Yu.V. Gornev ( CEO LLC "Vistaros")

It is fairly well known that 60 to 75 percent of the energy consumption of sewage treatment plants (WWTPs) in cities and large industrial enterprises account for the air supply to the aeration system. This article discusses the issues of possible savings in energy consumption in the aeration system through the use of energy-efficient elements of the system.

Reserves for saving energy consumption in the WWTP aeration system are huge, they can be 70% or more. Consider the main elements of this system, which significantly affect energy consumption. If we omit such issues as the need to maintain air supply pipelines, etc. in good working order, then these include:

1. Availability of primary settling tanks at WWTP, which allow to reduce Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) of effluents at the inlet of aerotanks. As a rule, primary settling tanks are already present at most large WWTPs.
2. Implementation of the nitrification-denitrification process, which allows increasing the amount of dissolved oxygen in the return activated sludge. This process is increasingly being introduced in the construction and reconstruction of WWTP.
3. Timely maintenance and replacement of aerators.
4. Application of controlled blowers optimal power, the introduction of a single control system for all blowers.
5. The use of specialized controlled valves in the air distribution system for aerotanks.
6. Introduction of a control system for each valve and all valves based on data from dissolved oxygen sensors installed in aeration pools.
7. Application of air flow meters to stabilize the air distribution process and optimize the set point for the minimum level of dissolved oxygen for the valve control system.
8. Introduction to the control system of additional feedback on the ammonium sensor at the outlet of the aerotanks (used in certain cases).

The first two items (primary clarifiers and the introduction of nitrification-denitrification) refer to more to the issues of capital construction at the WWTP and are not considered in detail in this article. Below we consider the issues of introducing modern high-tech modules and systems that make it possible to achieve a significant reduction in electricity consumption at the WWTP. These modules and systems can be implemented both in parallel with the solution of the first two points, and independently of them.

Blowers are the main consumer of electricity in the aeration air supply system. Them right choice is the basis of energy saving. Without this, all other elements of the system will not give the desired effect. However, we will not start with blowers, but will follow the order in which it is necessary to select all modules.

Aerators

One of the main characteristics of aerators is the specific efficiency of oxygen dissolution, measured as a percentage per meter of aerator immersion depth. For modern new aerators, this value is 6% and even 9%, for old aerators it can be 2% or lower. The design of aerators and the materials used determine their service life without loss of efficiency, which for modern systems ranges from 6 to 10 years or more. The choice of design, number and location of aerators is carried out according to such parameters as BOD and COD of effluents at the entrance to the aeration system, by the volume of incoming effluents per unit time and by the design of aeration tanks. If we are dealing with a WWTP reconstruction with very old aerators in poor condition, then, in some cases, only the replacement of aerators and the installation of blowers corresponding to the new aerators will reduce energy consumption by 60-70%!

Blowers

As mentioned above, blowers are the main element that saves energy consumption. All other elements reduce the need for air supply or reduce the resistance to air flow. But if you leave the old uncontrolled blower with low efficiency at the same time, there will be no savings. If the aeration station uses several uncontrolled blowers, then, theoretically, by optimizing other elements of the system and achieving a decrease in the need for air supply, it is possible to decommission and transfer to the reserve several blowers from among the previously used ones and, thus, achieve a reduction in energy consumption. You can also try to compensate for daily fluctuations in the aeration system's oxygen demand by simply turning the standby blower on or off.

However, it is much more efficient to use a controlled blower, more precisely, a block of several controlled compressors. This ensures that the air supply is exactly according to the demand, which varies significantly during the day, and also varies depending on the season and other factors. The usual constant supply of air by uncontrolled blowers is always excessive and leads to excessive consumption of electricity, and in some cases to a violation of technological process nitrification-denitrification due to excess oxygen in the aerotanks. At the same time, the lack of air supply leads to the excess of pollutants in the effluent at the WWTP outlet of the maximum permissible concentrations (MPC), which is unacceptable.

Precise control of the air supply with constant monitoring of the level of dissolved oxygen in the aerotanks (and in some cases, with constant automatic monitoring of the concentration of ammonium and other pollutants in the effluent at the outlet of the aerotanks) provides an optimal level of energy consumption while ensuring that the treated effluents comply with existing regulations.

