Heater hire companies (that also offer dehumidification machine hire) are increasingly assisting the UK’s industrial high pressure water jetting Painting or Shot blasting companies tasked with cleaning and then drying out large storage tanks and vessels belonging to (amongst others):

● Petrochemical companies and refineries (such as Shell Oil, BP);

● Chemical plants (such as Ineos Chlor, ICI, GrowHow, Tata); and

● Grain storage companies (such as Spillers, Tate & Lyle, British Salt, British Sugar).

Other industries with this requirement include: Power, Utilities, Beverage & Distilleries, Cargo and Water Treatment.

Cleaning and drying are vital processes. For example, for grain storage companies, moisture left in their tanks can mean that their product(s) will perish and become un-saleable.

What a heater and dehumidifier hire specialist will do

Generally, companies will contract out their tank cleaning requirements to a proven specialised industrial company. Once the cleaning is done; the services of a heater and dehumidifier rental specialist will be called upon to handle the tank drying process.

The specialist could also play a role in the maintenance of the tanks (this can occur at any time of year – the processes are not "weather dependant’). For instance, a tank may be showing signs of deterioration inside, or its internal coatings are at the end of their working life. The tank needs to be emptied, shot blasted and repainted, therefore. Heating and dehumidification equipment will be used to assist in keeping the shot blast moisture free during the process, and also in maintaining temperatures inside the tank during repainting and paint curing.

Rentable heaters and dehumidifiers may also be used for drying out purposes during tank installation, commissioning and prior to their employment. For example, a heater and dehumidifier leasing specialist could be asked to provide a scheme for maintaining humidity and temperature levels during a critical period when coatings are being applied to newly-built concrete tanks at a water treatment plant.

How the units are combined

Rented heaters and dehumidifiers are not used separately during the drying process, but in a combined way. Reduced humidity air from a dehumidifier is delivered into the intake of an in-direct fired* or electrical heater, fed through the heating system, and then (via ducting), into the access point of the empty storage tank (via ducting).

• Indirect-fired heaters are sophisticated and reliable heaters most suitable for places with limited ventilation; they will deliver huge volumes of clean, dry, fume-free heat safely and economically. They can also deliver warm air via ducting (up to 40m).

Models used

Generally a desiccant dehumidifier would be used in these applications. These type of units use moisture-absorbing materials like silica gel and are employed when very low relative humidity is needed, work is being carried out at extremely low temperatures, a low dew point is essential, or for when the unit has to be ducted into the area that needs drying. Desiccant materials have a high affinity for adsorbing water vapour – up to 10,000 m3/hr, in fact.

A cost-effective option

The main problems petrochemical companies, chemical plants, and food and beverage firms, etc. face when it comes to looking after their tanks each year is in maintaining:

Tank integrity;

Temperatures required for adhesion and curing of coatings; and

Low relative humidity (to preserve tank interiors) during periods when they are not in use

Effective drying after cleaning

Expert industrial drying is the solution to these problems, prolonging the life of tanks and vessels (meaning owners can avoid the huge cost involved in paying for replacements). Hiring in the required equipment is both an attractive and cost-efficient option as units are only on site when in use, there is no capital outlay to purchase them and a hire specialist will ensure that the client is supplied with the most effective solution for each individual case.