DE2932578C2 - Gas injection valve for suspensions - Google Patents

Description

1. the injection pipe (3) at a distance of 2 to 10 times The diameter of the discharge side is angled less than 30-90 °,

2. the hollow piston (2) can be moved by means of the threaded spindle (5) and on the gas supply side is guided in a soft material ring (4) opposite the injection pipe (3),

3. the hollow piston (2) is closed on the exhaust side by a plate (1), the plate has an annular cutting edge which is directed in the direction of the injection pipe and which presses against the end face of the injection pipe (3) acts as a seal and

4. the flat cylinder surface has bores on the gas-feeding side, according to patent 28 52 536,

characterized in that additionally between the plate (1) and the end face of the injection pipe (3) at least one soft material and / or soft metal throttle ring (6) on the plate (1) and / or on the end face of the injection pipe (3) arranged in this way is that when the valve is closed he (she) is in the space between that of the cutting edge of the Plate (1) and the face of the injection pipe (3) formed seal and the hollow piston (2) is located ^) and that he (she) has such a strength in the direction of movement of the hollow piston (2) that the cutting edge of the plate (1) with the valve closed with 50 to 80% of the total closing force on the sealing surface of the injection pipe (3) is pressed and accordingly 20 to 50% of this total closing force be absorbed by the throttle ring (s) (6).

For the gassing of PVC suspensions is usually a bottom valve that is as level as possible with the Is to close the inner surface of the container, blow gas or water vapor into the degassing container from below. As a rule, these degassing processes are batch operations, which is why the gas injection valve is used must be closed again in the filled container. For reasons of purity it must be excluded be that during Her injection and especially during the closing process solids in the gas line and the valve penetrates.

The object of the invention is therefore to easily specify an injection valve which has no “dead” spaces can be regulated, the incoming gas flow is evenly and finely distributed and a flow back into the Gusleitung reliably prevented by the absolute tightness of the closed valve even with prolonged use is ensured without this having to be constantly monitored or regularly replacing the sealant

must become.

This task is solved by the gas injection valve for suspensions with an injection pipe (3) which is perpendicular to the inside of the boiler and which is connected to it Kelter gas supply and a movable hollow piston (2) in the injection pipe, which is sealed by ring seals closed at the front and curved on the Cylinder surface is pierced many times, wherein

1. the injection pipe (3) at a distance of 2 to 10 times The diameter of the discharge side is angled less than 30-90 °,

2. the hollow piston (2) can be moved by means of the threaded spindle (5) and gets on the gas supply side is guided in a soft material ring (4) opposite the injection pipe (3),

3. the hollow piston (2) on the exhaust side through a The plate (1) is closed, the plate being an annular one directed in the direction of the injection pipe Has cutting edge which acts as a seal against the end face of the injection pipe (3) and

4. the flat cylinder surface has bores on the gas-feeding side, according to patent 28 52 536.

It has now proven advantageous in various ways to use this gas injection valve referred to above to change that between the plate (1) and the face of the injection pipe (3) additionally at least one soft material and / or soft metal throttle ring (6) on the plate

(1) and / or on the end face of the injection pipe (3) is arranged in such a way that it (they) is when closed Valve in the space between the edge of the plate (1) and the face of the injection pipe (3) formed seal and the hollow piston (2) is (s) and that he (she) has such a strength in the direction the movement of the hollow piston (2) has (s) that the cutting edge of the plate (1) when the valve is closed is pressed against the sealing surface of the injection pipe (3) with 50 to 80% of the total closing force and accordingly 20 to 50% of this total closing force can be absorbed by the throttle ring (s) (6).

The advantages and properties mentioned in the main patent 28 52 536 and possible applications also meet in full for the modified according to the invention Valve closed.

The construction of the valve according to the invention also differs from the construction in the main patent 28 52 536 described gas injection valve only through the soft material and / or soft metal throttle ring (s) (6), the (those) attached to the plate (1) between the cutting edge of the plate (1) and the hollow piston (2) and / or on the part of the end face of the injection pipe (3) between that of the cutting edge of the plate (1) and said End face formed sealing ring and from the inside and said end face of the injection pipe (3) formed edge can be attached.

Because of the simpler and generally less sensitive construction, it is generally preferred to use it on the plate (1) to attach a throttle ring (6) between the cutting edge and the hollow piston (2).

Under attached or attached is also understood here that parts of the throttle ring in the part on which it is attached or attached, can be embedded.

According to the invention, such substances can be used as soft material and / or soft metal throttle rings, compared to the materials from which the valve is made, in particular compared to the

Materials of the plate (1) and the injection pipe (3) have a lower hardness, as far as they are suitable for the respective Application have the necessary temperature stability. As soft material throttle rings can be used are z. B. Rings made of optionally foamed plastics, in particular copolymers of ethylene and fluoro-hydrocarbon polymers, preferably Ethylene-propylene copolymer or polytetrafluoroethylene (PTFE), rings made of mineral (e.g. Asbestos) or textile fibers, which are also compatible with the above ίο called plastics can be impregnated or coated. Soft metal rings can also be used be e.g. B. made of aluminum, tin, lead, iron, copper, Silver, gold, alloys of these metals e.g. B. also with zinc, magnesium or mercury. Because of their bigger ones Plastic rings are generally preferred for elasticity.

A suitable embodiment is shown in FIG. a shown as a vertical section Fig.b shows a pure horizontal section through the hollow piston 2 in the plane indicated by BB.

The mode of operation of the throttle ring (s) (6) can be described as follows, without this resulting in a Limitation of the mode of action is intended:

The cutting edge of the plate (1) and the ground face of the injection pipe (3) are effective when it is closed Valve generally as the only sealing element seen in the direction of the gas or water vapor blown in, According to the invention, at least one soft material and / or soft metal ring can be connected upstream of the cutting edge which serves as a throttle section (s) and thus an exact setting of the required Makes closing force possible.

By arranging the throttle ring (s) between Sealing element and hollow piston are achieved so that when the valve is closed, a "nozzle effect" is achieved which has the effect that the valve is largely blown free of dispersion particles.

1 sheet of drawings

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Claims (1)

Claim: Gas injection valve for suspensions with an injection pipe that is perpendicular to the inside of the boiler (3) with an angled gas supply and a hollow piston (2) that can be moved in the injection pipe, which is sealed by ring seals, closed at the end and on the curved cylinder surface is pierced many times, with