RU99601U1 - DRYING UNIT FOR CUTTING SAWING MATERIAL - Google Patents

Abstract

 1. A drying installation for edged sawn timber, comprising a sealed enclosure, a drying chamber, at least one means for heating the drying chamber, a condensation system made in the form of condensate pipes located in the upper part of the drying chamber and connected to a water tank, and means measuring temperature and humidity, characterized in that the casing is made in the form of a vertical parallelepiped having a lid in the upper end part for the top loading of lumber into the drying chamber, between the casing and drying An insulating layer is located around the entire perimeter of the chamber, the drying chamber has a vertical design and consists of a chamber directly located above the furnace ducts, and a vertical circulation channel located close to the chamber, while the chamber and the circulation channel are connected by upper and lower openings, and the chamber floor has supports for vertical laying of rows of lumber “on the edge”, the heating means is located under the body and is made in the form of a furnace, consisting of at least a firebox , two chimney flues and at least one exhaust pipe, in addition, the installation includes a humidification system consisting of pipes with holes at the top, located across the chamber in its lower part and interconnected by a central pipe brought out of the housing connected to water and air ducts, and a system of clamping lumber in the stack to prevent hanging lumber in the stack. ! 2. The dryer according to claim 1, characterized in that the casing is made of metal. ! 3. The dryer according to claim 1, characterized

Description

The utility model relates to the forestry and woodworking industries, in particular to drying equipment for drying lumber.

Known drying complex (patent RU 2153640 C1 F26B 9/06, F26B 3/04, publ. 07/27/2000) containing a thermally insulated drying chamber having a free inner space, a furnace located near the drying chamber, means for supplying a drying agent from the furnace to the drying the camera. The bottom of the drying chamber is made with two horizontally located and hermetically separated cavities, an adjacent partition between which is made of heat-conducting material. The lower cavity of the bottom of the drying chamber is configured to force flue gases into it from the exhaust pipe of a hog furnace. The upper cavity of the bottom of the drying chamber is configured to supply air heated in the hog of the furnace, which is a drying agent, which is distributed in the upper cavity of the bottom of the drying chamber through the withdrawal channels for interaction with the dried material, placed in the free interior of the drying chamber at the places provided for this . It is possible to force-supply part of the air cooled and moistened during drying from the top of the drying chamber to the furnace burs. The complex is also equipped with a condensate cleaning unit located outside the drying chamber with the possibility of forcing furnace flue gases into it after passing through the lower cavity of the bottom of the drying chamber, as well as part of the air cooled and moistened during drying from the upper part of the free interior of the drying chamber for them mixing with the formation of condensate and subsequent exhaust of purified air.

