10 Questions You Should to Know about Microliter Ceramic Pump
Choosing the Correct Pump - World Precision Instruments
The range of applications and the criteria used to select a particular pump or injector is broad and complex, and we encourage you to call us at (866) 606- or and speak with an application specialist. In the meantime, here is a listing of our popular pumps and injectors sorted by technology, flow range and special features.
With competitive price and timely delivery, Zmdy Ceramics sincerely hope to be your supplier and partner.
Special features tell you about applications or functionsof the pump. Many of the syringe pumps can be had with an alarm option that alerts you to the end of travel or blocked flow. The onew with the “P” option allow for programmable flow and volume profiles without using the RS232 computer interface.
Frequently used terms:
- Infuse/Withdraw (I/W): Describes a feature of a syringe pump whereby the syringe plunger is held by the pusher so the motor can pull the plunger back, withdrawing fluid, as well as pushing the plunger to infuse it.
- Push/Pull: A feature of syringe pumps which use two syringes mounted back to back so movement of the pusher block will simultaneously withdraw fluid into one syringe and infuse an equal amount from the other.
- RS232: This is a serial interface. Some pumps in the WPI line can be controlled by computer. Simple programs can be created to control the pump rate, the overall volume. Flow ramps or other profiles and temporal sequences can be written. In addition, pumps can be daisy-chained together to create a pump network. In such a network, each pump has its own address and can be controlled separately by the program.
0.35-14mL/min with 2.4mm tubing1Compact design, Remote control AL- Syringe0.-mL/hr1Push/pull AL- Syringe0.-mL/hr2Push/pull (2 networked pumps) SP100i Syringe0.-519mL/hr1Basic 1 Channel SP101i Syringe0.001µL/hr – 35mL/min2Micro Dialysis application SP200i Syringe0.001µL/hr - 145mL/min2RS232 TTL/Footswitch SP220i Syringe0.001µL/hr - 21mL/min10RS232 Infuse Only SP250i Syringe0.001µL/hr - 21mL/min4RS232 Infuse Only SP210iw Syringe0.001µL/hr - 145mL/min2RS232 Infuse/Withdraw SP230iw Syringe0.001µL/hr - 21mL/min10RS232 Infuse/Withdraw SP120p Syringe0.1 µL/hr – 127mL/hr1+1push pull, single cycle SP260p Syringe0.001µL/hr - 86mL/min2+2RS232 push pull, single cycle SP210c Syringe0.001µL/hr - 86mL/min2+2RS232 push pull, continuous UMP3TSyringe0.03nL/min - 10µL/sec1Ultra Micro Infuse/Withdraw RS232 NANOLITER SyringeBolus, 2.3-69nL/Injection1Oocyte Injector, Infuse only MMP SyringeManual 100 µL-1mL syringe1Manual DMP SyringeManual 100 µL-1mL syringe1Digital readout MicrometerPV830PneumaticpL to nL1Injection pressure, holding pressure and vacuum
Choosing the Right Fluid Dispensing Pump - Medical Design Briefs
Choosing the right fluid dispensing pump for a given application is critical. Whether it’s accuracy and precision or the need to perform for millions of cycles, understanding the most suitable types of pumps available is the first step. This article describes several pumps commonly used for medical manufacturing applications. It examines their advantages and disadvantages. In addition, it discusses how to maximize accuracy by minimizing fluid slip, an important factor in the design of any positive displacement pump. It also looks at the importance of testing the fluid prior to determining what pump is best for the application.
Linear Pumps vs. Rotary Displacement Pumps
There are essentially two types of drive systems that control fluid delivery using positive displacement. Linear drive systems and rotary drive systems. Positive displacement pumping refers to a pump that retracts in a cavity to generate volume on the suction side and extends into the cavity displacing the fluid on the discharge. This is a constant for each cycle. Both linear and rotary positive displacement pumps provide exceptional accuracy and precision. However, each method has its’ advantages and disadvantages.
Calibration. In a rotary application, the volume of displacement is a factor of the pump angle relative to the motor axis. Once the volume is calibrated, the pump module can be locked into position. The displacement is adjustable so it should be checked to confirm that calibration is still within specification. In a linear application, mechanical calibration is not required. The pump module is set in a static location, and volume is determined by how far the piston retracts in the cavity. There is no mechanical set point to change volume; only software is used to adjust this parameter.
Cycle Time. Rotary pumps can produce faster dispenses because the rotary valving motion and linear displacement motion are performed simultaneously. A single cycle is controlled by one revolution of the motor. Multiple revolutions will produce larger volumes based on the pumps fixed volume. Cycle time and the ability to produce a more constant flow rate (based on pump revolutions) are the rotary pumps’ strengths. The dispense profile of a rotary pump includes pulsations which are due to the sinusoidal waveform. This offers the unique advantage of firing off small volumes of fluid very quickly. An example of a rotary application would be dispensing microliter range dots of fluid onto a substrate passing through a high-speed automation system.
