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HomeMy WebLinkAboutCBPR-4-11-10455 Plan Support Document.tif C- 4 PR - ' 4-11-10457-S 1 OF 8 James Lamb I From: Hoffmann Paul [Paul .Hoffmann @gknsintermetals.com] Sent: Thu, May 05, 2011 1:05 PM To: James Lamb Cc: Haines Marty; Pastirik Tom Subject: GKN Conover Permit support Attachments: GKN Sinter Metals Conover Air system support.doc; PLN - Permit Plan Review Notes.pdf Mr. Lamb, It was a pleasure talking with you yesterday and I appreciate your time and consideration in insuring the Conover installation is operationally safe and compliant. As discussed, there appeared to be some minor confusion of the parameters of the materials involved and the applicability of proper code. GKN utilized the consulting services of Chilworth Global in developing a full review of our powder operations, testing of materials and design of improvements. The relocation and upgrading of our baghouse serves to complete these recommendations. Chilworth is the renowned global expert in metal dusts and is the same firm Federal OHSA has contracted with for training in the subject. The Conover site produces high quality sintered aluminum products. The process utilizes a blended metal powder that basically consists of aluminum and copper in a 140 micron particle size. The particle size and shape plus the properties of copper cause this material to be rated as a low combustible /explosible dust in the ST01 range. Finer and purer aluminums have a reputation as much more hazardous material in the ST03 range. This is not our case. Still, the ST01 rating requires proper handling and warrants protective measures. Typical metal dust handling systems utilize ducting and baghouse design as per NFPA 484, 68 and 69. This is the case with our system. These measures include: • Baghouse vertical deflagration venting • Grounded and bonded systems • High cfm (4500)to prevent duct build up and maintain MEC levels below 25% • Heavy gauge duct with supports at 10 ft minimum • An explosion decoupler device at the baghouse feed to isolate a baghouse failure • Rotary air valve to insure isolation of collection • Grounded collector bags • Duct line Inspection ports • No dead -end taps in the duct system • Minimum length duct runs Further conversation with Chilworth in regards to your note regarding fire suppression (PLN note #8) confirmed that that type of protection is not used in metal dust applications due to it's inability to provide sufficient speed. Normally this applies to organic materials such as wood, food, etc. Metals follow NFPA code requirements for decoupler and deflagration instead. Our duct system sizing does not require deflagration of the internal system, but does require it for the baghouse. Both exterior deflagration and decoupling have been provided in our design. I have attached a copy of the pertinent portions of the Chilworth report which includes design recommendations, powder combustibility test results and applicable NFPA code. It is my hope that this information satisfies your concerns regarding fire suppression. I understand that the other listed remarks have been sufficiently addressed by our contractor and site representative. We appreciate your consideration in approving the permit to allow our completing the installation and further improving the safety of our existing operation. GKN Sinter Metals has a long history of safe and environmentally sound operation and we pride ourselves in being the global leader in powder metrology. Your efforts to assist us in insuring a safe and properly engineered design are appreciated and support our commitment to the safety of our team and the community. If there are any further questions, please do not hesitate to contact me. Best Regards, Paul Paul Hoffmann, CEI / CES 1 i G6PR— ' It -to45S z o� g Regional Director - Environmental. Health and Safety, Americas i GKN > Sinter Metals i Germantown, WI 0: 262 - 437 -3818 C: 262 - 844 -3707 F: 262 - 255 -3306 `j Please consider the environment before printing this email 2 ca PP. - 4-)1- 1 oLt5-S Ch i Iworth COM BUSIBLE DUST CLOUD EXPLOSION HAZARD ASSESSMENT AND CONTROL FOR THE GKN SINTER METALS COMPANY FACILITY AT CONOVER, NC TO: GKN Sinter Motels 407 Thomburg Drive Conover, NC 28613 FAO: Mr. Tom Pwbrik tha!,Fxo int&q-,ly of "nfomix,'on p-ovided iri ths rapnel,; &t'g,,x t,.Yd copy spa bo "�oozidW4:0 t1v "Obrro document :end any do,11 v Nnofls stkV , No conn;dorpd A Authored By Reviewed By Vladimir Slotsovsky Pleler Zoouwan Senior Process Safety SoodaNst SonW Procaw Safety Spodakst FOR AND ON BEHALF OF CHILWORTH TECHNOLOGY, INC. Report Number FV10478,*910 Date OS ,24MO Rovi sod 10111/10 CTI Ref GK11047&VS chdwrarm Tocftnotoev Inc j 6"T" 444s, T 8---o r 4'm4 (sio NJ 08636' i UI,ItQd SWEa-,4 vI A-e,.L. I www,c,hihNofth.com tv CI3PR- oth- 55 } 4. Central Dust Collector and Local Exhaust Ventilation: a 4.1. GKN should evaluate existing dust collector explosion venting and isolation Design based was on using latest dust expiosfvity data obtained from testing (see Table 1, sample these values "Rafters and Top Surfaces"). f 4.2. GKN should ensure that the dust collector fitter media are made from electrically- conductive material and are grounded. 