The means for forced supply of flue gases from the exhaust pipe of the hog furnace to the lower cavity of the bottom of the drying chamber and to the condensate cleaning unit after passing through this lower cavity is made in the form of a first exhaust fan located outside the drying chamber and the condensate cleaning unit and connected to the outlet of the lower the cavity of the bottom of the drying chamber and the inlet of the condensate cleaning unit. The means for supplying part of the cooled and humidified air from the upper part of the free internal space of the drying chamber to the condensate cleaning unit is made in the form of a second exhaust fan located outside the drying chamber and this unit and connected to them. The means for forced selection of part of the cooled and humidified air from the upper part of the free internal space of the drying chamber and its supply to the furnace burs is made in the form of a third exhaust fan connected to them with the possibility of providing a closed cycle of air circulation from the upper part of the free internal space of the drying chamber to the burs furnace, and air from the pine forest - into the upper cavity of the bottom of the drying chamber, and then into its free internal space. A drain pipe is connected to the casing of the third exhaust fan to discharge into the atmosphere the moisture accumulated in this casing, formed as a result of condensation of the cooled and moistened air taken by the third exhaust fan from the upper part of the free interior of the drying chamber. A shutter is provided in the outlet pipe to adjust the required humidity mode of drying. A pipe is placed in the furnace hog, in which air is heated from the furnace flue gases and circulates into the drying chamber and back, providing the drying process. The specified pipe is made repeatedly bent to increase the path and time of passage of air in the hog of the furnace. In the channel intended for supplying hot air from the hog to the upper cavity of the bottom of the drying chamber, a damper is installed to adjust the required preset temperature mode of the drying process. The lower cavity of the bottom of the drying chamber is provided with at least two partitions to ensure the labyrinth passage of flue gases in the lower cavity of the bottom of the drying chamber. The distribution channels are located perpendicular to the direction of the flow of heated air entering the upper cavity of the bottom of the drying chamber between places provided for and along the material to be dried, each of the distribution channels is separated from an adjacent space for placing the material to be dried by a vertical partition. Places for placement of the dried material are placed on or above the upper surface of the partition of heat-conducting material separating the lower and upper cavities of the bottom of the drying chamber, with the possibility of ensuring the passage of heated air through the dried material when it rises to the upper part of the free inner space of the drying chamber, the dried material has vertical partitions for directing and distributing heated air from the inlet of the upper bottom cavity drying chamber through the draw channels. The possibility of heated air entering the material to be dried is provided after it passes through the draw channels through the free space of the upper cavity of the bottom of the drying chamber, which limits the space for placing the material to be dried along their length. There is an additional possibility for heated air to enter the material to be dried through the through holes in the vertical partitions that separate the places for placing the material to be dried from the draw channels. These through holes are made with different diameters, the magnitude of which increases along the path of heated air through the pipe channel. These through holes are provided with flaps. Through holes are made in the upper surface of the upper cavity of the bottom of the drying chamber near one of its side walls to provide additional intake of heated air from the upper cavity of the bottom of the drying chamber into its free inner space. In the case of drying piles of wood lumber, they are placed in the drying chamber along the draw channels so that their ends are opposite the said through holes. In case of incomplete loading of the drying chamber, it is possible to block the corresponding draw-off channel adjacent to the place for placement of the dried material in which it is absent. The condensate cleaning unit is made in the form of a hollow tank with the possibility of condensate precipitation on its inner walls while mixing cooled and humidified air from the upper part of the free interior of the drying chamber and flue gases from the lower cavity of the bottom of the drying chamber. The power value of the third exhaust fan is greater than the power value of the second exhaust fan.

However, this complex has the following disadvantages:

- the complexity of the design of the drying complex;

- uneven drying, both in different parts of the stack and along the length of the board, since the design of the drying chamber provides for the horizontal placement of lumber in the stack, which makes it difficult for the drying agent to pass through the stack and increases heat loads on individual sections of the board;

- unevenness and poor quality of drying due to the use of fans and the inability to ensure the same flow of hot air throughout the lower part of the chamber (heated air enters the chamber through the holes in the lower part of the chamber and rises upward, diverging along the stack, and the adjacent section does not receive heat);

- heat energy losses, since lumber is located in separate areas (in specially provided places), that is, not all useful volume of the drying chamber is used.

A device for drying lumber (patent RU 2280827 C2 F26B 3/04, publ. 07/27/2006) containing at least one drying chamber, nodes supplying coolant into the chamber and removing exhaust air from it is known. In the side wall of the drying chamber, parallel to the location of the rails in it and adjacent to the batching shop, there are doors for loading and unloading lumber with at least one intermediate door between them. The nodes for supplying the coolant to the chamber and removing exhaust air from it include a heater, equipped with air return ducts with shutters located in the partition between the drying chamber and the heater, and a ventilation system consisting of hatches with shutters in the enclosure of the heater and ventilation wells with shutters in the chamber, air ducts located along the chamber floor along the entire length of the chamber, with slit-like gaps made along the length of the ducts, with the possibility of their overlapping. In the ducts, additionally made connectors in cross section, with the possibility of their overlap.

The disadvantages of the known device for drying lumber are:

- cumbersome design and increased energy intensity of the drying process;

- uneven drying of wood, since the use of fans does not provide the same effect of a drying agent along the length of the board. In addition, the accelerated passage of the drying agent through the stack initiates excessive drying of the outer layers of wood, the occurrence of internal stresses and, as a result, cracking and warping;

- the vertical arrangement of the stack in the chamber really speeds up the drying process of lumber, but the device does not have a humidification system, and excessive exposure to the drying agent without adequate moisture accelerates the drying of the outer layers, which leads to a decrease in the quality of wood.

