MK Plastics DHK-NW IO&M User Manual

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Page 1

Bulletin 40-02-June 2013

REVISIONS

REV.

DESCRIPTION

Revision DATE

APPROVED

ZONE

E.C.O. No:

REVISED

ALL

EMISSION

N.A.

04/27/09

LIU

CORPORATION

SERVING THE NEEDS OF MODERN INDUSTRY

INSTALLATION, OPERATION AND MAINTENANCE MANUAL

Introduction

This bulletin contains the proper installation, operation and maintenance procedures for the standard DHK & DHK-NW Medium to High Pressure Centrifugal Fiberglass Fan, to ensure safe and trouble-free fan operation.

The M.K. Plastics catalog on the above corrosion resistant FRP fan, provides additional information describing the equipment, fan performance, available accessories, and

specications.

For additional safety information, refer to AMCA publication 410-96, Safety Practices for Users and Installers of Industrial and Commercial Fans.

For Information on special fan application requirements,

contact M.K. Plastics corporate ofce at (514) 871-9999.

DHK & DHK-NW

Centrifugal Fiberglass Fan

Handling

Fans are to be hoisted and moved by the lifting lugs provided

on the fan (see Figure 1). Location of lugs & brackets varies

by fan size and arrangement. Fans can also be hoisted with slings placed around the fan housing. When a single hoist is used, a “spreader” will keep the sling from slipping on the

housing. Large units may have lifting lugs or holes which

should be used only to stabilize the unit while using a sling to support the weight.

Chain or wire slings should be well-padded where they contact the fan as not to cause damage to the berglass surface. Fans should never be lifted by the shaft, fan housing, motor, belt guard, damper, weather hood, inlet &

outlet anges or any other accessories.

Lifting Lugs

Receiving and Inspection

All M.K. Plastics fans are carefully inspected before leaving the factory. Compare all components with the bill of lading or packing list to verify that the proper unit was received. Check each unit for any damage that may have occurred in transit. Mishandled units can void the warranty provisions. If units are damaged in transit, it is the responsibility of the receiver to make all claims against the carrier. M.K. Plastics is not responsible for damages incurred during shipment.

WARNING This unit has rotating parts. Safety precautions should be exercised at all times during installation, operation, and maintenance. ALWAYS disconnect power prior to working on fan.

Lifting Lugs

Figure 1.

Lifting Using the Lifting Lugs

Storage

If the unit cannot be installed and operated immediately, precautions need to be taken to prevent deterioration of the unit during storage. The user assumes responsibility of the fan and accessories while in storage. M.K. Plastics will not be responsible for damage during storage.

Store in a dry, protected area being sure fan shaft, bearings and impeller are protected against dust and corrosion. If it is necessary to store outdoors or within a building under construction, special care must be taken to prevent moisture, dirt or dust accumulation. Coat the shaft with grease or rust preventative compound. Cover and seal bearings to prevent entrance of contaminants. Impeller should be rotated at least once a month to circulate the grease in bearings. If stored outdoors, cover completely with a tarp or heavy plastic wrap. Electrical connections and leads must be protected from moisture. Block impeller to prevent natural rotation. Do not allow material of any kind to be piled on top or inside of fan.

M.K. Plastics Corp. Montréal, Québec www.mkplastics.com Page. 1

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Pre-Installation

When the unit is removed from storage after a long duration, all bearing grease should be purged and replenished with fresh grease as per the lubrication decal. The motor should be measured to verify that the resistance is still at a satisfactory level compared to the value recorded prior to storage.

Inlet & Outlet Fan Installation

Efcient fan performance relies on the proper installation

of inlet and discharge ducts. Installations with poor inlet or

discharge congurations may result in reduced performance. Restricted or unstable ow at the fan inlet can cause pre

rotation of incoming air or uneven loading of the fan wheel resulting in increased system losses and sound levels.

Free discharge or turbulent ow in the discharge ductwork

will also result in system losses. Make sure the following recommendations are followed.

Inlet Duct Turns

Installation of a duct turn or elbow too close to the fan inlet reduces fan performance. To achieve full fan performance, there should be at least three effective wheel diameters between duct turns or elbows and the fan inlet.