The need for several blowers in the block (for example, two large and two small ones) is due to the fact that the control range of the air compressor is very limited. It is in the range, at best, from 35% to 100% of power, more often from 45% to 100%. Therefore, one controlled blower is not always able to provide optimal air supply, taking into account daily and seasonal changes in demand. Today, the most famous are three types of blowers: rotary, screw and turbo.

Choice desired type Blowers are mainly produced according to the following parameters:

- the maximum and nominal air supply demand - depends on the parameters of the installed aerators, which, in turn, are selected based on their efficiency and on the need of the entire aeration system in dissolved oxygen, as described above;

- the required maximum overpressure at the outlet of the blower - is determined by the maximum possible depth of the aeration pool effluents, more precisely by the depth of the location of the aerators, as well as pressure losses during the passage of air through the pipeline and through all elements of the system, such as valves and so on.

As a rule, each controlled blower has its own control unit, it is also important to have a common control unit for all blowers, providing optimal mode their operation. In most cases, control is carried out by the pressure at the outlet of the blower unit.

Controlled air valves

If the system has one blower (or blower unit) supplying air to only one aeration basin, then it is possible to work without air valves. But, as a rule, at aeration stations, a block of blowers supplies air for several aeration tanks. In this case, air valves are needed at the inlet to each aeration tank to control the distribution of the air flow. Additionally, valves can be used on pipes that distribute air supply to different zones of one aerotank. Previously, manually operated butterfly valves were used for these purposes. However, remote control valves must be used to effectively control the aeration system.

Important characteristics of pilot operated valves include:

1. The linearity of the control characteristic, i.e. the degree to which a change in the position of the valve actuator (actuator) corresponds to a change in air flow through the valve over the entire control range.
2. Error and repeatability of working out by the valve actuator of a given set point for the air flow. It is determined by the quality of the valve (linearity of the control characteristic), the actuator and the actuator control system.
3. Pressure drop across the valve in the operating opening range.

The pressure drop across butterfly valves at partial opening can be very significant and reach 160-190 mbar, which leads to large additional energy costs.

If the system uses even the highest quality, but universal valves (designed for both water and air), then the pressure drop across such valves in the operating range of opening (40-70%) is usually 60-90 mbar. Simply replacing such a valve with a specialized VACOMASS elliptic air valve will result in additional energy savings of at least 10%! This is due to the fact that the pressure drop on the VACOMASS elliptic does not exceed 10-12 mbar over the entire operating range. An even greater effect can be achieved when using VACOMASS jet valves for which the pressure drop in the operating range does not exceed 5-6 mbar.

Piloted Specialty Air Valves

VACOMASSfirmsBinder GmbH, Germany.

Often, at the installation site of a controlled valve, a narrowing of the pipeline is made to use the valve of the optimal size. Since the contraction and expansion is carried out in the form of a Venturi tube, this does not lead to any significant additional pressure drop in the area with the valve. At the same time, the smaller diameter valve operates in the optimal opening range, which ensures linear control and minimizes the pressure drop across the valve itself.

Dissolved oxygen sensors and valve control system

BA1 - aeration basin 1; BA2 - aeration basin 2;

PLC - program logic controller;

BV - block of blowers;

F - air flow meter; Р – pressure sensor;

O2 - Dissolved Oxygen Sensor

M - drive (actuator) of the air valve

CPS - gate valve (valve) control system

SUV - blower control system

The figure shows the most common air supply process control scheme for several aeration basins. The quality of wastewater treatment in aeration tanks is determined by the presence the right amount dissolved oxygen. Therefore, the concentration of dissolved oxygen [mg/liter] is usually taken as the main controlled value. One or more dissolved oxygen sensors are installed in each aerotank. The control system sets the setpoint (set average value) of the oxygen concentration, so that the minimum actual oxygen concentration is guaranteed to provide a low concentration harmful substances(for example, ammonium) in wastewater at the outlet of the aeration system - within the MPC. If the incoming volume of wastewater to a particular aerotank decreases (or its BOD and COD decrease), then the demand for oxygen also decreases. Accordingly, the amount of dissolved oxygen in the aerotank becomes higher than the set value and, upon a signal from the oxygen sensor, the valve control system (CLS) reduces the opening of the corresponding air valve, which leads to a decrease in air supply to the aerotank. At the same time, this leads to an increase in pressure P at the outlet of the blower unit. The signal from the pressure sensor is sent to the blower control system (SUV), which reduces the air supply. As a result, the energy consumption of blowers is reduced.

