Sulfur compounds of oil. Classification of oil into classes and types.

Petroleum sulfur compounds:

Hydrogen sulfide, mercaptan sulfur, possible presence of elemental sulfur.

Currently, there is a classification of oils according to the GOST R 51858-2002 standard.

Oil by physical and chemical properties, degree of preparation, content of hydrogen sulfide and light mercaptans, oil is divided into classes, types, groups and species.

Depending on the mass fraction of sulfur, oils are divided into classes 1-4:

(1 - low sulfur, up to 0.60%, 2 - sulfur, 0.61-1.80%, 3 - high sulfur, 1.81-3.50%, 4 - especially high sulfur, over 3.50%).

Based on density, and when exported, additionally based on the yield of fractions and mass fraction of paraffin, oil is divided into five types:

0 (extra light), 1 (light), 2 (medium), 3 (heavy), 4 (bituminous).
According to the degree of oil preparation, they are divided into groups 1-3

(mass fraction of water for groups 1-2 no more than 0.5%, group 3 – 1.0%),

According to the concentration of chloride salts, no more than mg/dm3 (1-100, 2-300, 3 – 900).
Based on the mass fraction of hydrogen sulfide and light mercaptans, oils are divided into types 1-3: mass fraction of hydrogen sulfide, no more than ppm, ppm - 1 -20, 2 - 50, 3 - 100 ppm.

Mass fraction of methyl and ethyl mercaptans in total, no more than: 1 - 40, 2 - 60 and 3 -100 ppm.
Example: Oil: mass fraction of sulfur – 1.15% (class 2), density at 15 0C - 860.0 kg/m3 (type 2), concentration of chloride salts – 120 mg/dm3, mass fraction of water – 0.40% (group 2), in the absence of hydrogen sulfide (type 1) - designated “2.2.2.1 GOST 51858-2002”.

Radiation safety measures.

It has been established that Devonian oil is the most radioactive. Large accumulations of oil (reservoirs, settling basins, etc.) have a greater radioactive hazard.

Category B– persons who do not work directly with a source of ionizing radiation, but the workplace conditions may be exposed to radioactive substances emitted into the external environment.

Operators of technical equipment belong to category B personnel; according to the conditions of their workplaces, they may be exposed to radioactive substances. For them, the PD dose limit is indicated highest value individual dose per calendar year in which uniform exposure over 10 years cannot cause changes in health status.

The permissible dose rate is 0.24 microroentgen per hour.

On the territory of production facilities, the boundaries of areas of radiation contamination are determined, which are indicated by radiation safety signs indicating the dose rate of gamma radiation. Contaminated areas must be fenced off.

Before starting any repair or cleaning work technological equipment contaminated with radioactive fallout, all persons involved in repair work or visiting work sites must be instructed and provided with equipment personal protection.

When carrying out work in conditions possible lack oxygen (inside containers, reservoirs...) personnel must be provided by special means respiratory protection (hose gas masks).

When carrying out work with radioactive fallout on outdoors personnel must be provided with respiratory protection, respirators of the ShB-1, ShB-2 type. After use, respirators are disposed of as radioactive waste at the end of each shift.

All repair work on technological equipment must be carried out in special clothing and personal protective equipment, which must be checked for integrity and serviceability before starting work. Special clothing must be made of cotton fabric, rubber shoes, rubberized mittens and a hat are required.

Before starting work that involves opening and cleaning technological equipment, it is mandatory to measure the gamma radiation dose rate on the surface.

After opening any technological equipment, the dose rate of gamma radiation inside the equipment is measured. The measurement results are documented in a special act.

It is not permitted to use tools and devices used for cleaning containers contaminated with radioactive fallout for any other work without decontaminating them and monitoring them for the presence of radiation contamination. These devices must be stored separately from other tools and must have a special label.

Smoking and eating are permitted after radiation monitoring of the cleanliness of hands and other body surfaces, and in specially designated areas.

Upon completion of work, monitoring for radioactive contamination is carried out.

Dispenser pump. Device, principle of operation, marking.

Dispenser pumps are designed to dose the reagent into a device or pipeline.

Classification of dosing pumps

With all their diversity, metering pumps can be divided into two conditional categories:

· depending on the design of the piston - plunger and diaphragm;

· depending on the type of drive - pumps with mechanical and hydraulic drive.

