THERMAL OIL HEATER

INTRODUCTION

TT BOILERS Thermal Oil Heaters type VTO (also called Thermal Oil / Thermal Fluid Boilers or Hot Oil Units) are developed and designed especially for quite "heavy duty" operations where no compromise on quality are accepted. These solutions are not based on low purchase price, but they are developed to ensure low over-all costs - including maintenance and operational costs herunder DIN 4754.

They are consequently made in first class material and component, and without any compromise on quality. The pressure part are designed as standard up to 40 bar pressure although operation pressure might between 3 - 10 bar.

The heaters for thermal Fluid (hot oil) are delivered complete and fully equipped units with all armatures, instrumentations and safety features.

The thermal fluid heaters are delivered as oil fired, gas fired, for dual fuel and electrical heated. The customized options are numerous and include also a free choice between the horizontal or vertical type. Min. 10 bar design pressure and capacities in the standard design up to 3000 kW, and up to 10.000 kW on request.

THE BENEFITS OF USING  THERMAL FLUID

Water and steam are typically used as heat carriers in heating systems. But at high temperatures, water and steam requires a corresponding high operating pressure. In industrial heating systems a high temperature level is often a great advantage, and establishing this with water and steam can be very controversial and expensive - both in terms of personal safety, economy, design and projecting issues. Read more about these issues here.

In thermal fluid heaters, a special oil is used instead of steam/water as the heat carrier. It is quite simple to achieve operating temperatures up to 300°C at atmospheric pressure. Comparing to water and steam, it would require a pressure of 85 bar to obtain this temperature.

There are several advantages by using thermal oil compare to e.g. steam systems. The most obvious are:

	High temperatures up to 300°C at atmospheric pressure
	Optional temperature level set-points
	No equipment for pre-treatment of boiler feed water
	No heat loss due to hot condensate and flash steam
	No risk of corrosion and no risk of freezing damages.
	Low maintenance costs
	Quiet in operation (no steam stroke and flash steam noise)
	Easy to operate (does not require steam boiler certified staff)

Why thermal fluid instead of steam ? Read more about this important issue.

 

EXTENT OF DELIVERY

The VTO thermal fluid heaters can be delivered in horizontal design (with low height), or in vertical design (occupying limited floor space).

See the sketches below.

The heater units are delivered thermal insulated and with heat shields. The enclosure is stainless steel cover sheets. The unit design includes burner (or electrical elements), armatures, instrumentation, safeties and control panel - and with full documentation including necessary certificates.

Accessories can be chosen in order to complete the thermal oil heating system. Many of these accessories can be build on a complete skid-mounted unit  - or the can be build into a container.

Beside the containerized system, that comprise mainly the heater itself, together with most of the main components, AB&CO · TT BOILERS also deliver complete thermal fluid heating systems (read more about the system solutions in column on the left).

 

SPECIAL DESIGNS

Beside the standard execution, the VTO heaters can be delivered in e.g. following variations:

	Electrical heated and EX-design (ATEX)
	Flue gas heated
	Steam heated
	Combination of heat sources
	Container solutions
	Skid-mounted units
	Complete heating systems
	Material in stainless steel
	Any customized design

CONSTRUCTION

The oil/gas-fired heaters are made with coils of PED certified steel tubes. The thermal fluid is heated gradually to the operational temperature during the circulation inside these tubes - and the heat is transferred to the oil as radiant heat in the combustion chamber, where the inner cylindrical tube coil and a flat tube coil forms the chamber wall and the bottom respectively. Consequently refractory concrete is avoided. The combustion gasses are hereafter cooled in the outer convection part, as the gasses pass the space gab between the two tube coils. The thermal design ensures a modest volume of the thermal fluid relative to the size of the heater, and allows unlimited thermal expansion due to the high fluid temperature. The heater and the thermal oil heating system in whole are constructed and equipped according DIN 4754. Pressure vessels are made according the European regulations including PED and according to EN norms.

Container Solutions - closed type container
 

Container Solutions - open type container

The electrical heated thermal fluid heaters are build-up as a battery of one or several pressure vessel modules equipped with with conventional or pull-out heating elements.
 

