RU31153U1 - Diaphragm hydraulic metering pump - Google Patents

Description

Diaphragm Inductive Injection Pump

The utility model is intended for use in technological processes of the chemical, oil refining, heat power and other industries for volumetric pressure dosing of neutral, aggressive, toxic and harmful liquids, emulsions and suspensions.

A known hydraulic diaphragm metering pump comprising a drive, a housing with a diaphragm separator of the drive and pump chambers installed therein, a make-up valve, a displacer made in the form of a sealed plunger, a reservoir for supplying a drive fluid equipped with a filter and an air separator, (RU 16527 U1, 10.01. 2001).

Significant disadvantages of the prototype are the installation site of the make-up valve and the design of the air separator.

The operability of any hydraulic diaphragm pump depends on the presence of an air pump in the drive chamber of the drive fluid, since compressible air compensates for the change in the volume of the drive chamber, reducing the flow of the pumped product up to its complete disruption, which is especially evident in pumps in the feed range up to 16 liters per hour because the feed in one stroke of the plunger is from tenths to units of cubic centimeters. The air in the drive chamber may remain after filling it with the drive fluid before starting the pump, and air may also enter the drive chamber through the plunger seals from the atmosphere and be released from the drive fluid at the suction stroke when a discharge occurs in the drive fluid.

The installation of the prototype make-up valve in the tank with the drive fluid entailed two negative results. Firstly, the complexity of servicing the valve, since in order to get to it

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the result - the valve was installed at the upper point of the drive chamber, which prevents the correct, that is, complete filling of the drive chamber drive fluid. In the place of installation of the make-up valve, a cavity will inevitably form in which air will linger, not being able to freely float to the air separator, which can cause the pump to become completely inoperative, especially if a single supply is less than a cubic centimeter.

The design of the prototype air separator has two significant drawbacks that seriously affect its performance, and, consequently, the performance of the pump. The first and most significant drawback is the implementation of the working edge of the lower saddle directly in the fitting at the bottom of the socket under the nozzle of the air separator. Due to the fact that the pump has small feeds, in order to minimize leaks through the air separator, it is necessary to carry out structural elements of a two-seat ball valve of small geometric dimensions. It is practically impossible to make a small lower saddle at the bottom of a deep nest in a fitting with the required quality. By the required quality is meant that the edge of the channel of the saddle must be made so that the ball, sitting on it, hermetically overlaps the channel. In addition, this design, due to the inaccessibility of the lower saddle, makes maintenance of the air separator as difficult as possible - it is easier to replace than to repair. The second drawback of the design is the use of an o-ring as an element restricting the ball in the two-seat valve. The use of the ring makes it impossible to accurately set the value of the ball stroke, since being elastic, it is deformed by the force arising when the nozzle is twisted into the nozzle, which is very important, given that the ball stroke is not more than two - two and a half millimeters. Inability to accurately set the ball stroke

It doesn’t allow you to precisely limit emissions of the drive fluid - you can either pinch the ball or leave too much travel.

The technical task set in the present; a useful model for it is to increase the reliability of the pump, by completely removing air from the drive chamber.

This task is achieved by the fact that in the membrane hydraulic metering dosing pump, it contains a drive, a housing with a membrane separator of the drive and pump chambers installed in it, a make-up valve, an air separator, a displacer, made in the form of a sealed plunger, a reservoir for supplying the drive fluid, equipped with a filter , the make-up valve is installed in the lower part of the housing and is connected to the drive chamber and the reservoir for supplying the drive fluid with channels, and the air separator is made in the form of a fitting screwed into the housing, in the torus has a saddle and a bore sealed with elastic rings, a spacer sleeve and a ball fixed by a bore, a saddle is made at the lower end of the bore, the bore is equipped with a tube, the lower end of which is installed in the upper part of the bore, and the nozzle is installed on the upper end for threading , and inside the tube is spread; a needle is inserted, resting on the ball with the lower end and protruding from the nozzle with the upper end;

In FIG. 1 shows a general view of a diaphragm hydraulic drive pump; FIG. 2 shows an air trap.

The pump contains a drive (not shown in the drawing), a housing 1, a flange 2, between which the membrane separator 3 is clamped, dividing the inner cavity of the membrane pump into the drive 4 and pump chamber 5. The pump chamber 5 through the suction 6 and discharge 7 valves is connected to the suction and discharge lines. The drive chamber 4 is connected through a make-up valve 8 to a tube 9 with a capacity 10 for a supply of drive fluid and a channel 11 in the housing 1 with installed in the tank 10

air separator 12, made in the form of a two-seat valve. A filter is installed in the container 10 (not shown in the drawing). The make-up valve is removed from the tank 10 and installed in the lower part of the housing 1. The air separator 12 is made in the form of a fitting 13 screwed into the housing 1, in which the saddle 14 of the passage 15 with ring elastic seals 16, the spacer sleeve 17 and the ball 18 fixed by the passage 15 are installed. 15 is provided with a tube 19, the lower end of which is installed in its upper part, and a nozzle 20 is installed using the thread on the upper end of the tube 19. A needle 21 is placed inside the tube 19, resting on the ball 18 with its lower end and its upper end protruding from the nozzle 20.

