DD159251A3 - APPARATUS FOR MIXING THE MOISTURE - Google Patents

Abstract

The invention relates to a device for mixing the dampening solution for the printing forms of offset printing machines. The aim of the invention is to provide a functionally reliable, easy to manufacture and operate device. According to the task is in devices that are equipped with a supply and a Dosierbehaelter for Aetzloesung, a Mischbehaelter for dampening solution and an interposed in the supply line for the water, the Aetzloesung from metering into the Mischbehaelter suction jet pump, a good mixing of the Aetzloesung in the storage container with simple, low-bothering technical means as well as an exact variable, easy-to-handle dosage d. Aetzloesung for dampening solution to allow. For this purpose, the Dosierbehaelter is designed as an overflow vessel, fixed i. Reservoir installed u. connected to a pump from the latter Aetzloesung connected by a pressure line and contains a vertically displaceable Verdraengerkoerper.

Description

VEB Combined Polygraph

"Werner Lamberz" Leipzig __ _c .

P 139

Device for mixing the dampening solution Field of application of the invention:

The invention relates to a device for mixing the dampening solution for the printing forms of offset printing machines.

Characteristic of the known technical solutions:

A known device (DE-PS 12 63 020) for mixing the Ätzkonzentrates and the water for the production of dampening solution for the printing forms of offset printing machines consists of a storage and a dosing tank for the etching solution and a mixing vessel for mixing) 15 of the etching solution with water, wherein the containers are connected in the order mentioned by pipelines, the dosing container has a device for regulating the etching liquid to be dispensed and in the mixing container a liquid level controller is installed, the supply of the etching liquid from the dosing container and the supply of water into the mixing container via a solenoid valve controlled by a water jet pump and the dampening solution in the wet box of the dampening pump pump.

25

Since the etching solution consists of various constituents, for example gum arabic, phosphoric and nitric acid,

exists, it can come in the said device in the reservoir to concentration differences due to demixing of individual components. The same applies if, due to poor print quality, a component is added to the storage container. Under certain circumstances, it may even, in particular by gum arabic, for skin formation on the etching solution.

Another disadvantage is that the solenoid valves in addition to the acid resistance must have greater reliability. It is therefore necessary at certain intervals, a rinsing or cleaning process with water.

This requires, inter alia, a relatively complicated structure of the device.

The device for producing the dampening solution according to DE-PS 14 42 578 has an airtight storage container for the etching solution, arranged at the bottom of the outlet nozzle in the designed as a floating body, also arranged with a liquid level control mixing container dispensing container projects. In the supply line for the water, a jet pump is interposed, the intake nozzle dips in raised to a certain height measuring vessel in this.

Particularly disadvantageous in this device must be considered for refilling and for cleaning of the mixing container storage tank. Apart from an additional required at the outlet nozzle, tightly closing shut-off valve, the handling of the filled reservoir is physically demanding and cumbersome.

A short-term replenishment of a component of the etching solution and thus the change of its concentration in FoI

- 3 - 4 ^ t U

ge an unsatisfactory printing result is not possible in this embodiment of the reservoir.

Object of the invention:

The aim of the invention is to provide a functionally reliable, easy to manufacture and operate device for mixing the dampening solution for the printing forms of offset rotary printing presses.

Essence of the invention:

75

The invention is based on the object, in devices of the type mentioned, which has a reservoir for etching solution, a dosing for measuring a variable amount of the etching solution and equipped with a liquid level mixing container for the existing of etching solution and water dampening solution, in which the supply line for the Water protrudes, which contains a control valve with downstream jet pump, the suction line is connected to the dosing, have a good mixing of the etching solution in the reservoir with simple, little prone to failure tech - (_) African means and an exact, variable, easy-to-use dosage to allow the etching solution for the dampening solution.

90

For this purpose, the metering container according to the invention is designed as an overflow vessel, permanently installed in the reservoir and connected to a pumping from the latter etching solution pump through a pressure line and contains a in the region between the connected to the suction of the jet pump drain and an upper reaches for the etching solution vertically displaceable displacer.

Because out of time for the suction of the etching solution

By the jet pump from the dosing into the mixing tank, the pump can either constantly promote etching solution in the dosing and on the upper run back into the reservoir, an intensive mixing of the etching solution is guaranteed and are separate secretions of individual components in a sequence demixing. This is particularly important if, due to a poor print quality, the concentration of the etching solution in the reservoir should be changed in the short term by adding a component.

The device has a simple structure, is easy to maintain and use, allows a trouble-free refilling of the etching solution and does not require acid-resistant control valves. "The dosing tank allows very sensitive, exact and reproducible dosing of the etching solution.

Due to the long available to fill the dosing tank with etching time a simple pump only low capacity, for example in plastic version required.

To set the desired concentration of dampening solution, it is advantageous according to the invention to attach to the displacement end face an actuating rod which carries a communicating with a fixed frame arranged scale pointer and can be locked via a screw relative to the housing of the dosing. The scale can be calibrated to the concentration values required for the dampening solution. 130

Embodiment:

The invention will be explained in more detail below on a Ausführungsboi «game. In the accompanying drawing shows:

for mixing the dampening solution in tlw. Scheme. table presentation

In the reservoir 1 for the multi-component, such as gum arabic, phosphoric and nitric acid, causticized solution 2 is a driven by a flanged to the cover 3 of the reservoir 1 electric motor 4 driven pump 5. Whose tlw. Above the liquid level of the etching solution 2 moved

Pressure line 6 is connected to the arranged below the upper reaches 7 _x flow 8 of standing in the reservoir 1 - dosing 9.

