PUMP AND PRIMING
the process of exhausting air from the pump and hard section hose ,thus allowing water pushed by the wight of the atmosphere (atomic pressure) to fill the void is called priming.
- WHAT IS PUMP
- WHAT IS PRIMING
the process of exhausting air from the pump and hard section hose ,thus allowing water pushed by the wight of the atmosphere (atomic pressure) to fill the void is called priming.
TYPES OF PRIMER
- RECIPROCATING PRIMING
- WATER RING PRIMING
- EXHAUST EJECTOR PRIMING
- POSITIVE AND NEGATIVE PRIMING
the primer consist of small piston which is driven by an eccentric cam on the main pump driven shaft.
steps in priming process-
- Induction stroke - a vacuum is created in the priming valve.atmospheric pressure caused, the atomic priming valve and air is dawn , by piston through inlet flap valves from the suction tube
- Exhaust stroke - air in primer is forced out through the exhaust flap valve to atmosphere . once pump pressure is generated it is communicated to the back of the piston which lifts off the cam so that the primer effectively discharges.
WATER RING PRIMING
A water ring primer is a form of positive displacement pump. the principle of operation is also very simple.
a vaned impeller with a hollow centre rotates in an elliptical housing around a stationary hollow boss which a projection from housing and cover. which communicates with the primer suction and delivery connection.
EXHAUST EJECTOR PRIMING
The devices used to exhaust air from the suction and the casing is known as priming devices. After the pump is primed the atmospheric pressure is able to force the water to reach the pump entry.
There are different types of primers which are listed below:
Reciprocating primer:
These are reciprocating pumps which develop higher pressure by the direct action of the plunger on the fluid (liquid or gas) confined in a cylinder and forcing the fluid out from the discharge.
POSITIVE AND NEGATIVE PRIMING
The terms positive and negative priming refer to when priming affects the speed of processing. A positive prime speeds up processing, while a negative prime lowers the speed to slower than un-primed levels. Positive priming is caused by simply experiencing the stimulus, while negative priming is caused by experiencing the stimulus, and then ignoring it. Positive priming effects happen even if the prime is not consciously seen.The effects of positive and negative priming are visible in event related potential readings.
Positive priming is thought to be caused by spreading activation.This means that the first stimulus activates parts of a particular representation just before carrying out an action or task. The representation is already partially activated when the second stimulus is encountered, so less additional activation is needed for one to become consciously aware of it.
Negative priming is more difficult to explain. Many models have been hypothesized, but currently the most widely accepted are the distractor inhibition and episodic retrieval models. In the distractor inhibition model, the activation of ignored stimuli is inhibited by the brain.The episodic retrieval model hypothesizes that ignored items are flagged 'do-not-respond' by the brain. Later, when the brain acts to retrieve this information, the tag causes a conflict. The time taken to resolve this conflict causes negative priming Although both models are still valid, recent scientific research has led scientists to lean away from the distractor inhibitor model.
PUMPS
there are many types of pumps are available
- centrifugal pump
- exhaust gas ejector pump
- positive displacment pump - types
- force pump
- lift pump
- plunger pump
- rotery pump
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