LMC Gravity Separator for Seed & Grain Processing | Vistasort
Seed & Grain Processing Equipment

LMC Gravity
Separator

The LMC Marc Series gravity separator delivers total, exact, distinct density-based separation for seed and grain — removing damaged kernels, light material, and foreign matter that screening alone cannot address. Trusted since 1941. Available through Vistasort across Canada.

Since 1941
LMC's Proven Design
3 Models
300 · 400 · 500 Series
620 ft³/hr
Max Capacity (Model 500)
Any Crop
Pulses, Cereals, Oilseeds & More

What Is a Gravity Separator?

A gravity separator is a precision cleaning machine that separates seed and grain by density — using a combination of airflow, deck vibration, and controlled incline to stratify product into distinct layers by weight. Unlike screens that separate by size, or color sorters that separate by visual characteristics, gravity separators target the one thing other machines can't address: density differences between good product and contaminants of the same size.

The LMC Marc Series Gravity Separator is widely recognized as one of the most reliable and precise gravity separators in the seed conditioning and grain processing industry. Originally engineered by LMC in 1941 and continually refined to meet modern processing demands, the Marc Series combines proven design with dependable, repeatable performance across virtually any dry, flowable crop.

  • Removes low-density material that screens and air systems cannot separate
  • Separates damaged kernels, light seed, weed seed, and foreign material
  • Delivers consistent, repeatable results with minimal operator adjustment
  • Works with any dry, flowable seed or grain product
  • Counterbalanced construction reduces vibration and extends machine life
  • Automatic discharge system maintains consistent bed depth automatically
LMC Marc Series gravity separator for seed and grain processing — high-capacity density separation machine
Density
Separation Method
Ripple Deck
Deck Design
Auto
Discharge System
Low Noise
Single Fan Design
Brand Partner

The Marc Series — Industry Standard in Gravity Separation

LMC (Lewis M. Carter Manufacturing) has been engineering gravity separators since 1941, and the Marc Series remains the benchmark for precision density-based separation in seed and grain processing. LMC's continuous research and development has produced a machine that is simultaneously more precise, more durable, and easier to operate than competing designs.

The Marc Gravity Separator's unique ripple deck, automatic discharge system, and fluidized bed design give it a distinct separation advantage — producing cleaner, more consistent finished product than conventional gravity table designs. Vistasort is proud to supply and support LMC Marc Gravity Separators across Canada, backed by our experienced technical team and full parts availability.

Key Features of the LMC Marc Gravity Separator

Every feature of the Marc Series is engineered to deliver more precise separation, less operator intervention, and lower long-term operating costs.

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Ripple Deck Design

The Marc's ripple deck surface provides greater product traction during the separation process — achieving a more complete and distinct product separation than smooth-deck designs. The ripple pattern creates the ideal conditions for density stratification at high throughput.

Automatic Discharge System

The pressure-driven automatic discharge system continuously senses product bed depth and adjusts the discharge gate to maintain consistent separation — eliminating the need for constant manual monitoring and adjustment as product flow fluctuates during operation.

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Multi-Light Adjustable Gates

Adjustable multi-light gates enable precise control of light product discharge, allowing operators to fine-tune the separation point and tailor output quality to exact specifications for different crops and defect profiles.

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Greater Bed Depth

The Marc Series uses a greater bed depth than competing gravity separators — a counterintuitive advantage that actually uses the product itself to achieve more precise separations. Greater bed depth allows better density stratification throughout the entire product mass.

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On-Deck Recirculation

On-deck recirculation eliminates the need for middle cuts — reducing additional product handling that causes damage. Unlike other gravity separators that produce blended middle cuts requiring re-processing, the Marc handles it on the deck in a single pass.

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Single High-Efficiency Fan

The fluidized bed is created using a single, super-quiet, high-efficiency fan — providing consistent, uniform airflow across the full deck surface while minimizing noise and energy consumption compared to multi-fan designs.

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Counterbalanced Construction

The Marc's counterbalanced frame design greatly reduces operational vibration — protecting the machine's mechanical components, extending service life, and reducing noise and wear on the surrounding facility structure.

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AC Inverter Motor Controls

AC inverter controls with digital RPM display on both eccentric and fan motors allow precise micro speed adjustments — giving operators fine control over separation parameters without mechanical intervention.

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Heavy-Duty Frame Construction

Built with heavy-duty frames and precise mechanical design throughout, the Marc Series delivers the reliability and durability that directly impacts a processing facility's bottom line. Customers consistently report decreased repair frequency and reduced downtime versus competing designs.

How a Gravity Separator Works

The LMC Marc gravity separator uses three physical forces working together to achieve precise density-based separation in a single continuous pass.

1

Product Infeed

Pre-cleaned seed or grain is fed onto the deck at a controlled, consistent rate. The product should be pre-cleaned by an air screen cleaner before entering the gravity separator for optimal separation results.

2

Air Fluidization

A single high-efficiency fan forces air upward through the deck surface, creating a fluidized bed condition where the product mass becomes semi-suspended — allowing density differences to drive separation.

