The invention relates to a tool for crushing coke in drums by means of high-pressure water jets, which has
a housing with a feed system for high-pressure water and
a housing wall with outwardly directed boring and cutting nozzles, out of the openings of which high-pressure water jets exit as well as
flow channels, which connect the feed system with the boring and cutting nozzles.
In oil refineries, the last, otherwise no longer usable, fraction of the crude oil is converted to coke. The conversion takes place by introducing this fraction to drums, which fill with coke as the operating time progresses. When the maximum fill level of the drums is reached, the coke is cut out of the drums.
This process, called “decoking”, is normally performed with high-pressure water jets, which crush the coke and flush it out of the drums. The tool for generating these high-pressure water jets is inserted into the drum from above via a boring rod. The “decoking” is performed in two sections. First, an opening is bored in the drum from top to bottom by the tool, then the tool is guided back to the top end of the drum and the coke is now crushed by the high-pressure water jets, which exit from it approximately at a right angle to the longitudinal axis of the tool.
The tool, which is for example known from DE 10 2011 053 852 A1, is thus designed for two operating states: first for the boring of an opening, which is required for moving the tool and the later discharging of crushed coke, and second for cutting the coke away from the cross-section of the drum. Accordingly, boring nozzles first send high-pressure water jets mainly parallel or also at an acute angle to an axis, which is formed by the boring rod and the opening formed during boring. Cutting nozzles in contrast generate high-pressure water jets, which are directed mainly at a right angle or at a flat angle to the axis formed by the boring rod and the opening in the drum and pass through a spiral channel for loosening, crushing and flushing out the coke when the tool with the rotating boring rod is lowered into the drum.
This results in that the cutting nozzles are inactive when the boring nozzles are activated and, vice versa, the boring nozzles are inactive when the cutting nozzles are activated. In interim periods, the boring and cutting nozzles can both be inactive.
No high-pressure water passes through an inactive nozzle from inside to outside so that there is a risk that coke particles are deposited on or in the outer opening of an inactive nozzle and the opening of the nozzle is plugged completely or partially so that the nozzle, when high-pressure water is again supplied to it from inside, cannot deliver a high-pressure water jet or only a high-pressure water jet, the jet shape of which is impaired.
It is known from WO 2012/109211 to permanently flush inactive nozzles via a bypass with pressure reduction and check valve for return flow prevention and for avoiding coke deposits on the nozzle opening. However, the construction effort for such a bypass system is relatively high. And, as a result, coke particles can still be deposited at least on the outside on the opening of the nozzle with the result that the delivery of a high-pressure water jet from the nozzle is impaired when the nozzle is activated again.
Thus, the object is to design a tool of the initially named type such that the opening of the boring and cutting nozzles is permanently protected and is kept free of deposits.
This object is solved according to the invention in that each of the openings of the boring or cutting nozzle is closable with a flap, which is adjustable between a dosed position and an open position.
According to this solution, the opening of a boring or cutting nozzle (with respect to common characteristics also just called “nozzle” below) remains dosed when no high-pressure water for generating high-pressure water jets is supplied to it from inside, that is when the nozzle is inactive, by a flap and is protected from mechanical wear from coke particles or the like. This protective effect of the flap in the dosed position does not only extend to the times when the tool is in operation but rather the flap forms a permanent protective cover so that the opening of the nozzle is not exposed to wear or is only exposed to relatively little wear.
As soon as the nozzle is activated, the flap is shifted from the dosed position into an open position by the pressurized water supplied to the nozzle from inside and the high-pressure water jet now exiting the opening of the nozzle, in which the flap dears the path for the high-pressure water jet exiting the opening. The flap can be produced as a pressure diecast part made of a steel substance.
As soon as the portion of the decoking process, which includes the high-pressure water jets exiting the nozzle, is complete, the nozzle becomes inactive, i.e. no more high-pressure water is supplied to it from the inside. This is the moment when the flap returns from the open position to the dosed position in which it closes the opening of the nozzle again.
The adjustment of the flap from the dosed position to the open position and vice versa is preferably enabled in that the flap is attached on one end of a nozzle channel next to the opening of the boring and cutting nozzle respectively with a swivel joint on the housing of the tool. In other words, the adjustment of the flap occurs through a pivot movement of the flap at the beginning and end of the active state of the nozzle.
The swivel joint of the flap is preferably fastened to the housing in front of the opening of the boring or cutting nozzle with a mainly horizontally positioned rotational axis when the tool is in operation, when it is a cutting nozzle, so that the flap is pivoted from the open position to the dosed position during the switch from an active phase of the cutting nozzle, in which the flap is held in the open position by the high-pressure water jet exiting the opening of the cutting nozzle, to an inactive phase of the cutting nozzle, in which no high-pressure water jet exits from the opening of the cutting nozzle, under the impact of the force resulting from its weight.
