Multi-stage evaporation system enhanced by a gravity-reduced field

Patent metadata

Field	Value
Publication number	US-10773182-B2
Application number	US-201816474557-A
Country	US
Kind code	B2
Filing date	Jan 11, 2018
Priority date	Jan 17, 2017
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

A multi-stage evaporation system enhanced by a gravity-reduced field consists of evaporation structures of multiple stages. There are three different operation modes, namely, a serial-connected air and parallel-connected solution mode, a serial-connected air and serial-connected solution mode, and a parallel-connected air and serial-connected solution mode. In the evaporation chambers, the solution directly contacts the air to transfer the heat and mass. The solution is sprayed on the rotating filling material, and is uniformly distributed under the action of the gravity-reduced field, which enhances the heat and mass transfer. The solution is gasified by absorbing the heat energy thereof. Meanwhile, the air can carry more water vapor after being heated by the solution and thus having an increased temperature, and take away the gasified solution, thereby achieving the purpose of evaporation.

First claim

What is claimed is:

1. A multi-stage evaporation system enhanced by a gravity-reduced field, comprising:
a liquid storage tank,
a preheater,
a primary evaporation structure,
a secondary evaporation structure,
a tertiary evaporation structure,
fans,
a feeding pump,
a circulation pump, and
a circulating liquid tank;
wherein the primary evaporation structure, the secondary evaporation structure, and the tertiary evaporation structure each comprise an evaporation chamber, a condensing regenerator, and a condensing dehumidifier, respectively;
a raw material solution in the liquid storage tank and a concentrated solution in the circulating liquid tank are mixed under an action of the feeding pump and the circulation pump, respectively, to form a mixed liquid;
the mixed liquid is equally divided into three streams, and the three streams of the mixed liquid, respectively, enter the condensing regenerator of the primary evaporation structure, the secondary evaporation structure, and the tertiary evaporation structure, respectively, for absorbing waste heat from circulating air;
after absorbing waste heat from the circulating air, the three streams of the mixed liquid are remixed and flow together to enter the preheater to be heated by steam;
after being heated by steam, the remixed liquid is equally divided into three preheated streams of the remixed liquid, and the three preheated streams of the remixed liquid, respectively, enter the evaporation chamber of the primary evaporation structure, the secondary evaporation structure, and the tertiary evaporation structure, respectively;
the remixed liquid directly contacts the circulating air in the evaporation chamber to transfer heat and mass to produce the concentrated solution, the concentrated solution flowing into the circulating liquid tank from the bottoms of the respective evaporation chambers;
the circulating air sequentially passes through the primary evaporation structure, the secondary evaporation structure, and the tertiary evaporation structure under an action of the fans to circulate, continuously; and
the evaporation chambers have a gravity-reduced field rotating structure.

2. The multi-stage evaporation system enhanced by a gravity-reduced field according to claim 1 , wherein flow rates of the mixed liquid streams, entering the respective condensing regenerators of the primary evaporation structure, the secondary evaporation structure, and the tertiary evaporation structure are controlled to be equal by valves; and
after the remixed liquid flows through the preheater, the mixed liquid is equally divided into the three preheated streams of the remixed liquid to enter the respective evaporating chambers of the primary evaporation structure, the secondary evaporation structure, and the tertiary evaporation structure by controlling the valves.

3. The multi-stage evaporation system enhanced by a gravity-reduced field according to claim 1 , wherein the fans blow the circulating air into the evaporation chambers from the bottoms of the evaporation chambers;
the circulating air is heated by the remixed liquid and takes away moisture in the remixed liquid, and exchanges heat with the remixed liquid in the condensing regenerators to recycle waste heat from the circulating air;
the circulating air then passes through the condensing dehumidifiers to exchange heat with cooling water, so as to make the circulating air return in a dehumidified state before entering the evaporation chambers; and
the circulating air enters an evaporation structure of a next stage to circulate.

4. The multi-stage evaporation system enhanced by a gravity-reduced field according to claim 3 , wherein the condensing dehumidifiers cool the circulating air by circulating cooling water;
after absorbing heat from the circulating air, the circulating cooling water is cooled by a cool water tower; and
the circulating cooling water is pumped into the condensing dehumidifiers again by the circulation pump to perform a circulating operation.

5. The multi-stage evaporation system enhanced by a gravity-reduced field according to claim 1 , wherein solution inlet pipes are provided on an upper portion of the evaporation chambers;
the solution inlet pipes are connected to the preheaters for an inflow of the remixed liquid into the respective evaporation chambers;
solution outlet pipes are provided on a respective bottom portion of each evaporation chamber;
the solution outlet pipes are connected to the circulating liquid tank for an outflow of the concentrated solution;
air inlet pipes are provided on a lower portion of the evaporation chambers;
the air inlet pipes are connected to the fans for an inflow of the circulating air;
air outlet pipes are provided on a top portion of the evaporation chambers; and
the air outlet pipes are connected to the condensing regenerators for an outflow of the circulating air and to recycle waste heat from the circulating air.

6. The multi-stage evaporation system enhanced by a gravity-reduced field according to claim 5 , wherein the evaporation chambers each have a respective spraying structure;
a plurality of spraying nozzles are provided at a respective roof of each evaporation chambers;
the mixed liquid sprayed by each spraying nozzle falls conically and angularly;
each of the solution inlet pipes extends into each of the evaporation chambers to form a circular support in proximity to the roof of the evaporation chambers; and
the spraying nozzles are uniformly arranged on the circular support.

7. The multi-stage evaporation system enhanced by a gravity-reduced field according to claim 6 , wherein a cylindrical filling material layer is fixed on a rotating shaft;
a flow of the remixed liquid that has been heated in the preheater is sprayed onto the cylindrical filling material layer through the spraying nozzles proximate to the respective roof of each evaporation chambers;
a motor drives the rotating shaft to rotate by a belt;
the cylindrical filling material layer is driven by the rotating shaft to rotate, so as to form the gravity-reduced field;
the remixed liquid is uniformly distributed in the cylindrical filling material layer, and tends to move along a radial direction from a middle to a periphery of the cylindrical filling material layer.

Assignees

• Nanjing University Of Technology

Inventors

• Ling Xiang
• Liu Weihong
• Li Yang
• Huang Xin
• Ke Tingfen

Classifications

• B01D1/14 Primary

  with heated gases or vapours {or liquids} in contact with the liquid · CPC title

• B01D1/26 Primary

  Multiple-effect evaporating · CPC title

• B01D3/08

  in rotating vessels; Atomisation on rotating discs ({B01D1/222} , B01D3/10 take precedence) · CPC title

• B01D1/222

  In rotating vessels; vessels with movable parts · CPC title

• B01D3/42

  Regulation; Control · CPC title