It should be noted that a well-thought-out optimal setting of a given minimum concentration of dissolved oxygen in the CPS is very important for solving the problem of energy saving.

No less important is the correct and justified setting of the set pressure P at the outlet of the blower unit.

Air flow meters

The main task of air flow meters in the aeration system in terms of energy saving is the stabilization of the air supply process, which makes it possible to lower the dissolved oxygen concentration setpoint for the control system.

The air supply system from the blower unit to several aerotanks is quite complex in terms of control. In it, as in any pneumatic system, there is mutual influence and delay in the development of control actions and signals from feedback sensors. Therefore, the actual concentration of dissolved oxygen constantly fluctuates around the setpoint (setpoint). Availability of air flow meters and common system control of all valves can significantly reduce the response time of the system and reduce oscillations. Which, in turn, allows you to lower the setting, without fear of exceeding the MPC of ammonium and other harmful substances in the effluent at the WWTP outlet. From the experience of Binder GmbH, the introduction of data from flowmeters into the management system allows you to get additional energy savings of about 10%.

In addition, if the WWTP is undergoing a phased aeration system refurbishment process in which aerators, valves, a valve control system and air flow meters are installed first while maintaining the old blower, and then moving on to the selection of new controllable blowers, then data on actual air flow will help to produce optimal choice blowers, which leads to significant savings in their purchase and operation.

A distinctive feature of the Binder GmbH VACOMASS flowmeters is their ability to work in short straight sections "before" and "after" due to special technological solutions, as well as to be installed directly in the VACOMASS valve block.

ammonium sensor

The ammonium concentration sensor can be installed in the channel at the outlet of wastewater from the aerotank system to control the quality of treatment. In addition, incorporating the readings from the ammonium sensor into the control system further stabilizes the system and provides additional energy savings by further lowering the dissolved oxygen concentration setpoint.

An example of organizing a control system for air supply to aerotanks with feedback based on a dissolved oxygen sensor (DO) and ammonium (NH4).

Air Blowers for Aeration in Wastewater Treatment

keywords: biological treatment, air blowers, aeration

Biological treatment today is one of the most environment-friendly methods of treatment of industrial and municipal wastewater. Saturation of the treated water with oxygen is a mandatory condition for an efficient aerobic biological treatment process. This is achieved with air blowers designed for compression and delivery of air, and for creation of vacuum.

Description:

Blowers for aeration during cleaning Wastewater

Biological treatment is currently one of the most environmentally friendly methods of water treatment for both industrial and domestic wastewater. For the efficient flow of the process of aerobic biological treatment a prerequisite is the saturation of treated water with oxygen. For this, blowers are used to compress and force air, as well as to create a vacuum.

When choosing equipment for wastewater treatment plants, blowers are given Special attention. The air flow required for wastewater treatment depends on the oxygen demand of the process, the required pollutant removal efficiency, and the treatment technology used. Required amount of the supplied air during cleaning in aeration tanks depends on the composition and temperature of the wastewater, the geometric characteristics of the aeration tanks, and the type of aerators used.

The design working pressure that the blowers must create should be taken based on the depth of the aerators in the aerotanks and the pressure loss in the air supply network and the aerators themselves.

The range of required blower performance, depending on the given conditions, can vary significantly and range from a few cubic meters of air to tens of thousands. At the same time, regardless of size, blowers used for wastewater aeration must meet the following requirements.

1. Aeration is one of the most energy-intensive processes. Up to 70% of the energy in wastewater treatment plants is consumed by aeration systems. Accordingly, one of the most important requirements is the high energy efficiency of the blowers used. According to requirements normative documents it is necessary to consider the possibility of utilizing the heat of compressed air for the needs of a wastewater treatment plant. It is recommended to use blower equipment that allows you to control the flow rate of the supplied air. This is due to the daily and seasonal unevenness of the inflow of wastewater, as well as changes in both the temperature of wastewater and the temperature of the air entering the blowers. When using technologies for the biological removal of nitrogen and phosphorus, it is recommended to provide flexible or stepwise control of the air supply system to aerotanks using automation tools.

