GB2030479A - Liq. treatment of articles - Google Patents

Abstract

Apparatus for the liquid treatment of articles, for example during a galvanizing process, comprises a perforated drum for containing the articles, a tank (1) and a spraying device (2). The drum can be rotated, and the spraying device (2) can be pivoted about end regions (22) and (23) of an inlet pipe. The drum is supported on the tank (1) by bearings (5) and can be moved into sealing engagement with the spraying device (2), which is constructed as a chamber into which nozzles discharge. This results in liquid sprayed from the nozzles being forced into the drum to provide efficient rinsing of the articles while the drum and the spraying device (2) oscillate together. <IMAGE>

Description

SPECIFICATION Apparatus for the liquid treatment of articles This invention relates to apparatus for the liquid treatment of articles, such as mass-produced parts.

The liquid treatment may be, more particularly, a finsing treatment in a galvanizing process.

During a galvanizing process, mass-produced parts to be galvanized undergo various liquid treatments, some of which are intended to achieve thorough cleansing of parts. With known equipment, a perforated drum containing the mass-produced parts is moved into a specific treatment station for this purpose and undergoes the liquid treatment there. The drum is sprayed from the exterior by nozzles. Although this adequately rinses the drum, relatively little rinsing or treatment liquid penetrates the drum itself through the perforations in the drum casing. The consumption of treatment liquid and the power requirements for the corresponding circulation of the liquid are correspondingly high.

According to the present invention there is provided apparatus for the liquid treatment of articles, comprising a drum for receiving the articles, a tank within which the drum is rotatable, and a spraying device within the tank for spraying liquid towards the drum, the spraying device being pivotable about a horizontal axis, the distance between the axis and the spraying device being greater than the radius of the drum, the drum being movable into sealing engagement with the spraying device, whereupon the spraying device and the drum are rotatable together.

In a preferred embodiment in accordance with the present invention, the spraying device comprises a chamber which partially surrounds the drum and which has nozzles directed towards the drum. An inlet pipe for supplying liquid to the nozzles serves to su'pport the spraying device and provides the horizontal axis. The drum is supported on the tank by hydraulically displaceable bearings. Nozzles ari anged at at least one end of the drum provide an additional rinsing effect. In the operating position, the spraying device sealingly abuts the drum, with the result that the nozzles directed towards the drum force a sufficient quantity of treatment liquid into the drum for rinsing the articles.The drum is rinsed from the exterior while the spraying device in the form of a chamber is being set up, from which treatment liquid constantly issues during rotation to rinse the drum. The treatment liquid draining away is collected in the tank and is removed or is supplied to the spraying chamber again in a closed circuit.

Apparatus in accordance with the present invention permits the liquid treatment of mass-produced parts in a rotating drum with a smaller liquid consumption than the known equipment mentioned above. The treatment liquid, more particularly a rinsing liquid, is directed in an effective manner both externally to all the drum parts, and is also forced inside the drum for treating the parts. The quantities of liquid circulated can therefore be maintained at a relatively low level, energy thereby being conserved.

The consequent reduction in effluent being discharged is of significance since it reduces the load on cleansing equipment connected at the outlet, for example ion exchangers.

For a better understanding of the present invention and to show how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which: Figure 1 shows liquid treatment equipment with a spraying device illustrated in a rest position; Figure 2 is a side view of the equipment of Figure 1; Figure 3 is a top view of a plurality of outlet funnels arranged on a common pitch circle below the equipment; Figure 4 is a view corresponding to Figure 1 with the spraying device illustrated in an operating position; Figure 5 is a side view of the equipment of Figure 4; and Figure 6 is a view corresponding to Figure 5 with a treatment drum raised against the spraying device.

Figures 1 and 2 show liquid treatment equipment, for example rinsing equipment, in its rest position.

The equipment is at one of several successive treatment stations of a galvanizing apparatus. A spraying device 2 is supported by end walls 11 and 12 of a tank 1 and can be rotated about a horizontal axis 4. End portions 22 and 23 of an inlet pipe serve as axles for the spraying device 2. These end portions 22 and 23 are bent such that the radial distance between a spraying chamber 21 of the spraying device 2 and the horizontal axis 4 is greater than the radius of a treatment drum 34 to be used.

Distribution pipes 29 directed into the spraying chamber 21 lead off the inlet pipe.

In its rest position, the spraying device 2 is disposed in the lower region of the tank, in which a drum unit 3 is suspended. The drum unit 3 comprises a supporting structure 31 which is supported by lateral pivot pins 32 on corresponding bearings 5 which can be raised and lowered relatively to the tank. Generally vertical supporting arms 33 are secured to the supporting structure 31 and the treatment drum 34 is suspended rotatably on these arms 33. The supply of power to the drum generally takes place through these supporting arms 33. The drum 34 is driven through a gear drive driven by a motor on the supporting structure 31.

Treatment liquid enters through the end walls 11 and 12 of the tank 1 through an entrance chamber 16 and through valves (not shown) to reach the inlet pipe end 22 supported rotatably in a bearing 24. The liquid passes to the spraying chamber 21 through the distribution pipes 29 and is sprayed onto the drum 34 by nozzles 26 on these pipes 29. Liquid collecting in the tank 1 is drained offthrough an outlet 14 in the bottom of the tank 1.

This outlet is provided with a rotating, angled outlet connection 15 which is controlled by a motor 18 and a chain drive 19, and can be swivelled to discharge into any one of several (four in Figure 2) funnels 7 disposed on a common pitch circle.

