Pump Styles. Understanding the Differences Between. Dewatering Pumps, Sewage Pumps, and Grinder Pumps.

Transcription

1 Pump Styles Understanding the Differences Between Dewatering Pumps, Sewage Pumps, and Grinder Pumps. Presented by: Darren Meyers, P.E. Zoeller Pump Company

2 Why Do We Pump? Pumping gives us options We re not constrained by gravity. We can avoid greater costs. Larger construction costs Larger pump costs We gain control!

3 Wastewater Defined Sewage Raw Wastewater (including solids) from toilettes & drains Effluent Wastewater (mostly liquid) which has passed through a septic tank Groundwater (o.k.- so it s not wastewater) Mostly clean, but may contain some silt

4 Three Keys to Trouble-Free Pump Operation 1. Proper Selection Picking the right pump for the job 2. Correct Installation Clean, safe, organized 3. Periodic Maintenance Keeping a pump in top shape

5 One Size Does NOT Fit All! Pumps have been designed according to specific needs. Each style has a particular application. Choosing the correct pump style is as critical as choosing the correct pump size.

6 Most Common Pumps for Wastewater Installers Sump / Effluent / Dewatering Little or no solids Sewage Ejectors Varying solids passing capabilities Grinders Solids environment

7 Dewatering / Effluent Pumps Dewatering pumps are designed to move liquid which is mostly solids free Groundwater Sump applications Effluent Onsite dosing applications

8 Dewatering Pump Characteristics Little to no solids handling capability Sometimes none Sometimes up to ¾ Typically smaller pipes (1 to 2 ) Higher head pressures Lower flow rates

9 Sump Pumps Intended for use in groundwater removal applications. Often contain an integral side switch. May be partially above and below the waterline

10 Effluent Pumps Intended to pump septic tank effluent. Does not have any integral switch Must be kept below the waterline Corrosive gasses build up in a septic environment

11 Effluent Turbine Pumps Turbine pumps are designed and built very differently than centrifugals. These pumps have no solids handling capabilities. Units consist of a motor end and an impeller end. Replacement ends, motor or impeller, are typically available and simple to change out.

12 Sewage Pumps a.k.a. Sewage Ejector, Non-Clog Sewage pumps are designed to pump whole solids from a basin to some other location Gravity sewer Septic tank

13 Sewage Pump Characteristics Designed to handle solids 2 solids or greater Larger pipes (greater than 2 ) Lower head pressures Higher flow rates

14 Grinder Pumps Grinder pumps chop and grind raw sewage into little bits to more easily move it through a piping network. Grinder pumps come in two styles: Centrifugal Progressing Cavity

15 Centrifugal Grinders Curves are similar to large effluent pumps Use standard impellers to move the sewage slurry after chopping it. Used most frequently in: Sites just downhill from a gravity sewer Problematic sites where sewage pumps may clog Prisons, nursing homes, schools, etc.

16 Progressing Cavity Grinders Produce very high heads and relatively small flows. Use a corkscrew type action to lift ground-up sewage Use most frequently in: Applications requiring very high pressures Pressure sewer networks High heads/low flows are ideal for networks with large numbers of units.

17 Pumping into a Septic Tank Sewage pumps are appropriate Transfer whole solids Do not use grinders to pump into septic tanks. Solids are ground too finely to settle out.

18 Pump Sizing in Two Slides! Static Head Actual elevation change Friction Head Loss due to frictional resistance between water and pipe Operating Head Pressure required in some systems (LPP, Pressure Dist., etc.) Static Head + Friction Head + Operating Head = Total Dynamic Head (TDH)

19 Size Based On Pump Curve Pump Curves are easily accessible for any pump on the market. Find where the calculated TDH and the desired flow intersect on the graph. Select a curve which crosses close to but above this point. Always try to stay toward the middle of the curve, as this is where the pump is most efficient.

20 Thank You for Your Attention