The Valfonta 253 steam ejector is a steam jet injector designed for heating liquids in installations external to the tank. Unlike model 252 (which is installed submerged), this equipment is mounted on the external piping, creating a forced recirculation circuit.
It uses the kinetic energy of steam to draw liquid from the tank, intimately mix it with steam (releasing latent heat), and pump it back to the tank at a higher temperature. This process generates constant fluid recirculation, ensuring homogeneous mixing and thermal uniformity throughout the volume, preventing temperature stratification. With no moving parts, it offers quiet, vibration-free operation with zero maintenance, making it a robust and economical alternative to conventional heat exchangers.
- Heat Output Range: Available in 5 construction sizes to meet different thermal needs. Nominal outputs (calculated with saturated steam at 3 bar) are:
- Model No. 1: 50,000 Kcal/hour.
- Model No. 2: 100,000 Kcal/hour.
- Model No. 3: 200,000 Kcal/hour.
- Model No. 4: 300,000 Kcal/hour.
- Model No. 5: 500,000 Kcal/hour.
- Design Conditions:
- Nominal Pressure: Body designed for PN16.
- Maximum Working Pressure: Can withstand up to 16 bar g.
- Maximum Allowable Temperature: Up to 200°C.
- Construction Materials:
- Body: Available in Ductile Iron GGG40.3 (Standard), Bronze RG10 or Stainless Steel A351 CF3M (for corrosive or food fluids).
- Nozzle (Critical Internal Part): Manufactured in Bronze RG10 (Standard), Stainless Steel A351 CF3M or Monel (for maximum resistance to erosion and corrosion).
- Connections: Standard by DIN PN16 Flanges.
- Bore Sizes (Steam / Liquid):
- Steam pipe bore (a): From 40 mm (Model 1) up to 70 mm (Model 5).
- Liquid pipe bore (c): From 40 mm (Model 1) up to 120 mm (Model 5).
Operation is based on the Venturi Effect and the thermodynamics of fluids, operating in a continuous suction-heating-delivery cycle:
- Injection: Steam is introduced under pressure through the axial inlet of the reheater (marked as 'a').
- Depression and Suction: As the steam accelerates through the nozzle, a low-pressure zone (vacuum) is generated in the mixing chamber. This draws cold liquid from the bottom of the tank through the side connection (marked as 'c').
- Thermal Exchange: Inside the body, steam mixes directly with the liquid, condensing and instantly transferring its heat.
- Discharge and Recirculation: The resulting mixture, now hot and at higher pressure, is delivered by the outlet to the top of the tank, generating a current that stirs the entire content.
This model is designed for installations where the equipment cannot or should not be inside the tank:
- Installation Scheme: Mounted externally to the tank in a bypass or loop configuration. The suction line connects to the base of the tank and the discharge returns to the top, creating a closed cycle.
- Piping Sizing: The manufacturer expressly recommends that if the installation pipelines are of great length, pipes of a larger diameter than the nominal bores of the reheater should be used to avoid pressure losses that reduce performance.
- Typical Applications:
- Water heating for barrel, tank and drum washing.
- Installations in pipes exposed to frost risk (freeze protection).
- Processes in breweries, sugar mills, dyeing plants and the general chemical industry where rapid liquid heating is required.
