تدريب Shadowing: Centrifugal Pump Basics - How centrifugal pumps work working principle hvacr - تعلم التحدث بالإنجليزية عبر الفيديو
اختر وضع التدريب
كل وضع يفتح غرفة تدريب بملء الشاشة.
132 جمل
إذا كانت الجمل قصيرة أو طويلة جدًا، انقر على Edit لتعديلها.
1
Hey there guys, Paul here from TheEngineeringMindset .com.
2
In this video, we're going to be looking at centrifugal pumps to learn the basics of how they work, the different types and where we use them.
3
You can get more information on centrifugal pumps, shop for parts and accessories or talk to experts on top pump brands like Bell & Gossett,
4
Taco and more by visiting Statesupplier .com who have kindly sponsored this video.
5
Simply click on the link in the video description down below to find out more.
6
Centrifugal pumps come in many shapes, colors, and sizes, but they typically look something like this.
7
The pumps consist of two main parts, the pump and the motor.
8
The motor is an electrical induction motor, which allows us to convert electrical energy into mechanical energy.
9
This mechanical energy is used to drive the pump and move the water.
10
The pump pulls water in through the inlet
11
and pushes it out through the outlet as we take the unit apart we can see
12
that we have a fan
13
and a protective casing mounted at the back of the electrical
14
motor then inside the motor we have the stator the stator holds the copper coils
15
and we're going to look in detail at that a little later in this video
16
concentric to this we have the rotor and shaft the rotor rotates
17
and as it rotates so does the shaft the shaft runs the entire length from the motor and into to the pump.
18
This then connects into the pump's impeller.
19
Some models of centrifugal pumps, like this one, will have a separate shaft for the pump and the motor.
20
Separated shafts are joined using a connection known as a coupling.
21
Coupled pumps will usually have a bearing house which, as the name suggests, houses the bearings.
22
The shaft continues into the pump casing.
23
As it enters the casing, it passes through a gland, packing, and the stuffing box, which combine to form a seal.
24
The shaft then connects onto the impeller.
25
The impeller imparts centrifugal force onto the fluid which enables us to move liquids, such as water, through a pipe.
26
The impeller is enclosed within the pump casing.
27
The casing contains and directs the flow of water as the impeller pulls it in and pushes it out.
28
Therefore, we have a suction inlet and a discharge outlet.
29
At the back of the electrical motor, we see that the fan is connected to the shaft.
30
When the motor rotates the shaft, the fan will therefore also rotate.
31
The fan is used to cool down the electrical motor
32
and it will blow ambient air over the casing to dissipate the unwanted heat.
33
If the motor becomes too hot, the insulation on the coils inside the motor will melt, causing the motor to short circuit and destroy itself.
34
The fins on the outside perimeter of the casing increase the surface area of the casing
35
which allows us to remove more unwanted heat.
36
The electrical motor comes in either three phase or single phase configuration depending on the application.
37
We're going to look at three phase as this is the most common.
38
Inside the three phase induction motor, we have three separated coils which are wound around the stator.
39
Each coil set is connected to a different phase to produce a rotating magnetic field.
40
When we pass AC or alternating current through each coil, the coil will produce an electromagnetic field
41
which changes in intensity as well as polarity as the electrons passing through it change direction between forwards and backwards.
42
But if we connect each coil to a different phase then the electrons will change direction between forwards
43
and backwards at a different time compared to the other phases.
44
This means
45
that the magnetic field of each coil will change in intensity
46
as well as polarity at a different time compared to the other phases.
47
To distribute this magnetic field we rotate the coils 120 degrees from the previous phase
48
and insert them into the stator of the motor casing.
49
This will create the effect of a rotating magnetic field.
50
At the center of the stator we place the rotor and shaft.
51
The rotor will be affected by the rotating magnetic field and will force it to also rotate.
52
The rotor is connected to the shaft
53
and the shaft runs from the fan through the rotor all the way up to the impeller.
54
This way when the rotor rotates so will the impeller.
55
So now by creating the rotating magnetic field within the motor we spin the rotor
56
which spins the shaft and this spins the impeller.
57
Looking at the pump casing we find a channel for water to flow along which is called the volute.
58
This volute spirals around the perimeter of the casing up to the pump outlet.
59
This channel increases in diameter as it makes its way to the outlet.
60
The shaft passes through the seals and into the pump casing where it connects to the impeller.
61
There are many types of impeller, but most will have these backward curved vanes which will either be open, semi -open, or closed with some shrouds.
62
These backward curved vanes do not push the water.
63
The curves rotate with the outer edge moving in the direction of the expanding volute.
64
These vanes will provide the fluid with a smooth path for the water to flow.
65
We'll see that a little later in this video.
66
The impeller is submerged in water.
