System and method for using a pulse flow circulation for algae cultivation

Patent metadata

Field	Value
Publication number	US-2016251608-A1
Application number	US-201615149717-A
Country	US
Kind code	A1
Filing date	May 9, 2016
Priority date	Jul 25, 2011
Publication date	Sep 1, 2016
Grant date	—

Abstract

A device for generating a pulsed flow in a channel containing a circulating algal culture can include a plate that is pivotably mounted on the channel and an activator. A pulsed flow is generated in the channel by first positioning the plate to impede the flow of circulating algal culture and then rotating the plate to a submerged position. The pulsed flow can be employed to counteract the negative effects of bio-fouling on algae cultivation equipment. In another arrangement, a device for generating a pulsed flow in a sloped raceway that is in fluid communication with a sump can include a gate. In different embodiments, the gate can operate as a so-called “pinch gate” or as a so-called “overflow gate.” In another aspect, a variable rate pump, such as a centrifugal pump, a screw pump or an airlift pump, is described for establishing a pulsed flow in a channel.

First claim

What is claimed is:

1 . A device for generating a pulsed flow in a channel containing a circulating algal culture, the device comprising:
a plate positioned in the channel and having a first end and a second end with the first end pivotably mounted on the channel, wherein the channel has a defined level fluid surface area; an activator coupled with the plate for selectively rotating the plate about a pivot axis from a first position to a second position, in accordance with a predetermined schedule, to generate a pulsed flow in the channel; and a timer connected with the activator for indicating when the plate is to be rotated for compliance with the predetermined schedule to increase the fluid surface area in each pulsed flow above the level fluid surface area to provide a greater culture productivity by up to 40%.

2 . The device recited in claim 1 wherein the activator comprises a rotary actuator.

3 . The device recited in claim 1 wherein the second end of the plate is positioned above the algal culture for a preselected period of time to establish a preselected height differential between algal culture on opposing sides of the plate.

4 . The device recited in claim 1 wherein the channel is a pond channel.

5 . The device recited in claim 1 wherein the channel is a sloped raceway.

6 . The device recited in claim 1 wherein the second end of the plate is positioned above the algal culture in the first position and the second end of the plate is submerged in the algal culture in the second position.

7 . The device recited in claim 1 wherein the channel is formed with a bottom and wherein the plate is rotated toward the channel bottom to generate a pulsed flow by pinching algal culture between the plate and the channel bottom.

8 . The device recited in claim 1 wherein the channel is formed with a bottom and wherein the plate is rotated away from the channel bottom to generate a pulsed flow by pushing algal culture between the plate and the channel bottom.

9 . The device recited in claim 1 wherein the plate has a width, the channel has a width, and the plate width is less than the channel width to allow algal culture to bypass the plate.

10 . A device for generating a pulsed flow in a channel containing a circulating algal culture, wherein the channel has a defined level fluid surface area, the device comprising:
a pump positioned for interacting with the algal culture; an activator coupled to the pump for selectively operating the pump in accordance with a predetermined schedule to increase the flow rate in the channel from a first flow rate f 1 , established for circulating the algal culture through the channel, to a second flow rate f 2 with f 2 >f 1 to generate a pulsed flow in the channel; and a timer connected with the activator for indicating when the pump is to be operated for compliance with the predetermined schedule to increase the fluid surface area in each pulsed flow above the level fluid surface area to provide a greater culture productivity by up to 40%.

11 . The device recited in claim 10 wherein the pump is a variable rate pump.

12 . The device recited in claim 11 wherein the ratio of flow rates (f 2 :f 1 ) is in a range between 2:1 and 10:1.

13 . The device recited in claim 11 wherein the pump is selected from the group of pumps consisting of a centrifugal pump, a screw pump, a propeller pump, a jet pump and an airlift pump.

14 . A device for generating a pulsed flow in a channel containing a circulating algal culture to increase exposed algal surface area and improve productivity, wherein the channel has a defined level fluid surface area, the device comprising:
a plate positioned in the channel and having a first end and a second end with the first end pivotably mounted; a trigger rotatable about a pivot point; an activator coupled with the trigger for selectively rotating the trigger in accordance with a predetermined schedule from a first position wherein the trigger holds the plate in a closed position to a second position in which the plate is released into an open position to generate a pulsed flow in a channel; and a timer connected with the activator for indicating when the trigger is to be rotated for compliance with the predetermined schedule to increase the fluid surface area in each pulsed flow above the level fluid surface area to provide a greater culture productivity by up to 40%.

15 . The device recited in claim 14 wherein the channel is a pond channel.

16 . The device recited in claim 14 wherein the channel is a sloped raceway.

17 . The device recited in claim 14 wherein the second end of the plate is positioned above the algal culture in the first position and the second end of the plate is submerged in the algal culture in the second position.

18 . The device recited in claim 14 wherein the channel is formed with a bottom and wherein the plate is rotated toward the channel bottom to generate a pulsed flow by pinching algal culture between the plate and the channel bottom.

19 . The device recited in claim 14 wherein the channel is formed with a bottom and wherein the plate is rotated away from the channel bottom to generate a pulsed flow by pushing algal culture between the plate and the channel bottom.

20 . The device recited in claim 14 wherein the plate has a width, the channel has a width, and the plate width is less than the channel width to allow algal culture to bypass the plate.

Assignees

• General Atomics

Inventors

• Hazlebeck David A
• Zhang Jiping
• Downey Kevin W
• Wu Xiaoxi

Classifications

• C12N1/12

  Unicellular algae; Culture media therefor (as new plants A01H13/00) · CPC title

• A01G33/00

  Cultivation of seaweed {or algae} · CPC title

• C12M41/44

  of volume or liquid level · CPC title

• C12M23/18

  Open ponds; Greenhouse type or underground installations · CPC title

• C12M41/48

  Automatic or computerized control (automatic analysis G01N35/00) · CPC title