|Sediment Sensors for Hydro Power |
|Sediment (Silt) Monitoring for Turbine Abrasion Protection in Run of River Hydro Power Plants Using LISST-Infinite and LISST-Hydro. |
LISST-Infinite (left) mounted immediately below the Francis runner at the San Francisco HPP, Ecuador. The turbid water is piped from the draft tube (right).
|In run of river power plants, severe erosion of turbine parts can occur due to sediments carried by rivers, despite the presence of desiltation chambers. The problem is severe in power plants that are sited in the steep terrains, e.g. the Himalayan topography, or in regions with rivers carrying large amounts of sediment, e.g. South America. |
|Turbines, wicket gates, valves etc. can suffer severe erosion if the size of suspended sediment grains is large. Convention has it that grains >200 microns cause the most severe damage. As a result, often desiltation efficiency is described in terms of the removal of such large grains. In fact, there is no sharp cut-off in size below which grains may cause no turbine erosion. Thus, a measurement of the full size distribution of suspended sediments is needed at all times.|
|The erosion of turbines in Hydro Power plants is known to be a severe problem in rivers that drain the Himalayas - covering India, China, Nepal, Bhutan and other countries of East Asia. In Europe, power plants in Switzerland and Norway also are subject to such erosion and wear. In South America, power plants in Colombia, Brazil, Ecuador, Chile and Bolivia suffer from the same damages.|
|Sequoia Scientific, Inc. has developed the world's first instrument system geared to the automated at-site MONITORING of the suspended sediment size distribution and concentration. Two different systems have been developed; one with and one without an auto-dilution system. These two systems are called LISST-Infinite and LISST-HYDRO, respectively. Using our basic laser diffraction technology the concentration and size distribution can be routinely and continuously monitored. |
LISST-HYDRO front panel
The LISST-HYDRO is quite similar to Sequoia's LISST-StreamSide instrument, but with the capability to talk to our LISST-Infinite Monitor software for displaying real-time size and concentration in a control room environment.
|Both systems consists of a laser optical flow through cell. The user must provide power and clean filtered water. The instruments monitors the sediment properties on a user selected schedule. When the concentration exceeds a factory pre-set threshold, the LISST-Infinite will perform a dilution step before making a measurement of the concentration and size distribution. Typically, below about 2,000 mg/l (precise number depends on sediment size) no dilution is required. Thus, the upper range of concentration that the LISST-HYDRO can work in is around 2,000 mg/l. For the LISST-Infinite, the upper concentration limit is around 30,000 mg/l. See the article 'LISST Concentration Limits' for more information on what influences these limits.|
|Some capabilities are shared between the LISST-Infinite and the LISST-HYDRO. The list below details these shared capabilities.|
- Measurement of size distribution and concentration; the size distribution reports concentration in 32 log-spaced size classes covering the size range from 2.5 to 500 microns
- Control Room strip chart display of history and current data on a dedicated computer;
- Systems can be programmed to set off alarms at user-selected thresholds in user-selected size classes
- Data can be archived, archived and hard-wired, or archived and telemetered to a remote site via RF or satellite links.
|Additionally, the LISST-Infinite has the following capabilities unique to the LISST-Infinite: |
- Auto-dilution system for continued operation in high-concentration environments (concentration in excess of 2,000 mg/l).
- The auto-dilution system consists of a dilution chamber, a mixer pump and a pinch valve system. The pinch valves enable the LISST-Infinite to capture a small sample of turbid water, transfer it to the dilution chamber where it is diluted 10:1, and then recirculated using the mixer pump through the optics system for a second measurement.
- With the dilution, the upper concentration range is extended to about 30,000 mg/l (ppm by mass).
|Sequoia is pleased to offer a complete turn-key solution from installation to data display and alarm settings (but not including civil works). For more information about capabilities, as well as installation requirements and shared responsibilities between customer and Sequoia, please click here. |
|For price quotes, please contact us.|
| Updated 6/15/2011|
|LISST-SOP 5.0 Released |
|LISST-SOP 5.0 for LISST-100X and LISST-Deep released! |
-Inversion of randomly shaped particles
-Command line batch processing
-Improved serial port communication
|HydroVision International 2013 |
Denver, CO, 23-26 July 2013, booth 337
Seattle, WA, 12-15 August, booth 224
Oceanology International CHINA
Shanghai, China, 3-5 September 2013
35th IAHR World Congress
Chengdu, China, 8-13 September 2013, booth 308
AEG 56th Annual Meeting
Seattle, WA, 9-13 September, booth 31
SPE ATCE 2013
New Orleans, LA, 30 September-2 October 2013, booth 2503
AGU Fall Meeting
San Francisco, CA, 9-13 December 2013, booth 739