The closest technical solution, selected as a prototype, is a dryer for lumber (patent RU 2277682 C2 F26B 5/04, F26B 3/02, F26B 9/06, publ. 06/10/2006), comprising a housing forming a drying chamber for loading lumber a vacuum pump for creating a vacuum in the drying chamber, means for heating the drying chamber, condensation means for condensing steam and means for draining the condensate into condensate collectors. The condensation means is made in the form of condensate tubes placed in the upper part of the drying chamber along its entire length. Under the condensate pipes, there is a means for condensate drainage, including a tray and a collector for collecting and removing condensate. The heating means is made in the form of heating pipes, which are located in the lower part on the inner surface of the drying chamber. Heating pipes located in the lower part on the inner surface of the drying chamber occupy two thirds of this surface.

The housing of the drying chamber is preferably cylindrical.

The dryer includes humidity measuring means made in the form of a sensor and installed inside the drying chamber, and temperature control means made in the form of a temperature measuring sensor and installed inside the drying chamber.

The means for heating the drying chamber is an electric boiler.

Outside the end wall of the housing of the drying chamber is a working compartment for placing fixed assets and a control panel and monitoring the operation of the dryer. Fixed assets include a vacuum pump, an electric boiler with an emergency protection system, a membrane expansion tank, a vacuum gauge for measuring vacuum in the drying chamber, a circulation pump for forced passage of water in the heating pipes, and condensate collectors. The control panel includes a display for determining the readings of the temperature control sensor and the humidity sensor inside the drying chamber and the temperature sensor inside the electric boiler.

The heating pipes can be combined in the lower part of the drying chamber into one return pipe, which is brought into the working compartment.

Condensate collectors have inspection windows, condensate drain valves and an equalizing valve.

However, the known dryer for lumber has the following disadvantages:

- the complexity of the design of the dryer, contributing to an increase in its cost;

- high energy intensity of the drying process, the reasons for which are electric heating of the drying chamber, the heating means of which is an electric boiler, and the possibility of using only mild drying modes, since drying is carried out at low temperatures;

- the duration of the drying process and, accordingly, an increase in labor costs and a decrease in productivity, the cause of which is the limitation of the temperature of the coolant;

- uneven drying and, consequently, a decrease in the quality of lumber due to the horizontal arrangement of lumber in the drying chamber, in which hot air washes only the narrow layers of the board.

The technical task of the proposed utility model is the creation of an installation for drying lumber, ensuring the use of high temperature conditions, uniformity of drying, reduction of energy consumption, drying time, cost of the drying unit and the cost of the drying process.

The technical result is an improvement in the quality of drying of lumber and increase productivity.

To solve the problem and achieve a technical result in a drying installation for edged sawn timber containing a sealed enclosure, a drying chamber, at least one means for heating the drying chamber, a condensation system made in the form of condensate pipes located in the upper part of the drying chamber and connected with a container of water, and a means of measuring temperature and humidity, according to a utility model, the housing is made in the form of a vertical parallelepiped having a lid in the upper end part for the top loading of lumber into the drying chamber, between the casing and the drying chamber, heat-insulating layers are located around the perimeter, the drying chamber has a vertical design and consists of a chamber directly located above the furnace ducts, and a vertical circulation channel located close to the chamber, while the chamber and the circulation channel is interconnected by upper and lower openings, and the chamber floor has supports for vertical laying of rows of lumber “on the edge”, the means for heating is located beneath the housing and is made in the form of a furnace consisting of a furnace of at least two chimney flues and at least one exhaust pipe, in addition, the installation includes a humidification system consisting of pipes with holes at the top located across the chamber, in its lower part, and interconnected by a central pipe brought out of the casing, connected to the water supply and air duct, and a system for clamping lumber in the stack to prevent hanging lumber in the stack.

The casing of the dryer is made of metal.

Means for measuring temperature and humidity are made in the form of a sensor and installed inside the drying chamber.

Between the housing and the drying chamber, along the entire perimeter there is a heat-insulating layer in the form of sand.

The drying chamber is preferably made of brick.

