Long Service Life & Ease of Maintenance
Accurate Temperature Control Our tabletop furnaces are equipped with state of the art ramp to set point digital microprocessor temperature controller.
The specially designed grooved bricks optimize heat transfer and fully support the FeCrAl heating elements for maximum life expectancy. The “open coil heating elements” are easily accessible for maintenance.
The highest quality low-density refractory bricks used in the construction of its chamber assure maximum insulation while minimizing heating or cooling cycles.
Superior Heat Distribution
A special attention is given to the distribution of the heating elements to assure optimal temperature uniformity throughout the furnace.
A wide choice of options gives our units the flexibility to suit a variety of commercial, industrial and laboratory heat treating applications.
Muffle Furnace Characteristics
- Cabinet design & construction choice of Enamel coated 16 gauge steel or (304) stainless steel
- Horizontal opening door heavily hinged door With a 180° opening
- Insulation 4½”/11cm pre-grooved refractory bricks (With the exception of the f50, which is 2 ½”)
- Temperature controller microprocessor temperature controller, with auto tuning pid parameter offering ramp/soak program capability
- Heating elements low watt density fecral heating elements
- Furnace chamber hearth plate the furnace comes standard with a cordiorite hearth plate.
- Vertical opening door Counterbalanced guillotine lifting door with “Zero weight positioning”
- Furnace floor stand Heavy-duty furnace stand
- Ni-cr heating elements Special heating elements used in corrosive environment
- Programmable controller 2 programs with 8 segments ramp/soak
- Solid state relay (ssr) For increase temperature accuracy and silent operation
- Adjustable exhaust vent Slide gate located on top of furnace to vent corrosive vapors, also comes with a peephole in door
- High limit controller Automatically shutdown heating elements when maximum temperature is exceeded
- Door safety switch Automatic Shut off heating elements when door is opened
- 3 phase 208-240v Available for the F300/F400
- Heating elements in door Offers greater heat distribution
The temperature curve presented in these graphs is based on testing performed on furnaces without chimneys, for furnaces coming with chimney option, temperature ramp-up time will increase by 15%.
Standard Laboratory Muffle Furnace Model
- PRODUCT FEATURES: all models are made of 14 ga steel (green enamel finish).
- QUALITY INSULATION: low-density refractory bricks, 4½” thick 2,300°F rated.
- LONG SERVICE LIFE & EASE OF MAINTENANCE grooved bricks optimize heat transfer and make maintenance much easier. FeCrAl heating elements are located into the groove of the bricks (but not moulded into the brick) and can be replaced without taking any bricks out. By being in the brick groove, radiant heat from the element is lowered, which offers a better temperature uniformity. The elements are protected from any contact that can occur during the furnace loading. This kind of design also allows the operator to replace just a few bricks when required.
- ACCURATE TEMPERATURE CONTROL: standard controller used is Watlow model PM6 (1/16 DIN) (Single set point controller). Base unit for simple applications. Just input you’re work temperature and let the Watlow EZ-Zone PM6 do its job with its precise PID control feedback loop. This unit also includes built in high limit (HL) overheat protection. HL is easy to program and reset.
- HORIZONTAL OPENING DOOR: heavily hinged door with a 180° opening. We offer a rugged industrial door design.
- FURNACE CHAMBER HEARTH PLATE: all furnaces come with a Cordierite hearth plate.
Model Power Output
- “HP” MODELS: ramp up time is faster than standard models (see brochure for time Vs. Temperature curves). The “HP” version is especially appropriate when ordering the slide gate chimney option described below.
Controls & Instruments
- PROGRAMMABLE TEMPERATURE CONTROLLER (4P/10S): Basically the same unit as the single set point unit but with programmable Capabilities. You have four (4) programs with 10 segments per program for a total of 40 segments. You can program your ramp-ups, soak and ramp down time temperature. This system permits you to have defined programs linked to your processes and treatment necessities. This unit also includes built in high limit (HL) overheat protection. HL is easy to program and reset.