The pump operates as follows.

During the reciprocating movement of the plunger, the membrane separator 3 makes a similar movement, as a result of which the volumes of the drive 4 and pump 5 chambers are periodically changed, the pumped medium is sucked into the chamber 5 through the suction valve 6 and forced out through the discharge valve 7 into the discharge line.

At the suction stroke, when pressure drops in the drive oil, dissolved air begins to be released from it. Air can also enter the drive chamber from the atmosphere through the seal of the plunger. The presence of air in the drive chamber leads to a decrease in the metering accuracy, since compressible air compensates for part of the plunger stroke, decreasing the oscillation amplitude of the membrane separator 3, and, therefore, reducing the change in the volume of the pump chamber 5.

An air separator 12 is used to remove air from the oil filling the drive chamber. The air separator operates as follows. Since the air trap socket is at its highest point

4 drive chambers 4, then the whole appeared during the suction stroke

air accumulates under the ball 18, which during the suction stroke is pressed by the pressure drop between the atmosphere and the drive chamber 4 to the lower seat 14, cutting off the drive chamber 4 from the tank 10. At the beginning of the pumping stroke, the discharge pressure lifts the ball 18 from the seat and pushes the accumulated air through the nozzle channel 13, between the ball 18 and the wall of the spacer sleeve 17, through the gap between the spoke 21 and the wall of the channel of the bushing 15 into the tube 19 and then through the tube 19 and the nozzle 20 into the container 10. Further, the hydrodynamic effect of the oil presses rick 18 to the upper saddle, made at the end of the bore 15, cutting off the drive chamber from the atmosphere. During the discharge stroke, the discharge pressure holds the ball 18 pressed against the upper seat.

At the beginning of the suction stroke, the ball 18 under the influence of the gravity of the spokes 21 and the hydrodynamic effect of the oil lowers onto the lower seat 14 in the fitting 13 and, pressed to it by the pressure drop between the atmosphere and the drive chamber 4, blocks the channel in the fitting 13.

The spoke 21 at the beginning of the injection stroke with its weight for some time keeps the ball 18 from landing on the upper seat, providing complete removal of air from the drive oil. In this case, a small amount of oil is ejected from the drive chamber 4. In the nozzle 20, the ejected oil is formed into a thin stream, visible through the transparent cap of the lid of the tank 10, which allows you to control the operation of the air separator. Emissions of a small amount of oil guarantee complete removal of air from the drive chamber, which eliminates the loss of part of the stroke of the plunger to compress the air. The presence of air bubbles in the discharge indicates the depressurization of the drive chamber.

During operation, oil is leaking from the drive chamber through the air trap 12 and through the plunger seal assembly. Therefore, the volume of fluid supplied to the injection line is slightly less than the volume.

displaced by the plunger. As a result, the deflection of the membrane separator 3 towards the drive chamber 4 at the end of the suction stroke gradually increases, and then the membrane separator 3 lies on the profiled surface of the housing 1. As a result, with a further movement of the plunger to the left, the vacuum in the drive chamber 4 increases. The increasing pressure difference between the drive chamber 4 and the atmosphere acts on the shutter of the make-up valve 8. The valve opens and the drive chamber 4 is connected to the tank 10. Oil from the tank 10 enters the drive chamber 4, making up for leaks. At the beginning of the injection stroke, the pressure in the drive chamber 4 increases and the shutter closes the make-up valve 8 under the action of the spring, cutting off the drive chamber 4 from the tank 10.

As a result of using the claimed utility model, the reliability of the pump and the accuracy of dosing are significantly increased.

Claims (1)

Hydraulic diaphragm metering pump containing a drive, a housing with a diaphragm separator for the drive and pump chambers installed in it, a displacer made in the form of a sealed plunger, a reservoir for supplying drive fluid with a filter, a make-up valve and an air separator, characterized in that the make-up valve is installed in the lower part of the housing and is connected to the drive chamber and the reservoir for supplying the drive fluid with channels, and the air separator is made in the form of a fitting screwed into the housing, in which a saddle and an aisle are sealed, sealed with elastic rings, a spacer sleeve and a ball fixed by an aisle, on the lower end of which a saddle is made, the aisle is equipped with a tube, a nozzle is installed on its upper end, and a needle is placed inside the tube, resting on the ball with its lower end and protruding from the nozzle.