Abstract:
Method and device for transporting flowable building materials which are flowable in a heated state. A pump and a pipe connected to the pump may be provided. The pump and the pipe may be heated by at least one heating device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation of U.S. Application No. PCT/EP02/14204, filed Dec. 13, 2002, which claims the priority of German Application No. 202 07 274.6, filed May 3, 2002, and which U.S. Application No. PCT/EP02/14204 claims the priority of European Patent Application No. 01 129 925.2, filed Dec. 16, 2001, and each of which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The invention relates to a process and an apparatus for conveying construction materials which are flowable in their heated state. The invention also relates to a pump and a pipe for carrying out the process according to the invention.  
       BACKGROUND OF THE INVENTION  
       [0003]     In the construction industry a plurality of building materials are used which can basically be divided into natural and artificial building materials. In the construction of apartment buildings, in particular, asphalt or pourable asphalt is used as a flooring compound as it is non-flammable and provides good soundproofing. Pourable asphalt is a mixture and consists of about 8 to 10% bitumen and about 90 to 92% minerals with a particle size of 5 to 11 mm.  
         [0004]     A disadvantage of pourable asphalt is that it has to be used in a liquid or flowable state and for this it has to be at a temperature of about 250° C. The hot pourable asphalt mass therefore has to be conveyed to the building site as quickly as possible in asphalt boilers and then has to be taken directly to the place of installation in the building without the compound cooling too much.  
         [0005]     Currently, it is predominantly transported around the building site in wooden vessels such as wooden buckets or wooden crates as transporting units. These are usually carried to the place of use by means of a carrying yoke. In addition, sloping hoists with suitable platforms are used to convey the wooden units to the particular window of the building under construction. However, for a considerable part of the distance the wooden containers have to be carried by hand. This is very time-consuming and strenuous, as the person responsible has to carry the heavy, hot wooden container to the place of installation quickly before the asphalt contained therein has cooled down too.  
       OBJECTS AND SUMMARY OF THE INVENTION  
       [0006]     In the light of this, a process for conveying construction materials which are flowable in the heated state is proposed wherein a pump and a pipe connected to this pump are provided, and the pump and the pipe are heated.  
         [0007]     The pump is preferably provided in the vicinity of the container in which the supply of hot asphalt is kept and conveys it directly to the place of use through the pipe connected thereto. If the asphalt is delivered by lorry it is possible to drive the lorry right up to the pump or, in the case of a mobile pump, to move the latter to the lorry and connect it up.  
         [0008]     As both the pump and the pipe are heated, it is possible to prevent the asphalt or the construction material being conveyed from cooling down too much. The construction material is thus taken directly to the place of use in a workable state.  
         [0009]     Tests have shown that good results can be achieved with pipe lengths of up to 50 m and over a height of up to 30 m. However, the process according to the invention can also be used with longer pipes and bridging greater differences in height. The power of the pump, which is able to both pump out and suck in, simply has to be matched to the length of the pipe.  
         [0010]     At certain times, preferably at the end of a working day, it must be ensured that the pump and conveying pipe are cleaned. This can be done, for example, using a suitable cleaning fluid and/or a cleaning object, such as a ball, for example, a so-called scraper, which can be forced or sucked through the pipe by pump action or by air pressure.  
         [0011]     Advantageously, a common heater is provided for heating the pump and the pipe. The heater used may be, for example, a bar burner which initially heats the pump. The exhaust air formed as the pump is heated is used to heat the pipe.  
         [0012]     Preferably, gaseous and/or liquid heat carriers are used to heat the pump and the pipe. These heat carriers are usually passed through heating channels which surround the pipe and the pump. Another possibility is to heat the pump and/or pipe electrically, e.g. using electric heaters. If electric heaters are used, a unit for controlling or regulating the temperature is preferably provided.  
         [0013]     With the process according to the invention it is possible to maintain flowable construction materials at a substantially constant temperature and even to convey these materials upwards.  
         [0014]     The apparatus according to the invention for conveying construction materials which are flowable in the heated state comprises a pump and a pipe connected to this pump. The pump and the hose are heatable by means of at least one preferably electrically operated heater.  
