Purpose of the float chamber in the fuel dispenser. Installation of fuel dispensing equipment. Characteristics of fuel dispensers

Fuel dispensers are devices designed for refueling cars. Vehicle quality fuel and accounting for the amount issued. They are classified according to the following criteria:

■ according to the degree of mobility (portable, stationary);

■ by type of drive (manual, electric, combined);

■ by control method (manual, from a local master device, from a remote master device, from an automatic master device);

■ by the number of loading posts (single-post, multi-post);

■ according to nominal fuel consumption (25, 40, 50, 100, 160 l/min);

■ according to the main error (±0.25-0.4%);

■ by type of reading device (mechanical, electrical), etc.

The domestic industry has produced and continues to produce fuel dispensers following types:

KER - stationary dispenser with electric drive and manual control;

KEK - stationary dispenser with electric drive and combined (i.e., remote and manual) control;

Stationary pedcolumn with electric drive and remote control;

KEM - stationary dispenser with electric drive and local control;

KA - stationary column with an electric drive and an automatic setting device (punched card, breadboards, etc.);

KR is a portable dispenser with manual drive and manual control.

Example of fuel dispenser marking according to GOST 9018:

Assembly units are located in one building. Multi-station fuel dispensers are of the following types: single-fuel, dual-fuel with the ability to simultaneously refuel two cars with one type of fuel with separate accounting fuel dispensed through each dispensing valve (for example, 2KED50-0.25-1/1 t);

• dual-fuel, four-hose with the ability to simultaneously refuel two cars with one or two types of fuel, taking into account the doses dispensed through each dispensing valve (for example, 2KED-50-0.251/2 t);
• three-fuel, six-hose with the ability to simultaneously refuel two cars with one or
• two of three types of fuel, taking into account the doses dispensed through each dispensing valve (for example, 2KED50-0.25-1/4 t).

Regardless of the type and brand, each fuel dispenser consists of a hydraulic system and a reporting mechanism.

The column works as follows. The volume of fuel supplied is set from a remote device, the role of which can be played by a remote control, a computer or cash machine. After removing the dispensing valve and installing it in the neck of the fuel tank of the vehicle, the electric motor of pump 3 is automatically turned on. Under the influence of the vacuum created by the fuel pump, fuel from the tank through the intake valve 1 and filters 2, 4 is supplied to the gas separator 5.

Fundamental technology system fuel dispenser:
1 — intake valve; 2 - filter rough cleaning; 3 - pump; 4 - filter fine cleaning; 5 - gas separator; 6 — float chamber;
7 - check valve; 8 — volume meter; 9 - volumetric counter; 10 — electromagnetic valve; 11 — indicator; 12 — pressure hose;
13 — dispensing valve; 14 - bypass valve

The steam-air mixture separated here is directed to the float chamber 6, from where the air is released into the atmosphere, and the liquid enters the suction line of the pump 3. The main fuel flow is from the gas separator 4 through check valve 7, the volume meter 9, the solenoid valve 10, the indicator 11 and the dispensing hose 12 are supplied to the dispensing valve 13, from which it enters the fuel tank of the vehicle.

The foot valve is a check valve installed at the beginning of the dispensing line inside the tank and serves to prevent fuel from draining from the dispensing line back into the tank when the fuel dispenser pump is turned off (thereby ensuring constant filling of the dispensing line with fuel).

Receiving valve type KP:
1 - intake; 2 - rod; 3 - body; 4 - washer - load; 5 - valve

It is a poppet-type structure consisting of a body 3, a valve seat and a valve disc 5. The coaxial movement of the valve disc is ensured by a rod 2.

When the fuel dispenser pump is turned on, the check valve plates rise and allow fuel to flow through. When the pump is turned off, under the influence of gravity and the weight of the liquid column, the plates fall onto the sockets and prevent fuel from draining from the dispensing pipeline.

The coarse filter installed in the suction pipeline is designed to protect the hydraulic system of the dispensers from the ingress of solid particles, which can lead to wear and damage to the pump, as well as to inaccurate measurement of the amount of oil product.

Housing 2 contains a filter element 1 and a check valve 3. The coarse filter ensures the separation of particles larger than 80-100 microns.

Coarse filter:
1 - filter element; 2 - body; 3 - check valve

Fuel dispenser pumps can be various designs. Most widespread received rotary vane type pumps.

Their main elements are the body 3, the rotor 18 and the covers 2, 4.

