A hand pump is a most common type of positive displacement pump. A hand pump operates by a human to transfer fluid or air from one place to another. It is also called a manually operated pump. In various industrial, marine, irrigation, and recreational activities in all countries, hand pumps are widely used. There are several types of hand pumps, which work mainly on the principle of rotation of pistons, diaphragm, or blades, and have a return valve at the inlet and outlet of the chamber. Most pumps are reciprocating pumps or plunger pumps, and positive displacement pumps.
In short, a hand water pump is a mechanical device or pump that uses human energy to draw water from a well. These are the most basic types of pumps that have been used since ancient times and have been used ever since. It is still very common in Indian and Pakistan villages.
The hand pump is truly the gospel of humanity. They offer cost-effective pumping solutions for remote areas. Many types of hand pumps are used, most of which have similarities in design and principle. The main components of a hand pump include the handle, pump rod, piston, piston valve, lift, suction lift, and water outlet.
Types of Hand Pump
1) Suction and lift hand pump
Suction and lifting are important considerations when pumping liquids. The vertical distance between the pumped fluid and the center of the pump is called suction, and the vertical distance between the pump and the discharge point is called the head. The working depth is less than 7 meters, and the suction depth of the hand pump is limited by atmospheric pressure.
The pump and the ability of the operator to lift the weight on the power line are factors on which the height of the hand lifting pump depends. Therefore, both the pump and the operator will be able to use smaller diameter tubing for a further increase over using larger diameter tubing.
In addition to using shallow groundwater to supply water, another version of the hand suction pump was developed in the late 19th century. Smaller vessels and offshore pumps as contractors on construction sites.
2) Force Pump
In cases where it is necessary to raise the water to a height (about 7 m), where the suction or lifting pump can work effectively, or where the pressure is so high that it comes out of the nozzle with excessive force. In its manual form, the force hand pump relies on the operator to pump the handle like the suction pump. The difference, however, is that after the water is drawn in through the lower valve (due to the lifting of the piston connected to the handle), its exit occurs through a tube or mouthpiece near the main cylinder. When the water is drawn over the bottom valve and trapped there, when the piston or plunger is pressed again on the next stroke, the water flows to the outlet.
3) Siphon Hand Pump
The simplest siphon (or siphon) is a curved tube, one end of which is used to move through the water, and the other end is placed in a container to receive the water. The supply container must be greater than the receiving container. Water always tries to find its lowest level.
A very simple pump with plastic or rubber balls and flap valves on both sides is used to drain the fuel tank or water tank into the fuel tank using this principle. The liquid flows effortlessly from the upper to the lower container when the pump is full. The diaphragm pumps work very well in this regard when the hand pumps allow liquid to flow through them in the direction of flow. A large amount of liquid, such as a swimming pool, can be drained effortlessly without consuming expensive energy if the liquid level is correct.
Hand pump working
There are many types of hand water pumps. The most common hand pump is a positive displacement pump with a reciprocating piston or plungers. In a reciprocating pump, the piston has a piston valve (check valve) and flows vertically into a cylinder equipped with a valve at the bottom (check valve).
By applying force to the water pump handle, the pump rod connected to the piston moves vertically.
As the pump piston moves up, the piston valve closes, and a vacuum is created under the piston valve. The piston valve transfers water to the cylinder through the lower valve and opens the lower valve.
At the same time, the piston water is blocked by the closed piston valve and moves upwards. In a hand suction pump, water flows through the water outlet. In a hand pump with a piston-cylinder, it is forced to rise to the main pipe.
As the piston moves down the hand pump, the lower valve closes to prevent water flow, and the piston valve opens so that the piston can go down through the water into the cylinder
Source@techsaa: Read more at: Technology Week Blog