Fluid Mechanics And Machinery Set 6

Answer: cast iron

Explaination:
the cylinder of reciprocating cylinder is made up of cast iron. sometimes it is also made of steel alloy. the movement of piston is obtained by a connecting rod which connects piston and rotating crank inside the cylinder.

Answer: closed

Explaination:
the higher discharge valve line holds the discharge valve closed. this helps in maintaining the valve safely.

Answer: force pumps

Explaination:
reciprocating pumps are also

Answer: number of cylinders

Explaination:
reciprocating pumps are classified according to the number of cylinders. and also it classified according to the number of piston sides.

Answer: bicycle pump

Explaination:
simple hand operating pump is also called as bicycle pumps. it is the simplest pump that is used to inflate bicycle tires and various sporting balls.

Answer: shock waves

Explaination:
at high pressure, the voids can generate shock waves. cavitation usually occurs due to the changes in pressure. the pressure change is so rapid that it leads to formation of liquid free layers or cavities that start to affect the overall performance.

Answer: true

Explaination:
bicycle pump generates more compression than volume displacement.

Answer: single acting

Explaination:
power operated pump in which only one side engages the fluid displacement is called as single acting reciprocating pump. it consists of piston in only one side of the fluid being displaced.

Answer: double acting

Explaination:
power operated pump in which both the side engages the fluid displacement is called as double acting reciprocating pump. it consists of piston in both the side of the fluid being displaced.

Answer: axial flow

Explaination:
an axial flow pump is a type of centrifugal pump that uses an impeller with vanes that direct the flow axially. axial flow

Answer: centrifugal pump

Explaination:
centrifugal pump is not a positive displacement pump. reciprocating pumps move liquid by means of a constant back-and-forth motion of a piston, plunger, or diaphragm within a fixed volume or cylinder. reciprocating pumps can handle viscous and

Answer: reciprocating pump

Explaination:
reciprocating pumps are generally designed to pump in low flow, high head applications. one of the most extreme of these applications is water jet cutting, where only a few gallons pass through the pump per minute, but exceed pressures of 10,000 psi.

Answer: priming

Explaination:
most pumps are not self- priming. in other words, the pump casing must be filled with liquid before the pump is started, or the pump will not be able to function. in case the pump casing gets filled with vapors or gases, the pump impeller becomes gas-bound and incapable of pumping.

Answer: centrifugal pump

Explaination:
typical dairy pumps are the centrifugal, liquid-ring and positive displacement pumps. the three types have different applications. the centrifugal pump is the type most widely used in dairies.

Answer: low viscosity products

Explaination:
the centrifugal pump can be used for pumping of all liquids of relatively low viscosity which do not require particularly gentle treatment. it can also be used for liquids containing relatively large particles, provided of course that the particle size does not exceed the dimensions of the impeller channel.

Answer: gentle treatment with high viscosity

Explaination:
this type of pump has 100% volumetric efficiency (no slip) when the viscosity exceeds approximately 300 cp. because of the sanitary design and the gentle treatment of the product, this type of pump is widely used for pumping cream with a high fat content, cultured milk products, curd/whey mixtures, etc.

Answer: peristaltic pumps

Explaination:
in peristaltic pumps, during rotation, the medium (liquid or gas) inside the hose is transported to the lower outlet connection. this creates a vacuum on the suction side, and the product is drawn into the pump. the pump is self-priming and is therefore suitable for emptying barrels with juice concentrates and anhydrous milk fat (amf).

Answer: radial and then axial

Explaination:
francis turbine is radial flow reaction turbine. though the water enters the turbine tangentially, it enters the runner radially inward and flows outward along the axis of the runner.

Answer: available head is partly converted to pressure head and partly to velocity head

Explaination:
since francis turbine is a reaction turbine, part of the available head is converted to velocity head. it is not entirely converted to velocity head. the rest of the available head is converted into pressure head.

Answer: aerofoil

Explaination:
smooth flow and flow without separation (eddiless flow) can be ensured when the cross sectional profile of the guide vanes are aerofoil in nature. aerofoil shape is used in airplane wings to ensure smooth flow too. rectangular profiles are not effective in guiding the water into the runner. elliptical profiles will cause more drag, finally ending up with turbine inefficiency.

Answer: slow runner

Explaination:
considering the velocity diagram of francis turbine at the inlet for a slow runner, we notice that the whirl velocity exceeds the blade velocity along the same direction. they are equal in case of a medium runner.

Answer: fast runner

Explaination:
considering the velocity diagram of francis turbine at the inlet for a fast runner, vane angle is an obtuse angle. whereas, it is right angle for medium runner and an acute angle for a slow runner.

Answer: vw1 / u1

Explaination:
in medium runner, vf1 = vr1 & vw1 = u1. vw1 and u1 are along the same direction, hence that cannot be written as tan (α1).

Answer: vr1

Explaination:
vr1 is the relative velocity of the water flow as seen from the blade. thus, relative velocity is along the direction of the curvature of the blade.

Answer: guide vane angle at inlet

Explaination:
the angle between v1 and the blade velocity u1 is α1, which is the guide vane angle at the inlet.