Stands for lumber are preferably made of brick, have upper thermal insulation and are located across the chamber at a distance of 0.5 m from each other. Between the rows of lumber, vertically stacked on supports, install gaskets.

The heating agent is made of ceramic (stove) brick, bound by clay. Smoke ducts are made in the form of parallel channels and are located directly under the drying chamber. The furnace chamber is outside the drying chamber and has a furnace chamber, doors, grate and blower. An exhaust pipe is connected to the chimney flues and removed from above outside the chamber.

The pipes of the humidification system are preferably made of metal. The central pipe of the humidification system, outside the housing, is connected to the water supply and air duct through valves.

The lumber clamping system in the stack consists of clamping screws, bushings and wooden stops.

The essence of the utility model is illustrated in the drawing.

The figure shows a front view (cross section) of a drying installation for edged lumber with a stack of lumber placed in it.

The drying installation for edged lumber contains a vertical sealed metal case 1, inside of which are located: a drying chamber 2, a humidification system 3, a condensation system 4, a clamp system for lumber in the stack 5 and a means for measuring temperature and humidity (not shown in the figure). At least one means for heating the drying chamber 6 is located under the housing.

The sealed metal case 1, which serves for tightness and thermal insulation of the chamber, is made in the form of a vertical parallelepiped, in the upper end part of which there is a removable cover (not visible in the figure). The casing covers the drying chamber 2, the humidification system 3, the condensation system 4, the lumber pressure system in the stack 5, the temperature and humidity measuring means and the furnace ducts 7. The upper lid of the casing serves for loading and unloading the lumber. The vertical execution of the case with the top cover is designed for vertical placement of lumber in the drying chamber.

Between the housing 1 and the drying chamber 2, a heat-insulating layer in the form of sand (not visible in the figure) is located around the entire perimeter, which is necessary to exclude air and heat exchange of the chamber and the environment.

The drying chamber 2 has a vertical design and consists of two parts: directly the chamber located above the gas ducts of the furnace 7, and a vertical circulation channel 8 located close to the chamber. The chamber and the circulation channel are preferably made of brick and are interconnected by upper and lower openings. The chamber floor has stands for lumber (not visible in the figure) located across the chamber at a distance of 0.5 m from each other. Stands are preferably made of brick and have top thermal insulation. Stands are designed for laying lumber on them in stack 9, while lumber 9 is laid “on the edge”, and gaskets 12 are installed between the rows of lumber. Thus, peculiar channels are obtained through which the heated drying agent rises up the chamber, washing wide planks of boards. The circulation channel 8 is designed to organize the circulation of the drying agent inside the chamber. It provides advancement of the cooled drying agent in the chamber from top to bottom. The device of the drying chamber 2 with the top loading of lumber ensures the tightness of the chamber and the direction of flows strictly from bottom to top through the stack 9 and from top to bottom through the circulation channel 8, eliminates the occurrence of other flows, thereby ensuring uniform drying of the lumber along the entire length.

The humidification system 3 consists of metal pipes with holes at the top, located across the drying chamber 2, in its lower part, next to the supports for lumber. The pipes are located at the same level relative to each other and are interconnected by a central pipe brought out of the housing 1. The pipe outlet through one valve is connected to the water supply pipe to supply water to the drying chamber at the stage of moistening the lumber, and through the second valve to the pipe with an open the end - for supplying cold air to the drying chamber at the final stage of drying. The location of the pipes directly in the heating zone provides a quick conversion of water into steam. Humidification system 3 is necessary to maintain the temperature-humidity ratio and to inhibit the temperature in the final stages of drying.

The condensation system 4 consists of pipes located at the top of the drying chamber above the circulation channel. Condensate pipes are welded to the upper part of the metal housing 1 and circularly connected to a container of water (not shown in the figure). The pump ensures constant movement of chilled water (refrigerant) through these pipes. Steam condenses on the surface of the pipes, cools and falls down the chamber along the circulation channel 8.