Skid-mounted Unit - Electrical heated

They are generally both calculated and designed as heat exchangers involving for each project individual transfer and flow calculations on the heat surfaces.

All VTO thermal fluid heaters are carefully checked, controlled and function tested prior to dispatch from the workshop.
 

BURNERS & ELECTRIC HEATING ELEMENTS

The oil/ and gas-fired thermal fluid heaters are equipped  with only international recognized and only high quality burner brands - adapted to operation on natural gas, light fuel oil, heavy fuel oil or combinations (dual fuel). Demands for special burner designs can be meet and adapted in the heater design - for instance burners for combustion of bio-gas and other low caloric gasses.

The electrical heated units are delivered in two options. The conventional electrical tube heat exchangers are used typically for low temperatures and the costs for these are correspondingly low. For demanding task, it is recommended to use full welded steel tube, where the inner heating wires place in ceramic elements can be pulled out, without emptying the heater for oil.

The engineers at AB&CO · TT BOILERS calculate the optimum heat load in the heater individually i.e. for each task, - ensuring that the film temperature of the thermal oil is never exceeded  even during stop and start.

 

Skid-mounted Unit - Gas-fired

EXHAUST GAS COOLERS - ECONOMIZERS

When it it not possible to use electrical heating using electricity from wind power, nuclear power or water power, - the environmental challenge is to reduce the fuel consumption in the oil and gas-fired solutions.

Here the a low flue flue gas temperatures  are the key words, - the heat recovery is thus done by utilization of  the quite large amount flue gas heat in exhaust gas coolers also known as  economizers. AB&CO · TT BOILERS offers the complete systems of high efficiencies and very low pay-back times.
 

Economizers can be delivered build-on the oil or gas-fired heater, for heating external colder fluid e.g. water - or the thermal fluid heater is made as a heat exchanger for an external heat source of hot flue gas.
 

CO₂-REDUCTION, HEAT RECOVERY
- AND OTHER ENVIRONMENTAL ISSUES

Heat recovery and environmental considerations have always been a standard issue - long before these became a official worldwide protocol. A lot of money is available by thinking "green". For that reason AB&CO offers a consultant service that has become very popular among hard-core company economists. See more about this at AB&CO · CONSULT.

THE THERMAL FLUID

The circulating heat transfer fluid, also known as the thermal fluid (or thermal oil) needs to be correct chosen. Compromise on this issue can easily result in huge problems - but economical and with respect to ensure personal safety. It cannot be emphasized strong enough how fatal bad, old and and inappropriate thermal oil can be for the thermal fluid heating system.

Use a quality brand of thermal fluid and make sure that the thermal fluid correspond how the heating system is operated.

Every 6 - 12 months, a sample should be taken from the system and send to a qualified laboratory (make sure that they know about thermal fluid systems and what traces they should look for in the sample).

Due to this important issue, AB&CO has established a department dealing with thermal fluid supply and sample analysis:

It is recommended to use a non fouling, high temperature resistant thermal fluid for the applications like AB&CO NF. This fluid is available at our stock in Copenhagen.

THERMAL FLUID SYSTEM SOLUTIONS

A correct and safe system design is very important for high temperature systems. This can be ensured by using AB&CO · TT BOILERS as system supplier of the whole system. The engineers of AB&CO · TT BOILERS will design the heating system in a close dialog with the customer and/or the contractors. Visit on site can be provided for the kick-off meeting, commissioning and start-up.

AB&CO · TT BOILERS has 20 years experience with thermal oil heating (hot oil) solutions world-wide - both new installations or modified systems.

Complete hot oil heating systems with heaters, heat exchangers, tanks, pumps, armatures, instrumentations and piping can be delivered as package solutions and as skid-mounted units - individually designed according DIN4754.

Type VTO

[kW]

Heat
Capacity
[Mcal/h]

A

[mm]

B

[mm]

C

[mm]

D

[mm]

E

[mm]

F

[mm]

Weight
Empty
[kg]

Weight
Service
[kg]

On request