Patent ID: 9657598
Date: 2017-05-23
CPC Classifications: F01K,F22B

Claim:
1. A method of generating immediate and thereafter continuous steam in an auxiliary steam generating system backing-up a main steam system having a main steam temperature and pressure, the auxiliary steam generating system comprising a steam accumulator, a steam outlet connected to said steam accumulator, an outlet valve at said steam outlet connected to the main steam system, and a quick response steam generator unit connected to said steam accumulator, said method comprising the following steps: providing a latent steam in said steam accumulator at an idle pressure and a temperature higher than that of the main steam system; opening said outlet valve when the immediate and thereafter continuous steam is requested from the main steam system, to allow the latent steam in said steam accumulator to exit through said steam outlet towards the main steam system, the latent steam becoming the immediate and thereafter continuous steam; feeding water to said steam generator unit, wherein water fed to said steam generator unit is fed from said steam accumulator; heating the water fed to said steam generator unit that exits the steam generator unit as liquid-state water that flashes and becomes latent steam in the accumulator, the latent steam exiting through said steam outlet as the immediate and thereafter continuous steam and the steam generator unit comprises at least one coil boiler comprising coil-shaped pipes in which the water fed is circulated and from 3% to 30% by mass of the water fed to the at least one coil boiler exits as steam; and before said latent steam has entirely exited said steam accumulator as the immediate and thereafter continuous steam, controlling the steam flow rate through said steam outlet to maintain the steam flow rate at a value which is essentially not greater than the steam flow rate from said steam generator unit to said steam accumulator; thereby said auxiliary steam generating system generates immediate and thereafter continuous steam from an initial steam generator unit cold condition due to said steam accumulator providing steam at said steam outlet while said steam generator unit heats the water fed therein, and wherein the steam generator unit generates steam from the initial steam generator unit cold condition to a full steam production mode of the steam generator unit in 5 to 10 minutes and to maintain the main steam system at the main steam temperature and pressure.