The blades 19 move freely in the radial grooves of the rotor. During its rotation, under the influence of centrifugal force, they are pressed against inner surface chambers of the pump housing, forming closed volumes, and transfer fuel from the suction cavity to the discharge cavity. Thanks to the installation between the suction and discharge cavities of the bypass valve 14 this type The pump has self-regulating properties. The valve opens if the pressure in the discharge cavity exceeds 0.15-0.18 MPa, and the pump begins to partially work “on itself”. When the pressure reaches 0.25-0.3 MPa, the pump works completely on itself.

Rotary vane pump:
1,2, 4 - covers; 3 - body; 5, 7,8 — bushings; 9 - spring; 10 - nut; 11 - pulley; 12 — special washer; 13 - plug;
14 - gasket; 15 — adjusting screw; 16 - spring; 17 - valve; 18 - rotor; 19 - shoulder blade; 20 - fitting

Recently, some fuel dispensers have used submersible pumps. In this case, the formation of steam-air plugs in the suction pipeline does not interfere with the operation of the columns.

The fuel dispenser gas separator is designed to separate air from the fuel, which may get into it when fuel is drained into tanks, as well as due to leaks in the suction pipeline.

It is a cylindrical body 2, inside of which there is a filter element 4. A fitting is screwed into the cover 10 for connecting a tube through which the steam-air mixture is discharged into the float chamber.

The float chamber consists of a body closed with a lid 4, in which there is a float 3, rigidly connected to the needle valve 1. The two-phase mixture that enters the float chamber is separated in it under the influence of gravity. When the liquid level in the chamber becomes sufficient, the float 3 floats up and the needle valve 1 opens, due to which the fuel returns to the suction line.

Gas separator:
1 - plug; 2 - body; 3 - tube;
4 - filter element; 5 — body;
6 - springs on; 7 - gasket; 8 - screw;
9 — bushing; 10 - cover; 11 - ring

Float chamber:
1—needle valve;
2— body; 3 — float; 4 - cover

Solenoid valve membrane type designed to reduce fuel consumption before the end of dose dispensing and stop fuel supply after dispensing a given dose. Since it performs two functions at once, it is called a double-acting valve.

Double acting solenoid valve:
1 - electromagnets; 2 - jet; 3 - cover; 4 — body; 5 - main valve;
6 - membrane; 7 - jet; 8 — anchor; 9 - rubber seals

The volume meter is a four-cylinder hydraulic motor, the cylinders of which are cast in a common block. The cylinders contain slides with pistons sealed with cuffs, which are pressed against the cylinders by special spiral springs. With the help of a spool, the fuel flow is directed alternately to each of the cylinders, moving the pistons from one extreme position to another. Forward movement the rocker with pistons is converted into rotational movement of the crankshaft, which is transmitted to a flow sensor with remote fuel. The stroke of the scenes with the pistons is adjusted by adjusting screws.

The reading mechanism of the meter is an indicator of the volume of one-time dispensing and the total volume of fuel that has passed through the liquid meter. It is driven by the rotation of the liquid meter shaft.

The indicator is used for visual definition presence of air in the supplied fuel. It consists of a body, o-ring 3, gaskets 2 and transparent petrol-resistant cup 1.

Indicator:
1 — petrol-resistant cup; 2 - gasket; 3 - sealing ring

The dispensing hose is designed for refueling equipment. The oil and petrol resistant hose has a length of 3.5-4 m. One end of it is connected to the indicator pipe, and the other to a dispensing valve with a shut-off valve. The sleeve is grounded by a wire passed inside.

The dispensing valve can be automatic or non-automatic (manually controlled). The latter consists of a housing, a connecting device (with a drain pipe sleeve), a working valve with a control lever and a shut-off valve (since the “full hose” system has been adopted all over the world for fuel dispensing equipment at gas stations, i.e. the hydraulic system must be completely filled with fuel) .

Manual taps are opened by pressing a special lever. Accordingly, to close them, the lever must be lowered. In automatic taps, when the fuel tank is filled to the top level, closure occurs automatically. This is convenient and prevents overfilling, but when used, due to air leaks, foam forms on the surface of the fuel in the tank, which leads to premature operation of the shutdown mechanism.

Main characteristics of fuel dispensers

The dispenser is installed on a foundation, which provides for the possibility of laying from 1 to 4 (depending on the modification of the dispenser) suction pipelines and one pipeline each for power and control cables.

The diameter of the suction pipelines is 4050 mm, their installation depth is at least 0.7 m, the slope is 1-3 degrees towards the tanks.

Dispensers must be installed at a distance of no less than 5 and no more than 18 m from the tanks with a height of the vertical section of the suction pipelines of up to 4 m.

