Active Edition from 20.05.1986

"SEWER. EXTERNAL NETWORKS AND FACILITIES. SNiP 2.04.03-85" (approved by the Decree of the USSR Gosstroy of 05/21/85 N 71) (as amended on 05/20/86)

Specific costs, non-uniformity coefficients and estimated wastewater costs

2.1. When designing sewerage systems for settlements, the calculated specific average daily (per year) disposal of domestic wastewater from residential buildings should be taken equal to the calculated specific average daily (per year) water consumption in accordance with SNiP 2.04.02-84, excluding water consumption for irrigation of territories and green spaces.

2.2. Specific wastewater disposal to determine the estimated flow rates of wastewater from individual residential and public buildings if necessary, accounting for concentrated costs should be taken in accordance with SNiP 2.04.01-85.

2.3. The estimated average daily flow rates of industrial wastewater from industrial and agricultural enterprises and the coefficients of uneven inflow should be determined on the basis of technological data. At the same time, it is necessary to provide rational use water through the use of low-water technological processes, water recycling, water reuse, etc.

2.4. Specific wastewater disposal in non-sewered areas should be taken as 25 l / day per inhabitant.

2.5. Estimated average daily wastewater consumption in locality should be determined as the amount of expenses established under paragraphs 2.1 - 2.4.

The amount of wastewater from local industry enterprises serving the population, as well as unaccounted expenses, may be taken additionally in the amount of 5% of the total average daily water discharge of the settlement.

2.6. Estimated daily wastewater flow rates should be determined as the sum of the products of the average daily (per year) wastewater flow rates, determined in clause 2.5, by the coefficients of daily unevenness, taken in accordance with SNiP 2.04.02-84.

2.7. Estimated maximum and minimum expenses wastewater should be determined as the product of the average daily (for the year) wastewater discharges, determined according to clause 2.5, by the general non-uniformity coefficients given in Table 2.

table 2

Notes: 1. The general coefficients of non-uniformity of the inflow of wastewater, given in Table 2, can be taken with the amount of industrial wastewater not exceeding 45% of the total flow. When the amount of industrial wastewater is more than 45%, the general non-uniformity coefficients should be determined taking into account the uneven discharge of domestic and industrial wastewater by hours of the day according to the data of the actual inflow of wastewater and the operation of similar facilities.

2. With an average wastewater flow rate of less than 5 l / s, the estimated costs should be determined in accordance with SNiP 2.04.01-85.

3. For intermediate values ​​of the average wastewater flow rate, the total non-uniformity coefficients should be determined by interpolation.

2.8. Estimated costs of industrial wastewater industrial enterprises should be taken:

For external collectors of an enterprise that receives wastewater from workshops - at maximum hourly costs;

For plant-wide and off-site collectors of the enterprise - according to a combined hourly schedule;

for an off-site collector of a group of enterprises - according to a combined hourly schedule, taking into account the time of wastewater flow through the collector.

2.9. When developing the schemes listed in clause 1.1, the specific average daily (per year) drainage can be taken according to Table 3.

The volume of wastewater from industrial and agricultural enterprises should be determined on the basis of consolidated standards or existing analog projects.

Table 3

Notes: 1. Specific average daily water disposal may be changed by 10 - 20% depending on climatic and other local conditions and the degree of improvement.

2. In the absence of data on industrial development beyond 1990, it is allowed to take additional expense wastewater from enterprises in the amount of 25% of the flow rate determined according to Table 3.

2.10. Gravity lines, collectors and channels, as well as pressure pipelines of domestic and industrial wastewater, should be checked for the passage of the total calculated maximum flow rate according to paragraphs 2.7 and 2.8 and additional inflow of surface and ground water during periods of rain and snowmelt, unorganized entering the sewerage network through leaks in well hatches and due to groundwater infiltration. The value of the additional inflow q_ad, l/s, should be determined on the basis of special surveys or operation data of similar facilities, and in their absence - according to the formula

Where L is the total length of pipelines to the calculated structure (pipeline alignment), km;

m_d - the value of the maximum daily precipitation, mm, determined according to SNiP 2.01.01-82.

