Concrete Batching Plant

Concrete Batching Plants are used for manufacturing high-quality concrete in a variety of construction applications, like buildings, roads, bridges, airports, and many others, and integrates materials storing, weighing, and mixing processes.
It is a machine that combines various ingredients like aggregates, sand, water, cement, and additives. These components are first weighed individually and then combined to prepared ready-mix concrete

1. Concrete Batching Plant
Presentation by: Parvez Ahmad Hashmat
Entry#: 2019CET2027
Course: CVL776
Submitted to: Professor A.K. Jain
Indian Institute of Technology-Delhi-2020

2. Contents
•Introduction
•Types of batching plants
•Dry mix batching plant
•Wet mix batching plant
•Comparison between dry mix and wet mix batching plants
•Batch plant Operations
•Batch Plant Components
•Transit Mixer (Dry Batch) Plant Discharge
•Aggregate Handling System
•Mixer & Central Dust Collector
•Central Mix Plant Material Discharge and Sequencing
•The Factors to Consider when Choosing a Satisfying Concrete Plant
•References

3. Introduction
ConcreteBatchingPlantsareused
formanufacturingofhigh-quality
concreteinavarietyof
constructionapplications,like
buildings,roads,bridges,airports
andmanyothersandintegrates
materialsstoring,weighingand
mixingprocesses.
Itisamachinethatcombines
variousingredientslikeaggregates,
sand,water,cement,andadditives.
Thesecomponentsarefirst
weighedindividuallyandthen
combinedtopreparedready-mix
concrete
3

4. Introduction
Concretebatchingplantmainlyconsistsofstoring,
weighing,conveying,mixingandcontrollingsystemsand
othersupportingfacilities.
Aconcreteplanthasanassortmentofpartsasbelow:
mainplantstructure,concretemixer,cementsilos,screw
conveyors,beltconveyor,weighingsystems,fluidsupply
system,airsupplysystem,electroniccontrolsystem,dust
collector,batchingmachineandcontrolroom.
4

5. Types of Batching Plants
Therearevarioustypesofready
mixconcreteplantswhichmost
ofthemdesignedforspecific
locationsorcircumstances.
Overalltherearetwomain
typesofconcreteplants:
•Drymixbatchingplants
•Wetmixbatchingplants
Inaddition,half-wetbatch
plantandcombinationbatch
plantsarealsoavailable.
5

6. Dry Mix Batching Plants
Thistypeofreadymixconcreteplantproduces
uniformconcretemixthroughthemixingactionof
thetruckmixer.Themixingactionisbasicallya
twofoldmechanism.
Drymixconcretebatchingplants,havesand,gravel,
andcementfeedingtobatchingplantthatpassthe
numericalormanualscale.Thenalltherawmaterials
aredischargedintoachuteintothetruck.Atthe
sametime,thewaterisweighed,orvolumemetered
anddischargedintothemixertruckthroughthesame
chargingtank.Atlast,allthematerialmixedand
transportedtothesite.
6

7. Dry Mix Batching Plants
Drymixconcretebatchingplantismoresuitableforthose
constructionprojectswhichrequirelargeamountof
concrete.Suchas:waterresource,electricpower,highway,
harbor,bridge,airport,largeprecastproductsplantand
commercialconcreteplants.
7

8. Dry Mix Batching Plants
Plant Components
• Ground Hopper
For feeding of raw material, coarse and fine aggregates
• Movable Inclined Conveyor
To convey the coarse and fine aggregate to the designated
storage compartment
• Aggregate Storage Bin
For storage on top of the aggregate weighing bin
• Aggregate Weighing Bin
For weighing of the coarse and fine aggregates
• Shooting Conveyor
To convey the coarse and fine aggregates at high speed which
shoot directly into the mixer drum of the mixer truck
• Cement Storage Silos
For storage of cement -OPC, PFA and Slag Cement
8

9. Dry Mix Batching Plants
Plant Components:
• Cement Weighing Bin
For weighing of various cement
• Water Weighing Bin
For weighing of water
• Admixtures Weighing Bin
For weighing of admixtures
• Control Room
To provide staff on the control of the production
• Water Storage Tank
For water storage
• Aggregate Stockpile
For storage of cement -OPC, PFA and Slag Cement
9

