このページには、Engr305 に該当するテクノロジー クラス プロジェクトのドキュメントが含まれています。このプロジェクトは、パルサー ポンプの実用モデルを構築することです。実際にどのように動作するかに関するドキュメントは限られていますが、増え続けています。私のプロジェクトの使命は、メカニズムを実験し、この驚くべき装置を中心に発展する知識体系に私の発見を追加することです。工学部の学生である私にとって、これは設計プロセスを実践する機会であると同時に、あまり普及していないテクノロジーを実験する機会でもあります。
パルサー ポンプは、空気を含んだ水を U 字型構造の底部に引き込み、U 字型の底部で空気を捕捉することによって機能します。この空気は、両側の水柱の重みによって蓄積されるにつれて加圧され、U字型の中にわずかな距離だけ突き出た小さなパイプを強制的に上昇させ、一部の水をチャンバーからより高いところまで運ぶことができます。構造物に入るよりも高い標高（二相流）。私のプロジェクトは、パルサーポンプ機能の複雑さの一部を明らかにし、将来の実験者が効率的な製品を製造するのに役立つことを願っています。比較的平坦な水路での大流量をヘッドに変えることができる製品で、灌漑やマイクロハイドロに使用したり、その他の無数の用途に保管したりできます。
目次
文献展望
トロンプ
トロンプ (トロンベと綴られることもあります) は、水と混合した空気を吸引し、空気を加圧するための機構です。さまざまな長さのチューブが水面に垂直に設置され、その開口部は水面直下にあります。この配置により、水と空気が交互にチューブ内に引き込まれます。最初は重力によって水が、次に少量の水がチューブ内に降下するときに生じる真空によって空気が吸引されます。この切り替えは、パイプ入口のすぐ周囲の水が流入するときに起こります。これは、そこの表面の高さが残りの水の表面の高さに等しくなるまでに時間がかかるためです。水と空気の混合物がパイプを下降すると、空気は水の重さによって加圧されます。(ハント 2010)
エアリフトポンプ
圧力下で空気が水と混合されると、空気は膨張しようとします。出口が十分に小さいと、空気の膨張によって水が出口に押し上げられる可能性があります。この機構を二相流といい、エアリフトポンプを駆動します。流体を上方に持ち上げるのに必要な特定のタイプの二相流は、スラグ/プラグ流です (Stepanoff 1965)。二相流については、ここでさらに詳しく説明します。
ヘッドと流れの一般的な仕組み
揚程と流量の原理はパルサー ポンプの機能に不可欠です。
頭
流体が上昇すると、重力による位置エネルギーが生じます。この電位は、水柱内の圧力の量を定量化する方法であるため、水頭、または場合によっては圧力水頭と呼ばれます。水源から水が堆積している場所までの距離は、通常、高さのメートルまたはフィートで測定されます。流体の質量が重力の影響を受ける次元。(サリバン 1975) (詳細)
フロー
流量は、時間に対する体積の尺度です。多くの場合、1 分あたりのガロンで測定されますが、時間あたりの体積の測定はどれでも適切です。(グラフマン 2010)
パルサーポンプ
Brian White, among others, has built a pump that is the union of a trompe and an air lift pump. It uses the trompe to take flow in a stream and pressurize air in the water in a chamber below, this pressurized air then pushes a small amount of the water up though a smaller outtake to a higher elevation than the top of the trompe. The mechanics of the pump are well documented here,this page is devoted more to my design process.(White 2008)
Criteria
ED: INTRODUCE THIS CRITERIA SECTION. These are the criteria by which the success of the project will be judged.
| Criterion | Weight | Constraints |
|---|---|---|
| Cost | 10 | Maximum budget of $100. |
| Concept Demonstration | 10 | Must demonstrate that the concept is sound. |
| Level of Embedded Energy | 9 | The more parts bought used the better. |
| Efficiency | 5 | The higher the flow and the higher it's pumped, the better. |
Budget
| Item | Quantity | Total Cost($) |
|---|---|---|
| 4" pvc | 10 ft | 10 |
| plastic trashcan | 1 | free |
| 45 elbow | 3 | 6 |
| E600 PVC Glue | 1 | 6.48 |
| 3/4" PVC | 15 ft | free |
| Duct Tape | 1 roll | 5 |
| gorilla tape | 1 | 4 |
| 3/4" rubber washer | 1 | .89 |
| large plastic tupperware | 1 | free |
Total Project Cost=$32.37
Design
Process
I spent far too little time in design. I started with some pointers that Brian White gave me and jumped into the physical structure design before I completely understood the math involved. The major flaw in the project is that it was designed to accommodate the energies in a pump for legitimate application and not designed to be a demonstrative model. Despite this major fallback the design meets the three top criteria very well.