4.3. Ventilation ducting air rates should be sufficient to ensure that a significant At 4500scfm, ducts are safety margin is provided by dilution of the expected dust load to a point below calculated to be below the Minimum Explosible Concentration, MEC, of the dust processed (250 20% of the MEC — no gaVm'). NFPA 69 recommends that, when fuel dilution is used as a Basis of further deflag or Safety, the fuel (dust) should be diluted below 25% of the MEC. suppression required 4.4. GKN should consider system- petfonmance monitoring to warn of less than adequate LEV. Such monitoring could include differential pressure across the dust collector and +or flog measurements or switches. Operations that could release an explosible dust should be curtailed when the LEV system is not adequate. Interlocks should be considered to prevent explosible dust generation when the LEV system is not functioning adequately. 4.5. A minimum conveying velocity of '1384 mlmin (4500 Wmin) should be abc maintained throughout the conveying system to prevent the accumulation of dust at any point and to pick up any dust or powder that can drop out during abc unscheduled system stoppages (requirement of NFPA 484, Article 4.1.9.8.4). 4.8. LEV intakes capture velocity should be sufficient to capture fugitive dust. American Council of Government and Industrial Hygienists (ACGIH) provides following guidance: C 6PZ- 4 -(I- (0455 S o f 8 k i Client: GKN 8lnter Metals Project, Combustible Dust Explosion Hazard Assessment Chilworth I Report W.: GWI0478&YS Data: 9v24MO Revised 10'11/10 GLOBAL X k i Table 4: Capture Velocities i DustlAir Scenario E impies Flecommencled Face Velocity Measured at the Capure Point t ) Face Low velocity dust Manual pouring of powder. Bag 100.20© release into still air and drum dumping velocities Dust release into Bag and drum filling operations. 200 -500 are above rapid air motion Tumble blending m 225E High velocity dust Grinding and milling operations, 500 -2,000 p release high-shear blendin 47. The ductwork dust collection system should be provided with adequate inspection and deanout ports, and routine inspections should be made to reduce the possibility of secondary dust explosions being transmitted through the ductwork. Such explosions can be extremely violent due to flame acceleration common in long transfer lines. 4.8. Chilworth understands that in the nearest future GKN intends to replace existing System oversized central dust collector with the new one, located much closer to the compacting as recommended presses. The proposed new dust collector for the LEV system should satisfy the and deflag vents requirements of NFPA 484, NFPA 88, and NFPA 89 for air- material separators and isolation used with combustible metal dusts. Minimum design requirement for the dust device provided collector deflagration venting and isolation should satisfy conditions for the ventingrisolation of the explosion of the dust described as 'Rafters and Top Surfaces" in the Table 1. However, in order to accommodate future process changes and new materials, GKN should consider installing deflagration vent and explosion isolation device of the biggest size can be fitted to the dust collector and ducting. Table 4 below summarizes NFPA 484 requirements for the aWmaterial separation devices (dust collectors) intended for aluminum - contained metal powders: or g PR — 4- 11- I o455 R Client: chi Ginter Metals Pra0a: Combuedb Duet 6tO*m Hazard Aseeenm nt Chilworth PAPW No.: 01004781VO Dow: 9 1O Revised MI 1010 Q t 8 O A t Tabb 5: Aluminum - Contained Dust Collection System Floqulremonts Summary Primary Applicable NFPA FPA 484 Type of Dust Dry Dust Collection Collector 1. durst collector needs to be exploslon•protacted. One or more of the following methods shalt be used: a. Equipment designed to contain the anticipated explosion In pressure, Special Salety b. Appropriately designed explosion venting per NFPA 6& compliance tlloasums for the Extreme care shall be taken in the selection of the type and Dust Collector location of verb or weak sections of the collector to minimize injury to personnel and blast damage to nearby equipment or structures. Deflagration verts shall be positioned so that a potential blast shall not be directed toward any combustible or frangible structure. a Explosion suppression system meeting the requirements of NFPA 69, Standard on Eq)kmbn Prevendan Systems d. inert gas used to reduce the mr pan content within the equipment to bellow the level