Calculation of a screw conveyor
| Bulk mass in a loose state, t/m³ | Angle of repose | |
| Gypsum | 0,8–0,9 | 40 |
|---|---|---|
| Lime | 0,5–0,7 | 43 |
| Limestone screening | 0,9–1,2 | - |
| Ash | 0,6–0,8 | 40–45 |
| Mineral powder | 0,95–1,2 | - |
| Chalk | 0,95–1,2 | 45 |
| Cement | 0,8–1,2 | 40-50 |
| Sand | 1,5–1,7 | 0-50 |
| Dry building mix | - | 40-50 |
| Other material | - | - |
General Information on VK and VKPO screw conveyors
A. Geometric dimensions
TECHPRIBOR plant develops, manufactures and sells general-purpose screw conveyors of VK-160M and VK-273 M, VK-102, VKPO-273 models designed for transportation of small-sized, granular, dust-like, explosion-proof, non-aggressive materials of various origin. Stainless steel screw conveyors VK and VKPO are designed for transportation of small-sized, granular, dust-like, chemically aggressive and food materials. Screw conveyors of these models have three main standard sizes of feeding screws (auger): auger diameter – 88 mm, pitch – 80 mm (Fig. 4), auger diameter – 123 mm, pitch – 140 mm (Fig. 5), auger diameter – 224 mm, pitch – 230 mm (Fig. 6).
Screw conveyor VK-102 (Maximum length (L) – 4 m)
dscrew = 88 mm, hscrew = 80
Fig. 4
Information for designing organizations: General view of VK-102 screw conveyor in AutoCAD2002 format
Screw conveyor VK-160M (Maximum length (L) of VK-160M conveyor – 5 m)
dscrew = 134 mm, hscrew = 135
Fig. 5
Information for designing organizations: General view of VK-160 screw conveyor in AutoCAD2002 format
Screw conveyor VK-273M type (Maximum length (L) of VK-273M conveyor – 6 m, VKPO-273 – 12 m)
dscrew = 224 mm, hscrew = 223
Fig. 6
Information for designing organizations: General view of VK-273 screw conveyor in AutoCAD2002 format
B. Drive station
The screw conveyors manufactured in TECHPRIBOR plant are equipped with high-torque gear-motors (international manufacturer) that ensure the long-term operation of the drive station – (8-24) hours a day when operating in S 1 operation mode (GOST 183-74).
| Parameter name | «VK-102» | «VK-160VM» | «VK-273M» | «VKPO-273» | ||||
|---|---|---|---|---|---|---|---|---|
| Gear-motor type | XC-63 | XC-75 | XC-110 | XC-110 | ||||
| Rated rotation speed, rpm | 93 | 187 | 93 | 187 | 93 | 187 | 93 | 187 |
| Rated torque, Nm, max | 94 | 50 | 263 | 137 | 469 | 247 | 469 | 247 |
| Electric motor power, kW, max | 1,1 | 3 | 5.5 | 5.5 | ||||
| Weight of drive station, kg | 47.7 | 52.5 | 112.2 | 127.2 | ||||
C. Capacity
The capacity of a screw conveyor is determined by geometric dimensions of the feed screw (auger), its rotation speed, degree of filling, internal friction ratio of the material and inclination angle of the housing. To select the capacity of VK and VKPO screw conveyors, please use Table No. 2.
| * для материалов с внутренним коэффициентом трения 0,65 (цемент) | ||||||||
| Screw conveyor capacity, m3/h* | ||||||||
|---|---|---|---|---|---|---|---|---|
| Model of screw conveyor | «VK-102» | «VK-160VM» | «VK-273M» | «VKPO-273» | ||||
| Rated rotation speed, rpm | 93 | 187 | 93 | 187 | 93 | 187 | 93 | 187 |
| α,° = 0 | 0.8 | 1.6 | 2.8 | 5.7 | 20.7 | 41.6 | 20.7 | 41.6 |
| α,° = 5 | 0.7 | 1.4 | 2.5 | 5.1 | 18.6 | 37.4 | 18.6 | 37.4 |
| α,° = 10 | 0.6 | 1.2 | 2.2 | 4.5 | 16.5 | 33.2 | 16.5 | 33.2 |
| α,° = 20 | 0.5 | 1 | 1.8 | 3.7 | 13.4 | 27 | 13.4 | 27 |
Fig. 7
D. Available nozzles configurations
The configuration of the unloading and loading nozzles, VK and VKPO screw conveyors, can be a standard design (Fig. 8,9,10) and can be changed by customer specifications. The loading and unloading nozzles are equipped with connecting flanges for interfacing the screw conveyor with other units of production equipment (bulk material storage bins, mixers, batchers, shut-off and control valves, etc.).
