Craft on How to realize the multi-point unloading and warehousing of bulk grain silos? Prepared by： www.immy.cn

Bulk grain silos are one of the mainstream choices for large-scale grain storage, which has high transfer efficiency, fast entry and exit and high degree of automation. The horizontal conveying of bulk grain mainly includes scraper conveyor, air cushion conveyor, single idler belt conveyor, and three-idler belt conveyor

(see: bulk grain horizontal conveying equipment).

In addition, there is also pneumatic pipeline type conveying mode, which is better than mechanical conveying, natural airtightness, light structure, greatly simplifies the warehousing process, but the deficiency lies in the limitation of conveying capacity, high energy consumption, and the defect of noise, which restricts its application in large-volume conveying engineering. The selection of equipment and process forms for the entry and exit of bulk grain silos is also based on the characteristics of the above-mentioned equipment, and scientific and reasonable selection is carried out. Silos are generally set up in groups, so the silo top should have the basic requirements of multi-point unloading.

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1. The buried scraper conveyor scraper conveyor can realize multi-point unloading in the middle (discharge gate and chute are set at the top of each silo) and flexible distribution; the equipment has good airtightness, good operating environment, small size, light weight, narrow conveying trestle, small output, and less investment.? ?

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However, when the scraper conveyor is discharged in the middle, the material may not be clean, and the return device needs to be set up in the machine head; the power of the equipment is larger, the energy consumption is large, and it is not suitable for long-distance transportation; the scraper, the chain and the bottom plate of the machine groove are worn out greatly, and they need to be maintained and replaced regularly; the grain is broken greatly, and it is not suitable for the storage and transportation of easily broken grain varieties; the failure rate of the scraper conveyor is high.

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1. Air cushion conveyor Air cushion belt conveyor has the characteristics of stable operation, large conveying capacity, small running resistance, small driving power, full ability to meet the requirements of self-enclosure, good operating environment, mature technology, reliable performance, low failure rate and low maintenance cost.? ?

However, the air cushion belt conveyor needs to realize the entry of multiple shallow round silos arranged through lap (only the head can be discharged), and there are the number of motors, There are many control points, and the head of each belt conveyor needs to be provided with a maintenance platform, the maintenance is inconvenient, the investment is slightly higher, and the overlap causes the grain to be thrown and broken for many times; the conveyor of the whole row of silos needs to be opened at the same time when the end bin enters the warehouse, and the energy consumption is slightly higher; the equipment is under positive pressure, and the sealing is not tight, and it is easy to lead to the dust escape of the conveying process; the climbing angle limit of the air cushion belt conveyor is insufficient, and the lap mode is not suitable for the shallow round silo group with too small spacing.? ?

1. Single idler belt conveyor and triple idler belt conveyor are both conventional belt conveying methods, the principle is similar, the difference is that the layout form and quantity of the bearing roller are different, and the sealing effect of the former is better.

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There are several ways to achieve multi-point unloading in the two:? ?

3.1 PLOUGH DISCHARGER (generally double-sided) Plough type multi-point unloading by controlling the lifting of the coulter and the bottom platform of the belt, so that the coulter and the belt produce friction, to achieve the purpose of material distribution and unloading, is a belt conveyor with the top of the bin more commonly used at present.

SINGLE IDLER CONVEYOR PLOW DISCHARGER

Fully Enclosed Three-Roller Belt Conveyor Plow Discharger Into The Warehouse

Compared with the lap joint, only one discharge belt conveyor needs to be arranged on the top of each row of silos; under the same working conditions, the comprehensive energy consumption is low, the maintenance cost is low; because there is no lap joint, the steel structure, electrical, etc. have greatly saved the investment, and the comprehensive investment is saved.??

