TECHNICAL SPECIFICATION FOR SOLUTION HEATTREATMENT FURNACE Nomenclature: Solution Heat treatment furnace for Aluminum alloys. Sr. Technical Details No. 1.0 DESCRIPTION: Electrically heated, forced air circulation & vertical drop type solution treatment furnace for 84mm Carl. Gustav Components as per Component drawing enclosed. Quantity per batch - 300nos minimum. Weight of the component 0.5kg approx. 2.0 Scope: Design, manufacture, supply, assembly, erection, commissioning of the furnace to its design parameters, capacity & rated out put. 3.0 SEQUENCE OF OPERATION: The following sequence of operation will have to be followed for Charging / Discharging of charging Stand/Tray. 3.1 One loaded charging stand/tray is placed on the trolley at the charging station with the help of hoist. 3.2 The trolley is pushed and brought underneath the furnace lid. 3.3 The furnace lid is lowered and each half is removed away horizontally to two sides. 3.4 The charging stand is hooked with the charge hoisting chain/ rope manually by the furnace operator and lifted in to the furnace. 3.5 The furnace lid is closed and furnace is switched ON. 3.6 The charging trolley is moved to the charging station. 3.7 After completion of heat treatment cycle, the furnace lid is lowered and each half is moving away horizontally to two sides. 3.8 Charging stand/tray is lowered down into the quench tank with the help of charge hoisting/lowering devices. 3.9 The lid should be closed after the charge is removed from the furnace. 3.10 After completion of quenching, the charging stand/tray is raised. 3.11 The trolley is pushed underneath the furnace lid. 3.12 The charging stand/trolley hoisting chain/rope is released and the trolley with the charge is moved back to the charging and discharging station. The above sequence should be repeated for second charge. Firm has to confirm that quenching operation should be completed with in 15 seconds with the system as proposed above. Varying speed of rope/chain should be achieved by variable frequency drive. 3.13 The above cycle should be able to be fed through SCADA system consisting of software, with branded PC of Pentium Core Two Duo processor of minimum 1GB Ram. Further in event of failure of SCADA the whole furnace should also be operated through manual setting on the display panel. 4.0 DESIGN PARAMETERS: 4.1 Maximum furnace temperature: 700 degree centigrade. 4.2 Working Temperature: 500-600 degree centigrade 4.3 Furnace Dimensions: 4.3.1 Diameter: Firm to design in respect of capacity mentioned in clause no.1.0 and same to be mentioned in technical offer. 4.3.2 Depth: Firm to design in respect of capacity mentioned in clause no.1.0 and same to be mentioned in technical offer. 4.3.3 Temperature variation with in the furnace: + / - 2.5 degree centigrade. 4.3.4 Variation of temperature in furnace chamber: Steady state soaking condition, with in 5 degree centigrade. 4.4 RATING: Firm to design in respect of maximum power efficiency and capacity mentioned in clause no.1.0 and same to be mentioned in technical offer. 4.5 RATE OF HEATING: Rate of temperature rise should be 250 0 C per hour from ambient
temperature when furnace is in no load condition. Suitable rating should be provided based on heating the charge load of about 200kg in addition to charging stand whose weight is approx. 200kg from ambient to 550 degree centigrade. The average soaking period will be 30 minutes after furnace reaches a study state temperature i.e. 550 degree centigrade. 4.6 FURNACE CONSTRUCTION: The furnace should be double chamber construction, one chamber used as a working chamber and the other chamber to accommodate heater unit. The furnace casing of working chamber would be in the form of double cased construction, the outer casing being constructed from mild steel sheet of minimum 6mm and the inner sheet would be constructed from stainless steel (SS310) sheet of minimum 3mm thickness. The space in between the outer and inner casing should be filled with thick insulation of appropriate density to reduce heat losses to minimum. With the insulation of ceramic blanket & insulating bricks, the skin temperature should not exceeds 20 degree centigrade above ambient temperature. The heater chamber should be adjacent to working chamber. The individual heating element of heater chamber should be easily replaceable from top side of the heating chamber for easy maintenance. Hot air ductwork should be provided for effective circulation. The whole furnace should be rest on a raised platform to accommodate the charging trolley underneath the furnace. 4.6.1 HEATING ELEMENT: Heating element should do the heating of air for recirculation, located outside the working chamber but in the recirculation air path. This should consist of vertically mounted Bayonet type Kanthal A1 / strip type Nichrome 80:20 heating elements with surface load not exceeding 1.5 to 2 watts/square centimeter. Firm to submit the required documents to prove the same. Composition of element and its size and watt density should be specifically mentioned in technical offer. 