Each fuel dispenser, regardless of its general design, comprises:

Rotating fuel pump electric motor;

Coarse filter installed on the suction pipe of the pump;

A gas separator installed after the pump on the discharge line;

A device for reducing flow at the end of dose delivery, which is usually installed after the gas separator;

Volume meter for ordering a dose;

A dispensing hose with a valve, an indicator in front of the dispensing hose or a dispensing tap to control the quality of the dispensed fuel (the absence of air bubbles in the fuel is checked);

A reading device connected to a volume meter to display information about the amount of fuel dispensed and a device that drives the column.

Basic hydraulic diagram of the fuel dispenser:

Designation:

1 - intake valve; 2 - counter with flow sensor; 3 - volume meter; 4 - solenoid valve; 5 - pressure hose; 6 - indicator; 7 - dispensing valve; 8 - pump monoblock; 9 - coarse filter; 10 - pump; 11 - fine filter; 12 - gas separator; 13 - float chamber.

Modern gas stations use a fuel dispensing system to control fuel dispensers, which includes: system unit computer, display, keyboard and cash register. The fuel supply system sets the dose.

When the dispensing valve is removed, the electric motor turns on automatically. Under the influence of the vacuum created by the pump, fuel from the tank enters the pump through the receiving valve. The pump supplies fuel to the gas separator. Through the valve and volume meter, the measured fuel flows through the dispensing valve into the consumer tank. When fuel enters the gas separator, the flow rate decreases sharply due to an increase in the through-flow of liquid, as a result of which the most complete release of fuel vapor and air occurs from the fuel, both with small and significant suction.

Fuel from the gas separator enters the volume meter. Filling the cylinders, fuel sets the pistons in motion, which move from one extreme position to another. The translational movement of the piston, together with the linkage on which it is rigidly fixed, is converted into rotational movement of the shaft, and in one stroke of the piston the crankshaft and spool rotate 180°. Rotation of the crankshaft with a spool makes it possible to fill each of the four cylinders in turn, while fuel is simultaneously forced out of the opposite cylinder (two pistons are fixed on one rocker). Rotational movement crankshaft volume meter is transmitted through coupling onto the fuel flow sensor shaft.

The pump receives rotational motion through a V-belt transmission from an electric motor.

In order to reduce hydraulic losses and reduce the dimensions of the hydraulic system of the dispensers, there is currently a tendency to combine a number of hydraulic system units into one unit (monoblock), in which the functions of the units being combined are performed by separate chambers of the monoblock. As a rule, a pump, filters, a gas separator, a float chamber, and a pump operation valve are combined into a monoblock. In this case, the volume meter and electric motor are mounted directly on the monoblock.

Dispenser fuel pumps can be of various designs. The most widely used pumps are the rotary vane type.

Some foreign manufacturers of fuel dispensers use multi-stage submersible pumps, which are installed separately from the fuel dispenser inside fuel tanks on the suction lines of the dispensers. Such pumps can serve either one column or several. An example of such columns are the columns of the Tokheim (USA) and Dresser Wayne (Sweden) corporations. Fuel pumps must have safety valves, ensuring constant fuel pressure in the discharge line, and bypass line for fuel in case the fuel dispenser is turned on when the fuel dispensing valve is closed.

Coarse filters are designed to protect the hydraulic system of the dispensers from the ingress of foreign solid particles of large size (more than 80-100 microns), which can lead to wear and damage to the pump and volume meter.

A fine filter is also installed on the dispensers in order to provide consumers with fuel purified to a certain extent (usually up to 20 microns). Filters use either meshes or a variety of filter materials.

Gas separators fuel dispensers are designed to separate air from the fuel, which can get into it when draining fuel into tanks, as well as into the suction pipeline during operation fuel pump columns. In most cases, the separation of air from fuel in gas separators occurs due to sharp decrease fuel flow rate by passing it through a sharply expanding pipeline. There are designs of gas separators for dispensers in which gas separation is carried out by twisting the fuel flow in the pipeline along a helical line. In this case, the liquid phase of the fuel, being heavier, is pressed against the walls of the pipeline by centrifugal forces, and the gas phase moves along central axis pipeline, is taken through a special hole and removed from the pipeline. An example of such a gas separator is the gas separators of columns from Bennett (USA).

The steam-air mixture from the gas separator usually enters a special column assembly called the float chamber, where some condensation of fuel vapor occurs, deposition of fuel particles carried along with the steam-air mixture and release of the released air and vapor into the atmosphere. The liquid fuel deposited in the float chamber, as the chamber fills, raises a special float, which opens a hole in the bottom of the chamber and releases the fuel into the suction pipeline of the dispenser. At the end of the release liquid fuel from the chamber, the hole closes and the operation of the float chamber continues.

