Annexure -1 Technical Specification for Design, Manufacture and Supply of “Bell jar type High temperature heat treatment resistance furnace having all metal construction”

1. SCOPE Design, fabrication, supply, hot testing at manufacturer’s works, packing, delivery, installation and performance testing at user’s site of a resistance heated Bell type High Temperature all metal resistance heating Vacuum Furnace as per technical specifications.

2.DETAILED TECHNICAL SPECIFICATION The system shall consist of following major components/modules:  Furnace chamber with screw type motorized bell lifting mechanism  Lanthanated Molybdenum Heating element  All metal radiation shields  Vacuum System consisting of Rotary Vane pump.  Step down transformer  Control Panel mounted with various instruments like temperature controller, thyristor, safety controller, vacuum meters, PLC.  One set of forged/ mechanically drawn( machining route is not acceptable) tungsten charge carrier for loading the charge in the furnace

All interconnecting power, control and compensating cables between these modules are within the scope of supply. Distance between furnace and transformer shall be about three meters and the distance between furnace/transformer and control panel shall be 15metres.

2.1 High vacuum furnace Supply, hot testing at manufacturer’s works, packing, delivery, installation and performance testing at user’s site of a bell type, resistance heated high temperature high vacuum furnace installed inside a glove box made of SS-304 with 3mm thick of approximate dimension 2200 mm (length) x 1100 mm (breadth) x 1100 mm (height) as per schematic drawing shown in fig.1 & 2 and capable of continuous operation at 1800ºC at a vacuum of the range 10-3 mbar. It shall also be possible to operate the furnace in slight over pressure (50 – 100 mbar above atmosphere) under high purity inert and hydrogen atmosphere. The furnace shall have a cylindrical lanthanated molybdenum heating element and all metal radiation shields. The all metal radiation shields shall be made in layers. The thickness of every layer shall be 0.3 mm. The details of layers are given in subsequent section. The furnace shall have thyristor power control, PID

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programmer for temperature control and programmable logic controller (PLC) for implementing safety interlocks. The furnace is to be used for sintering of ceramic pellets. Dimensions of pellets and batch size are as follows:- Pellet size: 11-13 mm diameter, 15-18 mm height Batch size: 2.5 Kg Heating shall be done in inert/vacuum/hydrogen bearing atmosphere under slight over pressure (50 – 100 mbar) above atmospheric pressure. The size of the uniform hot zone shall be around 140 mm in diameter and 250 mm in height for multilayer loading of cylindrical pellets on a tungsten charge carrier. The tungsten charge carriers shall be manufactured via mechanical drawing route only. Tungsten trays manufactured via machining shall be rejected. The furnace chamber shall be fabricated with S.S. 304 L material. It shall be cylindrical in shape and double walled with water-cooling facility. Guiding baffles shall be placed inside the shell for effective water circulation. The inside and outside wall thickness shall be 6 mm and 4 mm respectively. Top of the chamber is welded with dished end and bottom of the bell jar is welded with flange. The flange thickness should be around 20 mm with a facility for positive lock with hinged clamps. The chamber shall be fabricated as per ASME Section VIII, Division I Standards. 100% radiography of all the welded joints shall be done and radiographs shall be made available at the time of inspection. The cooling water jacket shall be pressure tested by hydro test up to 5 kg/cm2. The whole chamber shall be leak tested with Helium leak detector with a sensitivity of 10-9 std.c.c./sec. The inside and outside surfaces of the chamber shall be electro-polished to bright finish.

Lifting of the bell jar shall be by means of motorized mechanism consisting of linear guide & bush, Ball Screw arrangement for jerk free lifting arrangement maintaining the leak tightness of the glove-box. The furnace chamber and lifting mechanism shall be located in such a way that sufficient space would be available all around in the glove box for various operations such as loading and unloading of charge, removing/changing of heating element and radiation shields, thermocouple, etc. It shall be possible to lift the bell for a convenient working height and turn it by 90º and lock it in that position. The lifting motor should be fixed below the glove box through rotary seal. The drive shall be taken outside Glove box through a rotary oil seal. Provision for hand cranking of the bell jar should also be provided. Final inspection will be carried out with furnace fully installed inside the glove box.

