HTM System Purpose

Multiple process users need high-temperature heating. Direct firing each unit inefficient. Central HTM system vaporizes heat transfer fluid. Vapor pipes distribute to users where condensation releases latent heat. Condensate returns for revaporization maintaining closed loop.

Evaporator Design

Shell-and-tube configuration with combustion gas or hot oil shell-side heating tube bundle containing liquid HTM. Boiling generates vapor collecting in upper section. Vapor outlet connects to distribution header. Liquid level maintained for tube coverage. Circulation ensures adequate flow preventing tube dry-out.

Vapor Distribution

Insulated vapor pipes route high-temperature vapor to process heat exchangers. Pressure typically 5-30 bar depending on required temperature. Vapor condenses in user exchangers releasing heat. Condensate returns via gravity or pumps to evaporator.

Heat Transfer Medium

Dowtherm, Therminol, or specialty fluids with high-temperature stability. Selection based on required temperature range typically 200-400C. Fluid properties optimize heat transfer and vaporization characteristics. Chemical stability prevents degradation.

Operating Pressure

System pressure determines saturation temperature and heating capability. Higher pressure enables elevated temperatures for demanding processes. Design pressure per ASME codes with safety margin. Relief protection prevents overpressure.

Material Selection

Carbon steel or alloy construction depending on HTM temperature. Tube materials resist thermal cycling and fluid chemistry. Insulation maintains temperature reducing heat loss. Design accommodates thermal expansion.

Combustion System

Direct-fired evaporators use burners heating tubes. Forced or natural draft combustion. Fuel gas, oil, or dual-fuel capability. Combustion controls maintain proper firing rate matching vapor demand.

Level Control

Maintains liquid covering evaporator tubes preventing burnout. Low-level alarm and burner interlock protect equipment. High-level prevents carryover to vapor system. Automated makeup maintains inventory.

Applications

Chemical reactors requiring high-temperature heating, distillation reboilers, process heating in pharmaceuticals, polymer processing, specialty chemicals, and any operation needing distributed high-temperature thermal energy.

Condensate Return

Gravity or pumped return from users back to evaporator. Flash tanks accommodate pressure reduction from higher-pressure condensate. Proper return system design ensures continuous circulation.

Performance Benefits

Centralized heating more efficient than multiple fired heaters. Uniform temperature control through vapor pressure. Safety advantages of closed indirect heating. Simple proven thermal fluid technology.

Construction Standards

Evaporator per ASME Section VIII. Burner and combustion per applicable codes. Piping per B31.3 process piping. Materials for high-temperature service. Complete documentation with thermal calculations.

ERGIL HTM evaporator systems provide efficient centralized high-temperature heating through vapor distribution in chemical and process applications.