Typically, after the gas separator, a device is installed in the hydraulic system of fuel dispensers to reduce the flow rate at the end of dose dispensing in order to complete the operation of the dispenser at a low flow rate, which significantly increases the accuracy of dose dispensing. Such devices are usually installed solenoid valves single or double action. Single-acting valves only reduce fuel consumption at the end of the dose. Double-acting valves additionally completely shut off the pipeline after the dose is dispensed. Commands to reduce flow and completely shut off the pipeline to the valves are given by the column control system, turning on or off the valve electromagnets. In existing dispensers, the interval between the command to reduce consumption and the end of dispensing a dose of fuel ranges from 0.4 to 1 liter.

Volume meter designed to measure the amount of fuel dispensed. As a rule, the amount of fuel in a fuel dispenser is measured in units of volume. Some manufacturers of fuel dispensers are making attempts to measure the amount of fuel dispensed in units of mass. But this is not yet widely used in fuel dispensers due to the significant complexity of their design.

The method of measuring the amount of fuel in units of volume is the simplest, but it requires the introduction of corrections for the volumetric change in the amount of fuel depending on changes in temperature. This is done either structural elements in a column, or by recalculation using special tables. Columns typically use compacted type volume meters. These are basically piston volume meters, in which the measuring elements are cylinders from which fuel is pushed out by pistons. The flow distribution among the pistons is carried out using special spools. The moving pistons rotate the crankshaft, to the output end of which a reading device is connected, which provides digital information about the amount of fuel dispensed.

Reading devices can be of various designs: mechanical pointer, mechanical roller, electro-mechanical, electronic. They can display information only about the size of the dispensed dose or, in addition to this information, also information about the price of one liter of fuel and the cost of the dispensed dose. All mechanical reading devices also display information about the total amount of fuel dispensed by the dispenser since its installation at the gas station.

Reading devices mechanical type are installed on the output shaft of the volume meter, or have some kind of mechanical connection with it. Reading devices of electromechanical and electronic types are installed independently of volume meters. When using electromechanical and electronic reading devices, an additional unit is introduced - a pulse sensor, which is installed on the output shaft of the volume meter and gives electrical impulses to the electronic reading device, converting each revolution of the output shaft into a strictly defined number of pulses. And since a strictly defined amount of fuel is dispensed for one revolution of the volume meter (depending on the design - 0.5 l or 1 l), the reading device, depending on the number of pulses received, displays information about the amount of fuel dispensed in liters. The same values ​​in liters are also sent to the remote control. remote control columns. A column with electronic reading devices has a significantly more opportunity for automation technological processes at gas stations than dispensers with mechanical reading devices.

In the hydraulic dispenser system, an indicator with a glass cap or window is usually installed before the outlet of the dispensing hose or dispensing valve, through which you can observe the flow of fuel leaving the dispenser and monitor its gas content. If air bubbles in the fuel are detected in the indicator, the operation of the column must be stopped, since this indicates a violation of the suction pipeline, due to which a large amount of air is sucked in along with the fuel, which the gas separator of the column can no longer cope with. The suction pipeline needs to be repaired.

Dispensing sleeves columns are usually made of rubber fabric. Recently, sleeves from polymer materials. The operation of the dispensing hoses is carried out in difficult conditions. They often become bent, twisted, or exposed to petroleum products. They may be hit by the wheels of refueling vehicles. Therefore, it is necessary to pay special attention to the quality of the hoses installed on the speakers.

At the output ends of the dispensing hoses there are installed dispensing taps. They can be automatic or non-automatic. The taps have outlet pipes (spouts) with which they are inserted into the fuel tanks of the vehicles being refueled. The tap is opened manually by pressing special levers. Depending on the force of pressure on the lever, the degree of opening of the tap is adjusted. In automatic taps, when the fuel tank is filled to the top level, when the fuel reaches the tap pipe, it automatic closing.

All the main components described above are combined into 2-3 blocks and arranged in one dispenser housing.

In order to ensure the possibility of dispensing several types of fuel on both sides with one dispenser, multi-sleeve dispensers are used (4, 6, 8 or more sleeves) with independent hydraulic systems, working on their sleeves. Such columns are single units that make it possible to reduce the area required for installing columns.

In addition to the nodes described above, columns may use other additional nodes, depending on the additional tasks performed by the columns. For solutions environmental problems the dispensers are equipped with units for collecting petroleum product vapors emitted from the necks of the fuel tanks of cars when they are refueled. These are special dispensing valves that have additional valves for taking petroleum product vapors from the tank to the dispenser, two-channel (coaxial) dispensing hoses, pumps for pumping vapors from the dispenser to tanks, special valves that balance the flow of fuel and vapors, fire fuses, etc.