67
When the impeller rotates, the water within the impeller also rotates.
68
As the water rotates, the liquid is radially pushed out in all directions to the edge of the impeller
69
and into the volute.
70
As the water moves outwards off the impeller, it creates a region of low pressure which pulls more water in through the suction inlet.
71
The water enters into the eye of the impeller and it's trapped there between the blades.
72
As the impeller rotates, it imparts kinetic energy or velocity onto the water.
73
By the time the water reaches the edge of the impeller, it has reached a very high velocity.
74
This high speed water flows off the impeller and into the volute, where it hits the wall of the pump casing.
75
This impact converts the velocity into potential energy or pressure.
76
More water follows behind this and so a flow develops.
77
The volute channel has an expanding diameter as it spirals around the circumference of the pump casing.
78
As it expands, the velocity of the water will decrease, resulting in pressure increasing.
79
This expanding channel therefore allows more water to keep joining and converting into pressure.
80
So the discharge outlet is therefore a higher pressure than the suction inlet.
81
The high pressure at the discharge allows us to force the fluid through pipes
82
and into a storage tank or around a pipe system.
83
The thickness of the impeller and the rotational speed affects the volume flow rate from the pump.
84
But the diameter of the impeller and the rotational speed will increase the pressure it can produce.
85
Centrifugal pumps are represented in engineering drawings with symbols like these.
86
They can vary slightly from this, so do check the drawings information section.
87
NPSH A term you're going to hear is the NPSH, which is the acronym for Net Positive Suction Pressure.
88
We'll briefly cover what this means.
89
There are two letters at the end of the acronym, the NPSHR and the NPSHA.
90
The R is the required NPSH.
91
Each pump is tested for this value, and this can be obtained from the pump manufacturer by the pump's operating chart.
92
Don't worry about this confusing looking chart at this point, we're going to break it down and cover that in detail in a dedicated video.
93
Links to that in the video description down below.
94
The R value is basically a warning or danger point.
95
As the water enters the pump and flows into the impeller's eye, it experiences a lot of energy due to the friction.
96
This will give us a pressure drop.
97
at certain conditions the water flowing through this section can reach boiling point
98
when this occurs we refer to this as cavitation we're going to see more on that in just a moment
99
the other letter was the a
100
and this is the mpsh available this depends on the insulation of the pump
101
and needs to be calculated it considers things such as insulation type
102
and elevation liquid temperature liquid boiling point etc the available pressure should always be higher than the required value.
103
For example if we have an insulation
104
and we calculate the NPSH A as 11
105
but the pump requires an NPSH R of 4 then the pump should be okay.
106
However if we installed a pump
107
that required an NPSH R of 13 then the available NPSH is insufficient and cavitation will occur.
108
So what is cavitation?
109
As we know water can turn from a liquid state into steam or a gas state.
110
We know that water boils at around 100 degrees Celsius
111
and that's because it's at sea level which has an atmospheric pressure of 101 .325 kPa.
112
But if we went to the top of Mount Everest then water boils here at just 71 degrees Celsius
113
and that's because the atmospheric pressure has reduced to 34 kPa.
114
As the atmospheric pressure reduces it becomes easier for the water to boil.
115
So at the suction inlet of the pump we know
116
that there is going to be a pressure drop and
117
if this pressure is less than the vapor pressure of the liquid being pumped then the water can reach boiling point.
118
When this happens cavitation occurs.
119
During cavitation air particles within the water will expand as they reach boiling point.
120
These will then collapse in on themselves very rapidly.
121
As they collapse they will damage the impeller as well as the pump casing.
122
This remove small parts of metal from the surface and if this keeps occurring then it will eventually destroy the pump.
123
Therefore we must ensure the available pressure is higher than the required pressure of the pump.
124
We use centrifugal pumps everywhere.
125
We use them to move liquids from one tank to another or around a system. For example,
126
we might use a small in -line centrifugal pump in our domestic heating circuit to move heated water around the property.
127
We might use a large centrifugal pump to move the condenser water from a chiller's condenser
128
and up to the cooling tower on the roof as part of the centralized cooling system.
129
We're going to look at the type of pumps and their application in our next video in this series.
130
Okay, that's it for this video, but to continue your learning then check out one of the videos on screen now
131
and I'll catch you there for the next lesson.
