JPS6193274A - Energy recovery device in seawater desalting apparatus - Google Patents

Abstract

PURPOSE:To enhance the efficiency of energy, by providing a nozzle for injecting seawater into a rotor, and by forming, in the wall surface of the rotor, receiving surfaces for receiving injected fluid in a such a form that the receiving surfaces are concave in the rotating direction of the rotor. CONSTITUTION:An output shaft 3 is disposed in the casing 2 of an energy recovery device 1, and is coupled thereto with a hollow drum-like rotor 6. Further, predesalted seawater is fed into the rotor 6 and is injected fro a nozzle 11. Grooves 13 are formed at predetermined pitches, having receiving surfaces 14 and feeding surfaces 15 to smoothen the impinging force of jet stream. With this arrangement, even if the flow rate of seawater is less, the energy is efficiently converted into a rotational motion.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an energy recovery device for reusing the pressure energy of undesalinated fluid discharged from a seawater desalination device.

[Conventional technology]

Conventionally, seawater desalination plants produce 50 to 60 kg of seawater.
Desalination is carried out by increasing the pressure to approximately /cd and supplying this to reverse immersion M'ltK.

However, in this reverse osmosis device, the desalination rate is about 40%, and the remaining 60% is discharged as seawater, and the high-pressure fluid energy boosted by the high-pressure pump is wasted.

In order to recover this energy, a system is currently being used in which a seawater desalination plant is equipped with an energy recovery device to supply undesalinated seawater from a reverse osmosis device and recover it as, for example, electricity.

As an energy recovery device, a multi-stage turbine pump 50 suitable for high-pressure fluid is generally used as shown in FIG. It outputs 53 rotations as output. In this turbine pump 50, the turbine blades 52 are arranged in multiple stages, so that the supplied jJj body energy can be efficiently recovered and undesalinated seawater can be discharged from the inlet 54.

(Problems to be Solved by the Invention) However, when the turbine pump 50 is used for energy recovery, the amount of fluid supplied is relatively large and normally requires 2 to 3rd/min.

Therefore, energy recovery is possible in plants with large flow rates, but in seawater desalination equipment on remote islands, the supply flow rate is 0.
．． In many cases, the speed is about 1 to 0.5 rd/min, which is not sufficient to rotate the turbine pump 50, making it impossible to recover energy.

An object of the present invention is to convert the pressure energy of the fluid into mechanical motion to enable energy recovery even if the flow rate of undesalinated seawater from a seawater desalination device is small.

[Means for solving problems]

The structure of the present invention is to arrange an output shaft connected to a rotor in a casing, provide a nozzle injecting untreated seawater in the rotor, provide a flow path in a side wall of the rotor to communicate between the inside of the rotor and the outside of the casing, and further A receiving surface is provided on the inner circumferential wall of the rotor to receive the fluid jetted from the nozzle, and the flow path is formed in an arcuate shape concave toward the rotational direction of the rotor so that the fluid flows centripetally from the outer circumferential end of the rotor. It is.

〔Example〕

The present invention will be described below based on embodiments shown in the drawings.

FIG. 1 is a sectional view of an energy recovery device 1 according to the present invention,
FIG. 2 is a sectional view taken along the line I-1 in FIG. 1.

This energy recovery device 1 is installed in a seawater desalination plant as shown in FIG. A high-pressure pump 42 that supplies seawater is an electric motor for driving the high-pressure pump 41.

The energy recovery device 1 is supplied with undesalinated seawater discharged from the reverse osmosis device 40, and is a system that recovers energy by converting fluid energy into rotational motion and assisting the driving of the electric motor 42.

In FIG. 1, an output shaft 3 is disposed inside and outside a casing of an energy recovery device 1, supported by bearings 4 and 5, and a hollow drum-shaped rotor 6 is connected to one end of the output shaft 3.

A joint 7 is connected to the outside of the casing 2 for supplying undesalinated seawater from the reverse osmosis device 40 into the rotor 6 and for discharging the fluid after energy recovery. ．． A discharge chamber 10 communicating with the outlet 9 and the inside of the potter's wheel is formed, respectively.

Reference numeral 11 denotes a nozzle located inside the rotor 6 and connected to the inlet 8 of the joint 7 by a connecting pipe 8a that passes through the inside and outside of the casing 2. The nozzle 11 bends and extends in the radial direction from the center of the rotor 6, and is connected to the inlet 8 of the joint 7 in the vicinity of the inner peripheral surface of the rotor. The jet nozzle 12 opens toward the direction of rotation of the rotor 6.