But the shortcomings of the plough discharger are also more obvious: the material is easy to jam between the coulter and the belt, resulting in the material crushing or the unloading is not clean string silos;

the coulter and the belt are in contact for a long time, the coulter retaining strip and the belt are seriously worn, and the service life is low;

the material can not be switched smoothly, each time the discharging point is switched, the feeding needs to be stopped first, and the material conveying of the whole operation line is completed, the unloading point is switched in the no-load state, and then the feeding is started, and the operation efficiency is low;

because the lifting of the coulter and the lifting of the bottom platform are controlled by the motor, there are many fault points.

Unloading trolley warehousing (non-operation scenario)

3.2 The unloading trolley has a walking track and a driving mechanism, which can realize the unloading of any point in the horizontal section, and can be designed into a tee (middle and both sides, but can not be discharged at the same time in the middle and both sides), two tees (on both sides or in the middle and on one side), and single-sided discharge;

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The disadvantages of the mobile unloading trolley are: it occupies a large space, the existence of a concave arc suspension section, the height length increases, and the investment increases; the equipment cannot be sealed, and the environmental dust is difficult to control during work; in order to prevent wind and rain, a canopy should be added to the top of the silo, and the cost increases.

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3.3 The structure of the multi-point discharge single idler of the throwing type is simple, and it is easier to use the throwing type multi-point discharge than the three idlers. There are several ways to throw material:

(1) The dump type multi-point unloading and unloading point adopts a fixed throwback type trolley unloading, and each unloading point is equipped with 2 electric or starting valve plates, and the position of the raft plate is switched to realize the unloading in different directions.

Pitch-pitch parabolic multi-point discharge belt conveyor

(2) A hydraulic lifting mechanism is installed below the pitching and throwing multi-point discharge section to adjust the lifting height to meet the transportation and throwing and unloading needs of different materials. When the material passes through the discharge point when it is loaded, the lifting mechanism pushes the conveyor belt at the pitch discharge section to rise.

The material reaches the parabolic drum through the pitch discharge section, the throwing drum and the reversing drum form a parabolic unloading angle, and the baffle closes the material through the parabolic drum and throws people into the parabolic guide trough. When it is necessary to continue unloading at the rear discharge point, the front pitch discharge section can be restored to the original horizontal position.

When the head is discharged, all the pitch discharge section is restored to the original horizontal position, which is exactly the same as the normal conveying section, and the material smoothly arrives at the conveyor belt drive head blanking point.

Diagram of the working principle of Bühler's throw-off distributo

Throwing and unloading distributor is used in the shallow round warehouse of Qingbaijiang in Chengdu in grain storage

This multi-point discharge type can be combined with any belt conveyor, such as double air chamber, single air chamber air cushion machine, triple idler belt conveyor, double cone single idler belt conveyor, etc.

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(3) On the basis of the conventional single idler belt conveyor, the throwing and unloading distributor can be used to realize the multi-point unloading on one side, both sides or continuing to move forward on the top of the silo. The throwing and unloading distributor is mainly composed of a box, an electric push rod, a tee funnel and a reversing drum, and multi-point discharge is realized through the position switching of the tee hopper. When the tee funnel outlet is aligned with the discharge ports on both sides, it belongs to the two-sided discharge state, and when the three-way funnel is staggered with the discharge ports on both sides and flipped to another limit position, the material is thrown onto the conveyor belt to continue to move forward.? ?

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Compared with the buried scraper conveyor, it inherits the advantages of low crushing rate, low noise, small maintenance amount and low energy consumption of belt conveyor; compared with the process of lapping multiple belt conveyors, the secondary lifting height of the material at the transfer point is low, the material crushing rate is low, the amount of dust is small, and the number of motors and gate valves is reduced at the same time, and the cables and control points are also reduced, and the operation and maintenance are relatively simple. The main disadvantages of this method are: the valve plate should be closed tightly, otherwise it is easy to leak the material, resulting in a string of bins, and the requirements for smooth switching of the material are high. In addition, the conveyor belt needs to be wound many times, and the upper and lower adhesive layers are easy to crack, which requires high belt strength and large thickness, so that the quality is large, and the maintenance and replacement are too difficult.

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?PREPARED by:

WUXI HASEN IMPORT AND EXPORT CO.,LTD