TMFFA-50K-G 50 kg Gas-Fired Tilting Crucible Furnace

TMFFA-50K-G is a 50 kg gas-fired, hydraulically tilted crucible furnace we designed for melting aluminium and its alloys; it is the gas-fired sibling of the electric TMFFA-50K-E. The chamber is built around a TP 400 class crucible with pouring spout. What sets it apart is the gas path: combustion gas leaves the chamber at the top, descends inside the wall and connects to a fixed station on the floor that does not tilt with the furnace.

Gas path: out at the top, down inside the wall

The burner fires tangentially into the chamber at the level of the crucible base. The flame wraps the crucible pedestal, then the combustion gas spirals up around the crucible and sweeps it over its full height. The gas leaves the chamber at the very top, so no gas can short-circuit from the burner to the flue without heating the upper half of the crucible. The exit sits in the last wall segment before the burner in flow direction; the gas travels almost a full turn around the crucible before it gets there.

From there the gas enters a down-channel built inside the wall. The channel lies between chamber and shell and is separated from the chamber by a precast high-alumina (LCC 70% Al₂O₃) baffle; both faces of the baffle are hot, so it needs no insulation. Behind the channel is lightweight castable, 1260 °C board and microporous board, which keeps the steel of the channel pocket in the shell cool. The gas descends inside the channel and leaves under the body. From outside there is no flue duct leaning on the shell or cutting through the platform; the platform floor is continuous.

A flue that does not tilt: fixed connection station

On tilting gas-fired crucible furnaces the flue, recuperator and fan are usually hung on the furnace and tilt with it. Not on this one. The duct under the platform ends behind the furnace in a bell. With the furnace upright, the bell sits on the receiving box of a fixed connection station standing on the floor: the lip of the box enters the labyrinth skirt of the bell, and the flue draught only pulls air in through the gap; no gas comes out. The recuperator, lined stack, combustion air fan and air butterfly valve are on this station, i.e. on the floor, and do not tilt.

Combustion air is connected the same way: air heated in the recuperator comes through a fixed pipe to a connection flange at floor level; the pipe from the burner, which tilts with the furnace, sits on this flange from above, with a ceramic rope seal between the two flanges. When tilting starts, bell and air flange lift almost vertically and separate from the station; no tilting part touches a fixed part through the whole stroke. This was checked in the 3D model with a 0–90° tilting sweep.

What this gives:

• Less tilting mass and a lower swept height; the hydraulic cylinder does not carry a hot stack and recuperator.
• No flexible hose or rotary joint for hot gas or hot air.
• A clean platform with easy access to the crucible.
• Recuperator and fan on the floor, easy to service.

Interlock

The burner is shut off before tilting starts. When the furnace is back on its stop and the "connection seated" switch is made, the furnace is pre-purged and only then released for ignition. Air valve position and the air pressure switch are part of this sequence.

Burner and combustion air

The standard burner is a BIO 50 class gas burner (Kromschröder), 40 kW. Combustion air is preheated by the flue gas in the recuperator on the fixed station. Gas/air ratio is held by a ratio regulator and air flow is set by a motorised butterfly valve; an air pressure switch and flame supervision are standard. The burner zone is protected by 1650 °C class LCC 70% Al₂O₃ castable.

Tilting and pouring

Tilting is hydraulic, with the tilting axis at the tap-out, so the pouring point does not move while tilting. The lid is opened by a hydraulic cylinder. The crucible mouth is close to floor level, so the operator works from the floor; no platform is needed.

Refractory and insulation

The floor is multi-layer: LCC 60% alumina castable, 1260 °C class board and microporous board. Thicknesses are chosen so that the microporous layer stays below its class limit; on the 08-G master model the floor steel is ≈133 °C by calculation. If the crucible cracks, molten metal is drained out through a channel in the floor refractory. The chamber has control and over-temperature (limit) thermocouples plus a spare thermocouple port.

Design checked by calculation

The position of the gas exit was compared with the thermal cycle model: on the 08-G, moving the exit from beside the burner to the top cut melting time from ≈84 to ≈74.5 minutes and consumption from ≈68.5 to ≈61 Nm³/t. The flame path and heat flux on the crucible were studied with flow analysis (CFD), which confirmed the burner direction.

Technical data

Technical values come from our design, thermal and flow (CFD) calculations; melting time and consumption are the cycle model of the 08-G master model adapted to each size. Final values are confirmed at project stage. Images are produced from the 3D design of the product.

We manufacture the furnace together with the chamber, burner and gas train, the fixed connection station (recuperator, fan, stack) and the control panel, and install and commission it on site. We work with you on other capacities, burner and crucible choice at quotation stage.

For price and lead time, use the Request a Quote button or call +90 533 945 27 94.

Tags: TMFFA-50K-G, 50 kg gas furnace, gas-fired tilting furnace, gas crucible furnace, crucible melting furnace, aluminium melting furnace, recuperative crucible furnace