         [0015]     The pipe used may be a tube or a hose, e.g. made of a flexible heat-resistant material. When choosing the material it is important to note that it has to withstand temperatures of from 220° C. to 300° C. A special steel alloy may also be used as the material.  
         [0016]     It is advantageous to use a common heater to heat both the pump and the pipe. In one embodiment of the apparatus according to the invention this common heating apparatus is a bar-type burner which is used initially to heat the pump while the pipe is heated by the exhaust air produced on heating the pump.  
         [0017]     Preferably, electrical heaters are provided for heating the apparatus according to the invention.  
         [0018]     The pump according to the invention serves to deliver materials which are flowable in the heated state, and can be heated by a heater. Heating channels are preferably provided for this purpose. These heating channels ensure that the construction material contained in the pump does not cool off too much. It may optionally be necessary to pre-heat the pump before filling it with the construction material which is to be conveyed. The pump can be used to pump the construction material into the pipe provided or to suck up material contained in the pipe.  
         [0019]     According to one embodiment of the invention the pump builds up the pressure needed for conveying the construction materials with a worm conveyor and is thus a so-called worm conveyor pump which usually has an endless worm or screw conveyor cut into a cylindrical shaft, the worm conveyor being used to transport flowable materials.  
         [0020]     The worm conveyor may be directly heatable, i.e. by passing a heat carrier through the worm conveyor, for example, or the latter may contain an electrical heating element. Alternatively, electrical heating elements or heat carrier lines may run in or over the walls of the pump.  
         [0021]     In an alternative embodiment the necessary pressure is built up by a piston or a stopper, while the stopper or piston may be adapted to be forced right through the pipe.  
         [0022]     Advantageously the worm conveyor according to the invention converges conically or tapers at one of its ends, specifically at the end which is to be connected to the pipe during use, this connecting end being matched in diameter to the attached pipe.  
         [0023]     The pump according to the invention preferably comprises an inner pipe and an outer pipe which contains it, the worm conveyor being mounted in the inner pipe and heating elements being accommodated in or on the outer pipe. This ensures easier access to the pump for maintenance.  
         [0024]     The pipe according to the invention can also be heated by means of a heater provided for this purpose. Heating channels may be provided, surrounding the pipe. The heat carrier provided is then passed through these channels, for example, ensuring that the construction material contained in the pipe does not cool down.  
         [0025]     The heating channels are preferably applied in a spiral around the pipe, as is necessary for mobility or flexibility in a pipe made of a flexible material, e.g. a hose. If for example the pipe is in the form of a spiral hose, heating elements, e.g. electric heat conductors, may be provided extending in a similar configuration to the hose. This results in a smaller radius of bending of the hose.  
         [0026]     According to one feature of the invention an end cap is provided on the pipe for the removal of exhaust air. A regulator which regulates the speed of the pump during delivery and intake may also be provided in the end cap.  
         [0027]     Preferably, the pipe is enclosed in an insulating layer. The heating elements are then located between the pipe wall and the insulating layer.  
         [0028]     A protective layer protects against mechanical influences and may provide additional insulation.  
         [0029]     According to one feature of the pipe according to the invention it is made up of sections which can be connected to one another. These sections are preferably to be heated separately. Expediently, each section has a temperature sensor, e.g. a PT-100, which detects the temperature in this section. A preferably central regulating device, optionally connected via a bus system, then allows simultaneous or parallel temperature regulation for each of the sections.  
         [0030]     The sections may be from 1 to 10 m long, for example.  
         [0031]     The pipe according to the invention preferably has an inner and an outer hose or an inner and an outer tube. The inner hose is expediently constructed as a corrugated or spiral hose made of stainless steel. The outer hose acts as insulation. In addition, it may be enveloped in a protective jacket.  
         [0032]     Between the inner and outer hoses are typically found the heating pipes or heating elements. A temperature sensor rests directly on the inner hose.  
         [0033]     The use according to the invention envisages the use of the apparatus according to the invention for conveying flowable construction materials such as pourable asphalt, for example.  
