Coiled tank

One of the most necessary and basic needs for industrial centers, hospitals, factories, buildings and swimming pools and most of important buildings is to providing them with adequate hygienic hot water that is sufficient and reliable.

To solve this problem, it is necessary to use equipment that provides sufficient hot water at the right temperature. Various equipment

has been developed to supply hot water industries, the most important of them are the double wall tank or coil tank.

The advantage of coil tank over than other sanitary hot water generators, such as a double water tank, is that it uses only one body and is fully repairable after problems such as bursting or clogging. Due to the existence of the main heat transfer (coil), inside the tank of coil tank, the heat loss is very low.

?What is coil tank

The coil tank, which is a type of indirect hot water, is a shell and tube converter.

Inside the pipes, steam or hot water provided by a cast iron or steel boiler flows and the water heats the environment around the pipes.

The thermal efficiency of the double walled tanks is approximately 95%. Coil tank has dimension parameters such as tank volume and coil thermal surfacing.

Copper coils in coil tank are made according to customer^‘s order in different thicknesses.

Copper coils requires less replacement and repair due to deterioration of copper coils and long term storage of hot water coil.

These tanks are more likely to need pickling and repair or replacement.

The advantage of U shaped coils to coil coils

Due to several discharge pipes, more hot water flows in it and as a result has high heat capacity.

In case of clogging and sedimentation in one of the pipes, the other pipes will compensate for the discharge through the faulty pipe, while in the coils with the clogging in the pipe, the coil will practically fail.

Coil tank and its advantages over double walled tanks

reliable valve installation (temperature and pressure) is or all production of hot water such as coil tanks.

The body of the coil tanks is usually made of hot galvanized sheet, but when used with a black sheet to prevent corrosion and oxidation, the inner surface of the tanks is fully covered with epoxy.

The advantage of coiled tanks over double wall tanks is the ease of repairs due to the single wall (in case of leakage) higher speed of cooling of the tank water as well as higher working efficiency due to the coil (heat exchanger) inside it.

notable point

The mechanism of heating operation of the coil tanks is the usage of heat or water heat input from the central heating boiler in the coil installed inside the tank and transfer of this heat energy to the cold water of the coil tank inlet (such as heat exchanger) to heat the incoming cold water.

Generally, calculation of the required horizontal hot water coil tank volume, thickness and type of body sheets and lenses, dimensional examination of the coil tank for entry and installation in the building engine, as well as determine the type of coil and heat exchange coil required to be done.

Calculate the volume of the coiled tank

Calculating the volume of the coil tank is usually calculated in demand for premises such as residential houses, factories, pools, etc.

In the pools, for example, by calculating the number of swimmers and the amount of consumption of 50 liters for one person, and by multiplying the number obtained by the demand coefficient (between 0.4 & 0.6), the volume of the reservoir is multiplied by the coefficient of 1,2 reserve coefficient

Demand coefficient

It is a factor that is multiplied by the number of showers and toilets use to the lack of simultaneous use of residents (in buildings). swimmers (in pools), etc.

Save coefficient

Water storage tanks may be severely depleted at peak load and offset by cold water, which in turn will cool the entire tank and boiler heat, not supplying the heat needed to balance the heat, so we multiply a coefficient called the reservoir coefficient of the obtained volume to ensure uniformity of temperature at the peak of consumption.  This coefficient varies for different applications and is generally considered to be 1,2 for pools.

To calculate the coil, a coil tank similar to the heat exchanger, the water temperature used, the boiler temperature and the flow rate of each pass are required.

Calculate the thermal coil surface used in Pars Dama in coil tank

To obtain the thermal coil level used, we divided the heat capacity by the logarithmic temperature difference of the inlet and outlet water as well as the overall heat transfer coefficient. Where in:

A:  heat level in square meters

Q: required capacity of coil tank in W

(U: heat transfer coefficient in (W/m2K

Δtm: logarithmic temperature difference

*the U number depends on the material used and the type of coil construction will vary.

Pars Dama coil tank material

The coil tank is generally made of galvanized sheet.

:If using black sheet (higher pressures) the inside of the tank will be covered with epoxy coating.

Calculate the thickness of steel sheet used in the coil tank in

*Machin working pressure

*working temperature

*Corrosion coefficient of water is based on standard of pressure vessels

Coil tanks are used both vertically and horizontally depending on their location.

Pars Dama coil tank feature

These are the advantages of coiled tanks over other sanitary hot water generators such as double walled tanks

*only one body was used

*problems such as bursting or clogging can be completely repaired

*also, due to the presence of the main coil inside the tank, its thermal loss is very low.

Pars dama suitable temperature coil tank water

The temperature of the hot water consumed usually reaches the consumer at a temperature of 50- 60  c ⁰. This water shouldn’t be stored at temperatures below 50 c ⁰ , this is due to the  growth of a bacterium called Legiona that multiplies at 25 to 50 c ⁰. Therefore, the appropriate temperature for coiled tanks is above this amount.  However, in cases where there is a temperature restriction at high water temperature, it is recommended to mix cold and warm water to avoid bacterial growth.