DE2749134A1 - METHOD AND DEVICE FOR LIQUID LEAK MONITORING FOR THE PRODUCTION OF FOUNDRY MOLD IN CONTINUOUS SCREW MIXERS - Google Patents

Description

Method and device for liquid discharge nozzle monitoring for the production of kiln egg masses in continuous tendon ckennii what.

The invention relates to a method and a device for monitoring the leakage of the liquid components, such as Binder, catalyst, disintegration promoter, among other things, in the production of, in particular, cold-curing foundry molding compounds ia continuously working Dui-chl on snow kenmische in.

& s Lind continuous screw mixers are known that work without monitoring the discharge of the liquid components. There is no guarantee that the molding compound that emerged at the end of the last mixing screw of the continuous screw mixer and fed directly into the molding or core box contains all, and especially those required, liquid components that are only added to a small extent.

A continuous screw mixer with discharge monitoring is also known, which is characterized in that that contacts are arranged at the points of addition of the liquid components in such a way that they are separated from the respective components are wetted and are switched in such a way that they switch on the liischerantrieb while the liquid is being supplied Maintain state and this when the

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Shut off the liquid supply (DT-AS 1 958 685). These Facility had the disadvantage that it shuts down the system if one of the liquid components is missing! not but already takes effect when the flow rate decreases so that a usable mixture is no longer guaranteed is · It also has the disadvantage that the functionality can only be guaranteed if they are to be monitored Liquids have sufficient electrical conductivity

The aim of the invention is to provide a method and an apparatus, whereby it is achieved that even with very small .Komponentenanteilen or electrically non-conductive liquid components a failure of the addition, which as a result of the often very small amounts added cannot be perceived by the operator, it is reliably recognizable » This can result in rejects in the production of molds and Cores are avoided, which are sometimes only recognized becomes when the first unusable forms and cores after The curing oil is removed from the molding or core box should be.

The essence of the inventive task is to create a To create liquid leakage monitoring, in contrast to the known devices is not only effective when the flow is completely absent, but even when the flow rate is reduced to such an extent that the mixture is no longer usable. She should continue can be used universally for all liquid media, regardless of their electrical conductivity

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The inventive method for monitoring the leakage liquid components in the production of, in particular, rapid cold-curing foundry molding compounds in continuous working continuous screw mixer is based on the fact that the liquid components to be monitored each one with an outlet before they enter the continuous screw mixer provided, the liquid to a certain extent accumulating Zwischengefäßι are supplied, the liquid level by a float integrated into a circuit for controlling the continuous screw mixer is monitored.

Lie device for carrying out the method consists in inrem, essential part for the invention in each one, each delivery line of a liquid component to be monitored associated intermediate vessel, which is arranged directly at the inlet of the liquid component in the mixer. The intermediate vessel has an angled outlet pipe above the level of the inlet for the liquid component as well inside a float with a guide pin, which is guided in the lid of the intermediate vessel · The altitude the float is adjustable, in and of itself well-known, non-contacting proximity switch can be scanned · This is connected to a switching amplifier and devices for signaling and control the drive of the continuous screw mixer.

Functional sequence of the device according to the invention is as follows:

The one coming from a feed pump or metering pump Immediately before the outlet into the screw mixer, the liquid component runs through the cylindrical, vertically arranged one Intermediate vessel. The liquid level in the kettle rises to the level that is horizontally arranged and curved by 90 ° at the end Outlet pipe · When the pumping is interrupted, the liquid level and the lowest point form the clear Cross section of the outlet pipe a plane.

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Constitutes promotion, then rises the liquid level and qer with him float as ordered daa intermediate vessel of non-conductive and acid-resistant, preferably Plastverkstoff, depending on the amount of fluid delivered to a gan :: particular to measure, wherein lent at its 3JT upper ^ mJe float provided with conductive material approaches the proximity initiator, which has been set to a certain level in the vertical direction, so far that a switching pulse is triggered. If the funding falls short of the default value or if it fails completely, the liquid level sinks (and so that the float goes back to a lower level or goes back to the initial level, which again triggers a switching pulse that can be used to shut down the mixer.

