The article presents the results of experimental investigations of interactions between a deformable structure and a liquid. The investigations were performed on two prismatic tanks with elastically deformable top walls. During the investigations, different levels of tank filling with liquid were examined. The investigation of this phenomenon has direct reference to frequently recorded real events, such as collision of a tanker with another ship or a harbour berth, rapid braking of a road or rail tanker, etc. Recognition of this phenomenon is based on simultaneous measurements of the following parameters:

1. excited accelerations of the tank-liquid system,

2. elastic accelerations of top walls of the tank,

3. hydrodynamic pressures on the deformable top walls.

Results of life cycle inventory (LCI) and life cycle assessment (LCA) for septic tanks collecting domestic sewage were presented. The study included the whole life cycle: construction, use and end-of-life stages of septic tanks. The analyses were conducted basing on actual data concerning performance of 793 septic tanks in Żory. Environmental impact assessment of the life cycle of septic tanks was conducted with TRACi and ReCiPe methods. Greenhouse gas (GHG) emission, eutrophication, fossil fuel depletion and metal depletion indicators were calculated and determinants of LCA of septic tanks were analysed. The system boundary was from cradle to grave. It was concluded that at the construction stage, GHG emission and fossil fuel depletion indicators are determined by the amount of concrete, steel, polyester resin, polyethylene, cast iron and PCV. At the use stage, GHG emission is determined by the amount and type of electricity used to treat sewage in a wastewater treatment plant (WWTP). Untreated wastewater, introduced into the environment (leaking tanks and users discharging sewage), is a determinant of infl uence on eutrophication. Life cycle inventory and environmental assessment of septic tanks with life cycle perspective are presented in the literature for the fi rst time. The results highlight the importance of including each stage in the environmental assessment of elements of the urban wastewater system.

Water is the main source of daily life for everyone and everywhere in the world. Sufficient water distribution depends on the place and design of water tank in certain areas. Water storage tanks are relatively flexible structures and they can tolerate greater settlements than other engineering structures. Deformation of tanks may cause severe damages to tank or even loss of life and injury to people, so monitoring the structural deformation and dynamic response of water tank and its supporting system to the large variety of external loadings has a great importance for maintaining tank safety and economical design of manmade structures. This paper presents an accurate geodetic observations technique to investigate the inclination of an elevated circular water tank and the deformation of its supporting structural system (supporting columns and circular horizontal beams) using reflector-less total station. The studied water tank was designed to deliver water to around 55000 person and has a storage capacity about 750 m3. Due to the studied water tank age, a non-uniform settlement of tank foundation and movement of pumps and electric machines under tank’s body will cause stress and strain for tanks membrane and settlement of sediments. So the studied water tank can tend to experience movement vertically, horizontally or both. Three epochs of observations were done (July 2014, September 2014 and December 2014). The results of the practical measurements, calculations and analysis of the interesting deformation of the studied elevated tanks and its supporting system using least squares theory and computer programs are presented. As a results of monitoring the water storage tank, circular reinforced concrete beams and columns at three monitoring epochs. The body of water storage tank has an inclination to the east direction and the value of inclination is increased with the time.

The analysis of a solar installation operation was conducted on the example of a detached house in the Lesser Poland province in Poland. A gas boiler and three flat-plate collectors are located inside the house, which are used for heating water in the hot water tank with a volume of 220 dm3. The installation was established in 2012. The heat measured system (for solar gains) was added in 2014. In 2015–2019 solar heat gains measured per area of absorber were higher than 340 kWh/m2. During a two-week period in June 2015, the insolation on the horizontal plane and the temperature were measured in 4 different points of the hot water tank. On this basis, heat losses from the storage tank were determined, i.e. a decrease in temperature during periods with and without the consumption of hot water by the residents. During this period, a temperature higher than 80°C was observed several times in the hot water tank. In two parts of the hot water tank, rhe determined temperature decreases were used to obtain the heat loss amount. In the analyzed period (2 weeks), 9 days were observed with solar heat gains higher than 9 kWh/day. For these days, the value of heat loss from the solar hot water tank was estimated at over 6 kWh/day. This data corresponds to the actual heat demand for hot water preparation in the building at 7.3 kWh/day. The correlation between daily solar heat gains and solar hot water tank heat losses were also determined. In addition, based on the amount of heat losses, the value of the tank loss coefficient was estimated. The obtained value was compared with the manufacturer’s data and reference data.