Cost: See the budget for details, but note that the pump is built almost entirely from used and therefore free or extremely cheep parts.
Concept Demonstration: However effective/efficient, this design uses elevated water columns and aerated flow to generate a two phase flow regime which brings water higher than it is introduced.
Level of Embedded Energy: This is where the project really stands out; I'm proud of the DIY, creatively driven, see what comes out of the salvage yard method I employed for this project. It was very inexpensive in both energy and money.
It's not the most rigorous experimentation but it was fun and I hope people who read this see that they can have an adventure with science for a small amount of dollars and a few (or many) trips to the salvage yard.
Physical System
The structure consists of four main parts,
The down pipe- 4" diameter, brings air and water down into the chamber, provides head to pressurize air in the chamber. Joins to the chamber with two 45 degree elbows
The out pipe- 4" diameter, brings water back up from the chamber sans-air bubbles, provides head to pressurize air in the chamber. Joins to the chamber with a 45 degree elbow
The up pipe- ¾" diameter, two phase flow regime occurs in this pipe bringing water to the top, three lengths were used 49", 41", and 33". 1½" above the bottom end is wrapped with a strip of gorilla tape to aid the seal with the chamber (air pressure is a wily escape artist).
The chamber- The bottom of an old plastic waste bin I salvaged glued to an old large Tupperware I had lying around. The top hole in the chamber has a ¾" rubber gasket glued over it so that I could test different lengths of "up" pipe. Two other holes I made by tracing my 4" pipe onto the side of the bin, drilling small holes on that circle and then finishing the cut with the handsaw in my multi-tool. The down and out pipes are joined to these holes with E600 multi-purpose adhesive.
Wanna See a Video?
http://www.youtube.com/watch?v=LungrknZtic
Testing/Troubleshooting
As I mentioned before this model was built to accommodate the energies in a real system, more simply, I did not have the amount of flow necessary to carry the quantity of air I needed. My hose flows at.56 L/s and in a 4" pipe that isn't fast enough to bring air bubbles through the chamber in consistently high quantities necessary for the pump to work. To compensate for this problem I sprayed the hose down a ¾" pipe placed in the in pipe (I call this my cheater pipe, it increased air flow into the pump drastically). I know that it in no way mimics the natural system of a trompe but without a creek to stick my pump in I had to get creative. The cheater pipe is 30 in. long. I was able to measure the output by collecting it in a bag taped to the top of the pump (see the picture above).After six sets of flow tests with the above flow rate I compiled the results in the table below.
table key: UP=height of the up pipe(in.),WC=height of the right hand water column(in.),CP=was the cheater pipe used,FR=the flow rate out of the up pipe(mL/min..
Flow Rates w/ Varied Input
| UP | WC | CP | FR |
|---|---|---|---|
| 49 | 24 | no | 4.5 |
| 49 | 18 | yes | 7.5 |
| 41 | 24 | no | 8.0 |
| 41 | 18 | yes | 49 |
| 33 | 24 | no | 36 |
| 33 | 18 | yes | 110 |
note: It seems to me that the obvious correlation of increased pumping height decreasing flow rate is far overshadowed by the extra aeration given by the cheater pipe, leading me to believe that a trompe that provided maximum air flow would yield the best results.
Conclusions/Records
variations and consistencies
In my testing I varied the height of the up pipe, and the the manner in which air was delivered to the chamber. The flow rate of water was maintained throughout, but the cheater pipe allowed the air to flow in faster. The volume of the compression chamber (the volume of air in the chamber fluctuates around this number) was a constant 267 cubic inches, and the extension of the up pipe into the chamber was 1 and 1/4 inches.
Interpretation
The pump rate is inversely proportional to the height water is being pumped to and directly proportional to the flow rate of air in the water and height of the pressurizing water columns. In order for slug/plug flow to
References
Sullivan, J. A. (1975) "Head and Pressure"
Fluid Power: Theory and Applications p. 58,59
Reston Publishing Company, Inc. Reston, Virginia 22090
Cheremisiniff, N. P. (1981) "properties of fluids","principles of fluid flow"
Fluid Flow: Pumps, Pipes and Channels p. 43-47, 163-166
Ann Arbor Science Publishers Inc., Ann Arbor, Michigan 48106
Stepanoff, A. J. (1965) "flow of gas-liquid mixtures"
Pumps and Blowers, Two Phase Flow p 275-280
John Wiley & Sons, Inc.
Hunt, J. R. (2010) "Harness Hydro Power with a Trompe"
Mother Earth News, 02/13/10
Lonny Graffman (2010) "general mechanics of flow and head" Personal Correspondence
White, B. (2008) "Pulser Pump" Appropedia, 02/7/10