Pit Furnace
Pit Furnace
These furnaces are used for a variety of heat treating applications including those requiring inert atmospheres where overhead handling equipment is used. Full opening door exposes entire work space for easy loading. Precision microprocessor based temperature controls and energy-saving insulation maximize the cost efficiency and performance of these rugged units. Ideal for severe service applications – load capacities to 1200 lbs.
Pit Furnace Model Specifications:
Not for use with flammable solvents, vapors, or gases.
| Model | Workspace | Outside Dimensions*(WxDxH) | Max Temp | Heat Input | Insulation Thickness | Operating Characteristics† | Door Type | Height w/ Door Open | Hearth Rating | Approx Shipping Weight | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dimensions(WxDxH) | VolumeCu Ft | ElectricKW | GasBTU/HR | Control Accuracy | Temperature Uniformity | Rise Time (Electric) | Rise Time (Gas) | ||||||||
| PT-181818 | 18" x 18" x 18" | 3.4 | 59" x 54" x 54" | 2,000°F | 15 | 165,000 | 9" | ± 0.3% | ±25°F | 75 | 65 | 69" | 250 | 1,550 lbs | |
| PT-181824 | 18" x 18" x 24" | 4.5 | 59" x 54" x 60" | 2,000°F | 18 | 200,000 | 9" | ± 0.3% | ±25°F | 75 | 55 | 75" | 300 | 1,650 lbs | |
| PT-242424 | 24" x 24" x 24" | 8 | 65" x 60" x 60" | 2,000°F | 26 | 285,000 | 9" | ± 0.3% | ±25°F | 60 | 45 | 81" | 430 | 2,050 lbs | |
| PT-242430 | 24" x 24" x 30" | 10 | 65" x 60" x 66" | 2,000°F | 30 | 330,000 | 9" | ± 0.3% | ±25°F | 60 | 45 | 87" | 500 | 2,200 lbs | |
| PT-303030 | 30" x 30" x 30" | 15.6 | 71" x 66" x 67" | 2,000°F | 36 | 400,000 | 9" | ± 0.3% | ±25°F | 60 | 45 | 93" | 600 | 2,700 lbs | |
| PT-303036 | 30" x 30" x 36" | 18.8 | 71" x 66" x 73" | 2,000°F | 39 | 425,000 | 9" | ± 0.3% | ±25°F | 65 | 45 | 99" | 700 | 2,900 lbs | |
| PT-363636 | 36" x 36" x 36" | 27 | 77" x 72" x 74" | 2,000°F | 52 | 575,000 | 9" | ± 0.3% | ±30°F | 50 | 40 | 106" | 900 | 3,500 lbs | |
| PT-363648 | 36" x 36" x 48" | 36 | 77" x 72" x 86" | 2,000°F | 62 | 675,000 | 9" | ± 0.3% | ±30°F | 50 | 40 | 118" | 1050 | 3,950 lbs | |
| PT-363660 | 36" x 36" x 60" | 45 | 77" x 72" x 98" | 2,000°F | 72 | 800,000 | 9" | ± 0.3% | ±30°F | 50 | 40 | 130" | 1200 | 4,400 lbs | |
* Outside Dimensions
- All Models: Control panel overhang 9″ right side.
- Gas Models:
- Outside depth increases by 10″.
- Combustion blower overhang 36″ rear.
† Operating Characteristics
- 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 oven and minimum exhaust.
- Performance will vary with load and application.
- See Control & Instrumentation Summary for additional details.
Specifications for Pit Furnace
| MODEL | PT-242424 |
|---|---|
| MAXIMUM OPERATING TEMP | 2,000°F |
| AIR FLOW | Radiant |
| CONTROL ACCURACY | ± 0.3% |
| OVEN UNIFORMITY | ±25°F |
| RISE TIME - ELECTRIC | 60 mins |
| RISE TIME - GAS | 45mins |
| WORKS SPACE DIMENSIONS (WxDxH) | 24" x 24" x 24" |
| SHELVES INCLUDED | None |
| NUMBER OF SHELVES MAX | None |
| SHELF CAPACITY | None |
| MAX LOAD CAPACITY | Not Available |
| DOORS | Electric |
| LOADING METHOD | Top |
| APPROXIMATE SHIP WEIGHT | 2050 lbs |
| OUTSIDE DIMENSIONS (WxDxH) | 65" x 60" x 60" |
Standard Features for Pit Furnace
Certifications
- UL Listed Control Panel
- Meets the Requirements of the Following Standards:
- NFPA 86 (Standard for Ovens and Furnaces)
- NFPA 70 (National Electric Code)
- FM (Factory Mutual)
- OSHA
- Caution:
- When processing combustible material fire protection should be considered
- Not for use with flammable solvents or vapors. Other models available for these applications. For more information see Class A Solvent Processing page at this website
Safety Equipment
- Adjustable manual reset excess temperature interlock to turn off heat on malfunction of main temperature controller
- Electric Heat Includes
- Separate heating element control contactors to turn off heat on malfunction of main control contactors
- Door interlock turns off power to heating elements when door is opened to protect operator from line voltage at heating elements
- Gas Heat Includes
- Multiple modulating burners fired under hearth from opposing sides to circulate heated air
- Automatic pre-ignition purge period to clear accumulated gas or fumes from furnace
- Push button electric ignition
- Microprocessor based electronic flame safeguard protection for each burner to continuously monitor flame and close gas valves if flame is not present
- Combustion air blower
- Combustion Blower air flow safety switch to close gas valves on loss of combustion air flow
- High and Low gas pressure switches to confirm safe operating pressure range
- Two pilot valves for each pilot to guarantee gas flow to pilot can be stopped
- Two main safety shut off valves for each burner with valve seat position indicator to assure gas flow to each main burner can be stopped