Poor

Discharge Duct Turns

Where possible, allow minimum three duct diameters between turns or elbows and fan outlet. Fan performance is reduced when turns are made immediately off the fan discharge.

Poor

Good

Min.

3 x Dia.

Turning Vanes

Figure 2 - Inlet Ducting

Good

Inlet Spin

A common cause of reduced fan performance is inlet spin. To prevent this occurring, it is good practice to use turning vanes in the duct to reduce the effects.

Good Poor

Figure 3 - Inlet Spin

Figure 4 - Outlet Ducting

Free Discharge

Avoid a free discharge into the plenum. This will result in

lost efciency because it doesn’t allow for a static regain.

Figure 5 - Free Discharge

Fan Installation

Follow proper handling instructions given earlier.

• Move the fan to the nal mounting position.

• Remove skid, crates, and packing materials carefully.

• If supplied, place vibration pads or isolation base on

mounting bolts. Line up holes in fan base with bolts.

• Place fan on mounting structure. Carefully level utilizing

shims as required at all mounting hole locations. Bolt down the unit.

• Any grout may now be used. Bolt the fan in position

before applying grout. Do not depend upon grout to support rotating equipment.

• Continue with Operations Checklist.

Additional instructions may be given for some fan sizes, components and accessories in the submittal.

M.K. Plastics Corp. Montréal, Québec www.mkplastics.com Page. 2

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Isolation and Support Foundation

Essential to every DHK fan installation is a strong, level foundation. A correctly designed concrete foundation with a structural steel base or inertia base provides the best

means of supporting oor mounted units. Any foundation

size is determined by the fan arrangement, size, weight, motor weight, position or fan orientation and location of the installation. The weight of the foundation must be greater

than the weight of the fan and its motor. Roof or oor structure

supports should be per the structural engineer, in accordance with load requirements and applicable building codes.

Isolation Base

Figure 5 - Isolation (Unitary) Base

Vibration Isolators

To prevent vibration and noise from being transferred to the building, vibration isolators are recommended. Isolators should be located between the fan system and the support structure. M.K. Plastics supplies three main types of isolators for FRP fans:

• Floor Mounted Seismically Restrained Spring Isolators

(1” to 4” deection)

• Floor Mounted Non-Restrained Housed Spring Isolators

(1” to 3” deection)

• Floor Mounted Rubber-In-Shear Isolators (rubber

mounts)

Refer to the M.K. Plastics submittal for isolator installation and adjustment instructions. In applications where seismic installation is required, refer to the M.K. Plastics submittal for further details.

Seismically Restrained

Spring Isolator

Housed Spring Isolator Rubber-In-Shear

Isolator

Figure 6

Vibration Isolators (Typical)

Wheel-Inlet Overlap

Efcient performance is achieved by having the correct wheel

to inlet overlap and uniform radial gap. This should always be

veried before initial start-up and if possible after the fan has

been in operation for 24 hours.

The overlap is adjusted by loosening the wheel hub on the shaft and moving the wheel to the correct position - refer to

Table 1. for values. A uniform radial gap (between the edge of wheel inlet and edge of inlet cone) is achieved by loosening

the bolts on the inlet cone and centering it on the wheel. In both cases, a trim balance maybe required.

Size Overlap

1225 7/16”

Overlap

Figure 7

Wheel/Inlet Overlap

1500 5/8”

1825 3/4”

2225 15/16”

2450 1”

2700 1-1/16”

3000 1-5/16”

3300 1-3/8”

3650 1-1/2”

4025 1-5/8”

4450 1-13/16”

4900 2”

5425 2-1/8”

6000 2-3/8”

Table 1

Wheel/Inlet Overlap

Drive Maintenance and Installation

V-belt drives need periodic inspection, retensioning, and occasional belt replacement. When inspecting drives, look for dirt buildup, burrs or obstructions that can cause premature

belt or drive replacement. If burrs are found, use ne emery

cloth or a stone to remove them. Be careful that dust does not enter the bearings. Check sheaves for wear. Excessive slippage of belts on sheaves can cause wear and vibration. Replace worn sheaves with new ones. Carefully align sheaves to avoid premature sheave failure.

