Interactive dry-deck design study

Interactive dry-deck design study

From the organization of the playground to the calculations of water circulation, drainage and exploitation control

An interactive dry fountain is a space where the movement of water and the presence of people are part of a shared experience. Children move between the fountains, companions sit around, and the surface of the field can be used for other activities after the spraying stops. The quality of this experience depends on the coordination of urban design, facilities and daily management.

In the previous discussions, a sample pond fountain was examined. In this chapter, a hypothetical study for water feature with the possibility of playing and direct contact of users with water is presented. The numbers are the educational assumptions of this study and are not considered the actual product or project specifications of GSO; Converting them into an executive plan requires location information, selected equipment, and the approval of responsible designers.

46–1. Determining the user before choosing the equipment

"Dry floor" describes the way the fountain is set up: the nozzles are on the floor level and there is no obvious basin in the area. This title alone does not indicate that the collection is designed for children.

The project definition must specify:

• Are people allowed to enter the spraying area?

• Is direct contact with water and use by children anticipated?

• Who will be responsible for reopening, water monitoring and decommissioning?

• What other uses does the area have during shutdown?

The CDC also differentiates between a decorative water feature and a water play space, and emphasizes management commensurate with public access. In this study, interactive usability is part of the design basics from the beginning. CDC Guide to Interactive Water Fountains ^[305]

46–2. Definition of sample project and organization of space

The hypothetical project is located in an urban public space and includes a play area, companion viewing area, and facility room.

The area of 64 square meters is only the water collection surface in the example. Peripheral paths, seating, service access and distance from buildings should be designed separately. Also, the allowed number of users is not obtained from the area alone; The operating capacity must be in harmony with the health facilities, monitoring and capacity of the treatment system.

Figure note from the source manuscript

Figure 1-46: Conceptual plan of the project

8 x 8 meter area plan showing 16 nozzles, four color groups, direction of water movement on the floor, collection entrances, companion seating area and independent access path to the facility. Subtitle: "Educational plan; The final placement is subject to accessibility, wind and site requirements."

46–3. Calculation of the flow rate of nozzles

The discharge of each group is equal to:

$Q_{group}=4\times 0.6=2.4m^3/h$

If all nozzles work at the same time:

$Q_{spray,max}=16\times 0.6=9.6m^3/h$

This calculation relies on the constant flow rate of each nozzle at the desired working pressure. Opening and closing groups can change network pressure; Therefore, adjusting the pressure and balance of the groups should be a part of the design.

The height, shape and intensity of the water impact should also be determined based on the selected nozzle and the use of the game. The low height of the fountain alone does not prove that it is suitable for contact with the body.

46–4. Choosing a water management method

There are two main options for initial consideration: single use of supplied water and recirculation of water after treatment. Vortex introduces both approaches in its water management solutions. The choice among them depends on water availability, permitted disposal route, operating hours and maintenance facilities. Vortex water management solutions ^[306]

If in the present example, all the nozzles work for six hours non-stop with disposable water, the volume of water supply will be:

$V_{daily}=9.6\times 6=57.6m^3/day$

This number corresponds to the same hypothetical scenario. Periodic activity or activation by the user changes it.

To continue the study, the recycling system is selected. Fresh water consumption in this system should be calculated from evaporation balance, water exit with users, outside spraying, equipment washing and necessary evacuations. It is not possible to declare the actual saving percentage from the flow rate.

46–5. Water volume and filtration flow rate

The effective volume of the system includes tank water, pipes and equipment. In the basic state:

$V_{system}=12+0.4=12.4m^3$

For comparison, clause 4.12.8.6.3 of the 5th edition of the MAHC specifies a minimum operating volume of a collection tank of 11,356 liters. The assumption of 12 cubic meters in this example is more than that; But this comparison does not confirm the complete compliance of the plan. The MAHC in this book is a technical reference and does not replace the regulations in force at the project site. MAHC text, 5th edition ^[307]

CDC recommends a nominal circulation time of 30 minutes or less for interactive fountains. By choosing 30 minutes for this example:

$Q_{treatment,min}=\frac{12.4}{0.5}=24.8m^3/h$

CDC Operating Manual

In order to check the change of water level, we assume the limit of the allowed stock of this study in the game mode to be 15 cubic meters:

$Q_{design}=\frac{15}{0.5}=30m^3/h$

Therefore, the flow rate based on the equipment review will be 30 cubic meters per hour. With this flow rate, the circulation time in normal inventory is equal to 24.8 minutes.