2. Blowers should have a minimal environmental impact environment. The purity class of compressed air is regulated in accordance with GOST R ISO 8573-1-2016 “Compressed air. Part 1. Pollution and cleanliness classes”, which is identical to the international standard ISO 8573–1:2010* “Compressed air. Part 1: Contaminants and cleanliness classes (ISO 8573–1:2010). Oil-free blowers are currently recommended for use. The absence of oil has a beneficial effect on the maintenance of the vital activity of bacteria and microorganisms in the treatment of sewage sludge, the air of which does not contain oil particles. The air content is especially unacceptable if the water after cleaning must be reused.

3. The blower should work as silently as possible, since the increased noise level negatively affects the personnel involved in the operation of the equipment of the treatment plant.

4. The blower must be designed for the operating conditions, that is, it must be resistant to corrosion, temperature extremes and atmospheric precipitation.

5. Blowers should be easy to operate.

Fig. 8. Two-in-one blower module design

Blower - the term is more slang than technical. It is more correct to call these machines superchargers. However, given that this article is intended for a wide range of readers, we will use this term as a more common one. The blower, like any compressor machine, is characterized by two main parameters: performance and generated overpressure.

In aeration processes, as a rule, aeration tanks with a depth of 1 to 7 m are used, which determines the range of excess pressures created by blowers: from 10 to 80 kPa. As for the performance of the blower, it depends on the volume of water processed by the installation: the larger the volume, the more air is needed. For example, the possibilities of treatment facilities of a small holiday village and big city may differ by several orders of magnitude.

Accordingly, the range of required blower capacities ranges from two to three cubic meters of air per hour to several tens of thousands. Of course, such a wide range of parameters corresponds to a wide range of blower sizes, both in terms of power and dimensions. However, there General requirements, mandatory for all blowers aerating water. Firstly, the blower must be “dry”, i.e. the air supplied must be free of lubricant and wear products.

Secondly, the blower must be reliable, easy to operate and, if possible, not energy intensive, given its almost continuous round-the-clock operation. And, thirdly, the blower must be low-noise, because. often works in close proximity to human habitation. The last requirement is especially relevant now, because. the construction of treatment facilities has acquired a trend of differentiation. In other words, the construction of numerous holiday villages, individual cottages, roadside cafes, etc. also implies the construction of small treatment facilities in close proximity to housing.

It is economically justified, because communications, construction and operation costs are sharply reduced. This trend in recent times determined the demand for small-capacity blowers. Despite the great variety existing types compressor machines, it is difficult to choose a machine that meets all of the above requirements. The requirement for "dryness" of the supplied air, reliability and noiselessness sharply narrows this choice. In addition, the price of such compressors, usually imported, is high.

The range of compressors of this type offered by the domestic industry is extremely limited. For example, for small wastewater treatment plants, blowers with a discharge pressure of 20 to 80 kPa and a capacity of 5 to 1000 m3/h are required. The requirement for "dryness" of the supplied air in the specified range of parameters is mainly met by two types of blowers - volumetric action (membrane, spiral, rotary blowers) and dynamic action (turbo blowers).

Membrane blowers designed for very low productivity (5-10 m3 / h). They are mainly supplied to the Russian market by foreign companies, in particular Japanese ones. Machines consume little electricity, compact, low noise. The price of such blowers is from 500 to 1300 USD. The resource of these machines is determined by the quality of the main part - the membrane. According to the author, the operating time for the resource of this technique is 2-3 years. Attention to these machines has increased greatly, because. they are used in individual cottage construction of treatment facilities.

Scroll compressors can still be attributed to the "exotic" in the market of "dry" compressors. This is a relatively new technique, intensively mastered both here and abroad. The design of the machine implies the use of high technology in manufacturing, so the compressors are still very expensive. For example, the Swedish company Atlas Copco offers scroll compressors with a capacity of 10 to 24 m3/h at a price of up to 6000 USD. Overpressure level - up to 10 bar (100 m w.c.).

In practice, these machines, like reciprocating compressors without lubrication until they find applications in aeration systems.

Rotary blowers produces several firms near and far abroad. The range of their capacities is from 30 to 3000 m3/h. In practice, they are sometimes called gear, or type RUTs. Blowers of the AF series of the Melitopol Compressor Plant (Ukraine) were a well-known domestic brand. With the use of Western technologies, such blowers are now produced by Venibe (Lithuania). Several European companies supply such blowers to our market.