10. Dry Mix Batching Plants
Plant Components
• Slump Check Platform
For concrete slump check
• Wheel Loader
For material handling from aggregate stockpiles to ground hopper
• Mixer Truck
For mixing of concrete and delivery of finished products to customers
• QC Laboratory
For quality control and testing
• Power Supply
To provide power supply to the plants and other facilities either by
TNB or generator set
• Waste Material Storage
To collect all waste material and disposed to designated area
10

11. Dry Mix Batching Plants
Plant Components
11

12. Dry Mix Batching Plants
Process Flow of Dry Mix Plant
The process flow of the entire dry mix plant operation
is as illustrated below:
Cycle Time per Load = Batching + Mixing & Slump
Check + Delivery + Discharging + Return + Queuing
The total time for above process will vary depending
on site conditions for each project.
12

13. Process Flow of Drying Mix Batching Plant
13

14. Dry Mix Batching Plants
Advantages of Dry mix batching plant:
-It has higher capacity and lower energy consumption
because concrete can be mixed without water
-The cooperation between the dry batching plant and the
mixer truck can increase productivity and save time.
-The fresh concrete can be used because of the mixer
trucks arrive at the construction site.
-It shortens the construction and enhances productivity.
-It’s got lower power consumption when compared to the
wet mix plant.
14

15. Dry Mix Batching Plants
Advantages of Dry mix batching plant:
-Operating costs of dry-batch concrete plants are
relatively low
-Allows concrete to be mixed more efficiently.
-It could be the short time period of maintenance
needed when compared with wet mix plants.
-As in other mixing plants, such as mobile and
stationary concrete plants, the dry concrete plant is also
automated.
15

16. Wet Mix Batching Plants
WetmixConcretePlantputs
sand,gravel,air,admixtures,fly
ash,cement,etc.includingwater
intoaconcretemixeratacentral
location.Afterthemixing
process,theconcretecanbe
dischargedintoamixertruckor
agitatortotransportconcreteto
theconstructionsite.Thewet
batchconcreteplantisnecessary
inthecasemortarproductionis
required.
16

17. Wet Mix Batching Plants
Thewetmixconcretebatchplantcanbedividedinto
stationaryconcreteplantandmobileconcreteplant.Asthe
namesuggests,mobileconcreteplantiseasiertomovethan
thestationaryconcreteplant.Italsocanbedividedintothe
hoppertypeconcreteplantandbelttypeconcreteplant
accordingtothefeedingmethods.What’smore,bothofthem
havevariouskindsofsizessothatyoucanchooseproducts
accordingtothedifferentrequirementsofmatters..
17

18. Wet Mix Batching Plants
Plant Components
• Ground Hopper
For feeding of raw material, coarse and fine aggregates
• Aggregate Weighing Bin
For weighing of various types of aggregates
• Horizontal Conveyor
To convey the weighed coarse and fine aggregates to Inclined Conveyor
• Inclined Conveyor
To convey the weighed coarse and fine aggregates to the aggregate
transfer bin
• Aggregate Transfer Bin
For storage on top of the Mixer
• Mixer
For mixing of concrete
18

19. Wet Mix Batching Plants
Plant Components
• Concrete Holding Hopper
For holding of finished product before discharging into mixer truck
• Cement Storage Silos
For storage of cement -OPC, PFA and Slag Cement
• Cement Weighing Bin
For weighing of various cement
• Water Weighing Bin
For weighing of water
• Admixtures Weighing Bin
For weighing of admixtures
• Control Room
To provide staff on the control of the production
• Water Storage Tank
For water storage 19

20. Wet Mix Batching Plants
Plant Components
• Aggregate Stockpile
For storage of coarse and fine aggregates
• Wheel Loader
For material handling from aggregate stockpiles to ground hopper
• Mixer Truck
For mixing of concrete and delivery of finished products to customers
• QC Laboratory
For quality control and testing
• Power Supply
To provide power supply to the plants and other facilities either
by TNB or generator set
• Waste Material Storage
To collect all waste material and disposed to designated area
20