Verification calculation of gravity pipelines and channels with a cross section of any shape for the passage of increased flow should be carried out when filling 0.95 height.

6.1.3 Calculation of coefficients for hourly, daily and general unevenness

Due to the duration of the processing of fur sheepskin, fluctuations in wastewater consumption are observed daily. The initial data on the flow of wastewater to treatment facilities are presented in Table 6.

Table 6 - Initial data on the flow of wastewater to treatment facilities

This table describes the uneven flow of wastewater to the treatment plant at different hours of the day. The discharged volume also differs in different hours and days. This is due to the peculiarity of technological processes in the production of fur sheepskin. Those. drainage is explained by the ability of the leather tissue to absorb the solution, determined by the moisture content of the raw material.

Therefore, for each day of the week, the coefficient of hourly unevenness is calculated using the formula (6):

K hour = Q max day / Q cf hour, (6)

where: K hour - the coefficient of hourly unevenness; Q max - the maximum volume of sewage inflow during the day, m 3; Q cf - average hourly inflow of wastewater, m 3.

The average hourly inflow of wastewater is determined by the formula (7):

Q cf = ∑Q i / 24, (7)

where: Q i – wastewater inflow to the treatment plant at i – hour; 24 is the number of hours in a day.

The coefficient of daily unevenness is determined by the ratio of the maximum daily flow to the average daily flow according to the formula (8):

K day \u003d Q max weeks / Q avg weeks, (8)

The overall coefficient of non-uniformity of water disposal at enterprises is calculated by the formula (9):

K total \u003d K hour × K day, (9)

Calculation example:

Day of the week-Tuesday

a) Calculation of the average daily wastewater inflow:

Qav = (2.863+0.026+2.753+2.863+0.032+2.753+2.753+2.753+2.753+ 2.753+0.031+ +0.02)/24=0.93

b) Calculation of the coefficient of hourly unevenness:

K hour \u003d 2.863 / 0.93 \u003d 3.1

c) Calculation of the coefficient of daily unevenness:

K day = 2.863/((2.863+0.026+2.753+ 2.863+0.032+2.753+2.753+2.753+2.753 +2.753+ + 0.031+0.012)/7) = 0.23

d) General coefficient of unevenness:

K total \u003d 3.1 × 0.23 \u003d 0.713

A similar calculation is carried out for each day of the week, the data obtained are entered in table 7.

Table 7 - Coefficients of non-uniformity of wastewater inflow to treatment facilities during the week

6.1.4 Calculation of specific water consumption and wastewater disposal per unit of output

One of the indicators characterizing the level of impact of the enterprise on environment is the assessment of specific water consumption and wastewater disposal per unit of output.

The actual water consumption in the dressing of fur sheepskin is determined by the following indicators:

For production needs 75-85%

For household needs 5-6%

Water formed after precipitation or storm water 2-3%

Conditionally pure water used for cooling equipment or in refrigerators, fans, compressor units 6-18%

Initial data:

The capacity of the enterprise is 10,000 pieces of sheepskin per year

Number of working days 250

The volume of waste water is:

Production 75%

Household 6%

Conditionally net 16%

Stormwater 3%

The volume of water disposal, taking into account industrial and household needs in the processing of sheepskin, is: 23.84 m 3 / day or 5960 m 3 / year, of which:

Production 17.88 m 3 /day or 4470 m 3 /year

Household 1.43 m 3 / day or 357.5 m 3 / year

Conditionally clean 3.81 m 3 / day or 952.5 m 3 / year

Stormwater 0.72 m 3 / day or 180 m 3 / year

It is known that in the process of performing technological operations, on average, water losses for production needs do not exceed 6%, then the total volume of water consumption will be:

