JPS589704B2 - Centrifugal liquid purifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid purifier, and more particularly to a centrifugal liquid purifier.

The centrifugal liquid purifier according to the present invention is extremely effective in removing mechanical impurities and purifying liquids (oil, fuel, etc.).

Centrifugal liquid purifiers are known in the art, consisting of a vertical hollow shaft rigidly fixed to a base and provided with a liquid inlet and an outlet.

A cylindrical rotating body is attached to a sliding contact bearing on the shaft, and the rotating body is connected to a sheath, a mantle with a strip wrapped in a spiral, and a lower and upper impeller located above and below the spiral, respectively. Become.

Spacers are sandwiched radially between each turn of the strip spiral parallel to the hollow shaft, which spacers together with the strips form a liquid flow gap.

The incoming liquid is directed into the gap through the cavity between the impeller disk and the helical edge of the strip, and the purifying liquid is removed from the gap through the cavity.

Under the action of centrifugal forces, mechanical contaminants are separated from the liquid in the gap and deposited on the strip surface (see, for example, Swedish Patent No. 392,676).

In such a centrifugal purifier, the degree of mechanical impurity removal and liquid purification in the gap formed by the strip spiral and the gap plate is not uniform. This is attributed to the fact that the distribution of is dependent on the radius of the location which reduces the liquid purification rate.

The object of the invention is to obviate the above-mentioned drawbacks.

The main object of the present invention is to provide a centrifugal liquid purifier with a uniform degree of liquid purification by arranging the impeller disk against the edge of the strip helix to ensure an optimal distribution of the liquid flow rate in the gap. It is on offer.

According to this and other objects, the present invention discloses:
It consists of a vertical hollow shaft fixed to the base, having a liquid inlet and an outlet, and having a cylindrical rotating body, the rotating body consisting of a cannula and an impeller, and the cannula is arranged coaxially with the hollow shaft. A strip plate is wound spirally, and spacer plates are sandwiched radially parallel to the hollow shaft between each turn of the strip plate, and the spacer plate is wrapped together with the strip plate. A centrifugal liquid cleaner that forms a gap for liquid flow and is made in the form of a disk with impellers installed at both ends of a cannula with strips and ribs fixing the edges of the spacing plates. In the device, according to the present invention, the impeller disks are constructed and fixed such that the distance between each disk and the corresponding edge of the strip spiral satisfies the following conditions.

Here, t1: Distance between the disk of one impeller and the corresponding edge of the strip helix t2: Distance between the disk of the other impeller and the corresponding edge of the strip helix R: Distance between the disk of the other impeller and the corresponding edge of the strip helix Maximum radius r: Movement radius of the strip helix ro: Minimum radius of the strip helix The centrifugal liquid purifier according to the present invention improves the degree of liquid purification while maintaining the same capacity as the centrifugal purifier according to the known technology.

Furthermore, the centrifugal purifier according to the present invention requires at least twice as long an operation period until the next time the precipitate is removed from the rotating body as compared to a purifier of known technology.

Next, the present invention will be specifically described in detail with reference to the accompanying drawings.

The centrifugal liquid purifier has a hollow shaft 1 whose lower end is fixed to the base 2.
(Figure 1).

In the cavity A in the lower part of the shaft 1 there is an inlet junction pipe 3 through which the liquid flows into the purifier and an outlet junction pipe 4 through which the purified liquid flows out.

A cylindrical rotating body 7 for rotating the liquid to be purified is mounted on bearings 5 and 6 on the shaft 1.

A pressure disk 8 is provided at the upper end of the shaft 1, which connects the interior of the rotating body 7 to the connecting tube 4 via a tube 9 located in the cavity A of the shaft 1.

The pressure disk 8 aspirates liquid and at the same time serves as an upper thrust bearing for the cylindrical rotor 7.

In the center of the shaft 1 there is a hole 10 through which liquid is introduced into the rotating body 7.

The rotating body consists of a sleeve 11 formed by winding a strip 12 in a spiral manner, and a spacer plate 13 (FIG. 2) is provided radially for each turn of the strip.

The spacing plate 13 forms a gap 14 with the helix of the strip 12, the size of which depends on the thickness of the spacing plate 13.

The sleeve 11 has a press-fitted lower impeller 15 (FIG. 1) and an upper impeller 16 located below and above the spiral of the strip plate 12, respectively.
is provided.

The lower impeller consists of a disc 17, which has ribs 18 (Fig. 3) arranged radially and uniformly on the circumference, and the lower part of the disc has a groove wheel 19 (Fig. 1). ) and connects the rotating body and drive device (not shown) via a belt transmission (not shown).

The impeller 15 serves to twist the liquid flow and also serves to align the rotating body with the bearing 6.

The upper impeller 16 consists of a disk 20, which has ribs 21 (FIG. 3) that radially divide the circumference into equal parts, aligning the rotating body 7 (FIG. 1) with the bearing 5, and keeping the liquid Helps twist the flow.

The edges of the gap plate 13 are fixed to the ribs 18 and 21 of the lower impeller 15 and the upper impeller 16, respectively.

The liquid enters the gap 14 via the cavity B formed by the sleeve 11 and the shaft 1 by means of radial channels formed by the impeller ribs 18 and the disc 17 and the lower edge of the helix of the strip 12. Sent.

The purified liquid is distributed to the upper edge of the spiral of the imperial plate 12, the disk 20
, and a radial passage formed by the ribs 21 of the impeller 16, and is taken out from the gap 14.

The rotating body 7 is surrounded by a sheath 22 fixed to the disk 17 of the impeller 15.

There is a hole (not shown) in the upper part of the sheath 22, which serves as an outlet for air when the rotating body 7 is filled with liquid.

The efficiency of a centrifugal liquid purifier is determined by the distance t1 between the disc 17 of the impeller 15 and the lower edge of the spiral of the strip plate 12, and the distance t2 between the disc 20 of the impeller 16 and the upper end of the spiral of the strip plate 12. Depends on your choice.

The relationship between these distances governs the distribution law of liquid flow rate in the gaps 14 and, ultimately, the purification efficiency in each of the gaps 14.

The best distribution of liquid flow velocity within the helical gap is a distribution that follows the following law.

However, ■: Liquid flow rate in the gap r: Radius of the gap The reason is that only this distribution of liquid flow rate ensures uniformity of the degree of purification in each gap, thus ensuring the highest efficiency. Because it does.

Such a velocity distribution in the gap 14 of the helix of the strip 12 is achieved if the distance between each of the discs 17, 20 and the corresponding edge of the helix of the strip 12 satisfies the following conditions: .

Here, t1: distance between the disc 17 of the lower impeller 15 and the corresponding edge of the strip 12 t2: distance between the disc 20 of the upper impeller 16 and the corresponding edge of the strip 12 R: strip spiral Maximum radius r: Variable radius of the strip helix ro: Minimum radius of the strip helix In the centrifugal liquid purifier having the above structure, the shape of the disc 17 of the impeller 15 and the helix of the disc and the strip 12 The distance t1 from the lower edge of the gap 14 is such that it minimizes the influence of Coriolis on the purification of the liquid in the gap 14 and the fluid resistance that the liquid delivered to said gap must overcome, and also that the sediment can slide out of the gap 14 and the exterior selected to ensure good accumulation on the inner walls of 22.

The shape of the disc 20 of the impeller 16 and the distance t2 between the disc and the upper edge of the spiral strip are determined so as to satisfy the condition of formula (I).

A centrifugal liquid purifier operates as follows.

The liquid-filled rotating body 7 is rotated by a drive (not shown) via a V-belt transmission (not shown).

The liquid to be purified enters the centrifugal purifier via the junction tube 3.

The direction of liquid flow is indicated by arrow C. The liquid enters the radial passages via the cavity A, the hole 10 in the shaft 1 and the cavity B.

In this radial passage, the liquid flows through the ribs 1 of the impeller 15.
It is twisted by B to the angular velocity of the rotating body T and enters the gap 14.

The centrifugal force acting on sludge particles is always directly proportional to the particle radius;
Since the height and length of the gaps are all the same, increasing the efficiency of liquid purification requires that the residence time of the particles in the gaps of the strip helix is inversely proportional to the particle radius, which means that the gap Satisfied if the velocity of the liquid within is distributed according to law (I).

Then, if condition (U) is realized, law (I) is secured.

The fluid velocity distribution between the gaps 14 in the spiral strip is expressed by the following differential equation.

where Qp=flow rate of fluid passing through the radial passage formed by the ribs 18 and disk 17 of the impeller 15 and the lower edge of the helical strip 12; S=cross-sectional area of the gap 14 - radius r.

The average velocity of the flow in the gap along.

The cross-sectional area of the gap 14 is derived from the following equation.

S=π(r2-ro2) Considering that the flow rate of the passing fluid is equal to Qp=2rrt2V2, the transport flow rate can be expressed as Qt=Q-Qp=2πr71V1, which leads to the following relationship for the velocity in the radial passage: I get run over.