The actuation force for adjusting the flap from the dosed position to the open position thus results from the high-pressure water exiting the opening of the boring or cutting nozzle at the start of an active phase and the force required to pivot the flap from the open position into the dosed position, when the flap is no longer supported by the high-pressure water jet exiting the opening, results from the weight of the flap so that any controlling of the position of the flap from the outside is omitted and the adjustment takes place automatically.
However, the tool is preferably provided with a spring, which causes the pivot movement of the flap from the open position to the closed position and vice versa and holds the flap in the inactive phase of the boring or cutting nozzle in its closed position. The spring supports the pivot movement of the flap from the open position into the closed position or guides it along alone and holds the flap in the dosed position. However, the swivel joint of the flap can also only experience a support of the already present weight as closing force through a spring, when the weight generally exerts a closing effect like with cutting nozzles. In any case, a flap with a spring has the advantage of being similarly usable for closing and protecting cutting nozzles and boring nozzles and of being independent of the respective position of the nozzle.
The opening of the boring or cutting nozzle and the flap are preferably arranged on a nozzle flange attached on the housing. Should the opening of the boring or cutting nozzle be damaged or partially closed by coke particles despite the protective effect of the flap, the affected nozzle can be easily replaced in that the affected nozzle flange is loosened from the housing and replaced by a new flange.
The spring is preferably arranged in a protected position on the swivel joint, namely preferably as a leg spring in a recess on the upper flap end, where the flap flows out like a fork and the spring is arranged between the two fork legs.
The opening of the boring or cutting nozzle is preferably surrounded on the outside on the housing of the tool by a collar, which has an upper gap on its top side, in which the upper end of the flap is arranged with the swivel joint. The collar thus serves not only to attach or form the swivel joint of the flap but also simultaneously protects the opening and the flap itself from mechanical impairment from the outside. In this embodiment, the upper end of the flap is part of the swivel joint and is located in the upper gap of the collar. The collar is thereby preferably designed as one piece with the nozzle flange or is fastened, e.g. welded, on it.
A further embodiment of this structure of the swivel joint is characterized in that the swivel joint is made of a pin bridging the upper gap and anchored in the upper collar ends on both sides of the upper gap as rotational axis and a corresponding bearing bore in the upper end of the flap, with which the pin forms the swivel joint. Alternatively, the bearing bores can also be arranged in the collar ends and the pin itself in the upper end of the flap for formation of the swivel joint. In each case, an insensitive, reliably acting swivel joint is formed, which is constantly lubricated with pressurized water.
The collar preferably has opposite to the first gap a second lower gap on its bottom end, into which the lower end of the flap pivots when the flap assumes its closed position. In this manner, the lower end of the flap in the closed position lies protected from mechanical damage and is also immovable in this second gap in the collar. Thus, in the closed position of the flap, not only the opening of the nozzle is securely covered by the flap but also the flap itself is protected from mechanical damage and it lies almost immoveable within the collar with its ends in the first and in the second gap of the collar.
The flap can have a level, circular projection on its inside, which in the dosed position abuts against a projection of the boring or cutting nozzle surrounding the opening of the boring or cutting nozzle, wherein the projection has a bearing surface complementary to a bearing surface of the initially named projection. It is achieved through this design of the inside of the flap and the surrounding of the opening that the flap reliably closes the opening in the dosed position.
A very important further embodiment of the flap according to the invention results when the flap is designed in multiple parts and comprises opposite-lying respectively pivotingly mounted wings, which close the opening of the boring or cutting nozzle in the closed position like rotatable gate wings when they are adjacent to each other in a plane vertical to a nozzle channel and release the opening in that they are respectively rotated to the outside in a pivoting manner. Also in this case, the use of a spring, advantageously a torsion spring, is preferred for each wing so that the wings are pressed and held in the closed position in an inactive phase of the respective nozzle. Through the use of two opposite-lying wings as the flap, less space is needed for the respective pivot movement outside near the opening of the nozzle and the wings are more easily arranged close to the housing compared to a one-piece flap. As will be clarified below, the wings of a two-piece flap can be designed and arranged so that their movement profile lies entirely or almost entirely within the housing profile. In the case of a one-piece flap, it is almost impossible in the open position to keep its free end from protruding to the outside over the housing profile so that in unfavorable circumstances contact with the coke surrounding the tool cannot be completely excluded.
