Cementing unit of type -320 is used to direct the grouting mixture into the working well, and also serves as a supercharger of the solution in the annulus (behind the casing). In addition, it is used to measure the liquid volume required when supplying liquid to a special cement mixing machine. Other directions of use of the unit are flushing and overhaul of wells, installation of bathtubs from chemicals.
Design
The cementing unit consists of a hydraulic and drive mechanism. Together they make up the main assembly - the high pressure pump. The element includes a pair of pistons, is a horizontal double-acting pump , serves to supply cement and clay solutions to the well.
Drive part
In the lower compartment of the crankcase, which is also an oil bath, a globoid worm is provided, supported by a pair of roller type bearings. From axial displacement, the assembly is insured by thrust ball bearings mounted on spacer bushings.
The eccentric rotates on spheres located in the nests of the skeleton of the cementing unit and the bed cover. It is fixed with four studs, and around the perimeter it aggregates with a flange on bolts. Axial forces are transmitted by thrust ball bearings. In the middle part of the eccentric there is a hub on which the bronze crown of the globoid gear is mounted (fastened by pressing and bolts). Also in the construction of this part are connecting rods (4 pieces), cast together with the shaft and located at right angles to each other.
Hydraulics
The valve steel box of the cementing unit is cast from a pair of blocks that are welded together for stiffness. The piston part of the pump is a self-sealing type; it includes two cores with rubber seals in its design. The piston on the rod has a cylindrical fit, fixed with a nut and locknut. A rubber ring is used as a seal on cylinder liners.
Pressure and working feed are adjusted by means of pistons and replaceable sleeves with diameters of 100, 115 and 127 millimeters. The latter elements are reinforced by quenching by exposure to high frequency currents. Cylinder-type bushings are clamped by covers in valve pads using special crowns.
The piston rod at the point of connection of the hydraulic and drive compartment of the cementing unit is sealed with an oil seal and cuffs in its body. The pressing of this unit is carried out by means of a pressure sleeve and a flange. On the receiving chambers of the valve boxes, connectors are provided with an intake manifold, which simultaneously serves as a support for the hydraulic part. The pump is equipped with four suction and the same number of discharge valves. Their design and dimensions are identical to each other.
Technical characteristics of the cementing unit -320
Below are the main parameters of this technique.
- The carrying capacity is up to 12 tons.
- Power plant power - 176.5 kW.
- Speed - 2100 rotations per minute.
- Useful power - 105 kW.
- Piston movement - 250 mm.
- The gear ratio of the globoid is 20.
- The chassis of the cementing unit is KamAZ or KrAZ.
- High pressure pump (high pressure pump) - 9 t.
- Additional engine GAZ-52A - 51.5 kW / 205 Nm.
- Centrifugal pump type TsNS-38154 - 2950 rpm (1.54 MPa).
- Greasing - transmission automobile (GOST-3781-53).
- The capacity of the measuring tank is 6 cubic meters.
- The total mass of the device is 17 tons.
- Dimensions - 10.42 / 2.7 / 3.22 m.
Features
In the hydraulic compartment of the pump of the cementing unit 320, a safety valve is mounted on the intermediate tee between the inch locking mechanism and the air cap. Its purpose is to limit the pressure that the pump creates. For control, there is a pressure gauge mounted on the supercharger manifold. From the ingress of solution, this unit is protected by a separator with a working chamber filled with oil. Valve boxes are fixed with studs.
An oil seal is provided in the drive section to prevent dirt from entering the crosshead chamber. The external window of the camera is closed by a lid, the knot pin is placed in the housing on the cone- type fit , fixed with the help of a pressure bar and a key. The drive part of the pump is lubricated by a rotary pump driven by a worm gear. The oil in the working part is fed through a special filter through the tubes to the eccentric shaft and crosshead. On crank heads, bearings are lubricated by spraying.
Exploitation
When operating the cementing unit CA-320, one should observe the information issued by the pressure gauge and the state of the safety valve device. If the safety pin is cut off, the pump must be stopped before replacing the part. The appearance of extraneous knocks in the pump hydraulics indicates a malfunction in the valves or seals. Urgent action is required to resolve the problem.
You also need to regularly check the seals, cylinder liners, rods, pulling them up in a timely manner, avoiding distortions. Pinching the valve box seals is not permissible as they are equipped with self-sealing cuffs. When leaking, the gland can be tightened without effort.
Security
In the Russian Federation, a cementing unit is often used in harsh climatic conditions. For safety, it is necessary to ensure timely inspection of the working bodies and the elimination of identified malfunctions.
Pay attention to all flange joints present in the pump and manifold hydraulics. Leak must be fixed immediately. You should also monitor the operation of the mechanisms of the drive part of the unit, power take-off. When squeaks, knocks and other extraneous sounds appear, it is necessary to identify their causes and eliminate the problems that have arisen.
It is necessary to monitor the health of the lubricating parts, including the correct lubrication. The oil temperature should not exceed 105 in the selection box, and 115 degrees Celsius in the pump.
Recommendations
If the working platform has a slope, special stops are placed under the wheels of cementing machines.
The equipment under consideration should be located in accordance with the characteristics of the climate, topography, type of tower (in each case).
It is forbidden to mount cementing aggregates under power lines that are energized. The arrangement of the equipment is performed by the cab to the windy side in order to prevent particles of mortar and cement dust from entering the driver's workplace when loading the hopper. The equipment should be installed so that the measuring tanks are facing the rig.