspection to beam. Category 1 scaffod Scope - simpe designs with simpe anaysis methods ony needed. Check - site design team Context - simpe bridges with beams, simpe oading bays founded on the ground, edge protection made from scaffod components. Possibe exampes: 1.1 Bridge sections with beams not exceeding 6m span e.g. to span over push foor cooer pates 1.2 Loading bays based out at ground eve Externa scaffods outside doors to oad sma items of equipment / pant onto or sma amounts of refractory bricks onto. 1.3 Edge protection around hoes, voids, doors, roof-ights to restrict access to certain areas 1.4 Scaffods buit on top of roofs - shoud ensure sign off before work erected to confirm roof can take the oad to be imposed on it 1.5 Scaffods that are sheeted for dust containment, weather protection 1.6 Hanging scaffods (sma)- simpe 1 ift inspection hangar scaffod e.g. in Riser

4 4 - Cement Pre Heater Tower Guideines Category 2 scaffod Scope - more compex or individua designs with a considerabe degree of interpretation of oads/performance. Check - by an individua not invoved in the design and not consuted by the designer. Can be from the same or different organisation. Context - pubic protection, compicated bridging arrangements, heaviy oaded birdcages, scaffods for vehicuar access. Network Rai, London Underground and Highways Agency scaffods wi usuay be either Cat 2 or 3 due to the increased risk of interaction with the pubic, even if simpe scaffods. Possibe exampes: 2.1 Temporary roofs 2.2 Cantiever scaffods e.g. to extend existing scaffod over a void or a vesse 2.3 Large beam section over 6m span Most major internas e.g. in Caciner and Cycones 2.4 Heavy duty oading bays for oading motors or gear boxes onto the weight of the oad must be pre-specified so the oading bay can be buit accordingy 2.5 Scaffod where tie patterns cannot be met (buttresskentedge) e.g. free standing scaffod for roof access 2.6 Truss out e.g. out of window in pre-heater buiding for concrete repairs 2.7 Hanging scaffods (Large) Most major internas throughout the system 2.8 Protective fan e.g. over door entrances, pedestrian wakways. 2.9 Network rai scaffods Category 3 scaffod Scope - compex or innovative designs, compex sequences of moving/construction, considerabe exercise of engineering judgement. Check - by another organisation. Context - cose proximity to working rai ines, scaffoding for structura support/shoring, access for the pubic. Possibe exampes: 3.1 Fase work scaffod 3.2 Muti beamed areas 3.3 Compex or innovative designs 3.4 Considerabe exercise of engineering judgement A design check certificate shoud be produced for a categories, confirming that the design compies with a aspects of the design brief, the standards used and the oading conditions. HSE s understanding and interpretation of temporary works management can be found in the inspectors guidance note: SIM 02/2010/04 constrct/2_10_04.htm HSE have aso prepared a checkist to carify when scaffod design is required and what eve of training and competence those erecting, dismanting, atering, inspecting and supervising scaffoding operations are expected to have obtained. Design and inspection issues (HSE Checkist) Uness a scaffod is a basic configuration described in recognised guidance e.g. NASC Technica Guidance TG20 for tube and fitting scaffods or manufacturers guidance for system scaffods, the scaffod shoud be designed by cacuation, by a competent person, to ensure it wi have adequate strength and stabiity. A scaffoding shoud be erected, dismanted and atered in accordance with either NASC guidance document SG4 for tube and fitting scaffods or the manufacturers erection guide for system scaffods. For scaffods that fa outside the scope of Basic Scaffods as described in buet point 1 (above), the design information shoud describe the sequence and methods to be adopted when erecting, dismanting and atering the scaffod, if this is not covered by pubished guidance as detaied in buet point 2 (above). Any proposed modifications or aterations outside a generay recognised standard configuration shoud be designed by a competent person. Handover certificates shoud refer to reevant drawings, permitted working patform oadings and any specific restrictions on use. A scaffoding inspection shoud be carried out by a competent person whose combination of knowedge, training and experience is appropriate for the type and compexity of the scaffod he is inspecting. Competence may have been assessed under The Construction Industry Scaffoders Registration Scheme (CISRS) or an individua may be suitaby experienced in scaffoding work and have received additiona training under a recognised manufacturer/suppier scheme for the specific configuration he is inspecting. A non-scaffoder who has attended a suitabe scaffod inspection course and has the necessary background experience woud be considered competent to inspect a basic scaffod (ie a Site Manager). The scaffod inspection report shoud note any defects and corrective actions taken, even when those actions are taken prompty as this assists with the identification of any recurring probems. To prevent use by unauthorised persons of incompete scaffods, reevant warning signs identifying the areas where

