Chilled water systems are widely used in concrete batching plants for construction purposes. This method shows many outstanding effects, significantly improving the quality of concrete when used in practice.
What do you know about chilled water system for mixing concrete?
– Water-cooled concrete mixer is one of the most prominent and important applications of the chiller system
– The use of water-cooled concrete mixes can minimize cracks due to temperature differences during solid concrete, improving the quality and longevity of concrete.
Adjusting the water temperature to the appropriate level also helps to slow down the hardening of the concrete mixture after mixing, facilitating the transport of ready-mixed concrete to the construction sites in the farther, spend more time moving.
Temperature and shipping time respectively:
With Temperature Transport Time
3 oC -> 20 oC 30 Minutes
19 oC -> 10 oC 60 Minutes
9 oC -> 2 oC 120 Minutes
When to use chiller water cooling mix concrete?
During the use of construction concrete, there are two most common cases that require application to the chiller system:
Case 1: High temperature summer environment
– Summer water sources have higher temperatures and do not guarantee the quality of concrete mixing. Especially in tropical climates, this temperature is usually around 33 -34 C, making it easy to crack when solidifying.
– Use chiller with water cooling card in concrete mixing process, which helps the concrete mixture has better structure and adhesion.
Case 2: Cooling fresh concrete
– When transporting fresh concrete away, chiller can reduce the water temperature as well as the mixture, slowing down the hardening of fresh concrete.
Calculate the water temperature used for the system
According to the calculation formula
An average of 185 liters of water is needed.
Formula for cooling water:
Q = Water volume x At x Q amount of water
For example, in the case of freezing for 100 concrete piles, the water used is 18.5 cubic meters, the temperature falls from 30 ° C to 5 ° C for 1 hour.
Q = 4.186 x (30-5) x 18.5 / 3.6 = 537.7847 Chilled kw.
Using 10% reserve, we have Qchiller = 537.7847 x 1.1 = 591.56317 Kw cold
Chiller rated power is 170 HP
In experience use
Cooling in high temperature environment:
– 15 blocks of concrete use 3 water blocks, lower the temperature from 30 ° C to 5 ° C in 1 hour => use 5HP chiller
– 100 blocks of concrete use 20 cubic feet of water, lower the temperature from 30 ° C to 5 ° C for 1 hour => use 33HP chiller
Cooling of fresh concrete
– 15 blocks of concrete use 3 blocks of water, lower the temperature from 30 ° C to 5 ° C for 1 hour => use 25Hp chiller
– 100 blocks of concrete use 20 cubic feet of water, lowering the temperature from 30 ° C to 5 ° C for 1 hour => using a 167 Hp chiller.
Two main types of cooling systems
Type 1: Good quality water source, can be used directly for the system, the temperature in the range of 6-28 degrees Celsius
Type 2: The water quality is not good, contains temporary, dusty sand easily clinging to chiller to reduce the efficiency. It is recommended to use an intermediate heat exchange PHE, run 25% ethylene glycol, use water in the range of 5-28 degrees Celsius
Parameters required for the design of the concrete batching plant
Before the design of a water cooled chiller plant, the user should determine the following parameters:
– The amount of cold water used for each batch
– Water temperature (determine the unit of measurement will be used uniformly in design and use)
– Water supply and quality
– Time for each batch, number of tanks in the system