In the rest position shown in Figure 1, hydraulic cylinders 51 which support the weight of the drum unit 3 on the bearings 5 are relieved. The inlet valves to the chamber 16 are closed.

In order to carry out the spraying treatment, an electric motor 64 is energised and moves the spraying device 2, by a chain drive 6, into an operating position shown in Figure 4. The drum 34 is rotated. The valves 16 are opened to allow untreated water to flow through the nozzles 27 of the spraying chamber 21 to the drum. Liquid for cleansing the drum 34 is sprayed through spraying nozzles 81 of a spraying device 8 at the ends of the drum 34. If the spraying device 2 has arrived in the operating position shown in Figure 4, then the first rinsing phase is terminated. The water inlets, like all other operating outlets which are controlled by electric switches, are interrupted.

The drum 34, controlled by magnetic switches, takes up a position in which an aperture 38 is directed downwards. It can be seen from Figure 2 that the drum 34 is formed by plates 36 which are interconnected by corner rods 35. End plates 39 form the lateral ends. Interchangeable sieve plugs 37 are provided in the plates 36 to make the drum waterpermeable.

From this operating position, the four hydraulic cylinders 51 are pressurised by the hydraulic unit 52 to raise the entire drum unit 3, with the result that the drum 34 takes up the position shown in Figure 6. The drum is forced against sealing ribs 28, extending around the periphery of the spraying device, and possibly other sealing members, to form a sealed cavity between the chamber 21 and the drum casing.

From this cavity, the treatment liquid from the nozzles 27 is forced into the drum 34 and hence sprays or drips onto the articles to be treated in a uniform manner. The drum 34 subsequently executes a controlled oscillating movement in the range permitted by the pipe ends 22 and 23, taking with it the spraying device 2, which has previously been disconnected from the drive motor 64 by a magnetic coupling 63. The corresponding chain drive 6 comprises a sprocket 61 on the pipe end 23 and another sprocket 62 on the output of the motor 64.

The motion of the drum 34 is stopped after a few adjustable oscillations. The drum 34 is then returned to the starting position in which the aperture 38 is directed downwards. The hydraulic cylinders 51, and consequently the drum 34, are lowered.

The drum 34, now free of the spraying device 2, then executes a few revolutions. This causes the liquid sprayed onto-the articles to run out into the tank from where it passes through the rotating outlet 14, 15 to the outlet funnels 7 coordinated by the actuator 18. The number of outlet funnels 7 is determined by the method used.

The spraying device 2finally swivels downwards again so that the drum unit 3 can be lifted out of the tank 1.

Where the equipment is used for rinsing, the used liquid can be returned to the treatment baths either directly or after concentration, thereby conserving water.

Depending on the type of treatment bath and the type of article, the rinsing operation with untreated water may be repeated, but one cycle should generally be sufficient. As far as possible, the used liquid should be returned to the treatment baths without the costly concentration process, and the treatment baths must be continuously replenished to make up for continuous losses due to evaporation.

After rinsing with untreated water, it may be desirable to perform a final rinsing operation using water which has been completely desalted, this operation being done with the same equipment in the same manner. This rinsing phase should proceed in as many stages as possible.

In many cases it may be very suitable to use separate water circuits for spraying the drum at the front end and for spraying in a radial direction. Water can then also be introduced through the pipe end 23 which, parallel to the pipe 22, is connected with the opposite spraying device 8. The bearing at the pipe end 23 would need to be constructed accordingly.

Claims (12)

1. Apparatus for the liquid treatment of articles, comprising a drum for receiving the articles, a tank within which the drum is rotatable, and a spraying device within the tank for spraying liquid towards the drum, the spraying device being pivotable about a horizontal axis, the distance between the axis and the spraying device being greater than the radius of the drum, the drum being movable into sealing engagement with the spraying device, whereupon the spraying device and the drum are rotatable together.

2. Apparatus as claimed in claim 1, in which the spraying device comprises a chamber which extends partially around the exterior of the drum and into which open nozzles directed towards the drum.

3. Apparatus as claimed in claim 2, in which the spraying device is supported by an inlet pipe through which liquid is supplied to the nozzles, the inlet pipe providing said horizontal axis.

4. Apparatus as claimed in claim 2, in which the periphery of the chamber of the spraying device is' provided with sealing ribs facing towards the drum.

5. Apparatus as claimed in any one of the preceding claims, in which the drum is suspended from a supporting structure by arms, the supporting structure being supported on the tank by bearings which can be raised and lowered.

6. Apparatus as claimed in claim 5, in which the bearings are hydraulically displaceable.

7. Apparatus as claimed in any one of the preceding claims, in which spray nozzles directed towards the drum are provided at at least one end of the drum.

8. Apparatus as claimed in claim 7, in which the spraying device and the spray nozzles are supplied with liquid through separate liquid circuits.

9. Apparatus as claimed in any one of the preceding claims, in which the spraying device is pivotable by means of a chain drive, which is disconnectable from the spraying device.

10. Apparatus as claimed in any one of the preceding claims, in which there is a rotatable outlet connection at the underside of the tank.

11. Apparatus as claimed in claim 10, in which the outlet connection can be rotated to discharge into any one of several outlet funnels arranged on a common pitch circle.

12. Apparatus for the liquid treatment of articles, substantially as described herein with reference to, and as shown in,the accompanying drawings.