         [0034]     Further advantages and embodiments of the invention will become apparent from the specification and the accompanying drawings.  
         [0035]     It will be understood that the features mentioned above and those still to be described hereinafter may be used not only in the particular combination specified but also in other combinations or on their own, without departing from the scope of the present invention.  
         [0036]     The invention is illustrated in the drawings by means of exemplifying embodiments and is hereinafter explained more fully with reference to the drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0037]      FIG. 1  shows a preferred embodiment of the apparatus according to the invention in diagrammatic representation,  
         [0038]      FIG. 2  shows another preferred embodiment of the apparatus according to the invention,  
         [0039]      FIG. 3  shows a preferred embodiment of the pipe according to the invention in cross section,  
         [0040]      FIG. 4  shows a detail of a pipe according to the invention,  
         [0041]      FIG. 5  shows a preferred embodiment of the pump according to the invention in diagrammatic representation,  
         [0042]      FIG. 6  shows another preferred embodiment of the pump according to the invention,  
         [0043]      FIG. 7  shows a detail of another preferred embodiment of a pump according to the invention, and  
         [0044]      FIG. 8  shows another preferred embodiment of the apparatus according to the invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0045]     In  FIG. 1 , a preferred embodiment of the apparatus according to the invention is diagrammatically shown, generally designated  10 . The drawing shows a pump  12  and a pipe  14  connected to the pump  12  via a connector  16 .  
         [0046]     The pump  12  is constructed as a worm conveyor pump  12  with a cylindrical shaft  18  and a worm conveyor  20  or screw conveyor  20  rotatably mounted therein. The worm conveyor  20  is driven by a drive motor  22 , or by an electric motor, via a bearing block  24 , i.e. rotated about its longitudinal axis. The material to be conveyed is introduced into the pump  12  through a hopper or funnel  26  and from there is forced towards the connector  16  and the pipe  14  by the rotation of the worm conveyor  20 . The pipe  14  ends at the place where the material or construction material is to be worked, which means that the material no longer has to be transported manually.  
         [0047]     In order to allow this to happen with a construction material which has to be heated up, in the apparatus  10  shown there is a heater  28  which heats both the pump  12  and also the pipe  14  via a feed line  30 . This is preferably done by means of a heat carrier which supplies the heat generated by the heater  28  to the pump  12  and the pipe  14 .  
         [0048]     Usually, the pump  12  is heated first and the exhaust air produced is used to heat the pipe  14  via the feed line  30 .  
         [0049]      FIG. 2  shows another embodiment of the apparatus according to the invention. The apparatus  40  has a pump  42  of mobile construction, i.e. it can be moved along on a wheel  44  or wheels  44  to a tank  46 . The mobile pump station  42  is connectable to a pipe (not shown) via a connector  48 .  
         [0050]     The pump  42  comprises an elongated cylindrical shaft  50  and a worm conveyor  52  located therein which is to be driven by a motor  54  via a bearing block  56 . In the embodiment shown the motor  54  and the bearing block  56  are movable together with the pump  42 . However, it is certainly possible for only the pump  42  to be mobile and for the motor  54  and/or the bearing block to be fixedly mounted in one place.  
         [0051]     The construction material contained in the tank  46  is let into the pump  42  through a supply line  58  and an actuating device  60 . The actuating device  60  initiates or controls this process. The supply line  58  may also be heatable.  
         [0052]      FIG. 3  shows a cross section through an advantageous embodiment of a pipe according to the invention which is designated  70 . A wall  72  defines the cross sectional area of the pipe  70  through which the typically viscous material to be conveyed is pumped. The wall  72  is surrounded by a heating jacket  74  which is in turn made up of four heating channels  76  which totally surround the wall  72 . A heat carrier or heating medium is conveyed through these heating channels  76  which preferably run in a spiral. The heat carrier may be, for example, air, oil, particularly thermal oil, or water.  
         [0053]     The pipe  70  is surrounded by an insulating layer  78  which ensures that the heat energy is not excessively given off to the surroundings.  
