JPS61188111A - Device for mixing and pressure-keeping reaction resin compound - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed description of the invention [Industrial field of application] The invention comprises a once-through mixer and a force recovery device arranged downstream in the direction of the conveying flow and consisting of a cylinder and a piston movable relative to this cylinder. The present invention relates to a device for mixing a reactive resin compound and keeping the pressure constant.

BACKGROUND OF THE INVENTION Reactive resin compounds are produced by mixing precisely defined amounts of resin and hardener, often also using multiple resins and multiple hardeners. Additionally, auxiliary materials such as fillers, colorants, adhesion promoters, accelerators, etc. can also be distributed in the resin and hardener components. In the automatic production of such a reactive resin compound, for example consisting of a resin component and a curing agent component, using a reciprocating or rotary positive displacement pump and a static or dynamic once-through mixer, It is often necessary to form a stream of reactive resin compound continuously and/or to maintain it at a defined pressure. This is particularly the case when the reactive resin compound is poured into a closed mold immediately after the mixing of the two urine components and is cured or gelled under pressure. This also applies when the once-through mixer of such a resin processing installation is combined with a multiple dosing device. This is because, for the correct functioning of the dosing device, a buffer material with a defined pressure is required. Problems arise particularly when using highly reactive resin compounds with a usable time of less than 1 hour and/or with reactive resin compounds containing rapidly settling fillers. In this case it is necessary to keep the residence time of the reactive resin compound in the installation extremely short and to avoid build-up of the reactive resin compound and/or filler.

German Patent Application No. 27 41 3 050 discloses that static or dynamic once-through mixers are equipped with so-called pressure recovery for compensation of pulsations and for maintaining constant pressure during the automatic processing of reactive resin compounds. It is known to post-connect devices. However, the use of such a pressure recovery device consisting of a cylinder and a movable piston results in a relatively long residence time of the reactive resin compound in the pipe or an additional pressure loss in the compound stream. Particularly in the case of highly reactive resin compounds, a rapidly hardened resin layer forms on the wall soil, which results in a corresponding reduction in the cross-sectional area; the elimination of such a reduction requires frequent interruptions in operation. This requires a large amount of maintenance and cleaning costs.

[Problems to be Solved by the Invention] The present invention provides a gate, a device for mixing the reactive resin compound and a device for maintaining a constant pressure so as to avoid at least most of the occurrence of reduction in cross-sectional area due to deposition of the reactive resin compound and/or filler. The purpose is to provide

[Means for Solving the Problems] This object is based on the present invention and includes a once-through mixer integrated into the piston, the outlet hole of this mixer opening directly into the cylinder. This is achieved by

[Operations and Effects of the Invention] - The present invention incorporates a once-through mixer in the piston of the pressure recovery device so that the reaction resin compound that has just been prepared in the mixer is directly transferred into the cylinder of the pressure recovery device. This is based on the knowledge that the reactive resin compound that is reached and that was initially fed into the cylinder is the first to be discharged again. The entire device thus operates in direct flow-through fashion, the residence time of the reactive resin compound being limited to a minimum value and the risk of deposition of the reactive resin compound and/or filler being at least largely avoided. Another advantage of the device according to the invention is that subsequent devices, such as, for example, multiple dosing devices, closed molds or injection valves, can be connected directly to the cylinder of the pressure recovery device, thus obtaining very short connections. It is in. This is particularly important when considering the necessary short residence time of the already activated resin compound in the installation.

According to an embodiment of the invention, a static mixer is integrated into the piston. Since such a static mixer does not require a rotating mixer, the integration of the pressure recovery device into the movable piston is particularly simple. In particular, static mixers can then be constructed with minimal outlay by mixing elements that are fitted into the axial bore of the piston.

The risk of deposits on the bottom of the piston of the pressure recovery device can be avoided if a first flow guiding device, which is spaced apart from the bottom of the piston after the mouth hole of the mixer in the direction of the conveying flow, is fixed. By doing so, it can be further reduced. The risk of deposits on the bottom of the cylinder is likewise eliminated by the fact that in the direction of the conveying flow, in front of the outlet hole of the cylinder, a second flow guiding device is fixed, which is arranged at a distance from the bottom of the cylinder. Accordingly, it can be reduced even further. By using such a flow guiding device, the direction of the conveying flow can be changed so that, at least in the case of approximately the same flow velocity, the flow velocity is increased and, in particular, flow stagnation is avoided in a range that is dangerous for deposition.

This can be realized particularly easily if the flow guide device is of disc-shaped design. Furthermore, if we consider the optimization of flow conditions.

It has proven particularly advantageous for the flow guiding device to be provided with a central hole allocated for passing a portion of the conveying stream.

[Embodiment] Next, the present invention will be described in detail with reference to drawings showing an embodiment of the apparatus based on the present invention.

The drawing shows a simplified device for mixing the reaction resin compound and keeping the pressure constant.
The cylinder Z of the pressure recovery device is denoted by the code N in the direction of the conveying flow shown in the static once-through mixer and the whole by the code N.
A stationary mixer D installed in the movable piston of the pressure recovery device N,
It is formed by a plurality of mixing elements M fitted into axial bores B in the piston. After the outlet hole AI of the static once-through mixer, which is narrower than the axial hole B when viewed in the direction of the conveying flow F, a first flow is arranged at a distance from the bottom of the piston. A guide device St is fixed, and a center hole Ll is provided in this flow guide device.
The bottom plate of the first flow guiding device S1 having a disk shape is fixed to the piston using a plurality of small Bels whose cross-sectional shape is favorable to the flow. A spacing is defined between the bottom of the piston and the first flow guide device S1. A second flow guide device S2 is fixed in front of the outlet hole A2 of the cylinder Z when viewed in the direction of the conveying flow F, and is arranged at a distance from the bottom of the cylinder Z. A center hole L2 is provided inside.

