Liquid heating device

Abstract

The device for heating liquid generates steam, receives a fluid in liquid form at its inlet, and ejects the fluid heated up or in gaseous form at its outlet. The device includes a heater positioned inside a sleeve having a longitudinal axis. There is a scraper that fits onto the heater to scrape it the heater in case of movement along the longitudinal axis. A stopper fits snugly between the heater and the sleeve in order to stopper the passage. The scraper, the stopper, and a spring are configured so that an increase in pressure causes the scraper and the stopper to move along the longitudinal axis so that the stopper is shifted to a point where space between the heater and the sleeve allows fluid to pass, and a reduction in pressure causes a shift in the opposite direction by the spring.

1 . Device for heating a liquid, comprising:
 an inlet for receiving a fluid;   an outlet for ejecting the;   a heating means with a cylindrical external shape arranged within a sleeve having a longitudinal axis;   an element internally inserted onto the heating means and in space separating the heating means from an internal surface of the sleeve, said element creating disturbances in flow of fluid in said space, said element being comprised of a scraper engaging the heating means so as to scrape the heating means during a movement along said longitudinal axis;   a stopper, closely fitting between the heating means and the sleeve, said stopper having a closed position of a passage in at least one position of said stopper; and   yet a spring, said scraper, said stopper and said spring being configured such that an increase of pressure of entering fluid generates a movement along said longitudinal axis of the scraper and the stopper so as to move said stopper to a point where space between the heating means and the sleeve allows said fluid to pass, wherein a decrease in the pressure of the entering fluid generates a displacement in the opposite direction thanks to said spring.   
     
     
         2 . Device according to  claim 1 , wherein said scraper scrapes both an external surface of the heating means and the internal surface of the sleeve. 
     
     
         3 . Device according to  claim 2 , wherein said scraper has a helical shape with non-joining spires. 
     
     
         4 . Device according to  claim 1 , wherein said stopper has a helical shape with joining spires. 
     
     
         5 . Device according to  claim 1 , wherein said scraper and said stopper are two portions of one single part. 
     
     
         6 . Device according to  claim 1 , wherein said scraper, said stopper and said spring are three portions of one single part. 
     
     
         7 . Device according to  claim 1 , wherein at least one of said scraper, said stopper and said spring has a cross-section having a shape of a circular crown in a plane perpendicular to said longitudinal axis. 
     
     
         8 . Device according to  claim 1 , wherein at least one of said scraper, said stopper and said spring has a cross-section having a shape of a rectangular or square crown in a plane perpendicular to said longitudinal axis. 
     
     
         9 . Device according to  claim 1 , wherein said scraper comprised of a helical winding of an element having a rectangular or square cross-section. 
     
     
         10 . Method for automatically cleaning a heater having a cylindrical external shape using a device according to  claim 1 , said method comprising the following steps:
 supplying fluid in liquid form;   heating said fluid to vaporization, increasing volume of fluid on an inlet side of said device;   displacement along the longitudinal axis of the stopper and the scraper, producing a first scraping of the heating means, until fluid passes to the outlet, generating a pressure drop at the inlet; and   displacement in The an opposite direction of the stopper, until said stopper is closed, generating a second scraping of the heating means.