What is vacuum pressure impregnation?
Vacuum Pressure Impregnation (V.P.I) is a process by which a fully wound electric apparatus stator or rotor is completely submerged in a Resin. Through a combination of dry and wet vacuum and pressure cycles, the resin is assimilated throughout the insulation system.
What are the types of impregnation?
The impregnation process type is defined by the first step, which will largely determine if the castings are sealed….Armed with this understanding, the three commercially viable impregnation process types are:
- Dry Vacuum and Pressure (DVP)
- Dry Vacuum (DV)
- Wet Vacuum (WV)
What are the two advantages of vacuum impregnation?
The process has the advantages of providing a void free system with high dielectric strength, mechanical resilience, chemical and moisture resistance, and good thermal capabilities. The disadvantages of high cost and large tank size requirements are noted.
What is impregnation process?
Impregnation is the classic and the simplest procedure to load a given porous support with the metal component in the solid-state way (physical mixture of both component in solid state) or more commonly via wet impregnation (physical mixture of the support in solid state and the metal component dissolved in a liquid …
Why is VPI done?
VPI is often preferred over the traditional methods of insulating electric motors for four distinct reasons: Better electric motor performance in harsh environments. Improved electric motor efficiency made possible by better heat transfer. Improved mechanical winding design.
What is global VPI?
Global Vacuum Pressure Impregnation (VPI) is a process in which ‘green’ coils are placed in a stator, then the whole stator is processed. The process involves a heated stator being placed in a ‘dry’ tank and a vacuum (as close to pure vacuum as possible) being applied for a designated period of time.
What is the advantages of impregnation?
Advantages of Impregnation
| ADVANTAGE | TARGET MATERIAL |
|---|---|
| Improving mechanical, toughness and strength, degradation-proof | powder metal, sintered metal, sprayed ceramics, plastic magnets and others |
| Improving machinability | powdered metal, sintered metal, sporayed ceramics, plastic magnets and others |
What is vacuum impregnation in histopathology?
Vacuum embedding involves the wax impregnation under negative atmospheric pressure inside an embedding oven to hasten removal of air bubbles and clearing agent from the tissue block thereby promoting a more rapid wax penetration of tissue.
What is the purpose of impregnation?
Impregnation (infiltration) is the process whereby the clearing agent is completely removed from the tissue and replaced by a medium that will completely fill all the tissue cavities thereby giving a firm consistency to the specimen, and allowing easier handling and cutting of suitably thin sections without any damage …
What is impregnation process Mcq?
Explanation: Impregnation is the process of porosity sealing of sintered components. Impregnation of the sintered component is done using either a lubricant or a resin, the purpose is different in each case. 2.
What is the importance of impregnation?
The main advantage of the impregnation method is that it is easy to control the amount of the drug that is loaded in the carrier. Furthermore, the drug is efficiently loaded and the method is, therefore, suitable for expensive payload molecules.
What are the types of Microtomes?
There are different types of microtomes:
- hand microtome.
- rotational microtome.
- sledge microtome.
- cryostat (freezing microtome)
- ultramicrotome.
What are the advantages and disadvantages of vacuum embedding?
It has advantages that it has no drastic effect on the tissue, it penetrates the tissue rapidly and does not make the tissue brittle. Disadvantages: The most important disadvantage is that, it is toxic, hygroscopic and causes shrinkage of the tissue. Its use requires carefully controlled conditions.
What is vacuum impregnation process?
Vacuum impregnation, also known as porous metal sealing or porosity sealing, is a process used to seal porosity in metal castings via the application of vacuum pressure. Vacuum impregnation can be effective in eliminating micro porosity and macro porosity.
What is vacuum embedding?
What is the advantage of impregnation?
What is impregnation and embedding?
Impregnation is the process of complete removal of clearing reagents by substitution of paraffin or any such similar media such as beeswax. After complete impregnation with a suitable medium, solid block of suitable medium containing impregnated tissue is obtained by a process called embedding.
How do microtomes work?
The vibrating microtome operates by cutting using a vibrating blade, allowing the resultant cut to be made with less pressure than would be required for a stationary blade. The vibrating microtome is usually used for difficult biological samples.
What are microtomes used for?
Microtomes are used to cut thin slices of material, known as sections. Microtomes are used in microscopy, allowing for the preparation of samples for observation under transmitted light or electron radiation.