Glass Spring Packing

Glass spring packing, also called spring-type glass packing, is a laboratory column packing made from glass. Fine glass is drawn out and formed in a mould into a small spring-shaped ring, and it works by capillary action: the liquid running over the glass wire is drawn out into a thin film across its surface, which spreads the liquid, enlarges the area where it meets the rising vapour, and mixes the two — the basis of the separation. What makes glass the material of choice is its complete chemical inertness. It resists corrosion that would attack a metal packing, and it adds no metal ions to the process, so it is the packing to reach for with aggressive acids and with sensitive systems that must not touch iron or other metals. Its separation efficiency sits in the middle of the range: below that of the metal θ (theta) ring and triangular spiral packings, but above a ceramic Raschig ring, and for corrosion-critical work that trade is well worth making. It is made in sizes from φ4 to φ10 mm. Model RJ-87.

Laboratory packing made of glass, formed into a small spring-shaped ring.
Glass wire draws the liquid into a thin capillary film for gas-liquid contact.
Chemically inert: corrosion-resistant and metal-ion-free, for aggressive acids and metal-sensitive systems.
Efficiency between the metal wire packings and ceramic rings.
Sizes φ4–10 mm; surface 300–400 m²/m³; voidage 85–95%; model RJ-87.

Technial Parameters

Size (D×L)	Surface area (m²/m³)	Voidage (%)	Theoretical plates (per m HETP)	Pressure drop (mbar/m)
φ4×(10–20) mm	400	85	15–25	8
φ5×(10–20) mm	350	88	12–20	8
φ6×(10–20) mm	320	90	10–16	7
φ7×(10–20) mm	300	92	10–15	7
φ8×(10–20) mm	400	93	8–12	6
φ10×(10–20) mm	400	95	5–8	6

Property	Value
Product Type	Glass spring packing (spring-type glass laboratory packing)
Function	High-efficiency mass transfer in small columns; corrosion-resistant, metal-free
Model NO.	RJ-87
Material	Glass (spring-formed glass wire)
Structure	Small spring-shaped ring; capillary liquid film
Sizes	φ4–10 mm × 10–20 mm
Surface Area	300–400 m²/m³
Voidage	85–95%
Theoretical Plates	5–25 per metre
Pressure Drop	6–8 mbar/m
Efficiency	Below metal θ / triangular spiral packings; above ceramic Raschig rings
Key Advantage	Chemically inert: corrosion-resistant, no metal-ion contamination
Applications	Laboratory and pilot rectification; fine-chemical and pharmaceutical packing towers; corrosive acids and iron-sensitive systems
Trademark	RONGJIAN
Origin	China
HS Code	7002320000
Transport Package	Steel drum / ton bag / carton box

Note: the supplied listing shows the material as stainless steel, which is a template error carried over from the metal wire packings; this product is glass, as its description and its glassware HS code confirm.

FAQs

What is glass spring packing, and how does it work?

Glass spring packing is a small laboratory column packing, and, as the name says, it is made of glass and shaped like a spring. Glass is drawn into a fine strand and wound and set in a mould into a little open spring or coil, and a column is filled with a loose bed of these. It separates by the same principle as any packing, by giving the liquid and the vapour a large surface to meet on, but it has a particular trick: capillary action. The glass strand is fine, so the liquid trickling over it is pulled out into a thin, even film that clings across the glass rather than running off in droplets. That thin film spreads the liquid over a lot of surface and keeps renewing the contact with the rising vapour, which is what lets the two exchange material and separate. So a bed of glass springs takes the mixture fed to the column and, stage by stage up the bed, splits it into its lighter and heavier parts. It is a packing for small columns, where a clean separation matters, and its distinguishing quality is the glass itself.

Why choose glass over the θ ring or triangular spiral packing?

It comes down to what the packing is made of, not how well it separates. The metal wire packings, the θ ring and the triangular spiral, separate a little more sharply than glass, so if efficiency were the only concern you would choose one of them. But metal has two drawbacks that glass does not. First, aggressive chemicals, strong inorganic acids in particular, will corrode a stainless-steel packing over time; glass simply does not corrode, whatever the acid. Second, and often decisive, metal can shed a trace of metal ions into the liquid, iron above all, and some processes cannot tolerate that at all: a reaction that is spoiled by iron, or a high-purity product that must not pick up metal contamination. Glass is completely inert and adds nothing to the stream. So the rule is straightforward: where the chemistry is corrosive, or the system must stay metal-free, glass spring packing is the right choice even though it gives up a little efficiency; where neither is a problem, the metal wire packings edge it on performance. Tell us your chemistry and we will say which fits.

Where is it used — which corrosive or metal-sensitive service?

Glass spring packing goes wherever the process is too corrosive or too metal-sensitive for a metal packing. The clearest case is corrosive feeds, distilling or rectifying mixtures containing strong inorganic acids, where a stainless packing would slowly be eaten but glass is untouched. The other is iron- or metal-intolerant systems: processes where even a trace of dissolved iron would catalyse an unwanted reaction, discolour a product, or fail a purity spec, so no metal may contact the liquid. Because glass adds nothing, it is the standard choice there. In practice it is above all a laboratory packing, for rectification columns doing bench separations, small tests and pilot runs, and it carries through into small production columns in the fine-chemical and pharmaceutical industries, where corrosive or high-purity chemistry is common and column sizes are modest. Its inertness and cleanliness are exactly what those sectors want, which is why demand for it has been growing. Send us the mixture and the duty and we will confirm the size and grade.

What is its efficiency and size range, and how does it compare?

Its efficiency is deliberately in the middle of the range for small-column packings. Measured as theoretical plates per metre, the number of ideal separation steps in a metre of bed, it gives roughly 5 to 25 depending on the size, with the smaller rings giving more; that is below the metal θ ring and triangular spiral packings, which reach much higher plate counts, but comfortably above a plain ceramic Raschig ring. Its surface area runs about 300 to 400 square metres per cubic metre, its voidage is high at 85 to 95 percent so it passes flow freely, and its pressure drop is low, around 6 to 8 millibar per metre. It is made in outer diameters from φ4 up to φ10 mm, each a short spring 10 to 20 mm long, with the smaller sizes chosen for narrower columns and sharper separations. In short, it trades a little separating power for total corrosion resistance and a metal-free process, the right bargain when the chemistry demands it. Tell us your column and separation and we will pick the size.

Glass spring packing is a small laboratory column packing made of glass wound into a spring-shaped ring. The fine glass strand draws the liquid out into a thin capillary film, spreading it over a large surface and keeping it in contact with the rising vapour, so a bed of the springs separates the feed stage by stage. Its defining quality is the glass: completely inert, it neither corrodes nor sheds metal ions, which makes it the packing for corrosive acids and for systems that must stay metal-free. Its separation efficiency is a middle choice, as the table shows.

Glass spring against the other small-column packings:

Packing	Material	Efficiency	Best for
θ ring / triangular spiral	Stainless-steel wire	Highest	Sharpest separation, non-corrosive duty
Glass spring	Glass	Middle	Corrosive acids; metal-free systems
Ceramic Raschig ring	Ceramic	Lowest	Simple, low-cost, corrosion-resistant

It is used in laboratory and pilot rectification and in small fine-chemical and pharmaceutical production columns, especially with strong inorganic acids and iron-sensitive systems. It is made in sizes from φ4 to φ10 mm, with a surface of 300 to 400 m²/m³, a high voidage of 85 to 95 percent and a low pressure drop; the per-size figures are in the table above. Tell us your mixture and column, and we will choose the size.