A design feature of rotary blowers is the presence of two synchronously rotating rotors. To synchronize the rotation, meshed and therefore lubricated gears are used. The presence of a timing gear assembly, of course, reduces the reliability of the machine, increases the risk of oil entering the compression cavity through the shaft seal.

In fairness, it should be noted that due to the high technological level of production, the machines of European companies are highly reliable, however, their price is several times higher than the same Melitopol ones. For example, a blower of the AF series of the Melitopol plant for the most “running” parameters (pressure 50 kPa and a capacity of 400 m3 / h) in our market costs 3000-4000 USD, while a similar blower from a European company costs 8000-10000 USD. e. The difference in the resource of the compared equipment is corresponding.

In terms of reliability, of course, more preferable turboblowers. The working element of the machine is a simple wheel with blades, rotating in a housing on ball bearings. With the exception of bearings, there are no friction units in the machine, which determines its reliability. The advantage of turboblowers should also be attributed to relatively low level noise.

The main source of noise in all types of blowers under consideration is gas-dynamic noise, that is, the noise emitted by air when passing through the flow part of the machine. In rotary blowers, this noise is low-frequency, since air is supplied in "portions", and in turboblowers - high-frequency, because air is supplied continuously. High-frequency noise is easier to muffle. Suffice it to say that, despite the installation of silencers, rotary blowers, as a rule, require separate rooms for themselves due to high level noise.

At the same time, turbomachines equipped with mufflers do not need such rooms, because. their noise level is close to sanitary norms. On fig. Figure 1 shows the comparative noise characteristics of two blowers - a rotary type of the AF series (curve 1) and a vortex type turboblower (curve 2). The curve corresponding to the PS-80 sanitary standards is highlighted separately. It can be seen from the figure that in most octave bands, the excess of sanitary standards for a rotary type blower is higher than for a vortex type blower.

Of course, this and subsequent comparative analyzes do not aim to criticize some machines in favor of others. The purpose of the analysis is to highlight the characteristic features of each type of machine, and the choice is left to the reader. In each case, the selection criteria may differ dramatically. Speaking of turboblowers, one should immediately point out the range of their performance.

In the area of ​​relatively small capacities (from 10 to 3000 m3/h), turbomachines of well-known traditional types (centrifugal, axial) are obtained, although compact, but very high-speed. The rotational speed, for example, household vacuum cleaner reaches 16000-20000 min-1. The collector motor of such a vacuum cleaner is not able to work around the clock, as required by the operating conditions of treatment facilities.

It is possible to use a multiplier, i.e. gears with an overdrive ratio, for example, toothed or V-belt. Then the drive is possible from the usual asynchronous motor. However, in this case, the design becomes much more complicated, which means that reliability decreases. It is possible to use non-contact high-speed electric motors.

At present, prototypes of such units have been created and are being manufactured by the domestic industry. For example, a centrifugal blower used in domestic ozone generators is equipped with a multiplier, the high-speed shaft of which, with the blower impeller fixed on it, rotates at a speed of over 50,000 min-1.

The toothed two-stage multiplier is lubricated with oil. Another blower, designed and manufactured for pneumatic transport systems, is made in the form of a high-speed impeller electric motor with blades cantilevered on the shaft. Working turnover - more than a hundred thousand. Special electric motor, special gas dynamic petal bearings, precision assembly and manufacturing. There is no need to talk about the cost of such a unit - it is quite large. There is no data yet on the operating time per resource.

In view of the foregoing, a relatively new type of turbomachines is of great interest - vortex. Due to the specificity of the air compression mechanism in the flow path of these machines, the range of their performance and pressure is similar to the range of rotary machines. At the same time, vortex machines are free from the disadvantages of rotary machines: they have a much higher reliability and are less noisy.

The rotational speed of vortex turbomachines is 3000-5000 min-1, which simplifies their drive. At MSTU im. Bauman, a whole range of domestic vortex-type turboblowers has been developed and is currently being mass-produced by the industry. The designs are original and protected by patents in Russia, the USA and a number of European countries.

