L A N D Y S C R E W P U M P S

L A N D Y S C R E W P U M P S

WIDE APPLICATION POSSIBILITIES

Applications for the screw pump are countless:waste water treatment plant influent pumpingstationswaste water treatment plant intermediatepumping stationsreturn sludge pumping stationsirrigation projectsdrainage projectsreclamation of wetlandscirculation within aeration systemswild water tracks in fun parksindustrial applicationsstorm water applications

INTRODUCTION

This leaflet gives an overview of the services and products of Landustrie Sneek BV regardingscrew pumps and screw pump installations.Landustrie has broad experience in this field. For nearly 100 years Landustrie has designed,manufacturered, supplied, erected and main-tained many types of screw pump configurations.Since the early eighties Landustrie has hadavailable a fully automated screw pump selectionprogram which can be used to select theoptimum screw pump for a particular application.The program is based on a large number of tests,with an equally large number of variables, in theLandustrie test facility. The accompanyingcalculation method has, for several of our orders,been approved by Germanische Lloyds.In addition, Landustrie has developed over manyyears their specific pump knowledge base, whichis continuously updated by means of R&Dactivities and the purchase of the latest techno-logy – for example their computer program usingFinite Element Analysis methods. This knowledgeand experience ensures Landustrie’s place asone of the leading manufacturers in the world ofscrew pump installations.

PRINCIPLE OF THE SCREW PUMP

The principle of the screw pump is an inclinedtube, provided with blades, which by rotatinglifts the medium to a higher level.

CROSS-SECTION Z-Z

TERMINOLOGY OF THE SCREW PUMP

The picture shows the most common definitionsregarding screw pump installations

LANDY SCREW PUMPS

Screw pumps and screw pump installations ingeneral are characterized by the followingfeatures:

open, clog-free, simple and robustconstructionhigh efficiency, low maintenance, lowoperational costshighly reliable, long lifetime and virtually nowear (no spare units required)automatic adjustment of the pump capacityas a function of the incoming flowoperating in a wide range, with a capacityfrom 10 to 11.500 l/s and lift from 0 to 25 mchanges in the capacity are easy and, ifnecessary, stepless insensitive to supply conditions and also(because of the low rpm) no problems withcavitation

OPEN, CLOG-FREE, SIMPLE AND ROBUSTCONSTRUCTION

Depending on the medium (in most cases raw waste water) several kinds of contamination can occur. The screw pump has an importantadvantage, which is that due to its openconstruction, screenings plant can, if required,be situated after the screw pump, resulting inlower civil costs of the total installation.By means of its advanced screw pump selection program, Landustrie is capable ofselecting screw pumps which, in many cases,will have two flights. This offers advantages inrespect of less deflection because of the lower bending moment, lower welding tension, and lower resultant forces on the civil construction. This in turn will allow biggerlifts. As a standard, Landustrie, based on nearly a century’s experience, allows for abending moment of 20 N/mm2 maximum, and a maximum deflection of L/2500. The actual tensions can be ascertained byinputting the data into our Finite ElementAnalysis program.All selected screw pumps can be supplied in either a coated steel or stainless steel version in AISI304 or AISI316. Other exoticmaterials are also possible.

Cross-section Z-Z Chute point

Max.pumping

point

Touch point

Fillingpoint

D = DiameterJ = No. of flightsN = SpeedS = Pitch

L = Flight lengthH = Nominal liftF = Tension� = Inclination

L A N D Y S C R E W P U M P S

HIGH EFFICIENCY, LOW MAINTENANCE,LOW OPERATIONAL COSTS

Because of the contamination in the medium, the efficiency of screw pumps for thisapplication will be much higher than for othertype of pumps. Moreover, the screw pump isideally suited to cope with variations in theincoming flow whilst working at a nearlyconstant efficiency (see under automaticadjustment of pump capacity). Also, the lowernumber of revolutions of screw pumps adds tothe relatively high efficiency of the overallinstallation.Because the complete screw pump installation is built up from an electric motor, gearbox, upperand lower bearing, the maintenance is limited toa yearly oil change and periodic checking of allgreasing points. All these factors lead to verylow operational costs for Landustrie screw pumpinstallations.

HIGHLY RELIABLE, LONG LIFETIME ANDHARDLY ANY WEAR (NO SPARE UNITS REQUIRED)

The robust construction of the screw pump body and both bearings, the use of standardcomponents such as electric motors andgearboxes at low revolutions gives the screwpump a unique reliability record. With intensiveuse a lifetime of 20 years is normal. Even screwpumps which have been in operation for morethan 40 years occur quite regularly. An additional advantage of the extreme reliability is that no spare unit needs to beconsidered at design stage.