The fixing of the second flow guiding device S2, which likewise has the shape of a disk, on the bottom of the cylinder Z takes place here also using a number of small pieces whose cross-sectional shape is advantageous for the flow. At the same time, the spacing between the bottom of the cylinder Z and the second flow guiding device S2 is determined via a small piece marked Be2.

When employing the device in a casting resin processing facility, the resin and hardener components are synchronized in the mixer in the correct mixing ratio by means of a force-actuated positive displacement metering device. A static once-through mixer is supplied with a flow through the static mixer. Since the static once-through mixer is integrated into the movable piston of the pressure recovery device N, the connection to the fixedly arranged positive displacement metering device is via a flexible pipe, e.g. This is done through a flexible hose made of rubber. During flow through the static mixer, the mixing element M performs multiple divisions and superimpositions of the collected component streams, so that the homogeneous mixture of the reactive resin compound passes through the outlet hole AI into the cylinder of the pressure recovery device N. Reach inside Z.

A portion of the reactive resin compound sent out from the outlet hole AI is 1. The central hole L1 of the first flow guide device 31 is moved in the direction of the axis of symmetry Sa of the entire device without changing direction.
flow through the piston, while the other part flows in all directions radially outward along the bottom of the piston and formed between the inner wall of the cylinder Z and the outer circumference of the first flow guide S1. The direction is changed in the axial direction through a ring-shaped gap.

Such guidance of the carrier stream F ensures that a bottom-to-top build-up of reactive resin compound and/or filler on the piston is avoided. When flowing out from the cylinder Z, a part of the one-reacted resin compound moves along the axis of symmetry Sa without changing direction.
passing through the center hole L2 of the second flow guide device S2 in the direction of
The other part of the zero-reactive resin compound flowing through the outlet hole A2 of the cylinder Z is axially connected to the inner wall of the cylinder Z and the second
flows through a ring-shaped gap formed between the outer periphery of the flow guide device S2 and radially inwardly along the bottom of the cylinder Z. The liquid flows in the direction of the flow, and flows into the outlet hole A2 whose inlet is widened into a truncated conical shape. Such guidance of the carrier stream F ensures that no buildup of reactive resin compound and/or filler on the bottom of the cylinder Z is avoided. The reactive resin compound then passes directly through the outlet hole A2 into a subsequent device, such as, for example, a multiple metering device, a closed mold or an injection valve.

Suitable materials for the construction of the illustrated device are metals or plastics, such as those commonly used in the processing of reactive resin compounds. In particular stainless steel is used. A not-shown sealing collar made of plastic is provided for sealing the piston against the inner wall of the cylinder Z, and this sealing collar is advantageously designed as a lip seal. Behind the guide part with this sealing collar, the piston has a relatively small diameter section, which is intended in particular to eliminate sticking and straining of the piston in the cylinder Z.

A force indicated by the arrow P can be applied to the piston K in the axial direction, and this force can be applied, for example, by a pneumatic or hydraulic actuator.

By appropriate control of this force P, the pressure recovery device N can dampen the pulsations of the conveying stream F of the treatment plant and serve as a reserve and pressure holder for the downstream equipment connected to the cylinder Z.

However, it is also possible to have a fixed arrangement of the piston K incorporating a flow-through mixer and to exert a force P on the cylinder Z. In this case, a flexible connecting line to a corresponding fixedly arranged downstream device is connected to the outlet hole A2 of the cylinder Z.

[Brief explanation of drawings]

The drawing is a longitudinal sectional view of an embodiment of the device according to the invention. At... Outlet hole of the mixer, A2... Outlet hole of the cylinder, B... Axial hole, D... Once-through mixer,
F... Conveyance flow, K... Piston, L1, L
2...Temple center hole, M...-mixed element, 31-...
first flow guide device, 52--second flow guide device;
Z fist... cylinder.

Claims (1)

Claims: 1) Mixing and constant pressure of a reactive resin compound with a once-through mixer and a pressure recovery device arranged downstream in the direction of the conveying flow and consisting of a cylinder and a piston movable relative to this cylinder. A device for holding, comprising a once-through mixer (D) integrated in the piston (K),
A device for mixing reactive resin compounds and maintaining a constant pressure, characterized in that the outlet hole (A1) of this mixer opens directly into the cylinder (Z). 2) Claim 1, characterized in that a static once-through mixer (D) is incorporated in the piston (K).
Apparatus described in section. 3) A mixing element (with a static once-through mixer (D) fitted into an axial bore (B) of a piston (K))
3. The device according to claim 2, characterized in that it is constituted by M). 4) After the outlet hole (A1) of the once-through mixer (D) in the direction of the conveying flow (F), a first flow guiding device (S1) is arranged at a distance from the bottom of the piston (K). 4. Device according to claim 1, characterized in that it is fixed. 5) A second flow guide device (S2) is fixed in front of the outlet hole (A2) of the cylinder (Z) in the direction of the conveying flow (F) and is arranged at a distance from the bottom of the cylinder (Z). The device according to any one of claims 1 to 4, characterized in that: 6) The device according to claim 4 or 5, characterized in that the flow guide devices (S1, S2) are formed in the shape of a disc. 7) In the flow guide device (S1, S2), the conveying flow (F)
The central hole (L1, L2
) The device according to any one of claims 4 to 6, characterized in that the device is provided with: