JPS6226044B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for injecting small proportions of additives into a fluid with a flow divider.

In order to inject the additive into the fluid stream at a constant rate, the fluid flow rate is divided into constant proportions,
It is often necessary to rejoin them afterwards.

Additives are injected into one of the divided circuits by means such as a pump, which results in a pressure drop relative to the main fluid stream. This pressure drop is not stable, so the stability of the flow rate ratio of the two circuits after division cannot be guaranteed, and therefore the stability of the ratio of additive to the main stream cannot be guaranteed.

The above-mentioned problems become more pronounced at high delivery rates, and therefore such an injection method can only be used at relatively low delivery rates.

The object of the invention is, in particular, to inject a small proportion of additive by means of a pump that varies the feed rate and to maintain a constant ratio of main stream to additive, even if a pressure drop with respect to the main stream occurs in the circuit. It is an object of the present invention to provide a device for injecting additives into a fluid with a flow divider, which is also applicable to high flow rates.

To this end, the present invention comprises a low flow rate circuit having an inlet with a cross-sectional area smaller than the cross-sectional area of the inlet of the high flow rate circuit, which is coupled to the low flow rate circuit and connected to the high flow rate circuit. It has a chamber partitioned by a diaphragm, and the high flow rate circuit has a sheet facing the diaphragm, and the change in the diaphragm caused by the pressure drop that occurs in one circuit is used to increase the flow rate in the other circuit. This device is equipped with a flow rate divider that controls the flow rate of the two circuits to maintain a constant flow rate ratio between the two circuits.

The invention will be explained in more detail in the following description with reference to the accompanying drawings.

FIG. 1 shows an inlet 1 for the liquid stream to be supplied, which is connected to a low flow rate circuit 2 with an inlet s of small cross-section and a high flow rate circuit 2 with an inlet S of large cross-section. connected to divide the fluid flow rate into a fixed ratio.

The low flow rate circuit 2 comprises means for generating a variable pressure drop, in particular a pump 4 for varying the flow rate.

Furthermore, the device has an enclosure 5 divided into two chambers 5a, 5b separated by a diaphragm 6.

The first chamber 5a has an inlet s toward the upstream side of the pump 4.
It is connected to the low flow rate circuit 2 via a conduit 7 of smaller cross-sectional area, while the second chamber 5b is connected to the inlet 3a and outlet 3b of the high flow rate circuit 3. There is a sheet 8 at the mouth of the outlet 3b, and the diaphragm 6 moves towards the sheet 8 under the action of a differential pressure acting on both sides of the diaphragm in the two chambers 5a, 5b.

Conduit 2b of circuit 2 is connected downstream of pump 4 to conduit 3b of high flow rate circuit 3.

The operation of the device of the invention is as follows.

Liquid is forced through the circuit (not shown) by means such as, for example, a common pump.

When the pressure in the two circuits 2 and 3 is equal, this pressure is equal on either side of the diaphragm 6 and the fluid flows in proportion to the cross-sectional area of the ports s and S.

When the additive is now injected by the pump 4, a pressure drop occurs with respect to the main fluid stream, and the circuit 3,
The relative pressure in circuit 2, 2a and chamber 5a with respect to the pressure in chamber 3a and chamber 5b increases.

As a result, the diaphragm 6 deforms as shown by the dashed line and approaches the seat 8, increasing the pressure in the circuits 3, 3a and limiting the high flow rate, thereby reducing the pressure in the chambers 5a and 5b. Balance, circuit 2 and circuit 3
The flow rate ratio with S is again made proportional to the cross-sectional area of the inlet and S.

Therefore, even with various changes in the low flow rate circuit 2, the flow rate in the circuit 3 is changed in response to the change in the flow rate in the circuit 2 so that the flow rate ratio between the circuit 2 and the circuit 3 is kept constant. change automatically.

2 and 3 are composed of two members 9, 9a fixed to each other by screws,
2 shows an embodiment of the flow divider in which the ends forming the joint of the diaphragm 6 are fixed.

The liquid inlet 1 reaches the member 9a via a chamber 11, which is connected on the one hand to the conduit 2a of the low flow rate circuit via a port 12, which is an inlet s of small cross-section, and on the other hand to the same It is connected to the chamber 5b of the circuit 3 via a port 13 having a plurality of ports having a cross-sectional area S and having a cross-sectional area S as a whole.

A sheet 8 is provided in the chamber 5b and the member 9a, and this sheet is connected to the conduit 2 of the low flow rate circuit 2.
It is arranged around the outlet pipe 3b communicating with the outlet pipe 3b.

A communication pipe 7 with a small cross-sectional area is provided between the conduit 2a and the chamber 5a.

As can be seen from the above, the device of the present invention can handle not only the pressure drop caused by injecting additives, but also the various changes in backflow that occur in the low flow rate circuit. The flow rate ratio of the flow rate circuit can always be kept constant.

[Brief explanation of the drawing]

FIG. 1 is a diagram of the flow divider of the present invention, FIG. 2 is a sectional view of one embodiment of the flow divider described above, and FIG. 3 is a 90° rotation of the flow divider shown in FIG. This is an external view.

Claims (1)

[Scope of Claims] 1. A device for injecting a small proportion of additive into a fluid, which is equipped with a flow divider, wherein the flow divider connects an inlet S to a high flow rate circuit and an inlet S to a low flow rate circuit. an inlet and an outlet pipe in which the high flow rate circuit communicates with a first chamber having an inlet s with a cross section smaller than S, the flow divider being connected to the low flow rate circuit by a conduit; a second chamber having a flow rate divider having a diaphragm separating the first chamber and the second chamber; the shape of the seat, having means for generating a pressure drop to generate a loss, the outlet tube controlling the outflow area from the second chamber by the position of the diaphragm, which is determined according to the pressure difference on both sides of the diaphragm; and
The two circuits are joined downstream of the pressure drop generating means and the second chamber, and the pressure drop generated in the low flow rate circuit controls the flow rate of the other circuit to maintain a constant flow rate ratio of the two circuits. A device for injecting small proportions of additives with a flow divider, characterized in that it maintains 2. The body of the flow divider has one inlet s to the low flow rate circuit and the inlet s to the high flow rate circuit.
2. The device according to claim 1, further comprising an inlet opening into the second chamber and having a plurality of openings having the same cross-sectional area as the inlet. 3. The first chamber and the low flow rate circuit are communicated with each other through a conduit having a smaller cross-sectional area than the inlet s to the low flow rate circuit. Device.