Belt tension is determined by the sound the belts make

when the fan is rst started. Belts will produce a loud squeal

which dissipates after the fan is operating at full capacity. If

the belt tension is too tight or too loose, lost efciency and

possible damage can occur. The proper tension for operating a V-belt is the lowest tension at which the belts will not slip at peak load conditions. For initial tensioning, the proper belt

deection half-way between pulley centers is 1/60” for each

inch of belt span.

Deflection [inch]

After the fan, isolation base, and isolators are installed, the entire assembly must be leveled. Position the level on the isolation base, not the fan shaft, for proper leveling. Additionally, the motor and fan shafts must be level and parallel relative to each other for proper alignment.

M.K. Plastics Corp. Montréal, Québec www.mkplastics.com Page. 3

Belt Span [inch]

Figure 8 - Belt Tension

Page 4

Refer to the following procedure for belt tensioning -

1. Loosen motor plate adjustment bolts and move motor plate in order that the belts can easily slip into the grooves on the pulleys. Never pry, roll, or force the belts over the rim of the pulley.

2. Adjust the motor plate until proper tension is reached.

For proper tension, a deection of approximately 1/60” per inch of center distance should be obtained by rmly pressing the belt. Refer to Figure 8.

3. Lock the motor plate adjustment nuts in place.

4. Ensure pulleys are properly aligned.

When replacing belts, replace the entire set. After initial replacement and tensioning, recheck belt tension after a few days. New belts require a break-in period. Never use belt dressing on any belts.

Drive Alignment

Pulley alignment is adjusted by loosening the motor pulley setscrew and by moving the motor pulley on the motor shaft. Fig. 9 illustrates correct and incorrect pulley alignment.

Correct Incorrect

Wheel and Shaft Maintenance

Periodically inspect the shaft and wheel for dirt buildup, corrosion, and signs of excess stress or fatigue. Clean the components. If the wheel is removed for any reason, make sure that it is securely attached to the shaft before restarting the fan.

Arrangement 8 Shaft Flexible Couplings

Coupling alignment should be checked after installation and prior to start up. Alignment is set at the factory, but shipping, handling, and installation can cause misalignment. Check for misalignment between the coupling halves. Parallel and angular misalignment and separation gap are shown

in Figure 11. Refer to coupling manufacturer’s installation

instructions for allowable misalignment and separation gap tolerances. When correcting for misalignment using shims, the shims should only be located under the motor. Do not place shims under the shaft bearings. A dial indicator or laser can be used for alignment where greater precision is required. After aligning procedure, check for tightness of all coupling component pieces and ensure that they are clean from dirt and debris.

Separation

Incorrect Incorrect

Figure 9 - Pulley Alignment

A recommended method of inspecting the pulley alignment is shown in Figure 10. With the shorter leg of a

carpenter’s square or other straight

edge lying along the case of the motor, adjust the position of the motor

pulley (or the motor) until the longer

leg of the square is parallel to the belt.

Motor Maintenance

The three basic rules of motor

maintenance are:

Figure 10

1. Keep the motor clean.

2. Keep the motor dry.

3. Keep the motor properly lubricated.

Blow dust off periodically (with low pressure air) to prevent

motor from overheating.

Some smaller motors are lubricated for life. Lubrication

requirements are normally attached to the motor. Use the

motor manufacturer’s recommendations for relubrication. If

this information is not available, the following schedule may be used. Motors less than 10 HP running about eight hours a day in a clean environment should be lubricated once every

ve years; motors 15 to 40 HP, every three years. For motors

in dusty or dirty environments or running 24 hours a day: divide the service interval by 4. Do not over lubricate.

Angular

Misalignment

Parallel

Misalignment

Figure 11 - Flexible Couplings

Drainage Detail

All DHK fans come as standard with outlet drains due to the possibility of water or condensation that may occur. Proper disposal of water must occur by connection of drain outlet to

a drainage system (by others). Piping must have adequate pitch for proper runoff and be supported (if needed) to prevent the possibility of sagging and overow. The trap should be lled before start-up.