Standard versions of connecting flanges
1. Nozzle of VK-102 screw conveyor (Fig. 8). In standard version, the unloading or loading nozzles can be connected to peripheral process equipment by means of corrugated flexible inserts (flexible industrial sleeves (PVC) with a diameter up to 100 mm).
2. Housing flange for VK-160M and VKPO-160 screw conveyors (Fig. 9). Option of attaching a soft insert D-160.
3. Housing flange for VK-273M and VKPO-273 screw conveyors (Fig. 10). Option of attaching a disk shutter of DZ-260.270 P and DZ-260.270.DNT 63.125 models.
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 |
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| Fig. 8 | Fig. 9 | Fig. 10 |
F. Additional options
The screw conveyors manufactured in TECHPRIBOR plant can be equipped with start-up electrical equipment, controllers and time relays at request of the customer, which allows the use of VK and VKPO screw conveyors for volumetric dosing of bulk materials.
Е. Weight of assemblies
To determine the total weight of VK and VKPO screw conveyors, please use Table No. 3, which lists the weight of separate assemblies.
To determine the total weight of the screw conveyor of VK model, it is necessary to summarize the weight of drive station, supporting platform and required number of linear meters of the housing and the auger. To determine the total weight of the screw conveyor of VKPO model, it is necessary to summarize the weight of drive station, supporting platform and required number of linear meters of the housing and the auger.
Table No. 3. Weights of VK and VKPO screw conveyors
| Model of screw conveyor | «VK-102» | «VK-160VM» | «VK-273M» | «VKPO-273» |
|---|---|---|---|---|
| Drive station | 47.7 | 56 | 112.2 | 127.2 |
| Supporting assembly | 6.5 | 16 | 23 | 23 |
| Intermediate support (for VKPO model) | - | - | - | 12.5 |
| Linear meters of screw conveyor length | 16 | 23 | 51 | 55 |
Fig. 12
G. Cost calculation (1)
To determine the cost of screw conveyors of VK models, it is necessary to summarize the costs of drive station, support assembly and required number of linear meters of the screw conveyor (Fig. 12). To determine the cost of screw conveyors of VKPO models, it is also necessary to add the cost of an intermediate support. Prices for these items see at the upper part of page in the section “Cost of modifications”. For easy use, the cost of the drive station and the support assembly is shown in one line.
Example:
- The cost of VK-102 conveyor 3 meters long in standard configuration (stand-alone bearing supports, imported gear-motor, inspection hatch) – 65,300 rubles including VAT.
- The cost of VK-160 conveyor 3 meters long in standard configuration (stand-alone bearing supports, imported gear-motor, inspection hatch) – 101 600 rubles including VAT.
- The cost of VK-273 conveyor 3 meters long in standard configuration (stand-alone bearing supports, imported gear-motor, inspection hatch) – 140 800 rubles with VAT.
H. Example designation
Screw conveyors of VK and VKPO models manufactured in TECHPRIBOR have the following designations:
Screw conveyors of VK and VKPO stainless steel models manufactured in TECHPRIBOR have the following designations:
I. Advice and technical support
In order to find out whether the selected equipment is available in the finished products warehouse or to clarify their manufacturing time, please contact our consultants. For more detailed information on the technical characteristics of VK and VKPO screw conveyors, as well as for ordering non-standard products, please contact our technical specialists by the phones: 8 (48751) 90-59-5, (48751) 90-59-6, 8(903) 658- 62-41, 8(905) 626-79-10.
Quality which built confidence of professionals!
Screw conveyors of series «VK» and «VKPO», «HARD SCREW». Maintenance documentation. User manual. Passport.
General Information
The screw conveyors of VK and VKPO models are designed for horizontal and inclined transportation of dusty granular and small-sized materials. These screw conveyors can be used at enterprises of various industries as feeders, mixers and volumetric batchers. The simplicity of design, high performance, reliability and modesty of screw conveyors of these models determine their widespread use in process operations associated with transportation of large volumes of bulk materials.
A screw conveyor consists of the following components and parts: a housing (1), a feed screw (auger) (2), bearing supports (3), loading and unloading pipes (4) of mounting flanges (5), a gearbox (6) and a drive motor ( 7) (Fig. 1). When the feeding screw rotates, the transported material moves from the loading to the unloading window.