AUTOMATIC ADJUSTMENT OF THE PUMPCAPACITY AS A FUNCTION OF THEINCOMING FLOW

The capacity of the screw pump is automaticallyadjusted in the event that the incoming flow islower than the screw pump capacity. When theincoming flow is greater than the pump capacity,the discharge will be limited to the screw pumpcapacity. Because of this equable flow regime, a screw pump is extremely suitable as aninfluent pump for a waste water treatment plant,as hydraulic overloading is prevented.

incoming flow at filling point

incoming flow above filling point

incoming flow below filling point

Screwdiameter

(mm)

Max.speed(r.p.m.)

Capacitymax

(m3/sec.)

30°

Homax.(mm)

Capacitymax

(m3/sec.)

Homax.(mm)

Capacitymax

(m3/sec.)

Homax.(mm)

35° 38°

300 118 0,016 2800 0,012 3200 0,011 3500

450 98 0,041 4000 0,033 4600 0,029 5000

600 75 0,082 4700 0,066 5400 0,059 5900

800 62 0,154 5500 0,125 6300 0,0112 6900

1000 53 0,272 6700 0,218 7700 0,196 8400

1250 46 0,430 7700 0,360 8900 0,312 9700

1500 40 0,690 8600 0,556 10000 0,500 10900

1800 36 1,080 9800 0,866 11400 0,777 12500

2100 32 1,500 9200 1,210 10500 1,087 11500

2450 29 2,210 8000 1,770 9100 1,591 10000

2800 26 2,980 10500 2,390 12100 2,150 13300

3200 24 4,070 10600 3,273 12100 2,940 13300

3600 22 5,360 11000 4,306 12600 3,860 13800

4050 21 7,060 11400 5,670 13000 5,090 14200

4500 19 9,000 11700 7,240 13300 6,500 14600

5000 18 11,530 12000 9,260 13600 8,320 14900

WIDE DESIGN RANGECAPACITY FROM 10 TO 11.500 L/SLIFT FROM 0 TO 25 M

Every single screw pump is specifically designed for each project. Because of that thereis always an optimum relationship betweenfunction and design. This can vary between acapacity of 10 and 11.500 l/s. As regards the lift,the possibilities are practically unlimited whenscrew pumps are installed in serial order. Theadjacent table shows an indicative overview ofthe most common options. Also screw pumpinstallations with different inclinations, whichwere quite often used in the past, can be quotedon request.

CHANGES IN THE CAPACITY ARE EASYAND, IF NECESSARY, STEPLESS

When the capacity of the screw pump must be adapted to very specific conditions, forwhatever reason, then this is normally easy to fixby using either a two-speed motor or a variablefrequency drive (VFD). In the case of fixed rpmone can consider, for longer and biggerdeviations, changing the pulleys of the V-belttransmission. In nearly all cases the pumpremains within its effective range.

Fillingpoint

Touch point

Pump efficiency

Pump capacity

Discharge and efficiencyat various inlet levelsbelow filling point

INSENSITIVE TO SUPPLY CONDITIONSAND, BECAUSE OF ITS LOW SPEED, NO PROBLEMS WITH CAVITATION

Because of the low revolutions and the nature of the screw pump no special demands have tobe met regarding the inlet channel of the screwpump. The screw pump is, contrary to othertypes, insensitive to supply conditions.Especially at higher revolutions critical supplyconditions could lead to cavitation, which inpractice fairly often occurs with competingpump types.

Screw pumps in serial order

DRIVE-UNIT OPTIONS

Depending on the local circumstances there is a choice of different drive-unit arrangements.Different options are shown schematically in the drawing below. Deviations from theseguidelines is, of course, possible, if so required.

TROUGHS

In choice of troughs there are several options.First of all there is the classic concrete trough,for which the screw pump itself is used to groutthe trough to its final shape, working at lowspeed and using a special mortar. When thisspecific know-how is not available it is possibleto order either a screw pump with a steel castingmould which is removed after the concrete hasbeen poured, in this way leaving the correctclearance between the screw pump and theconcrete, or with a cast-in steel (or stainlesssteel) trough, which will remain in the concrete.For special applications there is also the optionof a fully self-supporting steel trough or acompletely pre-fabricated screw pump, includingtrough bearings and drive-unit. The last optionhas the advantage that installation time isextremely short. For smaller screw pumps, a pre-fabricated pump can be installed as a tubescrew pump.

RESEARCH AND DEVELOPMENT

For many years Landustrie has been active inresearch to improve the screw pump evenfurther. The most recent results are the Eco-friendly lower bearing, which has been tested for over 10 years, amongst other locations at the Waste Water Treatment Plant of Zwanenburg(The Netherlands) as well as the use of the Finite Element Analysis on the Landustrie screw pump designs.