In accordance with government building codes Ukraine DBN 360-90 (change No. 10) at gas stations located within settlements, dispensers must be used that are equipped with a breakaway coupling that prevents fuel leakage in the event of the dispenser sleeve being torn off, which may occur when a vehicle leaves the refueling site with the nozzle not pulled out of the fuel tank.

Fuel dispenser design Despite the wide variety of types and designs of dispensers, they contain:

• intake valve;
• monoblock pump with electric drive;
• liquid meter;
• counting device;
• indicator;
• dispensing valve with sleeve

Fuel dispenser diagram

where, 1 - intake valve; 2 - monoblock pump with electric drive; 3 - liquid meter; 4 - counting device; 5 - indicator; 6 - dispensing valve with sleeve; 7 - filter; 8 - pump; 9 - gas separator; 10 - upper check valve.

Reception VALVE at the inlet to the monoblock pump - designed to retain fuel in the suction cavity.

MONOBLOC PUMP includes:

• filter designed to clean fuel from mechanical impurities: for gasoline with a size of more than 100 microns, for diesel fuel- with a size of more than 20 microns;
• pump is rotary vane, rotary piston or vane. Consists of a housing, a rotor and two covers. The direction of rotation of the rotor is indicated by an arrow on the electric motor pulley. During rotation of the rotor, the blades, under the influence of centrifugal force, are pressed against the inner surface of the pump housing chamber, form closed volumes and transfer liquid from the suction cavity to the discharge cavity. Between the suction and discharge cavities there is a bypass valve with an adjusting screw. The valve opens if the pressure in the discharge cavity exceeds 0.15...0.18 MPa, and the pump begins to partially work “on itself”. When the pressure reaches 0.25...0.3 MPa, the pump works completely on its own.

Rotary vane pump

where, 1, 2, 4 - covers; 3 - body; 5, 7, 8 - bushings; 6 - stuffing box; 9 - spring; 10 - nut; 11 - pulley; 12 - special washer; 13 - plug; 14 - gasket; 15 - adjusting screw; 16 - spring; 17 - valve; 18 - rotor; 19 - blade; 20 - fitting.

• A gas separator with a float chamber is designed to remove gases and vapors from the fuel that interfere precise work liquid meter. In the gas separator, the liquid flow rate is reduced by increasing the flow area, while gas and vapor bubbles are released in the upper part of the gas separator and removed. The gas separator consists of two chambers - the gas separator itself and the float chamber. If necessary, two filter elements with a filter fineness of 20 microns are installed in it. The housing is closed with a lid with a gasket. In its lower part there is a plug for draining fuel when changing filter elements or during repairs. The nozzle hole is connected to a float chamber, in the body of which there is a needle valve that allows the accumulated fuel to drain into the suction cavity of the pump. Air is removed from the chamber through holes in the lid that communicate with the atmosphere.
• Upper check valve installed between the gas separator and the liquid meter. It consists of a body in which the seat is pressed and the valve is installed. The housing is closed by a lid with a sealing gasket. When the column is not working, the valve prevents fuel from flowing back from the measurement system. In addition, the check valve equalizes the pressure when the column is not working and under the influence of external factors in the measuring system is created overpressure. In this case, the pressure through the hole in the valve plate opens it and excess pressure is discharged through the gas separator fitting into the float chamber.

The monoblock pump housing is closed at the ends with covers: rear and front. At the bottom of the rear cover there is a hole for draining remaining fuel during repairs with a plug. The float chamber is closed with a lid.

LIQUID METER. Designed to measure the volume of fuel passing through the column. It consists of a cylinder body, a base, side cylinder covers, and a spool body. The cylinder body is a measuring chamber. It has four cylinders with liners, each of which contains pistons connected in pairs by a link. The pistons are equipped with cuffs. The volume of each cylinder is 125 cm3. The piston stroke is limited by four stops, which regulate the accuracy of fuel measurement. The stops are closed with lids and sealed. Under liquid pressure, the pistons alternately move towards the meter axis, displacing liquid from the opposite cylinder through the spool and pipeline. In this case, the movement of the pistons is transmitted to the cranked and vertical rollers connected to the counting device. The crankshaft is mounted vertically in two sliding bearings. A spool is mounted on its upper part, which, under the influence of rotation of the crankshaft, redistributes the inlet and outlet of fuel. Bottom part The spool is ground into the body, and the top is ground into the seal with the spring. The spool housing shaft is sealed with a cuff. The stroke of the pistons is regulated by changing the gap between the crankshaft crank and the yoke.