21. Wet Mix Batching Plants
Plant Components
21

22. Wet Mix Batching Plants
Process Flow of Wet Mix Plant
Theprocessflowoftheentiremodularwetmix
plantoperationisasillustratedbelow:
CycleTimeperLoad=Batching+Delivery+
Discharging+Return+Queuing
Thetotalcycletimeperloadwillbelesscomparingto
drymixastheprocessofmixingisdonebythemixer
andmixertruckisonlyusedfordeliveryand
dischargingatsite.
22

23. Advantages of Wet Mix Batching Plant
Weselecttwinshaftconcretemixertoensurethe
mixingqualityandimprovetheproductcapacity.
Thewetbatchconcreteplantisusefultomediumor
largescaleconstructionproject.
Theideasofdesignarefocusonthesafetypoints,high
capacityandenvironmentfriendly.Onbothsidesof
aggregatefeedingsystemandcementsilos,thesafety
fencesareprepared.Safetyfencesonbothsidesof
feedingsystemcanpreventthedropofsome
aggregates.Thefencesonthecementsilosarestepsto
climbtothetopofsilos.
23

24. Advantages of Wet Mix Batching Plant
Thearchbrokensysteminthelowerpartofcementsilohelps
toavoidtheaccumulationofpowerandcementblockage,
therefore,theproductiveratewillbeincreased.
Dusteliminationsystemhelpstoreducethepollutionduring
workingprocessofconcreteplant.Thetopofthecement
tankisequippedwithanelectricdusteliminationdevice
whichcaneffectivelyabsorbthesuspendedparticlesinthe
silos.Asaresult,itcanreducethepollutiontothe
surroundingenvironment.
Wastewatertreatmentsystemalsoisimportanttothe
environment.Inordertoprotectourenvironmentand
developtheeconomyinhealthymethod,wemustdealwith
thewastewaterproperly;sowedesignourplantwiththe
wastewatersystem.
24

25. Comparison Between Dry Mix and
Wet -Mix Batching Plant
Comparison of Process Flow
ItemDescription Dry Mix Wet Mix
1 Batching 5 min 5 min
2 Mixing 15 min -
3 Delivery to site 30 min 30 min
4 Discharging at site 45 min 45 min
5 Return to plant 30 min 30 min
6 Queuing at plant 10 min 10 min
7 Total Cycle Time per Load135 min 120 min
8 (Mixer) Truck Required 18 16
25

26. Comparison Between Dry Mix and
Wet -Mix Batching Plant
Similarities
Bothdrymixconcreteplantandwetconcrete
batchingplantconsistoftheweighingsystem,
aggregatesupplysystem,mixingsystem,control
system,cementsiloandothersubsystems.
Bothofthemcanachievethesemiautomationand
fullautomation.Theautomaticdegreecanbe
designedaccordingtotherequirementsof
customers.
Environmentfriendlyandsafetyaretheirrelevant
ideasintheprocessofdesignandmanufacture
26

27. Comparison Between Dry Mix and
Wet -Mix Batching Plant
Differences
Wecansaythattheonlydifferencebetweendrymix
plantandwetmixconcretebatchplantiswater:dry
mixconcreteplantjustmixthematerialswithoutwater,
andwaterwillbeaddedduringthetransportation
processbytheconcretemixertruck;thewetmix
concreteplantisaperfectequipmenttoprovideready
mixconcrete.
Thedrymixconcreteplantmustcooperatewithmixer
truck,soitcanmakesurethatthefreshconcretecan
beprovidedwhentheconcretereachesthe
constructionscene.
27

28. Batching Plant Operations
Usuallyastationarytypeconcrete
batchingplantisbiggerinsize.Its
operationismoreorlesssimilarto
themobileversion.
Stationaryversionispreferredby
customerswhowanttoproduct
concreteatasingleplaceand
portableversionispreferredby
peoplewhowanttoshiftsites
moreoften.
28

29. Batching Plant Operations
Working principle of concrete batching plant is dependent on five
primary functions as below:
• Aggregate feeding –Aggregates and sand have to be fed into the
individual feeder bins.
• Powder feeding –Powder here refers to cement, fly ash and
additives. These are important components for binding of material.
• Water –Water will help cement bind evenly with aggregates.
Specific quantity of water is must for any ready mix.
• Storage and conveyance –Storage and conveyance here refer
to storage of cement, fly ash, etc. They have to hold up quantity in
bulk and transfer small quantity by screw conveyor to the weighing
hoppers.
• Control system –Control system is very critical for any advanced
machine. It makes operation fast and accurate.
29