Dosing pumps are characterized by the rate of supply of the dosed liquid, maximum operating pressure, dosing accuracy, type of working chamber (depending on whether it is a plunger or diaphragm pump), type of material from which the working chamber is made

Plunger type dosing pumps.

By the nature of their operation, a plunger pump is classified as a positive displacement pump.

In their design and specifics of operation, plunger pumps are very similar to piston pumps (Fig. 86). The main difference lies in the features of a kind of piston - or plunger. The plunger (Fig. 86a) is a cylindrical displacer, the length of which is much greater than the diameter.

Plunger - main element operation of the plunger pump. That is why a number of special requirements: It must be wear-resistant, sealed and durable, thereby ensuring reliable and quality work pump

Rice. 86. a – single-acting plunger pump, b – piston pump.

The cost of the pump itself directly depends on the materials used to make the plunger: a high-quality pump will have a correspondingly higher cost.

These pumps provide very precise dosing because... both the piston and the working chamber are made of materials that are practically not subject to any mechanical changes during the operation of the pump (with the exception of corrosion processes and mechanical wear of moving parts).

Plunger dosing pumps are usually used:

if it is necessary to create a powerful pressure of the dosed medium (up to 20–30 MPa or more);

if you need to supply a large volume of dosed reagent.

They are designed for volumetric pressure dosing of neutral, aggressive, toxic and harmful liquids, emulsions and suspensions with high kinematic viscosity (about 10–4–10–5 m 2 /s), with a density of up to 2000 kg/m 3. Depending on the type of pump (piston diameter, pump characteristics and number of piston strokes), the flow rate can vary from a few tenths of a milliliter to several thousand liters per hour.

Disadvantages include the presence of moving parts, compared to diaphragm pumps. In addition, it is undesirable to use them for dosing ultrapure solutions due to the possibility of breakaway microparticles of the metal from which the pump is made getting into the solution.

Diaphragm (diaphragm) dosing pumps

In membrane (diaphragm) dosing pumps, the suction and expulsion of a substance from the working chamber occurs due to the forced vibration of the membrane, which is actually one of the walls of the working chamber. The basic design of metering pumps of this type is shown in Fig. 88.

The use of an elastic membrane as a kind of “piston” determines both the advantages and disadvantages of diaphragm pumps.

The advantages include, first of all, the absence of any moving parts in the working chamber, which prevents any mechanical impurities from entering the pumped medium during pump operation. That is why diaphragm-type pumps are used for dosing ultrapure reagents or ultrapure water in the electronics and pharmaceutical industries. The second, undeniable advantage of diaphragm metering pumps is the ability complete production working chamber made of corrosion-resistant materials that can withstand contact with almost any aggressive environment. This advantage of dosing pumps has led to their widespread use in chemical industry. And finally, the absence of “stagnant” zones in the working chamber of the pump allows them to be used to pump liquids containing abrasives (for example, cutting fluids). Therefore, diaphragm metering pumps are among the most popular on the market.

The main disadvantage of membrane metering pumps should be considered not high accuracy dosing (compared to plunger ones). It's connected:

a) with a cycle of membrane oscillations (it is impossible to predict the mode of stretching/compression of the elastomer, especially with changes in the temperature of the pumped medium);
b) with the “fatigue” of the membrane material accumulating over time (the elastomer loses its original characteristics, stretches and, ultimately, not only the dosing accuracy, but also the main characteristics of the pump deteriorate).

Second negative factor the use of metering pumps of this type is again associated with membranes, or rather with their mechanical strength. The impact of any large mechanical inclusions on the surface of the membrane can lead to destruction, and as a result, to loss of tightness of the working chamber.

The third disadvantage is the low productivity of diaphragm pumps and the rather low development operating pressure. This is again due to the use of an elastic membrane as a “piston”.

The MTZ metering pump is an integral part of the hydraulic volumetric complex that controls the tractor. It promotes proper distribution of fluid and its supply to the hydraulic cylinders, which, in turn, greatly simplifies tractor control.

This allows the operator to apply much less effort to turn the wheel, which is very important when the tractor is heavily loaded.

1 What is the operating principle of the MTZ pump?

The MTZ metering pump is produced at the tractor plant in Minsk. The manufacturer has simplified the design of the unit as much as possible to ensure good wear resistance of the mechanisms and ease of maintenance. The unit includes 3 main components:

The oscillating unit of the pump contains several parts: a stationary stator and a rotor, to which the spool of the device fits. The spool is secured by 2 springs and connected to the steering column shaft. While moving, the steering column sets the spool in motion and, moving relative to the central axis, supplies oil inside the pump.