Here, Q = centrifuge capacity, ■1=Velocity at the entrance of the radial passage, ■2=Velocity at the exit of the radial passage.

Therefore, in order to realize V/r=constant, it is necessary that the velocity in the radial path satisfies the relationship (2).

In the case of radial fluid flow, inertial Coriolis forces appear in the rotating passage of the centrifuge, and this Coriolis force overwhelms other forces and governs the nature of the fluid flow within the rotating body elements.

The lateral pressure gradient within the radial passage, determined by the Coriolis force, can be calculated from the equation:

Pc=2ωρVγα(3) Here, α=angle between adjacent ribs 18, ρ = density of cleaned fluid, ω = angular velocity of the rotating body.

As shown in Figure 4, the Coriolis forces with magnitudes Pc1 and Pc2 appearing in the ribs 18 and 21 of the inlet and outlet cavities create vortices rAJ and rBJ, speeding up the main flow in the gap (Pc1> Pc2) or slowed down (PC2>Pet).

Additionally, the fluid resistance of the radial passages is determined by the Coriolis force, which overwhelms the forces determining viscous and local losses.

The pressures Pc1 and Pc2 are determined by the structure of the impellers 15 and 16, the number of ribs 18 and 21 and the shape of the discs 17 and 20, ie dimensions t1 and 72).

Formula (I) is conditional: Pcl=Pc2(4) Calculated below.

That is, by substituting equation (2) into equation (3) and considering equation (4), the following equation is obtained.

If the flow deviates even slightly from law (I), Pc1 and Pc2 change to restore this law, and an automatic adjustment takes place.

Particles having a density different from that of the liquid to be purified are deposited on the surface of the strip plate 12 under the action of centrifugal force, and the purified liquid is deposited on the surface of the strip plate 12.
It is taken out through the pressure disk 8, the tube 9 and the connecting tube 4 by the disk 20 and the ribs 21 of the impeller 16 via the radial passage formed by the upper edge of the helix.

Since the deposits are evenly deposited in the gap 14, the time during which the purifier can be operated continuously without having to stop operation to remove the deposits from the rotating bodies is increased several times.

The above centrifugal liquid purifier has a diameter of 160mm,
With a height of 200 mm and a rotating body of 8,000 revolutions per minute, it has a capacity of 40 liters per minute and ensures liquid purification by removing wear-resistant metal particles over 1 micron in size. .

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a centrifugal liquid purifier according to the present invention, FIG. 2 is a cross-sectional view showing a part of the strip spiral along line 1-1 in FIG. 1, and FIG. 3 is a cross-sectional view taken along line II in FIG. FIG. 4 is a flow explanatory diagram of one gap. 1...Hollow axis, 2...Base, 3...
... Intake joint pipe, 4 ... Output joint pipe, 5, 6
... Bearing, 7 ... Cylindrical rotating body, 8 ...
...Pressure disk, 9...Pipe, 10...
- Hole, 11... Mantle, 12... Band plate,
13... Spacing plate, 14... Gap, 15
, 16... impeller, 17... impeller disk, 1
8...Rib material, 19...Curved groove wheel, 20...
- Impeller disc, 21... Ribs, 22... Exterior.

Claims (1)

[Claims] 1. It has a vertical hollow shaft fixed to the base and having a liquid inlet and outlet, and the inlet and outlet are connected to corresponding cavities of a cylindrical rotating body attached to the hollow shaft. contact me,
It also has a mantle which is arranged coaxially with the hollow shaft and has a strip wound around it in a spiral shape, and between each strip of the spiral strip, a spacer plate is sandwiched radially parallel to the hollow shaft. The spacing plate together with the strip forms a liquid flow gap, and the impellers provided at both ends of the sleeve are made in the form of a disk with ribs fixing the edges of the spacing plate. In the centrifugal liquid purifier, the discs 17 and 20 of the impellers 15 and 16 are made and fixed such that the distance between each disc and the corresponding edge of the spiral of the strip plate 12 satisfies the following conditions. A centrifugal liquid purifier characterized by: Here, t1: distance between the disc 17 of one impeller 15 and the edge of the corresponding strip 12 t2: distance R between the disc 20 of the other impeller 16 and the edge of the corresponding strip 12 : Maximum radius of the spiral of the strip plate 12 r: Movement radius of the spiral of the strip plate 12 ro: Minimum radius of the spiral of the strip plate 12