The clamping system of lumber in the stack 5 consists of clamping screws, bushings and wooden stops. The clamping screw is a threaded cylinder freely rotating in the sleeve, one end of which is located in the chamber and connected to a wooden stop, and the other is brought out of the metal case. The threaded sleeve is welded to a metal body, has a length from the chamber to the body. The wooden emphasis is located vertically in the drying chamber and is oriented relative to the supports for lumber (stacks). Clamping screws are located along the housing wall at a distance of 0.5 m from each other. Minimum - 1 clamp per 1 row of gaskets installed between the rows of lumber, optimally - 3 clamps per row of gaskets: bottom, middle and top. Clamping system 5 is necessary to eliminate the hanging of lumber in the stack, it does not allow warping and planking during drying.

Means for measuring temperature and humidity are made in the form of a sensor installed inside the drying chamber.

Means for heating 6 is located under the housing 1 and is a furnace made of ceramic (stove) brick, bound by clay. The furnace 6 also consists of a furnace 10, at least two parallel chimney flues 7 and at least one exhaust (chimney) pipe 11. Smoke flues 7 are made in the form of parallel channels and are located directly under the drying chamber. Smoke flues are necessary for the ability to perform high-temperature drying and heat treatment of wood. They provide uniform heating throughout the drying chamber and a temperature in the chamber of up to 230 ° C. The furnace furnace 10 is moved outside the drying chamber and has a combustion chamber, doors, grate and blower (not visible in the figure). The exhaust pipe 11 is connected to the flue gas ducts 7, removed from above outside the chamber and is designed to exhaust the exhaust flue gases.

A drying installation for edged lumber works as follows.

Lumber 9 is placed in the drying chamber 2 on special transverse insulated stands (not visible in the figure), placing it vertically “on the edge” in rows, between which the gaskets are installed 12. The distance between the gaskets is 0.5 m. After laying the last row, stack 9 they are pressed with clamping screws of the clamping system 5 to prevent lumber hanging in the stack. Hermetically close the lid (not shown in the figure). Then melt the oven. To ignite the furnace, you can use wood waste. The combustion products through the chimneys 7 under the influence of traction rush into the exhaust pipe 11, heating, at the same time, the top of the chimneys 7, which are the floor of the drying chamber 2. When heated, the bricks begin to transfer heat to the drying chamber 2, and evenly on the entire surface of the chamber floor . Since heated air is lighter than cold, therefore, it rises up along the channels formed between the rows of boards with the help of gaskets 12. Hot humid air is lighter than hot dry air, therefore, in contact with the boards and taking away moisture, hot moist air passes through the stack up the chamber where the pipes of the condensation system 4 are located. By switching on the pump of the condensation system 4 (not shown in the figure), refrigerant — cold running water — is supplied to the condensation pipes. In contact with the surface of the pipes, hot humid air cools down and falls down through the circulation channel 8 down the chamber, where it displaces the lighter heated air, heats itself, etc. Thus, continuous circulation in the chamber.

Heating in the chamber occurs gradually, but for high-quality drying, it is necessary that the wood itself is heated evenly, and moisture is transferred from the wood uniformly throughout the section, otherwise internal stresses, cracking, and deterioration will occur. Therefore, to eliminate excessive moisture return from the outer layers of the wood, it is necessary to ensure a sufficiently high humidity of the drying agent. To do this, by opening the valve in the water supply, water is supplied to the humidification system 3. The water entering the parallel humidification system pipes, which have openings at the top and located next to the lumber stands, is heated because the pipes are heated from the chamber floor and, exiting through the openings, instantly turns into steam, which enters the chamber and moisturizes the wood, helping to accelerate the removal of moisture from it.

The temperature increase in the chamber and the need for water supply are controlled using a psychrometer (not shown in the figure).

The drying process consists in the alternation of heating and humidification processes. Upon reaching the maximum drying temperature, stop heating by extinguishing the fire in the furnace 6. Gradually open the exhaust pipes 11, through the humidification system 3 serves cold air from the air duct. There is a gradual cooling and a gradual release of excess moisture from the chamber. The direction of circulation is no longer in a closed cycle inside the chamber. Fresh air coming from the air duct passes through the stack, cooling and drying it, rises up and leaves the chamber through the exhaust pipes 11.

The process goes to complete cooling of lumber 9.

Depending on the drying mode, upon reaching the lower permissible temperature point, heating can be resumed. In some modes, several such cycles are performed.

