US2713346A

US2713346A - Pulpwood soaking device

Info

Publication number: US2713346A
Application number: US311383A
Authority: US
Inventors: Sucksdorff Bjorn
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-09-25
Filing date: 1952-09-25
Publication date: 1955-07-19
Anticipated expiration: 1972-07-19

Description

July 19, 1955 B. SUCKSDORFF 2,713,346

PULPWOOD SOAKING DEVICE Filed Sept. 25, 1952 IN VEN TOR.

U fi tates Paten 2,713,346 PULPWOOD SOAKILJG DEVICE Bjorn Sucksdortf, Kuusankoski, Finland Application September 25, 1952, Serial No. 311,383

11 Claims. (Cl. 134-107) This invention relates to improvements in'pulpwood soaking devices for use in wetting pulpwood effectively prior to barking.

Pulpwood is, in the main, either floated or transported by land to its place of use.

A part of the bark and sapwood might already then have been removed therefrom.

The moisture content thereof varies and depends on the transportation method adapted, age of cut tree and storage facilities.

Prior to using pulpwood it is necessary in most cases to strip all the remaining bark therefrom so as to obtain a pure end-product, a pure chemical pulp, mechanical pulp or paper.

If the pulpwood is moist and especially if same is floated, the bark strips off easily. But should the pulpwood have dried in the woods and is, e. g. half peeled or strip barked, the bark sticks hard to the log.

Previously, cut trees were barked at their place of use by means of knife barkers which stripped from the surface of the tree appreciable amounts of wood besides bark. Thus wood losses were appreciably great but the barked log was very clean. To reduce material losses knife barkers were replaced by means using other barking methods such as e. g., rotating barking drums, chain barkers or hydraulic barkers. All these means and methods have for their object to strip off bark without damaging the wood material. Then too, it is naturally of first-rate importance that the bark sticks as loosely as possible to the cut tree or log.

Should dry wood with dried bark strongly adhering thereto be barked e. g., in barking drums unduly long periods of time are required for the operation partly for the reason that the dark must be soaked in water for so long a time as to give it a moisture content adequately high to enable the bark to loosen readily, partly for the reason that dry bark requires more vigorous mechanical treatment than does moist bark. It follows that machines must be large in size and expensive and that the logs will, in consequence of barking operations of long duration, be subjected for a longer time to high mechanical stresses which in turn cause the ends of logs to wear out round and form brushy splitters with consequent losses in wood substance, increase in necessary power and appreciable wear and tear of the drums.

Practice has shown that the treatment time for wood fed dry into barking drums may even be seven times longer than that for wet or efficiently soaked wood.

However, the soaking of wood is no simple operation, and in different places it might be effected in very many ways.

The simplest way is to keep the wood in large ponds, lakes or water courses. For reducing necessary storage space the wood is stored in bundles. This, however, requires much Work and if it is desired to soak the part floating above water level also, the bundles must be turned or arrangements made for continuously spraying water over the wood or log bundles. The whole treatment 2,713,345 Patented Judy 19, 1955 ice requires much space, is expensive and especially in winter disadvantageous.

Another method of soaking wood comprises the filling of soaking chambers or soaking towers with the wood, which is prevented from floating up when water is being admitted into the said chambers or towers. Also this method is expensive because of its periodicity.

A third method comprises submerging the Wood into water, in a long soaking pond by means of wide, matlike conveyors. However, such devices have not been successful in soaking woods longer than 2 feet, because longer woods in disorder easily jam the soaking channel.

Moreover, there are prior known methods according to which the wood is arranged in parallel bundles, which are placed into short soaking ponds and submerged in water by means of a large rotating drum. The construction of the soaking ponds and towers hereinabove described renders possible the use of warm water therein, but the higher the water temperature rises the greater will be the operation difficulties because of evaporation and mist formation.

It is the object of this invention to provide a pulpwood soaking device without the defects hereinabove described.

An object of the invention is to provide a soaking device through which the pulp wood to be treated is fed as a continous pile in such a way that the shape of the pile is not altered and no relative movement occurs between the logs.

Another object of the invention is to provide a pulp Wood soaking device having means for automatically stopping the feeding of pulp wood into the said soaking device should the wood in the pile become disarranged.