132
Don't forget to follow us on Facebook, Twitter, Instagram as well as
تنزيل التطبيق
كل ما تحتاجه للتحدث بطلاقة
تقييم النطق بالذكاء الاصطناعيتقييم كل جملة
تدريب IPAأتقن كل صوت
المفرداتابنِ رصيدك من الكلمات
لعبة المفرداتتعلّم أثناء اللعب
نفس القناة
B21
Ohms Law Explained - The basics circuit theory
Daily ConversationUniversity Students
C11
Diodes Explained - The basics how diodes work working principle pn junction
Daily ConversationUniversity StudentsWorking Adults
B21
Air Conditioning System Basics hvacr how does it work
Daily ConversationWorking Adults
B22
How ELECTRICITY works - working principle
Daily ConversationUniversity StudentsWorking Adults
FOR YOU
فيديو موصى به
C11
150 جمل
Parallel Pump Operation
Daily ConversationUniversity StudentsWorking Adults
C11
166 جمل
What's The Best Supercharger? Roots vs Centrifugal vs Twin-Screw vs Electric
Daily ConversationWorking Adults
C12
333 جمل
Basic Introduction To Oil & Gas Well Perforating
Daily ConversationWorking Adults
C11
106 جمل
EDFR GWO BTT Training Center - Nicolas Riou Wind
Daily ConversationWorking Adults
C12
102 جمل
What is Docker? Docker container concept explained || Docker Tutorial 1
Daily ConversationUniversity StudentsWorking Adults
B22
48 جمل
Motor Control Methods Explained
Daily ConversationWorking Adults
C11
362 جمل
How The Economic Machine Works by Ray Dalio
Daily ConversationUniversity StudentsWorking Adults
C16
307 جمل
Broken Bosch Drill. How to repair a Bosch GBH 2-26 SDS Drill.
Daily ConversationWorking Adults
C11
114 جمل
BAS Bootcamp: Day 6 Setting up IO Internally
Daily ConversationWorking Adults
C11
19 جمل
I Made an EMP Device... It Actually Works
Daily ConversationUniversity StudentsWorking Adults
عن هذه الدرسة
في هذا الفيديو، سنستعرض أساسيات المضخات الطرد المركزي وكيفية عملها. سنتعرف على الأجزاء الرئيسية للمضخة ودورها في نقل السوائل مثل الماء. سيساعدك هذا الدرس على تحسين النطق باللغة الإنجليزية من خلال فهم المصطلحات التقنية وتطبيقها بشكل عملي.
المفردات والعبارات الأساسية
- مضخة طرد مركزي - Centrifugal Pump
- محرك كهربائي - Electric Motor
- مروحة - Fan
- الدوار - Rotor
- المغناطيسية المتناوبة - Alternating Magnetism
- قوة الطرد المركزي - Centrifugal Force
- حاوية المضخة - Pump Casing
- مدخل الشفط - Suction Inlet
نصائح للممارسة
لتحسين مهاراتك في النطق، جرب استخدام طريقة التظليل في الإنجليزية، المعروفة أيضاً باسم shadowspeak. استمع جيداً إلى سرعة ونبرة الحديث في الفيديو، وحاول تقليدها أثناء المشاهدة. هذا سيساعدك على تحسين النطق باللغة الإنجليزية بشكل فعّال. إذا كانت سرعة الكلام سريعة بعض الشيء، لا تتردد في إبطاء الفيديو. قم بتكرار الجمل بعد المتحدث مباشرة، مع الانتباه للعلامات الصوتية مثل التوقفات والارتفاعات والانخفاضات في الصوت. هذه الطريقة ستسمح لك بتطوير مهاراتك اللغوية بطريقة تفاعلية وممتعة.
تذكر أن تعلم الإنجليزية عبر الفيديو يجعل التجربة أكثر ديناميكية، لذا استمتع بالعملية ولا تخف من الخطأ. كلما مارست أكثر، ستحصل على نتائج أفضل! هذه الأساليب ستمنحك الثقة اللازمة للتحدث باللغة الإنجليزية بطلاقة.
القواعد في هذا الفيديو
أكثر التراكيب التي يستخدمها المتحدث، مع العبارات نفسها من الفيديو:
| التركيب | في الفيديو |
|---|---|
| المبني للمجهول be + اسم المفعول — التركيز على ما يحدث لا على من يفعله | are joined · is enclosed · is connected |
| جمل الوصل who / which + جملة — معلومة إضافية عن شخص أو شيء | coils which are · along which is · vanes which will |
| المضارع التام have/has + اسم المفعول — حدث ماضٍ ما زال له أثر الآن | has reached · has reduced |
ما هي تقنية التظليل الصوتي؟
التظليل الصوتي (Shadowing) تقنية تعلم لغة مدعومة علمياً، طُورت أصلاً لتدريب المترجمين الفوريين المحترفين. الطريقة بسيطة لكنها قوية: تستمع لصوت إنجليزي أصلي وتكرره فوراً بصوت عالٍ — كظل يتبع المتحدث بتأخير 1-2 ثانية. تُظهر الأبحاث تحسناً كبيراً في دقة النطق والتنغيم والإيقاع وربط الأصوات والاستماع والطلاقة.