P � 30 kWP � 37 kW

P � 55 kWP � 45 kW

cast-in trough

concrete trough

tube screw pump

pre-fabricated screw pump

L A N D Y S C R E W P U M P S

LOWER BEARINGS

For the lower bearings Landustriehas four different standard types. The most recent is the Landy Eco-friendly lower bearing, with a numberof specific advantages (see theadjacent 3-D sketch).In the table we have compared thefour different Landustrie lowerbearings. All lower bearings, of anytype, only have to absorb radialforces. The lower bearing alsoabsorbs the length changes of thescrew pump due to differences intemperature.

Completely enclosed unit

No maintenance and no grease costs

3-dimensional self-aligning

Corrosion-freecast iron housing

Lower investment

No spare parts required

Exchangeable withexisting bearings

No grease pump andgrease lines required

Easier to install

Eco-friendly lubricated for lifetime of the bearing

High-performance seal

Eco-friendly Conventional Medium Heavy Duty

Lubrication Lifetime Grease Medium Grease

Grease filling ● ●

Grease return line NA On request NA ●

Maintenance required ●

3D-self-aligning ● ●

Water quality low low high low

Installation time low average low average

Heavy duty ●

Exchangeability with existing bearings ● ● ●

Investment low medium low high

Operational costs low medium low medium

Lifetime average average average long

LOWER BEARING SELECTION TABLE

ECO-FRIENDLY LOWER BEARING

wall-mounted bearing

CONDITION MONITORING

All existing and new screw pump installationscan be equipped with a condition monitoringsystem which on-line continuously suppliesdetails about both the upper and lowerbearings.This monitoring system is based on acousticemission sensors which detect possibleproblems at a very early stage. Not onlyoperating and maintenance costs will bereduced, but also the exploitation and usabilityof the installation will be increased.

UPPER BEARINGS

For the upper bearing Landustrie can offer thechoice between two different versions; awall-mounted or a foot-mounted upperbearing.The preference is normally for the wall-mounted upper bearing, firstly becausethe forces on the civil construction willbe better absorbed, and secondlybecause an odour-tight separation iscreated between the screw pump and theroom in which the drive-unit is installed. foot-mounted bearing

LANDY SCREW PUMPS BECAUSE...

Besides the general characteristics of the screwpump, the Landy screw pumps are distinguishedby:

In other words a first class product with

screw pump technology

Nearly 100 years experience

Efficient design - - Usually 2 flights- Limited deflection- Limited occuring tension- High efficiency

Ongoing R&D

Finite Element Analysis

Full in-house manufacturing

Totally reliable manufacturing schedulesand delivery times

Endplates- Fully watertight by means of caps

over threads of connection bolts- Fully parallel and centric manufacture

using special lathesReinforced leading edges of flights

Manufactured with permanent lifting eyesand balancing weights

Fully qualified welders- X-ray or ultrasonic- Welding Shop Approval

Coating. All required coatings areapplied professionally, and can besupplied with additional requirementsregarding sand, salt or pH.

Basic material of bearing shafts is nodularcast iron

Use of fully self-aligning bearings

World-wide service with local support

Superb after-sales service

Erection with competent and experienced Landustrie mechanics. Onrequest, we can also offer fullsupervision of installation.

STATE-OF-THE-ARTSTATE-OF-THE-ART

L A N D Y S C R E W P U M P S

01-2

007-

1500

EN

G.

Landustrie Sneek BVP.O. Box 199NL-8600 AD SneekThe Netherlands

Tel. +31 515 - 48 68 88Fax +31 515 - 41 23 98e-mail info@landustrie.nlwebsite www.landustrie.nl

Office address Pieter Zeemanstraat 6, Sneek

Watertechnology

REFERENCES

During the nearly 100 years of their existenceLandustrie has undertaken some 5000 screw pumpprojects, which are all unique in terms of designand execution, varying in power from 1 to 600 kWand in diameter from 10 cm to 5 meter, and inlength from 50 cm to 25 m. All these projects haveadded to the vast amount of knowledge andbackground information built up over the yearsregarding the design, manufacturing and installationof screw pumps. For every new project, you, as ourcustomer, are using this inexhaustible amount ofexperience.You will find some of our most recent projects inthe adjacent photo collage.

COVERS

On request Landustrie can cover the installationwith a modular light weight synthetic coverconstruction. Advantages are:

protection of the screw pump against thermalexpansioncreates a safe working environmentreduces the level of noise production

Hamburg, Germany

Zagreb, Croatia

Veneriete, The Netherlands (renovation)

Dublin, Ireland

Indianapolis, USA

Lynetten, Denmark

Cologne, Germany

Olifantsvlei, South Africa