Still another object of the invention is to provide a pulp wood soaking device having means for regulating the temperature of the water and means for efiectively circulating same in countercurrent to the movement of the Wood.

And still another object of the invention is to provide a pulp wood soaking device having means for regulating the speed of feeding the wood as also the amount of wood to be fed through said device.

The foregoing and other objects of this invention will be apparent from the following specification, taken in con nection with the accompanying drawing wherein a preferred embodiment of the invention is shown.

In the drawing:

Fig. 1 is a schematic side elevation of the soaking device made according to this invention.

Fig. 2 is an enlarged, sectional view taken along line A--A of Fig. l, and

Fig. 3 is an enlarged, sectional view taken along line B-B of Fig. 1.

The principal parts of the device shown in the drawing are:

A long water-filled channel 1, open at both ends thereof.

A conveyor 2, hereinafter to be termed supply conveyor adapted to feed wood into the channel as a continous pile.

A conveyor 3, hereinafter to be termed transfer conveyor having a speed approximately equal to that of the first-mentioned conveyor and adapted to press the wood under water and convey the same through the channel.

A conveyor 4, hereinafter to be termed withdrawal conveyor and adapted to lift the soaked wood away from the channel to be transported to subsequent treatments, and

Pumps

11, 15 for circulating the water and heat exchangers 13 for heating the water.

The channel 1 is curved so that the ceiling and bottom parts thereof are shaped to form concentric cylinder parts having very great radii and an axis located above the said channel and at right angle to the longitudinal axis of the channel. At the supply end the bottom of the chan nel is recessed to accommodate the supply conveyor 2 zhich is also curved to form a cylinder part concentric with the channel. The supply conveyor 2 includes a plurality of endless chains arranged side by side and having fixed thereto suitable gripping members. Both ends of the supply conveyor 2 and consequently the whole conveyor, can be raised and lowered at will with lifting means schematically shown by arrows 5.

The transfer conveyor 3 is so arranged that while the forward moving part thereof runs along the ceiling the rearward moving part runs above the channel. The conveyor itself includes a plurality of chains (seven in the drawing) having fixed thereto transversely disposed catchers. These catchers have a threefold function: firstly they sink between the logs and thereby pull the pile forward, secondly they run in grooves 9 made in both upper corners of the channel and thus keep the chains correctly in place also when the channel is empty, and thirdly they give support to the chains on the return side. To prevent the chains from wearing out, they are placed between longitudinal rails 16 in the channel roof allowing the catchers and uppermost logs in the pile to contact the rails. To prevent breaking in the case that too high a pile is fed between the

conveyors

2 and 3, the supply end 6 of the conveyor 3 is mounted turnable on hinges 7.

The supply conveyor 2 and transfer conveyor 3 derive their movements from suitable power sources, e. g., electric motors not shown in the drawing. These two conveyors run with substantially one and the same speed which is proportional to the curvature radii, the two speeds being advantageously adapted to be regulated simultaneously and in the same ratio.

On both sides of the supply opening of the channel I. are arranged bars 8 which, when hit by a log, will cut off the current to the motors of the

conveyors

2 and 3 and thereby cause said conveyors to stop. Thus the channel is prevented from becoming jammed should the logs be sidewise disarranged on arriving at the supply opening of the channel.

At the discharge end of the channel 1 is arranged the withdrawal conveyor 4 comprising a plurality of endless chains with thereto rigidly secured gripping means and adapted to be run by a motor not shown on the drawing at a speed slightly greater than those of the

conveyors

2 and 3. Also the withdrawal conveyor 4 is curved concentrically with the curvatures of the channel 1 and the supply conveyor 2 and the transfer conveyor 3. Underneath the withdrawal conveyor 4 is arranged a suitable conveyor, e. g., a band conveyor for receiving the falling logs.

For circulating water in the channel 1 and for heating same a screen 10 is arranged beneath the supply conveyor 2 to permit passage of water therethrough into a tank 13 wherefrom it is forced by means of the pump 11 via pipe line 1.9, heat exchanger 13 and one or more pipes 14 passed through the channel ceiling into the discharge end of the channel 1. By means of the heat exchanger the water can be heated to the temperature desired. Moreover, two pumps 15 are arranged in the channel to suck water from the side walls or bottom of the channel and then force it via the pipes 20 back into the channel through the ceiling thereof. Thus water circulates in countercurrent to the movement of the wood.

