Cementing unit type TsA-320 is used to direct the cement mixture into the working well, and also serves as a solution injector into the annulus (behind the casing string). In addition, it is used to measure the liquid volume required when supplying liquid to a special cement mixing machine. Other uses of the unit are flushing and workover of wells, installation of chemical baths.
Design
The cementing unit consists of hydraulic and driving mechanism. Together they make up the main assembly of the structure - the high pressure pump. The element includes a pair of pistons, is a double-acting horizontal 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, based on a pair of roller-type bearings. The assembly is insured against axial displacement by means of thrust ball bearings mounted on spacer bushes.
Eccentricrotates on the spheres placed in the sockets of the cementing unit frame and the frame cover. It is fixed with four studs, and aggregates around the perimeter with a bolted flange. The transfer of axial forces is carried out by thrust ball bearings. In the middle part of the eccentric there is a hub, on which a bronze crown of the globoid gear is installed (fastened by pressing and bolts). Also in the design of this part, connecting rods (4 pieces) are provided, 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 rigidity. The piston part of the pump is a self-sealing type, it includes two cores with rubber seals. The piston on the rod has a cylindrical fit, is fixed with a nut and a lock nut. A rubber ring is used as a seal on the cylinder bushings.
Pressure and working flow are adjusted by means of pistons and replaceable bushings with diameters of 100, 115 and 127 millimeters. The last elements are reinforced by hardening by exposure to high frequency currents. Cylinder-type bushings are clamped by covers in valve stems using special crowns.
The piston rod at the junction of the hydraulic and drive compartments of the cementing unit is sealed with a stuffing box and cuffs in its body. This assembly is pressed by means of a pressure sleeve and a flange. On the receiving chambers of the valveboxes are provided with connectors to the suction manifold, which also 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 cementing unit TsA-320
The following are the main parameters of the technique in question.
- Loading capacity - up to 12 tons.
- The power plant capacity is 176.5 kW.
- Revolution - 2100 rotations per minute.
- Useful power - 105 kW.
- Piston travel - 250 mm.
- Globoid gear ratio - 20.
- Cementing unit chassis - KamAZ or KrAZ.
- HVD (high pressure pump) – 9 t.
- Additional engine GAZ-52A - 51.5 kW/205 Nm.
- Centrifugal pump CNS-38154 - 2950 rpm (1.54 MPa).
- Grease - automotive transmission (GOST-3781-53).
- Capacity of the measuring tank - 6 cubic meters.
- Total weight of the device - 17 tons.
- Dimensions - 10, 42/2, 7/3, 22 m.
Features
In the 320 Cementing Unit pump hydraulic compartment, a relief valve is mounted between the inch locking mechanism and the air cap on the intermediate tee. 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 the solution, this unit is protected by a separator with a workingchamber filled with oil. Valve boxes are fixed with studs.
The drive end has an oil seal to prevent dirt from entering the crosshead chamber. The outer window of the chamber is closed with a lid, the assembly pin is placed in the housing on a cone-type fit, fixed with a pressure plate and a key. The drive part of the pump is lubricated by a rotary pump driven by a worm gear. Oil is supplied to the working part through a special filter through tubes to the eccentric shaft and crosshead. On crank heads, the bearings are splash lubricated.
Operation
During the operation of the TsA-320 cementing unit, one should observe the information given by the pressure gauge and the state of the safety valve device. If the safety pin is sheared, the pump must be stopped until the part is replaced. The appearance of extraneous knocks in the hydraulics of the pump indicates a malfunction of the valves or seals. Urgent action needs to be taken to correct the problem.
You also need to regularly check oil seals, cylinder bushings, rods, tightening them in a timely manner, avoiding distortions. Clamping of the valve box glands is unacceptable, since they are equipped with self-sealing cuffs. In case of leakage, the stuffing box can be tightened without force.
Safety
In the Russian Federation, the cementing unit is often used in harsh climatic conditions. Forsafety, it is necessary to ensure timely inspection of working bodies and elimination of identified malfunctions.
Attention must be paid to all flange connections present in the pump and manifold hydraulics. The leak must be repaired immediately. You should also observe the operation of the mechanisms of the drive part of the unit, the power take-off box. When squeaks, knocks and other extraneous sounds appear, you need to identify their causes and eliminate the problems that have arisen.
It is necessary to observe the condition of the lubricating parts, including the correct lubrication. The oil temperature must not exceed 105 in the take-off box and 115 degrees Celsius in the pump.
Recommendations
If the work site has a slope, special stops are placed under the wheels of cementing machines.
The equipment in question should be positioned in accordance with the climate, terrain, type of tower (in each case).
It is forbidden to mount cementing units under power lines that are energized. The location of the equipment is carried out by the cab to the windy side in order to avoid the ingress of mortar particles and cement dust into the driver's workplace when loading the bunker. The equipment should be installed so that the measuring tanks are facing the rig.