prescribed by NFPA 69, Standard an Expfosion Rovanibn Systems 9. Dilution with a noncombustible dust to render the mbcture nomombustbie f. Oxidant concentration reduction In accordance with NFPA 69, Sltanalard on 6gpadion Pramnion Systems 2 Cyclone or crttuer dry-type cdledcrs shalt be equipped with instruments for roc acting the surface temperature. An overheating alarm or warring device shall be included, and the limit setting shall be below the maximum service temperature of the filter medium or 32'C (90"F) below the ignition temperature of the powder cloud, whichaver Is lower. The devices specified above shall give audible and visual alarms at normally attended locations. a Collector fitter modium mare from synthetic fabrics that accumulate static electric granges shat riot be used. 4. Dry -type cyclone dust collectors shat be located outside of buildings. Location and 5. Electrostatic and media collectors shall not be used. arrangement of a 6. The accumulation of material Inside any area of the cxotedor other dust collector than In the discharge containers defined for fit purpose shall not be permitted. 7. Accumulation or condensation of water at any point in the dry dust - collection system shat be prevented. B. The c:yclono dust collector shall be softmakled with smooth Internal seams. .>F g Client: QKN sinter Metals j Project: Combustible Dust EKplosian Hazard Assessment Chilworth Report W.: QKt10478Ns Dote: 9;2411 o Revised ICFI 1110 GLOBAL 8. The blower for drawing the dust -laden air into the collector shall be located on the cloan•air side of the collector. 14. The area around the collector shall be posted with a sign that reads as follows: CWTfON. TMs dust coNecta can contain expiosdo dust. In Recvdirm of Recycling of air from drydust collectors into buildings shall be compliance Exhaust Air prohibited. 1. All dust - collection systems shall be installed in accordance with NFPA 91, Standard for Exhaust Systwm for Air Cony ap of Vapors, Gases, Adds, and Nor combusible Partidd'ate Soft dcis 2. Ducts shall be designed to maintain a velocity of not less than 1365 Duct System m'min (4500 fUrnin) to ensure the transport of both coarse and fine particles and to ensure re- entrainment 0, for any reason, the particles can fall out before delivery to the collector (for example, in the (rent of powerfailure).Ducts shall be designed to handle a volumetric flow rate that maintains dust bads safety below the minimum explosible concentration (MEC). a Duds shall be constructed of conductive material and shall be carefully fabricated and assembled with smooth interior surfaces and with Iraornal lap joints facing the direction of airflow. 4. There shall be no unused capped outlets, pockets, or other deecl- end spaces that might allow accumulations of dust. a Duct seams shall be oriented in a direction away from personnel. Additional branch duds shall not be added to an edsting system without redesign of the system. rx Branch duds shall not be disconnected, and unused portions of the system shall not be blanked of without providing means to maintain required airflow. 7 Dud systems, dust collectors, and dust-producing machinery shall be bonded and grounded to minimize the accumulation of static electric charge. a Whenever a duct size changes, the cross - sectional area changes as well. This change in area causes a change in air velocity in the region of the change, introducing turbulence effects. The net result is that a transition with an included angle of more than 30 degrees represents a choke when the direction of flow is from large to small and results in localized heating and static electric charge accumulation. IN hen the transition is from small to large, the air velocity drop at the transition is usually enough to cause product accumulation at the transition and the existence of a volume where the concentration of combustible is above the MEC. It is strongly desirable to avdd bath of these situations. L(3P2- 4 O'A- g OF $ a Client: GKN Sint Duss Chilworth Project: Combustible Dust ExPlasion He m Hazard Aases�ent Report No.: QW1047&VS Date: W24110 Revised IM VIO a Lo B A L s Table 1: QKN Combustible Dust Properties s ! Property "Powder Bag Raw" "Reflors and Baghouso Surfaces" "Aluminum" Chihaorth Report Chilworth Reports Chilworth Report 10340 10341 and 10269 10344 Particle Size 150 pm (median) < 75 pm < 75 Nm Is Material Yes Yes Yes Combustible? Minimum Ignition N D > 500 > 500 Energy, MIE (mi) Minimum Dust layer Ignition Temperature, ND NID WD Note MITI, 4 C) baghouse MEC 2x Minimum Explosible dusting Concentration, NO 250 -300 450 -500 load duct MEC (g rn) MEC calculated Maximum Pressure, Prrnx (berg) NID 8 8.0 at less than 90 Maximum Rate of Pressure Rise, ND 319 183 (dPidQ., (barisec) Deflagration Index, Kw NID 87 50 (bar- misec) Is material conductive? Yes Yes WA NOW WD- not determined