For removing bark and other impurities carried by the water to the screen 10 there is arranged one or more scraping means 12 for cleaning the screen 19 continuously.

The device operates as follows:

Wood is piled manually or by means of a lifting device into an endless pile upon the supply conveyor 2 which continuously feeds the pile forward and downward. As the pile runs into water the downward pressure gradually decreases until the water has risen so high that the whole pile floats. Then the upper part of the pile comes into contact with the transfer conveyor 3 which continues the forward movement while forcing the whole pile under water. Should the shape of the pile change in this phase and the logs in the pile move relative to each other it may happen-especially if the logs are crookedthat they push themselves towards the sidewalls of the channel. Should this happen, the whole channel will soon jam up. According to the invention no changes in the shape of the pile will occur partly because the channel itself, supply conveyor 2 and transfer conveyor 3 are constructed so as to form concentric cylinder parts having very big radii and an axis located above the channel, and partly because the distance between the supply conveyor 2 and the transfer conveyor 3 can be regulated by raising or lowering the conveyor 2 to suit the height of the pile. Moreover, the supply end 6 of the transfer conveyor 3 may turn about the hinges 7. Should a log or two despite everything turn sidewise they would, in so doing, hit the bars 8 which thereby cut off the current and stop the motors, after which it is possible to correct the positions of the logs, c. g. with a boat hook.

At the discharge end of the channel the pile frees itself of the transfer conveyor 3 and the logs move towards the withdrawal conveyor 4 having a speed greater than that of the two previously mentioned conveyors and adapted to lift the logs from the water and over the channel threshhold onto the conveyor 17 adapted to transport the logs onward for further treatment.

It is important that all the logs are wetted and heated evenly. This is achieved in the claimed device wherein water heated to the desired temperature is fed in countercurrent flow to the movement of the logs. Water is pumped from the fore-end of the channel 1 via the heat exchanger 13 and onwards to the rear-end of the channel where it is forced into the channel through a pipe or pipes 14 between the rails 16 in the ceiling. The rails serve as guides and prevent water from flowing sidewise, wherefore water penetrates down through the pile. There the water cools down in consequence of which the downward flow through the pile becomes more effective. Because of the circulation pumps 15 which suck water from the bottom of the channel and force it down from between the rails 16 in manner similar to that hereinabove described, circulation and soaking are as effective as possible. Hence, heating up and wetting occur gradually in the counter-current flow of logs and water.

The period of time for soaking can be varied by running the

conveyors

2 and 3 at varying speeds. The pulp wood amount in the channel can be varied thereby that the height of the pile is increased or decreased by raising or lowering the conveyor 2 and in addition to this soaking efiiciency can be increased or decreased by changing the water temperature. Hence the device is suitable for use in treating different kinds of wood intended for various end-products.

Although the invention has hereinabove been described with reference to a suitable embodiment given as an example only, it is apparent that such constructional modifications as are obvious to those skilled in the art, are to be construed as falling within the scope and spirit of this invention.

What I claim is:

1. Apparatus for soaking pulpwood comprising a long channel open at both ends thereof, the bottom of said channel being curved longitudinally and convexly downwardly from its ends toward its intermediate position on the arc of a circle having a long radius, a first conveyor means for continually feeding a pile of pulpwood into said channel, a second conveyor means for transporting said pile of pulpwood through said channel, said second conveyor means extending in spaced relation with res ect to said bottom of said channel and on an are concentric with said are of said bottom, a third conveyor means for discharging said pile of pulpwood from said channel, means for circulating water through said channel and means for controlling the temperature of said circulating water.

2. Apparatus for soaking pulpwood comprising a long channel open at both ends thereof, the bottom of said channel being curved longitudinally and convexly downwardly from its ends toward its intermediate position on the arc of a circle having a long radius, a first conveyor means for continually feeding a pile of pulpwood into said channel, a second conveyor means for transporting said pile of pulpwood through said channel, said second conveyor means extending in spaced relation with respect to said bottom of said channel and on an are concentric with said arc of said bottom, a third conveyor means for discharging said pile of pulpwood from said channel means for circulating water through said channel in counter current to the movement of said pulpwood, and means for controlling the temperature of said circulating water.

