Quartz Immersion Infrared Heater Lamp For Chemical Liquid Clean Heating

Quartz Immersion Infrared Lamp

Substrate Properties: Made of high purity transparent quartz glass (SiO₂ content ≥ 99.9%), which is extremely chemically stable. Except for hydrofluoric acid (HF) and hot concentrated phosphoric acid, it resists corrosion from almost all acid and alkali media, does not release metal ions, and thus ensures the purity of the process liquid.

Heating Mechanism: The filament (tungsten alloy wire, reaching a filament temperature of ~2000 °C) generates Joule heat when energised, causing its temperature to rise rapidly. The quartz inner wall is heated primarily by infrared radiation from the hot filament. Quartz has high transmittance and absorptivity in the infrared band; after absorbing the radiative energy, the lamp wall heats up uniformly. Subsequently, the outer surface of the quartz lamp transfers the vast majority of the heat to the bulk liquid via forced convection (supplemented by conduction through the quartz wall itself), thereby achieving uniform temperature rise of the liquid in the reactor.

Advantages of this heat transfer path:

Radiation stage – infrared radiation does not require a medium and can directly penetrate the air gap inside the lamp to reach the quartz wall, ensuring fast thermal response and preventing local overheating of the filament.

Convection stage – liquid flow enhances the convective heat transfer coefficient at the lamp wall surface; the heat is “carried away” by the liquid rather than accumulating on the wall, significantly reducing the wall temperature gradient and prolonging the quartz lamp’s service life.

Overall effect – the combined radiation convection two stage heat transfer ensures a high heating rate while avoiding local overheating and coking problems commonly associated with traditional metal heating rods, which suffer from large surface thermal resistance.

Thermal Shock Resistance: Quartz glass has an extremely low coefficient of thermal expansion (≈ 0.55 × 10⁻⁶/°C). It can withstand severe thermal cycling (e.g., rapid changes from ambient temperature to 800 °C) without cracking, greatly enhancing reliability under frequent start stop operating conditions.

Structural Design Features (Twin lamp Quartz Immersion Infrared Lamp)

Twin Tube Infrared Radiant Heat Lamps are widely used in high-efficient industrial fast heating applications. The IR lamp is made of quartz double tube. The heating filament is tungsten alloy material. We have 23×11mm and 33×15mm quartz twin tube for different customers. The total length of twin tube IR lamp can be up to 6.0 meter. 

Fast response – 1 second response time, rapid heating rate, filament temperature up to 2000 °C.

High electrical insulation – withstands several thousand volts, far exceeding general industrial safety standards.

Centred filament positioning – the twin tube arrangement keeps the heating wire geometrically centred, resulting in a symmetric thermal field and preventing local hot spots.

Supplementary recommendation regarding the quartz outer protective sleeve

Under extreme service conditions (e.g., high-hardness water, solutions prone to salt crystallisation, or strong flow-scouring environments), a removable quartz protective sleeve can be added over the main heating lamp as a barrier.

However, note that the double quartz wall construction increases thermal resistance, reducing overall thermal efficiency by approximately 5 %–10 %.

Under normal operating conditions, the outer wall of the twin tube quartz lamp itself already provides excellent corrosion resistance and fouling resistance; a protective sleeve is generally not required. Nevertheless, care must be taken to ensure that the lamp is not subjected to any external mechanical force that might cause breakage.

Engineering Installation Parameters (12 units IR lamp Ring Arrangement)

Electrical Wiring and Safety Interlock Essentials

Three-phase load balancing

The 12 heating lamps are evenly distributed among the three phases, with 4 lamps per phase. Depending on the rated voltage of the heating lamps and the on site power supply conditions, choose either:

Star (Y) connection – suitable for lamps rated at 220 V with a 380 V line to line supply.

Delta (Δ) connection – suitable for lamps rated at 380 V with a 380 V line to line supply.

Dry fire prevention interlock (mandatory)

A level switch (float type or capacitive) must be installed in the reactor and hard wired into the heating main circuit.

When the liquid level drops below the top of the 600 mm heating zone, all heating lamps must be automatically disconnected.

It is strictly forbidden to energise the lamps without liquid coverage – dry firing will cause the quartz wall to soften, deform, or even melt instantly due to excessive temperature.

Lead out method
The power leads exit vertically upward from the cold zone and are routed through ceramic terminal blocks (withstand temperature ≥ 1000 °C, high insulation resistance). This effectively prevents condensate from flowing back along the wires to the connection terminals.