Industrial food and beverage processes tend to use large quantities of water. As a result, scaling on equipment can become such a problem that it no longer operates properly.
These mineral deposits mainly consist of magnesium and calcium carbonate, but can also include small amounts of oxalates, phosphates, silicates and sulfates.
There are a number of conditions that can cause minerals to precipitate, the most common being:
- High mineral content; this usually refers to the hardness of the water used.
- Any changes that modify the solubility of minerals in water, such as:
- An increase in temperature
- An increase in pH
- A change in pressure
- Poor circulation, which reduces turbulence and increases the likelihood of insoluble particles building up on surfaces.
In such conditions, it’s not surprising to see heavy buildup of insoluble residues on equipment such as pipes, heat exchangers, dishwashers, pasteurizers, bottle washers, cooling towers and so on.
Clogged equipment can have serious consequences. For example:
|Scale buildup in a bottle washer|
- Scale buildup increases the weight of equipment. In a bottle washer, for example, scale buildup on cells and chains increases their weight, causing premature wear and making them more likely to break. It also takes more energy to operate a chain that’s been weighed down by scale.
- Scale buildup in a heat exchanger typically leads to lost efficiency, as the layer of deposits becomes a thermal insulator, making energy transfer less efficient. For example, only 1/16″ of buildup in a kettle will reduce efficiency by approximately 12%.
- Clogged pipes reduce the capacity of transmission lines. To obtain a flow rate similar to that under original conditions, pressure has to be increased. However, this can lead to serious consequences, such as increasing the likelihood of major damage and causing certain equipment to blowout due to abusive operating pressures.
|Classic case of clogged pipes|
- In extreme cases, pipes can become so blocked that descaling is not even possible because the descaling solution cannot circulate through them.
- The presence of porous mineral deposits also encourages biofilm growth, increasing the risk of microbial contamination.
Properly using sequestrants in alkaline cleaning or using acid cleaning cycles can prevent and even eliminate the buildup of these deposits.
Where no preventive measures are in place, mineral buildup can become so problematic that expensive remedial treatments are needed to solve the problem.