According to their characteristics, the machines are not inferior to the best foreign analogues. A fairly rich experience has already been accumulated in the operation of such machines, including at treatment facilities. First of all, these are EF-100 machines. Their capacities range from 200 to 800 m3/h and pressures up to 80 kPa. On fig. 2 shows a vortex blower from the EF-100 series. The machine is mounted on the same frame with an electric motor and is connected to it by a V-belt drive.

By selecting the pulleys and the power of the electric motor on almost one machine, they get a whole network various characteristics. On fig. 3 shows the performance characteristics of EF-100 turboblowers, sixteen standard sizes. Note that the characteristics are almost inverse proportional dependence pressure from productivity, which is very convenient for automation and regulation.

It is also important that, unlike the characteristics of centrifugal type turbomachines, these characteristics do not have surge zones, i.e. in practice, the machine works steadily above the nominal pressure, while consuming only additional power. At the same time, the power consumption decreases with the increase in productivity. In centrifugal turbomachines, the opposite is true.

That is why vortex turbomachines are not afraid of starting modes. The selection of pulleys and electric motors, such as in the EF-100 series, is the easiest and most cheap way obtaining a network of performance characteristics on one vortex machine. However, this is inconvenient from the point of view of regulation as a process of automatic change of parameters. In aeration systems, the need for air can vary significantly, both during the day (day and night), and depending on the season (summer, winter).

In order to save energy, and this saving can reach up to 40%, systems of automatic control of air supply by changing the speed of the turbo blower have recently found increasing use. Thanks to the frequency conversion devices that have appeared on the market, the automatic control system has become simple and affordable.

In a vortex turboblower, a change in the rotational speed shifts the characteristic in one direction or another, almost equidistant to the original one. In other words, the field of characteristics shown in Fig. 3 can be obtained practically on one machine by changing the rotational speed using a frequency converter. Such a machine has been developed. Vortex vacuum compressor VVK-3(Fig. 4) is made in the form of a monoblock, i.e. the impeller is mounted directly on the motor shaft.

Nominal parameters of the machine: productivity - 700 m3/h, discharge pressure - 40 kPa, speed - 3000 min-1. By reducing the rotational speed with the help of a frequency converter included in the electric motor power circuit, it is possible to obtain almost any operating point in the characteristic field shown in fig. 3. VVK-3 is the largest machine from the VVK series of vortex blowers.

All machines in this series have common feature are monoblocks. The first machine from this series - VVK-1 (Fig. 5) was developed at the Moscow State Technical University. N.E. Bauman and has been mass-produced by NPO Energia since 1991. The machine was intended for flour pneumatic transport systems in bakeries. Its working parameters:

• productivity — 120 m3/h;
• pressure - 28-30 kPa;
• electric motor power - 5.5 kW;
• weight - 80 kg;
• dimensions - 500.500.500 mm.

In 1999, these machines began to be used in aeration systems. At present, it was created and is mass-produced by the domestic enterprise ENGA LLC a new version- VVK-2 (Fig. 6). Unlike its predecessor (VVK-1), many design changes have been made to VVK-2, which increase reliability during round-the-clock operation. VVK-2 is a universal machine, because allows, with the help of a simple transformation, to obtain two versions and, accordingly, two different characteristics with the following operating points (Table 1).

Taking into account the tendency to expand the construction of small treatment facilities, which was mentioned at the beginning of the article, at the Moscow State Technical University. N.E. Bauman, at present, prototypes of vortex-type microblowers with a capacity of 5 and 20 m3 / h with an electric motor power of 0.5 and 1.5 kW, respectively, have been developed and created.

Speaking about vortex-type turboblowers, it would be unfair to keep silent about their main disadvantage - a relatively low efficiency. Its value usually does not exceed 35-40%. In fact, the energy consumption of vortex turboblowers is 1.5-2 times higher than that of rotary ones. Therefore, when choosing the type of machine, especially in the case of its round-the-clock operation, this fact must also be taken into account.

However, when we are talking about micromachines of small power, power consumption is not the most important parameter. Much more important is reliability, ease of maintenance, low noise level, given that the treatment plant country cottage should operate with little to no maintenance and close to housing. For more powerful machines, such as VVK-3, savings are possible with the help of regulation, as discussed above.