The double walled furnace chamber shall be cooled by water circulation. The maximum rise in skin temperature shall be restricted to about 15ºC above ambient at the highest operating temperature of 1800 ºC. The cooling water circuit shall include flow switches, ball valves and outlet water temperature indicator. Digital indicator with thermocouple should be provided to measure the outlet water temperature in the cooling lines. All feed throughs and O-ring seals Page 2 of 14

shall be adequately cooled for protection. Water cooling to electrodes and conductors should be so designed to avoid accidental ingress of cooling water into the furnace chamber. It shall be ensured in the proposed design that in no case water enters the hot zone or below hot zone inside glove box. Hence water leakage into the furnace chamber should be entirely avoided.

Heating element will be in cylindrical shape and made of Lanthanated molybdenum suitable for 1800 ºC. Insulation shields shall be made of all metal. Inner 3 layers of 0.3mm thick tungsten followed by 2 layers of Lanthanated molybdenum of 0.3mm thick each followed by SS layer in the outer most ring.

Two no. of thermocouple made of Tungsten-3% Rhenium / Tungsten-25% Rhenium with suitable insulation to withstand operating temperatures shall be provided. The design of the thermocouple insertion arrangement shall be such that, the thermocouple can be changed very easily inside glove box.

2.1.1 Brief specification of glove box: Glove box made of SS-304 with 3mm thick of approximate dimension 1200 mm (length) x 1200 mm (breadth) x 1200 mm (height) as per schematic drawing shown in fig-1.

Material of Construction: a) Material Identification: Bidder shall submit mill test report (for chemical and physical properties) in co-relation with the material marking. b) Glove Box: The glove box frame shall be made from ASTM A 240, Type 304 S.S. sheets, not less than 3 mm thickness. c) S.S. Bright bars : Bright bars to be welded to the S.S. frame shall be bright drawn rectangular flats, size 15 x 13 mm of quality conforming to ANSI 304. d) Hardware: For fastening the panels high quality zinc-plated (galvanized) M.S. socket-head screws. All other nuts, bolts, washers etc. shall be of conventional materials subject to our approval. e) Panel size: Metallic panel with viewing windows and four glove ports on two sides per panel other two sides shall be provided with SS 304 blind panel with 10’’ provision of Bag in/Bag out port. Top panel shall be provided with two glass windows for lighting arrangement of 16 watts LED based tube light shall be provided. The glove box structure shall be mounted on a stand and shall be made from M.S. square pipe. Glove box stand shall have wheel with locking arrangement and anchoring bolt.

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f) Gauntlets: (Only for leak testing purpose. Not in the scope of supply) Neoprene black gauntlets to suit the glove port of thickness 0.6mm of length 50mmand cut is finished in the form of O ring uniform thickness0.6mm. It shall be 100% free from pin hole. It shall be seamless construction and have good resistance to acid, alkali and heat up to 70°C.

g) HEPA Filter: A sealed HEPA filter assembly of reputed make shall be incorporated in the roughing line inside glove box in such a location that it shall be easily accessible for removal and replacement from inside the glove box. Capacity- 30CFM and overall dimensions:210±1mm square; depth – 170mm, temperature resistance – upto 120°C, humidity resistance -100%RH, Initial pressure drop-Not more than 25mm of wg at rated capacity of 30CFM, Filter casing material – SS304/304L. h) FABRICATION: Workmanship shall be in accordance with high-grade practice and adequate to achieve the accuracy and finish mentioned in the drawings. All sheet metal and structural work shall be of high quality. All rounded corners and channels in the box frame shall be made of defect-free pressings and shall have radius strictly as per drawings. Gasketting surface area on the glove box frame where panels will seat shall strictly meet the specified and conform to size and shape as indicated in the drawings. In addition, they shall be finished smooth by grinding and shall have absolutely free from steps, pits, dents, scratches and spatters of weld metal. Adequate care shall be taken up to keep the box flat within the range of 0.5mm and free from any waviness. In general, the number of welded joints should be reduced to a minimum utilising the available sheet areas fully. Fabrication of glove box with trough design is acceptable to reduce the welding. The diagonal measurements of the various faces of the box frame shall remain within specified tolerance ASME section VIII shall be applicable unless specified otherwise. i)MACHINING: In general, machining shall be as specified. Care shall be taken to ensure that chattermarks, scratches and burrs are removed from the machined surfaces. All tolerances, sizes and finishes shall be as per the drawings. All the surfaces where “O” ring sits shall have M3 finish and other surface shall have M2 finish. j) INSPECTION AND TESTING: The purchaser shall have access at all reasonable times to all shops and the sub-contractors where material is being fabricated and assembled and all reasonable facilities for such inspection shall be provided. A certificate shall be issued along with each glove box including inspection records and test results. Page 4 of 14

