Why Pump suction pipe line size is bigger than discharge pipe line?
Sunday, 1 August 2021
What is shutoff Head of a pump and how to know total head of a pump if specification plate is missing?
What is total head of a pump?
Total Head: The height from the original liquid surface up to the highest point to which the fluid will be pumped - the discharge point.
How to Know Total Head of a pump if Specification plate is missing on pump?
CALCULATION OF (NPSH)A FOR CENTRIFUGAL PUMP (PUMP IS INSTALLED ABOVE RESERVOIR)
CALCULATION OF (NPSH)A FOR CENTRIFUGAL PUMP:
Question:2
(NPSH)A =P-hfs -Pv ± Z
P(Absolute pressure)= Atmospheric Pressure+ Gauge Pressure=14.7+0=14.7PSIA=14.7*2.31=33.957 feet ≈ 34 Feet
(Tank is open to atmosphere ,so Gauge pressure =0)
(1 PSIA=2.31 feet water column)
hfs (Friction losses)=3.2 Feet
Pv =0.33889PSIA=0.33889*2.31=0.783 Feet
Z= 8 feet (-8 feet due to pump is installed above reservoir)
Now (NPSH)A = 34-3.2-0.783-8=22.017 Feet ≈22 Feet
NB: All four components in the formula need to be calculated in terms of head (unit is feet in this problem)
CALCULATION OF (NPSH)A FOR CENTRIFUGAL PUMP (PUMP IS INSTALLED BELOW RESERVOIR)
CALCULATION OF (NPSH)A FOR CENTRIFUGAL PUMP
Answer:
(NPSH)A =P-hfs -Pv ± Z
P(Absolute pressure)= Atmospheric Pressure+ Gauge Pressure=14.7+0=14.7PSIA=14.7*2.31=33.957 feet ≈ 34 Feet
(Tank is open to atmosphere, so Gauge pressure =0)
(1 PSIA=2.31 feet water column)
hfs (Friction losses)=3.2 Feet
Pv =0.33889PSIA=0.33889*2.31=0.783 Feet
Z= 8 feet (+8 feet due to pump is installed below reservoir)
Now (NPSH)A = 34-3.2-0.783+8=38.017 Feet ≈38 Feet
NB: All four components in the formula need to be calculated in terms of head (unit is feet in this problem)
Saturday, 31 July 2021
CBSE Class-3 Science Chapter-3 What Animals Eat
What Animals Eat:
⦿Different animals eat different types of food.
⦿Based on the type of food they eat, animals are divided into three types.
Herbivores:
⦿The animals who eat only plants, such animals are called plant- eating animals or herbivores.
Examples: Cows, goats, deers, giraffes, sheeps and elephants etc.
Carnivores:
⦿The animals who eat only flesh of other animals, such animals are called flesh-eating animals or Carnivores.
Examples: Wolves, lions, tigers, crocodiles and some birds such as
eagles and hawks etc.
Omnivores:
⦿The animals who eat both plants and flesh of other animals, such animals are called omnivores.
Examples: Crows, foxes, bears etc.
CBSE Class-3 Science Chapter-8 Air And Water
TOPIC- AIR AND WATER
AIR:
⦿Air is present everywhere and all living things need air to survive.
⦿We cannot see the air, but we can feel it.
⦿Air is needed for breathing , burning, sailing boats, flying
kites etc.
⦿The thick layer of air that surrounds the earth is called atmosphere.
⦿Air is made up of many gases like nitrogen ,oxygen , carbon dioxide
and water vapour.
WATER:
⦿ Like air ,water is also essential for all living things for survival.
⦿We get water when water falls from the sky as rain and fills up oceans, seas, rivers , ponds. Also we get from deep under the ground.
⦿ Water has no fixed shape,It takes the shape of the vessel in which it is poured.
⦿Water exists in three different states i.e solid, liquid and gas.
⦿Solid form of water is called ice, liquid form is called water and gas form is called water vapour.
⦿On Heating or cooling ,water changes its state.
WATER CYCLE:
⦿The important points in water cycle are evaporation, condensation and precipitation.
⦿The rays of the sun fall on oceans, seas, rivers , ponds and lakes.
⦿ This heats up the water ,which changes into water vapour and it rises up .
⦿ The change of water into water vapour on heating is called evaporation.
⦿High up the sky ,water vapour come in contact with cool air .
⦿ Then it forms tiny water droplets.
⦿ The change of water vapour into water droplets on cooling is called condensation.
⦿These water droplets combine together to form clouds.
⦿On further cooling ,the tiny water droplets join to form bigger droplets inside the clouds.
⦿ The cloud become very heavy and the water droplets Fall down as rain.
⦿ This is known as precipitation.
⦿ In very cold places ,water droplets freeze into ice and come down as snow.
⦿ The rain again fills the rivers , ponds ,seas , lakes.
⦿ The continuous change of water from one state to another in nature is called “water cycle”.
Fire Safety Fundamentals
Contents:
👉 What is fire?
👉 What is Fire Triangle?