3. Apparatus for soaking pulpwood comprising a long channel convexly downwardly curved from its ends towards its intermediate position open at both ends thereof, said channel including a ceiling therealong the radius of curvature of said channel being large, a first conveyor means at the one end of said channel for continually feeding a pile of pulpwood into said channel, a second conveyor means located along said ceiling of said channel for transporting said pile of pulpwood therethrough, and a third conveyor means at the other end of said channel for discharging said pile of pulpwood from said channel, means for circulating water through said channel in counter current to the movement of said pulpwood, and means for controlling the temperature of said circulating water.

4. Apparatus for soaking pulpwood as in claim 3, wherein bars are provided on both sides of the supply opening of said channel, said bars being adapted to stop said first and second conveyor means when contacted by a log in said pile of pulpwood.

5. Apparatus for soaking pulpwood comprising a long channel convexly downwardly curved from its ends towards its intermediate position open at both ends thereof, said channel including a ceiling therealong the radius of curvature of said channel being large, a first conveyor means at the one end of said channel for continually feeding a pile of pulpwood into said channel, a second conveyor means located along said ceiling of said channel for feeding said pile of pulpwood therethrough, and

a third conveyor means at the other end of said channel for discharging said pile of pulpwood therefrom, said first, second and third conveyor means being curved concentrically with said channel, pumps for circulating water through said channel in counter current to the movement of said pile of pulpwood, and a heat exchanger for controlling the temperature of said circulating water.

6. Apparatus for soaking pulpwood as in claim 5, wherein said first conveyor means are vertically adjustable.

7. Apparatus for soaking pulpwood as in claim 6, wherein the end part of said second conveyor means adjacent said first conveyor means is hinged.

8. Apparatus for soaking pulpwood as in claim 7, wherein longitudinal rails are provided along said ceiling of said channel.

9. Apparatus for soaking pulpwood as in claim 7, including, means for driving said first and second conveyor means at speeds, proportional to the ratio of the radii of longitudinal curvature of the upper surface of said first conveyor means and of the under surface of said second conveyor means of curvature, means for driving said third conveyor means at a higher speed than those of said first and second conveyor means.

10. Apparatus for soaking pulpwood comprising, a long channel convexly downwardly curved from its ends towards its intermediate position open at both ends thereof, the radius of curvature of said channel being large, a ceiling above said channel, a first conveyor means at one end of said channel for continually feeding a pile of pulpwood into said channel, a second conveyor means located along said ceiling of said channel for transporting said pile of pulpwood therethrough, a third conveyor means at the other end of said channel for discharging said pile of pulpwood from said channel, means for circulating water through said channel in counter current to the movement of said pulpwood, said circulating means including a pump for pumping water from the bottom part of the supply end of said channel to the discharge end thereof and means for discharging said water through said ceiling back into said channel, and pumps for pumping water from the bottom part of said channel to points near the supply end thereof and discharging the same through said ceiling, and means for controlling the temperature of said circulating Water.

11. Apparatus for soaking pulpwood comprising a long channel convexly downwardly curved from its ends towards its intermediate position open at both ends thereof, said channel having a bottom, side walls and a closing top opposite said bottom, said channel being curved on an arc of a circle having a long radius, said channel being filled with water when said apparatus is in use, and conveyor means for conveying a pile of pulpwood into, through and out of said channel without changing the shape of said pile, said conveyor means including a conveyor extending along said channel beneath the top of the same, said conveyor being curved concentrically with said curvature of said channel.

References Cited in the file of this patent UNITED STATES PATENTS 1,475,198 Potthofi Nov. 27, 1923 2,057,982 Secondo Oct. 20, 1936 2,143,838 Boettger Jan. 17, 1939 2,249,792 Skinner July 22, 1941 2,580,420 Griswold Jan. 1, 1952 FOREIGN PATENTS 20,065/34 Australia Nov. 8, 1934