5 5 - Cement Pre Heater Tower Guideines access is not permitted shoud be dispayed at the access points to these areas. In addition, access to the incompete areas shoud be prevented by suitabe physica means. Competence and supervision issues (HSE Checkist) A empoyees shoud be competent (or in the case of trainees, supervised by a competent person) for the type of scaffoding work they are undertaking and shoud have received appropriate training reevant to the type and form of scaffoding they are working on. Empoyers must provide appropriate eves of supervision taking into account the compexity of the work and the eves of training and competence of the scaffoders invoved. As a minimum requirement, every scaffod gang shoud contain an appropriatey quaified scaffoder for the type and compexity of the scaffod to be erected, atered or dismanted. This may be an individua who has received training under an industry recognised training scheme, e.g. CISRS, and has been awarded the scaffoder card or someone who has received training under a recognised manufacturer/suppier scheme, to the imit of the configuration(s) invoved. Trainee scaffoders shoud aways work under the direct supervision of a quaified scaffoder (i.e. a Working Foreman). Scaffoders are cassed as trainees unti they have competed the approved training and assessment required to be deemed quaified. 3.2 Initia Inspection The initia inspection of a areas shoud be carried out from an externa safe point foowing the cooing down period of the system. Ony competent and experienced personne shoud carry out the inspection. 3.3 PRE-HEATER TOWER SAFETY NET The Pre-Heater Tower Safety Net shoud be instaed before anyone enters the cycone of the pre-heater tower. Hanson Safety Net As part of Hanson Cement s 2012 Zero Harm objectives, the engineering department came up with a netting system, instaed at the start of the shutdown, to retain the roof refractory. Working with a eading UK netting company Huck Tec Ltd ( co.uk/) the origina ideas were turned into a working design which prevents any cycone roof materia faing onto peope during maintenance. Erection, ateration and dismanting of compex designed scaffoding (e.g. suspended scaffods, shoring, temporary roofs etc.) shoud be done under the direct supervision of a competent person. This may be a quaified Advanced Scaffoder, a Design Engineer providing they possess the necessary industry experience or aternativey an individua who has received training under a recognised manufacturer/ suppier scheme to the imit of the configuration(s) invoved. 3. INSPECTION AND CLEAN DOWN As with a working, operations during inspections and ceaning shoud foow the hierarchy of contro. The aim shoud be to eiminate risk by externa working where possibe and where entry to the pre-heater is necessary to introduce procedures to stricty contro any residua risk. Figure 1: Cycone roof with partiay wrecked refractory How it Works: Ropes are dropped through access ports in the roof of the cycone 3.1 Pre-Initia Inspection Cean down A pre-inspection cean down of cycones, riser ducts and bars shoud be undertaken externay using air ance/water basters/cardox/gyro whips etc.

6 6 - Cement Pre Heater Tower Guideines The ropes are then hooked and dragged through access doors The ropes are pued out through the cycone roof, disconnected and the tensioning rods are fitted through the brackets and tensioned. The ropes are then connected to the net on the outside of the cycone The nets are tensioned and pued up tight to the underside of the roof and the refractory roof is restrained. The connected net is then fed back into the cycone through the access door The net mesh size is 100mm and the gap between the net sections is 50mm. The net can restrain 5 tonnes and there is aso an option to fit side netting if required. It is beieved that the provision of port hoes in brick ined cycones shoud not be an insurmountabe probem. CEMEX DEVELOPMENT The connected net is then pued up to the underside of the roof During the annua maintenance project at CEMEX s Rugby works, the safety net was modified to suit their purposes; so that the individua net sections were stitched together and a fine mesh inner net was incorporated to catch smaer debris.

