FGD Recycle Pumps – True Cost Investigation

The only exhibitor of FGD recycle pumps at Power-Gen is Duechting.

80,000 MW of limestone FGD recycle pumps will be purchased in India over the next three years. Over 1.5 million MW of these large pumps are continually being operated at power plants around the world. Their  true cost (total cost of ownership) is a substantial percentage of the true cost for electricity production. One reason is the choice of pump energy over fan energy.

 It can be argued that scrubbers using less recycling slurry but more fan energy are a better choice but the coal fired power industry has standardized on the spray tower type of limestone scrubber.  For a 1000 MW scrubber the recycled slurry will be as much as 200,000 gpm delivered to the top of a spray tower at a 50-100 ft elevation. This slurry is an abrasive, corrosive combination of gypsum, calcium sulfite and limestone particles along with some residual flyash. The pumps are expected to remain functional for 20 years or more.

The true cost of the pump purchase is impacted by many factors

·         System design: the piping design, pump location, valve resistance, spray tower nozzle type, chloride bleed provisions, requirement for spares and other factors

·         Pump design including initial efficiency, deterioration characteristics, and pump characteristics

·         Energy consumption for the new pump and during the cycle prior to repair

·         Cost of energy

·         Cost of repair parts and frequency of replacement

·         Cost for service

·         Operational factors such as maintenance quality, hours of operation per year etc.

·         Downtime costs

·         Labor rates

·         Related costs such as greater use of limestone or treatment chemicals with varying pump performance

India has adopted specifications with minor modifications which were first written decades ago for projects in the U.S. or Japan. A recent BHEL specification for an FGD system in Bangladesh Is for two generators each 660 MW and each unit with one FGD system. Each FGD system will be provided with five recirculation pump (4 working + 1 standby) which are located inside the Recirculation Pump & Oxidation Blower House.

The specifications for the recirculating pump allow for rubber lining, stainless alloys or silicon carbide materials in contact with the sulfite slurry with a maximum of 27,000 ppm chlorides.

http://www.bhel.com/dynamic_files/tender_files/pdf/BIFPCL%20MAI%20%20FGD%20ARP%20R01.pdf

This worldwide standardization of scrubber designs and pump requirements means that there is ample evidence of true cost of the various pumps which have been utilized and the ability to project true costs for future installations.

True cost is impacted by the location where the pump is manufactured and the location where the pump is repaired. It is also impacted by the service personnel proximity and the option for remote monitoring and support.

Libra Fluid Equipment Co., Ltd is home based in China. It was founded in 1999 and provides pumps and parts for various industries. It supplies pump parts for any pump where the patents have expired.  It supplies ceramic, alloy and rubber lined impellers. This has true cost implications. The true cost of a pump purchased from any company without recently patented parts may be reduced with the option of purchasing parts from others such as Libra.

Parts and repair is a major true cost factor. Duechting Pump manufactures pumps in Germany but has regional service centers around the world. Is the true cost greater or the same for pumps supplied in the U.S and Asia? 

KSB is a German based company but purchased GIW and manufactures pumps in the U.S.  

Trillium has multiple manufacturing and service locations.

Continuing evidence based on experience: As suppliers gain additional evidence it can be incorporated. The process is likened to a criminal trial where the supplier is the prosecutor and the jury is the purchaser. The difference is that the jury is periodically asked to review its decision based on new evidence such as life of impellers and casings in this recent case history.

The scrubber recycle pumps in the plant described in the link have operated at a flow rate of 1,310 cubic meters per hour (m3/h), 21.1 meters (m) of head and 630 revolutions per minute (rpm) for nearly 20 years, requiring minimum attention and service. Of course, the mechanical seals were exchanged from time to time. Apart from that, four impellers, one casing cover and some minor components were replaced. An additional 24 pumps are installed in the second scrubber system and other applications in the plant.

https://www.pumpsandsystems.com/pump-materials-wet-flue-gas-desulfurization

There should be separate true cost analyses for each location.  It is particularly important to analyze the cost in India.  A good example is the analysis by SHI FW relative to wet vs dry scrubbers for Indian power plants.

Sumitomo SHI FW has made a detailed analysis comparing CFB scrubbers to wet limestone scrubbers without wallboard quality gypsum production. 

The  lower quality of limestone available, the expected 15-year life for the older plants to which the system may be applied, and the much lower capital cost of the CFB design are key aspects in the determination. Here are the factors and calculations for a 300 MWe  pulverized boiler contained in the linked paper.

 http://home.mcilvainecompany.com/images/Article_Show_me_the_Money_CFBS_vs_Wet_FGD_Aug19.pdf

Libra provides Ceramic Pumps and Impellers

Libra Fluid Equipment Co., Ltd. was founded in 1999 and provides pumps and parts  for various industries, such as mining, metallurgy, coal, power, petroleum, chemical, municipal, environmental, etc.

As a China-based slurry pump impeller manufacturer, Libra provides a broad range of impellers, including froth pump impeller, medium/light duty pump impeller, sump pump impeller, sand pump impeller and FGD (flue gas desulfurization) pump impeller or customized impellers.

It produces its own pump impellers, and also can provide impellers for competitor pumps Libra Fluid does not represent or is not in any way affiliated with original pump manufacturers. As for the slurry pumps, Libra endeavors to “only supply parts to the aftermarket where components were originally designed and developed over twenty years ago (which other OEM’s have well and truly enjoyed returns to justify the initial product development – the reason patents expire after 20 years!).

