What is cycle of concentration in cooling tower

CYCLES OF CONCENTRATION is the number of times the concentration of total dissolved solids (TDS) in cooling tower water is multiplied relative to the TDS in the makeup water. Because evaporation of pure water leaves dissolved solids behind in the system water, TDS increases over time as the tower operates.

What is meant by cycle of concentration in cooling tower?

A key parameter used to evaluate cooling tower operation is “cycle of concentration” (sometimes referred to as cycle or concentration ratio). This is determined by calculating the ratio of the concentration of dissolved solids in the blowdown water compared to the make-up water.

What is cycle of concentration in boiler?

Cycles of Concentration. “Cycles of concentration” refers to the accumulation of impurities in the boiler water. If the boiler water contains 10 times the level of impurities in the makeup water, it is said to have 10 cycles of concentration.

How do I calculate my cycle concentration?

It can be estimated by dividing the conductivity of the system water by the conductivity of the makeup, or by dividing the chloride of the system water by the chloride of the makeup.

How do you calculate concentration of cycle in boiler?

A boiler cycle is the number of times TDS present in feedwater can concentrate. For example, 100 TDS feedwater, cycled five times, would result in 500 TDS. Example: If boiler conductivity = 1,000 and feedwater conductivity = 100, the boiler is achieving 10 cycles.

What is COC in boiler?

Two weeks ago we talked about options for calculating the cycles of concentration (CoC) in cooling water systems. … Dividing the boiler water TDS (or neutralized conductivity) by the feedwater TDS is sufficient to give us a reasonably close value.

What is concentration cycle?

CYCLES OF CONCENTRATION. CYCLES OF CONCENTRATION is the number of times the concentration of total dissolved solids (TDS) in cooling tower water is multiplied relative to the TDS in the makeup water.

How do you calculate blowdown in a cooling tower?

1. Evaporation loss = 0.00085 Wc (T1-T2)
2. Drift loss = 0.02% water supply [for new development in eliminator design]
3. Blowdown = [ Evaporative loss – (COC – 1) x Drift loss] /(COC – 1)

How do you calculate water for a cooling tower?

1. Cooling tower makeup calculation. Water Make Up = D + E +B. …
2. Evaporation Loss = 0.00085 * 1.8 * C * Δt. C = Circulating water in. …
3. Blowdown : B = E = Evaporation Loss in. …
4. COC = Cycle of Concentration. …
5. Capacity of cooling Tower.

What is drift loss in cooling tower?

Drift is water lost from cooling towers as liquid droplets are entrained in the exhaust air. The drift loss is independent of the water lost by evaporation and may be expressed in units of lb/hr or percentage of circulating water flow. Cooling tower drift eliminators are used to control this drift loss from the tower.

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What is evaporation loss in cooling tower?

Cooling tower use water circuit to bring heat out, in this process, part of cooling water will be evaporated, this is called evaporation loss. Evaporation loss usually represents the efficiency of cooling tower and the heat of equipment.

How is water cooled in a cooling tower?

A cooling tower is a specialized heat exchanger in which air and water are brought into direct contact with each other in order to reduce the water’s temperature. As this occurs, a small volume of water is evaporated, reducing the temperature of the water being circulated through the tower.

Is cooling tower blowdown continuous?

Cooling towers, closed circuit coolers and evaporative condensers require continuous blow down or “bleed off” with added make-up water to maintain an acceptable concentration level.

What is a result increasing boiler cycle of concentration?

When the cycles of concentration are increased, a similar fuel savings is achieved. However, higher cycles of concentration also will result in less blowdown flow — thus reducing the amount of heat that can be recuperated by a blowdown heat exchanger.

How can I improve my cooling tower performance?

1. Save energy.
2. Reduce the amount of water being consumed.
3. Decrease the amount of chemicals required for water treatment.
4. Extend the equipment service life.
5. Reduce operating costs, overall.

What is TDS cooling tower?

