1. Desiccant Dryers

Wherever compressed air with a pressure dew point below 0C is required , treatment using a refrigeration dryer is no longer feasible from this point on adsorption dryers must be employed.

Heatless or heat regenerating desiccant dryers provide pressure dew points down to -70 C and are used to treat air for applications requiring exceptionally dry air , such as those in the electronics , food and beverage industries . NOAVAR desiccant dryers ensure exceptional efficiency and reliability

1.1 Heat regeneration

Compressed air dried to dew points as low as -40 C is often needed as process air , for frost –prone areas or in sensitive industries such high degrees of moisture removal are achieved by NOAVAR desiccant dryers the use of heat regeneration ensures that very little compressed air is needed for purging the desiccant is regenerated with externally heated blown air ( photo )

Advantages

- Particularly low energy demand thanks to efficient thermal insulation and very low purge air demand.

- Generous volume of desiccant charge for secure drying .

- Less floor space .

- High energy saving

- Long life , low operational costs.

- Great reliability

- Easy maintenance .

- 15 months guaranty and 10 years after soling.

1.2 Heatless Desiccant Dryers :

These dryers use a small proportion of the processed compressed air to reactivate the wet desiccant bed . Although many manufacturers claim to be more efficient than their competitors , no desiccant dryer manufacturer actually makes any desiccant , it is far too complex and expensive . The result is that they all tend to buy the products from the same source .

A heatless dryer will need between 15-18% of the dryed air to be used for reactivation purposes .

This is commonly called purge air.

If you say it quickly 15-18% does not sound much .But it is very expensive .Having gone to the trouble of compressing the air , filtering the air and drying the air , almost 1/5th is blown back through the wet tower on a continual basis to regenerate the desiccant.

The principle of heatless regeneration is simple .When you expand compressed air from 7 barge to atmospheric pressure , the moisture content inside the air remains the same in real terms. For example , if it contained 1 gram me at pressure , it still contains 1 gram me once expanded.

However , the relative humidity of the air will change dramatically . Instead of 1 cu meter of compressed air containing 1 gram me , we now have 7 cu meters of expanded air containing 1 gram me . The air has become much drier .



By venting 15-18% of the processed compressed air back through the wet tower at atmospheric pressure,

The air is significantly much drier than the desiccant bed it is passing over . The molecules of water vapor jump out of the wet desiccant into the dry air , thereby reactivating the bed .



One advantage of heatless dryers is that they can be pneumatically controlled , this allows them to be installed into hazardous areas.