Pit type high temperature furnace


  • Pit type sealed retort furnaces are of a cylindrical design vertically erected with a positive sealing mechanism on top in order to contain and preserve heat and atmosphere during a process cycle.
  • The job or charge is loaded into a retort which functions as the chamber of the furnace and the retort is heated externally electrically.
  • Pit furnaces like these are used in general engineering and metallurgical applications for carburizing, nitriding, carbonitriding, nitrocarburizing, hardening, tempering, annealing and also in process industries like coal tar processing, separation of titanium and magnesium from ore etc. .
  • Special processes such as aluminium and titanium heat treatment can also be done.
  • In process industries these furnaces can also be used in high pressure applications with temperatures from 800°C to 1200°C and pressure ranging from 400mm water column to 9 bar.
  • These are often laid in a pit to make most of the space available and charges can be loaded and unloaded easily.
  • These are manufactured considering working controlled atmospheres with inlets for diffusion and distribution of cracked ammonia, hydrogen, LPG, methanol, argon, nitrogen and other process fluids.
  • Therelek manufactures and sets up complete automated process plants also.
  • Temperature control, fluid dissociation, gas penetration and dosing can all be taken up for automated operation.
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Temperature Range :

Upto 1100°C

Standard Applications :

Annealing / Annealing under protective atmosphere, Isothermal Annealing, Carbonitriding, Carburizing, Decarb annealing, Gas Nitriding, Hardening, Stress Relieving, Wire annealing, Ferritic Nitro Carburizing, Normalizing, Case Hardening

Retort MOC :

AISI 304 / AISI 310 / AISI 316 / AISI 330 / Inconel 600

Insulation :

Vacuum Formed Ceramic Fibre Modules / Ceramic Fibre Blanket & Module / Refractory Brick Lining

Heating Media Options :

Electric / Gas Fired / Oil Fired

Heating Elements :

Nichrome Wire / Special Alloy Resistance Heating Wire

Furnace Classification :

Class 2 / Class 3

Instrumentation options :

Process Automation Equipment, Thyristor, Programmable Temperature Controller, Temperature Recorder, PLC, SCADA, HMI