3

Vibration & Stratification

Controlled deck vibration moves product across the ripple deck surface while airflow causes denser material to sink and lighter material to rise — stratifying the product mass into distinct density layers.

4

Deck Angle Separation

The deck's adjustable incline causes the stratified layers to travel at different speeds — heavy product moves uphill while light product flows downhill — separating them into distinct discharge streams.

5

Automatic Discharge

The automatic discharge system continuously monitors bed depth and adjusts gates to maintain optimal separation, directing heavy product, light product, and mid-fractions to separate outlets.

LMC Marc Series gravity separator machine showing deck and separation mechanism
Three Outputs
Heavy Product
High-density, premium grade finished product
Mid Fraction
Re-processable product for secondary cleaning
Light Product
Low-density rejects, damaged kernels, foreign material

LMC Marc Series — Model Specifications

Three models are available through Vistasort to match your throughput requirements — from mid-capacity processing lines to high-volume commercial operations.

Model Capacity Eccentric HP Fan HP Best For
Marc 300 310 cu. ft. / hr 3 HP 7.5 HP Mid-capacity seed processing lines and specialty crops
Marc 400 370 cu. ft. / hr 3 HP 10 HP Commercial seed conditioning and edible bean processing
Marc 500 620 cu. ft. / hr 3 HP 15 HP High-volume grain processing and large-scale seed operations

* Capacities are approximate and vary by product type, density, and moisture content. Contact Vistasort for a capacity assessment specific to your crop and processing requirements. Optional features include dust hood and stainless steel product contacts.

What Can the LMC Gravity Separator Process?

The Marc Series gravity separator works with any dry, flowable product — making it one of the most versatile machines in a seed and grain processing facility.

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Cereal Grains

Wheat, barley, oats, and other cereals benefit significantly from gravity separation — removing shrunken, frost-damaged, and diseased kernels that pass through screens but have measurably lower density than sound grain.

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Pulses & Edible Beans

Lentils, peas, chickpeas, navy beans, and other pulse crops are among the most common gravity separator applications — removing splits, immature seed, and lightweight contaminants to improve export-grade purity.

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Specialty Crops

High-value specialty crops with tight purity tolerances rely on gravity separation to meet export and food-grade specifications — separating off-types and damaged product that cannot be removed any other way.

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Oilseeds

Canola, flax, sunflower, and other oilseeds benefit from gravity separation to remove lightweight, immature, or damaged seeds that reduce oil quality and extraction yield in downstream processing.

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Grass & Forage Seeds

Lightweight grass and forage seeds present unique separation challenges. The Marc's adjustable airflow and sensitive deck controls allow precise separation even for products with very small density differences.

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Seed Conditioning

Gravity separators are a critical final polishing step in seed conditioning programs — ensuring maximum germination rate and vigor by removing low-density seed that would reduce stand establishment in the field.

LMC Gravity Separator in Action

See the LMC Marc Series gravity separator at work in real seed and grain processing facilities supplied and supported by Vistasort.

Gravity Separator FAQ

Answers to the most common questions about how LMC Gravity Separators work and where they are used in real-world seed and grain processing operations.

What does a gravity separator remove from seed and grain?
A gravity separator removes low-density material such as light seed, damaged kernels, weed seed, shrunken grain, and foreign material that cannot be removed by screening alone. It targets density differences between good product and contaminants — separating material that is the same size and shape as premium product but lighter in weight.
What crops can the LMC Marc Gravity Separator handle?
LMC Gravity Separators are used across cereals, pulses, edible beans, oilseeds, grass seeds, and specialty crops. The Marc Series can work with any dry, flowable product — with simple adjustments to deck angle, fan speed, and eccentric speed to match different product characteristics.
How is a gravity separator different from a color sorter?
A gravity separator separates product by density, while an optical color sorter separates by visual characteristics like color, shape, or surface defects. The two machines target different types of defects and are highly complementary — many seed and grain processing facilities use both in sequence for maximum purity and yield.
What is the difference between a gravity separator and an air screen cleaner?
An air screen cleaner separates seed and grain by size and shape using screens and airflow. A gravity separator separates by density, removing material that is the same size as good product but lighter in weight. Most processing lines use both — the air screen cleaner first for sizing, then the gravity separator for final density-based polishing.
Is the LMC Gravity Separator suitable for high-capacity operations?
Yes. The Marc Series is designed for continuous, high-capacity processing. The Marc 500 handles up to 620 cubic feet per hour, with consistent separation accuracy and minimal operator adjustment. Multiple units can be run in parallel for very high throughput requirements.
How long has the LMC Marc Gravity Separator been used in seed processing?
The LMC Marc Gravity Separator was originally engineered in 1941 — making it one of the longest-standing and most refined gravity separator designs in the industry. Over 80 years of continuous development has produced a machine with proven reliability, precise separation, and simple operation.

Get the LMC Gravity
Separator Working for You

Contact Vistasort to discuss your crop, throughput requirements, and processing goals — we'll recommend the right Marc Series model for your operation.