Gemlab Furnace Model V1200-80

Gemlab's model V1200-80 is a desktop, top-loaded, vertical muffle furnace, occupying minimum work space designed by Ted Themelis of unparallel versatility and impeccable design of its class not found anywhere in the industry. Any gemstone may be loaded and heat-treated for 1-2 hours (to 1200oC), days (to 1150oC), weeks/months (at 1100oC) in air, oxidizing or nitrogen controllable atmosphere with or without chemicals additive. Also any gemstone can be heated in vacuum to 1200oC.

Model V1200-80 \

Very economical with low electric power consumption
Safe and easy operation
Long-lasting performance
Features & specifications of standard equipment
Desk-top, only 360 (D) x350 (W) x 560 (H) mm
Feather-weight, only 50 kgs
Oper. temp. 1100oC (continuous); 1150oC (short time); 1200oC
Double steel shell design ensures outside furnace skin temperature below 60oC (EN661010 safety standard)
Cooling fans ensuring continuous ventilation
Single gas inlet port allows single gas purge assembly including a flowmeter, pressure gauge, on-off valve..
Vertical tube, top loading/unloading muffle attachment provides direct gas purging of gas using single-flow meter air, oxygen, oxygen-nitrogen, or vacuum operation to maximum 1200oC..
Aluminum 3-pc set flange assembly for sealing hermetically one end of the alumina muffle
All alumina ceramics (99.5% pure): 1 pc. Close One End muffle tube, 1 pc. straight crucible, 6 pcs dishes, 1 pc disk; spacer
Exhaust assembly: bubbler, backpressure gauge, fittings, hoses
Vacuum system: 2-stage pump, gauge, fittings, hose
Thermocouple "K-type" assembly with t/c extension wire
Artificial Intelligent auto temperature programmer controller
SCR (Silicon Control Rectifier) Controller & Trigger)
High quality Kanthal wire A1 heater.
1500-grade hot face with excellent temperature uniformity
Controls: Lighted ON-OFF switch, heater ON-OFF switch, heater indicator, buzzer-alarm, ammeter, voltmeter
Plugs to any 220Vac-10A single-phase electric outlet
Features of Model V1200-80

Direct gas purge mode or Vacuum mode
In this mode the gemstones are loaded from the top opening of an alumina Close One End tube and hermetically sealed with the 3-pc set flange. Under this configuration, oxygen or nitrogen can be directly purged into the muffle via the gas purge assembly at any temperature to 1200oC and directed out of the heat treating room via an exhaust assembly (open-loop system). Chemical additives may or may not be used. Vacuum can be applied instead of gas purging for selected heating applications.

Loading capacity. The gemstones may be loaded into the muffle in two modes: Mode-A. Using one crucible OD=70, H-100 mm holding about 3,300 cts. corundum. Other gemstones can be loaded to 4,000 cts depending on their density.
Mode-B. unique feature of the V1200-80 furnace is the ability to load small quantities of gemstones in 6 alumina dishes which are inserted into the crucible and subsequently into the muffle for heating. Each dish is OD=50mm H=16mm where 200-250 cts of gemstones can be loaded. Gemstones from different localities, or stones with different features may be heated together on the same time, under the same heating parameters without been mixed or contaminated each other. Likewise, fluxed and unfluxed stones may be placed in different dishes. Loading these stones in this method is particularly useful in research heating projects where contamination of he load must be avoided and precision is required.

Mode-A. Loading a single crucible (3100-3500 cts)

Mode-B. Loading with ceramic dishes (1900-2000 cts)

Consumables and life expectancy of the parts


Electricity consumption depends on many factors. On a typical heating process the furnace requires about 900 Watts to maintain 1200oC furnace soaking temperature for several hours.


A typical muffle tube lasts usually more than 50 heating runs if properly sealed at soaking furnace temperature about 1200oC in air; life expectancy is reduced proportionally as the furnace temperature is increased; about 20 runs in vacuum at soaking 1200oC for 2 hours
CRUCIBLE AND OTHER TECHNICAL CERAMICS The life expectancy of technical ceramics (crucibles, disk, dish) depends on many factors (heating up rate, cooling down rate, soaking temperature, time are soaking temperature, type of fluxes and other additives is used. Technical ceramics usually last 10+ runs at soaking 1200oC for several hours; less if fluxes are used in the heating process.
THERMOCOUPLE K-type thermocouple assembly lasts over 300+ runs at 1200oC furnace operating temperature.
HEATING ELEMENTS The life expectancy of the heating wire depends on many factors which should be carefully considered. No guarantee is made by any heating wire manufacturer. The heater wire cannot be replaced as it is embedded in the ceramic insulation. If the life expectancy of the heater is consumed, then the heater module should be replaced. Life expectancy of the wire is more than 5,000 of hours of operation at 1200oC.

Technical specifications Comparison features between all Gemlab models



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