Patent attributes
A compact gas fired steam generator comprises a water tank with designated steam separation zone, boiling zone and a solids separation zone, a burner for burning gaseous fuel with air for producing combustion products and a flat tubular type heat exchanger immersed in water in the water tank. The combustion products are passing through the heat exchanger in an indirect heat transfer relationship with water in boiling zone thereby boiling, circulating and evaporating the water in boiling zone and in an indirect heat transfer relationship with cold make up water passing upwardly through solids separation zone thereby preheating cold make up water and cooling combustion products and recovering latent heat and condensing moisture present in combustion products. The cooled combustion products are discharged to outdoors and the collected condensed moisture is discharged to drain.