k) Inspection of Raw Materials: All the raw materials to be used in fabrication such as plates, forgings, tubes, bars etc., should be ultrasonically examined for defects. For thin bars and tubes (<25mm) eddy current examination should be carried out. All testing should be performed in accordance with the provisions contained in ASME section 5, article 23, Section IIINB SA 577/578. Welding procedure qualification in accordance with ASME Section IX. If fillet welding is being used, ASME Section IX QW-183( Macro-Micro) should also be met for welding qualification. Besides the tensile test and guided bend test, the results of macro-micro examination should also be indicated in the PQR.( Procedure qualification report). For S.S.304, the fabrication should perform IGCT ( inter granular corrosion test/ sensitization test) on all feed stock and present the results for verification. IGCT as per ASTM,Practice(A) & practice ( E), if required will also be performed at the users end and coupons for the same should be made available to the user from all the feed material stock. The fabricator should submit the chemical and mechanical test reports of the feed material to the user for verification/ acceptance. In case of doubt the purchaser may carry out chemical analysis by taking samples from the plates and other material. The chemical composition thus determined shall confirm to product analysis specified in applicable certificates. For the physical properties testing method for the test shall be in accordance with para 370 ASME Section-II. l)DYE PENETRANT. The procedure for application for Dye Penetrant is as follows: (I) Clean the surfaces with cleaner, (II) apply dye on one side of the weld, and (III) apply developer on the other side of the weld and wait for 15 to 20 minutes. If there is a through and through crack or pinholes, DYE spots will appear on the developer side. Take the corrective action and test the weld again as mentioned above. This procedure shall be strictly followed for all welds. Once welds are checked, the bidder can proceed with other fabrication works. Procedure for Dye-Penetrant examination shall conform to ASTM E-165-T or ASME-Section III ND 5350. All the structure/frames will be checked for dimension, distortions flatness etc. A skew of the glove box frame is not acceptable. All gasketing surfaces of glove box shall be checked for flatness and finish. Finish of the gasketing surface will be checked visually. Placing a full glass-panel against the face will check flatness of the surface and gap will be checked with feeler gauge. Gap shall not exceed 0.5 mm. m)LEAK TESTING

The bidder shall provide the following items: (i) Air blower to create necessary low pressure of 6-8” w.g. (ii) Panels of glass of 914x 914 mm square with 103.5R corner radius (iii) Glass 0-50 range with 0.1 deg.C graduation, (iv) Silicone vacuum grease (v) Diaphragm/ball valve (vi) Other accessories( like tubing, fittings etc) shall be provided by the bidder.

