PUMP Vs. COMPRESSOR : DIFFERENCE EXPLAINED !!!

Pump and compressor both are hydraulic machines used to increase the energy of fluid. Both of these devices used in industries and for domestic work. Pump is a device which is used to move the fluid (water, liquid and gases) and increase its elevation. It is mostly used to supply fluid from low elevation to high elevation. A compressor is a device which is a mechanical device just like pump but it increases the potential energy of fluid by compressing it in a closed container.

The main difference between pump and compressor is that the pump is used to increase kinetic energy of fluid which further increases the elevation or pressure energy of it.  It moves the fluid from one place to another. But the compressor is mostly used to increase the potential energy (pressure energy) of fluid by pressuring it into a container. It is used to compress the fluid which increases its density and pressure. There are many other differences which are described below.

Difference between pump and compressor:

FILLET AND CHAMFER : WHY AND WHEN TO USE IT ??

Fillet is a round corner whereas chamfer is a slant face created at the corner. 

Even though both perform same function selection of chamfer or fillet depends on how the component is manufactured.We will discuss why and when they are used while creating parts in this article.

Comparison Between Chamfer and Fillet for External Edges :

Whether we choose to select a chamfer edge, or a fillet edge, it will often depend on factors of project such as budget and time constraints. The chart below compares some of these considerations:

When to use them ?

Fillets give a part better flow and less resistance. Using a fillet also eliminates any sharp edges that can be easily damaged, or that could cause injury when the part is handled. This means there is less risk of failing an inspection for having a burr or sharp edge. Fillets also have lower stress concentration factors, meaning that they distribute stress over a broader area. This makes filleted parts more durable, and able to withstand larger loads.

Chamfers are more forgiving when designing to fit mating parts, but overall it appears that designs using fillets are preferred by senior management, industrial designers and many others.

The main points that help in deciding to choose a fillet or chamfer are the following:

1.When done manually one of the main factors that come in deciding which to apply is the machining time. A chamfer requires less machining time that a fillet radius.

2.When done on CNC both chamfer and fillet require the same time as only a tool change is required.

3.For fillets different radii of tools has to be stocked to create different radii, but a single tool can be used for creating different chamfers.

4.Higher machining time required translates into cost. Thus chamfers are less costly compared to fillets.

5.Industrial designers tend to prefer fillets compared to chamfers as these are considered to be visually pleasing.

6.One of the other reasons is that protective coating like paint are more uniformly distributed over a fillet compared to chamfer. Thickness of coating is reduced on sharp corners of chamfers so coating is lost first on these spots. Fillets have no such issues due to uniform distribution of coating.

7.Since non uniform distribution of coating can lead to accelerated rusting this may be a disadvantage.

8.Fillet gives better stress flow (less resistance) compared to chamfers. Fillets generally give a lower stress concentration factor than chamfers .

9. Chamfers are more forgiving when fitting mating parts. i.e. even if there are inaccuracies in a chamfer mating parts might fit together. But if the radius of fillet changes it will be difficult to fit the mating parts.

IMPELLER Vs. PROPELLER !! DIFFERENCE EXPLAINED !!

Propellers and impellers both provide thrust, but do it in different ways.Let us understand the difference between two with the help of examples.

PROPELLER:

If you have ever seen pictures of ships closely, you must have noticed small rotating fans on both sides of the ship. 

These are propellers that actually help in propelling the ship forward. A propeller is an open running device that has the function of providing a thrust force. There is always a propelling fan on the mouth of an aircraft also. If we go by definitions given in various dictionaries, a propeller is a device having a revolving hub with rotating blades to propel an airplane, ship etc. 

A propeller is a special type of fan with blades that convert rotational motion into a force that helps in movement forward. This is because of a pressure difference that gets created between the front and the rear surfaces of the blades. This pressure difference pushes both air and water behind the blade. This thrust or force can be easily explained with the help of Newton’s laws of motion as well as Bernoulli’s theorem. Propellers are made heavy use of both in aviation as well as in ships.

IMPELLER:

Have you ever paid attention to the working behind the water pump that is used at home that sucks water from the main pipeline passing through the main road and brings it inside your home and then lifts it to the over head tank?

The working principle behind this pump is the impeller inside a casing that creates a sucking force that draws in liquid at a great force and diverts it to your overhead tank. An impeller is always inside a casing as its purpose is to draw the liquid inside as against a propeller that provides an outward thrust and is always open. An impeller, because of its rotation and especially designed blades, increases the pressure of the fluid and thus its flow. A centrifugal pump used to draw fluid is the best example of an impeller.

In brief:

Propeller vs Impeller

• Both propeller and impeller are specially designed blades with a motor.
• While a propeller is designed to covert rotational motion into forward thrust, an impeller is designed to use rotational motion to suck fluid in.
• A propeller has an open design while an impeller is always inside a casing or housing.