A groove 13 for receiving the jet from the nozzle 11 is formed in a wavy shape with a fixed pinch on the inner circumferential surface of the rotor. The attack surface is large and has a circumferential length of 14.
Each has a longer feeding surface 15 than the other.

Reference numeral 16 denotes a cover that is disposed on the nozzle 11 insertion side of the rotary wheel and closes one side of the rotor 6, and the nozzle 11 insertion portion is provided with a labyrinth type seal 17.

A plurality of openings 18 are provided on the inner surface of the cover 16 at regular pitches in the circumferential direction, and a flow path 19 is formed inside the cover 16 from the openings 18 toward the center. The inside of the rotor wheel communicates from this flow path 19 through the sole part 20 to the evacuation chamber 10, and seawater from the inlet 8 flows into the rotor 6 from the nozzle 11, passes through the flow path 19 from the opening 18, and is discharged. It constitutes a flow path system that reaches the chamber 10 and is discharged from the discharge port 9.

As shown in FIG. 3, this flow path 19 is formed in a concave arc shape toward the rotational direction of the rotor 6 so that a rotational force is applied to the rotor 6 by the 11TL excess fluid.

The energy recovery device 1 having the above configuration is used in the seawater desalination plant shown in FIG.

Note that the flow rate of seawater is 0.1 to 0.5 n(/min), and the pressure is approximately 60 kg/CJA.

This high-pressure water 7 flows down from the connecting pipe 8a to the nozzle 11,
Tri! 1 force is applied to rotate the opening 6 at high speed in the direction of the arrow in FIG.

Further, the seawater injected from the nozzle 11 flows through a flow path 19 in the cover 1 on the low pressure side that is open to the atmosphere through the outlet 9.
from the opening 18. As shown in FIG. 3, this flow path 19 is an arcuate path that is concave in the rotational direction from the opening 18 to the center of the rotor 6, so the rotating force is applied by the flowing fluid like a turbine pump. be done.

Thus, the opening 18 becomes an equal element in the fluid population of the turbine pump, the velocity triangle at this opening 18 is as shown in FIG. 3, and the cover 16 has a circumferential velocity u.

is given.

As described above, the energy of high-pressure seawater is first converted into the rotation of the rotor 6 by the injection from the nozzle 11, and then the energy is further changed IQ by the rotational force load at the opening 18 of the flow path 19 of the cover I6, and the energy is output The shaft 3 rotates at high speed to auxiliary drive the electric motor 42 and recover energy.

Note that the rotation speed of the rotor 6 during fluid supply is approximately 5.00.
0 rpm to 5.50 Orpm, but the groove 13 in the potter's wheel forms an attack surface 14 with a lower angle of attack to the jet, unlike a normal blade shape, so the jet's town γ
It is possible to smooth out the force, suppress the occurrence of vibration even during high speed rotation, and reduce resonance phenomena at critical speeds.

〔Effect of the invention〕

The present invention utilizes the energy of the fluid to increase the rotational speed of the output shaft even when the flow surface of the supplied high-pressure undesalinated seawater is small.
It has the effect of efficiently recovering energy even in small-scale flame water conversion plants.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the energy recovery device according to the present invention, Figure 2 is a sectional view of the energy recovery device according to the present invention;
The figure is a sectional view taken along the line I-'1 in Figure 1, Figure 3 is a front view of the cover, Figure 4 is a sectional view of the cover, Figure 5 is a schematic diagram of the seawater desalination plant, FIG. 6 is a conceptual diagram of a multi-stage turbine pump conventionally used for large flow rates. fil energy recovery device

Claims (1)

[Claims] 1. An output shaft connected to a hollow drum-shaped rotor is placed inside the casing, a nozzle communicating with the untreated seawater source of the seawater desalination equipment is installed inside the rotor, and the inside of the rotor and the outside of the casing are connected to the side wall of the rotor. A flow path is provided for communication,
The rotor has an attacking surface on its inner circumferential wall surface that receives the fluid jetted from the nozzle, and the flow path is provided so that the fluid flows from the outer circumferential end of the rotor in the axial direction, and streamlines are directed in the rotational direction of the rotor. An energy recovery device for a seawater desalination device characterized by being formed in a concave arch shape.