Showing posts with label Roth. Show all posts
Showing posts with label Roth. Show all posts

Thursday, October 6, 2016

Regenerative Turbine Pumps

regenerative turbine pump for industrial use
Regenerative Turbine Pump
Roth Pump
Most of us are familiar with centrifugal pumps and their generally understandable operating design. A regenerative turbine pump is significantly different in the way in which liquid moves through the impeller section, enabling this pump type to prove advantageous in a number of industrial applications.

A centrifugal impeller basically traps some liquid at the inlet and rapidly slings through the discharge port. The liquid velocity is increased by the impeller and manifests as outlet pressure. The key distinction here is that the liquid enters and exits the impeller only one time. A regenerative turbine pump has an impeller with a comparatively larger number of vanes, also of a different shape. This shape imparts a circulatory movement of the liquid from the vanes to the casing, and back to the vanes. Each return to the vane section increases fluid velocity, which can be converted to increased pressure. As the impeller rotates, liquid enters, leaves, then re-enters the vane section many times. This process is called regeneration. The impact of this design is a pump that can deliver substantially greater pressure than a centrifugal pump with the same impeller diameter and rotational speed.

A regenerative turbine pump is capable of pumping fluids with up to forty percent entrained gases without damage from cavitation or any performance loss. Fluid conditions with even low levels of entrained gases would likely produce substantial loss of performance in a centrifugal pump, evidenced as fluctuating discharge pressure and excessive wear and vibration. Where cavitation is a concern, the regenerative turbine pump holds the advantage over centrifugal. Applications with low flow and high head requirements will also be better serviced by a regenerative turbine pump.

There is more to be learned. Some additional detail and explanation are provided in the document included below. Effective solutions are developed through a combining of your process knowledge and the application expertise of a product specialist. Reach out and share your fluid transfer challenges for the best solution.

Wednesday, August 26, 2015

Steam Condensate Return Systems - Basic and Essential

Condensate Return Pump
Condensate Return Station
Courtesy Roth Pump Company
Many industrial processes and plants utilize steam in their operations. The generation and use of steam is one of the oldest industrial processes and is so well understood that it may be considered more of a utility than part an industrial process. Whatever the case, if your process or installation uses steam, then steam is a necessary input for successful operation. Keeping your steam system performing at capacity frees up time and resources for the more complex aspects of your work.

If steam is not consumed directly by the process as a component input, it is steam's heat of vaporization that is utilized by the operation. Efficient use of steam as a heating medium results in the conversion of vapor to liquid (water). Returning the liquid condensate back to the boiler for conversion to vapor again is a necessary step in the efficient operation of a closed loop system.

Condensate return systems are certainly not high technology, but keep in mind that a steam system may be the lifeblood of not just one, but many operations throughout a plant. Avoiding downtime in the steam system, of which the condensate return pump is an integral part, ranks highly on the list of "Important Things for Plant Operations". Condensate return is critical. What are some strong attributes of a good and reliable condensate return pump?


Condensate return station with dual pumps
Condensate Return Station with Dual Pumps
Courtesy Roth Pump Company
  • Minimize or eliminate cavitation at high temperatures. Cavitation will impede pump performance and cause premature deterioration of pump and drive components.
  • Ability to handle a high load during cold starts through motor and pump design.
  • Design and configuration to handle high temperatures without deterioration of pump and motor.
  • Develop higher pressure at lower motor speeds for extended service life.
  • Avoidance of mechanical seals below water line.
  • Consider a single unit with dual pumps for handling high loads and extending service life.
Specifying and installing a solidly designed and built condensate return pump may require an investment of your time and consideration. The return on that investment will be reduced maintenance, repair, and downtime. Talk to a product specialist about your steam system. Combining your intimate operational knowledge and experience with their deep product knowledge and experience with many installations will yield a good solution.



Monday, April 27, 2015

Differences Between a Regenerative Turbine Pump and a Centrifugal Pump

Regenerative turbine pump have double row vanes cut in the rim. The impeller rotates within two liners into which annular channels have been milled. Liquid flows in at the suction and is picked up by the impeller vanes. In completing nearly one revolution in the annular channel, the fluid develops a high velocity and pressure increases dramatically before being sent out the discharge. The liquid re-circulates between the impeller vanes and the annular chamber. Because of this action, the fluid flows in a path like a helical spring laid into each of the annular grooves as the fluid is carried forward. Energy is added to the fluid by a number of vortex impulses in the impeller vanes, as it travels from suction to discharge.

These impulses have the same effect as multi- staging in a centrifugal pump. In a multistage centrifugal pump, the pressure is the result of energy added in each stage. In a turbine pump, pressure is added to the fluid stream by circulating many times through the vanes of a single impeller.



One of the most remarkable features of the regenerative turbine pump is its performance characteristics when pumping highly volatile liquids. The manner in which the turbine impeller imparts velocity/energy to the fluid, as described above, is quite different from conventional centrifugal or positive displacement designs. The continuous, progressive building of pressure in a regenerative turbine pump essentially eliminates the sudden collapse of bubbles that is destructive cavitation.

turbine pump can develop about ten times the discharge pressure of a centrifugal type having equal impeller diameter and speed. Pressure increases nearly uniformly around the impeller rim. At the impeller hub, the pressure is about one half the discharge pressure. This lower pressure, plus suction pressure, is what is seen in the stuffing box. Holes through the impeller keep the impeller centered to reduce wear, prevent unbalanced pressures on the impeller and reduce end thrust on the bearings.

REGENERATIVE PUMP DESIGN ADVANTAGES
  • Develop higher pressures
  • Can be run at lower motor speeds
  • Eliminate cavitation
  • Operate with lower NPSHr
  • Deliver specified capacity with input pressure variations
  • Meet performance with fewer stages
  • Smaller size
For more information on regenerative turbine pumps, contact:

Mountain States Engineering and Controls
1520 Iris Street
Lakewood, CO 80215
303.232.4100 Phone
303.232.4900 Fax
Email: info@mnteng.com