23.84 + (23.84 × 0.06) \u003d 25.27 m 3 / day or 6317.5 m 3 / year

Let us determine the specific volume of water consumption and wastewater disposal per unit of output:

a) specific volume of water consumption per unit of output

The actual volume of water consumption will be 6317.5 m 3 / year

The capacity of the enterprise per year is 10000 pieces of sheepskin

Then, 6317.5 m 3 / year - 10000 pieces

X m 3 / year - 1 unit of output, X \u003d 0.63 m 3 / year

b) specific volume of water disposal per unit of output

The actual volume of wastewater is 5960 m 3 / day

5960 m 3 / year - 10000 sheepskins

X m 3 / year -1 unit, X \u003d 0.6 m 3 / year

Information about the work "Study of the properties of a bacterial suspension and its application in the preparatory processes for the processing of fur raw materials"

The external sewer network is designed based on the total wastewater flow. For its calculation, water discharge standards are used.

The rate of disposal of domestic wastewater is the average per day conditional volume of such water, which falls on one inhabitant of the facility to be sewered. The rate is measured in liters.

For process wastewater, this amount is calculated relative to one unit using water according to technological map process.

For residential facilities, water disposal standards are usually equated to water consumption standards. This is due to the fact that domestic wastewater, in fact, is used tap water contaminated during its use for domestic needs. Not all water supplied to the consumer water supply network can enter the domestic sewer network. This is the volume that is used for washing technical equipment and their cooling, pavement, watering green spaces, feeding fountains, etc. When it is taken into account, the water disposal rate for this share should be reduced.

Drainage standards are regulated by SNiP P-G.1-70. Their values ​​depend on the conditions of the local climate and others: the presence or absence of internal water supply, sewerage, centralized hot water supply, water heaters for baths, etc.

Water consumption varies in accordance not only with the season of the year, but also with the time of day. In the same mode, water disposal should also change. The hourly uneven flow of effluents into the sewer depends on their total volume. The greater the total flow, the less this unevenness is felt.

Coefficients of non-uniformity of water disposal

When designing a sewer system, it is necessary to proceed not only from the normative and total volumes of wastewater that can be discharged. It is also important to take into account fluctuations in the daily regime of water disposal. The system must be able to cope with wastewater disposal during peak hours. This also applies to all its parameters, for example, the power of fecal pumps. To calculate the maximum flow rates, the appropriate amendments are used - the coefficients of non-uniform drainage.

The fractional calculation of uneven drainage up to one hour is required only for objects with a high probability of it. In other cases, the possible hourly unevenness is taken into account in the previously accepted margin in the volume of pipes. In hydraulic calculations of the sections of pipelines, their filling is preliminarily partial.

The coefficient of daily non-uniformity kcyt of water disposal is the ratio of the daily maximum flow rate of wastewater Q max. day to the daily average flow rate Q average day for the year:

k days = Q max. days / Q average days

Similarly, the coefficient of hourly unevenness khour of drainage is determined:

k hour = Q max. hour / Q average hour

Here Q max.hour and Q average hour - the maximum and average hourly costs. Q average hour is calculated by consumption per day (dividing it by 24).

By multiplying these coefficients, the coefficient of general unevenness k total is calculated:

k total = k day k hour

The general coefficients depend on the value of the average flow rates and are given in the relevant tables for designers.

To calculate this coefficient for values ​​of the average flow rate that are not in the tables, interpolation is applied according to their nearest data. The formula proposed by Professor N. F. Fedorov is used:

k total = 2.69 / (q cf) 0.121.

The value of qav is the wastewater flow rate in 1 second (average second) in liters.

The formula is valid for average second flow rates up to 1250 liters. The coefficient of daily non-uniformity of water disposal for public buildings is taken as a unit.

The coefficient of hourly non-uniformity for process wastewater strongly depends on the production conditions and is very diverse.

From the calculated data in Table. 7.2 it is established that the coefficient of irregularity in the receipt of material and raw materials is 3.29 (irregularities \u003d 236 108/21 800 - \u003d Y10.83 - \u003d\u003d + 3.29). The coefficient of unevenness shows that the supply of raw materials and materials was carried out in violation of the plan and monthly deviated from the planned conditions by 3.3%.

