Grizzly G0601 owner manual Calculating Duct Resistance, Duct Approximate Dia, Loss Per Foot

Page 41

Calculating Duct Resistance

Adding duct work, elbows, branches and any other components to a duct line increases airflow resistance (static pressure loss). This resistance can be minimized by using rigid (smooth) pipe and gradual curves, as opposed to flexible pipe and 90˚ elbows.

To help you think about this resistance, imagine riding a bicycle in a tunnel that is an exact replica of the duct work. If the inside of the tunnel is very bumpy (flexible pipe) and has a lot of sharp turns (90˚ elbows), it will take a lot more effort to travel from one end to the other.

The purpose of calculating the resistance is to determine if it is low enough from the machine to the dust collector to meet the given CFM require- ment for the machine. Use the charts in Figure 53 to calculate the resistance of duct work.

Duct

Approximate

Approximate

Dia.

Static Pressure

Static Pressure

 

Loss Per Foot of

Loss Per Foot

 

Rigid Pipe

of Flex Pipe

 

Main

Branch

Main

Branch

 

Lines

Lines

Lines

Lines

 

at 3500

at 4000

at 3500

at 4000

 

FPM

FPM

FPM

FPM

2"

0.091

0.122

0.35

0.453

2.5"

0.08

0.107

0.306

0.397

3"

0.071

0.094

0.271

0.352

4"

0.057

0.075

0.215

0.28

5"

0.046

0.059

0.172

0.225

6"

0.037

0.047

0.136

0.18

7"

0.029

0.036

0.106

0.141

8"

0.023

0.027

0.08

0.108

9"

0.017

0.019

0.057

0.079

 

 

 

 

 

Fitting

90˚

45˚

45˚

90˚

Dia.

Elbow

Elbow

Wye(Y)

Wye(Y)

 

 

 

 

 

3"

0.47

0.235

0.282

0.188

4"

0.45

0.225

0.375

0.225

5"

0.531

0.266

0.354

0.236

 

 

 

 

 

6"

0.564

0.282

0.329

0.235

 

 

 

 

 

7"

0.468

0.234

0.324

0.216

 

 

 

 

 

8"

0.405

0.203

0.297

0.189

 

 

 

 

 

Figure 53. Static pressure loss charts.

Model G0442/G0601 (Mfg Since 8/10)

In most small/medium shops it is only necessary to calculate the line with the longest duct length or the most fittings (operating under the assumption that if the line with the highest resistance works, the others will be fine).

To calculate the static pressure of any given line in the system:

1.Make a list of each size duct in the line, includ- ing the length, and multiply those numbers by the static pressure value given in Figure 53.

2.List each type of elbow or branch and multiply the quantity (if more than one) by the static pressure loss given in Figure 53.

3.Add the additional factors from Figure 54 to the list.

Additional Factors

Static Pressure

 

 

Seasoned (well used)

1"

Dust Collection Filter

 

 

 

Entry Loss at Large

2"

Machine Hood

 

 

 

Figure 54. Additional factors affecting static

pressure.

4.Total the list as shown in the example in Figure 55 to come up with the overall static pressure loss number for that line.

Note: Always account for a seasoned filter, so you don't end up with a system that only works right when the filter is clean.

Main Line

 

 

6" Rigid Pipe (0.037) at 20'

0.740

Branch Line

 

 

4" Rigid Pipe (0.075) at 10'

0.750

4" Flex Pipe (0.28) at 5'

1.400

Elbows/Branches

 

 

6" 45˚ Y-Branch

0.329

4" 45˚ Elbow

0.225

Additional Factors

 

 

Seasoned Filter

1.000

 

 

 

Total Static Pressure Loss

4.444

Figure 55. Example list for totaling SP loss.

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Contents HP Cyclone Dust Collector Page Table of Contents Manual Accuracy IntroductionContact Info Machine DescriptionIdentification Model G0442 shown IdentificationMachine Data Sheet Bag Information Performance Curve G0601 Machine Data Sheet Air Suction Cap CFM @1.9 in. S.P G0601 Performance Curve Safety Instructions for Machinery SafetyUnattended OPERATION. Never­ leave­ Additional Safety Instructions for Dust Collectors Availability Power SupplyFull-Load Current Rating Circuit RequirementsG0601 Circuit Requirements for 440V G0601 Circuit Requirements for 220VGrounding Instructions Grounding & Plug Requirements50 ft Extension Cords 220V OnlyG0601 440V Conversion To rewire the Model G0601 for 440V opera- tionCorrecting Phase Polarity G0601 Only Needed for Setup SetupUnpacking Description QtyInventory Collector Box Contents Figure QtyContents of Filter Boxes Figure Qty Stand Box Contents Figure QtyHardware Recognition Chart Site Considerations Bolting to Concrete Floors Using Machine MountsMounting to Shop Floor Assembly Foam tape attached to the intake Cylinder Aligning the mounting holes Tape Cyclone vacuum tube and hose Attachment Page Tip Use an adhesive to keep the seal in place Connecting the vacuum hose Model G0442/G0601 Mfg Since 8/10 Switch mounted to stand Model G0442/G0601 Mfg Since 8/10 To test run the dust collection system Test RunFor Model G0601 Only General System DesignDucting Materials Metal DuctPlastic Duct Flexible DuctDecide Who Will Design Designing Ducting SystemSketch The Shop Layout Sketch a Basic Duct LayoutMachine Approximate Determine CFM of Each MachineMachine Determining Main Line Duct DiameterMultiple Dust Ports Determining Branch Line Duct DiameterTwo Machines on Same Branch Line Total CFM Branch Line SizeDuct Approximate Dia Calculating Duct ResistanceLoss Per Foot Fitting 90˚ 45˚ Dia Elbow WyeY1785 Closest CFMSystem Grounding Operations Remote ControlControl Box Panel Metal Duct Starter Kit AccessoriesMetal Branches Metal ElbowsReducers & Adapters G6252-4 Floor Sweep G7341-5 Floor Sweep G7342-6 Floor SweepCleaning Filters MaintenanceSchedule Emptying DrumRemoving/Replacing Filter Rinsing FilterTools Needed Qty To replace the canister filterPage Troubleshooting ServiceRefer to Designing Ducting System, beginning Wiring Safety Instructions WiringModel G0442 G0442 Wiring DiagramModel G0601 G0601 Wiring DiagramMain PartsG0442/G0601 Common Parts List G0442 Only Parts ListG0601 Only Parts List Description Page Page Comments Warranty CardBOX BELLINGHAM, WA Grizzly INDUSTRIAL, INCWarranty and Returns Warranty and ReturnsOrder Hours a DAY
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