Device and method for increasing solid holdup in reaction crystallizer

A device for increasing solid holdup in a reaction crystallizer, comprising:

• a reaction crystallizer;
• a clear liquid tank;
• a discharge pipe having a discharge pipe first end;
• wherein discharge pipe first end resides in the reaction crystallizer;
• a clear liquid pipe having a clear liquid pipe first end and a clear liquid pipe second end;
• wherein the clear liquid pipe first end resides in the clear liquid tank;
• wherein the clear liquid pipe second end connects to the discharge pipe at a first pipe junction at a first pipe junction height, thereby allowing fluid to flow between the discharge pipe and the clear liquid pipe;
• a gas collecting pipe having a gas collecting pipe lower end and a gas collecting pipe intermediate region at a gas collecting pipe intermediate region height;
• wherein gas collecting pipe lower end communicates with the discharge pipe;
• wherein the gas collecting pipe intermediate region height is above the first pipe junction height;
• and
• whereby, when a level of liquid residing in the reaction crystallizer is above the discharge pipe first end, a level of liquid in the clear liquid tank is above a level of the clear liquid pipe first end, and fluid fills the gas collecting pipe intermediate region, then the level of liquid residing in the reaction crystallizer and the level of liquid in the clear liquid tank attain the same level.

A method for increasing solid holdup in a reaction crystallizer, using a device for increasing solid holdup in a reaction crystallizer, the device comprising a discharge pipe;

• a clear liquid pipe;
• a gas collecting pipe;
• and a clear liquid tank;
• wherein the crystallizer and the clear liquid tank are communicated with each other by means of the discharge pipe and the clear liquid pipe to have same liquid level, comprising:
• providing a liquid-solid slurry comprising a liquid and solid particles in the reaction crystallizer;
• separating, in at least one of the reaction crystallizer and the discharge pipe, the liquid from the slurry, so that the solid particles fall back to the crystallizer and the liquid enters the clear liquid tank through the clear liquid pipe;
• and
• collecting, in the gas collecting pipe, a gas entering the discharge pipe and the clear liquid pipe.

A method for increasing solid holdup, in an apparatus comprising a reaction crystallizer;

• a clear liquid tank;
• a discharge pipe having a discharge pipe first end;
• wherein discharge pipe first end resides in the reaction crystallizer;
• a clear liquid pipe having a clear liquid pipe first end and a clear liquid pipe second end;
• wherein the clear liquid pipe first end resides in the clear liquid tank;
• wherein the clear liquid pipe second end connects to the discharge pipe at a first pipe junction at a first pipe junction height, thereby allowing fluid to flow between the discharge pipe and the clear liquid pipe;
• a gas collecting pipe having a gas collecting pipe lower end and a gas collecting pipe intermediate region at a gas collecting pipe intermediate region height;
• wherein gas collecting pipe lower end communicates with the discharge pipe;
• wherein the gas collecting pipe intermediate region height is above the first pipe junction height;
• and whereby, when a level of liquid residing in the reaction crystallizer is above the discharge pipe first end, a level of liquid in the clear liquid tank is above a level of the clear liquid pipe first end, and fluid fills the gas collecting pipe intermediate region, then the level of liquid residing in the reaction crystallizer and the level of liquid in the clear liquid tank attain the same level, the method comprising:
• adding a clear liquid to the clear liquid tank, so that the clear liquid pipe first end is submerged;
• adding liquid to the reaction crystallizer, so that the discharge pipe first end is submerged;
• exhausting gas from the gas collecting pipe, thereby sucking liquid up into the discharge pipe and sucking liquid up into the clear liquid pipe until the reaction crystallizer and the clear liquid tank are in liquid communication with one another;
• and
• pumping a feedstock solution into the reaction crystallizer, thereby resulting in flow into the discharge pipe and from the discharge pipe through the clear liquid pipe into the clear liquid tank.