- USB COMMUNICATION: This add-on USB port links up to your programmable temperature controller. By using you’re the freeware provided by Watlow and a laptop permits you to quickly modify or set recipes and change desired parameters.
- PROCESS TIMER: This unit paired with standard single set point temperature controller makes the easiest way to use our furnace when dealing with simple process requirements. Just set quantity and desired units, countdown will start when set temperature is obtained giving you consistent soak times. After soak time is finished unit shuts down and awaits next command from operator.
- 7-DAY TIMER: This option permits you to have the furnaces start automatically at defined time. Perfect to pre-heat furnace.
- SSR: This electronic part increases control accuracy in soaking and is much quieter than the mechanical contactors. Makes for a more sturdy electrical system because you don’t cycle contactor.
- TEMPERATURE CONTROLER/RECORDER: Info to come
- PAPER CHART RECORDER: Info to come
- VERTICAL OPENING DOOR: counter weighted vertical opening door offered on all models. Makes loading parts in furnace easier and safer. Both hands can be used to handle parts.
- HEATING ELEMENTS IN DOOR: Elements in the door are available for F300 and F400 models only. Customers will need this option usually for burn-off applications or to prevent condensation on the door. Can also help in lower temperature uniformity (around 1100°F).
- DOOR SAFETY SWITCH: automatically shuts off the power to the elements as door is opened and restores it as door is closed. Prevent accidental electrical socks if operator touches live element with metal tongs. This option is also provided with horizontal hinged door with elements in door to prevent accidental scorching.
- ADJUSTABLE EXHAUST VENT: it’s a slide gate on top of the furnace in case corrosive vapours have to be vented. When this option is selected, a peephole is included.
- NiCr HEATING ELEMENTS: at no extra charge. These elements are usually used for corrosive applications, in Nitrogen atmospheres and for Dental Lab applications.
- CORRUGATED HEARTH PLATE: This hearth plate is corrugated permitting you to complete lost wax process thus letting melted wax to be funnelled in the bottom of the furnace.
- SS 304 CASING: This option especially suited for dental laboratories and corrosive applications.
- FURNACE FLOOR STAND: we offer a heavy-duty floor stand. Can be ordered at specific high.
- INERT ATMOSPHERE (OPTION): This option allows you to generate a protective atmosphere in your oven at high temperature. Such type of atmosphere minimizes oxidation of the steel pieces. This option includes the following items:
• N2 gas panel
• Pressure regulator – 30ZAA201595680100000
º flow meter calibrated for nitrogen (N2) with integrated flow control – MAX 9.5 scfm (N2)
Laboratory Muffle Furnaces Specifications
- Valves & Piping necessary; mounting oven
- Ports: Input / Output
Benchtop Muffle Furnace Maintenance
Lets take a minute to talk about some of the parts which need to be maintained in your furnace. First, it’s the heating elements. We use a heavy-gauge wire with a low lob loading for a longer life. The wires are supported in removable plates. When a wire does burn out, the entire assembly with the wire slides out, a new plate with the wire slides back in. You do not have to touch or remove the insulation when replacing one of our heating elements.
Next, is the hard plate. The floors in our chambers are aligned with a dense plate which we call the hard plate. It protects the softer insulating fire brick underneath and supports the workloading. If the plate cracks, it can be removed, slides out through the front, the new plates slides right back in. Next, is the insulation. The insulation in our furnaces has always consisted of insulating firebrick. Our models is dry fit; it’s wedged in place which is better for thermal contraction and expansion as the furnace heats and cools. The bricks can be replaced individually. Mortaring is neither necessary or recommended.
Also, just to dispel concerns about the white insulating material, please note that insulating fire brick does not and has never contained asbestos. Finally and perhaps most important is your thermal couple. The thermal couple is the probe which senses the chamber heat, sends a signal to the temperature controller telling the furnace to cycle on and off. We recommend replacing the thermal couple every 6 months to a year to maintain accurate control and help your heating elements operate more efficiently and last longer.
We stocks all of these parts I talked about and can be generally shipped in one to two days. Installation is easy with minimum downtime and will help keep your furnace in operation for many years.