JPS6025631B2 - Pit barrel type multistage pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to the structure of a bit barrel type multi-stage pump in which both suction pumps are arranged in the first stage.

[Background of the invention]

A conventional pump of this type will be explained with reference to FIGS. 1 and 2.

In the figure, 1 is a first-stage impeller, which has an upper suction row a, a lower suction port lb, and a discharge port lc. 2 is a next-stage impeller, 3a to 3d are conduits connecting the discharge port lc of the first-stage impeller 1 and the suction port 2a of the next-stage impeller 2, 4 is a rotating shaft, and 5 is a barrel.

When vanes 1 and 2 are driven, the fluid inside the barrel moves to A in the center of the figure.
, B, the air passes through the first stage impeller 1, through the conduits 3a to 3d, and is guided to the suction port 2a of the next stage impeller 2, as shown in FIG.

However, the casing structure of the first pump has a very complicated shape and is usually a cast structure, which inevitably increases the weight and increases the cost. [Purpose of the Invention] This invention uses a steel plate structure for the first stage pump casing that is easy to weld, thereby achieving significant cost and weight reductions, and a steel plate bit that can perform almost the same function as a cast bit barrel type multi-stage pump. The purpose of this invention is to provide a structure for a barrel-type multi-stage pump.

[Summary of the invention]

This invention connects the discharge port of the first-stage impeller and the suction port of the next-stage impeller with a flow path that covers the upper suction port of the first-stage impeller and is composed of inner and outer conical steel plate casings, and This system has a straight cylindrical suction path that penetrates orthogonally to the conical surface of the flow path and connects the inside of the barrel to the upper suction port.The structure is extremely simple, and it can be easily manufactured by welding. This is a technical measure that allows it to perform almost the same function as a bit-barrel type multi-stage pump with a cast pot.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 3 and 4.

The same parts or corresponding parts as in FIGS. 1 and 2 are given the same reference numerals and will be explained. The first stage impeller 1 has an upper suction port la and a lower suction port lb on the upper and lower sides, and a discharge port lc provided with a diffuser 6 on the outer peripheral side. A next-stage impeller 2 is coaxially mounted above the rotating shaft 4 to which the impeller 1 is fixed. This impeller 2
The suction port 2a and the discharge port lc of the first stage impeller 1 are connected to inner and outer steel plate casings 7a and 7b so as to cover the upper suction port la.
They are connected by conical channels 7a and 7b. As shown in the figure, a plurality of straight suction passages 8a to 8c are radially provided in the middle of the flow passage 7, passing through the conical surface of the passage 7 at right angles and fitting the inside of the barrel 5 to the upper suction port la. When the rotating shaft 4 equipped with the impellers 1 and 2 is driven, the water in the barrel 5 is sucked up by the suction port lb on the lower side of the impeller 1, and passes through the suction channels 8a to 8c to the suction roller on the upper side of the impeller 1. It flows into a and is sucked up.

The water pressurized by the impeller 1 passes through the diffuser 6 and rises in the conical flow path 7, reaches the suction port 2a, and then passes through the impeller 2.
It is further sent to the next stage impeller. The inside of the conical flow path 7 has a relatively large volume, and the discharge port lc of the first stage impeller 1 and the suction port 2a of the next stage impeller 2 communicate almost linearly, so that the flowing water It has the effect of keeping flow loss small. In addition, the suction channels 8a to 8c are the channels 7
Since the straight path is arranged perpendicularly to the conical surface of the barrel 5, the space between the entrance of the straight path and the inside of the barrel 5 can be widened as shown in FIG. 3, and this has the effect of minimizing losses due to the generation of vortices. [Effects of the Invention] As explained above, according to the present invention, the discharge port of the first-stage impeller and the suction port of the next-stage impeller are connected by a flow path composed of inner and outer conical steel plate casings, In addition, a direct suction hole is provided perpendicular to the conical surface of the flow path, and the inside of the barrel is conveyed to the upper suction port of the first stage impeller, so it performs the same function as the structure of a conventional bit-barrel type multi-stage pump. Of course, the structure is extremely simple, it can be easily manufactured by welding, and it is possible to significantly reduce costs and weight.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing the first stage structure of a conventional bit-barrel type multi-stage pump, FIG. 2 is a cross-sectional view taken along line 1-1 in FIG. FIG. 4 is a longitudinal sectional view showing the first stage structure, and FIG. 4 is a sectional view taken along the Rolo line in FIG. 3. 1... First stage impeller, la... Upper suction port, lb... Lower suction port, 2... Next stage impeller, 2a... Next stage impeller suction port, 5...
・Barrel, 7... Conical channel, 8a to 8c・
...Inhalation direct victory. Figure 2 Tsutomu's figure Approximately 4 figures Brown 3 figures

Claims (1)

[Claims] 1. In a pit barrel type multistage pump with both suction pumps arranged in the first stage, the discharge port of the first stage impeller and the suction port of the next stage impeller are covered with the upper suction port of the first stage impeller, and inner and outer conical steel plates are used. Connected by a flow path formed by a manufactured casing,
A pit barrel type multi-stage pump characterized in that a cylindrical straight suction passage is provided which penetrates orthogonally to the conical surface of the flow passage and communicates the inside of the barrel with the upper suction port.