Device and method for increasing solid holdup in reaction crystallizer

Patent metadata

Field	Value
Publication number	US-11896946-B2
Application number	US-202017051735-A
Country	US
Kind code	B2
Filing date	Jul 7, 2020
Priority date	Sep 11, 2019
Publication date	Feb 13, 2024
Grant date	Feb 13, 2024

Abstract

A device and method for increasing solid holdup in a reaction crystallizer are disclosed. The device includes a discharge pipe, a clear liquid pipe, a clear liquid tank and a gas collecting pipe. A lower end of the discharge pipe is inserted into the crystallizer below the liquid level, while that of the clear liquid pipe is inserted into the clear liquid tank below the liquid level. By using the gas collecting pipe, the reaction crystallizer and the clear liquid tank are communicated all the time. When feeding, a liquid-solid mixture in the crystallizer automatically enters the discharge pipe and flows upward slowly therein, during which solid particles gradually settle down and automatically fall back into the crystallizer while the clear liquid keeps on flowing upward, enters the clear liquid pipe and thereby flows into the clear liquid tank. The clear liquid tank maintains a constant liquid level via overflowing.

First claim

What is claimed is:

1. 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.

2. The device of claim 1 , wherein an inverted cone-shaped expansion segment is disposed on an upper portion of the discharge pipe to reduce a liquid velocity and improve liquid-solid separation efficiency; and
wherein a cone angle of the inverted cone-shaped segment is greater than a reposing angle of crystal particles to prevent blockage by accumulation.

3. The device of claim 1 , wherein the gas collecting pipe has a second end that connects to an input of an exhaust pump.

4. 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.

5. The method of claim 4 , wherein the clear liquid tank comprises an overflow port, and continuing pumping the feedstock solution into the reaction crystallizer until after the level of liquid in the clear liquid tank reaches the level of the overflow port.

6. The method of claim 4 , further comprising configuring an automatic control system to control the liquid level in the gas collecting pipe so that the liquid level in the gas collecting pipe remains above a level at which the reaction crystallizer and the clear liquid tank remain in liquid communication with one another.

7. The method of claim 4 , further comprising configuring the gas collecting pipe to have an expansion segment, and configuring an automatic control system to control the liquid level in the gas collecting pipe so that the liquid level remains in the expansion segment.

8. The method of claim 7 further comprising configuring the gas collecting pipe to have an expansion segment providing a valve above the expansion segment.

Assignees

• Qingdao Inst Bioenergy & Bioprocess Tech Cas
• Inst Process Eng Cas
• Qingdao Institute Of Bioenergy And Bioprocess Tech Chinese Academy Of Sciences & Institute Of Proces

Inventors

• Zhu Quanhong
• Huang Qingshan
• Xiao Hang
• Yang Chao

Classifications

• B01J19/06 Primary

  Solidifying liquids (making microcapsules B01J13/02) · CPC title

• B01D9/0059 Primary

  General arrangements of crystallisation plant, e.g. flow sheets · CPC title

• B01D9/0063

  Control or regulation (control per se G05) · CPC title

• B01D2009/0086

  Processes or apparatus therefor · CPC title

• B01D9/00 Primary

  Crystallisation (crystallisation directly from the vapour phase B01D7/02; making single crystals C30B {; crystallisation as part of the Bayer process also classified in C01F7/14}) · CPC title