Design Project 4 Report

  • Published on
    04-Mar-2015

  • View
    42

  • Download
    7

Embed Size (px)

Transcript

20101

Team Foxtrot Flora Vinson, Jason Ressler, Kathryn Chinn, Sandra Nakasone, Dimple Patel

Measuring Flow rate: Discrete vs. Continuous flow meters in a hydrometer1

Table of Contents Table of ContentsAbstract....4 Introduction.4 Problem Statement...5 A. Process Scheme...5 Figure 1.6 B. Preliminary Device...7 C. Prototype Device..8 Figure 2........10 Figure 3.10 Figure 4.11 D. Head Tank and Piping......11 E. Solenoid valves...........12 F. Continuous flowmeter.....12 Figure 5.12 G. Discrete flowmeter...13 Figure 6.........13 H. Circuit Board.14 Figure 7.14 I. 1208LS USB computer control........15 J. Computer Programming.......15 K. Materials and Costs..........16 Table 1.......16 Table 2......17 L. Results.......18 Figure 8 .............192

M. Limitations........20 N. Appendix... ..22 Operating Instructions....22 Programming...23 O. References.. 26

3

Abstract The flow meters This project's primary objective was to compare the efficacies between two types of flow meters: a continuous flow meter and a discrete flow meter. To pump water throughout the system, a 12-V pump was used in conjunction with solenoid valves and a -inch piping system. In the project, the preliminary device was slightly adjusted to create the prototype device. In the prototype device, a 2-step gear/DC motor system was used to measure the volumetric flow rate of the continuous flow meter, and an infrared emitter detector was utilized to measure the volumetric flow rate of the discrete flow meter. In the simulation of the prototype device, Microsoft Visual programming was used to gauge the volumetric flow rates. Although the simulation was intended for 1000 seconds, the simulation ran for only 60 seconds, which yielded a volumetric flow rate of 4.6 ml/sec for the discrete flow meter. Likewise, the head tanks reference volumetric flow rate was 6.0 ml/sec. However, because of excess friction and unsteady motion of the turbine flow meter, results were not obtained for the continuous flow meter. In future device modifications, a different two-step gear should be implemented in order to reduce the resistive forces against the turbine flow meter; also, the turbine flow meter should be made out of clear material in order to ease the use of an infrared emitter detector. Under the assumption that the device worked, the cost of a large-scale version of the device turned out to be $5044.24. If a water bottle company used this device, then it would take 5.6 days to offset the devices cost, which is an entirely reasonable price and time to pay for an efficient machine.

Introduction Water is an integral and peripheral part of many industrial operations throughout the world. In order to properly and efficiently utilize an invaluable source like water, a flow meter system needs to be implemented to successfully measure key components of the liquid at hand. For instance, flow meters are used in measuring the rate of flow in fish farms throughout the world; at the correct speed, water in fish tank can be adjusted such that there is an adequate dispersion of feed to the fish stock1. In another application, the U.S. Geological Survey (USGS) measures stream flow of various rivers in North America in order to compile data for studies on climate change, weather patterns, oceanic flows, water levels, ecosystems, and natural hazards2. Flow meters are imperative for processing and handling liquids other than water. For example, in a more local application of flow meters, a tailored flow meter is used in the processing of the highly viscous orange juice, whose pulp interferes with measurements of sugar concentration without proper data on flow3. In terms of another liquid like alcohol, the Auper flow meter was developed in such a way that the turbine within the device helped prevent foam from developing on top of the beer4.

4

In this project, a prototype device was constructed in order to compare the efficacies between two types of flow meters: a continuous flow meter and a discrete flow meter. This comparison will help in providing data for industries (e.g. such as the aforementioned fish farm, USGS, orange juice factory, and beer company) purchasing the optimal, most accurate flow meters for handling their specific liquids. Although there are other types of flow meters in industrial use, the focus of this project was on the discrete flow meter and continuous flow meter because they were commercially available.