A few words about foreign analogues. One of the main manufacturers of vortex-type blowers in Europe is Siemens. The company produces a whole range of machines of the ELMO-G series (Fig. 7). Domestic vortex blowers are inferior to them only in design. In terms of technical parameters, they are not inferior in anything. As for prices, of course, the difference is great.

For example, a domestic blower VVK-2 costs about 1900 USD, a Siemens 92H unit similar in parameters costs about 4800 USD. If we talk about the range of capacities from three to several tens of thousands of cubic meters per hour, then there is no competition turboblowers traditional types, in particular, centrifugal.

Specialists have long known centrifugal blowers of the TV series, produced by the Chirchi plant (Uzbekistan). Powerful stationary units with good efficiency and high reliability. At present, their production has been mastered by a Ukrainian enterprise - Lugansk machine building plant(blowers series VTs).

Like any stationary unit with a large mass (the weight of the blowers reaches several tons), the VC blower needs good foundation. However, operating experience shows that it is not always possible to provide such a foundation. The soils on which treatment facilities, sometimes quite unstable depending on the season.

At MSTU im. N.E. Bauman, an attempt was made to create an alternative to the TV and VC series blowers. The developers took the path of creating a whole range of machines using unification methods such as sectioning and compounding, when derived units are obtained as a set of identical sections (modules).

Connecting these modules in series or in parallel determines either the total pressure or the total capacity. This technique made it possible to obtain a wide range of units with various technical parameters with a minimum of technological costs. Each section (module) can be made in two versions: either it is a stage of a centrifugal machine mounted on the same frame with an electric motor and kinematically connected to it by a belt drive, or these are two stages of a centrifugal machine, the impellers of which are respectively fixed at two ends of the motor shaft ( two-in-one scheme).

The design of the module according to the "two in one" scheme is shown in Fig. 8. Impellers and machine bodies are welded, made of sheet steel according to original technology. Axial type diffusers reduce module dimensions and have good anti-surge characteristics. By arranging the modules, you can get a wide range of machines.

In table. 2 and 3 show the main parameters of the modules and their possible combinations. These options are only an example and do not limit the number of possible combinations of modules. In addition to unification, the modular design has a number of advantages. Firstly, the small mass of the module (350-600 kg) does not require powerful foundations.

Secondly, for the same reason, the modules can be placed arbitrarily in the available areas, connecting them only with a pipeline, which gives more options for the layout of the unit. Thirdly, the module uses ordinary grease-lubricated ball bearings as shaft supports, which simplifies operation (there are no oil stations used in sliding bearings used, for example, in some modifications of TV blowers).

Fourthly, with the same energy consumption as TV units, the modular unit does not create such powerful starting loads on the power grid, because step modules can be connected in series and not have the usual margin for installed power for TV units. Let's take an example to illustrate. In the blower VTS 1-50/1.6 with the following parameters: V = 3000 m3/h; .p = 60 kPa, an electric motor with a rated power of 160 kW was used.

At the same time, the same parameters can be obtained by three series-connected modules I (Table 2) with a total power of electric motors: 30 . 3 = 90 kW. And finally, fifth, is the price. It is also in favor of the modular option. For example, the same blower VTS 1-50/1.6 costs about 17,000 USD. , while the cost of three modules I is about 11,000 c.u.

Currently at MSTU. N.E. Bauman development continues new technology. Its customers are a number of domestic companies, in particular, those involved in the installation of compact treatment facilities. The rapidly developing branch of environmental protection and human life support also stimulates new technical developments in the compressor industry.

blower or compressor low pressure are widely used in chemical, metallurgy, food and mining industries, as well as in wastewater aeration, manufacturing building materials and on the railroad.
Spetsstroymashina produces blowers of the BP series (rotary blowers), based on superchargers from the world's best manufacturers, such as Tuthill
Vacuum & Blower Systems (USA); Dresser Roots (USA, England), Aerzener Maschinenfabrik GmbH (Germany). All blowers used are ISO 9001 certified. Blowers of the BP series manufactured by Spetsstroymashina have a high efficiency, are reliable and trouble-free in operation over a long service life.

When working with the Customer, the engineers of our company carefully and scrupulously study and analyze the received technical information and offer equipment high quality at the best price.

The use of high-quality imported blowers with low noise characteristics make it possible to use blowers of the BP series directly in production facilities. For additional protection against the impact of noise radiation, Spetsstroymashina manufactures and supplies, complete with blowers of the BP series, noise-protective casings for two modifying ShK SSM and ShK Stribog SSM with an integrated blower control cabinet SHUV SSM.