4.6.2 THERMO COUPLE: Duplex K type thermocouples should be supplied along with complete mounting arrangements at various positions for indicating the temperature of furnace zones and furnace charge. Renowned make with necessary compensating lead wires to be provided. The distance between the two thermocouples should be with in one meter. 4.6.3 RECIRCULATION FAN: To provide the necessary air for recirculation, a high capacity plug type centrifugal flow fan should be provided, which should be complete with electric motor, starter and V-belt drive. Recirculation fan should be fabricated in SS 304, with minimum 10 HP motor. 4.6.4 RECIRCULATION DUCTING: Recirculation ducting made of stainless steel grade AISI 310, 3mm thick should be provided. Material used for the construction of fan impeller, shaft are heatresisting steel grade AISI 310 to withstand the temperature and duty conditions. 4.6.5 FURNACE LID: The furnace should be provided with one lid split in to two halves mounted at the bottom of the furnace and should be of horizontal sliding type. Horizontal sliding motion of the door would be achieved Pneumatically & Mechanically. The sealing of the door would be achieved by Pneumatic & Mechanical operated clamps. Limit switch would be mounted such that when the furnace lid is opened, recirculation fan stops. Door should remain in closed position in case of power failure & pressure drop. Furnace lid to be lined with ceramic blanket & backed with Rock wool insulation. 4.6.6 FURNACE REFRACTORY: To be Quoted by firm in view of the skin temperature. Firm to ensure the skin temperature of the furnace should not exceed 20 0 C above the ambient temperature. Material come in contact with heating element should have Fe 2 O 3 content below 0.5% and for same suitable test certificate to be provided by firm. Firm to specify the details of refractory material used and its thickness for furnace and furnace lid in technical bid. 5.0 AUXILIARIES COMPULSORY REQUIRED ALONG WITH FURNACE: 5.1 Charge loading trolley: To facilitate charging of charging stand/tray into the furnace and removal of quenched charging stand/tray from the quench tank, one trolley mounted on rails should be provided. The trolley should be located immediately below the furnace lid but above quench tank. The trolley should be operated with electric motor between the charge loading/unloading station and below the furnace lid.
5.2 Charge hoist rope/ chain: Lifting of charging stand/tray from the trolley into the furnace and lowering from the furnace into the quench tank should be achieved by an electromechanical drive. Chain should be of SS 304 material to withstand furnace temperature. 5.3 Charging stand/ tray: Charging stand/tray should be designed for easy loading and unloading component and no scratches should be projected on the components while loading, quenching and unloading. The charging stand should be manufactured from stainless steel to specification AISI. 304. Design of the charging stand/tray should be circular tier type with central stem. Firm should provide one set with furnace & one set additional. 5.4 WATER QUENCHING TANK: 5.4.1 Construction: To quench the charge, after heat treatment, a square type water quench tank made of stainless steel plate of minimum 8mm thickness with suitable surrounding reinforcement to be provided. The tank size should be designed by firm. There should be Out flow openings at the top of the tank with filter nets, connected to a collector. The quench tank should be located in a pit below the furnace lid. The pit should be located below the ground level. Capacity of the tank, inlet and out let water flow should be designed such that the quenching water temperature is always maintain between 25-30 degree centigrade 5.4.2 Agitation Pump: To provide necessary agitation of quenching water, water pump of adequate capacity should be provided. The inlet to this pump should be taken from the bottom of collector mentioned above. The delivery of water from the pump is done at the side of the quench tank and nearer to the tank bottom. All pumps & motors should be mounted on ground floor for easy maintenance. One additional pump for dewatering of tank should be provided. 5.4.3 Water Pipe Work: All necessary water pipe connections to the quench tank from the abovementioned point should be done by supplier. If cooling tower is required to maintain the quenching water temperature between 25 to 30 degree centigrade, it should be part of the supply. 6.0 INSTRUMENTATION / ELECTRICAL PANEL: 6.1 The Control panel should be made out of 16 B.G. CRCA sheet, factory finished and painted with powder coated paint of gray color and should be designed as per I.P.55 protection and mounted one foot above ground level. 6.2 The control panel should have one incoming switch of adequate capacity as per plant requirement and should be SIEMENS/ SCHNIDER/ G.E/ L&T make only for switching the panel. 6.3 The plant should be controlled through PLC system of SIEMENS/ ALLEN BRADLEY/ MITSUBISHI make only. The PLC programming should be such that tracing of fault is very easy, maintenance friendly by giving alarm listing for each and every fault possibility complete in all respects. 