Problem Statement This project aimed at comparing the efficacies of two flow meters, a continuous flow meter and a discrete flow meter. An adjoining head tank provided the reference flow rate. To control water input into the aforementioned devices, a solenoid valve system was implemented adjacent to the girder containing the aforementioned head tank and two flow meters. Nonetheless, as with most practical applications, there were constraints on the materials available for this project; therefore, a broad-scheme comparison of many flow meters was not possible. Also, for this project, a 1208LS USB Computer control interface, a circuit board, and Microsoft Visual programming created automated control of the prototype device. Ancillary materials included infrared emitter detectors adjacent to the discrete flow meter; a two-step gear system for the continuous flow meter; a DC motor for the continuous flow meter; solenoid valves; an electric pump; a girder; and a network of -inch clear piping to transport the water from the solenoid valves to the various tank and flow meters.

A.

Process Scheme

A plan of action, as illustrated in Figure 1, served as guideline for the engineering design team. Fortunately, enough time was allotted to adjust the preliminary design. However, problems encountered with its materials forced reworking the preliminary design such that measurements from the continuous flow meter were obtained in a different, albeit easier manner. Unfortunately, this reparative move did not stymie the subsequent problem encountered with rotating the continuous flow meter to yield flow rate results. Nonetheless, for future projects, the somewhat efficient prototype can be improved upon in order to obtain comparative data from both the continuous and discrete flow meter.

5

Figure 1: Process Scheme of Flow Meter ProjectPurpose: To design a device that will compare the efficacies of two different types of flow meters

Brainstorming Session Final idea: Only one emitter detector used in the tilt scale (i.e. continuous flow meter). The turbine flow meter was fixed to a two-step gear, DC motor system in order to ease rotation. Microsoft Visual programming redone.

Original idea: Build a hydrodynamic toy set that will have a turbine flow meter and a tilt scale.

Testing Process Testing Process SUCCESS: Test Simulation succeeded with 1 infrared emitter detector per flow meter. FAIL: Test simulation failed in adding the emitter detectors to the continuous flow meter (i. e. turbine flow meter). Another way of detecting flow changes needed.

Completed programming. Rerun the simulation to yield results. Brainstorming Session

SUCCESS: Tilt scale discretely moved, and turbine flow meter continuously rotated. Comparable results and repeatable simulations were developed.

FAIL: Turbine flow meter only budged slightly in its rotation. Tilt scale yielded verifiable results.

Final Presentation and a report.

6

B.

Preliminary Device

A two-flow meter device was constructed in order to compare the efficacies of the continuous flow meter and the discrete flow meter. In order to ease the visualization of these aforementioned flow meters, the continuous flow meter may be referred to as a turbine flow meter, and the discrete flow meter may be referred to as a tilt scale. As indicated by Figure 1, the preliminary device had a solenoid valve system that was situated in a bigger, white base. The base also held a twelve-volt water pump that worked at 1.8 amperes. The solenoid valve system was placed adjacent to the girder. The girder held the head tank at a head of approximately 17.44 inches from the ground, given that the ground was a reference frame in which the white base was at a position of zero in the zenith direction (given that the zenith direction was orthogonal to the ground, or the horizontal axis). Moreover, the girder held the turbine flow meter and the tilt tank at approximately the same height in the zenith direction; both of these aforementioned flow meters were approximately five inches from the ground in the zenith direction. For the tilt scale flow meter, an infrared emitter detector system was situated such that the emitter was parallel to the left side of the triangular prism that makes up the tilt scale; the detector was parallel to the right side of the triangular prism. Another infrared emitter detector system was set up such that the emitter was parallel to the left side of the turbine tank and the detector was parallel to the right side of the turbine tank. Next, appropriate -inch plastic tubing was used at appropriate lengths in order to connect the water pump to the top of the head tank, the bottom of the head tank to the two top valves of the solenoid valve system, one bottom valve to the discrete flow meter, one bottom valve to the continuous flow meter, the continuous flow meter to the white base, and the discrete flow meter to the white base. For the trial simulation, the bottom base was filled half-way to the brim for the simulations. Filling the bottom tank helped cover the inlet of the electric pump at the bottom of the system. The water pump in the base powered the movement of the water to the top of the head tank. This water flowed down the head tank to the two top valves of the solenoid bank system. The head tanks volumetric flow rate was measured using a simple stop watch as the parameters of the head tank were known; the head tanks volumetric flow rate was used as the reference flow rate. Then the water flowed from these two top valves from the solenoid valve bank via -inch plastic tubing that was joined by an L-connector. Then the water flowed through the solenoid valve bank to either of the banks bottom two valves. One of the bottom valves then pumped the water to either of the flow meters.

