Technical field

The device is designed for cleaning of tanks for petroleum products and can therefore be applied in facilities where such products are produced and/or sold.

Prior art

Tanks are usually cleaned from petroleum products and contaminants manually by people who go into the tank and clean it from the inside. This activity is harmful to human health so cleaners have to wear gas masks and protective clothing.

Attempts have been made to make human labour easier by using different tools and devices so that the human can be replaced by mechanized and somewhat automated devices thus minimizing the human activity to bare control and supervision functions.

Well-known is the device for cleaning of horizontal tanks from the publication of utility model DE 20 2009 009 419 U1 , which includes a self-propelled trolley that goes into the lying tank. The trolley is driven by a pneumatic motor, the latter receiving supply of compressed air from an external compressor through a hose whereas there are external controls for the supply of compressed air into the hoses.

The trolley moves only in one direction and there is no driving mechanism for the reverse movement, which is carried out by means of a towing device or by pulling the existing hoses and cables. The pneumatic motor is connected through a toothed belt or a chain to a gear located on a drive axle whereas the toothed belt or the chain covers both drive axles, each drive axle being connected to the motor drive shaft, or just one axle driven by the drive shaft of the motor, the two drive axles being connected to each other by another drive chain.

The trolley presents two drive axles at a distance from each other in the movement direction equipped with two outlying fixed wheels each. The wheels are equipped with runners located at a distance above the base plane of the wheels and bent forward or back in the movement direction slanting and/or rounded upwards. All four wheels are driven synchronously. Such a synchronous drive of all wheels from one side makes sure that the trolley will move even in the presence of precipitations on the bottom of the tank, and from the other side it is more cost-effective and simple. In the movement direction there is at least one end buffer at the front of the trolley.

On the trolley is installed a high-pressure cleaning head connected to an external device supplying water under high pressure, which is connected to the cleaning head by a hose. The cleaning head is equipped with two rotary nozzles that rotate on two vertical axes. The high-pressure cleaning head is fixed at the end of a travelling lever connected with an articulated joint to the trolley and there is a double-action pneumatic lifting cylinder to control the positioning of the high-pressure cleaning head. The lifting cylinder is implemented with double action to move the lever from one position to the other and back.

All cables, hoses and towing equipment are located at the back of the trolley, the towing equipment consisting mainly of cables and/or hoses.

On the trolley is installed a video monitoring head connected through power and signal cables to an external data processing unit.

The trolley is equipped with a switch holder on which one may choose to install either the high-pressure cleaning head or the video monitoring head.

Under the trolley frame there is a suction orifice that reaches under the output plane and this orifice is connected through a suction hose to the external suction installation.

This device, given the fact that the head is fixed and only the nozzles are rotating and there are two nozzles, is less efficient at work. Furthermore, the suction device is stationary and therefore, depending on the level of processed water, it can not reach the bottom of the tank. The bumpers are not elastic and therefore in the case of shock against the wall of the tank the contact is not soft. The trolley being driven by only one motor with one drive shaft, it does not have enough power and manoeuvrability and moves in one direction only. The device is not universal since it can only clean horizontal tanks.

Technical essence of the utility model

The goal of the utility model is to create a device for cleaning of petroleum products storage tanks that can be used both for horizontal and vertical tanks and that is universal, automated and multipurpose, allowing work in small as well as in large tanks, be explosion- proof and have remote control from outside the tank to be cleaned thus minimizing the human task to simple control.

The goal is achieved by the creation of a device for cleaning petroleum products storage tanks consisting of a washing unit installed on a trolley which in operating mode is put in the tank using a mobile hoisting unit. In operating mode of the device, around the tank are disposed a control unit for the trolley, a high-pressure water pump connected to a clean water tank, a suction pump for the processed water connected to a processed water tank, and an air compressor that supplies power to the pneumatic motors and the hydraulic cylinder. One or two cameras are installed on the trolley for still pictures and video feed, as well as an integrated lamp to sweep dark tanks. The cameras are connected to a control unit located right next to the trolley control unit.