7 7 - Cement Pre Heater Tower Guideines Recommendation Design changes shoud be put in pace to accommodate the use of the net. 3.4 Cean down Or And Permit to Work must say its safe to enter. The cean down shoud be achieved by: Use of air ances/ bars/high pressure water through poke hoe doors etc (i.e. remove as much buid up as possibe using an externa method). Buid scaffoding access to cean down areas and undertaking ceaning. By provision of Bosun s chair access to cean down areas. Access to the kin shoud be prevented when the pre-heater is being ceaned down. The issue of akai burns must be addressed through risk assessment, safe working procedures and inductions. Best Practice: Access foowing externa cean down A Senior Manager (Works Manager or Production Manager) shoud authorize the first entry into high risk areas e.g. kins/ cycones/riser area where there is a potentia for a materias fa. This shoud be preferabe done in writing. Consideration shoud be given to repeating the procedure when conditions change, for exampe temperature, materia contraction or when unexpected conditions arise. 3.5 Re-inspections Knowedge, understanding and expertise are required, due to the dynamic situation created by the cooing process; and efforts need to be made to check the anchorage of the monoith. New she designs and the use of brickwork at Hope works have faciitated the samping and overview of anchor points. A re-inspection shoud be carried out after the cean down by a competent person. Further re-inspections shoud be carried out on a frequent basis (at east daiy). Inspect inings and anchor integrity by: Inspection ports. Considering the use of Refractory te tae devices. Visuay foowing access scaffod erection. Isoate feed pipes to cycones. Insert pate bades. Best practice is the use of pneumatic vaves. Erection of scaffod access to be undertaken by competent persons. Re-inspect reguary and whenever conditions change (this incudes the night shift). 4. WRECKING OF LINING Subject to the constraints of pant ayout and geometry; sites need to work cosey with wrecking companies to faciitate the use of automatic wrecking techniques, where possibe. Aong with faing refractory, one of the most critica safety issues during pre-heater tower working is ensuring that working patforms do not become overoaded. Scaffod patform The scaffod patform shoud be suitabe for wrecking operations i.e. fit for purpose regarding access to wrecking areas (i.e. no over-reaching) and with an appropriate oad bearing specification. Norma scaffoding inspection regimes shoud be stepped up due to the increased potentia for impact damage on scaffod boards. Protection scaffods shoud be used as standard (segregation scaffod patforms with mattress and edges cosed for exampe by use of profie boards, sandbags, expandabe foam and sheeting). Doube netting shoud be provided on hand rais from Bottom to Top. Wrecked materia must be reguary ceared for safe access/ egress and to avoid overoading of scaffod structure. MAKE IT EASY TO REMOVE WASTE (e.g. by providing conveyors/tracked dumpers). Ideay the route for waste shoud be out of the preheater tower and then down. Loading of patforms needs to be constanty poiced and awareness of the dangers posed by overoading shoud be raised through too box taks, Safe Working Practices, Risk Assessments and Method Statements. Simpe information on oading (e.g. what does a tonne ook ike) and the requirement to spread the oad across patforms needs to be provided to wreckers. A reguar inspection regime shoud be introduced and a new Inspection/assessment shoud be carried out after every incident (e.g. when the scaffod has been struck by faing materia). Make this a visibe fet eadership focus

8 8 - Cement Pre Heater Tower Guideines Wrecking of areas Other Wrecking to be carried out by competent person(s). Provide separate access for services (hoses etc.) and peope. Toos and equipment must be in serviceabe condition. Hose and whip checks are mandatory. Utiise mechanica wrecking where reasonaby practicabe. Minimise hand wrecking/use of vibration equipment. Rotation of peope wrecking to minimise exposure. PPE shoud be appropriate to the task and its use shoud be enforced. Work top down on wrecking process. Wrecking team to incude watcher observing any change in other areas oose materias. Isoate wrecked areas from continuing work to aow different tasks to be carried out independenty. There shoud be no overhead working without segregation/protection. Be aware of hazards created by the wrecking process for exampe, the exposure of od anchors (protruding stee). Issues raised by jack hammering of monoithics e.g. noise, dust, hand arm vibration and PPE shoud be covered by the risk assessment and method statement. Refractory instaers shoud be subject to reguar safety audits/ inspections. RECOMMENDATIONS Cients to review quaity contro procedures to ensure that product quaity and the quaity of instaation are adequatey covered. This shoud incude: The competence of instaers (incuding instaers of anchors). The specification for anchors (consider the use of 330 stainess anchors or ceramic anchors: and anchors with pate attachments). The quaity of anchor instaation. Product quaity (e.g. are materias eft over from the previous year s work in date?). Consider issuing radios to refractory supervisors. Use a safe container such as a gavanized bucket for transporting anchors (they are suppied in Hessian sacks which often have hoes in them as they have been dragged due to their weight. The anchors weigh 2 to 3 b and poke through the sack, they can aso fa out). Hoding daiy information meetings between cient and instaer woud be advantageous to a. Promotion of a chaenge cuture by instaers to prevent unsafe acts and conditions. Hod pre/post instaation site inspections to maintain housekeeping. 