US2006777A - Wood preserving apparatus - Google Patents

Description

July 2, 1935.

G. B. SHIPLEY WOOD PRESERVING APPARATUS Filed Nov. 13, 1953 /:0571" 7| n r9/27% I' f 1 Y' 19 21 I a 3 l' 4 l/a IL- 7a\ 3.9 l 44 g2 11 T"- L 'I I 3233 L .L I 741/31 6 /Jl- "i ML y:

2 j.;l ,2.aI

"1l 2 2| 6 17 a $66k l ,Il A M32? k h i ,u l ze@ 41 f rH 345% .sa

y W'ITNESSES y I ad, zam im [a Patented Jb 2, 1935 UNITED STATES PATENT OFFICE 2,006,777 woon PnEsEiwiNG ArrAnA'rUs emit 1i, Shipley, Pittsburgh, Pa; Application Npvembr 13, 1933, serial No. 697,784

claims. (oies-12) Wood-treating plants in use today are gen- 5 erally complicated structures made up 4of a ,va-

riety of tanks, pressure and vacuum pumps, numerous lengthy pipe lines, and other elements. Consequently, such plants are large and expensive, with much to getout of order and to keep in repair, and each requires several skilled men' to operate it. It can thus be seen that many industries which would like to use wood-'treating plants are prevented from doing so by their size and excessive cost. Also, it has not been feasible or economical to install such equipment for field operations. p,

It is among the objects of this invention to provide a Wood-treating plant of comparatively simple inexpensive and compact construction, which uses a minimum number of elements, which can be operated by the average workman without confusion or assistance, may be erected and operated at substantially any desired point and is particularly adapted for eld operation, 1s eflicient and economical to operate, and utilizes steam in its operation, whereby the customary pumps, condensers andv the like heretofore neceessary are dispensed with.

The invention may be described in connection with the accompanying diagrammatic drawing,

f of which Fig. 1 is a side view of one embodiment;

Fig. 2 a plan view of the treating cylinder and its connections, taken on line II-II of Fig. 1, and Fig. 3 a modified form of pressure measuring tank.

Referring to Figs.' 1 and 2 of the drawnig, the embodiment shown includes a horizontally disposed wood-treating cylinder I, having a conventional sealing door 2 at one end, and it may be mounted on a suitable foundation, not shown. Disposed above the treating cylinder is a large tank divided into two smaller tanks 3 and 4 by a transverse wall 5.

containing a woodlpreservative solution, such as creosote, solution of zinc chloride, or Wolman salts, or the like. The left-hand tank 3 is a pressure measuring tank containing additional preservative solution on which pressure is exerted to force preservative into the wood being treated in the treating cylinder, with which tank 3 can be put into communication.

Although the storage and pressure measuring tanks need not necessarily be joined, combining them in one large cylinder in the above manner saves space, makes the apparatus more compact, and reduces expense since wall 5 serves as an end Wall for two tanks. The large double-tank cylinder and the treating cylinder are, therefore, the only large pieces of equipment used in this The right-hand tank 4v is a combined storage, working and Rueping-.tank

embodiment of the invention; the rest of the elements consisting of pipes, valves" and an ejector which are shown, diagrammatically in the drawing. With only the two cylinders to be interconnected, it Will be seen that the connecting pipe lines are relatively short and simple.

A particular feature of the invention resides in the use of fluid pressure for` applying impregnating pressure and vacuum, thereby rendering urmecessary the multiplicity of pumps and associated equipment heretofore needed with such apparatus. This further simplifies and cheapens the apparatus, as may be understood better from the following detailed description of the embodiment shown in Figs. 1 and 2.