The trolley comprises a support structure consisting of a frame, running gear and drive unit. The drive unit includes two pneumatic motors each of which is connected by belt transmission to a drive shaft. On each side of each shaft there is a driven gear whereas each couple of driven gears is laterally covered by an antistatic double-toothed belt. There are two compression rollers and on the side and above each belt are installed a side protective cover and a top protective cover.

This configuration of the trolley allows it to move independently forward or backward. Each of the driven gears is equipped with a locking device allowing the trolley to move on different circle trajectories, including rotating at 360° depending on the number of locked wheels: one, two or three.

The pneumatic motors are mounted on a support and are connected to an air compressor and to the control unit.

The washing unit consists of a support fixed at the lower end to the frame and at the upper end to a washing head which, through an antistatic high-pressure water pipeline and high-pressure pump, is connected to the clean water tank. The support is fixed at an angle with a bracket to the trolley frame.

On the trolley is installed a suction unit which is connected via a processed water pipe and a processed water pump to a processed water tank. The trolley is equipped with antistatic elastic bumpers, two at the front and two at the back end of the trolley frame.

The washing head contains a body with a nozzle holder and sprinkling nozzles connected to it, the body being connected with an articulated joint to the outer end of the support. There can be between two and four nozzles. In this configuration both the body and the nozzle holder can rotate at 360° and thus work in two perpendicular planes to allow the water jet to cover more space.

On the support is mounted a hydraulic cylinder with air hoses, which is needed to position the suction device and the tube under the frame so that, depending on the level of the liquid to be sucked, the suction device can be lowered or lifted by means of the hydraulic cylinder controlled from the trolley control unit.

At the front end and the rear end of the trolley to the frame are attached the limiting antistatic bumpers which are elastic and are mounted by two at the front end and two at the rear end of the frame.

On the frame is mounted a protective cover with holes provided for the installation of the suction unit and the drive belts. At the rear end of the frame is attached a support on which are mounted quick release couplers for connection of the antistatic hoses for the pneumatic motors, the hydraulic cylinder and a drilling device.

A mobile hoisting devices is provided for the purpose of lifting the trolley and putting it inside the tank to clean whereas on the frame is installed a support with bracket required to hook the trolley.

The control unit is located right next to the control panel to improve the quality and the efficiency of tank cleaning. On the trolley frame is mounted the drilling device needed to drill the tank wall wherever repairs or dismantling of the tank is required while the suction device pumps out the contaminated liquid from the space between the inner and outer walls of the tank.

The advantages of the proposed device lie in its high productivity, shorter time for tank cleaning, and the fact that it replaces the hard and dangerous work of several workers as it is operated by a single operator. This is a mobile, optimized and compact device with simple design, and easy to transport. Furthermore, this is a universal device that can be used in small as well as in large tanks, in lying as well as in vertical tanks. It is automated, multifunctional, explosion proof, made of antistatic materials, with remote control from outside the tank to be cleaned, minimizing the human activity to simple control and supervision.

Description of the drawings

The utility model is explained by the preferred embodiment as shown on the attached drawings as follows:

Fig. 1 shows the block diagram of the device

Fig. 2 represents a top view of the trolley

Fig. 3 represents a side view of the trolley

Fig. 4 represents a top view of the washing head with the nozzle

Examples of embodiment of the utility model

As shown on Fig. 1 , the device for cleaning of petroleum products storage tanks consists of a washing unit mounted on trolley 1 which in operating mode is placed inside the tank using mobile hoisting device 32. Where the device is operating around the tank are place control unit 27 for the trolley 1 , high-pressure water pump 36 connected to clean water tank 34 and suction pump for processed water 33 connected to processed water tank 35, and air compressor 26 that supplies power to the pneumatic motors 8 and the hydraulic cylinder 14. On the trolley 1 are mounted two cameras 16 for still pictures and for videos and to one of the cameras 16 is attached lamp 15 for integrated sweeping of dark tanks. The cameras are connected to control panel 28 located right next to control unit 27 of the trolley 1.