30. Batching Plant Operations
30

31. Batch Plant Components
Aggregate Batcher (Scale)
•Discharge Gates
Aggregate batcher discharge gate(s) are operated by a pneumatic
cylinder. Flow controls are installed on the solenoid valve or
cylinder that regulates the air flow to the cylinder. During normal
operation of the plant the batch control will control the operation
of the gates and the discharge rates.
•Discharge-Feed Interlock
The air cylinders are equipped with a reed switch. If the batch
control does not see a closed signal from the reed switch it will not
allow material to be fed into the scale.
31

32. Aggregate Batcher (Scale)
Vibrators
Aggregatebatchersareequipped
withapneumaticvibrator.The
vibratorfortheaggregate
batchershouldbesetupinthe
batchcontroltocomeontohelp
cleanoutthebatcherattheend
ofeachbatch.Thevibratorcan
alsobesetupinmostbatch
controlstoactivateiftheflowof
materialdropsbelowacertain
rateorstops.
32

33. Aggregate Batcher (Live Bottom)
Plantsequippedwitha“Live
Bottom”(Lo-ProStyle)
batcherinplaceofgatesuse
aconveyorbelttodischarge
thematerialinsteadofgates.
Duringdischargeofthe
batcherthebatcherconveyor
willdischargethematerialon
tothemixercharging
conveyor.Thespeedofthe
conveyoriscontrolledbythe
batchcontrolusingthefaster
andslowerfunction.
33

34. Mixer Charging (Incline) Conveyor
The incline conveyor carries the aggregate from the aggregate
batcher to the truck. It is interlocked with the aggregate
batcher discharge gate or batcher conveyor so the incline
conveyor has to be running before discharge of the aggregate
batcher can begin.
Aggregate Feed Gates
The aggregate feed gates are used to discharge material from
the aggregate storage bins into the aggregate batcher. The
valves that operate these gates are single acting valves which
require a momentary button in the batch control. When the
valve receives a signal from the batch control the gate will
open, when the signal is removed the gate will close.
34

35. Cement Batchers (Scale)
The cement batchers operate in a similar mechanism of
Aggregate Batchers.
Cement Batchers-Lo Pro
Plants equipped with a “Blending Cement Batcher” (Lo-Pro Style)
have a cement batcher that uses a screw conveyor to convey the
material and discharge it. A maintain signal is required from the
batch control to operate the batcher screw.
35

36. Cement Feed Gates
Cement feed gates are used to discharge material from the
cement silo. The gates are equipped with air cylinders that are
operated by pneumatic valves. The valves that operate these
gates are single acting valves which require a momentary button
in the batch control. When the valve receives a signal from the
batch control the gate will open, when the signal is removed the
gate will close.
Cement Feeder Screw
Screw conveyors may be used on some plants to convey material
from a silo to a weigh batcher. A momentary signal will be
needed to operate a screw that is feeding material to a batcher.
36

37. CementAirConveyors
AirConveyorsmaybeusedon
someplantstoconveyormaterial
fromasilotoaweighbatcher.
CementSiloAeration
Aerationofcementitiousmaterial
incementsilosorbinsis
necessarytogetthematerialto
flowandflowataconsistentrate.
Thisisaccomplishedthroughthe
useofaringcompressor(low
pressureblower)whichgenerates
highvolumeofairatalow
pressure.
37

38. Cement Silo Level Indicators:
A cement silo is typically purchased with level indicators
installed in them. Generally high and low indicators are used
in the silos.
•Low Indicator
The low indicator is positioned in the silo so that if the low
light is on another load (approximately 25 tons) can be
placed in the silo.
•High Indicator
High indicators are positioned in the silo to give the operator
the indication that it is full; once a high signal is attained all
fill activities should stop. The failure to stop filling the silo
once the high level has been reached could result in damage
to the silo and/or silo filter vents.
38

39. Cément Silo Filtre Vents
Silos that are not vented back to a central dust collector will
have a filter vent mounted on top of the silo. The cleaning
operation of the filter vent is controlled by a pulse
board that operates the pulse jet valves.
Water Meters
Badger Turbo water meter (turbine type) is used to meter
water. The meter will produce an output of one pulse for every
gallon of water that passes through the meter.
39

