GB2218137A - Apparatus for mounting and fixing plunger pump units into a borehole - Google Patents

Description

1 1 1 '2_ 2 18 13 7 APPARATUS MR HDURYM AM F12CM PLU PUMP UNM INTO A

BCMBXE The invention concerns apparatus for mounting and fixing 5 plunger pump units into a borehole.

The f ield of application of plunger pumps is continually widening at the expense of traditional centrifugal pumps. The reason for this is that although its manufacture imposes higher technical requirements on the manufacturer, for the user both its mounting and its operation are appreciably simpler, less expensive and thus more economical. The pump-motor units are almost exclusively vertically arranged relatively long machines of small diameter and are thus also suitable for operation when mounted in boreholes lined with steel tubing. Most users of plunger pumps chose plunger pumps for raising water precisely becaue with this method both the utilisation of the water (e.g. in water works) and the reduction of the level of ground water (e.g. in open-cast mining, keeping working trenches dry in construction work) may be performed relatively simply, quickly and economically.

In the conventional construction of a water-raising system in boreholes with plunger pumps, the plunger pump is suspended from its own pressure pipe. A supply cable and, if required, indicating-sensing cables are fixed to the presure pipe at predetermined intervals.- Mounting takes place by means of a method similar to drilling because the pipes are connected to each other by threaded or screw-nipple couplings because flanged pipe couplings would require an unjustifiably large drilling pipe diameter. The mounting of pumps of higher output (more than 5 M3/p) especially requires large and heavy mounting means, including drilling tower and a rotating means, as well as technically skilled labour; moreover the mounting and demounting times are relatively long. The material requirement of the pressure pipe is significant, due to the threaded connection the well thickness is large and the quality requirements rela ting to the material of the pipe are also high.

2 It may be justifiable to replace the obvious-seeming solution of a suspension system by the use of another system if then one may obviate the pressure pipe requiring costly and intricate munting.

The pressure pipe fulfils two roles: it conveys the water and it is the supporting mechanism of the pump unit. The first role may be taken over by the liner pipe of the borehole which has the additional advantage that because of its larger diameter the flow velocity is reduced, friction losses are decreased, the power consumption becomes-more favourable and any water shock arising when the pump is stopped is also reduced. To suspend the machine the most expedient means to use are flexible loadcarrying machine elements, e.g. stranded steel cables, which are mass-produced and are thus inexpensive articles. Moreover, machines (winches) required for shifting the pump unit are also commercially available. The pulling force required for the displacement is significantly lower than in the case where the whole length of the pressure pipe must also be raised; this is particularly so in the case of mountings at great depth.

Thus when the functions of the pressure pipe are separated, the advantages of utilising plunger pumps are therefore further increased and their field of application is widened. In the case of a constructional solution utilising suspension on a rope or cable device must be mounted on the pump unit which enables, - after lowering the pump the desired location, a sealing system above the pump to come into operation which separates the highpressure spee above the pump from the low-pressure space below the pump.

A preferred embodiment of apparatus according to the invention is shown in Figure 1 in longitudinal section and in Figure 2 in plan view.

The left-hand side of Figure 1 illustrates the apparatus during displacement, such as raising and lowering; while the right-hand side illustrates it in a fixed condition. Attachment lugs 11, 14 for the ropes are not disposed in the same plane, but rather are, as may be seen f rom the plan view of Figure, 2, t 3 disposed mutually offset by 901.

A pipe section 2 is connected to the pump unit 1 or to its check valve. A cable guide tube 3 welded to the pipe section 2 at an angle has a stuffing-box 4 at its upper end to ensure that water should not be allowed to flow back into the low-pressure space adjacent the cable 5 passed through the pipe 3. A supporting shoulder 6 is welded to the pipe section 2 and carries a seal 7. The seal 7 tends to take up the shape shown in the left-hand side of Figure 1 partly as a result of the resilience of its own material and partly under the effect of the reinforcing core 8 which has been baked into it. The deformed shape assuring the sealing is brought about by the displacement of a clamping ring 9. The respective profiles of the supporting shoulder 6, the seal 7 and the clamping ring 9 are such as to assure the desired and most expedient sealing shape both during displacement and in the fixed condition.

During displacement the whole structure is suspended from transporting rope or cable 10 connected to the lugs 11, of which there are at least two. The f ixing rope or cable 12 is loose and hence the mass of the machine unit maintains the spring 13 via a spring support ring 16 in a compressed condition, i.e. the clamping ring 9 is ip a raised position. 13y gripping the f ixing rope 12 at ground level and further relaxing the transporting cable 10 the mass of the machine unit is transferred via the lugs 14, of which there are at least two, to the fixing cable 12. The spring 13 forces the clamping ring 9 downwardly and this actuates the seal 7. After starting the pump up the borehole is filled wth water to the level of the overflow, therefore the increasing pressure tends to maintaining the seal 7 in a deformed position even after the clamping ring 9 is raised. Assuming that both the seal 7 and the relief valve of the pump seal perfectly, the machine unit could be raised only by extremely high forces. In order to avoid this, bores 15 are formed on the supporting shoulder 6. When raising of the machine commences, the clamping ring 9 is lifted by tensioning the transporting rope 10, hence the bores 15 are unsealed and water is discharged from the drill F 4 pipe. The f ixing and transporting- ropes are taken out of the water space and passed via stuffing boxes at the head of the borehole.

t A z -zl CLADS 1. Apparatus for mounting and f ixing machine units equipped with plunger pumps in a borehole, comprising a pipe section adapted to be mounted to the pressure pipe of the machine unit, a sealsupporting part rigidly fixed to the pipe section, a resilient seal on said part, a spring supporting ring mounted at the side of the pipe section opposite the machine unit, first means for connection to a fixing rope, second means for connection to a transporting rope, a clamping member for clamping and deforming a seal, and a spring for displacing the clamping member towards and away from said seal.

2. Apparatus according to claim 1, wherein said seal has a reinforcing core.

3. Apparatus according to claims 1 and 2, wherein at least one transfer bore is formed on the seal-supporting shoulder.

4. Apparatus according to claim 1, substantially as herein described with reference,to an as shown in the accompanying drawings.

5. A plunger pump unit including apparatus according to any preceding claim.

6. A plunger pump unit according to claim 5 with fixing and transporting ropes attached to said first and second means, respectively Published 1989 atThe Patent Office, State House,66,71 High Holbern, London W, GIMTP. Further copies maybe obtainedfrom The Patent Office. Sales Branch, St Mary Cray, Orpington, Kent BF.5 3RD. Printed by Multiplex techruques Itd, St Mary Cray. Kent, Con. 1/87