Referring in particular to the piping, a conduit II connects the bottom of storage tank 4 to the bottom of treating cylinder I for conducting preservative solution byv gravity to the treating cylinder and for returning preservative to the storage tank, and a branch I2 connects conduit II to a drain line I3 which empties to any suitable point, e. g., a sump. Conduit II is of suiiicient size to permit rapid iilling and emptying of the treating cylinder The bottom of pressure measuring tank 3 is connected to the bottom of .also'to a pipe I9 which is connected at its upper end to the top of pressure measuring tank 3 and at its lower end toA a conduit 2| the lower end of which acts as a blow-off line and opens into a sump, for example. The upper end of conduit 2| is in communication with the top of storage tank 4, and an upper branch 22 connects it to the manifold. Between this branch and the juncture with conduit I9 is a short branch 23 from which a. conduit 24 leads to manifold I'l. Another conduit 26 extends from the short branch 23 to the top of the pressure measuring tank, and still another conduit 27 extends downward from branch 23 and opens into afunnel connected to the upper end of drain pipe I3. A conduit 29 (Fig. 2) connects conduit 24 to the top of the treating cylinder.

It will be observed that there are several other pipes leading to and from manifold I1. One of these 3l, connected to the end of manifold I'l leads from a source of fluid pressure, such' as air or steam, and conduits 32 and 33 between supply conduit 3I and conduit 22 lead to heating coils in the pressure measuring and storage tanks for heating the wood preservative which they contain. Conduit 34 leads from the bottom of the manifold and is connected to a heating coil in the treating cylinder, and conduit 36 leads to a perforated coil in the treating cylinder through which steam is introduced for steaming green wood to open its cells for the reception of the preservative. As all the connections thereto are not shown in the drawing.

A conduit 31k is connected to a mixing pit, not shown, suitably adjacent the apparatus, in which the preserving solution may be prepared before admission to the storage tank. Conduit 33 is connected to the pressure inlet of an ejector 39 whose suction side is connected by 'a conduit 42 to the top of the treating cylinder. Conduit 4I, connected to manifold I1, acts as a drain pipe. The outlet of. the ejector is connected by a conduit 43 to a waste conduit 44 having a depending portion through whichvcondensate drains.

. In operating this wood-treating apparatus, loads of wood to be treated are run on tram cars into treating cylinder I, whereupon door 2 is tightly closed. A valve Il, next to manifold I1, in pipe I6 is-now opened to lconnect the source of uid pressure, in line 3i, preferably steam, to

the top ofthe pressure measuring tank through the manifold and conduits I3, Il and Il, valve .5I in pipe I! being closed at this time. Valve 52 in pipe I I is then opened to permit the preserving solution in storage tank 4 to flow by gravity into and fill the treating cylinder.

After the cylinder has ,been lled, valve 52 is closed and a valve 53 in pipe I4 is opened, thereby establishing communication between thebottomV of the pressure measuring tank and the bottom of the treating cylinder through pipes I4, It, I2'

and I I. Valve 54, in pipe I3 between pipes I3 and I4, is closed duringthis-stage to keep the pressure fluid from entering `the bottom of tank 3. The fluid pressure applied t o` the top of the pressure measuring tank acts ythrough the preservative solution therein to force the preservative in the 1treaiieircilg cylinder intothe cells of the wood being rea f 'I'he pressure is regulated to meet the requirements of the particular kind of wood being ynated by the preservative, which is held Aunder pressure by the fluid pressure fluid in tank 3, the pressure supply is shut olf before it reaches the manifold, and valve 53A in pipe I4 is closed. Valve 52 is then opened to again establish communication between the bottoms of the storage tank and the treating cylinder, and valve 51 inl pipe 24 is opened, valve 58 therein being closed.'

This permits the excess pressure fluid in the top of the pressure measuring tank to,r expand and enter the top of the treating cylinder through pipes I 9 and I6, manifold I1, and pipes 24 and 29, thereby forcing the preservative solution from the treating cylinder through pipe I I and back into storage tank 4.

