Method and apparatus for improving steam dryness of steam injection boiler

A method for improving steam dryness of a steam injection boiler, comprising the steps of:

• setting dryness of wet saturated steam at an outlet of a steam injection boiler by a dryness raiser;
• and
• injecting the saturated steam together with gas generated by said dryness raiser into an oil layer in a sealed way;
• wherein said dryness raiser comprises:
• a combined spray head, a steam heating chamber, a combustion chamber, and a mixing chamber,
• wherein fuel oil and air are supplied into said combustion chamber by a high pressure fuel oil pump and an air compressor under control of an automatic control system of said dryness raiser,
• wherein fuel oil and air are combusted in said combustion chamber,
• wherein said wet saturated steam at said outlet of said boiler enters into said steam heating chamber of said dryness raiser (4) at a same time as said fuel oil and air are combusted,
• wherein said set saturated steam is heated in said steam heating chamber by heat created by combustion in said combustion chamber,
• wherein gas generated in said combustion chamber enters into said mixing chamber, and mixes in said mixing chamber with said wet saturated steam with increased dryness from said steam heating chamber, and
• wherein dryness of the wet saturated steam is further improved by controlling an amount of fuel oil with said automatic control system, dryness of said wet saturated steam being improved to 95%-100%, a temperature of a gas-steam mixture being controlled after mixing, said gas-steam mixture being injected into said oil layer through an steam injection string in a sealed way.