By contrast, a linear pump must retract from the suction port to draw fluid into the chamber valve to the discharge port, and then eject the fluid. In general, larger volumes require more time, depending on pump size. The linear dispense creates a flat dispense profile with no pulsation throughout the entire chamber capacity of the pump module. If more volume or a longer dispense is required, two pumps may be run out of phase so that one pump is discharging while the other is on the intake stroke. An example of a linear application would be dispensing a constant line over a distance, such as a diagnostic reagent, or precisely filling a substrate with slow absorption rates. Continuous web applications are ideal for this tandem approach.
Syringe Pumps vs. Ceramic Displacement Pumps
Syringe and ceramic displacement pumps are ideal for precise aspirating and dispensing of samples and reagents. They are often used for both analytical and IVD instruments. There are some differences between traditional syringe pumps and ceramic displacement pumps that are important to mention.
A traditional syringe pump is a device that uses a syringe (usually a glass barrel with a Teflon plunger) to move the fluid. The syringe pump is easily replaceable when it fails (which can be often). It also enables the user to change syringe sizes to accommodate different volumes. The majority of syringe pumps work in conjunction with a motorized valve to which the syringe attaches. The timing of the syringe movement and the valve activation (two motors required) are controlled by built-in electronics. The glass barrel and Teflon plunger of the syringe are wear components that must be replaced regularly.
In contrast, a ceramic displacement pump is a single motor mechanism that utilizes an internal ceramic piston to precisely aspirate and dispense fluids. Unlike the syringe pump, there are no serviceable parts to a ceramic displacement pump. The internal sealing mechanism combined with the polished ceramic piston generally last the entire life of the instrument. These pumps often exceed 10 million cycles. Since internal valving is an option (usually two-way solenoid valves are utilized), ceramic displacement pumps are specified to do exactly what is needed for each individual pipetting application. The style depends on the application, but here are some general guidelines.
Consider a syringe pump when:
The instrument can benefit from being able to change syringes easily.
The instrument uses relatively low cycles during the life of the instrument.
Consider a ceramic displacement pump when:
The instrument will perform high cycles (many millions) over its lifetime.
Contact us to discuss your requirements of Microliter Ceramic Pump. Our experienced sales team can help you identify the options that best suit your needs.
Multiple pumps with specific functions are required within the instrument.
The instrument uses a pump where the mechanism is not easily serviced or replaced.
The instrument requires high precision without periodic service calls.
Minimizing Fluid Slip
Fluid slip is a term commonly used to describe the migration of liquid around the internal moving parts of gear, lobe, and vane pumps. It is the volumetric difference between physical component displacement and liquid throughput. Slip loss refers to the liquid that passes through the clearance space (approximately 0. in.) between the piston and the cylinder wall. Since this clearance represents a restrictive passage of essentially constant dimension, the slip rate is determined by viscosity, pressure, and time.
Assuming constant liquid viscosity and pressure, slip will be a smaller factor in a high-repetition rate pump (short time between strokes) than in a low-repetition rate pump. As viscosity increases and pressure decreases, time becomes a less significant contributor to slip loss. The clearance can be modified to compensate for viscosity. The clearance between the piston and cylinder wall can be optimized for any liquid in order to minimize fluid slip.
To minimize fluid slip, the reservoir height and tip height need to be considered. As a general rule, the reservoir height and tip height should be equal. A fluid’s viscosity plays a part in this determination. One way to determine the optimal position of the reservoir and tip is to prime the fluid lines and observe for any fluid movement during idle time. If the fluid moves back in the line, raise the reservoir. If the fluid drips from the tubing, lower the reservoir. The goal is to achieve zero pressure differential over the pump.
Fluid slip is an important factor to consider through the design and build stages of any pump or pump component. It can be critical to the performance of an application. Testing is highly recommended so that necessary parameters are met for each application.
Applications Testing
When a piece of equipment has been installed that doesn’t meet specification or the filling is difficult to control, it can translate into lost or wasted product.
This can cost an organization a tremendous amount of time and money. Whenever possible, it is best to test the fluid (or a placebo) prior to selecting the pump for the application. The benefits of testing include the following:
Testing helps determine the equipment and parameters needed to optimize the process, including any auxiliary equipment (reservoirs, dispense tips) as well as optimal settings.
Prior data testing for the specific filling/dispense requirements helps to understand exactly how the equipment will perform in the process.
It documents the equipment used and the settings necessary to make the application successful. This can be critical for installation and can be an invaluable reference for expanding or refining manufacturing processes later.
It provides access to demonstration or trial equipment to assist in qualifying the process.
It provides a baseline of performance for the application that can be referenced during validation.
Conclusion
Choosing the right fluid dispensing pump requires first understanding an application’s conditions and requirements. Whether it’s displacement volume, cycle time, viscosity, or the need for multiple pumps, simulating the application in the lab can be critical to success on the manufacturing floor. Testing the fluid beforehand is essential to ensure that the optimal pump is selected for the application. Taking the time to evaluate the fluidic requirements in the beginning ensures success and productivity for the long term.
This article is a compilation of blog posts written by the technical sales team at IVEK Corporation, specialists in the design and manufacture of precision liquid ceramic dispensing pumps and valves, North Springfield, VT. For more information, visit here .
If you want to learn more, please visit our website Ceramic Filling Pump.