On gas pipelines, fluctuations in the mode of operation of the main are taken into account using the coefficient of non-uniformity of gas supply

gas consumption Ku (in RUB/1000 m) with UGS capacity, mln. m1 EU IB RUB/1000 m") with UGS capacity, mln. m

Gas consumption fluctuation coefficient Storage capacity, mln m3 Storage capacity, mln m1

To assess the rhythm of supplies, the following indicators are used: coefficient of rhythm, number of arrhythmia, standard deviation, coefficient of irregularity in supplies, coefficient of variation.

The coefficient of uneven supply of materials is calculated by the formula

In addition, the determination of the required volume of capacities of transshipment points using existing methods can be made only on the basis of average or maximum transshipment volumes per month, taking into account the coefficient of unevenness.

Consequently, the main disadvantage of the non-uniformity coefficients used in the calculations is that they do not take into account the non-uniformity of oil products transshipment (in time and quantity).

Since the calculations of the required volume of the tank farm of transshipment points, obtained taking into account the coefficient of non-uniformity, do not provide a reliable and even more optimal solution, it becomes obvious that a different fundamental basis must be chosen.

The algorithm for calculating the coefficient of uneven oil supply is presented in the form of a block diagram (Fig. 14). To clarify the block diagram, we introduce the designations t - years of the retrospective period th month t-th year of the retrospective period Kr - coefficient of unequal

Block 13 - issuing for printing the calculated values ​​of the unevenness coefficients for each oil depot for the years of the retrospective period. The form of presentation of the output information is similar to the form shown in Table. 24.

When determining the reduced costs for the processing of petroleum products at the facilities of the oil storage facilities, it is necessary to take into account the movement of fixed assets, their write-off and restoration. Moreover, capital investments in the development of these facilities for reconstruction and expansion for each control year of the planning period should be accounted for separately. All capital investments for the first planning period refer to the first control year, and capital investments of the second period - to the second control year on an accrual basis. When determining the reduced costs, the minimum cost of processing corresponding to the maximum possible throughput should also be taken into account. The minimum cost should be determined on the basis of studying for each tank farm the dependence of the level of current costs on the main factors of production, i.e., demand for petroleum products in the service area (sales volume), the cost of existing fixed assets, the coefficient of uneven supply of the tank farm and the time factor. When determining the reduced costs, taking into account the expansion of existing oil depot facilities provided for by the projects, one should take into account the share of costs that depend on the volume of sales of petroleum products. It can vary over a wide range depending on the "category of tank farms, the volume of sales of petroleum products and the characteristics of transport services. In this regard, the share of dependent costs should be determined separately for each tank farm based on a study of the behavior of this indicator over a long retrospective period.

Given in table. 7.1, the data indicate that in the analyzed period the logistics plan was not fulfilled, the supply of material and raw materials was carried out unevenly. To measure the degree of non-uniformity of supplies, we use the indicator of the standard deviation (coefficient of non-uniformity) as an indicator of the average size of the fluctuation in the value or other feature of the object under study compared to its average level. The procedure for calculating this indicator will be considered using the example of the iosta-

M201. Calculation of the coefficient of non-uniformity of oil supply by oil depots

Oil depot Year Observation number Capital productivity Cost price 2, rub/t Labor productivity X, Tank capacity X4, t Coefficient of oil supply unevenness Sales volume of oil products X t

Block 2 - formation of a working array of the oil supply unevenness coefficient using the M201 module.

MODULE M201. CALCULATION OF THE COEFFICIENT OF IRREGULARITY OF OIL SUPPLY BY OIL DEPOSITS

Block /0 - calculation of the coefficient of non-uniformity of oil supply at the p-th oil depot by years of the retrospective period. Creating array B2111.

The array of the coefficient of uneven supply of oil depots for the retrospective period is the array B2111.