- Proof of closure switch on one main valve at each burner to prevent igniting pilot unless main valve is closed
- Leak test station at each pilot and main burner valve to allow testing for leakage through valve
- Door interlock drives main burners to low fire as door is opened to protect operator from flames
Controls
- Digital temperature controller
- LED pilot lights
- On-off heat switch
- 5 kA short circuit current rating (SCCR)
Construction
- Choice of
- Air or Inert Atmosphere construction
- Electric or Gas heat (Air construction only)
- 208 volt, 230 volt or 460 volt, 3-phase, 60 HZ – other input power available
- All welded construction
- High temperature Kanthal A-1 coiled wire heating elements supported in vacuum cast refractory ceramic fiber located on all side walls
- 1000 BTU per cubic foot natural gas at 2 psig pressure – propane available. Inlet 1” NPT up to 800,000 BTU/hr, 1-¼ “ NPT to 1,000,000 BTU/hr, 1-½” NPT above 1,000,000 BTU/hr
- Insulated with 9”of light weight, energy saving refractory ceramic fiber
- Load supporting floor insulated with 2” of 18-½ lbs per cubic foot density 1900⁰F block and 4” of insulating refractory
- 3/16” steel plate reinforced furnace shell with Trilite Green enamel finish
- ½” thick steel top plate
- Fire brick throat to protect furnace during loading
- Brushed stainless steel control panel face
- Powered door supported by structural steel arms, hinged at rear with heavy duty shaft and pillow block bearings
- Electric door: Electromechanical operator and lever arm rotate door shaft
- Air door: Air cylinder connected to heavy duty sprockets and roller chain rotate door shaft
- Soft insulation on door hot face seals against throat brick and steel front plate
- Fully assembled and factory tested
- 1 year limited warranty
Modifications & Accessories for Pit Furnace
-
Programmable Temperature Controller
Oven modification adding a programmable Temperature Controller. Microprocessor based, digital indicating, thermocouple actuated, in lieu of standard controller.
-Program Parameters: 40 profiles of up to 50 steps each, a real-time clock with battery backup to allow starting profile at any time of day
-Digital Display, 4.3” color touch screen
-Accuracy, ±0.1% of span plus 1 degree display error
-Connectivity, Relay output for alarm or other notification, two (2) USB ports, Ethernet compatible
Also Available:
-Up to four (4) control channels of temperature, relative humidity or vacuum
-Monitor up to16 sensors
-Math and logic functions
-Digital inputs and outputs
-Data logging
-Graphic Trending
-
Recording Thermometer
Accessory adding a Recording Thermometer. Thermocouple actuated.
- Record: 10″ diameter circular chart 24 hour chart rotation
- Digital Display: 0.56″ high, LED, alphanumeric, 4 digit display; LED status display
- Accuracy: ±0.25%of span plus 1 degree display error
-
SCR Power Controller
Electrical modification adding an SCR Power Controller. Features:
•Silicon controlled rectifier power controllers are completely solid state industrial controllers that ensure precise proportioning of electric power to the heating elements.
•Oven temperature is maintained smoothly and evenly over the entire temperature range of the unit.
•SCR power controllers minimize maintenance, as there are no moving parts or electrical contacts to wear out.
•Heating element fatigue is reduced since the elements do not cool between releases of electric power.
•Zero voltage firing, including the first one half cycle of voltage, minimizes radio frequency and electromagnetic interference.
•Transient voltage suppressor networks are included, and the units are provided with protective fusing.
-
Digital Shut Down Timer
Accessory adding a Digital Shut Down Timer. Shuts down oven, selectable range, continuous “hold” feature.
-
Install Customer Supplied Temperature Controller
Modification installing a customer supplied temperature controller in lieu of standard controller.
-
Digital Batch Timer
Oven modification adding a Digital Batch Timer. Uniformly timing batch operations, continuous alarm with door interlock, alarm sounds at end of preset time until door is opened or timer reset.
-
Supply Oven Without Controller
Supply without temperature controller. Supply cutout, thermocouple, and wires only. Customer to supply and install temperature controller.
-
Program Timer
Oven modification adding a programmable 24 hour, 7 day timer.
-
Equipment Shut Down Via Event Output
Modification adding a Equipment Shut Down Via Event Output. Shuts down oven via event output on programmable controller.
Custom Furnaces
-
Model PT363648-HT-ATM Inert Atmosphere High Temperature Pit Furnace
Serial #: 115058A0615Used for heat treating automotive parts in baskets. Brick interior with rod overbend heating elements.
- MAX TEMP: 2200ºF
- WORKSPACE DIMS (WxDxH): 36" x 36" x 48"
