1400°F FORCED CONVECTION HEAVY DUTY ELECTRIC AND GAS TEMPERING FURNACES
Grieve standard 1400°F Tempering
Furnaces are used for a variety of heat treating applications including those
requiring inert atmospheres. Recirculating blower provides high velocity vertical
down air flow for excellent heat transfer from 800°F to 1400°F. Precision
microprocessor based temperature controls and energy-saving insulation maximize
the performance of these rugged units.
Standard Tempering furnace ovens from Grieve meet the requirements of
National Fire Protection Association Standard 86, Industrial Risk Insurers,
Factory Mutual and OSHA standards. For some applications, such as those involving
special atmospheres or hazardous locations, the above organizations require
additional safety devices.
Controls
—Digital, microprocessor based, thermocouple actuated, indicating temperature
controller
—Modulating burner on gas furnaces
—Motor control push buttons and on-off heat switch
—Easy-to-see pilot lights
Safety Equipment — Electric Furnace
—Adjustable, thermocouple actuated, manual reset excess temperature controller
—Separate heating element control contactors
—Recirculating blower air flow safety switch
Safety Equipment — Gas Furnace
—Adjustable, thermocouple actuated, manual reset excess temperature controller
—Electronic flame safeguard protection
—Stainless steel powered forced exhauster
—Exhauster air flow safety switch
—Recirculating blower air flow safety switch
—Purge timer
—High and low gas pressure switches
—Two pilot safety shutoff valves with leak test stations
—Two main safety shutoff valves with leak test stations (Industrial Risks
Insurers vent valve only provided on specific request)
—Valve position indicator on main safety shutoff valves
—Over 400,000 BTU/HR safety shutoff valve interlocked with purge timer
Construction
—Vertical down air flow specifically designed for tempering
—High pressure, air cooled, stainless steel recirculating blower
—Adjustable patented opposed louvers on full coverage supply and return
ductwork
—3/16" steel plate reinforced furnace shell
—1/2" thick steel front plate
—16 gauge stainless steel interior
—Work space bottom reinforced with stainless steel grid
—Brushed stainless steel control panel face
—Powered vertical lift door; hot side faces away from operator
—Energy-saving lightweight ceramic fiber insulation
—Fast heat-up and cool-down
—Built-in baffles prevent radiant heat
—Adjustable fresh air intake and exhaust dampers
—1 year limited warranty
All equipment fully assembled and individually factory tested
SPECIFICATIONS Back
to Top NOT FOR USE WITH FLAMMABLE SOLVENTS,
VAPORS OR GASES.
Model
Work Space
Outside Dimensions* (WxDxH)
Height Door Open
Blower
Door Type
Hearth Rating Lbs‡
Heat Input
Operating Characteristics†
Approx Shipping Weight
Model
Dimensions (WxDxH)
Volume Cu Ft
CFM
HP
KW
BTU/HR
Control Accuracy
Furnace
Uniformity
Rise Time
230V
460V
TF-183618
18" x
36" x 18"
6.7
35" x 87" x 74"
78"
2400
3
Electric
400
30
190,000
± 0.3%
±12°F
95 min
85 min
3100 lbs
TF-183618
TF-243624
24" x
36" x 24"
12
47" x 92" x 80"
90"
3500
5
Electric
600
42
285,000
± 0.3%
±14°F
95 min
85 min
4000 lbs
TF-243624
TF-304830
30" x 48" x 30"
25
53" x 106" x 86"
102"
4250
5
Electric
900
52
355,000
± 0.3%
±14°F
90 min
80 min
5200 lbs
TF-304830
TF-364836
36" x 48" x 36"
36
59" x 111" x 126"
126"
5300
5
Air
1100
65
450,000
± 0.3%
±20°F
90 min
80 min
6400 lbs
TF-364836
TF-366036
36" x 60" x 36"
45
59" x 121" x 126"
126"
6000
7-1/2
Air
1300
74
510,000
± 0.3%
±20°F
90 min
80 min
6800 lbs
TF-366036
TF-484848
48" x 48" x 48"
64
71" x 114" x 150"
150"
8000
10
Air
1500
100
660,000
± 0.3%
±22°F
80 min
70 min
8700 lbs
TF-484848
TF-487248
48" x 72" x 48"
96
71" x 152" x 150"
150"
9600
15
Air
2200
120
800,000
± 0.3%
±22°F
80 min
70 min
9950 lbs
TF-487248
*All Models
—Control panel overhang 9" right side.
Blower motor overhang 18" rear except 20" on 15
HP.
Gas Models
—Burner overhang 18" right side.
325 CFM exhauster to 510,000 BTU/HR, 650 CFM above.
†Accuracy
as percent of controller span. Uniformity at 100°F below maximum
temperature. Rise Time in minutes to 100°F below maximum temperature.