Composition of the screw conveyor
Fig. 1
Depending on location of the screw conveyor within arrangement of production lines, the drive of the feeding screw can be implemented both as a pushing (TL) and a pulling configuration (TN). (Fig. 2)
Configurations for location of the feeding screw drive
Fig. 2
When implementing the pushing configuration, the feeding screw drive is located on the loading window side. When a pulling configuration, the feeding screw drive is located on the unloading window side. The mentioned installation configurations of the feeding screw drive do not affect performance of the screw conveyor and are assigned accordingly to conditions for providing access to the drive for its maintenance.
Depending on the type of material being transported, the screw conveyor can be equipped with solid screw or ribbon-flight screws. Therefore, for transportation of well-flowing materials such as cement, dry sand, gypsum, chalk, slag, powder lime, a solid feeding screw (C) is used. For supply of lumpy materials such as gravel, limestone, granular slag, it is advisable to use a ribbon flight screw (L). (Fig. 3)
Types of screws for screw conveyors
Fig. 3
Number of supports for feeding screw
Depending on the length, screw conveyors can be equipped both with a pair of bearing blocks located in the end caps and with additional supports mounted inside the housing. The screw conveyors of VK model are produced without an intermediate support; therefore the maximum length of the feeding screw is 4 meters for VK-102, 5 meters for VK-160 and 6 meters for VK-273. Intermediate bearing supports, which are supplied in VKPO screw conveyors package, allow for increasing the material supply range up to 10 meters for VKPO-160 and 12 meters for VKPO-273.
Advantages
When creating the screw conveyors of VK and VKPO models, the design department of TECHPRIBOR plant used a number of unique technical solutions aimed at improving operational properties of the equipment, increasing its reliability and durability. A short list of the main competitive advantages of the screw conveyors of these models approves the above.
Stand-alone bearing supports – the key advantage of reliable operation without breakdowns and downtime
It is no secret that some manufacturers of screw conveyors, in pursuit of imaginary manufacturability and not significant savings in production costs, use the units where bearings and sealing elements are in a single housing. Such achieved reduction in weight, dimensions, and sometimes in costs of the bearing assembly, in practice results in frequent repairs and long downtime. Support assemblies, the design of which does not provide for a possibility of visual monitoring of sealing elements condition, in the real production environment are simply doomed to periodic breakdowns caused by the ingress of transported material into the bearings.
The specialists of TECHPRIBOR, understanding that the time lost during emergency repairs, replacing bearings, sealing elements and waiting for delivery of replacement parts is the lost time in production process, applied the unique configuration of stand-alone bearing supports. In case when the tightness of a sealing element is disrupted for any reason, the transported material freely pours out of the housing, and does not fall into the bearings. Increased dusting or material accumulation during operation of the auger can be easily detected even with a surface inspection of the equipment, and timely replacement of the sealing element will avoid serious damage. Thus, a fairly simple technical solution that makes it possible to visually check the seal condition reduces equipment downtime, saving both money and manpower.
Increased diameter of screw axis for maximum torque transmission
The screw conveyors used to transport bulk materials of high density are usually equipped with high-torque gear-motors. However, for a confident start and high reliability, it is necessary for the feeding screw itself to have sufficient strength, otherwise the high torque provided by the drive station will either not be fully realized, or it will lead to a serious accident – breakage of the auger.
In order to increase the reliability of the equipment operation in the most difficult operating conditions, VK and VKPO screw conveyors are provided with screw axes of increased diameter, capable of transmitting maximum torque without a damage.
Increased wall thickness for long operation with abrasive materials
The inner surface of the housing, the feeding auger of the screw conveyor are subject to abrasion, the intensity of which directly depends on the physical and mechanical characteristics of the material being transported. Cement, powdered lime, ash, slag, mineral powder, as well as a number of other bulk materials that the screw conveyors transport are medium or highly abrasive. It is for this reason that the screw conveyors, designed to work in difficult conditions, should have an increased thickness of housing walls, and an illusory saving in this matter subsequently turns into costly repairs.
Easy connection of equipment
Unloading and loading nozzles of VK and VKPO screw conveyors have standardized geometry that allows implementing the most various configurations for integration into production equipment. Thanks to the thought-out design of the mating parts, the screw conveyors can have both rigid fixation of the nozzles, and a connection for usage of soft inserts. Installation of shut-off and control valves, soft inserts, flexible industrial sleeves (PVC) does not create any difficulties and can be carried out by one person without use of lifting devices. Such approach to the issues of connecting process equipment allows accurate installation of the screw conveyor, secure anchorage, ensured tightness of the connection, while saving time and manpower.
Awards and certificates
The screw conveyors of VK and VKPO models were awarded with the diploma “100 Best Goods of Russia” program in 2012.
The screw conveyors of VK and VKPO models comply with the requirements of Technical Regulation of Customs Union TR CU 010/2011 “On Safety of Machines and Equipment”.