The subject of this paper is an assessment of the accuracy of a solution based on the linear theory of elasticity describing the interaction of a cylindrical reinforced concrete tank with the subsoil. The subsoil was modeled in the form of an elastic half-space and Winkler springs. The behavior of the shell structure of the RC cylindrical tank, and particularly of the ground slab interacting with the subsoil, depends largely on the distribution of the reactions on the foundation surface. An analysis of this structure with the shell fixed in a circular ground slab was carried out taking into consideration the elastic half-space model using the Gorbunov-Posadov approach and, for comparison, the two-parameter Winkler model. Although the results for both subsoil models proved to be divergent, the conclusions that follow the accuracy assessment of a solution based on the theory of elasticity are fairly important for engineering practice.

In agriculture, the mixing of pesticides in tanks is a common practice. However, it is necessary to previse possible physical-chemical implications of this practice, which may affect the efficiency of the treatments performed. Therefore, the objective of this study was to evaluate the effects of the addition of acaricide to insecticidal spray mixtures on the formation of spray droplets and the interaction with citrus leaves. The experimental design was totally randomized, in a (2 × 3 + 1) factorial scheme for seven treatments. Factor A corresponded to the spray mixture used (isolate or in the mixture). Factor B corresponded to the insecticides tested (lambda-cyhalothrin + thiamethoxam, phosmet, and imidacloprid) and the control consisted of a spray mixture with spirodiclofen only. Nine replications were performed for characterization of the spray droplet size spectrum and four replications for the analysis of the surface tension and the contact angle. The mixture of pesticides showed positive results in terms of application safety. The addition of acaricide to insecticide spray mixtures reduced the surface tension and contact angle of droplets on the adaxial surface of orange leaves. There was an increment in volume median diameter (VMD), a significant reduction in the volume of droplets with drift-sensitive size and improvement in the uniformity of droplet size. Therefore, the addition of acaricide to an insecticide spray mixture positively influenced spray droplet formation and the interaction with citrus leaves providing better coverage and droplet size fractions with an appropriate size for safe and efficient application.

The aim of this study was an assessment of feasibility of conversion of sewage holding (SH) tanks to rainwater harvesting (RWH) tanks in Poland. Such a conversion may partly solve the problem of water scarcity for irrigation of plants in individual small gardens and reduce tap water consumption. Seven methods of RWH tanks sizing were applied to an example of a small harvesting system of the roof area equal to the garden irrigation area of 100 m² for three different irrigation doses. A new criterion was introduced to optimize the tank capacity. Economic optimization was provided for new RWH tanks and for the tanks adapted from abandoned SH tanks. Results obtained for a system sited in west-central Poland in an average year have shown that design capacity of RWH tanks varied markedly between sizing methods. The conversion of SH tanks to RWH tanks is profitable, especially for irrigation due to scarcity of water in relatively dry west-central regions. Conversion of individual SH tanks in a good technical state to RWH tanks is relatively simple and cheap. The potential increase in storage volume due to the conversion of individual SH tanks to RWH tanks could reach all over Poland 215–350 dam³ per year, and individually can save up to 18–25% of total annual water use.