Block 11 - construction of predictive models for the dependence of economic indicators (cost, capital productivity and labor productivity) on the p-th oil depot on objective factors of production (freight turnover, replacement cost of fixed assets, coefficient of unevenness) and the time factor t. The predictive model is built on the basis of the dependence of economic indicators on objective factors of production for the retrospective period using the M108 module

When determining the reserves for increasing throughput in the second way, an attempt is made using the methods of multivariate classification and correlation-regression analysis to establish the influence of the main objective factors of oil supply on the economic performance of tank farms and develop economic and statistical models of indicators that could be used for the purposes of oil supply planning. At the same time, the dependence of capital productivity (x) on such factors as the volume of sales of petroleum products (xv), the coefficient of uneven oil supply (x5), and the volume of the reservoir capacity (x4) is studied. Initially, a multidimensional classification of tank farms is carried out according to objective factors of production. Then in each class is built

Structures on the network

Inspection wells on the drainage networks of all systems are arranged at the points of connection (nodal); in places of change in directions, slopes and diameters of pipelines (rotary); on straight sections (linear and flushing) at distances depending on the diameter of the pipes: 150 mm - 35 m; 200...450 mm - 50 m; 500 and 600 mm - 75 m; 700...900 mm - 100 m; from 1000 to 1400 mm - 150 m; from 1500 to 2000 mm - 200 m; over 2000 mm - 250–300 m.

The dimensions of the wells in the plan at the turns of the pipelines are determined from the condition of placing the turning trays in them. On pipelines with a diameter of up to 150 mm and a laying depth of up to 1.2 m, it is allowed to arrange wells with a diameter of 700 mm. With a network laying depth of more than 3 m, the diameter of the wells must be at least 1500 mm.

The well (Fig. 10.5) consists of a working part, which makes it possible to carry out work in it, a neck designed to be lowered into the working part, and a hatch. The height of the working part of the well (from the shelf or platform of the tray to the ceiling) is assumed to be at least 1.8 m. In the working part of the well, installation of steel brackets or hinged ladders for descending into it should be provided, and on pipelines with a diameter of more than 1200 mm with a height of the working part of more than 1500 mm - fencing of the working area with a height of 1000 mm.

The manhole tray shelves should be positioned at the top of the larger collector pipe. In wells on pipelines with a diameter of more than 600 mm, it is allowed to arrange work platforms on one side of the tray and shelves with a width of at least 100 mm.

Rice. 10.5.

1 - bottom plate; 2 – wall ring with holes; 3 - a tray made of concrete; 4 - tray shelf; 5 - floor slab; 6 - wall ring of the neck; 7 - road slab with a niche for a hatch; 8 - staples; 9 – fencing

The working part of the well is covered with a plate with a hole with a diameter of 700 mm, on which a neck of rings with a diameter of 700 mm is installed. The neck is closed with a hatch located in the niche of the road slab. Hatches are installed flush with the surface of the carriageway with improved coverage; 50 ... 70 mm above the ground in the green zone and 200 mm above the ground in an undeveloped area.

When sealing pipes in the walls of wells (Fig. 10.6), the density of the connection, water resistance in conditions of water-saturated soils, and the possibility of independent settlement of the walls of the wells must be ensured.

They connect pipes of different diameters of a separate drainage system in wells, as a rule, but at the calculated water levels (Fig. 10.7, a), and in rain and general alloy systems - along the pipes of the pipes (Fig. 10.7, b).

Rice. 10.6.

1 – wall ring; 2 – waterproofing of the inner surface; 3 – class B concrete embedment; 4 - steel pipe (case); 5 - tarred rope; 6 – pipe; 7 - tray; 8 – bottom plate; 9 – crumpled clay waterproof lock

Rice. 10.7.

a - according to the calculated water levels; b - along the shelygam of pipes of different diameters

Sanitation rates, coefficient of uneven inflow and determination of estimated wastewater costs

When designing a sewerage system, it is necessary to know the estimated costs of domestic wastewater, which are dictated by the number of residents living in the settlement in question, and the production wastewater costs established at the time of the prospective development of the settlement and the development of the full design capacity of production. These data are provided for by a promising general project of a settlement and industrial enterprises, which contains the following information: economic importance a settlement in a given district or region; data on the zoning and development of industry, climate, water bodies, terrain, geology, hydrogeology, existing and planned residential areas, the boundaries of the territory from which wastewater is required to be discharged; information on the location and size of the population by years of development in the future, the degree of improvement of residential areas, the mode of operation and technology of industrial enterprises, the hydrology of reservoirs, the conditions for water use and other data necessary for drafting a sewerage system for a settlement and a technical and economic assessment of the adopted solutions.