40. Water Batcher (Scale)
Water batchers are equipped with a butterfly valve located
in the bottom of the batcher to discharge the water.
Since rating of water during discharge is not common the
valve will open completely during discharge.
Water Holding Tanks
Water holding tanks are used to pre-meter a batch of water in
advanced of the batch being discharged. Instead of discharging
the batch water directly into the truck the water is metered
into a holding tank in advance.
40

41. Water Surge Tanks
A surge tank is located above a water batcher to allow for fast
weigh up of water. Surge tanks are equipped with a butterfly
valve located in the bottom of the tank to discharge the water.
Water Feed Valve
These feed valves are used to feed holding tanks and surge tanks.
Water Pumps
When a water pump is used to feed water to a plant, the pump is
usually setup to turn on when the water feed is activated. When
this is the case no extra controls are needed from the batch
control to run the water pump.
Source: CON-E-CO: Concrete Batch Plants & Equipment Company
41

42. Pneumatic Systems
•Air Compressor
the compressor will be setup to be on
whenever plant power is turned on.
When the plant power is turned on
the compressor will be controlled by
the pressure switch.
•Air Dryer
If a plant is equipped with an air dryer
it is intended to remove moisture from
the compressed air for either the plant
compressed air and/or the central
dust collector. The dryer will be
installed to be on whenever plant
power is turned on
42

43. •Plant Compressed Air Lock Out
The compressed air system on the batch plant will be
equipped with a lockout valve between the air compressor
and pneumatic components. The lock valve can be used to
dump the air past this point and be locked out to prevent
energizing of pneumatic components.
•Filters, Regulators and Lubricators
High pressure air regulators are installed on all plants to
regulate the air down to a working pressure. The air
compressor will build pressure in excess of 150 PSI but the
working pressure of the plant components is much lower
than this. A regulator will be found just past the air
compressor that is used to set the plant air pressure, usually
set to100 psi.
43

44. •Solenoid Valves
Generally two different types of solenoid valves are installed
on the batch plant, single acting solenoid valves and double
acting (inching) solenoid valves.
•Single acting valves
valve will have one coil when power is applied to the valve
the component will open when power is removed it will
close.
•Double acting (inching) valves
valve will have two coils, when power is applied to one coil
the component will move in one direction as long as power is
applied.
When power is removed the component will stop, the
component will not move again until power is applied to that
coil or power is applied to the other coil to move it in the
opposite direction.
44

45. ElectricalSystem
Electricalpowerentersthe
batchplantthroughaMain
Disconnectthatisusedto
supplypowertotheService
Panels.Themaindisconnect
providesthreephasepowerto
individualbreakersintheplant
servicepanelthatpower
motors.Eachmotorwillhavea
breakerandamotorstarter
thatswitchesthethreephase
powertoenergizethemotor.
45

46. PlantDischarge
Howmaterialsaredischargedoutoftheplantandintoa
mixertruckonadrybatchplanthasalottodowithhowthe
concretecomesoutofthemixertrucktotheenduser.The
sequenceinwhichmaterialsaredischargedmayvaryfrom
producertoproducer.Alotoffactorsgointodetermining
howmaterialsshouldbedischargedtoachieveaquality
product;slumptryingtobeachieved,materialsbeingused,
admixesbeingusedandetc.Asageneralstartingguidelinea
basic
dischargesequenceistodischargesomeofthebatchwater
(65-90%)intothemixertruckpriortoanyothermaterials,
thiswouldbecalled“HeadWater”.Oncethe“HeadWater”is
inthetruck10-20%ofaggregateshouldbeplacedintothe
mixertruckpriortothecementstarting.
46

47. Plant Discharge Cont...
Once10-20%oftheaggregateisinthemixertruckcement
canbedischargedintothemixertruck,whiletheaggregate
isbeingdischarged.Itisimportantwhendischarging
cementthattheflowratestaysconstantandthattheflow
ofcementisnottooslowortherearenotblastsofcement
powderbeingdischarged.
Thecementshouldfinishdischargingwithapproximately5-
15%ofaggregatelefttogointhemixertruck.Once
aggregatehasfinisheddischargingtheremainingbatch
water“TailWater”10-35%oftotalwatershouldbe
dischargedintothetruck.
47

