Oils systems heating

The need to keep these two aspects separated is best illustrated by a situation where the same product is to be made at different plants. While it is possible that the processing equipment at the two plants is identical, this is rarely the case. Suppose one plant uses steam for heating its vessels, but the other uses a hot oil system as the source of heat. When a product recipe requires that material is to be heated to a specified temperature, each plant can accomplish this objective, but will go about it in quite different ways. 

A typical lubrication oil system is shown in Figure 15-1. Oil is stored in a reservoir to feed the pumps and is then cooled, filtered, distributed to the end users, and returned to the reservoir. The reservoir can be heated for startup purposes and is provided with local temperature indication, a high-tempera-ture alarm and high/low level alarm in the control room, a sight glass, and a controlled dry nitrogen purge blanket to minimize moisture intake. 

Adequate facilities must be provided for draining water from heat transfer and other hot oil systems. 

Both gas and oil-fired heating systems consist of several subsystems. The oil burner pump draws fuel... 

Where high operating temperatures are required, high-temperature thermal fluid systems may be used instead of pressurized water or steam systems. These systems operate at atmospheric pressure using non-toxic media such as petroleum oil for temperatures up to 300°C or synthetic chemical mixtures where temperatures in excess of this are required (up to 400°C). Some advantages and disadvantages of thermal fluid or heat transfer oil systems are listed below. 

Using a hot oil system for heat transfer, the maximum temperature rise observed within the reactor at 98-99 % HBr conversion was only about 13 °C at a reactor... 

Acrylic Elastomers. Acrylic elastomers possess good oil and heat resistance. They are made by polymerizing monomeric acid esters of ethyl or butyl acrylate and methoxyethyl acrylate or ethoxyethyl acrylate. They can be polymerized in emulsion, suspension, or solution systems (9) (see... 

Various glycol regeneration methods were considered, such as direct-fired glycol reboilers, o direct-fired indirect hot oil system, electricol heating ond waste heat recovery. A direct-fired in-direct hot oil system was finally selectd because it provided a safe, well proven regeneration system which could be accommodated within the platform space limitations. 

The Seveso accident in 1976 also involved the glycol-based process, but differed fundamentally from the 1968 incident. While the latter apparently involved a thermal runaway initiated during the hydrolysis reaction by application of excessive heat by the faulty hot oil system [7], the process design adopted by Icmesa at Seveso featured heating the reaction vessel by steam at 12 bar (192°C if saturated) to ensure a minimum 40°C safety margin below the known decomposition temperature of 230°C [5]. At Seveso the exothermic hydrolysis reaction had been completed, but... 

Incorporating an air heater (to utilise low-level heat) on a steam boiler can be more economic than using a hot-oil system which is designed for high-level heat only. 

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