Total heat energy recovery system for furnace-process phosphoric acid

A total heat energy recovery system for furnace-process phosphoric acid, comprising a phosphorus burning tower (1), the lower part of the phosphorus burning tower (1) is provided with an air inlet through which yellow phosphorus and air enter the phosphorus burning tower (1);

• soft water enters the phosphorus burning tower (1) from an upper head at the top of the phosphorus burning tower (1), one end of a gas guide tube (1-1) is connected to the phosphorus burning tower (1), and the other end of the gas guide tube (1-1) communicates with the top of a hydration tower (2);
• after being heated by the gas guide tube (1-1), the soft water passes through a pipeline and is mixed with part of steam to be conveyed into a deaerator (7), and a water outlet of the deaerator (7) communicates with a soft water inlet of an economizer (8) through a feedwater pump (13);
• a gas outlet of the hydration tower (2) is connected to a gas inlet of an absorption tower (3), a polyphosphoric acid outlet of the hydration tower (2) is connected to a polyphosphoric acid inlet of the economizer (8) through a first phosphoric acid pump (10), a soft water outlet of the economizer (8) communicates with a steam pocket of the phosphorus burning tower through a pipeline, a steam outlet of the steam pocket of the phosphorus burning tower communicates with a steam inlet of a steam manifold, and the steam is discharged from a steam outlet of the steam manifold;
• a polyphosphoric acid outlet of the economizer (8) communicates with a polyphosphoric acid inlet of the hydration tower;
• a phosphoric acid outlet of the absorption tower (3) respectively communicates with a phosphoric acid inlet of the hydration tower (2) and a phosphoric acid inlet of the absorption tower (3) through a second phosphoric acid pump (11), and a gas outlet of the absorption tower (3) communicates with a gas inlet end of a Venturi tube (4);
• a gas outlet of the Venturi tube (4) communicates with a gas inlet of a demister (5), and a gas outlet of the demister (5) discharges end gas through an induced draft fan (6);
• a dilute phosphoric acid outlet of the Venturi tube (4) communicates with a liquid inlet of a dilute acid circulating tank (9), and a liquid outlet of the dilute acid circulating tank (9) communicates with a liquid inlet of the Venturi tube (4) through a third phosphoric acid pump (12);
• the soft water enters the upper head of the phosphorus burning tower (1) and the gas guide tube (1-1) to be heated, then enters the deaerator (7), is pumped into the economizer (8) by the feedwater pump (13) to recover sensible heat of gas and heat of hydration of phosphorus pentoxide which are brought into the hydration tower by the phosphorus burning tower gas, and then enters the steam pocket of the phosphorus burning tower (1) to serve as boiler feed water, thus generating steam with different pressure grades by recovering heat of reaction of yellow phosphorous of the phosphorus burning tower (1).