Frequently Asked Questions

It depends on how much heat stress your material tolerates and how much throughput you need. Short path molecular distillation operates at the highest vacuum with the condenser only centimetres from the evaporating surface, giving the shortest possible residence time — the right choice for heat-sensitive, high-boiling compounds such as APIs, essential oil fractions and vitamin esters. A wiped film evaporator handles higher feed rates and more viscous or solids-containing streams, because the wiper blade continuously renews the film and prevents fouling.

As a rule of thumb: highest purity on delicate material → molecular distillation; continuous throughput on tough or viscous material → wiped film. Glass models suit laboratory and visual process development, stainless steel models suit pilot and production scale.

Match the model to your sample count, solvent and required reproducibility.

• A water bath nitrogen concentrator gives uniform, gentle heating to 30–100 °C and is the most economical choice for routine batches of 12–60 samples in aqueous or common organic solvents.
• An enclosed dry block nitrogen evaporator needs no water, reaches higher temperatures, and suits small volumes, aggressive solvents and applications where cross-contamination must be avoided.
• An automated endpoint nitrogen evaporator uses sensor-based volume detection to stop each position at a preset volume — the best fit for regulated laboratories, trace analysis and any workflow that demands walk-away automation and batch-to-batch consistency.

Start from purity, then size on peak flow.

Membrane generators typically deliver 95–99% purity and suit blanketing, purging, packaging atmosphere control and general lab use where 99% is sufficient — they are compact, need no regeneration cycle and tolerate varied demand.

PSA generators reach 99.9–99.999% purity and are the correct choice for LC-MS, GC carrier and make-up gas, sample evaporation, glove boxes and instruments sensitive to moisture or oxygen.

For sizing, add together the peak consumption of every connected consumer (do not use average flow), add a 20–30% margin, then correct for site altitude, ambient temperature and required dew point. If your demand fluctuates widely, a smaller generator plus buffer storage is usually more economical than a larger generator idling.

Operate with the evaporator temperature high enough to distil the target fraction but below the point where the material decomposes, and keep the condenser surface 40–70 °C cooler than the evaporating surface. Most ANVORE short path systems run in the 0.001–0.1 mbar range; the deeper the vacuum, the lower the required temperature and the lower the thermal stress.

Balance feed rate against wiper speed so the film stays thin and evenly distributed — a feed rate that is too high floods the evaporator and pushes residue into the distillate, while too low a rate starves the film and reduces throughput. Always degas the feed first; dissolved air and light solvents are the most common reason a system will not reach target vacuum.

Keep the process gentle and controlled.

• Position the needle so the gas stream plays just above the liquid surface — never submerged — which creates a soft vortex without splashing.
• Set the bath or block to the lowest temperature that still gives acceptable evaporation speed (typically 30–60 °C for volatile solvent removal) and monitor the endpoint instead of running to complete dryness. Analytes adsorbed on a dry vessel wall are the most common cause of low recovery.
• Use one needle and one position per sample, replace needles regularly and clean the gas manifold between runs to avoid cross-contamination.

For oxygen- or moisture-sensitive compounds, use high-purity nitrogen from your ANVORE generator and seal the vial immediately after concentration.

Most ANVORE equipment needs only light, scheduled attention.

• Before each use — inspect O-rings and ground joints for cracks or hardening and confirm the cold trap is charged.
• Monthly — change or top up vacuum pump oil, clean the condenser and cold trap, check the needle or wiper assembly for wear, and refresh the desiccant in dry block units.
• Annually — replace all elastomer seals and high-wear parts, verify pressure and temperature sensor calibration, perform a leak test at operating vacuum, and inspect heating elements and insulation.

Consumable spares (seals, gaskets, needles, filters, lamps and vacuum pump oil) are available with a 10-year supply guarantee, and replacement parts for common items ship by air within 3–7 working days.

Let’s check these possibilities.

• Cold trap first — if it is saturated or not cold enough, solvent vapour passes straight to the pump and seriously limits achievable vacuum.
• Seals and joints — inspect every elastomer seal, ground joint and hose connection with a leak test, since a single hardened O-ring will defeat an otherwise tight system.
• The pump itself — degraded or contaminated oil, a worn vane set or an undersized pump at your actual operating temperature will all reduce performance.
• The material — moisture, light solvents or dissolved gas in the feed outgas under vacuum and must be removed by degassing or pre-treatment.

Most “vacuum faults” resolve at the cold trap or the seals.