If more solution is b lov'n back'than the storage tank can hold, it will overflow through pipes '2I, 23 and 21 and start flowing into drain pipe I3., valve 6I in pipe, 2iv below pipe 23 being closed. When it is seen'` to ow fromvthe lower end of pipe 21 into funnel 28, valve 5|) is closed to stop the blow back', and valve 5I is opened to permit the remaining pressure in tank 3 to escape through the outlet of pipe 2l. Valve 62 in pipe 21` is open an overflow conduit between tanks 3 and 4. Fluid under pressure is againadmitted to the manifold through pipe 3i, the uid entering the top of the treating cylinder through pipes 24 and 29 to blow the remainder of the 4solution back into the storage tank from which it overflows into the pressure measuring tank.

For the purpose of relieving 'pressure in the treating cylinder when that is desired, a conduit 83 is connected to its top and to a pressure outlet pipe -39 suitably disposed beside vertical outlet pipe 44. Conduit 68 is controlled by a valve 10 therein.

Conduit 22, connecting manifold I1 to conduit y, permits fluid pressure'to beapplied to the top of storage tank 4. Y

In order to withdraw the excess amount of preservative from the treated wood to prevent drippage and waste, a vacuum is applied to the treating cylinder by closing valves 51 and 52 and opening valve .3i .in pipe 33 to. permit the high pressure fluid to passthrough ejector 39 :and pipe 43 to the vertical'outlet pipe 44, therushof fluid through the ejector-creating avacmirn-,fin1the`y the storage tank. The difference in readingsvinl dicates the amount of preservative used.

Although it is preferred to operate the apparatus solely by steam, as just described, the impregnating pressure may be obtained by and the ejector operated with compressed air. In such a case, if the air pressure available is not sumcient 1y great to aiiord the necessary pressure, it may be desirable to connect a combined compressor and vacuum pump to supply-pipe 3i in order to increase the incoming air pressure if necessary, or to hold'the vacuum in the -treating cylinder after its air has been initially exhausted by the ejector. ,I For the latter purpose the pump may be connected to outlet pipe 43 of the ejector.

However, it is more advantageous to operate the apparatus by steam pressure, because steam is usually available, e. g., for use in heatingthe preservative, as in the tanks and cylinder. If steam is not so readily available, it can be supplied by a small high-pressure steam boiler. In any event, the use of steam is highly advantageous, because it is capable of performing the various duties heretofore performed by pumps, compressors and the like, such forcing the preservative solution from one tank to another, creating pressure in the tanks, and creating a vacuum -in the treating tank or cylinder. For this to 250 pounds, or a superheated steam at those pressures, is suillcient.

4Dueto the area of preservative exposed to the pressure iluid in the pressure measuring tank and also due to the depth of the solution therein, dimculties may be experienced both from a high rate of steam condensation and also from strain on the tank due to diierences in temperature .of the preservative and tank lbetween the upper and lower portions which induces diierential expansion and consequent strain on the tank. A form` of pressure measuring 'tank which minimizes these difculties and can be used in place o! tank 3 is shown in Fig. 3. It consists of a plurality of vertically disposed cylindrical tanks 8| of relatively small cross-sectional area, such as large diameter pipe, the combined capacities of the tanks being substantially equal to the capacity of tank 3.

These small tanks are connected in series, i. e., the bottom of one to the top of the other. Most suitably they are arranged in staggered relation with the bottom of the rst tankconnected by pipe 86 to the top of the second tank whose bottom is connected by pipe 81 to the top of the third tank, and so on along the line. Pressuresupplying pipe |9 is connected to a pipe 88 which extends along the line of small tanks. A short pipe 89 leads from pipe 88 to the top of the iirst tank to apply uid pressure to the preserving solution contained therein. As the volume of the rst tank is very much lessthan that of tank 3, the rate and amount of steam condensation therein is also less. To prevent this volume from becoming any greater than that of one small tank as the preserving solution is used up in impreg- `nating wood, means is provided for cutting emptied tanks out of the line.

This means consists of branch pipes 9|, 92 and 93 which lead from pipe 88 to each respective pair of tank-connecting pipes, and of a system of valves, all of the valves in the branch pipes normally being closed. Thus, when the rst tank 8| is emptied, valve 94 in its lead-in pipe 89 is closed, and valve 95 in pipe 86 between' tank A8| and the juncture of pipes 86 and 9| is also closed. This cuts out tank 3|. Valve 96 in pipe 9| is then opened to permit the pressure fluid to enter the top of the second tank through pipe 86. When this tank is emptied valve 91 in pipe 8l is closed, valve 96 is closed, and valve 98 in pipe 9| is opened. This procedure is followed as each successive tank is emptied.