The special valve block of the housing contains anti-vacuum, safety, check and shock valves. Check valves required in case of hydraulic motor failure. Then the valve closes the drain channel of the hydraulic booster system, interfering with the movement of fluid. Safety valves regulate the pressure in the oil piping system.

Anti-vacuum valves help move oil to the hydraulic cylinders during system failures. Shock-proof valves regulate the pressure in the lines under very heavy loads when driving on uneven sections of the road.

The dispenser pump must be installed on equipment moving at a speed of no higher than 50 km/h, and must be located in the volumetric hydraulic drive of the machine.

By influencing the control system, the dispenser pump supplies working fluid to the hydraulic cylinder and enhances the operator’s actions. If there is no influence on the control system, the position of the pump becomes neutral, and it passes liquid directly to the drain system.

2 How to install the metering pump correctly?

When installing a metering pump on MTZ 80 and MTZ 82, the power steering system (hydraulic steering control) is partially replaced with HSC (hydraulic volumetric steering).

The MOUNTAIN kit includes:

If necessary, also buy a crane that blocks the differential of the HSC mechanism. It is used to replace the lock used on the power steering. This crane provides the ability to lock the steering wheel on unstable road sections, which improves vehicle maneuverability.

2.1 Installation algorithm

1. First of all, remove the power steering box (distributor). To do this, you need to remove the control levers, then remove the anther plates, seals and anthers. Then you need to remove the covers and pull out the spools.
2. At the next stage, the bearings are replaced if the existing ones are worn out.
3. Remove the worm of the unit.
4. The dispenser shaft is installed in place of the worm.
5. The dosing device is screwed to the required bar. Countersunk bolts are used for installation.
6. Then the pump is checked and after that the metering pump is installed on the MTZ in the hydraulic booster system.

The rest of the HPS kit is changed before the unit is installed.

2.2 INSTALLING THE UNIT ON MTZ WITH YOUR OWN HANDS (VIDEO)

3 Pump faults

Any malfunction of the dispenser on MTZ 82 or the volumetric steering control system can cause complications in the functioning of the control system. To restore the functionality of the system, a clear understanding of what exactly has become unusable is necessary. This can be judged by the following signs:

Contamination of the hydraulic booster circuit can also cause a malfunction.

If the pump valves become clogged with dirt and other particles, they will not be able to move fluid through the system and regulate pressure. The result will be a decrease in the performance of the system, and it may break.

Pumps batchers in the systems of water treatment

Keywords: pump batcher, water treatment, reagent, station of dispensing, plunger pump

Many processes of water treatment demand use of reagents, actively apply them at the industrial enterprises, in the housing sector, in sports and improving complexes to chemical water treatment of pools. The majority of chemical reagents are active agents, and exact dispensing of these substances generally is required to provide their necessary concentration in the purified water. Pumps batchers, or as they are called still, the dosing pumps are used to these purposes.

Description:

Many water treatment processes require the use of reagents; they are actively used in industrial enterprises, in the housing and communal services sector, in sports and recreation complexes for chemical water treatment of swimming pools. Most chemical reagents are active substances and generally require precise dosing of these substances to ensure their required concentration in the water being treated. For these purposes, dosing pumps are used, or, as they are also called, dosing pumps.

Many water treatment processes require the use of reagents; they are actively used in industrial enterprises, in the housing and communal services sector, and in sports and recreational complexes for cold water pools. Most chemical reagents are active substances and generally require precise dosing of these substances to ensure their required concentration in the water being treated. For these purposes, dosing pumps are used, or, as they are also called, dosing pumps. They are designed for volumetric dosing under pressure of various liquids, as well as emulsions and suspensions.

Metering pumps are used for the following processes in modern systems water treatment:

• dosing of biocide solutions for water disinfection;
• dosing of coagulant solutions before clarifying filters;
• dosing of inhibitors for installations based on reverse osmosis;
• correction of the salt composition of water, control and maintenance of its physical and chemical parameters in a given range for food production and for the heat and power industry;
• dosing of reagents for water disinfection in swimming pools and water parks.

There are various dosing stations available on the market. The main elements of the dosing station are the container that contains the reagents and the dosing pump itself. The required concentration of the chemical reagent solution is prepared in the container. Depending on the required flow ready solution and the pressure in the main network, the necessary metering pump is selected. To automate the work process, a microprocessor controller is included in the dosing stations.