7

Next, for the discrete flow meter, the one-inch thick triangular prism that makes up the tilt tank was filled to the brim; when a mass of water that filled the tilt tank equaled the weight of its metal counter weight (which held the tilt tank at a slight angle above the horizontal axis), then the tilt scale rotated 180 degrees such that it moved from the positive to the negative zenith direction (from 90 degrees to -90 degrees in the zenith direction if 90 degrees was measured counterclockwise from the horizontal direction). The infrared emitter detector system was set up such that the emitter emitted infrared light to the detector, which was on the right side of the tilt flow; at the initial position, this beam of infrared light was interrupted. However, every time the tilt flow completed a rotation and spilled its liquid contents to the tank below, the infrared light beam was no longer interrupted by the plastic of the tilt scale. Therefore, the programming language recorded the number of times the electronic beam was fully detected by the emitter over a set time interval in order to correspond the number of tilt tank volumes filled to the time interval. Essentially, by corresponding the number of electron beams formed to a set number of volumes filled and dumped over a given time interval, a volumetric flow rate was established. This discrete flow meter simulation was completed after the continuous flow simulation. Switching from the continuous flow simulation to the discrete flow simulation was completed by a command in the programming language and by a shunt valve in the solenoid valve system. Originally, in the preliminary device (which is not pictured but is essentially the same as that of Figure 1 but without a DC motor and a two-step gear system), an infrared emitter detector was set up along the continuous flow meter. However, when the team attempted a simulation, the continuous flow meters inner turbine rotated at a speed much higher than the upper limit of the infrared emitter detector system. This problem was agitated by the fact that an electron beam was formed every time a blade unblocked the emission of light from the emitter to the detector. This phenomena did not occur with the discrete flow meter because the continuous flow meters turbine tank did not necessarily have to fill up its tank in order to unblock the light emission. Moreover, as indicated by Figure 3, the shaft of the turbines rotor inadvertently blocked some of the infrared lights emission such that the detector detected no light at all or a diffuse amount of light when full detection was expected. Therefore, because of these aforementioned problems, the preliminary device was adjusted to fix the continuous flow meter.

C.

Prototype Device

In the project, the preliminary device was slightly adjusted to create the prototype device. As indicated by Figure 2, prototype device still implemented a girder that held the head tank, the discrete flow meter, and the continuous flow meter. The twelve-volt pump was still used to pump the water to the head tank. The water that flowed down the length of the head tank then entered the solenoid valve system through the top two valves and into the bottom two valves. One of the bottom two valves provided water to the continuous flow meter. The other bottom valve provided flow to the discrete flow meter. All of the excess or measured water from the discrete flow meter and the continuous flow meter eventually poured into the white based.

8

However, the prototype device was markedly different from the preliminary device with respect to the configuration of the continuous flow meter. As mentioned before, the continuous flow meters rotor was moving at a high velocity in a turbulent fashion. Therefore, its adjacent infrared emitter detector could not accurately gauge the number of times its light emission was interrupted by the flow meters blades. Moreover, the plastic material of the turbine flow meter created an unintended obstruction for the light emission even when the blades were displaced. Therefore, to amend the aforementioned problems with the continuous flow meter, the prototype device needed to implement a system such that it would be able to better control the otherwise turbulent motion of the turbine flow meter. Therefore, a two-step gear/DC motor system was utilized on the continuous flow meter to not only slow down the rotation of the continuous flow meters rotor blades, but to also create a more steady motion. This controlled motion would mean that the time interval for the light emission detected by the infrared emitter detector would approach a stead...