Types of Ship Loading Chute for Bulk Materials

The ship loading chute is an important feeding device for loading ships, typically installed at the boom end of a ship loader. The type of discharging chute used is primarily determined by factors such as the physical properties of the materials being loaded, ship dimensions, draft, dock water level variations, and environmental requirements.

Telescopic Chute of Ship Loader

Types of Ship Loading Chutes

Chutes can be classified in several ways:

By geometric shape: including guide plates, straight chutes, telescopic chutes, segmented chutes, spiral chutes, and more.
By construction materials: such as steel chutes, ceramic chutes, and fabric chutes.
By environmental requirements: such as dust-free chutes, water-spray or mist-dusting chutes, and negative-pressure dusting chutes.
By trimming requirements: including non-throwing chutes, fixed-angle throwing chutes, automatic throwing shovels, and forced-throwing machines.

Ship Loading Chutes with Different Geometric Shapes

1. Guide Plate Loading Chute

This type, also known as a non-physical chute, relies solely on guide plates to adjust the angle, projecting material from the ship loader boom into the hold of ships. Due to its free-throwing characteristic, operators may find it challenging to control the initial discharge point. It is suitable for small open barges or large vessels with wide hatches and is typically used for dense bulk materials, such as iron ore. Lacking any leveling or cushioning features, it exposes the material outside the ship's hold, making it less environmentally friendly. However, it has high loading efficiency, minimal maintenance, and eliminates concerns about chute clogging.

2. Straight Loading Chute

The straight chute, one of the most common types, is a fixed, single-section chute with a non-adjustable length. Widely used for loading bulk materials like ore, coal, cement, sand, grain, and fertilizer, it usually features a swinging mechanism to keep the chute vertical as the boom pivots, with a throwing shovel for trimming if needed. Its main drawback is the inability to adjust the chute length, requiring careful design to consider the chute's entry into the hold and its relative position to the vessel during movement.

3. Telescopic Loading Chute

This popular type of chute, suitable for most bulk materials, features adjustable length, making it ideal for large vessels that experience significant height changes between high-water empty loads and low-water full loads. The chute outlet can be positioned close to the bottom of the hold, effectively reducing dust escape. Typically, a winch drives the telescopic mechanism, and the inner sections have positioning rails for smooth extension and retraction. A throwing shovel can also be installed at the bottom for materials that require trimming.

4. Segmented Loading Chute

This type of chute consists of fold-able sections, typically driven by wire ropes to enable chute extension and retraction. The segmented angles reduce material impact, making it suitable for materials that require cushioning to minimize breakage. Compared to spiral chutes, segmented chutes offer a lower overall height, allowing easier clearance with transport vessels. However, they are unsuitable for materials with poor flow-ability.

5. Spiral Loading Chute

Spiral chutes are primarily used for loading bagged materials, such as grain, feed, and fertilizer. The spiral shape effectively reduces the material's descent speed, making it especially suitable for free-flowing materials that require protection from damage. Its drawback is that the chute length is fixed and non-adjustable, so design must carefully match chute length to operational requirements for loading, trimming, and ship clearance.

6. Cascade Loading Chute

This type uses a modular sleeve assembly, allowing the number of sleeves to be adjusted to match the actual loading height. Wire ropes control the sleeve's real-time extension, making it flexible and adaptable to varying chute lengths and water levels. However, its sealing is relatively poor, offering less effective dust control than enclosed chutes.

Ship Loading Chutes with Different Materials

1. Steel Loading Chute

Suitable for most bulk materials, steel chutes can be lined with wear-resistant materials to match the hardness and abrasiveness of the transported material. For instance, for ores, wear-resistant steel overlay plates may be used; for coal, wear-resistant steel or ceramic liners may be applied; and for grain, feed, or fertilizer, stainless steel or polymer materials may be used.

2. Ceramic Loading Chute

Typically made up of small ceramic cones connected by wire ropes, this type of chute is flexible and can be extended. A canvas cover can be added for environmental protection. The nested cones provide a segmented drop path, buffering the material as it descends, and can either follow a zigzag or straight-line design, with the latter being lighter and less prone to wear.

3. Fabric Clothe Loading Chute

Fabric chutes are usually used for low-abrasion materials such as feed, flour, and fertilizer. A rubber dust curtain at the bottom effectively prevents dust dispersion. Due to its flexible construction, the chute can adjust to the increasing pile height, typically with a height-sensing switch that retracts the chute as the pile rises.

Chutes with Different Dust Control Requirements

1. Non-Dusting Collector Chute

This chute has no dust control mechanism and relies on design features like dust skirts for dust suppression. Suitable for materials with relatively low dust, such as pellet feed or loose sugar, this chute features a skirt at the bottom that covers the pile to prevent dust escape.

2. Dusting Loading Chute with Water Spray or Mist-Type Wet System

Commonly used for water-tolerant bulk materials like ore or coal, this chute type employs water mist, water spray, or dry mist for dust suppression. The system includes a water supply, pressurization, and spraying mechanism, with options such as hose reel, tank, or hydrant water supply and spray nozzle or mist cannon for dust control.

3. Loading Chutes with Dust Collector

For bulk materials that cannot get wet, like grain, cement, or loose sugar, dry dusting options include centralized negative-pressure and single-point bag dust collection systems. Centralized systems require complex dust collection pipelines and are relatively energy-intensive. As environmental standards continue to rise, more projects are adopting dry dusting chutes.

Loading Chutes with Different Trimmer

Trimming requirements categorize chutes into non-throwing chutes, fixed-angle throwing chutes, automatic throwing shovels, and forced-throwing machines. Non-throwing chutes lack throwing heads, suitable for free-flowing materials that naturally pile well. For general bulk materials, spraying or throwing devices can be added to telescopic chutes to achieve a leveled pile.

1. Fixed-Angle Trimmer

This system, used for low-hardness, low-abrasion materials, has minimal maintenance but is prone to wear.

2. Adjustable Angle Trimmer

Widely used for ore, coal, fertilizer, and sulfur, this system adjusts the throwing angle for leveling, typically powered by hydraulic cylinders or electric push-rods.

3. Loading Chute With Throwing Machine

Used for materials with poor flow-ability, such as wood chips or loose sugar, spiral chutes often incorporate a throwing machine for material discharge.

Chutes can also be combined, such as telescopic chutes with throwing shovels and rotation mechanisms for precise control of material drop location and height. The choice of chute design considers material properties, dock hydrology, ship draft, and other operational conditions to ensure the optimal, reliable, and advanced configuration for ship loading operations.