1、 Manufacturing StandardsFord Motor Company197708 HEAT TREAT FURNACES BHXEngineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 1 of 71. TYPES OF FURNACES:1.1 THESE STANDARDS SHALL APPLY TO THE FOLLOWING TYPES OF FURNACES:(A) Hardening furnaces.(B) Carburizing furnace
2、s.(C) Draw and annealing furnaces.(D) Normalizing furnaces.2. GENERAL:2.1 When applicable, the following information shall be furnished tothe issuing division by the bidder of heating equipment.(A) Type of furnace or oven.(B) Maximum operating temperature.(C) Time cycle for mean speed variable.(D) C
3、apacity in net pounds per hour.(E) Size of tray and estimated weight of tray.(F) Number of control zones.(G) Connected load.1. Specify kind of gas and estimated gas consumption.2. Specify voltage and estimated kilowatt hours per hour.3. Specify horsepower and R. P. M. of connected motor load.(H) Gas
4、 pressure required at burners.(I) Overall dimension.(J) Heating chamber dimensions.(K) Specify material thickness of shell, walls, roof and hearth.(L) Composition of metals subjected to furnace heat.(M) Specify type of gas purifier provided.(N) Furnace atmosphere.1. Type of atmosphere gas.2. Capacit
5、y of gas generator.3. Number of retorts in generator.4. Material of retort.(O) Quenching.1. Capacity of quench tank in gallons.2. Specify type of quench oil cooling provided.3. Specify type of quench oil agitation.(P) All controls shall conform to Ford safety regulations.(Q) Specify cooling medium p
6、rovided for door sills.(R) Specify where water cooling of any furnace parts is required.(S) If cooling is required, how many G.P.M.?(T) State type of drive on continuous furnaces.(U) Unless otherwise specified, contractor shall perform installa-tion, furnish temperature controls, ventilating hoods a
7、nd safetyguards.Manufacturing StandardsFord Motor Company197708 HEAT TREAT FURNACES BHXEngineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 2 of 72.2 Provisions of BXI shall apply unless otherwise specified herein.2.3 (A) The method of conveying stock, such as push
8、ers, walking beams,skid rails, roller rails, roller hearths and conveyors, shall begoverned by the type of stock being processed.(B) All pushers should be operated by hydraulically actuatedcylinders.2.4 (A) Gas fired furnaces shall be used, wherever possible.(B) All gas furnaces using coke oven gas,
9、 shall be equipped withgas purifiers.(C) Heavy duty centrifugal type blowers shall be used to supplycombustion air. Combustion air blowers shall be equipped with anintake filter capable of retaining air-borne solids thatwould adversely affect the normal performance of the combustionsystem. Filter sh
10、all be easily removed for cleaning and shall belisted by Underwriters Laboratories, Incorporated as either Class 1or Class 2.2.5 (A) Furnaces operating at temperatures below 1300 F shall use opentype burners.(B) Furnaces operating at temperatures above 1300 F may use closedtype burners.2.6 All alloy
11、 parts both stationary and moving shall conform to FordMetallurgical and Chemical Process Standards, where applicable.3. ELECTRICAL AND SAFETY SPECIFICATIONS:3.1 Provisions of Ford Manufacturing Standard Section E shallapply where appropriated.3.2 Formation of hazardous compounds such as cuprous ace
12、tylide(Cu2C2) in furnaces and related equipment shall be precludedby equipment design.Furnaces and gas atmosphere generators shall not use coppercomponents in the presence of rich exothermic gases (Class AGA102) that may contain acetylene gas.Manufacturing StandardsFord Motor Company197708 HEAT TREA
13、T FURNACES BHXEngineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 3 of 74. EXPLOSION VENTS:4.1 All furnaces and ovens containing flammable air-gas mixtures shallbe provided with unobstructed relief vents for relieving internalexplosion pressures. A minimum ratio o
14、f explosion relief area insquare feet to the explosion containing volume in cubic feet is1:14. The areas of permanent openings and access openings providedwith doors having approved explosion access openings provided withdoors having approved explosion venting latches can be consideredas relief vent
15、ing areas.4.2 Guards shall be installed in front of doors where necessary toprevent obstruction by stock or other equipment.4.3 Roof panels held in place by gravity only are preferred asexplosion relief vents.These panels shall have strength, rigidity and insulating valuecomparable to that of the ge
16、neral oven construction.5. DOORS AND VESTIBULES:5.1 Doors should be oil cooled, wherever practicable.5.2 Doors shall contain a minimum of 5“ of best quality refractorybrick.5.3 Chrome ore should be used for all muffle seals.5.4 Vestibules should be constructed with only the volume andclearances nece
17、ssary to permit the easy passage of stock and trays.6. QUENCHING OILS AND SOLUTIONS:6.1 Circulation shall be adequate to quench parts to full hardness.6.2 Quench tanks should be equipped with a conveyor for the continuousremoval of scale on installations where an excessive accumulation ofscale is ex
18、pected.6.3 Quenching oil shall conform to process specification No. M-508-B.6.4 The operating temperature of quenching oil shall be 125 F minimum.6.5 Quenching oil should be maintained at the proper operatingtemperature by installing adequate thermostatically controlledheating or cooling equipment,
19、as required.Manufacturing StandardsFord Motor Company197708 HEAT TREAT FURNACES BHXEngineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 4 of 76.6 Suitable filters shall be installed either at a central system orat each individual quench tank to filter and purify th
