Amar has been a pioneer, largest manufacturer and exporter of continuous flow reactors in India since many years. Amar Flow Reactors are used by various industries like fine & speciality chemicals, bulk drug (API) pharmaceuticals, dyes, intermediates, paints, agrochemicals, etc. to convert their batch chemistries to continuous flow.

Volume: 100 ml to 200 ltr volume reactors
Heat transfer area: 200-1400 m² /m³
Flow Rate: upto 10000 lph
Pressure Range: up to 50 bar
Temperature Range: -50°C to 350°C
Material: SS-316 / Hastelloy C276
Pinching design optimized to provide high mass transfer coefficient at acceptable pressure drop.
High heat transfer surface area due to pinching.
Scalable to multi-ton production capacity.
It is the most economical reactor in terms of cost / unit volume of reactors.

Working

Stirred tanks commonly used in the industry are completely back-mixed reactors, meaning the concentration in the reactor is same as the outlet of the reactor-this greatly reduces the reaction rates. Plug flow reactors are an alternative to stirred tanks where the concentration is varied in the axial direction of the reactor. Tubular reactors showcase a plug-flow behaviour but the radial mixing in the tubes is limited. Pinching of tubes is shown to tremendously improve the radial mixing in the tubes. This improves the mass transfer as well as heat transfer coefficients, at the expense of additional pressure drop. Our pinching tube design has been optimized using CFD simulations and extensive experimentation which give best results at an optimal pressure drop. These pinched tube reactors have successfully used in many commercial flow chemistry processes.

Fig. Axial velocity comparison between Straight tube and pinched tube (0.54 Kg/s)

Application

These flow reactors are versatile reactors with applications ranging from miscible / immiscible liquid-liquid reactions, liquid-liquid extraction. They can be used in conjunction with our microreactors and conical flow reactors to provide the necessary residence time for desired conversion. Some examples of pinched tube reactors in the industry are as
follows :

Highly exothermic nitration of bromobenzene and benzaldehyde ( with mixed acid and fuming nitric acid, respectively). Pinched tube always helps to achieve a better liquid-liquid dispersion as compared to a segmented flow that is expected in a normal tube. This specific feature helps to achieve better conversion and hence higher yield of the desired isomer when using a pinched tube.
Liquid liquid extraction: With relatively higher mass transfer coefficient values, the pinched tube flow reactor can also be used for liquid-liquid extraction, which is one of the most common separation steps in flow synthesis.
Scalable, sustainable and catalyst-free continuous flow ozonolysis of fatty acids: A gas-liquid reaction of oleic acid with ozone/oxygen mixture is shown to be effectively done in a pinched tube reactor. Typically, any gas liquid reaction leads to an annular regime, whereas pinched tubes help to break this annular flow thereby breaking the liquid droplets in the pinching zones and improving the mass transfer significantly.