Basin water circulation system reconstruction project.

Contents

CONTENTS

Page

Introduction

1. Results of the survey of the existing water treatment system

swimming pool MU SK "Ural"

2. Description of applied technology and hardware

during reconstruction of water treatment system

3. Description of newly introduced equipment and process flow diagram of the reconstructed water treatment system

4. Basic Layout Solutions

5. Main quantitative indicators of the reconstructed

water treatment system of the swimming pool MU SK "Ural"

6. Characteristics of drains

Introduction

The purpose of the ongoing reconstruction of the existing water treatment system of the swimming pool MU SK "Ural" (hereinafter referred to as the System) is to improve the quality (organoleptic) indicators of the pool water, reliably decontaminate the water without deteriorating its organoleptic properties, increase the rate of initial filling of the pool and removal of insoluble impurities introduced by bathers, as well as reduce the operating costs and cost of servicing the System.

As part of the ongoing reconstruction, the pipeline elements and isolation valves of the old System involved in the System operation after reconstruction are subject to revision and replacement.

Results of the survey of the existing water treatment system of the swimming pool near sk "Ural"

Composition of the existing System.

The existing Water Treatment System is built according to the classic scheme based on sand filters, and includes:

- two fast pressure sand filters with a diameter of 3 m with a filtering surface of about 7 m2 each;

- 45 m3 settling tank for clarification of tap water during its treatment with coagulant and primary settling;

- two circulation pumps K150125250 from gray cast iron ChC20 with nominal capacity of 200 m3/h at head of 20 ppm;

- two prefilters (hair heads) for protection of flow part of circulation pumps against ingress of large foreign objects;

- heat exchanger of "pipe in pipe" type for heating of water circulating in the System;

- auxiliary equipment - washing (for washing sand filters) and drainage (for discharging waste water to sewage) centrifugal pumps, drain pit, piping elements with shutoff valves.

Operation of the existing System.

When the pool is initially filled, the initial tap water (hot and cold) is supplied to the mixer, and from there to the settling tank. The necessary amount of an aqueous solution of coagulant is also supplied there - eighteen-acid aluminum sulfate (alumina). The process of coagulation and primary settling of the formed flakes lasts 3-5 hours, after which the decanate (settled water) is supplied by an auxiliary centrifugal pump (which is also used to wash sand filters) to the inlet of sand filters, and after filtration it is sent to the basin, after which the coagulation-filtration process is repeated the necessary number of times to completely fill the basin. The sludge from the sump tank at the end of each clarifying cycle is drained into the sewer pit, from where it is removed to the sewer by a drain pump equipped with a level sensor.

After filling the pool, the System is switched to constant circulation mode through sand filters and heat exchanger to bring the water quality in the pool to the required condition, maintain the required temperature and decontaminate.

Water is disinfected with the help of calcium hypochlorite aqueous solution, which is prepared in solution tank and supplied by gravity to circulation system to circulation pump suction.

The operation of the existing System is described in more detail in the Operating Manual of MU "Ural" "Operating Instructions...."

Description of applied technology and hardware design during water treatment system reconstruction

Despite the diversity of water treatment technologies currently in practice, two main stages can be identified in either of them:

converting the undesirable impurities contained in the source water into a form convenient for their subsequent separation from the purified water;

removal of converted impurities from purified water by any method.

Depending on the particular composition of the source water, the first step may include treating the water with oxidizing agents. (aeration, chlorination, ozonation, etc.) to convert part of the impurities to be removed into insoluble and volatile forms with softeners (liming) to reduce (if necessary) total stiffness, coagulants to coarse insoluble particles; (in some cases) sorption of some soluble impurities on the surface of flakes and auxiliary substances formed during coagulation.

Treatment of the source water with a coagulant in order to clarify it (reduce the value of chromaticity) and increase the particles of insoluble impurities (during the formation of aluminum hydroxide flakes), which is necessary to increase the efficiency of sand filters, has the following disadvantages:

1) a significant increase in the initial water content of insoluble impurities due to the hydrolysis of the coagulant and the formation of insoluble aluminum hydroxide, which increases the load on the filtering equipment, reduces the duration of the filter cycle and increases the water consumption for washing the filters and removing sludge from the settling tank;

2) changing the pH of treated water to decrease its values ​ ​ (the medium is acidified), which requires the use of auxiliary substances to correct the pH (alkalizers), increases the volume of control of basin water and, in case of errors in maintaining the pH, can increase the corrosive activity of water, as well as its irritating effect on the skin of bathers;

3) increase of total operating costs, as well as cost of maintenance of the System as a whole.

