Dry building mixes plant (hereafter the plant) having a performance of 10 t/hr produces dry building mixes based on cement and gypsum cementing materials, whereas different mineral additives to stabilize the quality and give special properties to the mix are used.
The plant is designed for indoor use with air temperature from +5°C to +40°C.
Each dry building mixes plant is designed individually for Client’s facilities. To do that a structural designer is sent to the facility where the plant is going to be installed. There together with the Client he prepares a design assignment. After that within 20-30 days the Supplier develops a scheme design, agrees upon it with the Client and then sends a technical and commercial delivery offer for the plant, which serves as a basis for preparing a contract. After countersigning the contract the Client makes a 40-50% advance payment from the total price of the equipment. Average time of manufacture of the equipment is 120-150 days including development of the scheme design.
Design and operation
Technology of preparing products using a dry building mixes plant mainly involves thorough preparation of varisized dry graded sand. Therefore the major part of dry building mixes production is working with sand. The plant operation starts with charging moist (wet) sand into a charging bin by a grab crane or a front-side loader. Initial sand moisture should not exceed 4%. To improve sand flow a vibrator is installed on a bin wall. Sand layer thickness on a feeder belt is adjusted by a door in the bottom of the bin. By means of a feeder moist sand is conveyed to the elevator №1, which delivers it to the primary purification sieve. Vibrosieve does initial treatment of moist sand and screens large grains over 10 mm. Then the sand gets to the drum for drying. Drying drum consists of a rotating cylinder with paddles placed over the whole inner surface and a gas-fired burner which runs on gas and has all the necessary control equipment. There the sand is dried until it reaches moisture of 0,2-0,4%. The drying drum uses the counterflow principle – hot air moves towards the material. Having passed the drying drum the hot sand by means of the elevator №2 gets to a dry sand bin, where it cools down and stays until needed. After that the sand gets to a 4-grain-type vibrosieve by means of a belt feeder and the elevator №3. Sand over 3 mm gets from the vibrosieve to a waste bin. Small and medium-sized grains by means of natural flow, and big-sized grains by means of a screw conveyor get to 3-compartment service bins, where they are stored until needed. The mechanisms are controlled by operators from local control stations. Moist sand charging area (vibrator in a charging bin and a sand feeder) are controlled from the local control station №1. Sand drying area is controlled from the local control station №2 and includes drying drum control, smoke extractor control, elevators №1 and №2 control as well as control of a gas-fired burner of the drying drum. Local control station №3 controls equipment feeding dry sand to service bins, i.e. elevator №3, vibrosieve and a screw conveyor which feeds large-sized sand to a service bin.
Quality of sand drying process is controlled by a laboratory assistant who collects samples at a drying drum outlet. The laboratory assistant also carries out on-receipt quality control of incoming materials (checks if materials used in dry mix correspond to current GOSTs and other requirements) and concludes whether they are suitable for using.
Cementing agents – cement, gypsum, lime are charged by cement trucks or other pneumatic transport into silos of cementing agents storages, where they are stored until needed. The present dry mixes plant consists of only one cement service bin, but it can be upgraded as the production grows.
Moreover 3-compartment bins for mineral additives (powders) with total volume of 10m3 come with the plant. Additives are charged into bins by a crane from big-bags or other large packaging. Cut-off gates and screw feeders are installed under each compartment.
Dry mix components are batched by a multi-grade batch-type weighting batcher. Sand of necessary grade, mineral powders and other components are consecutively fed by 6 screw feeders to the multi-grade batcher. Switching screw feeders on and off after reaching necessary amount is automatic and defined by an operator from the main control station. Cement is charged the same way into a mixer, it is transported by screw feeder from a cement storage to a cement batcher, then discharged directly to the mixer.
Mixing time is defined by an operator in advance at the main control station and corresponds to the dry mix grade.
Mixer has two discharging cut-off valves. After mixing is over the ready batch is discharged to intermediate bins through one of the cut-off valves. A packaging unit is installed under one of the bins, a bogie for packing into big-bags or plastic buckets moves under the second bin. Authorization to open one of the cut-off valves comes from a packing person depending on where should the mix be fed to. Packaging unit allows packing mix into paper or PE valved bags having volume of 50, 25 or 10 kg.
Silos and bins of the dry building mixes plant are equipped with upper and lower level indicators, which send signals to corresponding control stations.
Description of main components
Bin SB-240-V.01.00.000
Charging bin is used for charging wet (moist) sand.
