PROCESSES
Pirobloc designs, manufactures and installs boilers and thermal oil circuits for the industrial laundry sector. We provide customised, maximum efficiency water heating solutions for industrial laundries, which can typically be found in:
THERMAL OIL SOLUTIONS FOR INDUSTRIAL LAUNDRIES
We provide thermal oil solutions for the heating of industrial laundry facilities, such as:
- Laundrettes
- Hotels
- Residences
- Hospitals
Industrial laundry is one of the characteristic applications of thermal oil boilers, as they are the most efficient and reliable alternative for supplying the necessary temperature for ironing, drying and washing processes.
By means of a closed thermal fluid circuit, the thermal oil heated in the boiler is distributed to the various consumers and laundry machinery, such as calendars, dryers and drying tunnels.
The same thermal oil boilers are used for producing steam in car washers and/or generating hot water for washing machines. When it comes to the hotel industry, they can also produce the domestic hot water needed for the hotels themselves, in addition to heating swimming pools and/or saunas.
Thermal oil heating systems installed in industrial laundries offer higher productivity and efficiency per unit of surface area than other solutions available on the market.
OPERATION OF THE SYSTEM
In industrial laundries it is common to find several boilers, dryers or DHW accumulators at the same time. In this case, there are usually several thermal oil boilers connected in the same circuit, and you can have equipment in reserve in case anything stops working at any point. In the case of multiple boilers, operation is fully automatic and only the outlet temperature needs to be selected. Once this value has been selected, management of the boiler(s) is fully automatic. Both gaseous and liquid fuels can be used, and they can even be mixed.
Pirobloc has designed and installed thermal oil heating solutions for numerous hotels and industrial laundries.
The usual layout of a heating system with thermal fluid boilers is as follows:
The following elements are shown in the diagram from left to right:
- Heat exchanger for the production of hot water, whether it be for domestic use or heating. Hot water storage tank, normally for DHW production and storage. It is a tank made from stainless steel where hot water is stored at a temperature of approximately 70 ºC. Thermal oil circulates through a bundle of tubes inside the tank, which is responsible for increasing and maintaining the temperature of the tank.
- Steamer: this device generates the steam required for washing machines or tunnel washers using thermal oil.
- Collection tank: capable of holding all the oil required for the circuit.
- Expansion tank equipped with a cold sealing tank or a layer of inert gas, which largely eliminates oxidation of the heat transfer fluid.
- Boiler (in red): thermal oil heating equipment.
- Calendar: this industrial ironing machine works directly with thermal oil and with a temperature difference of only about 5ºC between inlet and outlet. This makes it highly productive as it allows high ironing speeds with high quality.
- Dryer: like the previous piece of equipment, this also works directly with thermal oil.
BEST HEAT TRANSFER FLUID FOR INDUSTRIAL LAUNDRIES
In an industrial laundry, thermal oil-based heat transfer systems are generally used to transport heat, for example, when using calendars, mangles or ironing machine. In this context, thermal fluid systems are preferable to traditional steam-based systems, as they can easily be heated up to 230°C compared to 180°C for steam-based systems.
Finally, thermal fluid systems reduce common problems in the laundry industry that would be magnified with a steam-based system, such as corrosion, condensate return and steam trap maintenance.
Heat transfer fluids for industrial laundry applications must have excellent thermal stability and rust resistance to operate efficiently at these high temperatures.
The use of thermal oil as a heat transfer fluid in laundries offers important advantages for the owner:
- It is easy to generate 4 bar steam
- No condensate return or water treatment
- Simple installation and fitting
- No hazards from high-pressure steam
- No condensate or energy losses
- No corrosion
Maintenance of the heat transfer fluid
In addition to carefully selecting the correct type of oil for industrial laundry equipment, managers of these facilities should perform periodic sampling to assess the condition of their thermal fluid. The heat transfer fluid needs to be analysed and maintained on a regular basis.
THERMAL OIL SOLUTIONS VS STEAM SYSTEMS
There are a number of issues common in steam systems that are eliminated by supplying heat through a thermal oil boiler instead, such as system corrosion, steam trap maintenance and condensate return. There are also no discharge or water treatment problems, and operating costs are significantly reduced due to the efficiency of the system.
There are many reasons why a thermal fluid boiler heating system is more efficient and cost effective than a steam heating system.
Productivity
While steam systems generally operate at 350°F, thermal oil systems can effortlessly deliver 450°F, with the pump discharge providing just enough pressure to overcome pipe friction.
In comparison, a 3-roller oil-heated ironing machine with parallel flow is capable of providing approximately the same output as a 5-roller steam-heated unit.
The low pressures common in thermal oil systems allow the use of steel rollers in place of cast iron rollers, which are required for steam systems. Not only does this provide cost savings but heat transfer is also more efficient with steel, and there are less rollers so you can save valuable floor space.
Maintenance
Thermal oils do not corrode the materials commonly used in laundry systems. In fact, the oils actually provide a protective coating to the metals used in the system and also lubricate the moving parts better.
With steam systems, corrosion is considered unavoidable, so reducing corrosion as much as possible is one of the main objectives of these systems. This is mainly done through water treatment, which is maintenance-intensive and costly. Due to corrosion, traps and other components must be continuously maintained.
Environmental Concerns
Another of the major advantages of installing a thermal fluid solution is that these systems do not generate any type of purges because it is a closed circuit.
Water used in a steam system must be treated to reduce corrosion and lubricate the system, in addition to several other requirements. In certain cases, the chemicals used are considered regulated and/or hazardous waste. System leaks and purges must be closely monitored, and water from the system must not be allowed to flow into waterways or enter the facility’s general drains.
Operational costs
Steam systems lose energy through evaporation, condensation, deaeration and purge cycles, while thermal oil systems operating at higher temperatures use less fuel due to the absence of these losses.
Labour costs
Thermal oil systems operate at pressures dictated by the pump discharge, the static head of the expansion tank and the vapour pressure of the fluid (generally well below atmospheric pressure). All this enables low maintenance, strict temperature control and smooth operation.
A steam system operates at pressures that require continuous monitoring, resulting in higher costs for qualified personnel.
Advantages and disadvantages: overview
Advantages for the owner of a thermal oil heating plant:
- Efficient heating of washing machines, dryers and ironing machines.
- Optimum conditions for the ironing machine to process different fabrics: operating temperatures between 180 and 220°C with precise regulation.
- Some washing machines can be connected directly to the thermal oil system.
- The washing machines can also be connected to a steam generator of only 4 bar without any recycling of condensate.
- Easy system start-up. Restarting after long breaks is also easy because the thermal oil system is always full of thermal oil, which protects the entire system against corrosion.
Advantages of thermal oil heating plants compared to high-pressure steam heating plants:
- Simple installation and fitting
- 90% overall efficiency vs. 70% in steam systems
- No corrosion and lower maintenance costs
- Increased efficiency in the heating plant
- Pressure-free system
- Increased safety and longer life
Disadvantages of a steam heating plant:
- Danger of high pressure in the system
- Regular inspections, requirements and placement agreements
- Consumption of chemical products
- Condensate and energy losses
- Daily maintenance work
- Corrosion
- The system requires more valves and equipment, which results in a higher investment in the steam heating plant
- It makes no sense to produce high pressure steam to heat only the ironing machine because all the other machines do not need such a high pressure
- Due to its dangerous nature, today the use of high pressure steam is only recommended in industries that truly need it
- Condensate recycling and water treatment require expensive systems.