The calculated specific average daily (per year) disposal of domestic wastewater from residential buildings should be taken equal to the calculated specific average daily (per year) water consumption (SNiP 2.04.02–84) without taking into account the water consumption for irrigation of green spaces.

The specific average daily household and drinking water consumption in settlements per inhabitant (for a year, l / day), when building buildings equipped with internal water supply and a sewerage system, is given below:

The estimated average daily water consumption for household and drinking needs of the settlement (in m3 / day) will be

where q g - specific water consumption; Ν well – the estimated number of residents in residential areas with varying degrees of improvement.

Specific water consumption to determine the estimated flow rates of wastewater from individual residential and public buildings, if it is necessary to take into account concentrated costs, can be taken but SNiP 2.04.01–85.

The estimated concentrated costs of industrial wastewater from industry and agro-industrial enterprises and the coefficients of uneven inflow are determined on the basis of technological data.

The estimated average daily wastewater consumption in a settlement is determined as the sum of household wastewater from residential and public buildings and industrial enterprises, industrial and rainwater runoff. Wastewater consumption from local and domestic industries serving the population, and unaccounted expenses are taken in the amount of 5% of the total average daily water discharge of the settlement.

Estimated daily consumption of domestic wastewater per day of the largest and smallest inflow QCVT (in m3 / day), is determined as the sum of the products of the average daily (per year) wastewater flow rates by the coefficients of daily uneven inflow To day :

Estimated second maximum and minimum wastewater flow rates should be determined as the product of the average daily wastewater flow rate (for the year) (in l / s), by the total non-uniformity coefficient K gen (Table 10.1):

Table 10.1

General coefficient of non-uniformity of wastewater inflow depending on the average wastewater flow

Note. For intermediate values ​​of the average wastewater flow rate, the total non-uniformity coefficients should be determined by linear interpolation.

When calculating the drainage network, it is convenient to determine the estimated costs by the runoff modulus q Q . The runoff module (specific consumption) is the average estimated flow rate (in l / s), from 1 hectare of the territory from which it is necessary to drain wastewater:

where q 1 - the rate of water disposal per person per day, l; R – population density, people/ha.

The estimated flow rate of wastewater from the area is found by the formula

where F- the area of ​​the territory from which wastewater is discharged, with the same population density, ha.

When determining the estimated costs, the drainage network is divided into calculated sections ( 1–2, 2–3 etc. in fig. 10.1, a, b).

The design section of the network is the pipeline of the drainage network between two points (wells), in which the estimated flow and slope i tr is taken constant, and the movement of the liquid is uniform.

The length of the calculated section is taken equal to the length of the quarter or section of the pipeline from one side connection to the next.

The estimated flow rate of the site is determined as the sum of the costs of the incidental flow coming into the calculated plot from residential buildings located along its length; transit - from the higher quarters; lateral - from the attached side lines; concentrated, entering the settlement area from individual large water consumers (industrial enterprises, baths, laundries, etc.).

Associated flow is variable for the considered settlement area. It increases from zero at the beginning of the site to its full value at the end as the yard and intra-quarter networks are connected. To simplify the calculations, it is conditionally considered that the associated consumption from residential areas arrives at the starting point of the site in the amount q tlh s. For example, for the calculated area 1–2 (see Fig. 10.1, b) associated flow rate (in l / s) will be

where F is section "a" of the area of ​​the first quarter adjacent to the calculated section.

In the scheme of Fig. 10.1, a associated cost for the site 1–2 will be equal to

where F 1 - the area of ​​the quarter adjacent to the calculated area.

The associated expense of the upstream section is the transit expense for the downstream. For example, for the calculated area 2–3 (see Fig. 10.1.6) the estimated flow is equal to the transit flow coming from the section 1–2, plus associated consumption from area 3a.