The COUNTERING DEVICE is an indicator of the volume of one-time dispensing and the total volume of fuel that passed through the liquid meter. The counting device is driven by rotation of the crankshaft of the liquid meter. For one revolution of the crankshaft, the fluid meter measures the volume of fuel equal to 0.5 liters.

INDICATOR serves to control filling measuring system fuel. The appearance of air bubbles in the indicator indicates deviations in the operating mode of the gas separator or a leak in the suction system.

DISPENSING VALVE WITH SLEEVE is designed for refueling equipment. The hose, 3.5 to 5 meters long, is oil and petrol resistant, one end is connected to the indicator pipe, the other to the dispensing valve with a shut-off valve. The sleeve is grounded with a wire passed inside. The shut-off valve is designed to automatically cut off the fuel flow after the pump stops operating. It is adjusted to a pressure of 0.04-0.06 MPa and prevents fuel from draining from the hose.

To dispense fuel and oils to consumers, fuel dispensers, mixture dispensers and oil dispensers of various designs are used. The main task of the dispensers is to issue specified doses of fuel or oil to consumers with the required accuracy (the dose dispensing error should not exceed ±0.5%).

At gas stations and filling stations, fuel dispensers are mainly used, controlled remotely using special remote controls or using special automated systems, including systems for non-cash distribution of petroleum products.

Despite the variety of designs, all types and models of fuel dispensers have common components and parts. Let's consider the diagram of a fuel dispenser and its principle of operation using the example of a fuel dispenser model 1TK-40 (feed 40 l/min) with an electromechanical control device.

The required amount of fuel is set, and the electric motor 15 of the column is turned on. Under the influence of the vacuum created by the rotary vane pump 3, fuel from the tank flows through the pipeline through the filter 1 and the lower check valve 2, filter 4 into the rotary vane pump. The pump supplies liquid to the gas separator 5, the upper check valve 6, the piston liquid meter 11, the rotary transparent indicator 12, the dispensing hose, the tap 13 and into the car tank.

When liquid enters the gas separator, its flow rate decreases sharply; at the same time, the flow direction changes, as a result of which air and fuel vapors are released from the liquid. Air accumulates in the upper cavity of the gas separator housing and through the nozzle, along with some of the liquid, and the drain tube enters the float chamber, where air and vapors escape into the atmosphere through the air tube, and part of the liquid enters through the drain tube back into the filter. The liquid entering the meter alternately moves the liquid meter pistons connected to the crankshaft and transmitting rotation to it. The crankshaft, in turn, transmits rotation to the counting device 7, which has two dials (front and rear), each of which has one arrow installed, which make one revolution when 100 liters of fuel are released.

The window of the six-drum total counter 8 opens onto the front dial, which shows the cumulative total of the amount of liquid dispensed in liters.

At the end of dispensing a dose of liquid, as can be seen from the arrow indicator, the dispenser automatically turns off the column motor through a pulse from the set pointer 10, and by pressing the reset button 9 the arrow is returned to the zero position.

Hydraulic diagram of fuel dispenser

The principle of operation of the column is explained by a hydraulic diagram. The dose is set on a remote device (remote control, computer or cash register). When the dispensing valve is removed, the electric motor turns on automatically. Under the influence of the vacuum created by the pump, fuel from the tank enters the pump through the receiving valve. The pump supplies fuel to the gas separator. Through the valve and volume meter, the measured amount of fuel flows through the dispensing valve into the consumer’s tank.

When fuel enters the gas separator, the flow rate decreases sharply due to an increase in the flow area of ​​the liquid flow, as a result of which the most complete release of fuel vapor and air occurs from the fuel, both with small and significant suction. Fuel from the gas separator enters the volume meter. Filling the cylinders, fuel sets in motion the pistons, which move from one extreme position to another.

The translational movement of the piston, together with the linkage on which it is rigidly fixed, is converted into rotational movement of the shaft, and during one stroke of the piston, the crankshaft and spool rotate through an angle of 180°. The rotation of the crankshaft with a spool makes it possible to fill each of the four cylinders in turn, while simultaneously displacing fuel from the opposite cylinder (two pistons are fixed on one link). The rotational movement of the crankshaft of the volume meter is transmitted through the coupling to the shaft of the fuel flow sensor.

Characteristics of dispenser components

Let's consider brief description individual units of the hydraulic circuit.

Receiving valve- a check valve installed at the beginning of the dispensing line inside the tank and serving to prevent fuel from draining from the dispensing line back into the tank when the fuel dispenser pump is turned off.

