Water droplets collection device from airflow using electrostatic separators

Patent metadata

Field	Value
Publication number	US-12066258-B2
Application number	US-202017428237-A
Country	US
Kind code	B2
Filing date	Feb 4, 2020
Priority date	Feb 5, 2019
Publication date	Aug 20, 2024
Grant date	Aug 20, 2024

Abstract

There is provided a system and method for collecting water droplets from an airflow of a cooling tower (8) through condensation of water vapour using an electrostatic separator (20), wherein the electrostatic separator is a single unit electrostatic separator (20) or a multi-unit electrostatic separator. The method for water particles collection from the exhaust airflow of a cooling tower primarily comprises condensing water vapour into large water droplets. It is experimentally proved that electrostatic separation solves the problem of visible plume pollution, and blow down decreased since collected water flows back to the circulating water. Additionally, electrostatic separation results in small pressure drop of the cooling tower (8).

First claim

The invention claimed is:

1. A system for collecting water droplets from an airflow of a cooling tower through condensation of water vapor, the system comprising an electrostatic separator;
wherein the electrostatic separator is a single-unit electrostatic separator or a multi-unit electrostatic separator, and wherein the system for collecting water droplets from an airflow of a cooling tower further comprises:
a hot water tank;
water heaters to control a temperature of water within the hot water tank;
water pumps to pump cooled water back to the cooling tower;
an acrylic tube for water vapor condensation;
an annular water collection trough; and
a water collection tank.

2. The system of claim 1 , wherein the electrostatic separator comprises a collector electrode and a discharge electrode.

3. The system of claim 2 , wherein the collector electrode is made of tubular metal or aluminum.

4. The system of claim 2 , wherein the discharge electrode is made of iron.

5. The system of claim 2 , wherein the discharge electrode comprises a number of sharp points on a cross-section of the discharge electrode.

6. The system of claim 2 , wherein the discharge electrode comprises a barbed plate geometry.

7. The system of claim 2 , wherein the discharge electrode comprises a symmetric barbed plate discharge electrode (SBPDE) or an asymmetric barbed plate discharge electrode (ASBPDE).

8. The system of claim 1 , wherein single or multiple spray nozzles are used for producing water droplets for the single-unit electrostatic separator and the multi-unit electrostatic separator.

9. The system of claim 1 , wherein a diameter of the multi-unit electrostatic separator is 290 mm,
perforated acrylic plates are used to connect a plurality of collector electrodes together, and
an aluminium perforated plate is used as a ground connection.

10. A process for preventing evaporative losses occurring from a cooling tower by collecting water droplets from an airflow of the cooling tower, the process comprising the steps of:
controlling a temperature of the airflow using a water bath;
setting a temperature for a component using a heat exchanger, the component including an ultrasonic mist generator or a nozzle;
heating tap water in a water tank using immersion heaters;
pumping the heated tap water into the cooling tower;
removing heat from the heated tap water through evaporation;
producing water vapor and drift using the component;
passing the produced water vapor and drift through a fan located on top of the cooling tower;
allowing the produced water vapor and drift to enter an electrostatic separator;
charging the produced water vapor and drift,
wherein the produced water vapor and drift move towards a collector electrode due to an electric field force on passing through the electrostatic separator;

forming large water droplets on a wall of the collector electrode; and
allowing the formed large water droplets to flow down to a collected water tank.

11. A method for water particles collection from an exhaust airflow of a cooling tower using a single unit or a multi-unit electrostatic separator, wherein the method comprises:
heating tap water in a water tank using immersion heaters;
pumping the heated tap water into the cooling tower;
removing heat from the heated tap water through evaporation;
producing water vapor and drift;
passing the produced water vapor and drift through a fan located on top of the cooling tower;
allowing the produced water vapor and drift to enter the electrostatic separator;
charging the produced water vapor and drift;
wherein the produced water vapor and drift move to a collector electrode and condense to form large water droplets on a wall of the collector electrode; and

allowing the formed large water droplets to flow to a collector water tank.

12. The method of claim 11 , wherein efficiency of water collection from the exhaust airflow of the cooling tower depends on a state and size of the water vapor and drift.

13. The method of claim 11 , wherein efficiency of water collection is maximum when applied voltage is in a range of 17.5 kV to 20 kV, and corresponding power consumption is in a range of 6.1W to 13.5W.

Assignees

• Univ Khalifa Science & Technology

Inventors

• Al Alili Ali Rashed
• Alshehhi Mohamed Saeed
• Chaofan Wang

Classifications

• B03C3/017

  Combinations of electrostatic separation with other processes, not otherwise provided for · CPC title

• F28F2025/005

  Liquid collection; Liquid treatment; Liquid recirculation; Addition of make-up liquid · CPC title

• B03C2201/10

  Ionising electrode with two or more serrated ends or sides · CPC title

• B03C3/64

  synthetic resins · CPC title

• B03C3/49

  tubular · CPC title