Depending on the purpose of the water treatment system, dosing stations can vary significantly in the accuracy of control and dosing of the reagent.

Accordingly, when choosing a dosing pump for technological process it is necessary to proceed from the following parameters:

• productivity;
• maximum back pressure;
• type of pumped liquid (reagent solution), which is especially important for working with aggressive liquids. In this case, parameters such as viscosity, density, temperature, and the presence of suspended substances should be taken into account;
• type of control system, which may be fully or partially automated. To control the system, sensors can be used to monitor the value pH value pH of active chlorine content, turbidity value, reagent level, etc.

Metering pumps vary depending on the piston design. They come in two types: plunger and diaphragm or membrane.

Depending on the type of drive, there are:

• mechanically driven pumps;
• hydraulic driven pumps.

The dosing pump is a reciprocating type displacement pump, consisting of a drive motor, gearbox and pump head. The gearbox reduces the engine speed by converting rotational motion into reciprocating motion of the piston in the pump head.

Plunger systems are designed to dispense large volumes or create high pressure. Plunger pumps operate on the principle of moving a piston structure, inside which a vacuum or strong pressure is formed. When a vacuum forms in a plunger device that has a dispenser, the system sucks in liquid, and when pumped, it pushes it out. Such pumps can provide high precision dosing. Since in such pumps the pumped reagent solution is in direct contact with the piston, it is necessary to pay special attention to the compatibility of the chamber and piston materials with chemical composition solution.

It is also important to evaluate the abrasive content of the solution, as they can cause additional mechanical wear, which can lead to the pump losing its seal. These pumps are often equipped with mechanical drives.

The design of diaphragm dosing pumps is characterized by the presence of a closed chamber, which is separated from the drive by means of a completely sealed membrane. The pump operation is controlled by a system of valves at the inlet and outlet of the system. This pump design ensures tightness internal space, which prevents the pumped medium from entering the surrounding space. For such pumps, the advantage is that they can be used for particularly chemically aggressive solutions, since it is possible to manufacture the chamber from corrosion-resistant materials. Also, such pumps are capable of pumping solutions containing abrasives.

At the same time, diaphragm pumps, compared to plunger pumps, cannot provide high dosing accuracy. Also, the pressure they develop cannot be high due to design features.

Typically, diaphragm metering pumps use a solenoid drive. A hydraulic drive is used less frequently: it provides higher accuracy of reagent dosing. For chemical water treatment in swimming pools, membrane metering pumps are most often used.

The reagent dosing system for swimming pools should include:

a) container (tank) for working solutions;

b) a device for suction of the working solution from the container;

c) a device for injecting the working solution into the water supply pipeline to the pool;

d) a metering pump connected to suction/injection devices by hoses/tubes made of chemically resistant materials.

The water quality control system should include:

a) sensors for measuring the relevant controlled parameters of water quality, usually placed in a flow cell;

b) sensor for the flow of analyzed water through a cuvette with sensors.

According to GOST R 53491.2–2012 “Pools. Water preparation. Part 2. Safety requirements" "...The quantity and necessity of using reagents for water treatment should be strictly justified not only to ensure the safety of the health of users, but also in relation to environmental protection.”

The material was prepared by N. A. Shonina, teacher at the Moscow Architectural Institute

Reading time: 6 minutes.

The MTZ metering pump is an integral part of the tractor's hydrostatic control system. He is responsible for the correct distribution of fluid in the system and for its supply to the hydraulic cylinders. This strengthens the control system.

In this case, the operator needs significantly less effort to turn the wheels. This point is of particular importance if the tractor is heavily loaded.

Design and principle of operation of the metering pump at MTZ

The MTZ metering pump is manufactured at the Minsk Tractor Plant. The manufacturer has simplified the design of the device as much as possible to ensure high wear resistance of the mechanisms and ease of maintenance. The device consists of three main components:

• a housing equipped with a valve block;
• special swing unit of the device;
• distribution mechanism.

The swing unit of the device consists of several parts. It is represented by a stationary stator and rotor, to which the spool of the device extends. The spool, in turn, is fixed by two springs and connected to the steering column shaft. When the steering column moves, the spool also moves and, moving relative to the central axis, supplies oil inside the device.

The special valve block inside the housing includes anti-vacuum, safety, check and shock valves. System check valves are required in case of hydraulic motor failure. In this case, the valve closes the drain channel of the hydraulic booster system, preventing fluid circulation. Safety valves regulate the pressure inside the oil piping system.

