Waiting for answer This question has not been answered yet. You can hire a professional tutor to get the answer.

QUESTION

I need to Paraphrase this Paragraph as soon as possible

I need to paraphrase this essay as soon as possible so it can fit in profissonial technical report 

Discussion of Results

Based on the data obtained there is a clear difference between the performance of the gear and centrifugal pumps. Both pumps follow their individual properties in which the gear pump the flow rate is proportional to the pump speed and independent of the discharge pressure. The centrifugal pump is a kinetic pump where the discharge pressure is proportional to the pump speed and independent of the flow rate. These properties will be used to explain data obtain for each pump.

Data was collected two separate times exactly a week apart under slightly different conditions. The first week algae had accumulated inside of the vessel water would be pumped out of. For the gear pump several efficiency values were over one-hundred percent while the centrifugal pump was well below that of standard centrifugal pump, starting below five percent efficiency and no higher than twenty percent. To confirm what we obtained the data was ran again under different circumstances.

On week two, the algae within the tank was cleaned and the change in data was evident. Because of the drastic differences in data and having more realistic calculated efficiencies. It is because of this the data obtained on the second day of testing will be used in the discussion of the results.

Three meters were used to find flow rate through the system. These meters include an ultrasonic flow meter, a rotameter, and an orifice meter which calculates the pressure drop across an orifice. For this experiment and to explain our findings we will be using the rotameter to find our flow rate and to calculate our efficienies. Reasoning behind this is because the rotameter is a physical meter where the flow rate is found visually without any calculations. The thought behind this is during calculations, errors can arise which will give various amounts of error as you carry values through the next calculation. By taking data from direct flow in a rotameter, this will allow less error to arise and less error to be multiplied through in various equations giving us the most accurate values possible.

Gear Pump

As mentioned in paragraph one of this discussion, the gear pump's flow rate is proportional to the pumps speed and is independent of the discharge pressure. A gear pump is a type of positive displacement pump where each revolution of the gears pumps a constant amount of fluid per revolution. As the revolutions per minute (RPM) is increased this will create an increase in volumetric flow in a linear fashion. While the volumetric flow and RPM is increased a general trend of an increase in efficiency is shown in figures 8 and 9. Both relationships in which are a linear relationship.

Centrifugal Pump

Centrifugal pumps are kinetic, in which the discharge pressure is proportional to the pump speed and independent to the flow rate. This characteristic is shown in figure 15 where the RPM of the pump and the discharge pressure run in a linear relationship. The start of the data shows a negative orifice meter pressure reading because of a vacuum that forms at lower volumetric flows. As the volumetric flow increases the orifice meter pressure flips back to a positive reading. It is at that point the data for the centrifugal pump will be analyzed because of the normalized trend observed in the efficiencies after this point. The only exception to this trend is when the control valve on the system is turned a fourth time. This causes a drop in efficiency not seen in other trials (turns one through three) and there is also a considerable drop in volumetric flow visible on the rotameter on the fourth turn, a major drop in pressure across the orifice meter, a discharge pressure increase, and a drop in torqu all playing a part in this drop in efficiency. The most likely explanation to this drop is a drop in pressure head within the pump when the control valve is nearly closed. The centrifugal pump creates a vacuum which allows suction at the inlet and positive pressure at the outlet. This pressure change helps move fluid through the impeller of the pump. If there is a change in the pressure head of the pump while in operation this would explain fluctuations in the overall efficiency of the pump.

Conclusion

            In the experiment, we operated and calibrated both the pumps and flowmeters, to allow the experiment to be conducted. By learning the techniques that test both centrifugal and gear pumps, one is able to assume the variation in performance between two pumps as well as the difference in how the pumps fool the flow rate and pressure. Through experimentation, some of the theoretical identification has been addressed. 

To decide on which pump is best for a process requires knowing if pressure needs to be constant, if there will be an adjustments in flow rate, and many other factors. If a flow rate with varying pressure is required to be constant, a gear pump would be better. Gear pumps are much less affected by changes in pressure than centrifugal pumps, making them ideal for those situations. These assumptions were tested and confirmed experimentally.

            Also, the interrelation between motor speed, flow rate, and pressure was able to be investigated for both types of pumps. Higher flow rates lead to higher efficiency with both pumps which in turn matched literature. Another observation to consider is the pumps had different responses between efficiency and motor speed which would need to be taken into account once a pump was selected for the process. For centrifugal pumps, there is a “sweet spot” below their maximum operating speed where optimal efficiency is obtained and diminishing returns occur if the pump is overdriven. Gear pumps seem to have a much more linear response curve which suggests that they handle power nearer to their operational maximum better.

            For both these situations, the operational differences between the two allows one to decide which pump would be better for the system.  Other factors, such as cost, chance of breakdown, and size would need to be investigated as well in a realistic setting. With these set aside and looking at just what the experimental results it can be concluded that enough data was collected to allow one to select between the two pumps.  After investigating results from the experiment the gear pump is found to be more efficient in a wider range of scenarios.

            Lastly, calibration of the various flowmeters and the assessment of their displayed results’ relationship with experimentally collected data was able to be accomplished. With this an accurate comparison of the flowmeters’ responses could be done and since. Since this was done during the previously mentioned experiments on the pumps the experiment allowed the ability to test the flowmeters under a wide variety of pressures and flow rates. None of the flowmeters demonstrated any large inaccuracies but by comparing the variance of the various flowmeters at a set flow rate one would be able to choose the one that has the least variance at a specific flow rate to pick the optimal flowmeter for a given situation.

Show more
LEARN MORE EFFECTIVELY AND GET BETTER GRADES!
Ask a Question