required cooling technology products
Required cooling technology products are usually made forcibly blowing air supplied to the special supply plant with a mandatory cleaning from dust. Most of the air cooled artificially in the warm season, for the treatment of air conditioners installed special technology.
Table. 30 shows some data on the ventilation process. Listed in the table numbers - average and in some cases must be qualified by calculation.
Table 30. The amount of air supplied for cooling products
Based on empirical evidence say that the cooling of 1 kg of biscuits required 1,2-1,5 m3 of air at a temperature of + 18 В° C. For the caramel airflow reaches 6.8 m 3 per 1 kg of product.
As seen from Table. 30, the temperature of the cooling air in all cases lower than the outside temperature in summer.
However, in small factories usually do without artificial cooling air blowing.
Cooling air enters the production room and affects its thermal balance. Continuous operation of cooling systems coming from their air must be taken into account and the balance in the air space. Depending on the final temperature of incoming air in the room or make the extra heat (and sometimes moisture), or a room cooled. In most cases, air enters with a temperature below room temperature (except for summer when there is no artificial cooling).
In determining the amount of heat released by cooling products, heat confectionery receive an average of 0.4 kcal / kg вЂў deg.
The volume of air supplied to cool the products are sometimes calculated on the amount lost by the heat and the temperature gradient between the feed and exhaust air. The practice of operating systems shows that the open blowing air heated by 2-6 В° C depending on the intensity of the blowing and the initial temperature of the product. For normal conditions can be approximately given by the following values of the temperature difference (В° C):
These figures - average and must be specified in each case. Generally, this issue needs to be clarified on the basis of well-posed practical observations. At the present time, more precise data are not available.
In areas without significant emissions of certain harmful substances, mostly without heat and vlagovydeleny, to determine the airflow calculation is difficult. In the back rooms of air when general ventilation is appointed by the multiplicity of exchange. For areas of the normal height of 4-5 m under normal production process are advised to take the multiplicity of exchanges per hour:
Reception and preparation of cranberry .... 5
Department of packing ....... 4-6
receiving milk ........... 3
storage of finished products ...... 1-2
treacle station ......... 4-5
workshop production of halva ....... 5-7
Expedition ............ 1-2
cutting sweets and chocolates вЂў 4-5
raw materials warehouse ........... 1-2
Need to avenge that recommended above, the multiplicity of exchange regulated by the technological design of the confectionery industry. Practice has shown that the air exchange, designated on the basis of the mentioned regulations are insufficient, especially in summer when the windows do not open.
Isolation of toxic gases and vapors in the confectionary production is observed, with a few exceptions. Small amount of sulfur dioxide released in the department of preparation of raw materials; indoor refrigeration inadvertent breaches of ammonia.
Some practical guidelines for determining the volume of air removed by local suction devices are listed in Table. 31.