6.4 Digital Profile temperature controller with 4 ram & 4 soak to be provided. It should be of Eurotherm/ Honeywell/ Maxthermo/Taie make. 6.5 For recording the process temperature Six point graphic recorder to be provided. Paperless recorder which produces real time display, stores data on a flash memory card and sends data via Ethernet to a remote PC for real time monitoring and display. It should be made of Eurotherm / Chino / Honeywell/ Brainchild. 6.6 All panel meter such as Ammeter, Voltmeter, Power meter, Energy meter etc. should be supplied only digital type of TOSNIWAL/ AE/ L&T/ RISHAB make only with suitable selector switch. 6.7 All indicating & controlling equipment should be nicely mounted on the front position of the control panel. The indicating equipment should be such that at a glance one can understand the status of the plant. The hardware should be Teknic/Schneider/Siemens make only. 6.8 The power & control wiring should be done through copper cables of suitable size up to junction box close to furnace. From the junction box to all equipment mounted over furnace, it should be made of fibre glass insulated flexible stranded copper conductor wire of fire proof with adequate capacity.
6.9 The complete design of control panel should be simple & easy as per maintenance point of view. 6.10 Hard copy of PLC programming & Original software of PLC and SCADA should be given along with electrical circuit diagram. Back up of PLC program in CD. 6.11 Control panel having provision of switches to perform all operations in manual in case of PLC failure. 6.12 All motors will be provided with thermal over load relays 6.13 Over temperature controller will switch OFF the heating element in case of failure of main controller. 6.14 Emergency shut OFF switch with indicator to be provided. 6.15 An audiovisual Alarm system is required on panel top for indicating the fault condition viz. over temperature, motor failure, no water circulation for running motors and for cycle completion. 6.16 Overload safety should be provided for electrical system. 6.17 One energy meter to monitor the power consumption to be supplied. 6.18 All motors supplied should be made of SIEMENS/ CG/ ABB/ BHARAT BIJILI / KIRLOSKAR 6.19 All items being brought out for the construction of the plant should be disclosed with the full address & telephone numbers so that the requirement of the same can be purchased/technical discussion can be had directly with those sources. 6.20 Temperature recorder: To record temperature in working chamber, one 6 point paperless chart recorder to be provided with necessary thermocouples and required long compensating cable is to be included. Make of recorder should be Eurotherm/ Honeywell / Brainchild / Chino. 6.21 Temperature control: Temperature Controller is to be done with the help of Thyristor drive with separate PID controller for further retransmitting output for PLC in put, to achieve +/-2.5 degree celsius with a digital temperature display on the control deck of the furnace as well as on SCADA system monitor. SCADA system to be provided to record & store temperature as per Batch No. for a period of 6 months. The system should be capable of showing a Graph of temperature with respect to time for particular Lot No. Temperature setting should be provided in both systems in automatic as well as in manual modes. The SCADA system will be installed at about 100 meter from the furnace. Three position (Top, middle and bottom) sensors along with controller of digital display type work in conjunction with suitable thermocouple, with desired length of compensating cable to be provided. Thyristor drive should be of Eurotherm /ABB / Danfoss/ Honeywell make. Over temperature cut off contractor should be provided in each zone to safe guard the furnace against short circuit of thyristor. 6.22 Quenching water temperature indicator is to be provided. 7.0 SAFETY FEATURES: 7.1 Over temperature safety: To provide safety against over temperature, an indicating controller with thermocouple should be provided with alarm indication. 7.2 Fan failure safety: One pressure switch is included in the air path of heater chamber to switch OFF heater unit in the event of fan failure. 8.00 SPARES REQUIRED: Following spares should be supplied essentially along with furnace. Two sets of Thermocouples, one number thyristor drive, two sets of over temperature controllers and indicators, 10 numbers of thyristor fuses, two sets limit switches (for door and for chain), two sets of all type of sensors and over load relays and contactors used in furnace, two sets of out put relay cards, and 2 nos. of emergency switches. One set of heating elements for each zone. One set of mechanical spares i.e bearings, fan impellers, gear boxes etc. to be supplied along with furnace. And spares to be supplied along with furnace to run the furnace trouble free for a period of 2 years based on 2shifts X 8 hrs. Details of the spare parts and its source list are to be given to OFA. Components/ items used in furnace should be available in market for next ten years.