48. Aggregate Material Handling Systems
PivotDistributors(Turnheads)
Pivotdistributorsorturnheadsareusuallycontrolledbyan
electricalcircuitthatwhenamomentarysignalissentto
energizetheelectricalcircuittheturnheadmovesuntilit
reachesthenextbinorpositionandstops.
Turnheadsareequippedwithastartwarninghornthat
notifiespersonnelintheareathattheturnheadwillbe
moving.Eachbintheturnheadisfeedingwillhaveitsown
proxyswitch.Theproxyswitchcanbefoundundertheturn
headchute,theyareusedtosensethepositionoftheturn
head.
48

49. RadialStacker
Forradialstackingconveyorsatransversingdriveisusedto
movetheconveyorfrombintobin,areversingstarterisused
toallowtheconveyortotravelinbothdirections.
Amomentarysignalisrequiredforeachheleftandright
traveldirectionsregardlessofwhetherthesignalcomesfrom
remotecontrolormanualpushbutton.
PlantChargingConveyor
Plantchargingconveyorscarrytheaggregatefromthe
charginghopperorotherconveyorstothestoragebin.When
thestartbuttonismomentarilypressedaholdingcircuit
throughthemotorstarteroraholdingrelaylatchesinand
keepsthemotorstarterpulledin,itwillstaypulledinuntil
thestopbuttonispressedandtheholdingcircuitisbroken.
49

50. HighCapacityDustCollectors
comeintwodifferentbasic
arrangements:
•Theyareeithermixer
loadingpointdustcollector
wheretheyjustcollectdustatthe
loadingpoint.
•Ortheyarecentraldust
collectorsweretheycollectdust
atthemixerloadingpointand
fromsilosandbins.
Mixer & Central Dust Collectors
50

51. Central Mix Plant Material Discharge
and Sequencing
Whenoperatingacentralmixplantthesequenceofhowthe
materialsareintroducedintothecentralmixergreatlyaffects
thequalityofproductoutofitandthetimeittakestoachieve
agoodmix.
Bestresultsareachievedwhenintroducingthewaterinto
thedrumfirst,followedbytheaggregateenteringonetotwo
secondslaterandthecemententeringonetotwoseconds
aftertheaggregate.Withabatchcontrolthereisnoindication
onwhentheindividualmaterialsenterorfinishdischarging
intothedrumsotheoperatorwillphysicallyhavetolookat
whenthematerialsareenteringandtheirlengthofdischarge.
Afterthematerialsstartenteringthedrumtheyshould
continuedischargingtogether.
51

52. The Factors to Consider when Choosing a
Satisfying Concrete Plant
•Whatkindofmixingmachineissuitabledependsonthe
performancemarksoftheconstructionofconcrete.For
example,inthewaterconservancyprojects,theforced
mixingmachinemustbeselected.What’smore,
accordingtothetypesofconcretematerialswhichwill
bestirred,appropriatestationsandsilosareavailableto
choose.
•Constructiongroundandobjectsmustbefully
consideredbeforeyoupayforyourconcreteequipment
tomakesurethatyourconstructionprojectcangoon
underthefavorableandsmoothcircumstances.
52

53. The Factors to Consider when Choosing a
Satisfying Concrete Plant
•Generallyspeaking,thestructureofsmallsizemixing
stationismuchsimplerthanthebigsize,anditiseasy
tooperate.Inthemeantime,theemployee’scharacters
areanimportantfactortooperatethemachine.Large
scaleconcreteplantoftenownshighautomation
degree,sotheskilledworkersarenecessary.Compared
withthelargescaleplant,smallsizeconcreteplant,
however,haslowerautomaticdegree.
53

54. References
54
I.Camlewaymachinery manufacture Co.,Ltd
II.CON-E-CO: Concrete Batch Plants & Equipment Company
III.Concrete Batch Plant Modeling Guide. IowaDNR.gov
IV.vincehagan.com
V.theconstructor.org
VI.Ukessays.com
VII.AimixGroup Co.,Ltd
VIII.alibaba.com
IX.buykorea.org
X.Apollo InfratechPvt. Ltd

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