A funnel is a tube or pipe that is wide at the top and narrow at the bottom, used to guide liquids or powders into small openings. Funnels are commonly made of stainless steel, aluminum, glass, or plastic. There are several types of specialized funnels including filter funnels for separating solids from liquids, powder funnels for transferring powders, and separatory funnels for separating mixtures into immiscible solvent phases. Other types include Büchner funnels for vacuum filtration, dropping funnels for slow reagent addition, and eco funnels designed to reduce chemical contamination.

1. Funnel
Barreto Selwyn

2. Introduction
– A funnel is a tube or pipe that is wide at the top and narrow at
the bottom, used for guiding liquid or powder into a small
opening.
– The material used in its construction should be sturdy enough
to withstand the weight of the substance being transferred, and
it should not react with the substance.
– It is used to channel liquid or fine-grained substances into
containers with a small opening

3. Material used
– Funnels are usually made of stainless steel, aluminium, glass, or
plastic.

4. Types of Funnels
– Plain Funnel
– Filter funnel
– Powder Funnel
– Separatory Funnel
– Hirsch funnel
– Büchner funnel
– Tullgren funnel
– Dropping funnel
– Hot filtration funnel
– Eco funnel

5. Plain Funnel
– Exist in various dimensions, with longer or shorter necks.
– Designed with a 60 Deg bowl angle to ensure precise fitting of
the filter paper
– High thermal shock resistance and chemical resistance
– Generally used for filtering and decanting liquids of varied
densities

7. Filter funnel
– A filter funnel is a laboratory funnel used for separating solids
from liquids via the laboratory process of filtering.
– In order to achieve this, a cone-like shaped piece of filter paper
is usually folded into a cone and placed within the funnel.
– The suspension of solid and liquid is then poured through the
funnel.
– The solid particles are too large to pass through the filter paper
and are left on the paper,

9. Powder Funnel
– Ideal for transferring powders
– Designed with a short wide stem to facilitate smooth flow

11. Separatory funnel
– A separatory funnel, is a piece of laboratory glassware used in liquid-
liquid extractions to separate the components of a mixture into two
immiscible solvent phases of different densities.
– Typically, one of the phases will be aqueous, and the other a lipophilic
organic solvent such as ether, MTBE, dichloromethane, chloroform, or
ethyl acetate. All of these solvents form a clear delineation between
the two liquids.
– The more dense liquid, typically the aqueous phase unless the organic
phase is halogenated, sinks and can be drained out through a valve
away from the less dense liquid, which remains in the separatory
funnel.

13. Hirsch funnel
– Hirsch funnels are essentially smaller Büchner funnels and
primarily used to collect a desired solid from a relatively small
volume of liquid (1-10 mL).
– The main difference is that the plate is much smaller, while the
walls of the funnel angle outward instead of being vertical.

15. Büchner funnel
– Büchner funnel is one device used for pressure assisted
filtration. Buchner funnel is a cylindrical porcelain filtering
funnel (glass and plastic funnels are also available) that has a
perforated plate on which the flat filter paper is placed.
– A vacuum in the flask underneath the filter allows atmospheric
pressure on the sample to force the liquid through the filter
paper

18. Tullgren funnel
– A Tullgren funnel, is an apparatus used to extract living
organisms, particularly arthropods, from samples of soil.
– The Tullgren funnel works by creating a temperature gradient
over the sample such that mobile organisms will move away
from the higher temperatures and fall into a collecting vessel,
where they perish and are preserved for examination.

20. Dropping funnel
– A dropping funnel is a type of laboratory glassware used to
transfer fluids. They are fitted with a stopcock which allows the
flow to be controlled.
– Dropping funnels are useful for adding reagents slowly, i.e.
drop-wise. This may be desirable when the quick addition of the
reagent may result in side reactions, or if the reaction is too
vigorous.

22. Hot filtration funnel
– is a less commonly seen funnel where the funnel is jacketed,
and surrounded by a heated fluid.

24. Eco funnel
– is equipped with a latching lid and gasket to reduce chemical
contamination and conform to OSHA and EPA regulations.
– OSHA—Occupational Safety & Health Administration
– EPA-- Environmental Protection Agency