RU2633499C2 - Method of conelets drying - Google Patents

Abstract

FIELD: wood processing industry.

SUBSTANCE: method includes conelets placing on horizontal shelves in shelves of the drying cabinet with a perforated bottom, the providing the heat carrier to the drying zone, and removing the moist air outside the cabinet. In this case, tubular heat exchangers for the coolant fluid are used as shelves of the cabinet, an electric or gas water heating boiler with automatic control of the coolant temperature is used as the heat source, and the coolant is supplied to the drying zone by means of a circulating pump.

EFFECT: method provides more uniform conelets drying, increases productivity and significantly increases the efficiency of the conelets drying process.

3 cl, 1 dwg

Description

The invention relates to forestry, and in particular to methods of drying conifers with the aim of extracting seeds from them.

The seeds in the cones are under the flakes that tightly cover them. To extract seeds, you need to open these flakes. Scales of cones open when humidity decreases in them, for example, in the spring under the sun.

The acceleration of reducing moisture cones is achieved during heat treatment in special installations for drying cones.

The most common is drying cones by blowing warm air. Pine cones are processed at a temperature of 50 ° С ... 55 ° С, cones were eaten at a temperature of 45 ° С, and larch cones at 40 ° С ... 45 ° С. The drying time depends on the initial humidity and temperature, the type of drying device and lasts from 10 to 40 hours.

A known method of drying conifers in two stages: pre-drying and drying, while pre-drying is carried out at a temperature of 100 ° C ... 160 ° C and a pressure of 80 ... 100 mm Hg until the cones open, and dry at a temperature of 50 ° C ... 80 ° C and the same pressure (see AC No. 153691).

However, high temperature and humidity during pre-drying negatively affects the condition of the seeds, and the drying process has a high energy intensity.

Also known is a method of heat treatment of cones to obtain coniferous seeds, in which drying is carried out in three stages in fixed layers when the coolant is supplied under a pressure of at least 60 kg / sq.m and a temperature on the first floor not exceeding 20 ° C, on the second - 40 ° C, on the third - 60 ° C, and the transition time from one floor to another is controlled by humidity (see AC No. 440924, F26B 3/06).

This method in essence and the achieved effect is closest to the proposed method and adopted as its prototype.

However, the large areas of the shelves of shelving for cones and a sufficiently large thickness of its layer require uniform distribution of the air flow over the area and its large initial speed, which requires large expenditures of energy for communicating speed and blowing heated air through the processed layers of cones.

The objective of the present invention is to ensure uniform drying and reduction of energy consumption, increasing the productivity and efficiency of the drying process of cones.

The problem in the proposed method for drying cones of coniferous species, including placing cones on the horizontal shelves of the drying cabinet in boxes with a perforated bottom, supplying heat carrier to the drying zone and removing moisture outside the cabinet, is solved by using tubular heat exchangers for liquid coolant, and an electric or gas water boiler with automatic control of the coolant temperature is used as a heat source, while the coolant is supplied to the drying zone produced by the circulation pump. Moreover, water is used as a liquid coolant, and an additional heat source is a water boiler using empty cones freed from seeds as fuel.

In addition, the warm and moist air removed from the drying zone is used to heat and pre-dry the next portions of cones.

The method can be carried out in drying cabinets by placing cones in boxes with a perforated bottom on shelves one above the other. In more detail, the technical solution is illustrated by the drawing, which shows a diagram of the drying of cones according to the proposed method.

The cabinet for final drying consists of a heat-insulated casing 1 with doors 2, shelves 3 for drying boxes 4 with a perforated bottom, an electric or gas water boiler 5 with automatic temperature control and a circulation pump 6. Shelves 3 of the cabinet, made in the form of tubular heat exchangers, in series interconnected by a water heating boiler 5 and a circulation pump 6 form a single closed loop.

It is advisable to provide the dryer with an additional solid fuel boiler 7. As solid fuel, it is advisable to use empty cones freed from seeds. Exhaust fan 8 is used to remove moisture.

Boxes with a perforated bottom are filled with wet cones and mounted on heat exchanger shelves 3.

When the circulating pump 6 supplies the water heated in the boiler 5 (heat carrier) to the tube heat exchangers of the shelves 3, the temperature inside the heat-insulated casing is quickly set at the optimum drying temperature, while the whole mass of cones located in the drying boxes with a perforated bottom quickly heats up on all shelves and begins to intensively release moisture. When the exhaust fan 8 is turned on, warm and moist air is removed from the chamber and supplied to the cone drying bin (not shown), and from there still warm air enters the fresh cone storage (not shown) for heating and drying, which contributes to significant energy savings. during final drying, as portions of cones generally undergo a three-stage heat treatment. Electronically controlled water heaters are reliable, operate with high efficiency and are easily adjusted to the optimum temperature. An additional heat source is an additional water heating boiler 7, which uses empty cones freed from seeds as fuel. With this method of drying the cones, there is no need to communicate a high-speed coolant to purge the entire processed mass of cones, there is no need for even distribution of air, tubular heat exchangers distribute heat over the area of the rack or boxes much more uniformly, and most importantly without additional energy costs.

The circulation pump and exhaust fan require significantly less energy to operate.

Thus, a more uniform drying of the cones on the shelves, a decrease in energy intensity, an increase in the productivity and efficiency of the drying process of the cones are achieved.

Claims (3)

1. The method of drying cones of coniferous species, including placing cones on the horizontal shelves of the drying cabinet in boxes with a perforated bottom, supplying heat carrier to the drying zone and removing moisture outside the cabinet, characterized in that tubular heat exchangers for liquid heat carrier are used as shelves of the cabinet, and an electric or gas water boiler with automatic control of the temperature of the coolant is used as a heat source, while the coolant is supplied to the drying zone by circulation ground pump. 2. The method of drying cones according to claim 1, characterized in that the additional heat source is a water boiler using empty cones freed from seeds as fuel. 3. The method of drying cones according to one of paragraphs. 1, 2, characterized in that the warm and moist air removed from the drying zone is used to heat and dry the following portions of fresh cones.

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