Technical characteristics:
Charged moist sand volume – 8 m3
Opening dimensions - 2600x3200 mm
Height from charging side – 1300 mm
Weight (incl. areaway guard rails) – 5636 kg
Moist sand elevator SB-240-V.02.00.000
Moist sand elevator is used for transporting materials from a belt feeder to moist sand primary purification vibrosieve in order to separate large-sized grains (over 10 mm).
Technical characteristics:
Elevator performance – 20 t/hr
Scoop volume – 2 L
Scoops spacing – 790 mm
Height of lift (at drums axes) - 6150 mm
Belt speed – 1.75 m/s
Motor-reducer type - МТС 52АD1780/5,5кW/4р (Czech Republic)
Moist sand purification vibrosieve
Performance – 10 t/hr
Sieve mesh – 10 mm
Vibrator wattage – 1.1 kW
Maintenance platform size and height - 3300 x2300 x3900 mm
Component weight – 3830 kg
Drying drum SB-240.10.00.000-01
Drying drum is used for drying sand up to moisture 0,2 ÷ 0,4%.
Technical characteristics:
Performance - 7..10 t/hr
Initial/final sand moisture - 4% / 0,2%
Drum inclination – 3 degrees
Size from inlet to outlet fitting – 7435 mm
Drum rotation drive motor – 4AM160S4У3
Electric motor power – 15 kW
Drum RPM - 5 min-1
Gas-fired burner type – suspended, modular with forced air feed and automatic control, with adjustable excess air coefficient, without predisplacement of an air-fuel mixture, two-stage GBG-034.
TU RB 00238473.017-97 (JSC Brestselmash RB)
Nominal heat power – 0.34 MW
Nominal gas pressure before cut-off valve - 4±1 kPa
Electric consumption of a burner – 0,6 kW
Drying drum dimensions
Length – 11000 mm
Width – 2810 mm
Height (without foundation) – 2410 mm
Component weight – 8410 kg
Dry sand elevator SB-240-V.03.00.000
Dry sand elevator transfers material from drying drum to a dry sand storage bin.
Technical characteristics
Elevator performance – 20 t/hr
Scoop volume – 2 L
Scoops spacing – 820 mm
Height of lift (at drums axes) - 6840 mm
Belt speed – 1.75 m/s
Motor-reducer type - МТС 52АD1780/5,5кW/4р (Czech Republic)
Output shaft rotation - 87 мин-1
Maintenance platform size and height - 2350 x1350 x5050 mm
Component weight – 1990 kg
Dry sand bin SB-240-V.04.00.000
Dry sand bin is a 14 m
3 all-welded cylindrical vessel. Dry sand from a drying drum is discharged into dry sand bin. There the sand cools down and stays until needed.
Technical characteristics
Bin volume – 14 m3
Feeding belt transporter
Belt width – 650 mm
Motor-reducer type (Czech Republic) - МТС 52АG1780/4кW/6р
Transporter belt speed - V=0,18 m/sec
Platform size and height (bin roof) - Ø3000x4685 mm
Component weight – 3500 kg
Vibrosieve elevator SB-240-V.05.00.000 and vibrosieve SB-240.12.00.000
Vibrosieve elevator consists of 1) frame, on which a 3-storey 4-grain-type vibrosieve, which screens dry sand, is installed 2) elevator №3 3) elevator drive maintenance platform
Technical characteristics
Elevator performance – 20 t/hr
Scoop volume – 2 L
Scoops spacing – 820 mm
Height of lift (at drums axes) - 6840 mm
Belt speed – 1.75 m/s
Motor-reducer type - МТС 52АD1780/5,5кW/4р (Czech Republic)
Vibrosieve
Performance – 10 t/hr
Charging feed size – 0… 10 mm
Number of grain types – 4 pcs
Cut point: I – up to 0,8 m; II – up to 1,4 mm; III – up to 3,2 mm; IV – over 3,2 mm.
Component weight –6060 kg
Sand service bins SB-240-V.06.00.00
3 sand grain types are charged to and stored in a block of sand bins.
Technical characteristics
Compartments – 3 pcs
Bins volume – 30 m3
Performance of 3 screw feeders – 20 t/hr
Motor-reducer type - AS56S114ML4 (Austria)
Power – 5.5 kW
Large-sized grains screw feeder
Performance – 20 t/hr
Motor-reducer type - ASA56S114ML4 (Austria)
Power – 5.5 kW
Component weight – 4070 kg
Mineral powder bins SB-240-V.07.00.000
3 types of mineral additives are charged to mineral powder bins (charging from big-bags by a crane), stored there and fed to a multi-grade batcher according to a dry mix formula.
