Fox Valve is the leading global supplier of venturi eductors and venturi transport systems for pneumatic conveying of powders, pellets, and bulk solids. They enable the use of low pressure air (below 14 psig or 1 bar) to be used to move powders, pellets, and bulk solids with no moving parts. Fox has sold venturi eductors continuously since our first sale, in 1963, of a stainless eductor for use in transporting plastic pellets with air at 4 psig.
Fox Venturi Eductors - What are they?
Fox Venturi Eductors convert the output of a blower into suction that can be used to entrain and feed powders, pellets, and bulk solids into a pneumatic conveying system. Because they have no moving parts, they can operate almost entirely maintenance-free.
The eductor acts to compress the air/solids mixture to a pressure adequate to overcome losses in the downstream convey line.
How are they used in pneumatic conveying systems?
Fox Venturi Eductors are used to feed bulk solids, such as powders, pellets, flakes, and particulates, into positive, dilute-phase conveying systems. They are commonly used in place of rotary valves where airlocks simply cannot perform adequately.
Eliminating the rotary airlock, left, with a venturi eductor, right, permits product feed with no moving parts for maintenance-free conveying
For detailed information on eductors - Download Bulletin 301 or request that we mail you a full color, hard copy of Bulletin 301.
Why are eductors used in pneumatic conveying systems?
Fox Venturi Eductors have No Moving Parts - allowing for maintenance-free feeding of bulk solids. In applications involving fine, abrasive, or irregularly-shaped products, this is an enormous advantage. Replacement of existing rotary airlocks with venturi eductors makes for simpler, more reliable conveying systems. Designing with eductors from the beginning ensures the most reliable product feeding available.
No Blowback - All rotary airlocks have blowback. If the product conveyed is fine or abrasive, blowback can cause extreme wear problems. Even with free-flowing products, blowback can be a problem, causing bridging and housekeeping problems, or even an explosion hazard. When installed beneath baghouses, screw conveyors, or dust collectors, airlocks can be a major source of fugitive dust emissions, which are eliminated after a retrofit to Fox eductors.
No mechanical shearing - Eductors minimize the shearing, smearing or degradation of product common with rotary airlocks. And, of course, safety is simply not a concern with Fox eductors.
That's all very interesting...
But Can Venturi Eductors Convey My Product?
Let's start with the letter:
Fox maintains an up-to-date datbase of all installations made with Fox venturi eductors: about 4000 listings in 2009. Below is a partial list of only those products conveyed beginning with the letter 'A.' Note that each individual listing, such as 'activated carbon' could actually represent as many as 200 individual installations. Please have us check our database to see if we have conveyed your product!
Abrasive/ Blast Grit
Absorbent, SAP polymer
Acid Powder, Organic
Act Carb +Hy'd Lime
Adipic Acid Fines
Alum, Spent (ALOH)
Ash & Limestone
Ash + Cement
Ash, Flyash at 300° F
Ash Conditioner Additive
Ash, Rice Hull
Alumina Silica Powder
Aluminum Foil trim
Aluminum Oxide Grit
Apple Bits + Almonds
We think there's a pretty good chance we've worked with your product!
Industry Use Fox Eductors?
Although we have sold Fox eductors for use into just about every industry that requires bulk solids handling, we can list a handful of industries here where Fox eductors have been used for decades,in many, many installations. We also list relevent Case Studies which you can request, and which describe specific applictions within this industry:
Conveying: Coal, coke, and alternative fuels; Additives for inhibiting slag build-up on boiler tubes; sorbents for SOx reduction in CFB's; Activated carbon, lime, calcium carbonate, Trona injection for flue gas desulferization (FGD)
Conveying: Minor ingredients to mixing/batching (salt, sugar, spices, vitamins, flavorings, etc.); Milk powders from spray dryers; Coffee beans from bulk bags; Powdered tea from screeners; Rice; Breakfast cereal from coating reels; Snack food extrudate from extruders; Frozen peas from IQF; Whole peanuts from sorters;
Conveying: Plastic pellets with reduced angelhair and fines from hundreds of extruders and compounding lines since 1963; 50+ fiberglass filled pellets with Clean-in-place, ceramic-lined wear resistant eductors; Conveying plastic regrind and flakes that jam airlocks in 10 minutes;
Conveying: Activated Carbon, Sodium Bicarbonate, Hydrated Lime, Pulverized Limestone into ducts and stacks; Sorbent injection in fluidized bed boilers for SOx reduction
Conveying: Hot copper and nickel alloys at 1000°F from calciners; Mica, talc, quartz, and perlite ore from dust collectors; Copper pellets at 400 lbs/ft3 bulk density;
Conveying: Phenolic resin and sawdust for chipboard; Gypsum for sheetrock; Pumice powder for grout; Roofing granules;
Conveying: Silica, Glass Frit, Ceramic dust, Mica
Conveying: Foundry dust from dust collectors; Innoculant to cupolas; Metal grit from grinding stations; Sand and bond
How To Use Eductors in a
Pneumatic Conveying System
Designing New Systems with Venturi Eductors:
As with any conveying system, the three basic questions are: What product? How much? How far? Send us a completed data sheet and Fox engineers will prepare a Performance-Guaranteed quotation on an eductor or a complete conveying system. The quotation will include all relevant operating data.
For Rates up to 15-20,000 lb/hr
For Distances up to 300 ft
Retrofitting Existing Equipment
Retrofitting existing systems with Fox eductors can result in very significant improvements. These may include:
Eliminate airlock wear
Reduce product damage/degradation
Avoid dust emissions and leakage
Facilitate clean-outs if cross-
contamination is critical
Reclaim otherwise discarded product
Fox Eductor/Blower Sub-Systems
Fox Valve can provide almost all of the equipment necessary to enable easy, quick installation of a fully-guaranteed pneumatic transport system.
A Fox Eductor is driven by a positive displacement blower package
A Fox Eductor and regenerative blower are mounted on a mobile cart
Fox can provide any type of blower required, as part of a perfectly matched, guaranteed eductor/blower system - including all required accessories, filters, hose, fittings, etc.
Eductor systems often use one blower to drive many eductors, making for surprisingly simple systems when handling material from multiple outlets, as is common with dust collectors or cyclones, as illustrated below.
Conveying From Multiclones - One blower drives (16) Eductors, conveying ash at up to
with No Moving Parts
Click the arrow below to read the ten Most Commonly Asked Questions (FAQ's) about Fox Solids Conveying Eductors
Fox Venturi Eductors / Fox Valve
Dover, NJ 07801 USA
Tel: 973.328.1011 Fax: 973.328.3651 email@example.com