The Vapourtec back pressure regulator is a key component of any Vapourtec flow chemistry system. It allows precise control over system pressure during continuous flow reactions, which is critical for optimizing reaction conditions and ensuring consistent results.
What does a back pressure regulator do?
A back pressure regulator (BPR) controls the pressure inside a flow chemistry system. It does this by providing adjustable resistance against the flow, building up pressure. This allows the pressure inside the system to be maintained at a set level, regardless of flow rate fluctuations.
Without a BPR, pressure would vary based on the pumping rate and resistance of the system components. This would lead to inconsistent reaction conditions. The BPR ensures a steady pressure is maintained during a reaction.
Why is consistent pressure important in flow chemistry?
Pressure affects many reaction parameters in flow chemistry, including:
- Solubility of gases
- Rate of mass transfer
- Reaction kinetics and equilibrium
- Phase behavior
By keeping pressure constant, it ensures these parameters do not fluctuate during an experiment. This allows reactions to be accurately optimized and repeated reliably.
Maintaining consistent pressure also prevents cavitation, where bubbles form and collapse in the flow streams. Cavitation can damage flow chemistry equipment over time.
Key features of the Vapourtec back pressure regulator
The Vapourtec BPR has the following notable features:
- Wide pressure range – Can maintain pressures anywhere from 0-140 bar, for both low and high pressure chemistry applications.
- Precise pressure control – Pressure can be controlled to within ±0.2 bar of the setpoint for accurate reaction conditions.
- Chemically resistant – Made from PEEK polymer and other inert materials to withstand a wide range of chemicals.
- Low internal volume – Minimizes unswept dead volume so reactions see consistent conditions.
- Inert flow path – Prevents cross-contamination between experiments.
How does the Vapourtec back pressure regulator work?
The Vapourtec BPR uses a dome-loaded pressure regulation system. It controls pressure through the balance of forces between a compressed dome diaphragm and an adjustable spring.
The key components involved are:
- Dome diaphragm – Flexible dome that compresses under pressure.
- Adjustment screw – Applies force against the dome diaphragm via a spring.
- Inlet/Outlet ports – Fluid flows in/out of the BPR through these ports.
- Sensing port – Measures internal pressure against the diaphragm.
As fluid enters the BPR, pressure pushes against the dome diaphragm. Once pressure builds sufficiently to match the opposing spring force, the diaphragm stops moving. This balances the forces and maintains steady pressure inside the BPR.
Turning the adjustment screw compresses the spring to change the resistive force on the diaphragm. This alters the pressure setpoint. If pressure drops below the setpoint, the diaphragm flexes until balance is restored.
Materials of construction
The Vapourtec back pressure regulator is constructed from chemically resistant materials compatible with a wide range of reagents and solvents. The key materials used are:
Component | Material |
---|---|
Body | PEEK |
Seals | PTFE |
Diaphragm | PTFE |
Fittings | PEEK |
PEEK (polyether ether ketone) is an inert high-performance polymer resistant to almost all organic solvents. PTFE (Polytetrafluoroethylene) is resistant to nearly all chemicals.
This allows the Vapourtec BPR to be used with aggressive acids, bases, oxidants, polar organics, alcohols, amines and more. It has excellent chemical compatibility for a wide range of flow chemistry applications.
Pressure rating
The Vapourtec back pressure regulator is rated for pressures up to 140 bar (2000 psi). This high pressure rating makes it suitable for diverse reaction conditions:
- Atmospheric pressure reactions – The BPR can precisely control pressures down to 0 bar.
- Low pressure chemistry – It can regulate reactions from 0-10 bar.
- Medium pressure chemistry – Pressures from 10-50 bar can be maintained.
- High pressure chemistry – For forcing reactions, pressures up to 140 bar are possible.
This broad operating range lets you optimize pressure to maximize yields, improve selectivity, and control other reaction parameters.
