Glass Funnels

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The simplest design of feeding systems for liquid media are dropping funnels which are available with or without pressure equalising tube. Pressure equalising tubes are necessary, when different pressures occur or could occur in closed systems during the operation above or below the liquid to be fed. Should dropping funnels alternatively be used for vacuum, a design has to be chosen where the equalising tube is fitted with a single way or three way stopcock for locking. The space above the liquid must be open towards the atmosphere. Since many processes as e.g. continuously working distillations or kinetic analysis need a constant dropping frequency over a longer period of time and at pressure variations, dropping funnels must be employed. The adjustment of the required feed volume is effected with an interchangeable spindle valve, fitted below the funnel, or with an adjustable glass needle valve, adjustable from the top. Addition funnels are delivered either with pressure equalising line with single way or three way stopcock or with "Mariott"-tube. The "Mariott"-tube connects the space above the liquid to feed with the atmosphere. For operations under vacuum a design with an additional single way stopcock must be chosen. Some of these addition funnels are fitted with a silver coated high vacuum insulating jacket permitting the use in low temperature ranges. Some addition funnels have a suspended level bulb surrounding the original vessel. In this way, a pressure equalising is ensured when fluctuating hydrostatic pressures occur in the apparatus and the dropping speed keeps at a constant level until the vessel is completely drained.

dropping funnels
Dropping Funnels Normal or Vacuum Pressures
Design A: Without pressure equalising line is favourably used as feeding vessel. Dropping funnels with pressure equalising line (design B) can be employed when a slight overpressure arises during the vaporisation in the flask and a pressure equalising is necessary between the flask and the dropping funnel. For operation under vacuum, dropping funnels are used which are fitted with a single way (design A) or a three way (design B) stopcock in the pressure equalising line.

For Dropping Funnels




addition funnels with marriott tube
Addition Funnels with Marriott Tube
These funnels can be employed for operations under vacuum and under normal pressure. The introduction can be effected either with a spindle valve, adjustable at the top and interchangeable (Design A and B) or via a lateral located glass needle valve GNV 8(Design C and D). The pressure equalising is granted by the valve spindle which has an opening, or by the "Mariott"-tube with single way stopcock NS 3.

For Addition Funnels with Marriott Tube

Addition Funnels with Pressure Equalizing Line
These funnels can be employed both for operations under vacuum, normal pressure and slight overpressure, since they are fitted with a pressure equalising line with standard stopcock (PTFE key, bore 4 mm) and an additional pressure equalising standard stopcock (towards the atmosphere).

For Addition Funnels with Equalizing Line


Addition Funnels with Suspended Bulb
These funnels are suitable for operations under vacuum and normal pressure. The original feeding vessel is surrounded with a suspended level bulb. Since this bulb ensures the pressure equalising, these funnels can be used for operations where oscillating hydrostatic pressures occur.The addition funnels in design A and B have a glass needle valve spindle, adjustable at the top, in design C and D they have a lateral located glass needle valve GNV 8. Design B and D are additionally fitted with a tempering jacket. All of these funnels have a pressure equalising line.

For Addition Funnels with Suspended Bulb

Addition Funnels for Solids
This funnel permits the controlled introduction of dry and granular solids with an auger into a reaction vessel. The integrated pressure equalising line, lockable with an PTFE spindle valve, allows an operation both under vacuum and inert gas. The use of threaded connections guarantee an excellent tightness also under vacuum operation and avoids contact with grease.

For Addition Funnels For Solids

separating funnelsSeparating Funnels
Separating funnels are manufactured according to DIN 12 451 and preferably used for discontinuous shaking out of solvents. Capacity NS Stopcock

For Separating Funnels