News from Schwing Bioset

Pima County, AZ, Tres Rios WRF Biosolids System Upgrades - Part Three: Mobile Dewatering Equipment Rentals

 

Written by Josh DiValentino

 

Background: The district of Pima County, AZ, operates a total of eight wastewater treatment plants. The Tres Rios Water Reclamation Facility (WRF) is the centralized biosolids processing facility for all Pima County plants. Tres Rios WRF currently operates 24/7/365 at a 30 MGD capacity, with a projected flow of 50 MGD in 2030. The facility process is; BNR, Anaerobic Digestion, Dewatering, Pumping, Truck Loading, and Land Application of biosolids (cotton is a common use). For nearly 20 years, Schwing Bioset, Inc. has provided solids handling solutions at Tres Rios with projects ranging from biosolids cake pumping and cake storage bins, to most recently, nutrient recovery and temporary Screw Press dewatering equipment.

 

Mobile Dewatering Units: During the Summer of 2020, Tres Rios WRF needed to take down their entire centrifuge dewatering facility for contractors to install the second new Schwing Bioset Cake Pump. The pumping system details are explained in Pima County, AZ, Tres Rios WWTP Biosolids System Upgrades - Part One: Cake Pumping. Operations had to find a reliable solution to divert flow from the entire 30 MGD facility. Schwing Bioset again had an opportunity to help, providing our massive FSP1103 and FSP703 Screw Press dewatering trailers for temporary dewatering.

 

Pima County Tres Rios Dewatering Screw Press Rental


Thickened sludge was fed from the Anerobic Digester to both presses. Once the sludge feed was connected via cam-lock hoses, power connected to the trailer, and the drain lines hooked up, the Screw Presses were ready to run. Technicians dialed in the polymer dose, screw press floc tank pressure, screw rotation speed, and discharge cone pressure to optimize performance. The Tres Rios operations team could then to divert sludge flow to the temporary dewatering trailers, and each system is capable of the following throughput:  

 

FSP1103 Trailer: Anaerobic Sludge

3208 dry lbs. / hour (1455 dry kg / hour) up to 214 gallons /minute (810 liters / minute) at 3% solids


FSP703 Trailer: Anaerobic Sludge

1365 dry lbs. / hour (620 dry kg / hour) up to 90 gallons /minute (340 liters / minute) at 3% solids

 

The FSP Screw Presses provided reliable dewatering for the entire Tres Rios facility for a few weeks while the new cake pump was installed. The presses were able to produce cake and filtrate quality performance near the plants existing centrifuges, producing an average of 17% cake solids while running near design capacity. The FSP screw press dewatering systems offered this level of high-performance dewatering and are a simple, easy to maintain, low energy consuming package, even at high flow rates from big plants.

 

Pima County Tres Rios Dewatering Screw Press Rental  

Click here to read more about our Products, then contact us to learn more about this project or find out how we can help your plant too.

 

Read the previous Pima County Project stories and stay tuned for Part Four on Struvite Management:

Part One: Cake Pumping

Part Two: Live Bottom Bins

Part Four: NuReSys Struvite Management Project

 

 Download Our Brochures    or Application Reports

Read More Schwing Bioset  News and Blog Articles

 

Tags: Biosolids, Dewatering, Mobile Screw Press, Water Reclamation Facility

Pima County, AZ, Tres Rios WRF Biosolids System Upgrades - Part Two: Live Bottom Cake Bins

 

Written by Josh DiValentino

 

Background: The district of Pima County, AZ, operates a total of eight wastewater treatment plants. The Tres Rios Water Reclamation Facility (WRF) is the centralized biosolids processing facility for all Pima County plants. Tres Rios WRF currently operates 24/7/365 at a 30 MGD capacity, with a projected flow of 50 MGD in 2030. The facility process is; BNR, Anaerobic Digestion, Dewatering, Pumping, Truck Loading, and Land Application of biosolids (cotton is common use). For nearly 20 years, Schwing Bioset, Inc. has provided solids handling solutions at Tres Rios with projects ranging from biosolids cake pumping and cake storage bins, to most recently, nutrient recovery and temporary Screw Press dewatering equipment.

 

Live Bottom Cake Storage: In 2012, the facility completed a Regional Optimization Master Plan expansion, which included upgrades to the centrifuge building and a new truck loading building. Prior to this expansion, dewatered cake was pumped (using the original Schwing Bioset Piston Pump) directly through a pipeline to the truck loading area. There was no intermediate storage capacity in the system on the dewatered cake side. Further, trucks could only be filled as fast as the cake pump could deliver cake, significantly reducing truck fill times.