In the case (as will be described below) of using an alluvial cartridge filter to filter the water of the pool, which retains particles with a high efficiency up to 1 μm (for example, the cross-section of most bacteria is 3-4 μm), the need for a coagulant to coarse the insoluble impurities particles is avoided, and the discoloration of the water in this case is conveniently carried out with an oxidizing agent.

An aqueous solution of chlorine dioxide will be used as an oxidizing agent, which at the same time will serve as a powerful and highly effective disinfectant in the reconstructed System.

Chlorine dioxide (ClO2) is an unstable gas that is produced on-site in compact fully automated plants in the form of an aqueous solution of aqueous solutions of hydrochloric acid and sodium chlorite (NaClO2).

In terms of its disinfectant and oxidizing effects, chlorine dioxide at a pH of water above 7 is several times more effective than active chlorine and has practically no adverse effects associated with treatment with active chlorine due to a special mechanism of chemical action on contaminants and microorganisms.

The use of chlorine dioxide has the following advantages over chlorine:

trihalomethanes (THM) and chlorophenols are not formed;

non-detectable organic halides (NOG-chloroform, etc.) are not formed;

there is no reaction with ammonia and its compounds;

the disinfectant effect does not depend, as in the case of chlorine treatment, on the pH of the water;

there are no negative changes in the smell, taste and color of water (chlorine and chlorophenol odors and flavors), there is no irritation of the mucous membranes and skin of swimmers when using chlorine-containing reagents;

organic iron and manganese compounds are actively oxidized;

the redox potential is independent of pH and the presence of ammonia and other nitrogen compounds in water;

bactericidal effect is preserved in water for up to 7 days.

water pH does not change..

The second stage is the separation from the purified water of flakes formed as a result of coagulation, which sorbed part of the dissolved in the source water, as well as insoluble impurities. Traditionally, the suspension separation process is carried out on several types of equipment connected in series, for example, a settling tank (contact clarifier) - a sand filter, etc.

It should be noted that each of the above-mentioned apparatus must operate within a sufficiently narrow range of slurry content in the source water to provide a suitable filter cycle duration and slurry separation efficiency. Each of these devices also has a well-defined boundary of realistically achievable qualitative indicators of water purification, the position of which is especially important for the device closing the technological chain. As a rule, in the traditional water purification scheme, such an apparatus is a sand filter.

Operation of sand filter (and any other type of equipment based on water flow through the bed of granular material) It is characterized by the extreme instability of the entrainment value of the solid phase during the filter cycle, especially its finely dispersed part, as well as the dependence of the entrainment value on the filtration rate and washing quality, which leads to significant fluctuations in turbidity, chromaticity, iron, aluminum, manganese and other undesirable impurities at the filter outlet. For example, it is known that the efficiency of retention of insoluble impurities by sand filters at a filtration rate of up to 8 m/h does not exceed 80% during the initial treatment of water with a coagulant (in our case, during the initial filling of the basin and during daily renewal of water), and 3040% without treatment with a coagulant (in our case, filtration in circulation mode).

Attempts by developers to reduce the residual content of insoluble impurities in the basin water using sand filters are mainly aimed at increasing circulation volumes (productivity of filters and circulation pumps), which, on the one hand, leads to a slight decrease in the residual content of suspensions in the basin water, on the other hand, causes an increase in the cost of equipment and an increase in operating costs.

Considering that the increase in the filtration rate of water through the bed of granular material has a limit due to the nature of the interaction of particles of impurities with grains of sand (the efficiency of retention of impurities decreases with an increase in the filtration rate and, starting from some speed value, filtration turns into washing), the same limit has the final quality of water in the basin in terms of the content of suspensions when using sand filters.

Another area of significant improvement in the quality of the water to be treated and maintenance of the stability of this quality is the use of an appropriate capacity wash cartridge filter instead of sand filters. Its use will make it possible to remove from the purified water suspensions with particle sizes up to 1 μm with an efficiency of 9598%, which will make it possible to obtain water quality in the basin (in terms of the residual content of suspended particles), which is unattainable if traditional equipment is used. The great advantage of washing filters is the insensitivity in very wide limits to the change in flow rate, the absence of the need for wash water and washing pumps (unlike sand filters), small dimensions and mass, the implementation of all elements of the filter made of corrosion-resistant steel and a decrease in maintenance capacity.