The noise casing SHK SSM is designed in such a way that the opening of the minimum number of panels allows for the best service for the components and mechanisms of the blower.

The design of BP blowers allows for easy and unhindered access to the main components that are subject to periodic replacement or maintenance: belts, blower filler plugs, electric motor junction box, removable air filter cover, etc.

BP series blowers are equipped with vibration dampers. There is a possibility of simple and quick mounting of vibration dampers on concrete foundation production premises.

To automate the operation of equipment, Spetsstroymashina produces various cabinets blower control SHUV ZT SSM (star-delta), SHUV PlP SSM (blower control cabinet with soft start), SHUV ChP SSM (blower control cabinet with frequency drive) and others. Mitsubishi etc.

Through the efforts of the designers of the Spetsstroymashina company, it was possible to design blowers of the BP series, harmoniously combining quality, compactness and the ability to install drive motors from different manufacturers on one base.

Weight and dimensions characteristics of blowers of the BP series are commensurate with foreign analogues. Installing BP series blowers saves a lot of floor space and increases convenience. Maintenance equipment.

In the event that the Customer does not have premises for installing equipment, Spetsstroymashina manufactures and installs blowers in a block of containers of the Sever type with varying degrees automation and also carries out service and commissioning works.

Blowers manufactured by Spetsstroymashina undergo strict quality control and mandatory certification, which allows our products to compete with many global manufacturers of low pressure compressors, such as GE Roots, Vienybe, LUTOS, Robuschi, Kaeser Compressors, Hibon, Atlas Copco, Aerzener.

Waste water aeration - saturation of the liquid with oxygen, giving life to bacteria that process toxins, organic matter, forming silt. Bubble streams are created by diffusers installed at the bottom of the treatment pond.

Large volumes of compressed air are required for continuous operation of the equipment, which can be provided by aeration blowers.

equipment requirements

Compressors for wastewater treatment plants are selected based on the following conditions:

1. The first thing you should pay attention to when choosing a compressor is the depth of the reservoir. Every 10 m of liquid column creates a pressure of 1 bar. Accordingly, a blower for treatment facilities must create a working pressure sufficient to pump air to the bottom level. As a rule, the depth of treatment facilities does not exceed 7 meters (0.7 bar - 70 kPa), thus, most models of centrifugal and VRMT blowers manufactured by Thermomechanika LLC are suitable for aeration.
2. Performance, which is calculated based on the size of the reservoir, the number and characteristics of diffusers. The volume of required air can be from 100 to 50 thousand cubic meters per hour.
3. "purity". The air must not contain impurities of lubricating coolants, which will adversely affect the vital activity of bacteria.
4. Simplicity and reliability. The low pressure compressor will have to work non-stop. For water aeration, machines with direct drive from the motor shaft, without gearboxes and V-belts, are suitable. Centrifugal blowers from the Tremomechanika plant have a resource of more than 100,000 hours of continuous operation.
5. Low noise. Increasingly, small sewage treatment plants serving the villages of private households, commercial enterprises are becoming more widespread. Proximity to housing, excludes the use of equipment exceeding sanitary norms by noise level. Acoustic indicators of vortex and centrifugal superchargers of Thermomechanics lie in the range of 50-75dB, which fully complies with the requirements of SanPiN.
6. Profitability. Energy consumption is directly dependent on the efficiency and power of the blower motor. Rotary blowers for aeration have a higher coefficient useful action, however, "gluttonous" vortex, have an advantage in terms of noise, reliability and purity of the injected air

In order not to overpay for electricity, you need an accurate calculation of a sufficient amount of air per unit of time, knowing which, a blower of a certain capacity is selected.

The use of automatic control systems also reduces the operating time of the engine, and, accordingly, the electricity bill.

How to choose

To buy the optimal type and model of the blower, to minimize the cost of wastewater aeration, call the sales department of the Thermomechanics plant, or request a call back at a convenient time.

The service engineer will perform preliminary calculations of air consumption, suggest the equipment most suitable for a particular situation.

Prices for products are announced at the request of the client, after agreeing on the model of the blower, or the terms of reference for the design of the installation.