As a result of cutting empty tanks out of the pressure line it will be seen that the area of preservative solution to which the steam is applied is never greater than the interior area'of a single tank 8 I. Consequently, the rate of steam condensation is considerably less than it would be if the large pressure measuring tank 3 were used. Also, due to the smaller volume of each tank 8|, the differences in temperature of the preservative and tank between the upper and lower portions are not so great, thus reducing strain on the tank.

Another, but more undesirable arrangement of tanks 8| is made by connecting them in pary allel instead of in series.

According to the provisions of the patent statutes, I have explained the principle and mode of operation of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of t'ie appended claims, the invention may be practiced otherwise than as specifically illustrated and de scribed.

I claim:

1. The combination in wood-treating apparatus comprising a treating cylinder, a storage and working tank, a conduit connecting the bottom of the storage tank to the bottom of the treating cylinder, an ejector connectedv to the top oi' the treating cylinder, and a conduit connecting a source of uid pressure to the ejector for evacuating the treating cylinder, of a plurality of relatively small pressure measuring tanks, vconduits 'serially connecting said pressure measuring tanks end to end, a conduit connecting said source of fluid pressure and the tops of the pressure'measuring tanks, a conduit leading lfrom the bottom of the last pressure measuring tank in line to the treating cylinder, and valves arranged for cutting out each successive pressure measuring tank as it is emptied.

2. The combination in wood-treating appa- Aratus comprising a source of fluid under pressure, a treating' cylinder, a storage and working tank, a conduit connecting the storage tank to the treating cylinder, and means for evacuating the treating cylinder, of a plurality of relatively small pressure measuring tanks, a conduit connecting said source of fluid pressure to one end of each of the pressure measuring tanks, a conduit connecting the other end of each of the pressure measuring tanks to the treating cylinder, and valves arranged for admitting fluid pressure from said source to one pressure measuring tank at a time and for cutting that tank out of line when it is emptied.

3. 'Ihe ,combination in wood-treating apparatus comprising a source of fluid under pressure, a treating cylinder, a storage and working tank, a conduit connecting the storage tank to the treating cylinder, of a plurality of relatively small pressure measuring tanks, conduits serially connecting said pressure measuring tanks end to end, a conduit connecting said source of fluid pressure and the tops of the pressure measuring tanks, a conduit leading` from the bottom of the last pressure measuring tank in line to the treating cylinder, and valves arranged for cutting out each successive pressure measuring tank as it is emptied.

4. The combination in wood-treating apparatus comprising a treating cylinder, a storage and working tank, a conduit connecting the bottom of the storage tank to the bottom of the treating cylinder, an ejector connected to the top of the treating cylinder, and a conduit connecting a source of steam pressure. to the ejector for evacuating the treating cylinder, of a plurality of relatively small pressure measuring tanks, conduits serially connecting said pressure measuring tanks end-to-end, a conduit connecting said source of steam pressure and the tops of the pressure measuring tanks, a conduit leading from the bottom of the last pressure measuring tank in line to the treating cylinder, and valves arranged for cutting out each successive pressure measuring tank as it is emptied.

5. The combination in wood-treating apparatus comprising a source of steam pressure, a treating cylinder, a storage and working tank,

`and a conduit connecting the storage tank to the treating cylinder, of a plurality of relatively small pressure measuring tanks, conduits serially connecting said pressure measuring tanks end-to-end, a conduit connecting said source of steam pressure and the tops of the pressure measuring tanks, a conduit leading. from the bottom of the last pressure measuringvtank in lline to the treating cylinder, and valves arranged for cutting out each successive pressure measuring tank as it is emptied.l

GRANT B. SHIPLEY.

Images