9.00 GENERAL FEATURES: 9.1 TRAINING: The supplier shall impart necessary training to the purchaser's personnel for proper operation and maintenance of the plant. 9.2 TECHNICAL LITERATURE: The supplier shall provide illustrations, pictures, drawings, product catalogues with his offer to provide general idea of the product being offered. 9.3 INSTRUCTION MANUAL : Operation Manual - 4 sets, Maintenance Manual-4 sets complete with Electrical Circuit drawings, Spare parts Manual - 4 sets & trouble shooting manuals, and Manuals of original equipment suppliers for the bought out items shall also be supplied (in English Language). In addition to the above manuals firm should supply the data of spare part list, trouble shooting procedure, list of consumables, fast wearing parts. All warranty documents of items used in furnace should be hand over to OFA after commissioning. 9.4 SPACE REQUIREMENT: Firm should submit G.A. drawing showing complete furnace overall dimensions, materials, charging stand/tray design, quenching tank etc. with the tender to study the working of the offered furnace. Furnace height should not exceed 6300mm. 9.5 Approved G.A drawing and Foundation drawing should be submitted by firm with in 30days from placement of Purchase order. 9.6 Civil foundation work will be carried out by the purchaser (OFA) as per supplier's foundation drawing. 9.7 Supplier shall undertake to unload and shift the consignment to the storage area and erection site in case a single consignment weighs more than 5 Metric Tons. In all other cases the purchaser (OFA) shall provide / facilitate unloading of consignment at OFA on receipt under the vendor's supervision. 9.8 To ensure completeness of the equipment the supplier shall include in his scope of supply all auxiliary items like piping, interconnecting cables, other items which will be necessary for running of furnace for 3 months but are not included in this specification. 9.10 Supplier shall be responsible for safe delivery of entire consignment at consignee's site in good condition. 10.0 INSPECTION CRITERIA: 10.1 After placement of order, firm to visit the site before manufacturing the equipment. 10.2 Before manufacturing the equipment firm has to take drawing approval from the OFA. The drawing will consists of all details of material, dimensions, type of bearings used, type of gear boxes used etc. 10.3 Firm has to offer two stage inspection of the equipment. One is during manufacturing the equipment and another is pre dispatch inspection. 10.4 PRE DISPATCH INSPECTION: Pre-dispatch inspection will be carried out by OFA PDI team by dry operation (with out heating) of the furnace at the firm's premises before clearing for dispatch of the equipment. OFA team will check the functioning of all equipments in cold run. Firm to show the related test documents for material conformity /make of all items used in the furnace and the test certificate must be from any NABL accreditated lab. 11.0 ERECTION & COMMISSIONING: It shall be the responsibility of the supplier to arrange for erection of the entire equipment and commission it satisfactorily to achieve the rated output, using their own tools/tackles, man and material etc. On successful commissioning of the equipment the supplier shall arrange to demonstrate the equipment for continuous operation at the rated output. The tenderer shall quote the charges for erection & commissioning separately and likely period for erection/ commissioning and other terms and conditions. Equipment unloading inside the shop will also be the responsibility of the supplier. 11.1 POWER SUPPLY: The power supply available is 440±10V, 50Hz, 3 phase AC. Any other voltage required shall be arranged through inbuilt transformer by the vendor to be installed in the control panel. 11.2 WATER SUPPLY: Normal water supply will be provided if required at the site. Temperature of
the water normally does not exceed 35 degrees centigrade. 11.3 COMPRESSED AIR: Compressed air is available up to a maximum pressure of 5 Kg/sq cm. 12.0 FINAL ACCEPTANCE TERMS: After successful erection of the furnace by the supplier, the furnace will be put to trial without and with load. The performance of the furnace will be observed during the trail for 21continuous working days (2 shifts X 8 hrs per day). Firm has to prove the furnace parameters to specification. Firm has to prove component hardness of 70 to 80 VPN after the solution heat treatment with OFA heat treatment cycle. After satisfactory completion of the trials, the furnace will be considered as commissioned. Operational controls and parameters of SCADA system should be proved during trials. 13.0 Warrantee / Guarantee: Guarantee for complete furnace and all supplied accessories/ equipments/items for 12 Months from the date of satisfactory commissioning of the equipment.