Taking into account the above, as well as taking into account the described modern trends in the construction and operation of water treatment equipment for water treatment of swimming pools, the following hardware and technological solutions should be implemented during the System reconstruction:

1) chlorine dioxide can be used to bleach and disinfect water to give it residual bactericidal properties; Completely exclude chlorination of water;

2) use the NPF100 cartridge filter manufactured by Uralhydrosfer CJSC instead of obsolete sand filters with corresponding changes in binding; connect an alluvial filter with auxiliary equipment in such a way as to preserve as much as possible the procedure for water exchange and drainage accepted in the MU basin of SK Ural;

3) use modern means of control and regulation of disinfection and filtration processes.

Description of newly introduced equipment and process flow diagram of the reconstructed water treatment system

3.1. Main provisions.

The complete hardware and technology diagram of the System is shown on sheet No. 4.

The basic hardware and technology diagram of the filtration unit itself with the points of connection to the existing equipment and communications, as well as the points of connection of the Plant for the production and dosing of chlorine dioxide is shown on sheets No. 3 and No. 6.

The basic hardware and technology diagram of the Plant itself for the production and dosing of chlorine dioxide with a detailed description, placement and connection of its components is given in the project developed by NPP TEKO CJSC, Yekaterinburg.

The NPF100 filter with auxiliary equipment and newly introduced circulation pumps and piping elements is connected to the existing circuit of the reconstructed System according to the diagram sheet No. 6. The purpose of the connection elements is given in Tables 1 and 2.

Connection of new equipment to the existing scheme (MU SK "Ural").

The purpose and characteristics of the newly introduced non-plasticized polyvinyl chloride gate valves are shown in Table 3.

3.2. Characteristics of newly introduced main equipment

3.2.1. Rinse filter NPF100.

Filter NPF100, drawing UGS.021.000SB, is a vertical cylindrical device with elliptical bottom and cover. Between the flanges of the cover and the filter body, a partition with holes is clamped through the gaskets, into which 167 filtering elements (cartridges) are inserted, which are polyhedral rods with wire wound on them, which during winding is deformed to obtain pits with a width of 5090 μm between the turns, which form a drainage substrate to support the auxiliary filtering material - filterperlite (hereinafter referred to as WFM M M). Filter has inlet (D100) and outlet (D80) branch pipes with flanges.

Oil cartridge filters (NPF) are one of the most progressive types of filtering equipment. NPFs are designed for fine mechanical filtration of liquid inhomogeneous media with a suspended particle content of up to 15-20 mg/l.

The main advantages of NPFs over devices of the same purpose:

1) relatively small dimensions and weight;

2) high degree of purification from suspensions - 95-98% with particle size of retained particles up to 1 μm;

3) no need to use chemical additives (coagulants, etc.);

4) unlimited service life;

5) ease of regeneration and washing;

6) small volume of flushing water - less than 0, 05% of volume of purified liquid;

7) wide field of application: from purification of food products (beer, wine) to post-treatment of waste water (including oil products);

8) cheapness and availability of auxiliary filter material (filter perlite);

9) all insoluble impurities separated by the filter cycle in the regeneration mode are removed in a compact and convenient form for disposal.

The proper washing cartridge filter is a sealed apparatus made of stainless steel, divided into two parts by a partition in which filter cartridges are fixed.

The filter cartridge is a polyhedral perforated tubular frame on which stainless wire is tightly wound. During winding, the wire is deformed according to a special technology in such a way that slots with a width of 90 μm are formed on the surface of the cartridge.

At the beginning of the filter cycle, a special technological operation (washing) is carried out to apply a layer of auxiliary filtering material (VFM) to the filter cartridge, through which filtration is carried out in the future.

An auxiliary filtering material - filteroperlite - is a light white powder obtained from natural mineral raw materials and has a narrow fractional composition (5-120 microns). In order to carry out the washing operation, an aqueous (or on the basis of a particular medium to be filtered) suspension of a certain concentration of filter perlite is prepared. Filteroperlite has a hygienic certificate and is approved for use in contact with drinking water and other food media.

At the beginning of the filter cycle, during the washing, the filter perlite is applied to the surface of the filter elements with a flat layer in the form of a kind of "stockade" with a thickness of 2-5 mm, through which filtration is carried out; Note here that filtration process qualitative indices depend only on filtration perlite rheological properties. After completion of the filter cycle, the spent filter filter with retained impurities using a special technological technique (pneumohydraulic impact) is dropped from the surface of the cartridges and removed to the sewage system along with water filling the filter.