This result is only volumetric circulation control. Adequacy of disinfection, contamination load, mixing and actual performance of equipment should be checked separately.

46–6. Water path and display change management

In the proposed conceptual arrangement, the main path is as follows:

Collection tank → Primary filter → Circulation pump and pressure supply → Filtration → Disinfection and quality control set → Water collector ready for spraying → Nozzles → Gravity collection from the floor → Tank

The direction of movement in this expression is according to the order of reading the parts. The location of material injection, mixing, contact time and sampling should be determined in a detailed process map.

The basis of this arrangement is that all the water sent to the nozzles goes through the necessary steps. For the interactive water play area, MAHC states that 100% of the water passes through secondary treatment before reaching the users. Clause 4.7.3.3.2.2 in MAHC

The filtration flow rate of this example is higher than the spray flow rate. Excess water, after completion of the treatment process, returns to the reservoir through a controlled return:

The unit of all the numbers in the table is cubic meters per hour.

The return route must have the capacity to pass the entire flow. Changing the number of groups should not cause a decrease in the purification flow or an unauthorized increase in the pressure of the nozzles. The energy consumption of this arrangement should also be compared with other engineering options in the detailed design.

Figure note from the source manuscript

Figure 2-46: Schematic of the water process

The path of collected water, purification steps, collector nozzles and the return of purified water should be displayed with specific colors. The flow rates of 30, 9.6 and 20.4 cubic meters per hour should be inserted on the relevant routes. The direction of the arrows must be clear.

46–7. Selection of pumps and disinfection equipment

To select a pump, a flow rate of 30 cubic meters per hour should be combined with the required head:

$H_{pump}=H_{static}+H_{nozzle}+h_{pipes}+h_{filter}+h_{treatment}+h_{control}$

In this regard, the drop of the filter in the permitted state before washing and the actual drop of the filter set are important. Choosing engine power without this information is not reliable.

The capacity listed on the product name is not enough to check a UV unit. In the inquiry of this project, the valid performance range of the device in the desired flow rate, the UV transmission quality of the water, the condition of the lamp performance loss and the required disinfection criteria should be requested.

In the MAHC basis, the secondary treatment of the aqueous game space is defined to reduce at least three logarithms of Cryptosporidium per pass. Verification of this performance is dependent on validation and actual working conditions. Clause 4.7.3.3 in MAHC

The project plan should also cover disinfectant residual and pH control; The UV status light being on is not the only permission to start the game.

46–8. Calculation of foam collection discharge in rainfall

For a numerical test, we assume a rainfall intensity of 120 mm/h and a surface runoff coefficient of one. This number is not the design rainfall intensity of any specific city.

Assuming only direct rain on the surface of 64 square meters:

$Q_{rain}=CiA$

$Q_{rain}=1\times 0.12\times 64=7.68m^3/h$

At the same time as this rain with the activity of all the nozzles:

$Q_{floor}=9.6+7.68=17.28m^3/h$

$Q_{floor}=4.8L/s$

This discharge is to check the skimmers and the skid collection path. The facility's controlled return goes directly to the tank and does not pass through the floor.

Determining the diameter of the pipe still requires slope, outlet level, half-full flow, inlet capacity, and the possibility of clogging. Also, the runoff of the surrounding area should be away from the playing area in the design of the area; Entering an additional catchment area changes the calculation.

46–9. Control of the water intake space in the tank

Volume of direct rain in 20 minutes:

$V_{rain}=7.68\times \frac{20}{60}=2.56m^3$

We assume that after stopping the spraying, a maximum of 0.20 cubic meters of water will return to the tank from the lines and surface. In a conservative review of reservoir acceptance:

$V_{acceptance}=2.56+0.20=2.76m^3$

If the initial reception space is only two cubic meters:

$2.76-2=0.76m^3$

So this option is not enough for the assumed event.

To continue the study, we assume that the reception space is 3.5 cubic meters. Remaining margin in this event:

$3.5-2.76=0.74m^3$

This value is not the final nominal volume of the tank. The control levels, the volume below the operating level, the free space above the water and the overflow path should be determined in the tank section.

