DRYING OF BREWER’S GRAIN

 

The drying of brewer's grains usually does not present any technical or technological problem. The properties of material are known and stable; it can be perfectly dried in different dryers.

There is a particular issue relating to addition of residual brewer's yeast to brewer's grains that are being dried. Such addition can increase the level of protein in the finished product, meaning it can improve the quality and increase the cost of the finished product – dried brewer's grains. However, residual brewer's yeast has a comparatively high level of relative humidity (usually exceeding 85%) and contains a large amount of living yeast cells. That's why we are forced to reconsider the heat balance of the dryer towards higher heat consumption and to take special measures for thermolysis of residual brewer's yeast.

However, the main problem of breweries relating to the issue of drying of brewer's grains is a strongly pronounced seasonality of production (and sales) of beer and the related amounts of the resulting brewer's grains to be dried. The experience of Ukrainian brewers shows that the amount of brewer's grains which is accumulated during the production of beer in the period from December to February, is 2-2.5 times less than that in the period from June to August. It results in different capacity of section of drying of brewer's grains during the "low" and "high" brewing seasons.

The ordinary way to solve this problem is to implement the drying section consisting of two identical processing lines where one line or both lines are in operation depending on the current needs of the plant.

The main disadvantage of classical solution lies in excessive investment expenditures (for two processing lines) and low specific performance during the transitional periods of operation, when both lines are part-loaded.

LLC "TKS Service" found the original solution to the problem of optimal drying of brewer's grains using one device under the circumstances of multiple changes of the required capacity.

The essence of our proposal lies in the specific application of conventional dryers of our own make - SKSTP - powered by two simultaneous heat sources:

  • steam with preset parameters (8 bar, 170 °C);
  • specific heat agent generated by mixing heat generator running on gas (products of combustion of natural gas diluted to the temperature of 180-190 °C).

Such solution implies that the amount of drying agent circulating in the system shall remain practically unchanged; its temperature and relative humidity are the only parameters that change, which means that the amount of heat introduced into the unit changes as well. Thus:

  • during the cold season, when the minimum performance is required, the device can run on gas or steam (at the option of the power engineer of the plant);
  • during the warm season, when the performance is at its maximum, the device can run both on steam and on gas at the same time;
  • intermediate modes provide for the possibility of smooth automatic adjustment of the loading level of the unit depending on the required capacity.

The specific performance of the processing line based on such device is improved with increase of its performance which, generally speaking, is characteristic of these circumstances.

Such engineering solution is not a experimental development; it has been designed on the basis of standard, officially accepted and commercially available products that may be subject to minor upgrading depending on particular circumstances (product feeding and product extraction units, as well as control and automation systems are subject to upgrading).

We would like to particularly note that this solution has several important advantages over the classical solution to the problem of drying of brewer's grains, such as:

    • it allows using a single processing unit with optimal energy parameters in the desired capacity range;
    • it allows to reduce the bottom-line price of processing equipment and auxiliary equipment by 25-40%;
    • it allows to increase the reliability of the whole complex due to reduction of the amount of equipment; it allows to reduce the maintenance and repair cost;
    • it allows to reduce the required building area;
    • it allows to improve specific performance of the unit, especially in terms of electric energy consumption (reduction by 30-35%);
    • it makes it possible to adjust the load of the steam boilers of the plant during the cold season, effectively increasing their efficiency.

We can develop, design and manufacture custom units that are designed with due account for special conditions of the customer (specified performance, available premises and equipment of the customer, specified type of heat agent, required level of automation, etc.).

Exemplary specifications of the drying line designed on the basis of the dryer SKSGP operating in the so-called "steam-gas" mode along with a structural diagram of a standard line are presented here.

Last modified on Friday, 25 October 2013 10:22