The wings are expediently arranged in a preferably rectangular recess of a protective cap attached in the area of the opening. The protective cap is advantageously attached to the nozzle flange so that the material processing necessary to receive the wings is easier to perform than a replacement of the protective cap when there is e.g. wear or the like on the wings. In any case, the wings are arranged secure and protected in the recess of the protective cap. The shape of a rectangular recess corresponds with the preferred shape of a wing pair and their movement play during the switch from the open position to the closed position and vice versa.
For the shape and for the dimensions of the recess, it is expedient if the width of the recess is greater than the diameter of the opening of the boring or cutting nozzle such that receiving areas for the wings are formed behind a ledge. In other words, receiving areas that are larger than the diameter of the opening connect to the opening so that corresponding ledges are created. The recess in the protective cap and the dimensions of the wings should thereby be coordinated so that the wings neither protrude over the recess in the open position nor in the closed position.
It is incidentally expedient that the wings are mounted opposite each other in a rotary manner with parallel rotational axes in the recess respectively by means of a pin. In this manner, a secure pivoting of the wings from the closed position to the open position and vice versa in the recess is ensured.
An important further embodiment of the multi-part flap consists in that the wings in the inactive phase of the boring or cutting nozzle are pressed into the closed position by means of torsion springs and in the active phase of the boring or cutting nozzle are pivoted and held by the high-pressure water jet against the spring effect in the open position, in which they release the opening of the boring or cutting nozzle. It is ensured in this manner that the wings are pressed into the closed position and held there above all in the inactive phase of the respective nozzle by the torsion springs. The torsion springs are thereby to be measured such that the wings are securely pivoted and held in the open position by the high-pressure water jet during the switch from the dosed position to the open position so that they release the opening of the boring or cutting nozzle and the high-pressure water jet can exit unhindered.
The narrow sides of the wings facing each other in the dosed position of the boring or cutting nozzle are preferably respectively designed rounded at at least one edge for pivoting the wings into the closed position. An unhindered pivoting of the wings from the open position to the dosed position and vice verse is possible through the rounding of this edge at each of the two wings. Without a rounding, that is with rectangular edges on the narrow sides facing each other, a pivot movement of the wings to the outside would not be possible because the radius from one edge to the rotational axis of a wing is greater than the radius from the middle of the narrow side to the rotational axis.
The invention also comprises a nozzle, both boring or cutting nozzle, for a tool for crushing coke in drums by means of high-pressure water jets, wherein the nozzle is closable with a one-part or multi-part flap, which is adjustable between a dosed position and an open position. Explanations for the nozzle according to the invention can be found in the preceding description of the tool according to the invention.
Moreover, the invention comprises a method for operating a tool for crushing coke in drums by means of high-pressure water jets, wherein the method is performed with a tool as described above.
Exemplary embodiments of the invention are explained below based on the drawings. The drawings show:
a a perspective view of a cutting nozzle with a multi-part flap;
b a perspective view of a cutting nozzle with a multi-part flap in a dosed position;
a a sectional view of a cutting nozzle provided with a multi-part flap in a closed position;
b a side view of the cutting nozzle of
c a top view of the cutting nozzle of
a a top view of a cutting nozzle as in
b a side view of a cutting nozzle with a multi-part flap as in
c a longitudinal sectional view of the cutting nozzle shown in
The tool 1 has a housing 2 with a housing wall 3, on the bottom side of which a bottom part 3b is fastened by means of screws 3c. A base plate 3d is attached to it via three bars 3f by means of screws 3e as bottom closure of the tool 1.
A feed system 4 for high-pressure water has an upper feed channel 4a, through which high-pressure water flows in past a switching device 4b through a control device 4c as well as through a valve device 4d to channel openings 4f, which are alternatingly dosed and opened by valve bodies 4e. The switching device 4b switches the control device 4c depending on a changeover pressure from a boring mode to a cutting mode and vice versa so that the channel openings 4f of channels 4g, 4h leading to cutting nozzles 5b and to boring nozzles 5a are closed or respectively opened alternatingly by the valve bodies 4e. The switching device 4b is known as well as the control device 4c with the valve device 4d, which shifts the valve bodies 4e over the channel openings 4f for closing or respectively opening them so that the representations for this are not described in further detail.
Cutting nozzles 5b that do not protrude over the housing wall 3 each engage in receiving openings 3a in the middle part of the housing wall 3 with a rectifier 5, the openings 7 of the cutting nozzles 5b being closed by a flap 8. This flap is adjustable respectively from a dosed position (
In the bottom part 3b of the housing 2, boring nozzles 5a engage in receiving openings 3a′, the opening 7 of which is also to be opened and dosed by means of a pivotable flap 8. The tool 1 is in the boring mode (
A cutting nozzle 5b with a larger dimension is shown in
The opening 7 of the cutting nozzle 5b is surrounded by a collar 14 protruding from the projection 24 of the cutting nozzle 5b, the collar 14 presenting an upper gap 16 on its upper end, to which are adjacent upper collar ends 14a, 14b. Diametrically opposed is a lower gap 17 of the collar 14 with corresponding lower collar ends 14c, 14d.