Flow rate specifications
The Vapourtec back pressure regulator can handle flow rates up to 100 mL/min, making it suitable for a range of production scales:
- Analytical screening – Flow rates of 0.1-5 mL/min are handled reliably.
- Process development – It can regulate flows up to 100 mL/min for scale-up studies.
- Pilot and production – Flows up to 100 mL/min allow gram to kilogram scale production.
Higher flow rates are possible by connecting BPR units in parallel. This modular expandability lets you scale up production without needing different pressure regulation equipment.
Temperature range
The operating temperature range for the Vapourtec back pressure regulator is -20°C to 100°C (-4°F to 212°F).
This allows both low temperature chemistry (e.g. reactions done at 0-10°C) and high temperature chemistry (e.g. reactions requiring heated reagent streams up to 100°C).
Heating can be done passively or using heated fluidic blocks. Cooling requires the use of chilled fluidic blocks.
Care must be taken not to exceed the PEEK polymer maximum temperature rating of 150°C when heating. Above this, degradation and seal leaks can occur.
Pressure control precision
The Vapourtec back pressure regulator provides precise control of system pressure. Pressure is regulated to within ±0.2 bar of the setpoint.
This level of precision ensures reaction conditions remain highly consistent during an experiment. It also allows very small pressure changes to be made to finely tune a reaction.
Reactions sensitive to small pressure fluctuations can be optimized using this regulator. Precise pressure control minimizes variability between experiments.
Connection ports
The Vapourtec back pressure regulator uses standard 1/4″ (6mm) fittings for all fluidic connections:
- Inlet and outlet ports use female 1/4″ ports for easy integration into flow systems.
- The sensor port uses a male 1/4″ fitting to connect to tubing measuring internal pressure.
This ensures seamless coupling to other Vapourtec flow chemistry components like pumps, reactors, and analytic equipment.
Internal volume
The Vapourtec back pressure regulator has an extremely low internal volume of just 120 μL. This minimizes unswept dead volume – regions of stagnant flow that can distort reaction conditions.
Low dead volume is critical for flow chemistry. It reduces dispersion so narrow reaction plugs see consistent conditions as they move through the BPR.
Minimizing dead volume also improves analysis, as exit streams more accurately reflect the reaction environment inside the reactor. This helps optimize conditions efficiently.
Bi-directional flow
The Vapourtec BPR allows bi-directional flow through the inlet and outlet ports. Flow can pass through the regulator in either direction.
This makes it easy to integrate into reversible flow systems. The BPR does not dictate flow direction, providing flexibility in how it is installed.
Modular expandability
Multiple Vapourtec back pressure regulators can be connected in parallel to increase flow capacity. This provides a simple method for scaling up flow and pressure regulation.
Using multiple regulators ensures smooth flow at higher rates. Parallel BPRs also provide redundancy if service of one unit is required.
This modular approach avoids downtime associated with conventional regulator servicing. Production can continue uninterrupted during maintenance.
Inert flow path
The Vapourtec back pressure regulator uses an inert PEEK and PTFE flow path. This prevents cross-contamination between different reaction mixtures.
Many regulators use metal components that can corrode or leach traces into the flow streams. The inert flow path guarantees high purity outputs.
This is essential for sensitive reactions like catalytic and pharmaceutical production where trace contaminants can ruin product quality.
Simple integration
Integrating the Vapourtec back pressure regulator into a flow chemistry system is straightforward. It functions similarly to other flow control components:
- Connect plumbing between the reactor outlet and BPR inlet port.
- Connect tubing from the BPR outlet to collection/analysis equipment.
- Connect the pressure sensor port to a pressure gauge or transducer.
- Adjust the regulator screw to set the desired back pressure.
Once connected, the BPR automatically builds and maintains pressure. No external power or air supplies are required. It uses the process fluid to hydraulically self-regulate pressure.