 

Tres Rios Storage w-caption 2During the 2012 expansion, Schwing Bioset, Inc., supplied the new truck loading cake bins. Three (3) live bottom bins were provided, each with a capacity of 3,000 cubic feet of cake storage.

  • Bin Silo Sizing Details (each): Circular Design, 12’ diameter and 33’ tall storage area. Total height of 51’ including truck loading area.

Each bin utilizes a live bottom to deliver biosolids cake to the trucks below. The live bottoms are center discharging.

  • Bin Live Bottom Details (each): 18” diameter shafted, Twin Screws. Complete with 36” x 36” pneumatically actuated slide gates to control cake fill.

 

The top of the bins extend through the roof of the truck loading building. The bins provide storage capacity for dewatered cake and can fill trucks in less than 15 minutes when needed. The systems came complete with access ladders, safety railing, and ventilation connections for odor control. The bins have been in operation for nearly a decade, requiring only regular upkeep and maintenance to bearings and drive systems.

 

Click here to read more about our Products, then contact us to learn more about this project or find out how we can help your plant too.

 

Read Part One: Cake Pumping

Stay Tuned for More on Pima County Projects:

Part Three: Temporary Screw Press Dewatering

Part Four: NuReSys Struvite Management Project

 

 Download Our Brochures    or Application Reports

Read More Schwing Bioset  News and Blog Articles

 

Tags: Biosolids, Wastewater Treatment, Water Reclamation Facility, Live Bottom Bins

Pima County, AZ, Tres Rios WRF Biosolids System Upgrades - Part One: Cake Pumping

 

Written by Josh DiValentino

 

Tres Rios Storage w-caption 2Background: The district of Pima County, AZ, operates a total of eight wastewater treatment plants. The Tres Rios Water Reclamation Facility (WRF) is the centralized biosolids processing facility for all Pima County plants. Tres Rios WRF currently operates 24/7/365 at a 30 MGD capacity, with a projected flow of 50 MGD in 2030. The facility process is; BNR, Anaerobic Digestion, Dewatering, Pumping, Truck Loading, and Land Application of biosolids (cotton is common use). For nearly 20 years, Schwing Bioset, Inc. has provided solids handling solutions at Tres Rios with projects ranging from biosolids cake pumping and cake storage bins, to most recently, nutrient recovery and temporary Screw Press dewatering equipment.

 

Cake Pumping:  Since the early 2000’s to 2012, the Tres Rios WRF had used a piston pump for biosolids cake conveyance to truck loading. In 2012, the facility completed a Regional Optimization Master Plan expansion, which included an upgrade to the centrifuge building and loading building. The upgrade design replaced the existing piston pump with progressive cavity pumps dedicated to each of the three new centrifuges.

After 6 years of struggling with excessive downtime associated with the progressive cavity pumps, the 10+ year-old piston pump was pulled from storage, sent to Schwing Bioset, Inc. to be rebuilt and reconfigured to fit the existing building, and installed to replace one of the progressive cavity pumps.

Since its reinstallation, the plant has used the piston pump as its primary pump, reducing the downtime and maintenance costs associated with the progressive cavity pumps. The facility no longer needs to de-rate the centrifuges and has been able to dewater the biosolids to a higher percent solids content when using the piston pump, significantly reducing hauling costs. The subsequent uptime and increase in dry cake solids production justified the capital cost of buying an additional Piston Pump, as the payback was determined to be 2 years. One progressive cavity pump will remain in service as an emergency backup for pumping thickened sludge, which is usually thickened from 6% to 8% solids.

The second new Piston Pump will come online in 2020. The Schwing Bioset, Inc. Engineering Team also worked with the district to perform a complete pipeline analysis of the existing cake pipeline. This identified the pipeline upgrades required to re-certify the pipeline for higher pumping pressures, resulting from higher cake solids and higher flow via the Piston Pumps to Truck Loading. This pump technology conversion clearly illustrates that while the initial capital expense of a piston pump is higher than a progressive cavity pump, the long-term expenses over the operating life of the equipment, when factoring in hauling expenses, maintenance costs, and operational downtime, heavily favor piston pump technology.

 

Schwing Bioset Piston Pump

 

For more information on this project, read the paper below or contact us.  

 

Additional Info: Biosolids Cake Pumping Life Cycle Analysis - A True Operators Story

Stay Tuned for More on Pima County Projects:

Part Two: Live Bottom Bins

Part Three: Temporary Screw Press Dewatering

Part Four: NuReSys Struvite Management Project

 

 Download Our Brochures    or Application Reports

Read More Schwing Bioset  News and Blog Articles

 

 

Tags: Piston Pumps, Biosolids, Biosolids Piston Pump, Water Reclamation Facility