Cooling towers are used within some businesses for process water cooling or as part of an air-conditioning system. … ‘Bleed’, ‘blow-down’ or ‘dump’ cycles – as water is evaporated, concentrations of total dissolved solids (TDS) increase which is detrimental to the efficient operation of the unit.

What should be the pH of cooling tower water?

The allowable pH ranges for different cooling towers vary. The material the tower is made from determines the ideal pH of the water as well as possible treatments against scale and corrosion. Galvanized steel’s optimum pH ranges from 6.5 to 9, but type 316 stainless steel has a broader pH range, from 6.5 to 9.5.

What is neutralized conductivity?

What is meant by neutralized conductivity? … The OH- ion has very high conductivity but is a dissociate of H2O so does not contribute to TDS. The OH- ion conductivity can be eliminated by reducing the pH to 7 or neutralizing the sample with an organic acid such as gallic or acetic acid.

How do cooling towers control conductivity?

Replacing cooling tower bleed off with fresh source water lowers the conductivity of cooling water. Side stream filtration is another way of lowering cooling water conductivity, wherein a portion of cooling water is passed through a sand filter, removing some of the solids.

How are cooling tower cycles calculated?

Cooling Tower Water Use (Make-Up) = Evaporation + Blowdown The cycles of concentration are the ratio of the concentration of TDS (i.e., conductivity) in the blowdown water divided by the conductivity of the make-up water.

What is LG ratio in cooling tower?

The L/G ratio of a cooling tower is the ratio between the water and the air mass flow rates. Cooling towers have certain design values, but seasonal variations require adjustment and tuning of water and air flow rates to get the best cooling tower effectiveness.

What is the evaporation rate of a cooling tower?

Therefore, every tower ton (15,000 BTU/hr) requires approximately 1.8 gallons of water evaporation, or . 03 gpm/ton. As water evaporates in a cooling tower system, the water vapor enters the atmosphere while any dissolved solids remain behind, building concentration in the remaining water.

What is cooling tower capacity?

The cooling tower’s capacity is the product of the mass flow rate of water, specific heat, and temperature difference. This can also be expressed as heat rejected in kCal/hr (Btu/h). Evaporation loss. This is the amount of water that is evaporated during the cooling process.

How do you calculate the heat load of a cooling tower?

Heat Load – The amount of heat to be removed from the circulating water within the tower. Heat load is equal to water circulation rate (gpm) times the cooling range times 500 and is expressed in BTU/hr.

What is the formula for finding cooling tower efficiency?

Cooling Tower Efficiency = Range/ (Range + Approach) x 100 In summer the ambient air wet bulb temperature raises when compared to winter thus limiting the cooling tower efficiency.

How do you calculate evaporation loss?

To calculate evaporation losses, multiply the water surface area (in m2 ) by the corrected evaporation rate (in m) for the length of time your pond will be in use.

How do you calculate evaporation losses in a cooling tower?

Evaporation Loss This means T1 – T2 = inlet water temperature minus outlet water temperature (°F), with 0.00085 being an evaporation constant.

How do cooling towers lose water?

Cooling towers lose water by evaporation and entrainment, resulting in a water spray and fog on the downwind side of the tower, making any roads continually wet. This is a traffic hazard, because in certain locations, ice can form in winter.

How is cooling tower capacity calculated?

This should be expressed in Fahrenheit and is denoted as dt in the formula. Multiply 500 times the water flow rate, times the temperature difference, divided by 12,000 or 500 x q x dt/12,000. The result is the tons of capacity of the cooling tower.

Is evaporation a cooling process?

In general terms evaporation is defined as the process in which the liquid state is convverted in to gas. This process requires heat energy. … The change in temperature till the evaporation process will lead to cooling. Hence evaporation causes cooling effect.

What are three types of cooling towers?

There are three main types of cooling towers that are defined by how water or air pass through them. These types include crossflow, counterflow, and hyperbolic. There are also two varieties classified solely on airflow, known as induced draft and passive draft cooling towers.