Safety features
The Vapourtec back pressure regulator includes multiple safety features:
- Pressure relief valve – This valve opens if pressure exceeds the regulator rating to avoid damage.
- Shatter-resistant polymer body – The PEEK body resists fragmentation if ruptured.
- Leak-tight seals – Prevents leaks up to the rated pressure of 140 bar.
- Secure fitting threads – Avoiding loose fittings prevents leaks.
These ensure the BPR can be used safely at high pressures without risks of leaks or explosions. It provides robust, fail-safe pressure regulation.
Typical applications
The Vapourtec back pressure regulator is commonly used for the following applications:
- Flow chemistry – Precise pressure control for flow reactors.
- Supercritical fluid extraction – Maintains pressure for supercritical CO2, methanol, etc.
- Microreactor systems – Built-in BPRs for self-contained microreactors.
- Pressure-driven flows – Generating flow by restricting outlet pressure.
- Packed column reactions – Controlling pressure drop across solid catalyst beds.
It is a versatile BPR suitable for both high pressure and low pressure usages across many areas of chemistry and chemical engineering.
Integrated pressure monitoring
The Vapourtec back pressure regulator allows real-time monitoring of system pressure. This is enabled by the 1/4″ pressure sensor port.
Connecting this port to a gauge or transducer provides live pressure measurements. This data can be logged to optimize reactions and troubleshoot issues.
Seeing pressure fluctuations provides insight into how reaction parameters affect back pressure equilibrium. It also verifies the BPR is functioning as expected.
Rapid pressure adjustments
Turning the regulator screw rapidly alters the pressure setpoint. This allows quick, precise adjustments to reaction conditions.
In many back pressure regulators, changing the pressure setting requires slow, gradual adjustment while waiting for equilibrium. The Vapourtec BPR quickly reaches the new setpoint.
This accelerator optimization by allowing you to sweep through a range of pressures when screening reactions. Pressure can be tuned dynamically based on analytic feedback.
Compact, low-profile design
The Vapourtec back pressure regulator has an extremely compact construction. It adds minimal volume to flow systems:
- Small 37 mm x 33 mm x 15 mm size.
- Lightweight at just 200 g.
- Mounts in any orientation.
This makes it easy to integrate into crowded reactor rigs with limited space. It also simplifies scale-up as additional units take up little room.
The low-profile regulator is designed specifically for flow chemistry environments. Traditional large, heavy BPRs are cumbersome in these applications.
Rugged and durable
Vapourtec back pressure regulators are built robustly to withstand continuous usage without failure:
- Withstands pressures up to 140 bar.
- Handles a wide range of temperatures from -20°C to 100°C
- PEEK and PTFE construction resists corrosion and solvents.
- Components are tightly assembled and leak tested.
- Designed for 24/7 regulated flow.
This ruggedness allows it to continually regulate pressures day after day without breakdowns. It provides years of reliable service with minimal maintenance.
Easy maintenance
Maintaining the Vapourtec back pressure regulator is straightforward. All serviceable parts are accessible from the exterior:
- Adjustment screw can be recalibrated or replaced.
- Inlet filter removes any particles that could clog the regulator.
- Seals can be accessed and swapped out.
- Full disassembly is possible for deep cleaning.
No special tools are required. User-serviceable construction minimizes reliance on factory technicians for repair work.
Routine maintenance like cleaning the inlet filter prevents common issues. Parts are readily available for any repairs needing replacement components.
Conclusion
The Vapourtec back pressure regulator provides unmatched pressure control for flow chemistry applications. Its dome-loaded design offers precision, responsiveness, and reliability.
Key features like wide pressure/temperature ranges, bi-directional flow, and integrated monitoring make it a versatile BPR suitable for diverse reactions and scales.
Rugged PEEK/PTFE construction, compact size, and easy maintenance deliver dependable, long-lasting performance. The Vapourtec regulator is the gold standard for regulating flow chemistry pressures.