The sequence of operations for discharging spent filter perlite with subsequent filling of the filter with water and washing of fresh VFM is called regeneration of the wash filter. In time, regeneration takes 1520 minutes.

The NPF plant generally includes a filter itself, a VFM slurry preparation tank, a centrifugal pump for washing (in the case of using several filters, one tank and one pump for the entire process chain), piping and shutoff valves.

Main technical characteristics of NPF100 filter, drawing UGS.021.000SB:

filtration surface... 25 m2;

number of filtering elements........ 167 pieces;

the amount of filter perlite required per wash... 12... 15 kg;

design pressure....................................................... 1.0 MPa;

maximum operating temperature................ ......... 1000 С.

dimensions:

internal diameter of the filter.... 1200 mm;

maximum height from zero elevation... 2785 mm;

maximum outer diameter (by flange).......... 1350 mm;

weight of the metal structure of the filter........................ 2215 kg;

filter weight in operation (under filling).................... 4570 kg;

operating (filled) volume.............................. 2,355 m3;

main structural material.... steel 12X18H10T.

3.2.2. Washing tank.

The washing tank, drawing UGS.021.600SB, is designed to prepare concentrated suspension of VFM, and is also used as an element of the circulation system during the operation of washing VFM to filter elements of the NPF100 filter. The tank is a thin-walled vertical tank with a conical bottom, has inlet and outlet branch pipes with flanges, a hydraulic mixer, a branch pipe for emptying the tank and a platform for maintenance personnel used in loading dry pearlite.

Main technical characteristics of the washing tank:

weight of steel structure of the tank.............. 193 kg;

tank weight in operation (under filling)..... 2000 kg;

- main structural material.... steel 12X18H10T.

3.2.3. Circulating centrifugal pumps (working and standby) are designed for continuous circulation of pool water through the washing filter and heat exchanger, for filtration of water treated with chlorine dioxide when it is pumped from the settling tank through the washing filter to the pool, as well as for the operation of flushing the VFM at the beginning of the filter cycle.

Main technical characteristics of circulation pumps:

pump type....................... H10080160KSU2;

nominal capacity......... 100 m3/h;

head at rated capacity...... 32 ppm;

engine electric power..... 22 kW;

power spent on pumping water at

nominal characteristics......... 12.9 kW;

total weight of the pump............. 440 kg;

material of pump flow section.... steel 12X18N9TL .

The pumps can be operated in a manual mode, in which the productivity change when the filter resistance increases is performed manually by changing the position of the gate valve control disk, as well as in an automatic mode, in which the specified productivity, measured by the ultrasonic flow meter, is maintained by changing the rotation speed of the pump motor, which carries out the frequency-controlled drive PS17 ("Save").

3.3. Description of process flow diagram.

The NPF100 filter with auxiliary equipment is connected to the existing process diagram instead of the existing sand filters and old cast iron centrifugal pumps; Note here that old filters and pumps, including flushing and drainage ones, take out sand filter flushing water from the box, are not engaged and their process lines are deafened.

The reconstructed System operates in three main modes:

initial pool filling and primary water conditioning;

circulation mode;

the mode of daily replenishment of the pool is fresher than the water processed by oxidizer and filtered with replacement of old water in the sewerage, in a bakotstoynik, or to "paddling pool" and other pools of MU SK "Ural". Other drainage schemes are also possible.

3.3.1. Initial pool filling mode.

In this mode, cold tap water is supplied to the existing mixer, and from there to the settling tank. At the same time, an aqueous solution of chlorine dioxide is supplied to the water supply line to the settling tank (after reconstruction this section of the pipe is replaced with a pipe of polyvinyl chloride) from the chlorine dioxide preparation plant in a strictly defined amount, depending on the amount of impurities of the source water that can be oxidized (give electrons under the influence of the oxidizer). Chlorine dioxide dose is set during commissioning; about 0.5 mg/l to 1.0 mg/l; the final chromaticity of the water treated with the oxidant should be within 0... 3 degrees on a normal scale. The volumetric supply of source water to the settling tank is determined based on the chlorine dioxide dose value, as well as on the maximum capacity of the chlorine dioxide plant (45 g/h), i.e., with the required oxidant dose of 1.0 mg/l, the volumetric supply of cold water to the settling tank should not exceed 45 m3/h. In the settling tank, impurities are oxidized and converted into volatile, soluble and insoluble (suspensions), which will be delayed during subsequent filtration on an alluvial filter.

