symon shorthead cone

Symons Shorthead Cone Crusher: An Overview

The Symons Shorthead cone crusher is a specific configuration of the renowned Symons cone crusher line, designed for finer crushing and the production of smaller product sizes. It is characterized by its steeper head angle and longer parallel zone in the crushing chamber compared to the Standard model. This design makes it particularly suited for secondary, tertiary, and quaternary crushing stages, where the feed material has already been reduced and the goal is to achieve a well-shaped, fine aggregate or sand product. This article outlines its key features, compares it with the Standard model, and examines its practical application in modern aggregate processing.

Key Features and Design Principles

The Shorthead's defining feature is its crushing chamber geometry. The steeper head and longer parallel zone create a finer setting capability and promote inter-particle comminution (rock-on-rock crushing) in the lower section of the chamber. This results in:

• Finer Product Size: Capable of producing smaller CSS (Closed Side Setting) and thus finer output.
• Improved Product Shape: The extended crushing action promotes more cubical product shape, which is critical for high-quality concrete aggregates.
• Higher Reduction Ratios: In its applicable range, it can achieve higher reduction ratios than the Standard model for a given feed size.

Comparison: Symons Shorthead vs. Standard Cone

The primary difference lies in their chamber design and typical application within a crushing circuit. The following table summarizes the key distinctions:

Feature	Symons Shorthead Cone	Symons Standard Cone
Chamber Shape	Steeper head angle, longer parallel zone.	Flatter head angle, shorter parallel zone.
Feed Opening	Smaller, accepts finer feed.	Larger, can accept coarser feed.
Typical Application	Secondary/Tertiary/Quaternary crushing for fines production.	Secondary crushing (can also be used as primary if sized appropriately).
Product Size	Finer output at smaller CSS settings.	Coarser output range compared to Shorthead.
Capacity (for same size crusher)	Generally lower when processing similar feed due to finer chamber.	Generally higher for coarser feeds.

Real-World Application Case Study: Aggregate Plant in Texas, USA

A large granite quarry operation in Texas was facing challenges with meeting strict specifications for concrete sand and chip seal aggregates. Their existing secondary crushers were producing excessive flaky material and insufficient yield in the 3/8" minus fractions.

Solution: A 7-foot Symons Shorthead cone crusher was installed in a tertiary position following two Standard 7-foot cones operating in secondary roles.
Implementation: The Shorthead was configured with a fine liner profile and set to a 1/4" (6mm) CSS.
Results:

• Product Quality: The cubicity of the 3/8" x #4 and #4 x #30 aggregates improved significantly, meeting DOT (Department of Transportation) specifications for chip seal.
• Sand Production: The yield of concrete sand (#30 x #200) increased by approximately 22%, reducing reliance on downstream screening waste.
• System Balance: By offloading the fine-crushing duty to the purpose-built Shorthead, the upstream Standard cones could be opened up slightly to optimize their throughput for mid-size aggregate production, increasing overall plant efficiency.

This case demonstrates how the specialized geometry of the Shorthead cone provides a targeted solution for quality fines production within a balanced circuit.

Frequently Asked Questions (FAQ)

1. Can a Symons Standard crusher be converted into a Shorthead?
   Yes, this is a common practice. Conversion involves replacing key components including the mantle, concave liners, main shaft (which has a different taper), and often the top shell or adjustment ring assembly depending on the specific frame design. It is not merely a liner change but a significant mechanical conversion that must be done according to manufacturer specifications.

2. What are typical feed size limitations for a Shorthead cone?
   A general rule of thumb is that the maximum feed size for a Shorthead should not exceed 2-3 times its CSS setting. For example, with a target CSS of 10mm, the feed should ideally be no larger than 20-30mm. Feeding excessively large material can lead to poor performance, packing, and potential damage.

3. Is the Symons Shorthead suitable for producing manufactured sand?
   Absolutely. Its ability to generate fines through inter-particle compression in the parallel zone makes it one of the traditional preferred choices for sand production in hard rock applications before the advent of dedicated vertical shaft impact (VSI) crushers. It often produces sand with excellent particle shape.

4. How does power draw compare between Standard and Shorthead configurations?
   For processing similar tonnages of the same feed material, a Shorthead may operate at a slightly higher power draw due to its finer setting and higher pressure required for inter-particle crushing in its longer chamber when producing finer product.

5.What are common wear parts unique to maintaining performance on these units?
Key wear parts beyond mantles and concaves include:

• The main shaft sleeve/distributor plate assembly which ensures even feed distribution around chamber
• Eccentric inner/outer bushings which control gyratory motion
• Bowl liner retaining hardware ("U-bolts" or wedge systems)
  Proper maintenance scheduling on these components directly impacts consistent product gradation