PASCAL'S SYRINGE: CHARACTERISTICS AND USES - CHEMISTRY - 2024

The syringe Pascal is an indeformable circular container with several holes in its surface and a plunger piston. Each of these holes is covered with wax or any other material.

By filling the syringe with water and depressing the plunger, the pressure is transferred to all the liquid and the fluid exits through the ports. The fluid comes out with a force that is directly proportional to the pressure exerted (lower image, with water as the fluid).

Source: Gabriel Bolívar

It is used as an instrument in laboratories to check Pascal's principle. The syringe and the physical principle bear the same name as their creator: the French scientist, philosopher and religious Blaise Pascal. With it he demonstrated Pascal's principle, also known as Pascal's law. Pascal also created the hydraulic press, based on his own principle.

Pascal's syringe is used to check the operation of some hydraulic machines. It is also useful in the studies of the dynamics and mechanics of fluids.

The foundation of the function of the syringe is used in the construction of hydraulic systems, and in heavy machinery such as hydraulic excavators; in aeronautics, in the landing gear, and also in pneumatic systems.

characteristics

Pascal's syringe is a simple pump that has the following characteristics in its structure:

-The body of the syringe is made of a non-deformable, non-flexible material that resists pressure.

-The surface of the container or body of the syringe is globular in shape, has holes of equal size, uniformly distributed.

-In the beginning, the syringe was globular, round or spherical. Subsequently tubular syringes have been created.

-These holes or gaps must be partially or temporarily plugged or closed before filling the container with a fluid.

-The material that closes these perforations must be easy to remove when pressure is exerted on the liquid inside.

-The syringe has a plunger or piston that fits perfectly into the structure of the syringe body.

-Pushing the plunger of this instrument exerts pressure on the fluid contained in the syringe.

-Within the syringe the fluid must be in equilibrium or at rest. But once pressure is applied with the piston, the liquid or gas comes out of the holes with equal pressure.

Pascal's Syringe Basics

Pascal's syringe was created with the characteristics described in the previous section. The syringe works by fulfilling Pascal's principle. This principle explains how the pressure exerted on a static or incompressible fluid contained in a container is disseminated.

Pascal's syringe is a container with non-deformable walls of a circular, globular or round shape. This syringe and the tubular versions contain or confine the fluid, liquid or gas, which is in equilibrium.

By applying pressure to the plunger or piston of the syringe, the pressure is immediately transferred to the fluid it contains. The fluid driven by the force exerted on the piston, tends to come out with the same pressure through the orifices of the syringe.

The force is transmitted within the fluid, which can be liquid like oil or water, or gaseous in nature. A small piston has been found to generate a proportional force or pressure; and a large piston generates a large force.

Most hydraulic systems use incompressible fluid in hydraulic cylinders with the same foundation as Pascal's syringe.

Pascal's principle

But what is Pascal's principle or Pascal's law? It is a scientific principle from the area of ​​physics. It shows that all the pressure to which a confined fluid is subjected is spread throughout it evenly.

The principle states that there is no pressure loss. This pressure reaches or is transmitted with equal intensity both to the fluid and to the walls of the container.

The container corresponds to a system that contains the fluid (liquid or gas), which is initially in a state of equilibrium.

The applied pressure is transmitted or transferred with the same intensity at all points and in all directions of the fluid. This principle is fulfilled regardless of the area in which the pressure is applied to the fluid that is confined.

There is uniform energy transfer in the system. That is to say, all the pressure to which a fluid is subjected is spread in it uniformly.

Pascal's law or principle constitutes the foundation of the operation of hydraulic systems. These systems take advantage of the fact that the pressure is the same in all directions. The pressure per area will be the force that the fluid will give to the surroundings of the system.

Applications

Pascal's syringe is used in laboratories to demonstrate Pascal's principle or law. This is checked in the teaching and research laboratories; for example, that of fluid mechanics.

Hydraulic syringes

Pascal's syringe has been a model or source of inspiration for the creation of other similar laboratory instruments.

Tubular, plastic, metal hydraulic syringes are designed with different characteristics. Likewise, models have been made that have syringes with different cross-sectional diameters, with pistons or plungers that vary in size.

Hydraulic systems

There are prototypes of hydraulic system simulators to evaluate fluid displacement, applied force and generated pressure, among other variables.

A variety of hydraulic mechanical systems work on the principle of the syringe and Pascal's law. In the braking and landing gear of aircraft, tires, hydraulic vehicle lifters, among other systems.

Hydraulic excavators

In order to improve the design of hydraulic excavators, prototypes based on the syringe and Pascal's principle are made.

Analyzes of the functions of excavators used to excavate below the ground are made. It is specifically experimented with to optimize the performance of the hydraulic system axes, among other things.

References

1. Jerphagnon, L. and Orcibal, J. (2018). Blaise Pascal. Encyclopædia Britannica. Recovered from: britannica.com
2. The Editors of Encyclopaedia Britannica. (July 20, 2018). Pascal's Principle. Encyclopædia Britannica. Recovered from: britannica.com
3. Hodanbosi, C. (1996). Pascal's Principle and Hydraulics. National Aeronautics and Space Administration. Recovered from: grc.nasa.gov
4. Kuhl. B. (2014). Proving Pascal's Principle With Syringe Hydraulics.
5. Scienceguyorg Ramblings. Recovered from: scienceguyorg.blogspot.com
6. Gerbis N. (2018). What were the famous Blaise Pascal inventions? HowStuffWorks. Recovered from: science.howstuffworks.com
7. Nave R. (2016). Pascal's Principle. Recovered from: hyperphysics.phy-astr.gsu.edu