Due to demand of tightness, the liquid tanks should be designed with particular care. In addition to the liquid pressure, the imposed concrete strains and thermal actions should be taken into consideration. Furthermore, the verification of the ULS in persistent design situation only is not sufficient. The crack control both in persistent situation as well as in early age transient one is necessary for determination of the reinforcement. In the beginning of the design process some assumptions, influencing the future tank performance must be made. First, the tightness class must be chosen, followed by formulation of conditions for crack width control. Next, the critical age of concrete, proper for early age transient situation should be assumed. This age determines the value of imposed strain on the one hand and the effective tensile concrete strength on the other. Then, it should be decided, if any reduction of the effective tensile strength would be applied (reduction associated with nonuniform imposed strain and reduction due to cracking under other combination of actions). Eventually, the decisions for structural analysis should be made, concerning the values of combination factors for actions both for ultimate and cracking limit state and the possible reduction of cross-section stiffness due to cracking caused by thermal actions in ULS.

The above-mentioned assumptions are listed and discussed in the paper. On the basis of the discussion the algorithm for crack control in concrete tanks is worked out and proposed. The issues are illustrated with practical example of cylindrical tank for liquid.

An effective method for the analysis of soil-structure interaction including the behaviour of cylindrical storage tank with varying wall thickness under the action of constant thermal loading is presented. Elastic half-space and the Winkler model have been used for the description of subsoil. The soil-structure interaction is described by using the power series. A computational example of reinforced concrete tank loaded with constant temperature is given. The analysis of a hydrostatically loaded cylindrical tank performed for the model incorporating elastic half-space shows decrease of radial displacements as well as substantial changes in the distribution of bending moments when compared to the Winkler foundation. Additionally, local increase of subsoil reaction around the slab circumference is observed for the case of elastic half-space, in contrast to the Winkler model. However, in the case of a tank loaded with constant temperature, the solutions for both subsoil models do not differ significantly.

This paper discusses design, evaluation, and application for the use of swirl/vortex technologies as liquid purifi cation system. A study was performed using modifi ed swirl sedimentation tanks. The vortex separators containing baffle have been studied under laboratory conditions at hydraulic load from 21 to 64 [m3/(m2·h)]. Analyzed disperser phases were municipal water and glycerol solutions of varying concentration. The pressure drop and the efficiency of purification of liquid stream were analyzed. The suspended particles of different diameters were successfully removed from liquid with the application of swirl chambers of proposed constructions. It was found that damming of liquid in the tank increases alongside liquid stream at the inlet and depends on the tank construction. The efficiency of the sedimentation tanks increases alongside the diameters of solid particles and decrease in the liquid flow rate. The best construction proved to be the one where baffle is located in the middle of in- and outlet due to the highest efficiency of the purification liquid stream for solid particles of the smallest diameter. The proposed solution is an alternative to the constructions of heavy fraction separators.

This paper investigated the problems and impacts of transient flow in pipeline systems due to pump power failure. The impact of different protection devices was presented to assure surge protection for the pipeline system. A model via Bent-ley HAMMER V8.0 Edition was employed to analyse and simulate hydraulic transients in the pipeline system, and protec-tion alternatives were studied.

Surge protection included using only an air vessel, using an air vessel and two surge tanks, and employing five air ves-sels and vacuum breaker. The obtained results for pressures, heads, and cavitation along the pipeline system were graph-ically presented for various operating conditions. Using five air vessels with vacuum breaker valve as surge protection proved to be more effective and economical against pump power failure.

Changing the flow density did not have a significant impact on the pressures.

For protection with an air vessel; it was concluded that the value 40% of the original diameter for inlet pipe diameter of air vessel, and the value of 2/3 of original pipe diameter were critical values for the transient pressures. Cast iron pipes proved to be the best pipe material for all studied volumes of the air vessel.

For protection with an air vessel and two surge tanks; as the inlet pipe diameters increased the maximum pressures in-creased and the minimum pressures decreased.

Regression analyses were performed obtaining equations to predict the pressures according to the inlet pipe diameter, the area of surge tank, and the pipe diameter.