Tests run with empty furnace. Performance will vary with load and
application. See Bulletin TC-920 for
additional details.
‡Uniformly distributed.
All Models
— 208 volts, 3-phase, 60 Hz
— 230 volts, 3-phase, 60 Hz
— 460 volts, 3-phase, 60 Hz
— Other electrical characteristics available
Wall insulation, 7" thick, consisting of:
— 1" of 2300°F, 8 lbs/cf ceramic fiber blanket
— 2" of 1700°F, 4 lbs/cf ceramic fiber blanket
— 2" of 1900°F, 15 lbs/cf block insulation
— 2" of 1200°F rockwool insulation
Floor insulation, 6-1/2" thick, consisting of:
— 4-1/2" of 2300°F insulating firebrick
— 2" of 1900°'F, 18-1/2 lbs/cf block insulation
Electric Models
Safety devices as listed at the top of this bulletin. Heating element contactors
electrically interlocked with door to shut off power to heaters as door opens
and restore power when closed. High temperatures alloy coiled wire heating elements
supported in alloy rack. Heating elements located in heat chamber upstream of
the recirculating blower. Exhaust outlet 4" diameter.
Gas Models
— 1,000 BTU natural gas at 2 psig pressure; 1" NPT inlet up to 800,000
BTU/HR
— Other gas characteristics available
Safety devices as listed at the top of this bulletin. Automatic pre-ignition
purge period and push button electric ignition contributes to ease of operation.
Modulating gas burner fires into chamber upstream of the recirculating blower.
Gas burner protected with electronic flame safety relay. Door interlock switch
drives main burner to low fire when door is opened and restores control when
door is closed. Exhaust outlet 6" diameter.
Furnace shell is made of 3/16" thick steel plate reinforced with structural
steel. Doorsill constructed from firebrick to protect furnace during loading.
Stainless steel grid at bottom of work space to distribute loading. Soft insulation
on door provides an excellent heat seal by pressing against the vestibule refractory
and the 1/2" thick steel front plate. Exterior painted with Trilite Green enamel.
Each features completely wired, side access
UL listed control panel assembled on the furnace enclosing terminals for incoming
power, temperature controllers, push buttons and pilot lights.
ELECTRIC DOOR
Door pivots upward above furnace, clearing front for easy loading. In the closed
position, full door weight seats door firmly against furnace face. Structural
steel pivot arms are supported at furnace sidewalls by bearings and connected
to a heavy duty electromechanical actuator. The door is controlled by a switch
at the furnace control panel.
AIR DOOR
Door rises vertically in front of the furnace hanging from heavy duty roller chain,
sprockets, shaft and pillow block bearings. In the closed position, rollers at
the sides of the door engage support brackets to force the full door weight against
the furnace face. Large diameter air cylinder rotates support shaft to lift the
door. The door is controlled by a manual air valve with supply filter, lubricator
and regulator.
Circulation Diagram
(Side View)
Full vertical downward air flow provides
excellent heat transfer and uniform
temperature distribution.
ADDITIONAL
EQUIPMENT AVAILABLE Back to Top
See Bulletin TC-960 for modifications and other
optional equipment.
Programmable Temperature Controller,
microprocessor based, digital indicating, thermocouple actuated, in lieu of
standard controller Option PTC3
Recording Thermometer,
thermocouple actuated, 24-hour, 10" diameter circular chart used in conjunction
with standard controller Option RT
Programmable Recording Temperature
Controller, microprocessor based, thermocouple actuated, digital display,
24-hour, 10" diameter circular chart, in lieu of standard controller Option PRTC3
Digital Timing System,
incorporated into standard temperature controller, 99 hour 59 minute range,
starts timing at temperature set point and shuts down furnace at end of set
time Option DTS3
Shut Down Timer, with continuous
"hold" feature; 1, 5, 10 or 30 hour range Option SDT
Batch Timer, for uniformly
timing batch operations. Continuous alarm with door interlock; alarms at end
of preset time period until door is opened or timer reset; 1, 5, 10 or 30
hour range Option BT
Automatic Door Switch,
turns off blower and heat when door is opened. Restores blower and heat on
electric models, blower only on gas models, when door is closed Option ADS
Inert Atmosphere Construction,
electric only, includes continuously welded shell, inert atmosphere gas inlet
and outlet, sealed terminal boxes, recirculating blower shaft seal, high temperature
door gasket, optional forced cooling systems are available at additional cost Option IAC
Inert Atmosphere Inlet Piping,
with indicating flow control and manual gas valve. Specify atmosphere Option IAIP
UL LISTED CONTROL
PANEL