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Procedure for leak testing: The assembly and leak testing of the glove box shall be done in a clean closed room, free from any severe fluctuations of temperature. Special care shall be taken to clean the gasketting surface with alcohol or some other suitable solvent. All gaskets and “O” rings shall be fitted after application of a thin layer of silicone vacuum grease as sealant. All the sides and top shall have glass panels. All panels shall be tightened uniformly, the “O” rings/gaskets not being compressed more than 0.5mm overall. All tubes, pipes and other outlets on the box shall be properly closed using suitable stoppers/rubber corks. The assembled box shall be evacuated by a pump, to negative pressure of not less than 8” w.g. The differential pressure shall be read using the supplied low pressure gauge. Readings shall be taken at one-hour or half an hour interval to record the changing temperature and differential pressure over a period of 24 hours. Leak test records and calculation for the glove box is to be preserved till the assembly is delivered. The leak rate shall be determined from the pressure rise inside the glove box after taking into account the pressure function due to change of temperature of the air in the box. A Centigrade thermometer graduated at 0.1deg.C and with a range of 0-50 deg.C shall be placed inside the glove box to record the temperature change. The average temperature corrected leak rate of the fully assembled box over a period of 24 hours shall be equal to or better than 0.05% of the box volume per hour. The preliminary leak test of the glove box shall be carried out by the bidder. In case leak is found to be high, the bidder shall detect the leaking areas by some approved methods and re-work on the assembly till the tests meet the requirement. 3 ELECTRICAL 3.1 Power Supply 415V±V A.C, 50Hz, Three phases. Power for LANTHANATED MOLYBDENUM heater shall be drawn from two phases. 3.2 Furnace Power Transformer Air cooled transformer having suitable voltage ratio and current ratings and matched to load shall be supplied along with the furnace. The power transformer shall be placed below the furnace inside glove box frame. The bidder should submit all details including dimensional details and layout of the same for purchaser’s approval. The maximum saturation temperature of the transformer on continuous operation of the furnace at highest temperature should not exceed 45ºC. 3.3 Heating Element Heating element shall be in cylindrical shape and made of lanthanated Molybdenum mesh / sheet suitable for continuous operation at 1800 oC.

3.4 Thyristor Control The furnace shall be provided with a thyristorised power supply on primary side of the power transformer. The thyristor control used shall have following essential features: (i) Phase angle firing through 4-20 mA control signal from PID controller

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(ii) Continuously adjustable current limiter (iii) Continuously adjustable over current trip with indication (iv) Soft start (v) Semiconductor fuses for short circuit protection and fuse fail indication (vi) Fan for thyristor cooling (vii) Manual power control facility. The bidder shall furnish detailed technical literature of the thristor for the user’s scrutiny and shall obtain approval from the purchaser.

3.5 Cables The power supply cable will be 1100V grade PVC with FRLS properties insulated copper conductor cable as per current rating is about 15 meters length for interfacing between the control panel and furnace. Control and signal cable will be 1100V grade and 1.5 sq,mm grey multi strand copper FRLS wire.

3.6 Feed through: Suitable feed through glands (leak tight) for high current cable, signal cable, power cable, and control cable shall be provided with the gland size as per fig-3. The water connection and gas connection shall also be routed thro pipe welded on the surface of glove box.

4 INSTRUMENTATION AND CONTROL

4.1 Furnace Temperature Measurement Control Two no’s of thermocouple made of Tungsten-3% Rhenium / Tungsten-25% Rhenium with suitable insulation shall be provided in the furnace to monitor the temperature up to 2000°C and protection for temperature. A PID programmer control unit of shall be provided for temperature control. It shall have features like ramp / soak, programming, auto / manual control, etc. The programmer controller shall have indicators for process temperature, set temperature and other necessary indications the bidder shall furnish detailed technical literature of this PID programmer model for the user’s scrutiny and shall obtain approval from the purchaser.

4.2 Vacuum Measuring Gauges This should consist of digital pirani gauge covering pressure range from 103 mbar to 10-3mbar and with set point controller, automatic range change and auto scanning facility.

4.3 Over Temperature Controller A digital safety controller of reputed make shall be provided for over temperature protection. It shall have set value, actual value and other necessary indications. The controller output shall trip the heating the temperature exceeds the set limit.