Technical characteristics
Number and volume of compartments - 3x3,35 m3
Charging height – 2865 mm
Screw feeders performance – 15 t/hr
Motor-reducer type - AS56S114ML4 (Austria)
Power – 5.5 kW
Weight – 4471 kg
Multi-grade batcher SB-240-V.08.00.000 (discrete weighting batcher SB-241Б.02.00.000-07)
Multi-grade batcher is a bin standing on load cells, which are installed on a mounting frame.
Technical characteristics
Bin volume – 4 m3
Weighting limits – 270… 2500 kg
Load cells – 4 pcs
Weight – 2100 kg
Elevator for feeding materials to a mixer SB-240-V.09.00.000
Elevator for feeding materials from a multi-grade batcher to a mixer.
Technical characteristics
Elevator performance – 40 t/hr
Scoop volume – 2 L
Scoops spacing – 405 mm
Height of lift (at drums axes) - 7160 mm
Belt speed – 1.75 m/s
Motor-reducer type - МТС 52АD1780/5,5кW/4р (Czech Republic)
Component weight – 1782 kg
Cement silo SB-240-V.10.00.000
Cement silo has a volume of 28 t, it is installed on a supporting structure.
Technical characteristics
Silo volume – 28 t
Compressed air consumption – 1 m3/min
Screw feeder
Performance – 20 t/hr
Motor-reducer type - ASA 76S161M4 (Austria)
Power – 11 kW
Component weight – 3455 kg
Cement batcher SB-241А.01.41.000В
Cement batcher is used for automatic discrete weight batching of cement according to a dry mix formula.
Technical characteristics
Charging bin max. capacity – 650 kg
Weighting limits of cement – 90///550 kg
Load cells – 3 pcs
Weight – 210 kg
Gas purification block SB-240-V.11.00.000
Gas purification block is used for forced removal of combustion products and gases, produced as a result of a drying drum operation.
Technical characteristics
Number and diameter of cyclone separators – 2 pcs / Ø 1000 mm
Power of smoke extractor electric motors – 11 kW
Component weight – 4395 kg
Mixing block SB-240-V.12.00.000
Mixing block is used for mixing components, distributing and packing dry mix.
Technical characteristics
Mixer type – planetary-rotary SB-242-8М-03
Charges materials volume – 1500 L (1,5 m
3)
Rotor rotation speed – 10.6 min
-1Two planetary rotors rotation speed – 38.8 min
-1Electric motors installed power – 2х18,5 kW
Discharging cut-off valves – 2 pcs, with an angle of 180 degrees
Pneumatic cylinders type - 40М2L200AO 500 “Camozzi”
Working pressure in a pneumatic system - 0,6 МPa
Type and number of packaging batchers - DC-50 / 1 pc
Batcher performance – 8…12 t/hr
(charging into valve bags)
Batching limits – 10…50 kg
Batching accuracy - ±1%
Installed power – 2,2 kW
control – from a stand-alone control station
Component weight – 8280 kg
Control block SB-240-V.13.00.000
Control block contains electrical equipment and control systems for automatic batching and dry mix manufacturing areas. Besides it contains equipment of an automatic control system and equipment of operator’s working station.
Technical characteristics
Dimensions
Length – 3200 mm
Width – 2700 mm
Height – 2800 mm
Weight – 2750 kg
Electrical equipment СБ-240-V.14.00.000
Electrical equipment consists of 1) three local control stations situated close to facilities to be controlled, automatic control system (ACS) which is situated in the control block and controls feeding, batching, feeding to a mixer and production of a ready dry building mix 2) power equipment cabinet and control equipment cabinet.
Pneumatic equipment СБ-240-V.15.00.000
Pneumatic equipment elements are installed at units and blocks of the dry mix plant. Pneumatic equipment provides mechanisms with air pressure in the pneumatic system of not less than 0,6 MPa and nominal air consumption up to 2 m3/min (compressor and receiver with a volume of about 5 m3 are not included).
Set of pneumatic equipment consists of:
- four cabinets for pneumatic equipment (Camozzi, Italy) where pneumatic dispensers, controlling operation of pneumatic cylinders, pneumatic drives and pneumatic vibrators are installed. Pneumatic cabinets are also equipped with pressure-regulating filters, oil atomizers, flow-regulating valves, safety valve and manometers.
- a unit consisting of 3 receivers. Nonreturn valve, facets etc. are mounted on it.
- compressed air is fed to acting mechanisms via steel pipes and rubberized fabric hoses.
- pneumatic dispensers are controlled from a control station.