If necessary, heat and moisture treatment is performed: they produce heating and water is supplied for moisturizing. This is done to relieve internal stresses in the wood.

Carrying out such a drying scheme provides:

- the speed of the process due to the possibility of using high temperature modes with a heating temperature of up to 130 ° C;

- uniformity of drying, because the thermal effect is the same throughout the chamber, and the drying process occurs at the required humidity, eliminating the drying of the outer layers, providing the necessary moisture conduction over the entire cross section of the material;

- the exclusion of warpage of the boards under the influence of temperatures, since the device of the clamping screws allows you to adjust the clamping boards in the stack outside the chamber;

- the possibility of heat treatment of lumber, as the temperature in the chamber can be increased to 230 ° C;

- absence of heat energy losses, since there are no means of heat delivery to the chamber (pipes).

The presence of pipes of the humidification system allows drying in saturated steam, and the design of the pipes allows you to supply water in equal amounts throughout the chamber. The design of the drying chamber with vertical “on the edge” placement of lumber allows the most efficient use of the useful volume of the chamber.

Since heating is carried out directly from the floor of the chamber (a furnace with parallel flues), this eliminates the need for electricity, ensures uniform heating and high temperature inside the chamber. And the use of high-temperature drying modes will reduce the drying time and, accordingly, the cost of the process.

The proposed drying unit is easy to manufacture and operate, which significantly reduces its cost.

Claims (14)

1. A drying installation for edged sawn timber, comprising a sealed enclosure, a drying chamber, at least one means for heating the drying chamber, a condensation system made in the form of condensate pipes located in the upper part of the drying chamber and connected to a water tank, and means measuring temperature and humidity, characterized in that the casing is made in the form of a vertical parallelepiped having a lid in the upper end part for the top loading of lumber into the drying chamber, between the casing and drying An insulating layer is located around the entire perimeter of the chamber, the drying chamber has a vertical design and consists of a chamber directly located above the furnace ducts, and a vertical circulation channel located close to the chamber, while the chamber and the circulation channel are connected by upper and lower openings, and the chamber floor has supports for vertical laying of rows of lumber “on the edge”, the heating means is located under the body and is made in the form of a furnace, consisting of at least a firebox , two chimney flues and at least one exhaust pipe, in addition, the installation includes a humidification system consisting of pipes with holes at the top, located across the chamber in its lower part and interconnected by a central pipe brought out of the housing connected to water and air ducts, and a system of clamping lumber in the stack to prevent hanging lumber in the stack. 2. The dryer according to claim 1, characterized in that the casing is made of metal. 3. The dryer according to claim 1, characterized in that the means for measuring temperature and humidity is made in the form of a sensor and is installed inside the drying chamber. 4. The dryer according to claim 1, characterized in that between the casing and the drying chamber along the entire perimeter there is a heat-insulating layer in the form of sand. 5. The dryer according to claim 1, characterized in that the drying chamber is preferably made of brick. 6. The dryer according to claim 1, characterized in that the supports for lumber are preferably made of brick, have upper thermal insulation and are located across the chamber at a distance of 0.5 m from each other. 7. A drying unit according to claims 1 and 6, characterized in that gaskets are installed between rows of lumber vertically stacked on supports. 8. The drying apparatus according to claim 1, characterized in that the heating means is made of ceramic (stove) brick, bound by clay. 9. The dryer according to claims 1 and 8, characterized in that the flue gas ducts are made in the form of parallel channels and are located directly under the dryer chamber. 10. The dryer according to claims 1 and 8, characterized in that the furnace furnace is outside the drying chamber and has a combustion chamber, doors, grate and blower. 11. A drying unit according to claims 1 and 8, characterized in that the exhaust pipe is connected to the chimney flues and is carried out from above outside the chamber. 12. The dryer according to claim 1, characterized in that the pipes of the humidification system are preferably made of metal. 13. The dryer according to claim 1, characterized in that the central pipe of the humidification system, brought out of the housing, is connected to the water supply and air duct through valves. 14. The dryer according to claim 1, characterized in that the lumber clamping system in the stack consists of clamping screws, bushings and wooden stops.