Moisture & Caking
Citric and malic acid absorb moisture from the air and cake into hard lumps.
- Our solution
- A closed silo plus discharge aids such as PW SpeedBlow fluidization and bin activators.
- Your benefit
- Reliable discharge into dosing.
Solutions · Acid Storage
Citric, malic, and adipic acid are hygroscopic and cake, stearic acid softens with heat, and acids in general attack metal surfaces. PW Silo Systems designs aluminum and stainless steel silos for powdered acids and tanks for liquid acids – with the material selected for your acid.
Acid Storage at a Glance
An acid silo stores powdered or crystalline acids – such as citric, malic, or adipic acid – close to production for beverages, confectionery, food, or chemical processes. It protects the product from moisture and contamination and feeds it in a controlled way to dosing and mixing.
Acids attract moisture and cake, and together with moisture they can attack metal surfaces. That is why the silo material, the design, and the discharge equipment are selected together with you for your acid. Acids delivered in liquid form are stored in PW TankLine tanks.
Why Acids Are Demanding
Acids are dosed precisely and react with their surroundings. Every challenge below affects product quality and equipment life.
Citric and malic acid absorb moisture from the air and cake into hard lumps.
Acids – especially with moisture – attack metal surfaces.
Stearic acid is waxy and softens with heat – flakes and pellets can stick together.
Lactic and acetic acid are often delivered as liquids.
Fine acid dust is combustible. Filling and conveying release dust into the silo and its surroundings.
Food plants often handle several acids side by side – including allergen-relevant or specialty products.
Silo Materials
We build silos exclusively in aluminum and stainless steel. Carbon steel is not an option for us: its coating is the only protection against corrosion – and acids are corrosive.
Which of our two materials fits your acid silo or tank depends on the acid, its form and moisture, your process, and your site. We select the material and the design with you.
Your Acid Silo System
Silos for powdered and crystalline acids, tanks for liquid acids, plus discharge, blending, and filtration – engineered as one system from one manufacturer.
Storage
Concentric mass-flow discharge without asymmetric flow zones – as standard, site-assembled, indoor, or multi-compartment silos.
Learn moreBlending
Gravity blending and homogenizing with four technologies, including PW ConeBlend with a hopper that is quick to clean.
Learn moreDischarge
Air fluidization for uniform discharge of poorly flowing products – prevents bridging and can be retrofitted to existing silos.
Learn moreDischarge
Vibration from unbalanced motors breaks up cohesive forces, resolves caking, and keeps the outlet clear.
Learn moreFiltration
Dust separation during filling and conveying, in a hygienic design for the food industry.
Learn moreLiquids
Aluminum and stainless steel tanks for liquids – for acids delivered in liquid form, with custom dimensions and nozzle layout.
Learn moreAcids
Products marked “Tested in our lab” are on our list of bulk materials. The others we review with you based on your material data before designing the silo.
Tested in our lab
Citric acid, anhydrous and monohydrate
Citric acid is on our list of bulk materials tested in our lab. Discharge aids are planned for its tendency to cake.
Tested in our lab
Malic acid
Malic acid is on our tested list. A closed silo protects this hygroscopic acid.
Tested in our lab
Adipic acid
Adipic acid is on our tested list. It is used in food and in polymer production.
Tested in our lab
Stearic acid, flakes and pellets
Stearic acid is on our tested list. Storage conditions are reviewed with you for this waxy, heat-sensitive product.
Tested in our lab
Lactic acid
Lactic acid is on our tested list. Liquid lactic acid is stored in tanks, powdered forms in silos – we review the form with you.
Tested in our lab
Acetic acid
Acetic acid is on our tested list. As a liquid it is stored in PW TankLine tanks – material and design are selected with you.
Also tested in our lab:
Send us your material data and we will review the right solution with you:
Acid Check
Type in your acid or any other bulk material to see whether it has already been tested in our lab. The list covers 287 bulk materials.
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Service in the U.S.
With more than 40 years of experience in silo engineering, we support your acid silo project from the first design discussion to commissioning. We deliver to every U.S. state and install with our own qualified personnel.
FAQ
Answers to the questions plant managers, engineers, and buyers ask most often about storing acids in silos and tanks.
These acids are on our list of bulk materials tested in our lab:
Powdered and crystalline acids are stored in silos, liquid acids in PW TankLine tanks. Ascorbic, fumaric, tartaric, and sorbic acid we review with you based on your material data.
Acids – especially together with moisture – can attack metal surfaces. We build exclusively in aluminum and stainless steel, never in coated carbon steel. Which material and which design fit your acid depends on the acid, its form, your process, and your site. We select them with you.
A closed silo protects the acid from outside moisture. Discharge aids such as PW SpeedBlow air fluidization and bin activators break up bridges and caking and keep the outlet clear.
Yes – in PW TankLine tanks in aluminum or stainless steel, designed for the liquid they hold and the space they occupy. Tanks can be combined with silos for powdered products.
In mass flow, the entire silo content moves downward when material is discharged – not just a channel in the center. Your acid leaves the silo in the order it came in (first in, first out), and no product is left behind in dead zones where it could age or cake. Our PW StoreLine silos are designed for concentric mass-flow discharge without asymmetric flow zones.
Fine acid dust is combustible, and many bulk solids carry an explosion risk. For combustible bulk solids we supply explosion-protected silos designed in accordance with applicable codes and regulations. Venting devices – rupture discs or explosion vents – are selected for your silo, your product, and your application. Integrated filters and dust collectors reduce dust during filling and conveying.
The right size depends on your daily consumption, delivery intervals, the number of products, and the space available at your site. PW StoreLine silos are available in a wide range of sizes and diameters, and silos too large for road transport are assembled on site. We size the system with you – without oversized investment.
Yes. We deliver to every U.S. state and support your project with silo transport, field assembly, silo installation and supervision, and site relocation of existing systems.
Very likely. Our silo systems are designed for nearly all free-flowing, granular, and powdered bulk solids. Send us your material details – kernel size, moisture, and how the product is filled and discharged – and we will review the right storage solution with you.
Tell us about your products, required storage capacity, how the silo is filled and discharged, and your site conditions. Based on this, we work out the material, silo type, and configuration with you and send you a detailed quote.
Your Project
Whether you need a silo for powdered acid, a tank for liquid acid, or a complete system, tell us about your requirements. We'll develop a solution that fits your product, your process, and your site.
Send a Request NowWhat Happens Next
Tell us about your bulk material, your process, and your site conditions.
We work with you on material, silo type, and configuration – based on a bulk material analysis if needed.
You receive a custom-engineered solution with a detailed quote.