What is a Scraper conveyor？

What is a Scraper conveyor？

Scraper conveyor is a continuous conveying equipment that relies on scraper chain circulation traction and chute carrying to transport bulk materials. It is the core supporting equipment of coal mine comprehensive mining face and is also widely used in the fields of mining, chemical industry, grain, organic fertilizer/environmentally friendly powder conveying.

Working principle of scraper conveyor

The motor drives the sprocket of the machine head to rotate through the hydraulic coupling and reducer, and drives the scraper chain to operate in an endless circular cycle; The materials are loaded into the central chute and continuously pushed by the scraper to the machine head for unloading; The empty chain returns to the tail of the machine along the bottom of the chute and feeds back and forth continuously.
It can be slightly horizontally and vertically bent to adapt to the concave convex bottom plate underground, and the fully mechanized mining machine can also be moved as a whole with the hydraulic support.

Core structure of scraper conveyor machine

The whole machine is divided into three main bodies and accessory parts:
1. Head section (power drive end)
Head frame, explosion-proof motor, hydraulic coupling, reducer, drive sprocket, unloading baffle; Heavy duty models have dual end drive for the nose and tail, enhancing long-distance power transmission.
2. Intermediate body (conveying body)
Central groove: made of wear-resistant steel plate, it is the core component that carries materials, supports the movement of the coal mining machine, and receives the thrust of the hydraulic support, making it the most susceptible to wear and tear;
Scraper chain: a combination of circular chain and scraper welding, used for pulling and pushing materials;
Transition groove and coal baffle: connect the machine head to prevent material from scattering.
3. Tail of the aircraft
Change the direction of the sprocket and tailstock, and rotate the direction of the scraper chain; Comes with a tightening device for tightening loose chains.
Accessory components
Hydraulic push jack, chain tensioner, anti slip anchoring device, sweeper, etc.

The mainstream classification method for scraper conveyors

1. Arrange according to the chain (most commonly used in coal mines)
Edge double chain: Two chains are distributed on both sides of the chute, with high load-bearing capacity, wear resistance, and heavy load and large conveying capacity scenarios;
Medium double chain: Two chains are arranged in the center, running smoothly and with low resistance. It is standard for mainstream comprehensive mining (SGZ series);
Single medium chain, triple chain: thin coal layer small machine, special for ultra heavy and large transportation capacity.
2. By usage scenario
Mining Flexible Scraper Conveyor (SGZ/SGB/SGD): the preferred choice for underground comprehensive mining, which can be bent and pushed;
Buried scraper conveyor: fully enclosed shell, conveying dust and powder (grain, organic fertilizer, ash), environmentally friendly dust suppression;
High temperature scraper machine: metallurgical and high-temperature slag conveying;
Light scraper: tunnel excavation, short distance transportation in small material yards.
3. According to the conveying inclination angle
The maximum upward movement is ≤ 35 °, and the downward movement is ≤ 25 °, with the best conveying efficiency on a flat working surface.

Core advantages and disadvantages of scraper conveyor

Advantages
The body is sturdy and impact resistant, and is not easily damaged by crushing debris or large materials;
Can bend horizontally and slightly up and down, suitable for uneven surfaces;
The fully mechanized mining machine can also serve as the walking track of the coal mining machine and the support point of the hydraulic support, integrating with the coal mining working face;
Can operate in both forward and reverse directions, making it easy to handle chain and bottom chain failures;
The fuselage is low and has strong adaptability to the thin coal layer space; Sealed conveying with buried scraper without dust leakage;
The length can be flexibly spliced to increase or decrease, and the material can be fed and unloaded at any point.
shortcoming
The no-load power consumption is high, accounting for about 30% of the total power, and the short distance economy is average;
The chains and chutes wear out quickly and require frequent maintenance;
Not suitable for long-distance transportation (conventional fully mechanized mining 150-300m, maximum 500m for ultra long working faces);
Easy to cause chain jumping, chain dropping, and material jamming faults.

Typical application scenarios of scraper conveyor

Coal mining industry (most important): coal transportation in fully mechanized mining face, transportation in channel roadway, and gangue discharge in excavation face;
Environmental protection/organic fertilizer industry: transportation of fermented and decomposed materials, powdered organic fertilizers, sludge, and dust removal ash;
Grain, chemical industry, power plant: closed transportation of grain particles, fly ash, and chemical powder materials;
Metallurgical building materials: short distance transportation of slag and clinker.