The important thing is that the water returned from the pipes does not increase the balance of the entire system; Only its location changes. So the total balance after rain:

$V_{afterrain}=12.4+2.56=14.96m^3$

And the travel time with a flow rate of 30:

$T=\frac{14.96}{30}\times 60=29.92min$

This volume has almost reached the assumed ceiling of 15 cubic meters. The numerical sufficiency of the circulation time does not allow the game to continue in the rain or after the entry of pollution; Weather conditions and water quality have independent criteria.

Figure note from the source manuscript

Figure 3-46: Reservoir training course

Base level, acceptance space of 3.5 cubic meters, warning level, overflow, free space and return route of the lines should be specified. Subtitle: "Operating water volume, acceptance capacity and structural volume of the reservoir are three different values."

46–10. Floor, nozzle housing and repairability

In the coordination plan of this project, for each nozzle, the final level, cap opening range, cable and pipe route, and part replacement method should be specified. The surface around the equipment must maintain the necessary continuity for the movement of users and the drainage of water.

In the SplashCan product, OASE has coordinated water connection, cable passage and installation position adjustment in one compartment. This example shows that installation details should be designed at the same time as the equipment. Introducing SplashCan from OASE ^[308]

Dry floor nozzles, related equipment and chamber packages have also been introduced on the GSO website. To be selected in this study, the map and data of the proposed model must be received. GSO urban fountain equipment ^[309]

In the specifications of the floor, the term "anti-slip" is not enough; The method of evaluating the wet surface, cleaning ability and suitability for users should be determined. Access to service compartments should also be closed and controlled during public presence.

46–11. Permission to start and stop spraying

The user command in this project is the request to start the game. The system must confirm the permitted conditions before executing it.

Stopping the game doesn't necessarily mean stopping all cleaning; The response of each equipment should be defined according to the cause of the stop.

Electrical design should also consider protection, bonding, power supply, cabling and maintenance access. Placing "24V" or "IP68" on a part does not guarantee the safety of the entire assembly.

46–12. Opening schedule and daily management

For this project, the daily reopening sheet should record the result of water control, surface inspection and facility condition verification in one location.

CDC recommends that treatment and disinfection performance be checked prior to reopening, and that residual disinfectant and pH be monitored prior to start-up and every two to four hours during operation. Recording of actions and training of employees is also included in this guide. CDC interactive fountains operating manual

The collection specific program should specify the name of the person in charge, the acceptance limits, the measurement method and the necessary action after the adverse result. The automatic display must be adapted to the independent control method foreseen in the maintenance plan.

After unusual contamination is observed, re-opening should not be done simply by the apparent clarity of the water; The conditions for returning to service must be defined in the operating instructions.

46–13. Rainfall, shutdown and change of use of the field

This area may be a place of passage, cleaning or urban activity during off hours. The water management plan should have a clear path for these situations:

Water from washing the floor;

• Contaminated runoff or rainfall;

• Water overflow and draining the tank;

• Water obtained from washing the purification equipment.

The route of disposal or reuse must be determined with the approval of the responsible authority of the project. Discharge to the street or surface water network should not be a design default.

To change the situation from playing to washing, in this plan, the general spraying is first stopped; Then the collection route is changed according to the instructions. Restarting will depend on confirming the correct condition of the valves, cleanliness and water quality.

46–14. Purchase details and required documents

The inquiry of this project should go beyond the number of nozzles and pump power.

Supplying a dry floor package alone does not prove that it covers all the requirements of a water playground. Evaluation should be done based on the documents of the proposed collection.

46–15. Project delivery tests

Tests should show the behavior of the set in different conditions.

Error simulation should be controlled and done without creating real risk. For example, the low water protection test can be done by simulating the signal and does not need to run the pump dry.

Figure note from the source manuscript

Figure 46-4: Delivery test from company archive

Image of the technician measuring the flow or recording the tank level, along with a realistic view of the floor condition after the stop. The specifications of the actual project should be included in the subtitle, and the image should not be introduced as a hypothetical sample implementation of this chapter.

46–16. Study results sheet and design completion

The calculation output of this chapter to continue the design is as follows:

Before issuing the executive plan, rainfall intensity of the site, disposal route, equipment curve, network calculations, disinfection capacity, structural and electrical design, and operation plan must be completed. Tank volume and control levels should also be matched with actual line inventory and transient condition analysis results.

The final delivery documents should include as-built drawings, recorded settings, test reports, opening and closing instructions, and user responsibilities. These documents will be the basis of the daily management of the space that people see as a few simple fountains on the square.