The food processing industry, along with other industries such as medical and pharmaceuticals, has the necessity for clean rooms that can monitor particle count, type, and size, and therefore require dust controls systems to remove potentially dangerous particles from the air that can cause an explosion and are also necessary for the breathing safety of employees. In essence, dust control is essential for maintaining workplace safety.
So, how do dust control systems work?
Simply put they work by capturing particles and accumulating them in a collector until safely disposing of them, somewhat like a large and powerful vacuum cleaner.
Fans create a suction that draws the particles suspended in the air to the collector via ductwork. In the collector, the contaminated and clean airs are separated. For example, a system will push the contaminated air into the top of the collector and once inside will force it downward to the bottom. The contaminants hit the sides of the collector and then fall to the bottom while the clean air is pushed out and into another filtration system to collect the finest particles.
Why is dust control so important?
The twin threats in a food processing environment are deflagration (combustion that propagates through a gas) and disease. Both threats are caused by a fine powder of particulates that accumulate in the air within these facilities. The most efficient way to neutralize both risks is to remove these suspended particles from the atmosphere.
Deflagration is an explosion caused by the extremely rapid transfer of heat through the air and factories. Processing plants that allow suspension of particulates to propagate are setting up the environment for such an explosion. In fact, a secondary explosion usually follows, precipitated by the rapid rise in pressure caused by deflagration. As the explosion picks up fuel from the air and spreads, it can become even more destructive than the initial detonation. The entire facility can be levelled, resulting in massive loss of life and material. Dust control removes particles from surfaces and the surrounding atmosphere and significantly minimizes this danger.
In every heat explosion, there are three elements present, known as the “fire triangle”, these are oxygen, heat and fuel. When these elements are present, an explosion occurs. If suspended particulates accumulate in the air, their combined surface-area-to-volume ratio makes them highly combustible and even what may seem to be ordinary, everyday substances can become a risk.
Of course, removing heat sources is very costly and often difficult. The most effective way to minimize the risk of deflagration is to remove the elements of dispersion and fuel from the surrounding environment. This is most easily accomplished through dust control.
So, neglecting dust can have explosive consequences. Substances regularly used in industrial cooking and baking including flour, sugar and various powders, all have the potential to explode.
When substances are finely ground inside baking and cooking appliances they can create a dust cloud. This dust, when suspended and mixed with air, can cause large and even fatal explosions.
Bag tip units and bulk silo venting equipment is sometimes overlooked, but it is vital in the food manufacturing industry. These systems help reduce the amount of dust that is left over, dust that has the potential to cause explosions in the future.
Prevention is better than cure so actions such as: –
- Looking at where equipment is positioned and ensure there are no leakage points around handling systems that produce dust.
- Vacuum clean-up systems can also be used to ensure vessels and equipment are left scrupulously clean.
Let’s also take a look at the health risks for workers in a food processing plant. We know that suspended particles are readily inhaled and so removing powders from surfaces and air will minimize the health risks associated with working in these plants. Although the lungs can expel most powders to some extent, they cannot eliminate them entirely. Over time, these substances collect in the lungs and may result in irreversible health conditions. So once again, dust control is critical for safeguarding employee health.
There is something known as “Farmers lung” which can be caused from particles expelled by grains. Farmer’s lung can cause fibrosis, or scarring, of the lungs. This results in reduced breathing capacity and makes it more likely that cancer and other chronic diseases will develop. While removing a source of heat may help curtail deflagration to a point, it will not eliminate the health risks caused by suspended particles. Only dust control, performed through filters and vacuums, can accomplish this.
Prevention and Maintenance
It goes without saying that neglecting dust can have serious consequences and substances that are commonly found in the food processing industry such as flour, sugar and various powders, all have the potential to explode and so preventative maintenance is vitally important.
What sort of maintenance requirements are needed for dust control systems?
The following maintenance activities need to be carried out:
- The collector and filters must frequently be cleaned to enable the machine to run properly.
- The fan and electrical switches and boxes have to be frequently cleaned.
- The cooling vents of the machinery must be kept clean as well to prevent the machines from overheating.
- There should be an inspection for leaks in the vacuum hoses or ductwork after the cleaning. Leaks make the machine less efficient and can actually spread the contaminated particles rather than collect them.
Employee Health & Wellbeing
Employees are the most valuable asset to any business. As well as a moral obligation to protect a company’s workforce, there is also a legal obligation.
Dust that is produced as a result of food production, can also have serious effects on the health and wellbeing of employees. Exposure to dust can cause serious skin conditions and even occupational asthma, when flour dust is breathed in. In fact, respiratory conditions among bakers are now the highest of any occupation in the country.
The HSE sets a long-term Workplace Exposure Limit of 10 mg/m3 (averaged over 8 hours) and a short-term exposure limit of 30 mg/m3 (averaged over 15 minutes). Breaching of these standards can result in severe penalties, loss of productivity due to employee sickness and even legal action.
Last year, an employee from a baking company in Southampton was awarded a five-figure sum after developing occupational asthma due to over exposure to flour dust. For small or large food manufacturers, looking after employee health by reducing dust exposure is vitally important.
Also, in late 2016, a bakery company in Stevenage was fined over £36,000 for failing to comply with the Health and Safety Executive (HSE) standards — a very real threat to smaller businesses.
The HSE is continuing its proactive assessment of food manufacturers for dust control and issuing penalties for the breaching of standards, but it is not just the threat of being penalised that means it is vital for the industry to take dust control more seriously. It should be about the what that companies go about their business. “This is the way we do things around here”.
A final word on the environment
Whilst most food products by their nature are not hazardous to the environment there is still a legal obligation to comply with emissions according to EPA.
For more information and advice on dust control, air filtration and ventilation contact us at HVDS on 01785 256976 or firstname.lastname@example.org.