The suction valve is mounted at a distance of 120 - 200 mm from the bottom of the tank, which ensures the flow of pure petroleum product into the dispenser. The valve opens under the influence of vacuum created by the pump in the suction pipeline. When the pump stops operating, the fuel pressure in the pipeline and tank is equalized and the valves 2, under the influence of their own weight, sit on the seats 4.

Filter designed to protect the hydraulic system of the dispensers from the ingress of foreign solid particles, which can lead to wear and damage to the pump and inaccurate measurement of the volume of oil product. There are coarse filters (solid particle size more than 80...100 microns) and fine filters (solid particle size up to 20 microns). Filters use either meshes or a variety of filter materials.

Pump The fuel dispenser is intended for pumping fuel from gas station tanks to car tanks. The most widely used pumps are of the rotary vane (plate) type.

The rotor is located eccentrically relative to the stator, forming a suction and discharge chamber. The rotor has grooves in which the plates (blades) are located. Under the influence of centrifugal forces, the plates move out of the rotor slots. When the volume expands, the process of suction occurs, and when it decreases, injection occurs. The bypass valve maintains a constant pressure in the discharge cavity (for example, 0.2 MPa).

Gas separators fuel dispensers are designed to separate air from the fuel, which can dissolve in it when the fuel is drained into tanks.

IN float chamber condensation of fuel vapor occurs, deposition of fuel particles carried away along with the steam-air mixture, and release of released air and vapor into the atmosphere.

Solenoid valve– a device for reducing the flow rate at the end of dose dispensing in order to complete the column operation at a low flow rate, which significantly increases the accuracy of dose dispensing. There are single or double acting solenoid valves.

Single-acting valves only reduce fuel consumption at the end of the dose. Double-acting valves additionally completely shut off the pipeline after the dose is dispensed.

Volume meter designed to measure the amount of fuel dispensed. A reading device is connected to it, which provides digital information about the amount of fuel dispensed.

Let's consider the principle of operation of a piston fuel volume meter. The translational movement of the piston, together with the linkage on which it is rigidly attached, is converted into rotational movement of the shaft. The rocker (French - groove) has a cutout in which the crankshaft crank moves.

The rotation of the crankshaft with a spool makes it possible to fill each of the four cylinders in turn, while simultaneously displacing fuel from the opposite cylinder (two pistons are fixed on one link). The rotational movement of the crankshaft of the volume meter is transmitted through the coupling to the shaft of the fuel flow sensor.

Reading devices can be of various designs: mechanical pointer, mechanical roller, electronic-mechanical, electronic.

In a hydraulic dispenser system, a indicator with glass cap or a window through which you can observe the flow of fuel leaving the column and control its gas content.

Dispensing sleeves columns are usually made of rubber fabric.

Recently, sleeves made of polymer materials have begun to be used. The operation of dispensing hoses is carried out in difficult conditions; they are often bent, twisted, and can be run over by the wheels of refueled vehicles.

For the convenience of consumers, dispensers are designed with two dispensing hoses operating from one measuring system. In this case, when fuel is dispensed through one hose, the second is blocked by a special valve.

Find wide application designs of dispensers that have two pumping and measuring systems in one housing, operating independently, each with its own dispensing hose. These dispensers can supply two types of fuel. The reading device of such a column is either double or single with locking.

In order to ensure the delivery of several types of fuel from one dispenser, multi-hose dispensers (4 - 6 sleeves) with independent hydraulic systems operating on their own hoses are used. Such columns are solid units, allowing to reduce the area required for installing columns.

At the output ends of the dispensing hoses there are installed dispensing taps or "pistols". They can be automatic or mechanical. The taps have outlet pipes with which they are inserted into the fuel tanks of the vehicles being refueled. The taps are opened manually by pressing special levers. Depending on the force of pressure on the lever, the degree of opening of the tap is adjusted. In automatic taps, when the fuel tank is filled to the top level, when the fuel reaches the tap pipe, it closes automatically. In non-automatic taps, closing is done manually. In this case, there is a risk of overfilling the tank and spilling fuel on the ground, which is undesirable from an environmental and fire safety point of view.

The dispensing valve, which is the closing link of the gas station, must be easy to use, lightweight, without leaking fuel, explosion-proof, beautiful in design and meeting all ergonomic requirements.

Dispensing taps have different Constructive decisions, but perform one function: filling the tank with fuel. Refilling time depends on the tank capacity and liquid flow through the tap. The time spent on refueling one car is assumed to be 3 minutes for gasoline and 5 minutes for diesel fuel.

Types of fuel dispensers

Currently, we are producing domestic dispensers with a flow rate of 50 l/min of the 2000 series, multi-station dispensers of the 4000 series with a flow rate of 50 l/min, columns with an increased flow rate of up to 100 l/min of the 6000 series, multi-station block dispensers with a flow of 50 l/min of the 5000 series .