         [0054]     In the embodiment shown the heating jacket  74  is wrapped around the wall  72  of the pipe  70 . However, it is also thoroughly possible for heating pipes to be provided already in the wall  72  of the pipe  70 , through which the heat carrier is conveyed. Another possibility is to provide electrical heating elements in or on the wall  72  of the pipe  70 .  
         [0055]      FIG. 4  shows a detail of a pipe  80 , specifically the end portion. The Figure shows a heating jacket  82 , in which heating channels are provided, surrounding the pipe  80 . A handle  84  allows a workman to bring the end of the pipe directly to the place of use. This handle  84  is hollow so that the exhaust air can be recycled back through an exhaust pipe  88 , as shown by arrows  86 . A sealed system can thus be produced.  
         [0056]      FIG. 5  shows a pump  90 , namely a worm conveyor pump  90 . This is made up of a shaft  92  and a worm conveyor  94 . A heater  95  is also shown. Underneath the pump  90  and along it runs a heating element  96  actuated by the heater  95  which ensures that the pump  90  can be heated over its entire length.  
         [0057]     The worm conveyor  94  comprises a shaft  98  and blades  100  mounted on the shaft  98 . The shaft  98  which defines the longitudinal axis of the worm conveyor  94  may be of hollow construction so that a heat carrier can be passed through it and in this way the worm conveyor  94  can be heated directly. According to another alternative, an electrical heating element is provided in the shaft  98 . A heating element of this kind may of course also be installed in or on the wall of the shaft  92 .  
         [0058]      FIG. 6  shows another pump  110  which again is made up of a shaft  112  and a worm conveyor  114 . Alternatively to the worm conveyor pump  110  shown here, a vane pump may also be used in the apparatus according to the invention.  
         [0059]      FIG. 6  also shows a heating apparatus  116  which is connected to a heating jacket  118 . This heating jacket completely surrounds the shaft  112  of the pump  110 . Heating channels may in turn be provided in the heating jacket  118 .  
         [0060]     The pump ( 110 ) is safely heated in this way. The exhaust air produced can be fed through a feed line  120  into a pipe (not shown).  
         [0061]      FIG. 7  shows a detail of another pump according to the invention, generally designated  130 . It can be seen that this pump  130  comprises an inner tube  132  and an outer tube  134 , the inner tube  132  being received within the outer tube  134 .  
         [0062]     In the inner tube  132  is mounted a worm conveyor  136  for conveying pourable asphalt contained in the pump.  
         [0063]     In or on the walls of the outer tube  134  are heating elements  138 , in this case electrical heating elements  138 , which enable the pourable asphalt contained in the pump to be maintained at a constant temperature. This temperature is monitored, by a temperature sensor  140 , e.g. a PT-100.  
         [0064]      FIG. 8  diagrammatically shows another apparatus  150  according to the invention. It comprises a pump  152  and a pipe  154  connected thereto.  
         [0065]     It can be clearly seen that the pump  152 , in this case a worm conveyor pump, converges conically towards one of its ends. This conically convergent end  156  serves for connection to the pipe  154 . The worm conveyor in the pump  152  may be shaped accordingly.  
         [0066]     The pipe  154  comprises an inner hose  158  and an outer hose  160 . Between these two are provided heating elements  162  which are preferably arranged close to the inner hose  158 .  
         [0067]     Directly mounted on the inner hose  158  is a temperature sensor  164  which can be used to monitor and regulate the temperature in the inner hose  158  and hence the temperature of the construction material conveyed.  
         [0068]     There are various possible ways of heating the pump according to the invention and the pipe according to the invention. The procedures illustrated are only a selection and obviously may be combined with one another in any desired manner.  
         [0069]     While this invention has been described as having a preferred design, it is understood that it is capable of further modifications, and uses and/or adaptations of the invention and following in general the principle of the invention and including such departures from the present disclosure as come within the known or customary practice in the art to which the invention pertains, and as may be applied to the central features hereinbefore set forth, and fall within the scope of the invention or limits of the claims appended hereto.