In the upper gap 16 of the collar 14, a swivel joint 11 is arranged, which consists of a pin 18 as a rotary axis bridging the upper gap 16 of the collar 14 and anchored in the upper collar ends 14a, 14b on both sides of the upper gap 16 of the collar 14 and a corresponding bearing bore 19 in the upper end of the flap 8. Alternatively, the bearing bores 19 can also be arranged in the upper collar ends 14a, 14b and the pin 18 itself in the upper end of the flap 8 for formation of the swivel joint 11. In this manner, as shown in
A preferred further embodiment of the nozzles is shown in
The operating mode of tool 1 and the method performable with the tool 1 are as follows:
As soon as the tool 1 is lowered into a drum (not shown here) filled with coke with the rotating boring rod (also not shown) and the coke quantity is reached in the drum, high-pressure water is fed to the boring nozzles 5a on the bottom side of the tool 1 via the flow channels 4h. The high-pressure water flows through the opening 7 of each boring nozzle 5a and pushes the flap 8 held by the spring 13 in the closed position out of its closed position and pivots it into the open position, so that a high-pressure water jet exits the boring nozzle 5a and the coke is crushed and a vertical central opening or respectively a corresponding channel can be cleared through the mass of coke. During this step of the method, the flap 8 is held in the open position by the high-pressure water jet 28 exiting the boring nozzle 5a, and the flaps 8 of the cutting nozzles 5b are held in the closed position by their springs 13. This position corresponds with the representations in
As soon as the central, vertical opening or respectively the channel in the coke mass of the drum is cleared out, the pressurized water infeed stops so that the boring and cutting nozzles 5a, 5b are dosed by the flaps 8. The tool 1 is now raised upwards through the opening with the boring rod. In the upper position of the tool 1, the crushing and clearing out of the coke begins via the drum cross-section, wherein the tool 1 hanging on the rotating boring rod travels a spiral path downwards. For this section, high-pressure water is fed to the cutting nozzles 5b so that their flaps 8 are pivoted out of the dosed position into the open position against the pressure of their springs 13 and high-pressure water jets 28 can freely exit the cutting nozzles 5b wherein the flaps 8 are held in their open position by the high-pressure water jets 28. While the tool 1 is in this cutting mode, the boring nozzles 5a are not activated so that their openings 7 are dosed by the flaps 8, which are spring pressurized.
As soon as the coke in the drum is completely crushed and discharged in this second process step, the pressurized water infeed is stopped completely so that the openings 7 in the boring and cutting nozzles 5a, 5b are closed and protected by the flaps 8, which are spring pressurized.
c show an important further embodiment of the design of the tool 1 described above. It is characterized in that the flap 8 for closing and releasing the opening 7 of the respective boring or cutting nozzle 5a, 5b is designed in multiple parts, is namely replaced by two wings 8a, 8b, which work together to assume the function of the one-part flap 8 described above. The division of the flap 8 into two opposite-lying, respectively pivotingly mounted wings 8a, 8b, which close the opening 7 of the boring or cutting nozzle 5a, 5b like rotatable gate wings in the closed position and release the opening 7 when pivoted to the outside, causes structural differences with respect to the exemplary embodiment described above, which will be explained below with reference to
Because the area of the wings 8a, 8b of the boring and cutting nozzles 5a, 5b in
It results from
In the centered position of the protective cap 29, a recess 32 that is rectangular in cross-section (
The wings 8a, 8b are pressed respectively into their dosed position by a torsion spring 36, for which their facing narrow sides 37a, 37b are rounded above all on the upper edges 38a, 38b visible in
The described design of the multi-part flap or respectively of the wings 8a, 8b that work together applies the same to boring and cutting nozzles 5a, 5b.
The transition from the dosed position to the open position and vice verse is performed in this embodiment analogously to the first exemplary embodiment described above with a one-part flap 8. If e.g. the boring nozzles 5a are dosed in the cutting mode, the wings 8a, 8b, as shown e.g. in
A more detailed description of the function and the thereby resulting procedural method is not necessary in light of the comprehensive explanations for the first exemplary embodiment.
The above description of the exemplary embodiments simultaneously illustrates examples of the nozzle according to the invention and of the method according to the invention.
Number | Date | Country | Kind |
---|---|---|---|
10 2013 108 755.8 | Aug 2013 | DE | national |
10 2014 100 834.0 | Jan 2014 | DE | national |