Trolley 1 as shown on Fig. 2 and Fig. 3 consists of a support structure including frame 4, running gear and drive train. The drive train includes two pneumatic motors 8, each of which through belt transmission 9 is connected to drive shaft 12 fixed at bearing bodies 30, 31. On each side of each shaft 12 there is one gear 18 and each of the couples of gears 18 is covered laterally by antistatic double-toothed belt 7. On each belt 8 there are two pressure rollers 3 and on the side and on top of each belt 7 are mounted side protective cover 24 and top protective cover 29. This design of trolley 1 allows it to move independently forward or backward. Each of the gears 18 of the trolley 1 is equipped with a locking device which allows the trolley to move along different circular trajectories, including rotating at 360 ° depending on the number of locked wheels: one, two or three. The pneumatic motors 8 are mounted on support 23 and are connected to air compressor 26 and to the control unit 27.

The washing unit consists of support 17 firmly fixed at the lower end to the frame 4 and connected at the upper end to washing head 5 which is connected through high- pressure water line 25 and the high-pressure pump 36 to the clean water tank 34. The support 17 is attached stationary and at an angle with bracket 22 to the frame 4 of the trolley 1 .

Under the frame 4 of the trolley 1 is located suction device 13 which is connected via processed water line 10 and processed water pump 33 to the processed water tank 35. The trolley one is equipped with antistatic limiting bumpers 2.

The washing head shown on Fig. 4 comprises a body 37 with nozzle holder 38 connected to it and having four sprinkling nozzles 39, the body 37 being connected by swivel joint to the outer end of the support 17. In this configuration, both the body 37 and the nozzle holder 38 can rotate at 360° and thus work in two perpendicular planes so that the water jet covers a larger surface.

On the support 17 is mounted hydraulic cylinder 14 with air hoses 19, which is required for the positioning of the suction device 13 under the frame 4 so that depending on the level of the liquid to be pumped out is controlled the lowering or lifting of the suction device 13 by the hydraulic cylinder 14 controlled from the control unit 27 of the trolley 1.

At the front end and the back end of the trolley 1 are mounted to the frame 4 antistatic limiting bumpers 2 which are elastic and are mounted in couples at the front and at the back of the frame 4.

On the frame 4 is mounted drilling device 40 which is needed to drill the inner wall of the tank whenever repair or dismantling of the tank is carried out while the suction device 13 pumps out the contaminated liquid.

On the frame 4 is mounted protective cover 6 in which holes are provided for the mounting of the suction device 13 and the belt transmissions 9. In the rear end of the frame 4 is mounted support structure 21 on which are installed pipe unions 11 for quick installation of the antistatic lines for the pneumatic motors 8, for the hydraulic cylinder 14 and for the drilling device 40.

On the frame 4 is mounted support with bracket 20 which allows the mobile hoisting device 32 to lift the trolley 1 and place it inside the tank. Operation of the utility model

The trolley 1 is taken to site, for example a petrol station where the tanks shall be cleaned. The clean water tank 34 is connected to the inlet of the high-pressure unit 36 and the outlet of this unit is connected to the washing head on the trolley 1.

The pit lid is opened using the hoisting device 32. Then the cover of the tank is opened and the remaining fuel is pumped out of the tank. After that, the tank is ventilated using an explosion-proof extracting fan. The gas medium is measured and, when it is safe, starts the cleaning of the tank itself. The washing head is prepared for work. The lines for high-pressure water, processed water and compressed air are connected to the washing head. The hoisting device 32 is used to drop the trolley 1 into the tank. The air compressor 26, the high-pressure water pump 36 and the processed water pump 33 are switched on. Water under high pressure enters the washing head 5, which is aimed toward the tank wall. On the monitor of the control unit 27 is monitored the operation of the washing device. Using the joystick on the control unit 26 the trolley is moved in the desired direction. The operating pressure of the washing water pump 36 is between 50 and 100 bars and it is monitored on the control unit 27. After the end of operation of the washing device the condition of the tank is inspected using the camera 16 and the lamp 15 on the monitor 28. Whenever it is found out that there are sections remaining unclean or that the quality of cleaning is not good enough, the trolley 1 with the washing device is started again. After the desired quality of cleaning is reached, the trolley 1 is pulled out of the tank using the hoisting device 32. The tank cover is closed and the pit lid is mounted back in place. All assembly and disassembly works are done using explosion-proof tools.