The drain 12 connected to the suction line 10 of the jet pump 11, which is likewise located above the liquid level of the etching solution 2, is arranged in the vicinity of the bottom 13 of the metering container 9. In the latter there is a displaceable body 14, which can be displaced vertically in the region between the outlet 12 and the upper run 7, to which an actuating rod 18 guided in the lid 16 screwed to the housing 15 of the metering container 9 is attached, equipped with a handle 17,

\ 160

To ensure an unobstructed circulation of the etching solution 2 in the metering 9, the housing 15 has inside between the outlet 12 and the upper reaches 7 a relative to the displacement body 14 larger diameter. The firmly connected to the displacer 14, a vertical slot 19 in the housing 15 of the dosing 9 passing pointer 20 points to the frame fixed, depending on the concentration of the etching solution 2 in the fountain solution 21 of the mixing container 22 calibrated scale 23 in a threaded bore of the Cover 16 radially guided to the actuating rod 18 screw 24 is used to adjust the displacement body 14 in a desired position,

The jet pump 11 is connected with the interposition of the solenoid control valve 25 to the supply line 26 for the water and via the drain line 27 to the mixing vessel 22. In the latter is a height adjustable with 2 electrical contactors 28; 29 equipped liquid level controller 30 for controlling the solenoid control valve 25 in conjunction with the pump 5 driving electric motor 4 is arranged.

For not belonging to the subject invention, a person skilled in the obvious electrical Schaltungsan order for the device should be mentioned here only as conditions to be observed »that the delivery time of the jet pump 11 must be greater than that for the complete extraction of the etching solution from the Metering 9 required time, the pump 5 is always out of operation with open solenoid control valve 25 and the dosing 9 is filled in any case before the opening of the solenoid control valve 25 to the specific volume for the dosage. Since the latter, conveniently to be controlled separately with respect to the time to be controlled process much shorter than the decrease in the liquid level of the fountain solution 21 in the mixing container 22 from the upper contactor 28 to the lower contactor 29 of the liquid level controller 30, with the help of the pump 5 in the remaining time, the etching solution constantly zwisehen reservoir 1 and dosing 9 pumped around and mixed with it and a skin formation can be prevented.

If, in the short term, the composition of the etching solution 2 is to be changed by the addition of a constituent, for example acid, due to an unsatisfactory printing result, this can easily take place after opening the lid 31 contained in the cover 3 of the reservoir 1,

Not shown in the drawing are the connection »

pipes, including pump, for the dampening solution between the mixing tank and the dampening solution boxes of the individual dampening units,

Due to the consumption of dampening solution for the printing process, the liquid level of the dampening solution 21 in the mixing container 22 drops. During this process, the driven by the electric motor 4 pump 5 fills the dosing 9 to · to the upper reaches 7 with etching solution 2 and then promotes the latter, causing their mixing back into

the reservoir 1 * In order to avoid a drop of the etching solution 2 in the metering 9 to the level of the inlet 8 after switching off the pump ^K -> ^J 5, a check valve should be conveniently installed between the pump 5 and the metering 9 in the pressure line 6 , It is also conceivable to arrange the inflow 8 above or at least at the same level with the upper flow 7 delimiting the metering volume in these cases.

In contrast, in the example of FIG. 1 without built-in check valve respectively between the inflow 8 and the drain 12 remaining liquid volume for the dosage available »

If the liquid level of the humidifier 21 has reached the lower contactor 29 of the liquid level controller 30, the Mägnet control valve 25 is opened, the motor 4 for the pump 5 having already been switched off. It runs as long as water and etching solution 2 through the drain line 27 of the jet pump 11 into the mixing tank 22 until the liquid level has reached the upper contactor and the solenoid control valve 25 is closed. At the latest by this time, the volume of the etching solution 2 intended for the metering was sucked out of the metering container 9. This condition applies to each set by adjusting the displacement body 14 on the scale 23 and to be fixed by the screw 24 amount of etching solution 2,

Claims (2)

Invention claim:
250 An apparatus for mixing the dampening agent for the printing forms of offset rotary printing presses with an etching solution storage tank, a metering tank for metering a variable amount of the etching solution and a mixing tank equipped with a liquid level controller for the dampening solution consisting of etching solution and water into which the water supply pipe projects, which contains a control valve with downstream jet pump, the suction line is connected to the dosing, characterized in that the dosing (9) formed as an overflow vessel, fixed in the reservoir (1) and installed with a latter of the etching solution (2) pump ( 5) is connected by a pressure line (6) and a in the region between the with the suction line (10) of the jet pump (II) connected drain (12) and an upper run (7) for the etching solution (2) vertically displaceable displacer (14). 2. Device according to item 1, characterized in that on the displacement body (14) the front side an actuating rod (18) is fixed, which carries a with a frame fixedly arranged scale (23) communicating pointer (20) and with the aid of a screw (24) relative to the housing (15) of the dosing (9) is lockable. For this ή page drawing