■ There is also the possibility of finding out the disruption of the liquid component supply signaled by the proximity initiator Using suitable amplifiers, switching devices and connecting cables to trigger acoustic signals or optically in signals.

In the drawing, an embodiment of the invention is shown, - ^ s show

Fig. 1 shows a continuous screw mixer with liquid from 1aufübe monitoring

2 shows a diagram of the liquid flow monitoring according to the invention.

The liquid outlet monitoring 1 according to the invention is at the transfer point between the two through electric motors 2 driven and by a swivel joint 3 interconnected mixing and conveyor screws 4 are arranged. The pivotable mixing and conveyor screws rest on a stand 5 »which is used to hold them with a vertical arranged Scuv / enkachse 6 is provided. The stand 5 serves at the same time to accommodate the feed and metering pump 7

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ORIGINAL INSPECTED

for the liquid component. The storage container for the liquid component is located outside the continuous screw mixer and is not shown in the drawing. Above the pivot axis 6 is for metering the solid components in the first mixing and conveyor screw a metering device 8 is arranged, which is attached to a the container 9 above is attached

The solid components coming from the bunker 9 via the metering device 8 into the mixing and conveying screw are wetted by the liquid component at the transfer point between the two mixing and conveyor screws 4, the above the liquid delivery line 10 according to the invention Liquid leakage monitoring 1 runs through. the The liquid component passes through the inlet pipe 11 into the intermediate container 12 and flows up via the outlet pipe 13 the dry components already in the mixer. The liquid level shown at rest

14 lifts the float 15 in when the liquid is pumped the proximity of the proximity switch 16, so that the metal part of the guide pin 18 of the float 15 triggers an impulse. The distance between the proximity switch 16 and the one made of a non-conductive material, preferably plastic material existing guide tube 19 of the intermediate vessel is through the height adjustability of the proximity switch

15 changeable, whereby in interaction with the different Level of the liquid level due to different delivery rates an interruption of the circuit takes place not only when the flow is completely absent, but also when the flow decreases by a predetermined amount.

The contact or the interruption are sent via connecting lines 20 and the switching amplifier 21 to a message Acoustic 22 or optical 23 signaling device passed on or to shut down the entire drive 24 of the Continuous screw mixer used.

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Claims (1)

Claims 1 · Procedure for monitoring the start-up of the liquid Components in the manufacture of In particular quick-cold-hardening oil-egg-shaped masses In continuously working continuous screw mixers, characterized in that the to be monitored Liquid components before they enter the mixing tool; each one provided with an outlet that accumulates the liquid to a certain extent Intermediate vessel are supplied, the liquid level of which is in relation to the flow rate through a float integrated into a "^ circuit to control the flow miser is monitored" 2 »Device for carrying out the method according to claim 1, consisting of a continuous screw mixer associated storage and dosing devices for solid and liquid components as well conveyor and control facilities, thereby marked »daft Each delivery line (11) of a liquid component at its mouth in the In the area of the mixing and conveyor screw (4) an intermediate vessel (12) is assigned, which is above the level of the inlet pipe (| 1) of the liquid conveying line (10) lying flow pipe (13) and a arranged in its interior, by a guide • pin (18) in the guide tube (19) of the intermediate vessel θ (12) has guided float (15), the height of which by an adjustable, known per se, contactless working proximity switch (16) in connection with a switching amplifier (21) and devices for signal output (22, 23) and for controlling the mixer (24) can be scanned. -2- 809825/0628 5. Device according to claim 2, characterized in that that the intermediate vessel (12) and the float (15) are made of non-conductive and acid-resistant material, preferably made of plastic. 4. Apparatus according to claim 2 and 3ι characterized in that the Fünrungszapfen ^ ¹⁸ ) of ^the float (15) at its, the proximity initiator (16) facing end, with the proximity initiator (16) in operative connection metal part (17) carries. 809825/06? $