Fan Drain

Dimension of A, B, C: Inches

Figure 12 - Drainage Detail

A: Must be greater than system static pressure.

B: Must be greater than 1/2 of the system static pressure.

C: 1” water seal.

M.K. Plastics Corp. Montréal, Québec www.mkplastics.com Page. 4

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Speed [rpm] 500 1000 1500 2000 2500 3000

Size

1225

1500

1825

2225

1225

6 6 5 3 3 2

1500

6 6 5 3 3 2

1825

6 6 5 3 3 2

2225

6 6 5 3 3 -

2450

6 4 4 3-1/2 2-1/2 -

2700

6 4 4 3-1/2 2-1/2 -

3000

5 4 3 2-1/2 - -

3300

5 4 3 2-1/2 - -

3650

5 4 3 - - -

4025

5 4 2-1/2 - - -

4450

4-1/2 3-1/2 2-1/2 - - -

4900

4-1/2 3-1/2 - - - -

5425

4-1/2 3-1/2 - - - -

6000

4-1/2 3-1/2 - - - -

Relubrication Schedule [Months]

For Bearings With No Grease Fittings

For Bearings With Grease Fittings

Relubrication is not required. Bearings are factory charged with the correct amount of grease and do not require further grease charge.

Table 2 - Relubrication Schedule [Months]

Fan Bearing Lubrication

Proper lubrication of the fan drive bearings helps assure maximum bearing life. DHK fans come with three types of fan bearings:

1. Self-Lube pillow block ball bearings (1225-2225), which

do not require re-greasing. No grease ttings.

2. Air Handling Heavy Duty ball bearing pillow blocks

(1225-2225), which do require re-greasing. With grease ttings - see schedule on Table 2.

3. Spherical split pillow block bearings (2450-6000), which do require re-greasing through a grease tting on the

outer housing and should be lubricated by the schedule, Table 2.

However, every installation is different and the frequency of relubrication should be adjusted accordingly. On high moisture applications, the lubrication frequency may need to be doubled or tripled to adequately protect the bearings. Double the relubrication frequency on fans with vertical shafts.

Observation of the conditions of the grease expelled from the bearings at the time of relubrication is the best guide as to whether regreasing intervals and amount of grease added should be altered.

Greases are made with different bases. There are synthetic base greases, lithium base, sodium base, etc. Avoid mixing greases with different bases. They could be incompatible and result in rapid deterioration or breakdown of the grease.

All bearings are lled with a lithium-based grease before

leaving the factory. When the fans are started, the bearings may discharge excess grease through the seals for a short period of time. Do not replace the initial discharge because leakage will cease when the excess grease has worked out. Sometimes the bearings have a tendency to run hotter during this period. There is no reason for alarm unless it lasts over

48 hours or gets very hot (over 200°F). When relubricating,

use a sufcient amount of grease to purge the seals. Rotate

bearings by hand during relubrication.

Table 2 is for shaft bearings on belt drive and direct drive

arrangement #8 fans, motor bearing lubrication should be per

the motor manufacturers instructions.

Suggested initial greasing interval - remove bearing cap and observe condition of used grease after lubricating. Adjust lubrication frequency as needed. Hours of operation, temperature, and surrounding conditions will affect the relubrication frequency required. ‘If bearings need to be re

packed, remove old grease, pack bearing full and ll housing reservoirs on both sides of bearing to bottom of shaft.’

Lubricate with a multipurpose roller bearing NLGI No. 2 having

rust inhibitors and antioxidant additives, and a minimum oil

viscosity of 500 SSU at 100ºF. Some greases having these

properties are:

1. Shell - Alvania No. 2 Mobil

2. Mobilith AW2/Mobilith SHC100

3. Texaco - Premium RB2

4. American - Rykon Premium 2

Lubricate bearings prior to extended shutdown or storage

and rotate shaft monthly to aid corrosion protection.

Fan Bearing Replacement

Figure 13

Split Pillow Block

Figure 14

Solid Pillow Block

M.K. Plastics Corp. Montréal, Québec www.mkplastics.com Page. 5

Page 6

Removal of Wheel, Shaft & Bearings -

1. Mark the position on the shaft of both bearing races,

setscrews (if applicable) and the wheel and sheave. If

you are replacing the shaft as well, these marks will give you reference.

2. Mark the location and orientation of the inlet cone and sleeve to the casing and remove, this will give you access to the wheel. Remove the drive sheave from the shaft

3. Start wheel removal by unscrewing the front protective cap and then the nut, washers and threaded stud assembly that holds the cap to the fan shaft. The exposed bushing has hex screws that secure the bushing to the

shaft; they are situated on the front face of the bushing.

Unscrew the hex screws, remove and screw back into the other exposed holes of the bushing. By doing this you are pushing the bushing out. Remove and then use a 2-jaw puller to extract the bushing if needed. When the bushing is out, the wheel and hub assembly can now be

removed from the fan shaft. Note: DHK 1225 to 1500

sizes do not have bushings, the wheel is held in place to the shaft with the threaded rod assembly only.

4. Unbolt the bearing housing hold-down bolts and remove the shaft and bearings as one unit. Keep any existing shims in place.

5. Unbolt the top housing section and remove the bearing assemblies from the shaft. A suitable puller may be required, or tap on the bearing with a wood block and hammer to remove. If the bearings are attached with set screws, unscrew and slide the assembly off as one piece.

6. If the existing shaft is being used, check the shaft for nicks, burrs and damage. Remove any anti-corrosion coating with a suitable degreaser and wipe clean.

Bearing Replacement [Split Housing Bearings With Adapter Sleeves] -

1. Split pillow block bearings come in kits with bearings,

adapter sleeve, locknut, lock washer and xing rings for the rear xed bearing. NOTE: replacement bearings will

be shipped temporarily assembled on a shaft.

2. Remove the top half of the bearing housing to expose the bearing seat.

3. Place the lower half of the bearing housings in position

on the stand and tighten the xing bolts.

4. Spherical split pillow block bearings use synthetic rubber

seals that come in split (half) sections. One half should

be inserted into the lower bearing housing on both sides and some grease applied prior to the bearing assembly.

5. Place the bearings in the lower half of the housings with the larger sides of the bores facing towards the shaft ends.

6. Slide the adapter sleeves through the bearings, ensuring that the threads are facing each other.

7. Install the lock washers on the adapter sleeves with inner prong of washer in a slot on the adapter sleeve. Install the locknut on both bearings with the chamfered face facing the bearing, but do not tighten.

8. Slide shaft through both bearing assemblies. If the bearing locks to the shaft, tap gently on the adapter sleeve to loosen.

9. To hold the shaft in place during wheel mounting, clamp the sheave end of the shaft to the edge of the stand.

10. Install the wheel and bushing on the shaft. Install the inlet cone in its original location. Position the wheel correctly

by moving the shaft axially in the bearing assemblies.

11. Install xing rings on the rear bearing (closest to sheave).

Move shaft axially so that the xing ring may be inserted

between housing shoulder and bearing outer ring.

12. Tighten locknuts to fasten the bearings to the shaft, using a spanner. While tightening, regularly measure the internal bearing clearance between the most vertical unloaded roller and outer ring with a feeler blade. When

required clearance is obtained (check table), tighten

locknut until the closest washer tab meets a slot on the locknut.

13. Fill the lower housings with grease until the rollers are covered.

14. Carefully align the top part of the housing with the dowel pins and tighten bolts, ensuring that the upper seals are in place. Make sure that the split housing is paired only with its original top half, as these parts are not interchangeable from one housing to another.

Bearing Replacement [Closed Housing Bearings With Setscrews] -

1. Making sure that the set screws are not protruding from the inner bearing rings, slide the bearings directly onto the shaft. If using an old shaft, make sure the bearings are not mounted on a worn section. Tapping the inner ring face with a soft driver might be required.

2. The outer ring of the bearing is spherical and swivels in the housing to compensate for misalignment. Secure

the housing to the stand with the xing bolts, but do not

fully tighten.

3. Install the wheel on the shaft. Install the inlet cone in its original location. Position the wheel correctly by moving the shaft axially in the bearing assemblies.

4. Tighten the setscrews on the bearings to secure the

shaft. Refer to torque chart on Page 7.

5. Rotate the shaft by hand to allow the bearing outer rings to nd their center of free movement.

Test Run -

1. Re-install the sheave and adjust the belt tension.

2. Test run and retighten all setscrews and xing bolts; trim balance as necessary.

Changing Shaft Speed

All belt driven fans with motors up to and including 5 HP

are equipped with variable pitch pulleys. To change the fan speed, perform the following:

1. Loosen setscrew on driver (motor) pulley and remove key, if equipped.

2. If the pulley has multiple grooves, all must be adjusted to the same width.

3. After adjustment, inspect for proper belt tension.

4. To reduce speed, open the pulley in order that the belt

rides deeper in the groove (smaller pitch diameter).

5. To increase speed, close the pulley so that the belt rides higher in the groove (larger pitch diameters). Make sure

the maximum fan RPM and motor HP is not reached.

M.K. Plastics Corp. Montréal, Québec www.mkplastics.com Page. 6

Page 7

Size

Set Screw /

Bolt Torque

Size

Pillow Block

Bearing

Set Screw /

Bearing Cap

Bolt Torque

Mounting Bolt

304 SS Bolt

Torque

316 SS Bolt

Torque

1225 RHP, MP1 60 in-lbs 3/8-16UNC, 1.75L 236 in-lbs 247 in-lbs

1500 RHP, MP1 60 in-lbs 3/8-16UNC, 1.75L 236 in-lbs 247 in-lbs

1825 RHP, MP1-7/16 110 in-lbs 1/2-13UNC, 2.25L 517 in-lbs 542 in-lbs

2225 RHP, MP1-7/16 110 in-lbs 1/2-13UNC, 2.25L 517 in-lbs 542 in-lbs

2450 NSK,SNN,1-11/16 389 in-lbs 1/2-13UNC, 1.75L 517 in-lbs 542 in-lbs

2700 NSK,SNN,1-11/16 389 in-lbs 1/2-13UNC, 2.25L 517 in-lbs 542 in-lbs

3000 NSK,SNN,2-3/16 673 in-lbs 5/8-11UNC, 2.5 L 1110 in-lbs 1160 in-lbs

3300 NSK,SNN,2-3/16 673 in-lbs 5/8-11UNC, 2.5 L 1110 in-lbs 1160 in-lbs

3650 NSK,SNN,2-3/16 673 in-lbs 5/8-11UNC, 2.5 L 1110 in-lbs 1160 in-lbs

4025 NSK,SNN,2-7/16 673 in-lbs 5/8-11UNC, 2.75L 1110 in-lbs 1160 in-lbs

4450 NSK,SNN,2-15/16 1682 in-lbs 3/4-10UNC, 3 L 1530 in-lbs 1582 in-lbs

4900 NSK,SNN,2-15/16 1682 in-lbs 3/4-10UNC, 3 L 1530 in-lbs 1582 in-lbs

5425 NSK,SNN,3-7/16 3275 in-lbs 1-8UNC, 3.75L 3400 in-lbs 3595 in-lbs

6000 NSK,SNN,3-7/16 3275 in-lbs 1-8UNC, 3.75L 3400 in-lbs 3595 in-lbs

MSK

Bushing

Cap Screw Torque

H 1/4 x 3/4 95 in-lbs

P 5/16 x1 192 in-lbs

Q 3/8 x 1-1/4 348 in-lbs

R 3/8 x 1-3/4 348 in-lbs

S 1/2 x 2-1/4 840 in-lbs

U 5/8 x 2-3/4 1680 in-lbs

W 3/4 x 3 3000 in-lbs

P1-P3 5/16-18 UNC 80 in-lbs

Q1-Q3 3/8-16 UNC 143 in-lbs

Bushing Tightening for Aluminum Hub