20、e oil.6.7 (A) The operating temperature of caustic soda solutions should bebetween 90 F and 110 F.(B) Caustic soda solutions should indicate a specific gravity of 7to 10 when checked with a beaume hydrometer.7. NORMALIZING FURNACES:7.1 This specification shall apply only to high temperature zonesope
21、rating at 1700 F to 1800 F.7.2 (A) Thickness of furnace shell, shall be 1/4“ minimum steel plate.(B) The minimum wall and roof thickness shall be 13“ of firebrickand insulation.(C) Insulation shall be in the form of bricks or blocks. Powderedinsulation must not be used.(D) Doors shall be constructed
22、 in accordance with paragraph 5.7.3 Heat loss shall not exceed 600 BTU per sq ft of wall area per hour.7.4 The following methods are acceptable for use in cooling zones.1. Air cooling2. Water cooling3. Air circulation8. HARDENING FURNACES:8.1 Hardening furnaces shall operate at temperatures between
23、1400 F and1650 F.8.2 (A) Thickness of furnace shell, shall be 1/4“ minimum steel plate.(B) The minimum wall and roof thickness shall be 13“ of bestquality firebrick and insulation.(C) Insulation shall be in the form of bricks or blocks. Powderedinsulation must not be used.(D) Doors shall be construc
24、ted in accordance with paragraph 5.8.3 Heat loss shall not exceed 600 BTU per sq ft of wall area per hour.Manufacturing StandardsFord Motor Company197708 HEAT TREAT FURNACES BHXEngineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 5 of 79. GAS CARBURIZING, CLEAN HAR
25、DENING AND CARBONITRIDING FURNACES:9.1 (A) All gas carburizing, clean hardening and carbonitridingfurnaces shall be radiant tube fired, unless otherwise specified.(B) Radiant tubes must operate at a negative pressure in relationto muffle and chamber pressures to prevent unbalancing andcontamination
26、of the furnace atmosphere. This arrangement also aidsin the detection of leaking tubes.9.2 The maximum operating temperature of furnace shall be 1700 F.9.3 (A) Thickness of furnace shell, shall be 1/4 “ minimum steel plate.(B) The minimum wall and roof thickness shall be 13“ of bestquality firebrick
27、 and insulation.(C) Insulation shall be in the form of bricks or blocks. Powderedinsulation must not be used.(D) Doors and vestibules shall be constructed in accordance withparagraph 5.9.4 Heat loss shall not exceed 600 BTU per sq ft of wall area per hour.9.5 Units for the preparation of gas atmosph
28、ere shall conform with 15.10. DRAW FURNACES:10.1 (A) All batch type draw furnaces operating at temperatures below600 F shall be heated electrically and be of a circulating type.(B) Furnaces operating at temperatures above 600 F may be gas fired.(C) Where sulphur is present in the gas (10 grains per
29、100 cu. ft.or more) the heater shall be indirect fired. Where no sulphur ispresent the heater may be direct fired.(D) Unless otherwise specified, open type heaters shall be used.(E) All continuous draw furnaces shall be the re-circulating type.10.2 (A) All draw furnaces shall have a 4“ minimum of gl
30、ass woolinsulation, or approved equal.Manufacturing StandardsFord Motor Company197708 HEAT TREAT FURNACES BHXEngineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 6 of 711. LIQUID CYANIDE FURNACES:11.1 (A) Liquid cyanide furnaces shall be gas fired and shall not exc
31、eed1650 F operating temperature.(B) Burners shall be designed and arranged to prevent flameimpingement of the pot.(C) Burner blocks should be made of alundum or aluminum silicate.11.2 (A) The shape of salt bath furnaces may be either round orrectangular.(B) The thickness of the furnace shell, shall
32、be 3/8“ steel plateminimum for top and bottom and sides of furnace.(C) A minimum of 9“ of insulation and or insulating firebrick shallbe used on top and bottom and sides of furnace.12. LEAD POT FURNACES:12.1 Lead pot furnaces shall be electrically heated.12.2 The operating temperature must not excee
33、d 1600 F.12.3 (A) The pot shall be made of 35 Ni - 15 Cr alloy or equal.(B) Thickness of furnace top and bottom shell, shall be 3/8“ minsteel plate.(C) Thickness of furnace side shell, shall be 1/4“ min steel plate.13. NITRATE FURNACES:13.1 Nitrate furnaces may be gas or electrically heated.13.2 The
34、 operating temperature must not exceed 1050 F.13.3 (A) Thickness of furnace shell, shall be 3/16“ min steel plate.(B) The minimum side and bottom thickness shall be 4 - 1/2“ ofinsulation.(C) Nitrate pot should be made of cast or fabricated steel andsprayed with a minimum of .015“ 35 Ni - 15 Cr alloy
35、 on the O.D.Manufacturing StandardsFord Motor Company197708 HEAT TREAT FURNACES BHXEngineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 7 of 714. OIL BATH FURNACES:Oil bath furnaces must be electrically heated.14.2 The operating temperature must not exceed 400 F.14
36、.3 (A) Thickness of furnace shell, shall be 3/16“ min steel platewelded construction.(B) The minimum wall and bottom thickness shall be 4-1/2“ ofinsulation.(C) Oil bath pot shall be made of cast or fabricated steel.15. UNITS FOR PREPARATION OF GAS ATMOSPHERES:15.1 Manifolded generators shall be equi
37、pped with three (3) circulartype centrifugally cast gas bottles with a minimum capacity of 1000cu. ft. per bottle.15.2 Isolated generators, for special work, should provide the capacityrequired by the specific furnace.15.3 Gas pumps shall be rotary positive displacement type.15.4 (A) Gas generator burners shall be designed to provide uniformheat. Closed type burners must be used. The number and location ofburners shall be determined by the builder.(B) All generators must be equipped with adjustable and indicatingair and gas mixing devices.
