System and method for softening high-salinity water via self-induced calcium bicarbonate crystallization in fluidized bed

A system for softening saline water via self-induced calcium bicarbonate crystallization in fluidized bed, comprising:

• a fluidized bed-based crystallization-softening reaction unit;
• a water feeding unit;
• a dosing unit;
• and
• a regulation unit;
• wherein the fluidized bed-based crystallization-softening reaction unit is configured to induce a crystallization reaction to soften a saline water;
• the water feeding unit is configured to supply the saline water to the fluidized bed-based crystallization-softening reaction unit;
• the dosing unit is configured to supply a pH regulating agent to the fluidized bed-based crystallization-softening reaction unit;
• the regulation unit is configured to perform reflux replenishment for the fluidized bed-based crystallization-softening reaction unit and recover escaping crystals;
• the fluidized bed-based crystallization-softening reaction unit comprises a crystallization-softening fluidized bed reactor;
• the crystallization-softening fluidized bed reactor comprises a mixing module, a reaction module, a transition module and a clarification module sequentially connected from bottom to top;
• wherein
• the mixing module has an inverted conical shape, the reaction module has a cylindrical shape, the transition module has an inverted truncated-cone shape, and the clarification module has a cylindrical shape;
• the clarification module is connected to the mixing module through a return pipe;
• an end of the return pipe adjacent to the clarification module is provided with a return valve;
• and the return pipe is further provided with a return pump and a first online pressure gauge;
• and the return pipe is provided with a check valve adjacent to the mixing module;
• a bottom of the mixing module is connected to a crystal discharge pipe;
• the crystal discharge pipe is provided with a crystal discharge valve adjacent to the mixing module;
• and the mixing module is provided with a second online pressure gauge;
• a side wall of the reaction module is connected to a liquid discharge pipe;
• the liquid discharge pipe is provided with a liquid discharge valve adjacent to the reaction module;
• the liquid discharge pipe is further provided with a liquid discharge pump;
• and the reaction module is provided with an online pH meter, wherein the online pH meter is provided at a bottom end of the reaction module;
• an upper end of a side wall of the clarification module or a top of the clarification module is connected to an outlet pipe;
• and the clarification module is provided with an online turbidity meter;
• a diameter of the clarification module is greater than a diameter of the reaction module;
• a lower end of the clarification module is connected to a lower end of the mixing module through the return pipe;
• and
• the online turbidity meter is provided at the lower end of the clarification module at a position not higher than a connection point of the return pipe to the clarification module;
• the water feeding unit comprises a water feeding tank;
• a bottom of the water feeding tank is connected to the mixing module through an inlet pipe;
• the inlet pipe is provided with an inlet valve adjacent to the water feeding tank;
• and the inlet pipe is further provided with an inlet pump and a third online pressure gauge;
• the dosing unit comprises a dosing tank;
• a bottom of the dosing tank is connected to the mixing module through a dosing pipe;
• the dosing pipe is provided with a dosing valve adjacent to the dosing tank;
• and the dosing pipe is further provided with a dosing pump and a fourth online pressure gauge;
• the regulation unit comprises a secondary sedimentation tank;
• a bottom of the secondary sedimentation tank is connected to an upper end of a side wall of the water feeding tank or a top of the water feeding tank through a crystal supply pipe;
• the crystal supply pipe is provided with a crystal supply valve adjacent to the secondary sedimentation tank;
• and the crystal supply pipe is further provided with a crystal supply pump;
• a middle of a side wall of the secondary sedimentation tank is connected to the return pipe through a water supply pipe;
• and the water supply pipe is provided with a water supply valve adjacent to the secondary sedimentation tank;
• a top of the secondary sedimentation tank is connected to the reaction module through the liquid discharge pipe, and is connected to the clarification module through the outlet pipe;
• and
• an upper end of the side wall of the secondary sedimentation tank is provided with a supernatant overflow port.