4.4 Safety Features: Protection And Interlocks, Alarms And Indications The following safety features shall be incorporated in the design

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 The complete electric circuit shall be designed with necessary protections like MCB’s, MPCB and fuses wherever required.  Heating “ON” shall not be possible with furnace dome / bell open. Visual indication / alarm shall be incorporated for the dome / bell closure.  Heating “ON” shall not be possible without adequate cooling water flow in all cooling channels. Adjustable range flow switches shall be provided in all coolant channels. In case of water failure (or pressure dropping too low) during heating run, and furnace shut down Visual / audio alarm shall be provided through an adjustable delay time.  Excess temperature indication and alarm and it should trip the furnace heating.  Thyristor over current trip indication  Digital True RMS and for indication of heating element current and voltage.  Thermocouple and temperature scanner to monitor the temperature of outgoing cooling water in all channels.  Thermocouple failure protection.  Additional emergency stop switch and additional pairs of switches for bell up & down shall be fitted and to be fixed near the glove box panel.  The furnace should not get restarted automatically once the power is restored after a power failure.  Digital True RMS Ammeter and Voltmeter for supply voltage and currents  Alarm test, reset and acknowledgement shall be provided.  shall not operate unless the vacuum pump exhaust is open.  GB pressure low: Incase, the GB pressure falls below -4” WC, the vacuum pump shall immediately turn off.

4.5 Control Console The control panel shall be as compact as possible with following features:  Digital gauge for vacuum measurement, PID programmer cum controller for temperature control and indication, PLC for implementing various safety interlocks and process control, over temperature ON/OFF controller time display unit, , main ON- OFF contactor and manual push button switches for manual mode of operation etc shall be housed in the control console. All safety interlocks with emergency shut off etc shall be provided in the control console with hooter to indicate the malfunctioning.  Operating push buttons/ switches, indicator lamps, hooter for audio alarm.  A fluorescent light shall be provided inside control panel (for adequate lighting).  An air circulation fan shall be provided inside the control console to cool the critical components and for general air circulation ( one supply air fan and one exhaust fan)  Cable entry shall be made from top.

4.6 Programmable Logic Controller (PLC) All the interlocks, sequential functions as well as control (PID) loops where required of the furnace system shall be affected through PLC. However, it is envisaged to execute the control

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loop function presently using only the single loop controller. The PLC shall be used only to programme the logic control of furnace system. The process of heating shall be controlled by using PID controller. Heating cycle shall be independent and shall be programmed separately. The PLC shall have wide range of flexibility and change of sequence of operation cycle could be programmed in any manner as required by the user. The programmable controller is to be generally designed on the basis of IEC61131 standards. Ladder programming software with PC connecting cable shall be provided. (PC is not in the scope of supply). All the software pertaining to PLC, controller shall also be provided.

5 VACUUM SYSTEMS 5.1 Vacuum Pumps The vacuum system shall include the following vacuum pumps:  Direct driven rotary vane pump of at least 40 m3 / hr capacity (Make: M/s. EDWARDS, U.K.;)  Vacuum valves: Manually operated bellow seal valve to be used for vacuum purposes. For all vacuum pumps, individual thermal overload and short circuit protection shall be provided. 5.2 Safety Features For Vacuum Operation  The pumps shall be interlocked in such a way that roots pump cannot be operated without mechanical pump is in “ON” position  The furnace vacuum should be interlinked with glove box pressure in such a way that the vacuum pump should trip at ( - )3”WG. Number of ports on furnace chamber (i) Port for gas in (ii) Port for gas out (iii) Port for thermocouple (iv) Port for pressure measuring instruments

6 LEAK TIGHTNESS OF THE FURNACE CHAMBER The leak rate of the furnace chamber in vacuum of around 10-2 mbar, shall not exceed 10-3 mbar.litre/sec. The furnace shall be designed to hold slight over pressure (50 to 100 mbar) above atmospheric pressure. Leak rate at 100 mbar over pressure shall not exceed 1 mbar/minute.

7 GAS MODE OPERATION OF THE FURNACE The furnace chamber shall be designed to operate the furnace at slight over pressure (50 to 100 mbar) above atmospheric pressure. The gas inlet system shall contain manually operated A bellow seal needle valve. A Bourdon gauge in addition to digital Pirani Gauge should also be provided to monitor the furnace chamber pressure continuously. A bellow seal needle valve Page 9 of 14

shall also be provided at the outlet side. For measurement of gas flow a rotameter of 10m3/hr range shall be provided. The rotameter shall be made from acrylic.