After filling the tank, the extraction of treated water by circulation pumps begins and it is pumped through the washing filter to the pool (VFM is washed onto the filtering elements of the washing filter before the start of the filter cycle (the washing operation is discussed in detail below). The water supply to the settling tank and its continuous pumping out from the tank through the filter to the pool (filling the pool) occurs in a continuous mode; Note here that pool filling rate depends on required dose of chlorine dioxide and corresponding rate of cold water feed into settling tank (as described above).

After filling the pool with initially purified water, the supply of tap water to the settling tank is stopped (it can be filled with water treated with oxidizer), and the System switches to operation in continuous circulation mode through the heat exchanger (for heating to the desired temperature) and the NPF100 filter - for final retention of insoluble impurities, the formation of which could be completed already in the pool. The duration of primary water conditioning may range from 8 to 24 hours; thus, at a pool filling rate of 45 m3/h, water filling and primary conditioning will be completed through:

3.3.2. Circulation mode.

After completion of the primary water conditioning mode and analytical confirmation of water compliance with the requirements of regulatory documentation, normal operation of the basin begins; water circulation through the filter is carried out around the clock until completion of the filter cycle .

In the course of a filter cycle, additional chlorine dioxide can also be supplied to the suction of circulation pumps (for better mixing with water) if the results of water analyses showed a chlorine dioxide content of less than 0.1 mg/l (this dose of residual dioxide in water is a guarantee of reliable water disinfection).

The circulation system is additionally equipped with a controller and a measuring sensor with a flow cell for continuous detection of the content of chlorithione in water, which is a by-product when oxidizing water impurities with chlorine dioxide; its content in water is regulated. If, for any reason, the chlorite ion content in the water of the basin exceeds the established norm, an aqueous solution of sodium hyposulfite binding chlorite ion is supplied to the water (to the pump suction) by a special dosing pump.

3.3.3. Daily Water Renewal Mode.

In accordance with the requirements of the regulatory documentation, during the operation of the basin, approximately 10% water should be updated daily to dilute soluble impurities accumulating in the basin water that are not removed by filtration, i.e. 85 m3 of fresh water should be treated with an oxidizer and supplied to the basin through an oil filter during the day. This operation is similar to the initial filling of the basin, that is, cold tap water with the required dose of chlorine dioxide is supplied to the settling tank and is continuously pumped out of the tank through the filter. The amount of fresh water supplied to the pool is conveniently controlled by an ultrasonic meter meter. The excess water may, as shown above, be discharged to the sewer, to the sump tank and then removed to the sewer, to the frog and other pools, or otherwise.

3.3.4. Maintenance of temperature conditions.

As is known, the source tap water used for pool filling and daily updating shall meet the requirements of SanPiN 2.1.4.107401 "Drinking water. Hygienic requirements for water quality of centralized drinking water supply systems. Quality control. " Water from the hot water supply line according to the quality indicators established by SanPiN 2.1.4.107401 for drinking tap water is not controlled and, as a rule, does not correspond to it: it everywhere shows increased chromaticity and content of iron oxidation products, corrosion inhibitors may be present, as well as pathogenic bacteria, especially spore-forming forms, so hot water should not be used to water the pool. The thermal mode shall be maintained by means of an existing heat exchanger through which the pool water is continuously circulated; Note here that water temperature can be controlled by changing heat carrier (hot water) feed to heat exchanger.

Basic Layout Solutions

The NPF100 filter with auxiliary equipment and binding elements is located on the free space of the filtration unit under the pool bath specified by the Customer. Placement of the filter, the mutual provision of elements of the System and pipelines with again entered shutoff valves, points and a way of connection to the existing pipelines and the equipment are shown on assembly drawing UGS.021.700SB.

A lifting device based on a manual chain hoist with a lifting capacity of 1.5 tons is also mounted at the filter installation site for mounting parts of the filter body and the package of filter elements and (if necessary) for dismantling the filter elements during subsequent operation .

The existing drainage pit during construction and installation works should be increased to the volume of 2.2... 2.5 m3 in order to simultaneously accept the full volume of water from the filter housing with spent WFM during regeneration. Water from the pit is removed in a conventional manner by means of an existing drain pump, which is turned on automatically.