6. NEAR MISS/HITS Provide protection against weding fash for others working in the vicinity of weding activities. Provide protection against weding fumes. (Forced air hemets are now seen as best practice for weders). Provide oca exhaust for weding fumes (aso a consideration for refractory product spraying activities). Reporting The norma rues for successfu near hit reporting need to be foowed to encourage contractors to submit near hit reports, and sites need to ead by exampe, e.g. by maintaining high standards of housekeeping. 5. REFRACTORY INSTALLATION Refractory instaers/designers shoud be invoved eary in the in the panning stage and quaity contro procedures shoud be improved. Aternative fues wi have an effect on the design and refractory products used. Refractory manufacturers are coming up with improved materias and cients wi have to consider the various merits of increased use of pre-cast bock, brick versus monoith; more Shotcrete appications: and work with them to deveop robotic monoithic instaation techniques. Site Managers shoud wecome the reporting of near hits as a vauabe too in preventing injury. Contractors shoud be encouraged to report near hits and they shoud be treated in the same manner as empoyees. Where no discipine guarantees are in operation for empoyees who report near misses, consider extending them to contractors. The norma rues of successfu near hit reporting schemes shoud be foowed: keep it simpe, make it easy to report incidents, do not hod reports against contractor, ensure prompt action is taken, and provide feedback on the action that was taken. If necessary, open up confidentia whiste bowing hotines to contractors.

9 9 - Cement Pre Heater Tower Guideines Occupationa heath Refractory instaers shoud be introducing occupationa heath monitoring on a risk based approach. i.e. exposure to manua handing, noise, dust, hand arm vibration, fumes etc. Consider PPE such as metatarsa protection on boots. Participate in daiy pre-work briefs on heath effects. 7. LONGER TERM Discaimer MPA Cement has prepared this document in the interests of promoting a high standard of safety awareness in its industry. Compiance with any guidance set out in this document does not absove the user from his ega duties under the Heath and Safety at Work etc Act 1974 to form his own site specific assessment of his workpaces and operations and to provide accordingy for such matters. Whist MPA Cement has taken a reasonabe care in preparing its guidance neither MPA Cement nor its members wi accept any iabiity in reation to the guidance. Readers are reminded that egisation, officia guidance and best industry practice are a subject to change over time. This document was ast revised on 25th June In the onger term, the design of pre-heater tower vesses needs to change to faciitate safer ways of working. Managers need to start chaenging why anyone needs to enter under refractory. Innovation: Panning and execution. 3D modeing can be used to demonstrate that designs work. Consider redesign of vesses to faciitate new ways of working (exampes exist in the gas and power industries where demountabe roofs have been designed that aow for an access patform with a protective roof to be owered in). Where economics are dictating make it ast, more effort needs to be made with respect to refractory samping to determine condition and to buid up a record of performance (e.g. so that the effects of aternative fues can be predicted). Samping existing refractory annuay wi give a history of condition and coud be used as a predictive too to decide on ife of product and repacement. This coud be seen as simiar to condition monitoring. Other methods such as utrasound and therma imaging shoud be expored in determining refractory condition. Consider the use of remote cameras to identify probem areas to faciitate advance panning. Consider new methods of remote working, for exampe, emergency short term repairs are being carried out remotey on bast furnaces to get the pant through to the panned shutdown. MPA Cement is part of the Minera Products Association, the trade association for the aggregates, asphat, cement, concrete, dimension stone, ime, mortar and siica sand industries. MPA Cement members are CEMEX UK, Hanson Cement, Lafarge Cement UK and Tarmac Buxton Lime & Cement MPA Cement Giingham Street, London SW1V 1HU Te Fax info@mineraproducts.org Minera Products Association 2013