Series 2000 fuel dispensers are single fuel dispensers with a mechanical or electromechanical fuel meter. Facing elements of fuel dispenser series 2000 (front, rear, side panels) are made of ordinary thin sheet steel, coated with a synthetic primer and enamel. All panels are removable.

The fuel dispenser units are mounted on a frame made of angle steel. Volume meter - 4-piston, made of aluminum alloy with spool valve. Leather cuffs are used to seal the pistons. Reading device: roller type - for the Nara-27M1 dispenser, pointer type - for the Nara-27M1S dispenser, electromechanical type - for the Nara-27M1E dispenser.

The Nara-27M1EN shopping and entertainment complex has a more modern appearance and is equipped with a 5-digit electromechanical display. Engine power - 0.55 kW. Hydraulic part - fuel pump, gas separator, float chamber, coarse filter. The 5 m long dispensing hose can be manual or automatic.

Series 4000 fuel dispensers are characterized by a block-modular layout, in which the information display device and the measuring part are made of separate blocks connected to each other by communications.

6000 series fuel dispensers - high-performance dispensers. An example of such a dispenser is “Nara 61-16”. Distinctive feature Broadcasting dispensers of this series - availability pumping unit with a capacity of 100 l/min, otherwise - units and appearance unified with the 4000 series fuel dispenser. The 6000 series fuel dispenser is recommended for refueling trucks.

Multi-hose modular dispensers of the 5000 series for 1…4 types of fuel provide optimal design options for any gas station.

Mixture dispensers are designed for refueling vehicles with two-stroke engines with a mixture of gasoline and castor oil in various proportions. Such speakers are not produced in Russia. If necessary, pumps from foreign companies are installed at gas stations and filling stations.

Requirements for the technical operation of dispensers and MRKs

Fuel dispensers are designed to measure the volume and dispense fuel when refueling vehicles and into consumer containers. The fuel dispenser accuracy class should be no more than 0.25. Oil dispensers are designed to measure the volume and dispense oils into consumer containers. The accuracy class of the RTO should be no more than 0.5.

Dispensers and MRKs of domestic and imported production must have a certificate of approval of the type of measuring instruments and number State Register measuring instruments. Information about the certificate and State Register number is indicated by the manufacturer in the form (passport) of the column.

Fuel dispensers are means of measuring fuel volume and are subject to state verification:

• primary - upon release from production or after repair;
• periodic - during operation in the prescribed manner.

If the results of the state verification are positive, seals with the imprint of the state verifier are placed in places in accordance with the sealing scheme given in the manufacturer’s operational documentation.

When repairing or adjusting a fuel dispenser or MRK with the removal of the seals of the state verifier, a record of the date, time and readings of the total meter is made in the equipment repair logbook at the time the seals are removed and upon completion of the repair and error adjustment of the fuel dispenser and a petroleum products accounting report is drawn up when performing repair work at the shopping mall (MRK).

In order to avoid mixing of motor fuels when performing operations to verify the dispenser, as well as during control checks of the dispenser error, fuel from the meter is drained into those tanks with which the dispenser operates.

After completing the repair and adjustment of the dispenser or MRK with the removal of the seals of the state verifier, the state verifier is called to carry out their verification and sealing.

In order to prevent spills and spills, gas stations should use fuel dispensers equipped with a dispensing valve that automatically stops dispensing fuel when the vehicle tank is completely filled.

The serial number of the columns (or the sides of the columns) and the brand of the petroleum product dispensed are marked on the dispensers and MRKs. In necessary cases, information about special conditions operation of the device or refueling of vehicles. The dispensers intended for the dispensing of leaded gasoline must bear the inscription: “Leaded gasoline. Poisonous."

Maintenance, repairs, verification of dispensers, MRKs must be recorded in the equipment repair log. In the forms (passports) of dispensers and MRKs, notes are made on the amount of fuel supplied from the beginning of operation, repair and replacement of component parts.

When technical malfunction, lack of petroleum product or in other cases of impossibility of operation of the fuel dispenser (MRK), a sign is hung on it with the inscription “REPAIR”, “MAINTENANCE” or other content informing about its non-operational condition. It is prohibited to twist the distribution hose around the body of a faulty fuel dispenser (MRK). On non-working fuel dispensers and multi-dispenser dispensers, mechanical locking is allowed, which prevents the dispensing valve from being removed from the “socket” on the body.

Operation of fuel dispensers and multi-dispenser dispensers is not permitted:

• with an error exceeding that specified in the type description of this product measurements;