Anti-vacuum valves are responsible for transporting oil inside the hydraulic cylinders in case of an emergency in the system. Shockproof ones regulate the pressure inside the lines under excessive load in case of work on uneven sections of the road.

A dosing pump is installed on equipment whose speed does not exceed 50 km/h. It is located in the volumetric hydraulic drive of the machine.

When influencing the control system, the dosing pump supplies working fluid to the hydraulic cylinders, thereby enhancing the operator's actions. If there is no impact on the control system, the pump is in neutral mode and passes liquid directly to the drain system.

How to properly install the dispenser on the MTZ 82?

Installing a metering pump on MTZ 80 and MTZ 82 involves a partial replacement of the power steering system (hydraulic steering) with a HPS (hydraulic steering) mechanism. The MOUNTAIN kit includes:

• special hydraulic cylinder bracket;
• reinforced steering rod;
• two levers;
• hydraulic cylinders for the front axle with a set of pins;
• dosing pump;
• high pressure channels;
• special adapter for the pump.

If necessary, a differential lock valve for the HPS mechanism is also purchased. It is used to replace the lock that is used on the power steering. Such a crane allows you to block the gearbox on unstable sections of the road, which increases the maneuverability of the equipment.

The dosing device is installed on the machine according to the following algorithm:

1. First of all, you need to remove the power steering system box (also called the distributor). To do this, the control levers are removed. Then the anther plates, anthers and seals are removed. Next, the covers are removed and the spools are pulled out.
2. The next stage is to replace the system bearings with new ones in case of wear of the already installed ones.
3. The worm of the device is removed.
4. The dispenser shaft is installed in place of the worm.
5. We screw the dosing device to the corresponding die. Installation is carried out using countersunk bolts.
6. Next comes checking the pump and after that its installation in the hydraulic booster system.

Replacement of the remaining HPS kit is carried out before installing the pump.

Do-it-yourself installation of a metering pump on MTZ (video)

Malfunctions of the MTZ dispenser pump and their symptoms

Any malfunction of the metering device or the volumetric steering system leads to complications in the operation of the control system. To restore the functionality of the system, you should clearly know which node has failed. There are a number of signs for this:

1. The front axle has become more unstable. This symptom in most cases indicates a displacement of the axis of the rotary shaft. It is also possible for gaps to form in the steering linkage or pump components.
2. Turning the steering wheel has become more difficult and requires additional effort. The reason is that there is not enough oil inside the dispenser. The second option is a large amount of air inside hydraulic system and, as a result, the device is partially idle.
3. Willful change in the position of the steering wheel. Self-turning of the steering wheel is a consequence of the incorrect position of the spool inside the pump. Two tension springs are responsible for its neutral position. If one of them breaks down, oil is constantly supplied to one of the cylinders, and the steering wheel turns accordingly.
4. Weak support during turning or its complete absence. This phenomenon occurs when there is not enough oil in the dispenser. Accordingly, its functionality decreases. The second cause of the problem may be abrasion of the sealing gaskets on the cylinders responsible for turning the machine.
5. When you turn the steering wheel, the tractor wheels turn in the opposite direction. In this case, the problem is that the leads to the machine's hydraulic cylinders are not connected correctly to the metering pump. As a result, the spool supplies oil to the wrong cylinder, and accordingly the wrong side is strengthened.

Also, one of the problems in the operation of the pumping equipment of the hydraulic booster circuit is its contamination. When the valves of the device become clogged with dirt and other particles, they are unable to pass fluid through the system and regulate pressure. As a result, the functionality of the system is reduced and its breakdown is possible.

Device maintenance

Since the pump is not completely protected from dirt entering the system, it may become clogged. As a result, it must be washed periodically to prevent serious damage.

This event is carried out after complete disassembly of the device. The pump must be washed with kerosene or a liquid with similar properties. Before you start washing, you must remove the rubber sealing rings from all parts. This will prevent them from being damaged. Each part is washed individually and very carefully. Special attention should be given to the two bushings of the device. They are equipped with a series of small holes that get clogged quickly.

After all the parts are washed, the device is assembled in the reverse order. Here important point is correct installation gerotor pair and distributor leaf spring. The first part should be installed with the pump facing the holes away from you. The pair is installed in such a way that two teeth are located on a line in front of the master.