👉 Fire safety Principle
👉 Classification of fires
👉 Fire extinguishing methods
👉 Types Of fire Extinguisher
👉 Fire extinguisher type vs fire Class
👉 How to use fire extinguisher
👉 What are the fire preventive measures for industry
What is fire?
Fire is a chemical reaction among heat, fuel and oxygen with considering of flash point.
Or
Fire is a chemical reaction in which substance (fuel) combines with oxygen making an
exothermic reaction with the emission of light, heat and smoke.
Three things must be present at the same time to Produce fire:
➤ Suitable Oxygen to sustain combustion
➤ Suitable Heat to reach ignition temperature.
➤ Suitable Fuel or combustible material
Together ,they produce the Chemical reaction that is fire.
What is fire Triangle?
Fire safety principle :
Fire extinguishing works on the principle of cutting off the supply of oxygen to the fire and bringing down the temperature.
Fire safety is based upon the principle of keeping fuel sources and ignition sources separate.
Classification of fires:
Fire Extinguishing methods:
There are three methods for fire extinguishing.
1.Smoothering - Cut off oxygen supply
2.Starvation - Remove fuel source
3.Cooling -Cool the materials
Types Of Fire Extinguisher :
There are different types of fire extinguishers for fire extinguishing.
Fire Extinguisher Type VS Fire Class:
ABC Type Fire Extinguisher :
ABC Fire Extinguishers use mono ammonium phosphate, a dry chemical with the ability to quickly put out many different types of fires by smothering the flames.
●This pale, yellow powder can put out all three classes of
fire:
Class A is for trash, wood, and paper
Class B is for flammable liquids
Class C is for flammable gases
Wet Chemical Type Fire Extinguisher:
Wet Chemical Fire Extinguishers contains a solution of potassium which effectively
attacks the flame in two methods.
● Firstly the mist cools the fire and lowers the temperature to stop the fire spreading, also prevents splashing of the hot oils/fat.
For Metal Fire:
Ternary eutectic chloride (TEC) based dry powder is used for extinguishing metal fires.
Ternary eutectic chloride (TEC) based dry powder is specially formulated eutectic mixture of 3 (ternary) salts for metal fires.
It is treated with speciality chemicals to impart flow properties and excellent water repellency.
How to use fire extinguisher:
What are the fire preventive measures for industry:
Republic Day speech For Kids
Republic Day Speech (For Kids)
Good morning respected principal sir, teachers and all my dear friends.
My name is _________.
I read in ________ class .
I would like to narrate a Republic Day speech in front of you.
Republic Day is celebrated on 26th January every year.
This year, the country will be celebrating its _______Republic day.
Why it is celebrated?
The Constitution of India came into force on 26th of January in 1950, so we celebrate this day as the Republic Day every year.
Republic means self ruled.
India is a republic country which has no any king or queen to rule it however public of this country is the ruler.
How it is celebrated?
The president of India host the Indian flag, singing National Anthem and take salute of armed forces at Rajpath, New delhi.
Awards are also given for bravery & courage.
Also it is celebrated in all schools,colleges etc.
At this day of great honour every Indian people should sincerely promise to support in the development of country.
Thank you, Jai Hind
What is the difference between foot valve and float valve?
A foot valve is found at the end of a pipe line in a suction lift application. They function as a check valve, but they also have a strainer affixed to their open end. The check valve is spring assisted. When the pump turns on, the pressure inside the pump column changes and the valve responds by opening.
Uses:
●Foot valves can prevent the pump column from draining upon pump shutdown.
●These valves are widely used in all kinds of pneumatic system
●They are used in a suction line of the pipeline as Well.
Applications:
●Extraction of water from underground water wells
● Industrial
● Rural fire protection
● HVAC
● Irrigation
● Car wash system
How it Operates:
The valve consists of a cylinder that slides horizontally. In the closed position, the chamber of the float lever presses it against the water inlet to block the water. When the float drops, the piston leaves the gate and allows the water to flow.
Uses:
●This valve can be used to control the water level in a tank for maintaining the proper water level and prevent overflow.
●This valve is capable to open and close itself as the liquid level changes.
●A float is used to mechanically operate this valve.
●The flow of the water is controlled by the rise and fall of the ball.
Applications:
●Water coolers
● Reservoirs
● Sprinkler services
● Swimming pools
● Cooling tower
● Open or closed storage tanks
Friday, 30 July 2021
How to reduce drift loss of cooling tower ?
Reasons for increasing drift loss of cooling towers are as follows.
1.Lack of preventive maintenance
2.Damage of drift eliminator
3.Algae/dust/foreign particles deposition inside drift eliminator
4.No replacement of drift eliminator timely
5.Obsolete technology (drift eliminator model)
6.More gap between drift eliminator (Installation gap)
How to reduce/minimize drift loss of cooling tower?
The following activities can reduce/minimize drift loss.
1.Replace to latest technology drift eliminator
2.proper corrective maintenance of drift eliminator
3.Gap should be closed between two adjacent drift eliminator.
Subscribe to:
Posts (Atom)