8 CHARGE CARRIER: One charge carrier stands having four supporting legs of thick Molybdenum rods and with rack arrangement along the length of the stand shall be provided. The tungsten tray of diameter - 120mm, thickness - 2mm and rim of 8.5 mm loaded with charge of fuel material shall be introduced in the rack. The charge carrier should be designed for loading 8 no of trays. A gap of 20 mm between two racks should be maintained.

Note: Dimensions given are indicative. Actual dimensions to be arrived at considering the batch size of 2.5 kg

9 .DRAWINGS SUBMISSIONS BY SUCCESSFUL BIDDER AND ITS APPROVAL  The bidder shall submit following detailed drawings within three (3) weeks from the date of Purchase order for approval of Department:  A General Arrangement drawing (4 copies) indicating overall dimensions of the equipment, orientation of various components, ratings of the motors, make of all major bought out components, clearances, approaches etc.  The following Electrical drawing shall be submitted for approval. Make and rating of the equipment shall be indicated. a. Power wiring and earthing diagram. b. Control wiring diagram. c. Equipment layout, cable routing.  The bidder shall provide any drawing not specified herein, but necessary for a thorough understanding of the construction, operation and maintenance of the equipment.  A complete engineering drawing has to be got approved before starting actual fabrication. Approval by the purchaser of the item design and its control scheme does not conclude that the bidder can escape from the responsibility of the soundness of the design and satisfactory performance of the furnaces. The satisfactory commissioning and demonstration of the furnace as per the purchaser’s specification is the responsibility of the bidder.

10 .QUALITY ASSURANCE PLAN (QAP) The bidder shall submit a Quality Assurance Plan (QAP) to the purchaser for his review and approval before starting actual manufacture and inspection. Based on this QAP, bidder shall carry out manufacture and inspection of the furnaces.

11 .INSPECTION & TESTING a) Stage inspection Stage wise inspection shall be carried out at bidder’s premises during fabrication & assembly of furnace. Page 10 of 14

b) Acceptance at the time of pre dispatch inspection Hot zone temperature, gas atmosphere, interlocks, maximum rated capacity, operating conditions & duration etc., shall be checked and tested for conformation with the specifications and stage operations. Furnace shall be tested by operating the furnace continuously for 8 hours at maximum temperature i.e at 1800 oC Following tools for carrying out inspection shall be arranged by the supplier i. Multi meter ii. Megger iii. Loop calibrator etc. Glove box leak testing , chamber hydro testing, He leak testing of furnace, vacuum testing and hot testing at 1800oC/8 h.

12. PACKING AND TRANSPORTATION  The equipment shall be neatly wrapped with polythene sheets to avoid any ingress of foreign material and shall be suitably packed to avoid damage to the equipment and its surface during handling and transportation. The packing shall be sufficiently reinforced so that it shall withstand repeated handling and prevent damage to equipment.  All the packed equipment shall be transported on a door-to-door delivery basis to the purchaser’s destination without any transshipment in between to avoid any damage to equipment. At the time of receipt of equipment at site, any damage to equipment or contamination observed on the equipment is cause for rejection. The bidderr shall ensure replacement at his own cost for any damage/loss during transit.  Shipment i) All the equipment shall be delivered to RLG Zonal Stores, only after obtaining shipping release from the purchaser or his authorized representative. No equipment shall be dispatched without prior written consent (shipping release) issued by the purchaser or his representative. ii) The bidder shall be fully responsible for protective measures to ensure safe delivery of the equipment.

13. DELIVERY PERIOD Time to deliver the furnace is 06 months from the date of acceptance of purchase order.

14. GUARANTEE The firm shall guarantee the followings for a period of 12 months from the date of commissioning and acceptance.

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Fig.1 Schematic representation of vacuum furnace system installed in Glove box

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Fig.2 Vacuum Furnace

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Fig.3 Electrical Gland

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