The  aim is to provide end users an alternative supplier and so bring competition back into the pump aftermarket resulting in end users paying fair prices, obtaining realistic lead times, having better product support, and encouraging future product improvements by all OEM’s. All companies and end users benefit from competition.”

Duechting  Ceramic Pumps demonstrate Lowest Cost of Ownership in U.S. Cement Plant

Due to its significant corrosive and abrasive characteristics, gypsum slurry is a very difficult medium to handle. An American cement plant with a yearly capacity of about 2 million metric tons has found a good solution for that issue when it installed the first of two scrubber systems in 1998. This application has similar wear characteristics to FGD.

The housings of the eight pumps in the limestone slurry cycle are not made from metal materials, but from a special material that was designed specifically for extremely harsh conditions. This material is a mixture of silicon carbide (SiC) and epoxy resin that is poured into precision molds and heat cured to form the pump components. The material must be machined with diamond tools due to it exhibiting a hardness close to that of diamonds. The material is completely impervious to corrosion and exhibits extreme abrasion resistance given its metallic-free composition and high hardness value.

The scrubber recycle pumps in this plant have operated at a flow rate of 1,310 cubic meters per hour (m3/h), 21.1 meters (m) of head and 630 revolutions per minute (rpm) for nearly 20 years, requiring minimum attention and service. Of course, the mechanical seals were exchanged from time to time. Apart from that, four impellers, one casing cover and some minor components were replaced. An additional 24 pumps are installed in the second scrubber system and other applications in the plant.

https://www.pumpsandsystems.com/pump-materials-wet-flue-gas-desulfurization

Sunbo supplies FGD Pumps and Parts from Chinese Factory

Sunbo Pump supplies slurry pumps and replacement parts for Warman pumps. It supplies replacement slurry pump parts in High chrome alloy, Rubber (Elastomer) and Polyurethane, e.g. R55,S42 (Neoprene), U01 (Polyurethane), S12 (Butadiene), S21 (Butyl), SO₂ (EPDM), SO₂ (Haipalun gum), and special materials. Sunbo is headquartered in Shijiazhuang, China. It develops, manufactures and globally markets slurry pumps for delivering aggressive, abrasive, thick, or solid-filled slurries. 

Hanhe is a Chinese FGD Pump and Parts Supplier with exports to India

Hanhe Pump Co., Limited is a  slurry and dredging pump manufacturer and exporter. With more than 15-year development it has slurry pump design, production, on-site installation, technical support and approved by ISO9001:2008 certificate. It supplies slurry pump for Weir Pumps but is not associated with Trillium. It is located in Shijiazhuang City, China. It has offices in India at Hanhe Slurry Pumps Solutions D, Maharashtra, India.

Background Data in FGD Knowledge Network (free access for power plants)

There are 384 articles about pumps in the FGD & DeNOx newsletter

1. Pump Hot Topics were Availability and Pump Materials

... FGD and DeNOx NEWSLETTER June 2007 No. 350 Pump Hot Topics were Availability and Pump Materials On April 5 pump experts provided alternative views on pump materials but did ...

2. Düchting SICcast® FGD Pump is Abrasion Resistant

... FGD and DeNOx NEWSLETTER January 2007 No. 345 Düchting SICcast® FGD Pump is Abrasion Resistant The unique, patented and proven SICcast® FGD slurry pump technology developed ...

.com/fgddenox/subscriber/fgdnl240/FGD%20Pumps.htm

4. Consider Shaft Sealing, Cable Entry, Cooling When Choosing Pumps for FGD Slurries

... FGD and DeNOx NEWSLETTER June 2007 No. 350 Pump Hot Topics were Availability and Pump Materials On April 5 pump experts provided alternative views on pump materials but did ...

16. HH 07 01 11 “Selecting the Right Pumps and Valves for Flue Gas Desulfurization”

... HH 07 01 11 "Selecting the Right Pumps and Valves for Flue Gas Desulfurization" by Dan Ellis, ITT Engineered Valves, Lancaster, PA and Haminder Ahluwalia 

Articles in Coal Fired Power Plant Decisions - Intelligence System  (free to power plant owners)

 Duechting ceramic pumps demonstrate low cost of ownership in U.S. cement plant

Due to its significant corrosive and abrasive characteristics, gypsum slurry is a very difficult medium to handle. An American cement plant with a yearly capacity of about 2 million metric tons has found a good solution for that issue  Revision Date:  10/23/2019

BHEL specifications for FGD pumps in Bangladesh project

There are 2 units of each 660 MW and each unit is envisaged with one FGD system. Each FGD system will be provided with 5 numbers of Recirculation pump (4 working + 1 standby) which are located inside the Recirculation Pump & Oxidation Blower House. The specificiations for the FGD recirculating pump allow for rubber lining, stainless alloys or silicon carbide materials in contact with the sulfite slurry with a maximum of 27,000 ppm chlorides. Revision Date:  10/23/2019

Putzmeister efficiently moving dense coal ash sludge at largest brown coal plant in Europe

Putzmeister provides eco-friendly solutions to waste management and on shore drilling that follow a sustainable and efficient process. Revision Date:  6/27/2019

John Crane seal maintenance program improves pump cost of ownership in German lignite fired Power Plant

A German power plant experienced premature wear and excessive seal corrosion in its boiler feed circuit and flue gas desulfurization slurry pumps. Revision Date:  6/12/2019